UL 746B
Polymeric Materials – Long Term Property Evaluations
NOVEMBER 3, 2011 − UL 746B
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UL Standard for Safety for Polymeric Materials – Long Term Property Evaluations, UL 746B Third Edition Edition,, Dated August 28, 1996 1996 SUMMARY OF TOPICS These revisions to ANSI/UL 746B are being issued to adopt the following requirements: Generic Thermal Index for Polyether Ether Ketone (PEEK) Generic Gener ic Therm Thermal al Index for poly(T poly(TFE/HFP/ FE/HFP/VDF) VDF) Text that has been changed in any manner or impacted by UL’s electronic publishing system is marked with a vertical line in the margin. Changes in requirements are marked with a vertical line in the margin and are followed by an effective date note indicating the date of publication or the date on which the changed requirement becomes effective. The new and revised requirements requirements are subst substantial antially ly in accor accordance dance with Propo Proposal(s sal(s)) on this subject dated July 29, 2011 and September 16, 2011. All rig rights hts reserved reserved.. No par partt of thi this s pub publica licatio tion n may be rep reprod roduce uced, d, sto stored red in a ret retrie rieval val sys system tem,, or transmitte trans mitted d in any form by any means means,, elect electronic ronic,, mecha mechanical nical photocopying, photocopying, recording, or other otherwise wise without prior permission of UL. UL provi provides des this Standard ″ as as is″ without without warranty of any kind, either expressed or implied, including but not limited to, the implied warranties of merchantability or fitness for any purpose. In no eve event nt wil willl UL be liab liable le for any spe specia cial, l, inc incide identa ntal, l, con conseq sequen uentia tial, l, ind indire irect ct or sim similar ilar damages, damages, including loss of profits, lost savings, loss of data, or any other damages arising out of the use of or the inability to use this Standard, even if UL or an authorized UL representative has been advised of the possibility of such damage. In no event shall UL’s liability for any damage ever exceed the price paid for this Standard, regardless of the form of the claim. Users of the electronic versions of UL’s Standards for Safety agree to defend, indemnify, and hold UL harmless from and against any loss, expense, liability, damage, claim, or judgment (including reasonable attorney’s fees) resulting from any error or deviation introduced while purchaser is storing an electronic Standard on the purchaser’s computer system. The requirements in this Standard are now in effect, except for those paragraphs, sections, tables, figures, and/or other elements of the Standard having future effective dates as indicated in the note following the affected aff ected item. The prior text for requi requiremen rements ts that have been revis revised ed and that have a futur future e eff effectiv ective e date are located after the Standard, and are preceded by a ″ SUPERSEDED SUPERSEDED REQUIREMENTS″ notice. notice.
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NOVEMBER 3, 2011 − UL 746B
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AUGUST 28, 1996 (Title Page Reprinted: November 3, 2011) 1
ANSI/UL 746B-2011
UL 746B Standard for Polymeric Materials – Long Term Property Evaluations First Edition – September, 1975 Second Edition – June, 1979 Third Edition August 28, 1996 This ANSI/UL Standard for Safety consists of the Third Edition including revisions through November 3, 2011. The most recent designation of ANSI/UL 746B as an American National Standard (ANSI) occurred on November 2, 2011. ANSI approval for a standard does not includ inc lude e the Cov Cover er Pag Page, e, Tra Transm nsmitt ittal al Pag Pages, es, Tit Title le Pag Page, e, or ef effec fectiv tive e dat date e information. Any other portions of this ANSI/UL standard that were not processed in acc accord ordanc ance e wit with h ANSI ANSI/UL /UL requireme requirements nts are not noted ed at the beginning beginning of the impacted sections. Comments Comme nts or pro propos posals als for rev revisi isions ons on any part of the Standar Standard d may be submit sub mitted ted to UL at any time. Proposal Proposals s sho should uld be sub submit mitted ted via a Pro Propos posal al Request in UL’s On-Line Collaborative Standards Development System (CSDS) at http://csds.ul.com. UL’s Standards Standards for Safety are copyr copyrighte ighted d by UL. Neithe Neitherr a print printed ed nor elect electronic ronic copy of a Standard should be altered in any way. All of UL’s Standards and all copyrights, ownerships, and rights regarding those Standards shall remain the sole and exclusive property of UL. COPYRIGHT © 2011 UNDERWRITERS LABORATORIES LABORATORIES INC.
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POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
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AUGUST 20, 2009
AUGUST 20, 2009
POLYMERIC MATERI AL ALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
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CONTENTS
INTRODUCTION 1 2 3 4 5
Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 .5 Supplementary Te Test Pr Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 .5 Characteristics of Polymeric Materials ...................................................6 Use of of Po Polymeric Ma Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 .6
DETERMINATION OF THE RELATIVE THERMAL INDICES OF POLYMERIC MATERIALS 6 7 8 9
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 .7 Relative Th Thermal In Index – Based Up Upon Hi Historical Re Record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 Rela Re lati tive ve The Therm rmal al Ind Index ex – Base Based d Upon Upon Lon Longg-Te Term rm The Therm rmal al-A -Agi ging ng Pro Progr gram ams s . . . . . . . . . . . . . . . .1 .10 0 Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 . 11 9.1 Ovens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 . 11 10 Scope of of Te Test Pr Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 10.1 Selection of test properties ....................................................12 11 Property-Evaluation Te Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12A 11.1 Ge G eneral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12A 11.2 Ch C hoice of end-point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12A 11A Sampling Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12B 12 Selection of Oven Temperatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12B 13 Selection of of Co Control Ma Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 14 Specimens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 . 14 15 Thermal Aging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 . 14 16 End-of-Life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 . 17 16.1 Primary pr properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 16.2 Se Secondary properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 17 Pr P roof Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 18 Analysis an and Ev Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 19 Re Rela late ted d Mat Mater eria iall – Cov Cover erag age e of of Var Varia iattio ions ns in in Ma Mate terria iall Com Compo posi siti tion on . . . . . . . . . . . . . . . . . . . . . . .23 19.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 . 23 19.2 Thermoplastic ma materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 19.3 Thermosetting mo molded ma materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 27 20 Aging, Specimen, and Check-Test Schedules ..........................................28 20.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 . 28 20.2 Polypropylene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 . 28 20.3 Co Coating powders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 20A Fixed Time Sampling Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36 20A.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 . 36 20A.2 Screening Pr Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 .36A 20A.3 Remainder of Fixed Time Sampling Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36B RELATIVE THERMAL INDEX CLASS 21 Assignment of Temperature Cl Classifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36B
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POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
NOVEMBER 28, 2001
MARKING 22 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
SUPPLEMENT SA - FOLLOW-UP INSPECTION INSTRUCTIONS
INTRODUCTION SA1 SA 2 SA3 SA4 SA5 SA 6
Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SA1 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SA1 Gl Responsibility of the Manufacturer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SA2 Responsibility of of th the Fi Field Re Representative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SA2 Selection of of Sa Samples fo for Fo Follow-Up Te Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SA3 Follow-Up Te Test Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SA3
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NOVEMBER 29, 2000
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INTRODUCTION 1 Sco Scope pe 1.1 These requirement requirements s cover long-term long-term test procedures procedures to be used for the evaluation of materials used for parts intended for specific applications in end products. 1.2 Tog Togeth ether er wit with h the Sta Standa ndards rds men mentio tioned ned in Sup Supple plemen mentar tary y Tes Testt Pro Proced cedure ures, s, Sec Sectio tion n 3, the these se investig inve stigatio ations ns prov provide ide dat data a with resp respect ect to the phys physical ical,, elec electric trical, al, flam flammabi mability lity,, ther thermal, mal, and othe otherr properties of the materials under consideration and are intended to provide guidance for the material manufacturer, the molder, the end-product manufacturer, safety engineers, and other interested parties. 1.3 A produ product ct that contains features, features, characteristics characteristics,, comp component onents, s, mate materials, rials, or syste systems ms new or diff different erent from those covered by the requirements in this standard, and that involves a risk of fire or of electric shock or inju injury ry to per persons sons shal shalll be eval evaluat uated ed usin using g appr appropri opriate ate addi additio tional nal com compone ponent nt and endend-pro product duct requir req uireme ements nts to mai mainta ntain in the level of saf safety ety as ori origina ginally lly ant anticip icipate ated d by the intent of thi this s sta standa ndard. rd. A product prod uct whos whose e fea feature tures, s, char characte acterist ristics, ics, comp componen onents, ts, mat materia erials, ls, or syst systems ems confl conflict ict with spec specific ific requirements or provisions of this standard does not comply with this standard. Revision of requirements shall be proposed and adopted in conformance with the methods employed for development, revision, and implementation of this standard. 1.3 revised November 29, 2000
2 Refer References ences 2.1 Any undated reference reference to a code or standard standard appearing in the requirements requirements of this standard shall be interpreted as referring to the latest edition of that code or standard. 3 Supple Supplement mentary ary Test Procedures Procedures 3.1 The Standard Standard for Tests for Flammability Flammability of Plastic Materials Materials for Parts in Devices and Applia Appliances, nces, UL 94, covers flammability flammability of polym polymeric eric materials materials used for parts in device devices s and appliances. appliances. The Standard for Polymeric Polym eric Materials – Short Term Prope Property rty Evaluations, Evaluations, UL 746A, contains short-term short-term test proce procedures dures to be used for the evaluation of materials used for parts intended for specific applications in electrical end products. The Standard for Polymeric Materials – Fabricated Parts, UL 746D, contains requirements for traceability and performance of parts molded and fabricated from polymeric materials. 3.1 revised February 22, 2000
3.2 Progr Programs ams for the investigation investigation of material material part modifications, modifications, such as the plating of plast plastics ics or the use of flam flame-re e-retar tardant dant paints, are con contain tained ed in the Stan Standard dard for Poly Polymer meric ic Mat Materia erials– ls– Use in Elec Electric trical al Equipment Evaluations, UL 746C. 3.3 Data concerning the effect of various various environments and contaminants upon the properties properties of materials can also be obtai obtained ned through standard test procedures. procedures. The more comm commonly only used proce procedures dures are briefly described in the Standard for Polymeric Materials– Short Term Evaluations, UL 746A. 3.4 Test procedures procedures are provided in the Standard Standard for Polym Polymeric eric Materials Materials – Use in Electr Electrical ical Equipment Equipment Evaluation, UL 746C, for the evaluation of polymeric materials in specific applications in end products. These test procedures include references to the data obtained from the standard property tests as well as other practical practical means of evalua evaluation. tion.
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POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
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3.5 Req Requir uireme ements nts for material materials s tha thatt hav have e bee been n mod modifie ified d to mat match ch the requireme requirements nts of a spe specifi cific c application, including the use of recycled and regrind materials, the use of additives and colorants, and the blending of two or more materials, materials, are descr described ibed in the Standard for Polymeric Materials Materials – Fabric Fabricated ated Parts, UL 746D. 4 Chara Characteri cteristics stics of Polymeric Materials Materials 4.1 Polymeric materials include thermoplastic, thermosetting, thermosetting, and elastomeric elastomeric materials. A thermoplastic material can be easily softened and resoftened by repeated heating. A thermosetting material cures by chemical reaction and, when cured, cannot be resoftened. An elastomeric material is capable of being stretched at room temperature to at least twice its length under low stress and recovers to its original length when released from the stress. 4.2 Characteristics of polymeric materials materials that necessitate additional consideration include: a) Mold stress stresses es b) Insul Insulating ating quality quality c) Resist Resistance ance to ignition ignition d) Extinguishing characteristics e) Produ Production ction of smoke smoke and gases f) Mecha Mechanical nical Strength Strength g) Compa Compatibili tibility ty with solvents solvents h) Melti Melting ng or distortion distortion i) Cold flow, if under under stress stress j) Fuel contribution k) Dimen Dimensional sional stability stability 5 Use of Polymeric Polymeric Materials Materials 5.1 The reductio reduction n to an acc accept eptabl able e lev level el of the risks of ele electr ctric ic sho shock, ck, fire, and personal personal inj injury ury from electrical equipment depends upon the selection of materials, design, and processing of parts as well as the assembly, mounting, and relative positions of these parts. 5.2 The properti properties es nee needed ded by ind indivi ividua duall par parts ts are defined defined by the function function or fun functi ctions ons of the part. An enclos enc losure ure,, for exa exampl mple, e, mus mustt ord ordina inarily rily be des design igned ed to wit withst hstand and mec mechan hanical ical abu abuse. se. Acc Accord ording ingly, ly, a material known to have substantial impact strength would normally be used although a material that has a lower impact strength, but is reinforced, might also be acceptable. 5.3 Electrical equipment of necessity employs employs many materials that usually usually have divergent properties. The ability to match the demands of the application with the characteristics of a material as well as the ability to compare the properties of one material with those of another can lead to an acceptable selection of materials.
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POLYMERIC MATERI AL ALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
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5.4 Th 5.4 The e in info form rmat atio ion n ga gain ined ed fr from om th the e da data ta ob obta tain ined ed fr from om th thes ese e te test sts s ca can n be us used ed as an ai aid d in th the e evaluation of electrical equipment using parts made of polymeric materials. Knowledge of materials can be obtained from an analysis of data from standard tests conducted on small specimens. DETERMINATION OF THE RELATIVE THERMAL INDICES OF POLYMERIC MATERIALS 6 Gen Genera erall 6.1 A rel relati ative ve the therma rmall inde index x of a mat materi erial al is an indicatio indication n of the materia material’s l’s ability ability to retain retain a par partic ticula ularr property (physical, electrical, etc.) when exposed to elevated temperatures for an extended period of time. It is a measure of the material’s thermal endurance. For each material, a number of relative thermal indice ind ices s can be est establ ablish ished, ed, each ind index ex rel relate ated d to a spe specifi cific c pro proper perty ty and a spe specifi cific c thi thickn ckness ess of the material. 6.2 In determining determining the relative thermal thermal index of a mate material, rial, the basic concepts concepts to be followed are stated in the Inst Institut itute e of Elect Electrica ricall and Elec Electro tronics nics Engineers Engineers Spec Specifica ification tions s No. 1, Gene General ral Prin Principl ciples es for Temper Tem peratu ature re Lim Limits its in the Rat Rating ing of Ele Electr ctrica icall Equ Equipm ipment ent;; No. 98, Guid Guide e for the Pre Prepar parati ation on of Tes Testt procedures proce dures for the Thermal Evaluation Evaluation of Elect Electrical rical Insulating Insulating Mater Materials; ials; No. 101, Guide for the Stat Statistica isticall Analysis of Thermal Life Test Data. 6.3 The relative relative thermal index of a mater material ial is to be based upon an evalua evaluation tion of long-term long-term thermal-aging thermal-aging data dat a obt obtain ained ed und under er the pro progra gram m des descr cribe ibed d in Rel Relati ative ve The Therma rmall Ind Index ex – Bas Based ed Upo Upon n Lon Longg-Ter Term m Thermal-Aging Programs, Section 8. Thermal indices on a generic basis have been established through knowled kno wledge ge of ext extens ensive ive field field-se -servi rvice ce rec record ords, s, as outl outlined ined in Rela Relative tive Thermal Thermal Ind Index ex – Bas Based ed Upon Historical Record, Section 7. Relative thermal indices may also be established based upon a study and evaluation of the interrelationship of all of the data mentioned in Supplementary Test Procedures, Section 3, which can also be coupled with knowledge concerning the material’s performance in insulating systems gained through experience experience or longlong-term term aging tests tests.. 6.4 A co 6.4 comp mpari arison son of th the e the therm rmalal-agi aging ng ch char aract acter erist istics ics of on one e ma mate teria riall of pr prove oven n fie field ld ser servic vice e at a particular temperature level with the thermal-aging characteristics of another material with no field service history provides a means for estimating the relative thermal index level at which the second material might also provide accep acceptable table field servi service. ce. 6.5 Anoth Another er explanation explanation of a relative thermal thermal index is the maxim maximum um temperature temperature below which a mate material rial maintains its characteristics over a reasonable period. This relative thermal index serves the very great need to evaluate materials that are exposed to heat sources in electrical products in which they are not used as part of an insulating system and in which they are not subjected to other major degradation influen infl uences ces.. It is to be ass assume umed d tha thatt neit neither her excessive excessively ly long nor exc excess essive ively ly sho short rt dut duty y cyc cycles les are involved. 6.6 To be valid for use in a specific application application,, a relat relative ive thermal thermal index of a mater material ial must be established established by a study of the degradation rates of all properties that are relied upon in that application. As a corollary to this principle, more than one relative thermal index can be assigned to a material depending on the relative degradation rates of the properties of the material and depending on which of these properties are considered consid ered in estab establishin lishing g the indice indices. s.
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POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
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7 Relat Relative ive Thermal Index – Based Upon Historical Historical Record 7.1 Table 7.1 presents presents a list of materials, materials, each of which is assigned a relative thermal thermal index based on accept acc eptabl able e ser servic vice e exp experi erienc ence, e, the che chemic mical al str struct ucture ure of the mat materi erial, al, and a kno knowle wledge dge of the performance of the material in tests of insulating systems and electrical equipment. The assigned relative thermal index is applicable to each member of the generic material class. 7.2 Unless otherwise otherwise indicated indicated in Table 7.1, the generic thermal thermal index of a material is to be consid considered ered 50°C (122°F). 7.3 Unless otherwise otherwise indicated indicated in Table 7.1, the generic thermal index of a mater material ial is indepe independent ndent of thickness and pigmentation. Table 7.1 Relative thermal indices based upon past field-test performance and chemical structure a Table 7.1 revis revised ed November 3, 2011 Material
ISO designation
Generic thermal index,°C
(PA)
65
(PC)
80
(PC/Siloxane)
80
molding resinb
(PET)
75
film (0.010 inch, 0.25 mm)
(PET)
105
Polyamide (Type 6, 11, 12, 66, 610, or 612 nylon)b b
Polycarbonate
Polycarbonate/Siloxane Copolymer k Polyethylene terephthalate –
Polybutylene (polytetramethylene) terephthalateb Polyphenylene Oxide j Polypropyleneb,h
(PBT)
75
(PPE – PS)
65
(PP)
65
Polyetherimideg
–
105
Polyethersulfone
PES
105
(PEEK)
130
(PPS)
130
(PI)
130
(PF)
150
Polyether Ether Ketone Polyphenylene
Sulfide b
Polyimide film (0.25 mm, 0.010 inch max) Molded
phenolicc c,d
Molded melamine and Molded melamine/phenolicc,d – specific gravity < 1.55
13 0
specific gravity ≥ 1.55
150
Polytetrafluoroethylene Polychlorotrifluoroethylene Fluorinated ethylene propylene Fluorinated ethylene propylene Poly(tetrafluoroethylene, hexafluoropropylene, hexafluoropropyle ne, vinylidenefluoride)l Ethylene/Tetraflouroethylene Urea Formaldehyde
c
Acrylonitrile – butadiene – styrene b Silicone – molding
(PTFE)
180
(PCTFE)
150
(FEP)
150
(FEP)
150
(TFE/HFP/VDF)
130
(E/TFE)
105
(UF)
100
(ABS)
60
resinc,d
150
Silicone rubber – molding resin
(SIR)
Table 7.1 Continued on Next Page
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Table 7.1 Continued Material room-temperature vulcanizing or heatcured paste
ISO designation
Generic thermal index,°C
(RTV)
105
Epoxy – molding resinc,d
130
powder coating materials casting or potting
105
resinb,i
(EP)
Molded diallyl phthalatec,d
90 130
Molded unsaturated polyesterc,d
(UP)
alkyd (AMC), bulk (BMC), dough (DMC), sheet (SMC), thick (TMC), and pultrusion molding compounds Liquid crystalline thermotropic aromatic polyesterf
(electrical)
10 5 e
(mechanical)
130
(LCP)
130
Ligno-cellulose laminate
60
Vulcanized fiber
90
Cold-molded phenolic, melamine or melamine-phenolic compoundsd – specific gravity< 1.55
130
specific gravity ≥ 1.55
150
Cold-molded inorganic (hydraulic-cement, etc.) compounds
200
Integrated mica, resin-bonded – epoxy, alkyd or polyester binder
130
phenolic binder
150
silicone binder
200
a
Generic thermal index is for homopolymer and for the compounding of the same type or relative resins, either grafted or ungrafted only, unless a specific copolymer or blend is indicated. In the case of alloys, the lowest generic index of any component compo nent shall be assig assigned ned to the composite. composite. The term ″ grafted″ means means all of the monomer reacts to form a polymer, and the polymer chain forms a chemical bond. The term ″ ungrafted″ means means that the two types of polymer chains entwine with each other by mechanical blending to form a chemical composite. b
Includes glass-fiber reinforcement and/or talc, asbestos, mineral, calcium carbonate, compounding of the same type of resins, either grafted or ungrafted and other inorganic fillers. c
Includes only compounds molded by high-temperature and high-pressure processes such as injection, compression, pultrusion, and transfer molding and match-metal die molding; excludes compounds molded by open-mold or low-pressure molding processes such as hand lay-up spray-up, contact bag, filament winding, rotational molding, and powder coating (fluidized bed, electrostatic spray, hot dip, flow coating). d
Includes materials having filler systems of fibrous (other than synthetic organic) types but excludes fiber reinforcement systems using resins that are applied in liqui systems liquid d form. Synthetic Synthetic organic fillers are to be cons considere idered d accep acceptable table at temperatures not greater than 105°C. e
Except 130°C generic thermal index i f the material retains at least 50% of its unaged dielectric strength after a 504-hour exposure at 180°C in an air circulating exposure circulating oven. Spec Specimens imens are to be tested in a dry, as molded molded,, condi condition. tion. Specimens Specimens that are removed from the oven are to be cooled over desiccant for at least 2 hours prior to testing. f
Includes only wholly aromatic liquid crystalline thermotropic polyesters; wholly aromatic polyester/amides and wholly aromatic polyester/ethers; excluding amorphous, lyotropic and liquid crystalline aliphatic-aromatic polyesters which are aliphatic in the backbone chain or main chain, and substituted aromatic polyesters (except for methyl or aromatic). g
Includes only polyetherimide molding resin.
h
Includes polypropylene copolymers containing not more than 25% ethylene comonomer, by weight.
i
Multi-part liquid epoxy materials incorporating acid anhydride or aromatic amine curing agents receive a 130°C 130°C generic thermal index.
Table 7.1 Continued on Next Page
10
POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
NOVEMBER 3, 2011
Table 7.1 Continued Material
ISO designation
Generic thermal index,°C
j
Includes only those polyphenylene oxide materials in which the PPO component is not less than 30% of the total composition by weight and that have a Heat Deflection composition Deflection Temperature Temperature of at least 70°C at a load (fiber stress) stress) of 1.80 M Pa (264 psi). k
PC/Siloxane Copolymers in which siloxane comprises less than, or equal to, 5% of the total material composition by weight. l
Must have a minimu minimum m peak meltin melting g point of 160 °C, with less than 25% VDF monomer by weight and the remainder remainder being fully fluorinated monomers.
8 Relat Relative ive Thermal Index – Based Upon Long-Term Long-Term Thermal-Aging Thermal-Aging Programs Programs 8.1 The properties properties of a polymeric material material degrade with time when expos exposed ed to vario various us environments. environments. A prime cause of degradation is exposure to heat. 8.2 The behavior behavior of a mater material ial that is subjected subjected to thermal aging in air cannot be assumed assumed to be the same as its beh behavi avior or und under er ser servic vice e con condit dition ions; s; how howeve ever, r, a kno knowle wledge dge of the the therma rmal-a l-aging ging behavior behavior of a material can be used as a basis for comparison of polymeric materials. 8.3 The thermal-aging thermal-aging characteris characteristics tics of a material can be determined determined by measu measuring ring the changes in its properties to a predetermined level by aging test specimens at each of several elevated temperatures; plotti plo tting ng log of tim time-t e-to o the spe specifi cified ed end poi point nt at eac each h tem temper peratu ature re aga agains instt the rec recipr iproca ocall of abs absolu olute te temperatu temp erature; re; and plott plotting ing the bestbest-fit fit straight line by regre regression ssion analysis. analysis. The plotted line is often referred referred to as the life-line of a material. 8.3 revised August 20, 2009
8.3.1 Unless specified specified otherwise, otherwise, a 50-pe 50-percent rcent loss of property value due to therm thermal al degradation degradation shall be considered as the property end point. 8.3.1 added August 20, 2009
8.4 The manufacture manufacturerr of the material material is respo responsible nsible for: a) The estimation estimation of the diff different erent applications applications in which the material can be used, and b) The selection selection of the tempe temperatu ratures, res, properties, properties, and thicknesses thicknesses that are to be measu measured red during the thermal-aging investigation. If products of decomposition of one material are suspected of having an adverse effect on the other, for example, if two materials are not of the same generic type or if a flame retardant or other additive in one material adversely affects the other material, then they should not be aged simultaneously in the same oven. It is desirable that the oven exhaust be positively vented outside the test facility.
OCTOBER 15, 2004
POLYMERIC MATERI AL ALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
11
9 Appar Apparatus atus 9.1 Ove Ovens ns 9.1.1 The thermal-aging thermal-aging ovens that are used in the aging program shall comply with the Standard Test Methods for Forced-Convection Laboratory Ovens for Evaluation of Electrical Insulation, ASTM D 5374-93 a, and with the Standard Specification for Forced-Convection Laboratory Ovens for Evaluation of Electrical Insulat Ins ulation, ion, ASTM D 5423 5423-93 -93 a fo forr Typ Type e I ove ovens, ns, pr prima imaril rily y wit with h res respe pect ct to Rat Rate e of Ven Venti tilat lation ion,, Se Sett Temperature, Temperature Variation and Thermal Lag Time. Exception: Exceptio n: Non airair-circ circulat ulating ing stat static ic oven ovens s and/ and/or or for forcedced-draf draftt circ circulat ulatinging-air air conv convecti ection on oven ovens s not capable of providing replacement of fresh air at the rate of not less than 5 changes per hour may be employed provided that: a) The oven is capabl capable e of maint maintaining aining the Set Tempe Temperatur rature, e, Temperature Temperature Variation Variation and a Thermal Lag Time described in ASTM D 5423-93 . The Thermal Lag Time is not applicable if the oven is not subjected to frequent openings, and if the ratio of oven aging time to open-oven time is large. b) The products products of the material material decom decomposit position ion are not expected expected to further degrade degrade the polymer – in other words, shall not be autocatalytic, and c) A control material material of known performance performance is aged in the same ovens and for the same time duration as the candidate materials. a
ASTM standards are available from the American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, Drive, Conshohocken, PA 19428. 9.1.1 revised October 15, 2004
9.1.2 The oven temperature temperature control control is to be capabl capable e of longlong-term term operation. operation. It is desirable that the oven be provided with a timer and also with an oven-temperature cut-off to prevent loss of specimens, loss of data, or loss of test continuity. Ordinarily, at least four ovens of applicable capacity are needed to contain the aging specimens; however, two ovens can be effectively used by completing the work at the two higher hig her the therma rmal-ag l-aging ing tem temper peratu atures res firs firstt and the then n swi switch tching ing the ove oven n set settin tings gs to the two low lower er thermal-aging temperatures. 9.1.3 Tem 9.1.3 Temper peratu atures res for hea heatt agi aging ng are to be acc accura uratel tely y con contro trolled lled and mon monito itored red.. At the start of the program, oven temperatures are to be checked frequently. The use of several thermocouple locations to check variations throughout the ovens is required. As the test progresses, monitoring can be done less frequently.
12
POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
JULY 6, 2011
10 Scope of Test Test Programs Programs 10.1 Select Selection ion of test properties properties 10.1.1 10.1. 1 The specific properties properties to be evaluated in the therm thermal-agi al-aging ng program shall be deter determined mined.. 10.1.2 The contemplated 10.1.2 contemplated applications applications of the material material (as intended by the manuf manufactur acturer er of the material), material), the flammability characteristics, and the physical and electrical properties that the material needs to have for these applications are to be considered. 10.1.3 Tab 10.1.3 Table le 10. 10.1 1 pro provid vides es a list of pro proper pertie ties s tha thatt can serve as an aid in the determin determinati ation on of the properties to fall within the scope of the investigation. The properties are to be as nearly as possible representative of the properties required for the end application. Table 10.1 List of properties and test methods Table 10.1 revised July 6, 2011 Property a
Test Method
Mechanical Properties Maximum Tensile Stress or Flexural Strength
UL 746A
Tensile Impact, Izod Impact, or Charpy Impactb
UL 746A
Electrical Properties Dielectric Strength
UL 746A
Flammability Properties Vertical Burning
UL 94
a
The list of properties given in this table is not complete. Other properties that are critical in a particular end-use application are to be included in the program. b
For unaged materials that do not exhibit break upon impact testing, the RTI Mechanical Impact can not be determined and therefore the RTI Mechanical Impact is not applicable (N/A).
10.1.4 The results of Tensile, Charpy or Izod Impact testing 10.1.4 testing of stand standard ard specimens specimens in eithe eitherr the nomina nominall 3 mm or 4 mm thickness, as appropriate for the specified test method, can be considered representative of the tes testing ting of redu reduced ced thi thickne cknesses sses provided provided suc such h redu reduced ced thi thickne cknesses sses have bee been n eva evaluat luated ed for non-impact non-i mpact mechanical mechanical prope properties rties.. The assign assigned ed ther thermal mal indice indices s for impact prope properties rties in the reduc reduced ed thicknesses shall be lowered by an offset equal to the corresponding lower offset, if any, of the thermal indices indice s of the non-im non-impact pact properties properties at the reduced thicknesses. thicknesses. Table 10.2 illustrates illustrates a hypot hypothetic hetical al example of this offset. 10.1.4 revised September 18, 2009
SEPT SE PTEM EMB BER 18 18,, 20 200 09
POL PO LYM YMER ERIC IC MA MATE TER RIA IALS LS – LO LONG NG TE TERM RM PRO ROPE PER RTY EV EVAL ALUA UATI TION ONS S - UL 74 746 6B
12A
Table 10.2 Example of applying offset principle to assigning impact ratings Table 10.2 revised September 18, 2009 RTI
a
Min. thick. (mm)
E le c
Imp
Str
0.75c
130a
75b
90a
1.5
130
b
80
95a
3.0
130
90a
105a
Thermal indices assigned based on actual testing at thicknesses.
b
Thermal indices assigned based on the results of testing the 3.0 mm or 4.0 mm thickness, reduced by the corresponding offsets of 105°- 95°= 10°C and 105°- 90°= 15°C for the 1.5 and 0.75 mm thick offsets thickness nesses es respectively respectively.. c
Offset principle for impact ratings also applies to minimum thicknesses less than 0.75mm provided that they have been tested to Table 10.2 requirements.
11 Prope Propertyrty-Evalua Evaluation tion Tests 11.1 Gener General al 11.1.1 Table 10.1 provi 11.1.1 provides des a list of test specification specifications s that generally generally are used for property-eva property-evaluatio luation n tests. Other tests can be used if found to be acceptable for the application. 11.1.2 The tests are to monit 11.1.2 monitor or the perf performan ormance ce level for each property property as the accelerated accelerated aging of the material progresses. 11.1.3 The tests selected 11.1.3 selected are to sim simulat ulate e as clos closely ely as pos possibl sible e the field-serv field-service ice con condit ditions ions of the contemplated-use application. Some test methods can be used for only certain forms of polymerics (for example, film or sheet materials). 11.2 Choice of of end-point end-point 11.2.1 The Institute 11.2.1 Institute of Electrical Electrical and Electr Electronic onic Engineers Engineers (IEEE) standards do not specif specify y the method of determ det erminin ining g end of life life,, alth although ough several several alte alternat rnatives ives are pre present sented. ed. Fixe Fixed d prop propert erty y leve levell and percent-of-unaged property level are two of these that appear to have the most significance in relation to end-use end-u se applic applications ations.. Produc Productt design normally involv involves es the facto factor-of r-of-safe -safety ty approa approach. ch. There Therefore, fore, the relative thermal index developed by this standard is based on the assumption that a factor of safety exists in the applic applicable able physical and elect electrical rical property property requi requiremen rements. ts. It is not expec expected ted that a 50-pe 50-percent rcent loss of property due to thermal degradation results in premature risk of electric shock, fire, or personal injury. The considerations have led to the decision to report the end point at each aging temperature as the time at which a prope property rty value has decre decreased ased to 50 percent of its unaged level where quantitative quantitative evaluation evaluation test methods are available. 11.2.1 revised August 20, 2009
11.2.2 In certain applications, 11.2.2 applications, the reduction reduction to 50 perce percent nt of the initial property property value may not repre represent sent the stresses encountered in actual service. A fixed property level may be used in applications where the anticipated service stress can be defined and where consideration has been given to the expected duty cycle, cyc le, deg degree ree of det deteri eriora oratio tion n ove overr the use useful ful pro produc ductt lif life e and an acc accept eptabl able e fac factor tor-of -of-sa -safet fety. y. As an alternative, the relative thermal capability may be determined for each application using the concepts described in the Standard for Polymeric Materials– Use in Electrical Equipment Evaluations, UL 746C.
12B
POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
AUGUST 20, 2009
11A Sampl Sampling ing Programs Programs 11A.1 Two sampling techniques techniques are availa available ble for conduc conducting ting a longlong-term term thermal thermal aging invest investigatio igation: n: the Fixed Temperature Method in Sections 12 – 20 and the Fixed Time Method in Section 20A. Both methods will provid provide e the time-temperat time-temperatureure-prope property rty values needed to estab establish lish the Thermal Index Rating and assign a thermal class rating. The primary difference between the methods is in the sampling technigue employ emp loyed. ed. Since bot both h met method hods s rel rely y upo upon n a dat data a ana analys lysis is of the degradat degradation ion of sam sample ples s at var variou ious s temperatures and using specific time intervals, the results of the tests would be expected to be similar regardless of which of the two methods is selected. 11A.1 added February 22, 2000
11A.2 Both the control and the candidate materials materials shall be evaluated using the same sampling method method (Fixed (Fixe d Tempe Temperatur rature e or Fixed Time). 11A.2 added February 22, 2000
11A.3 The test specimens specimens are to be the same size and shape for both test methods. methods. 11A.3 added February 22, 2000
11A.4 All material properties properties (i.e., electrical, electrical, mechanical, mechanical, and flamm flammabilit ability) y) can be evaluated using either method. 11A.4 added February 22, 2000
11A.5 All initial 11A.5 initial (un (unage aged) d) and age aged d spe specim cimens ens are to be tes tested ted using the sam same e tes testt met method hod for eac each h property. 11A.5 added February 22, 2000
12 Select Selection ion of Oven Temperatures Temperatures 12.1 At least four oven temperature temperatures s are to be selec selected. ted. The lowest oven temperature temperature (T4) selected selected is to produce an anticipated end point of the material’s property at this temperature in not less than 5,000 hours. The highest oven temperature (T1) selected is to produce an anticipated end point of the material’s property at this temperature in not less than 500 hours. The minimum aging time criterion is applicable for each primary property evaluated. See Table 12.1. 12.1 revised August 20, 2009
12.2 Deg 12.2 Degrad radati ation on is a fun functi ction on of the agi aging ng cha charac racter terist istics ics of the par partic ticula ularr poly polymer mer.. Spec Specific ific agi aging ng temperatures cannot therefore be recommended since the test temperatures can differ for each material tested. 12.3 Sho 12.3 Shortrt-tim time e scr screen eening ing tes tests ts at var variou ious s tem temper peratu atures res can be use used d to est estima imate te the ant antici icipat pated ed end-of-life. 12.4 If degradation degradation cannot be accelerated accelerated because because of trans transition ition points points or thre threshold shold temperatur temperatures, es, and in consideration of the need for a spread between aging temperatures, it might be necessary to extend the low-temperature test (t4 in Table 12.1 ) to well beyond the usual 5000-hour minimum value indicated in note b to Table 12.1 to obtain significant data.
AUGUST 20, 2009
POLYMERIC MATERI AL ALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
13
Table 12.1 Selection of oven temperatures Table 12.1 revised August 20, 2009 Test temperature (°C)
End Point (Hours) Cycle Period a
a
Days
t1 (highest)
t2
t3
t4 (lowest)
500 min.
1,500 approx.
3,000 approx.
5,000 min.
3
7
14
28
See 14.2.
12.5 The spread between between aging temperatures temperatures is to be enough to overcome the small errors in measuring measuring and controlling temperatures, generally at least 10°C (18°F). 12.6 The reason for these test-tempera test-temperature ture limitations limitations is to provi provide de accurate data so that extrapolati extrapolation on to determine deter mine the accep acceptable table operating temperature temperature for life can be reaso reasonably nably predicted. predicted. 13 Select Selection ion of Control Material Material 13.1 A control material material is to be select selected ed and tested in the thermal-agin thermal-aging g test program in the same manner as the material under investigation. 13.2 The control material material is to be a material that has an estab established lished relative relative thermal index. Preferably Preferably,, the material is to be one with a record of good field service at its rated temperature. If possible it is to be of the same generic type as the candidate material, is to be tested in the same thickness, and is to have a relative thermal index as close as possible to that expected for the candidate material. 13.3 More than one contr control ol material may be test tested ed to insur insure e compa comparable rable performanc performance e to the candidate, candidate, but only one control will be considered in establishing the candidate’s RTI for all properties. 13.4 The control control shall be teste tested d at the same time as the candid candidate ate and conditioned conditioned in the same ovens except where the performance ranges of candidate and control are sufficiently different to necessitate differe dif ferent nt range ranges s of aging temperatures temperatures,, or where special conta contaminat mination ion proble problems ms have been demonstrated. If different ovens are necessitated because of different ranges of aging temperatures, then at least two of the four aging temperatures temperatures shall overlap and the same ovens, containing both control and candidate test specimens, shall be used at these overlapping temperatures. The property end points for both bot h the can candid didate ate and con contro troll mat materi erial al tes testt spe specim cimen en con condit dition ioned ed in the these se ove overla rlappi pping ng ove ovens ns sha shallll comply with the minimum aging times indicated in Table 12.1. 13.4 revised August 20, 2009
14
POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
AUGUST 20, 2009
14 Specim Specimens ens 14.1 The physical dimensions dimensions of the test specimens specimens are given in the test specifications specifications referred referred to in the Standard for Polymeric Materials – Short Term Property Evaluations, UL 746A. Normally, 5 specimens constitute a set; however, a greater number might be necessary if the property under evaluation exhibits scattered results. Refer to Aging, Specimen, and Check-Test Schedules, Section 20 for typical sample requirements. 14.2 For each oven temperature temperature,, there is to be an assign assigned ed cycle period. Usually Usually the cycle period for the highest temperature is to be 3 days, for the next lower temperature 7 days, for the next lower temperature 14 days, and for the lowest temperature 28 days. Refer to Table 20.2. 15 Therm Thermal al Aging Aging 15.1 To obtain a meas measureme urement nt of each of the properties properties at the end of each successive cycle cycle period for each oven-aging temperature, it might require an extremely large number of specimens inasmuch as the material generally survives more than 10 cycles of the test program. 15.2 To con 15.2 conser serve ve on the total number number of spe specim cimens ens required required,, to red reduce uce the fre freque quency ncy of mak making ing the measurements, and also to develop data near the time of 50-percent reduction of the initial property value, the procedure in 15.3 – 15.5 can be followed. 15.2A All spe 15.2A specim cimens ens are to be pre pre-co -condi nditio tioned ned for 48 hou hours rs at the lowest aging temperat temperature ure of the program to eliminate any short-term thermal effects. 15.2A added November 28, 2001
15.3 Initi Initially ally for each temperatur temperature, e, 5 sets of specim specimens ens are to be placed in the oven. At the end of the first, second, and third cycles an additional set is to be added. 15.4 At the end of the third cycle, cycle, some of the original original test specimens specimens are to be removed removed from the oven and subjected to the applicable tests. Assuming that the average property value of these specimens is greate gre aterr tha than n the end poi point, nt, the pro proper perty ty tes testt is to be rep repeat eated ed on con condit dition ioned ed tes testt spe specim cimens ens eve every ry successive third cycle until the results of the property testing are equal to or less than the end point. In common practice, these specimens are selected from the test specimens initially put in the oven. 15.4 revised August 20, 2009
15.5 Wh 15.5 When en th the e re resu sult lts s of th the e pr prop oper erty ty te test stin ing g ar are e eq equa uall to or les less s th than an th the e en end d po poin intt , th the e se sets ts of specimens that were placed in the oven at delayed times are to be removed from the oven and tested. Their performance analysis can result in a more accurate determination of the time to reach the property end point . If the property end point is not obtained at the time that all of the original specimens have been tested, the delayed specimens can be removed from the oven at various times in the test program in order to ex exte tend nd th the e ag agin ing g ti time me.. Th This is ge gene nera rall pr proc oced edur ure e is to be fo follo llowe wed d fo forr al alll te test sts s th that at in invo volve lve th the e determination of the property end point of the test specimens. Table 15.1 summarizes this approach. A typical data sheet that can be used to record the summary of the thermal-aging testing is shown in Figure 15.1. 15.5 revised August 20, 2009
AUGUST 20, 2009
POLYMERIC MATERI AL ALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
15
15.6 Using this technique, technique, a numerical numerical value for each property is to be obtai obtained ned at the end of each cycle. It is possible to plot a curve showing the relationship between the values of each property and time at each of the 4 aging temperatures. This end point data can then be used to determine a relative thermal index. 15.6 revised August 20, 2009
15.7 At lea 15.7 least st two addition additional al dat data a poi points nts should should be obt obtain ained ed aft after er rea reachi ching ng the property property end poi point nt to confirm the end-of-life value. These data points should be as close as possible to the property end point to provide a more accurate calculation of the end-of-life value. 15.7 revised August 20, 2009
15.8 The det 15.8 determ ermina inatio tion n of the pro proper pertie ties s may req requir uire e cal calcul culati ations ons tha thatt inc includ lude e the dim dimens ension ions s of the specimens. In such cases, the dimensions of the specimens prior to oven conditioning should be recorded and used in the property calculation. Exception: For physical Exception: physical properties, properties, if the dimen dimensions sions of the specimens specimens significantly significantly change as a resul resultt of the oven conditioning, the dimensions that result in the lower physical property value should be reported and used in the property calculation. Table 15.1 Delayed Delaye d set test procedure primary properties properties Table 15.1 revised August 20, 2009 End of cycle number
Sets put in oven
Sets tested
0
B, C, D, E, F
A (unaged)
1
Ga
–
2
Ha
–
3
Ia
Bb
4, 5, 6
–
–
7
–
Cb
8, 9, 1 0
–
–
b
11
–
D
12, 13, 14
–
–
–
Eb
15
16, 17, 18
–
–
19
–
Fb
20
–
–
21
–
G
22
–
–
23
–
H
24
–
–
25
–
I
a
Sets G, H, and I are to be put in the oven one or more days later than the end of cycles 1, 2, and 3, respectively. This procedure gives time for further conditioning of sets tested resulting in a decision for removal of the delayed sets. b
Should the property end point be reached at the end of 3, 7, 11, 15, or 19 cycles, sets H and I are to be removed from the oven and tested in order to more precisely determine the property end point time. If the property end point is not reached by the end of 19 cycles, sets G, H, and I are to be tested as shown.
16
POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
AUGUST 20, 2009
NOVEMBER 29, 2000
POLYMERIC MATERI AL ALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
17
Figure 15.1 Thermal aging data summary (Destructive testing) Manufacturer____________________________________________________ Manufacturer_______________________________ ________________________________________ ___________________ Material_____________________________________ Material_________________ _________________________________________ ______________________________________ _________________ Oven Temp.____________°C; HRS/CYCLE___________ Sample Thickness_______________________________________________ Property____________________________________ Property_______________ _____________________________________ ________________
Oven Temp. Temp._____ ______° _°C; HRS/C HRS/CYCLE__ YCLE_______ _____ Sample Thickness_________________________ Property_______________________________
Averaged Test Value (Uni (U nits ts __ ____ ____ ____ ____ __))
Averaged Test Value (Units_________)
Cycle Number
Elapsed Hours
0
0
Elap El apse sed d Ho Hour urs s 0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
16 End-o End-of-Lif f-Life e 16.1 Prima Primary ry properties properties 16.1.1 When there is no information as to which of the properties (flammability, dielectric strength, strength, flexural strength, etc.) might be the first to degrade to an unacceptable value, complete testing is to be generally carried out for each property. However, where specific properties are known to degrade more rapidly, and the relative thermal index of the material is to be based on these properties, the other properties in the program are to be measured only at the end-point of the property that is tested full scale. The properties that are monitored throughout the program are to be referred to as primary properties.
18
POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
AUGUST 20, 2009
16.2 Second Secondary ary properties properties 16.2.1 The properties 16.2.1 properties that are to be measured measured only initial initially ly are to be referred referred to as secondary secondary properties properties after the property end point of the prime property occurs. If the secondary-property measurements indicate the material has passed through the end point of the secondary property , retesting – with check tests through thr oughout out agin aging g – is the then n requ required ired to est establi ablish sh the life life-te -tempe mperat rature ure rela relation tionship ships. s. Dela Delayed yed set sets s of specimens can effectively be used in this case. See Table 16.1. 16.2.1 revised August 20, 2009
Table 16.1 Delayed set test procedure – secondary properties End of cycle number
Sets put in oven
Sets tested
0
N
M (unaged)
1
O
–
2
P
–
3
Q
–
4
R
–
–
a
5, 6, 7 etc. a
All sets are to be removed from the oven and tested at the time that the earliest primary property passes through the 50–percent point as determined by the method shown in Table 15.1. If set N shows that it does not pass through the 50–percent point, the remaining sets need not be tested. If set N passes through the 50–percent point, then sets O, P, Q, and R are to be tested in turn. These sets are not aged as long as those initially put in the oven.
17 Proof Testin Testing g 17.1 In some cases, to keep the number number of specimens in the oven to a minim minimum, um, proof testing testing can be employed. In this case, the property is not to be measured in an absolute manner on aged specimens. Instead, the numerical value of the property is to be determined on unaged specimens to establish a refe re fere renc nce e va value lue.. At th the e end of ea each ch cy cycle cle du duri ring ng th the e ag aging ing-t -tes estt pr prog ogra ram m (s (see ee Ta Table ble 15 15.1 .1), ), all te test st specimens (usually 10) are to be subjected to a property stress at a level of 50 percent of the initial proper pro perty ty val value. ue. Specimens Specimens that do not have the ability ability to com comply ply wit with h thi this s pro proper perty ty str stress ess are to be removed from the test program and the length of time each specimen was in the oven is to be noted. The end-of-life is to be assumed as having occurred half way through the cycle preceding removal of the specimen from the oven. Specimens that have the ability to comply with the property stress are to be returned to the oven for further aging, and the property stress is to be repeated at the end of the following cycle. This procedure is to be continued until the property end point for all specimens is obtained. The average log life is to be determined and used to establish a relative thermal index. This type of proof testing usually is to be employed when dielectric strength is the property to be evaluated. In this case, only a single end point can be determined, and this is usually 50 percent of the initial value of the property. Exception No. 1: It has been observed from empirical data, that the logarithm of time to degrade to 50 percent of the initial property level is generally distributed normally at any given temperature. The probit method meth od of analys analysis is descr described ibed in the National Institute Institute of Stand Standards ards and Techn Technology ology Handbook Handbook 91 entitled Experimental Statistics, may be employed to estimate the log average life, provided that at least half of the samples have reached the property end point at that test temperature. Exception No. 2: For polypropylene, observation of crazing on 10 percent of the total surface area of the test specimen, rather than 50 percent retention of the initial property value, is to be used in determining the property end point time. 17.1 revised August 20, 2009
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18 Analys Analysis is and Evaluation Evaluation 18.1 After accumulat accumulating ing the data, it is necessary necessary to evalua evaluate te the insulating material material in terms of operating operating temperature and life expectancy. Also, it is important to provide a clear statement of the accuracy and uniformity of these results so that the degree of reliance can be determined. 18.2 When destructiv destructive e testing is emplo employed, yed, it is first necessary necessary to deter determine mine the aging time at which the property level decreases to the property end point at the accelerated-aging temperature. The degradation mechan mec hanism ism is usu usuall ally y a com comple plex x com combin binati ation on of ef effec fects ts due to cha chain in sci scissi ssion, on, oxi oxidat dation ion,, cha change nge in crystalinity, formation of a dense cross-linked skin, etc., and the time-temperature relationship may not accura acc uratel tely y be defi defined ned in ter terms ms of a con contin tinuou uous s sim simple ple relation relationshi ship. p. It may be pos possib sible le to gen genera erate te a simpler relationship by transforming the graph of property versus time at the different aging temperatures into discrete strength lines by use of applicable functions of time, u = f(t) or property, v = f(p). 18.2 revised August 20, 2009
18.3 If an acceptable acceptable amount of data can be obtained around around or near the property property end point , a third third-orde -orderr polynomial equation is useful to interpolate most of the data that is encountered. This method generally is not to be used for extrapolation to the property end point . The equation has the form: y = a0 + a1 t + a2 t 2 + a3 t 3 in which: y is a measure of the attribute (property level), and t is time expressed in hours. Other relationships may be employed in place of the best-fit third-order polynomial if it can be shown that a better portrayal of the data set is achieved. 18.3 revised August 20, 2009
18.4 The polynomial polynomial constants constants may be solve solved d by using the following following matrix equation: equation: Thisisgeneratedtextforfigtxt.
In the equation, n is the number of data points used in the calculations and all summations are from 1 to n. This represents four equations with four unknowns, and these can be used to solve for the coefficients a0, a1, a2, and a3 in terms of the known sums determined from the data points. Usually, at least five data points are required to establish a useful relationship. 18.5 For the purpose of illustration, illustration, consider consider the following data set:
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POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
Time Ti me (e (ela laps psed ed ho hour urs) s)
Tens Te nsile ile st stre reng ngth th (M (MPa Pa))
0
84 . 5
AUGUST 20, 2009
|
504
9 2. 6
|
1478
53 . 8
|
1915
37 . 2
}
1948
35 . 9
|
1982
39 . 9
|
2016
36 . 4
|
Data Points used in the example calculation
A judgment was made to eliminate the 0-hours, 84.5-megapascal data point from the matrix equation due to its distance away from the property end point . The matrix of 18.4 is generated in a manner that is typified by the following:
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When the simultaneous equations derived from the matrix equation are solved, the following polynomial equation is obtained to represent the data: y = 43.4075 + (1.813 x 10-1) t - (1.9084 x 10 -4) t2 + (4.936 x 10 -8) t3 At the property end point , y = 1/2 (initial property level). In the example, this corresponds to y = 42.25 mega me gapa pasc scals als.. Th The e va value lue of t whe when n y = 42. 42.25 25 me megap gapas asca cals ls ma may y be det deter ermi mined ned by it iter erat ation ion,, us using ing computer techniques. A calculated time of 1707 hours was determined using the best-fit cubic polynomial. An alternative is to express the equation coefficients as a function of percent property retention (z) versus time (t). For this alternative, the cubic equation is expressed as: z = 51.436 + (2.2576 x 10 -1) t - (2.2576 x 10-4) t2 + (5.8390 x 10 -8) t3 The value of time corresponding to z = 50 percent initial property value may be calculated as 1707 hours. 18.5 revised August 20, 2009
18.6 The life expectancy is to be considered a function of temperature. temperature. The Arrhenius equation describing the temperature dependence of the velocity coefficient of chemical reactions can be used to approximate the relationship between material life and temperature. This equation, as applied in this case, indicates that the logarithm of material life is a linear function of the reciprocal of the absolute temperature. The best fit of the slope and intercept of the straight line that relates the logarithm of material life to the reciprocal temperature is to be determined by the least-squares method of linear regression analysis. 18.6 revised November 29, 2000
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18.7 The Arrheni 18.7 Arrhenius us equation equation for rea reacti ction on rate is giv given en by k=A k=Ae e to the pow power er (−E/RT) (−E/RT) in whi which ch k is the specific reaction rate, E is the activation energy (relatively constant for a small temperature change), R is a gas constant, T is the absolute temperature, A is the frequency factor (constant), and e is 2.718284. 18.7 revised November 29, 2000
18.8 The Arrhenius Arrhenius equation can be simplified by taking natural logarithms logarithms in the following form:
letting Y = loge k, a = loge A, b = – E/R, and X = 1/T, we then have Y = a + bx. This relates the two variables Y and X in the form of a linear equation, assuming a and b are constant. 18.8 revised November 29, 2000
18.9 The evaluation evaluation of the insulation insulation is compl completed eted by the regre regression ssion analysis. analysis. This method of analysis is concerned with the study of the relationship between two or more variables. In this instance, a study is to be mad made e of the rel relati ations onship hip bet betwee ween n mat materi erial al pro proper perty ty lif life e and ope operat rating ing con condit ditions ions.. Pro Proper perty ty lif life e is denote den oted d as the dep depend endent ent var variab iable le rep repres resent ented ed by the let letter ter Y, and the ope operat rating ing con condit dition ion as the independent variable, represented by the letter X. Thus, the regression analysis becomes a study of Y (loge of specific reaction rate) as a function of X (reciprocal of operating temperature). 18.9 revised November 29, 2000
18.10 Aft 18.10 After er the Arr Arrhen henius ius equ equati ations ons for bot both h the can candid didate ate mat materi erial al and the con contro troll mat materi erial al are determined and plotted, a comparison is to be made to establish a relative thermal index of the candidate material. 18.11 The insert in Figure 18.1 illustrates illustrates the curv curve e obtained as the resul resultt of aging the material material under investigatio invest igation n at four elevated temperatures. temperatures. In the example, the prope properties rties of impac impactt stren strength, gth, tensile strength, and dielectric strength are investigated. At each temperature, the first property to reduce to 50 percent of its unaged property value is impact strength. The time to reach 50 percent at each temperature for this property is then to be used to construct the time-temperature plot shown in curve B. 18.11 revised February 16, 2006
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Figure 18.1 Plot of typical time and temperature data
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18.12 Curve A represents the plot of a control material having a relative thermal index of 100°C 100°C (212°F), (212°F), based either on previously accumulated long-time data or on the knowledge of a long, known service experience in general-use applications. This known material shows a correlation factor in this example of 60,000 hours when tested in the manner described in this program. 18.13 The time-temperat time-temperature ure plot of the mate material rial under investigation investigation crosses the 60,00 60,000-hou 0-hourr line at a temperatu temp erature re of 140°C 140°C (284°F). Therefore Therefore the material can reaso reasonably nably be expec expected ted to be as usefu usefull at a temperature of 140°C (284°F) as the control material is at 100°C (212°F). 18.14 In the absence 18.14 absence of com compar pariso ison n dat data a for a con contro troll mat materi erial, al, it mig might ht be dif diffic ficult ult to cor correl relate ate the long-time-endurance program with actual service conditions. Although there is some evidence to show that an arbitrary life of 60,000 hours under this long-time program can be assumed when determining a relative thermal index, until this correlation is more definitely established, a longer value of time is to be assumed. In place of applicable control data, an extrapolated life of 100,000 hours is to be used to assign the relative thermal index. 18.15 In considering considering the usefulness of the relative thermal thermal index in the example given in Figure 18.1, consideration is to be given to the properties that are evaluated in the program. If the properties being stressed in the end-product are also considered in arriving at the general-use thermal index, the relative thermal index resulting from this analysis is valid and can be used in the evaluation of the material in the end product. If the property being stressed in the end product is not evaluated in the long-term-aging program, the relative thermal index might not be applicable to the use of the material in that particular application. 18.16 In considering considering the example shown in Figur Figure e 18.1, it is possible that more than one temperature temperature rating ratin g can result from analys analysis is of the data accum accumulated ulated during the long-t long-time ime investigation. investigation. In the example described in 18.11 the most critical property being investigated is impact strength and the general-use relative relat ive therm thermal al index of 140°C (284°F) is applic applicable able to all applic application ations s involv involving ing all of the prope properties rties investigated, including impact strength. However, there can be applications of this material in which impact stre st reng ngth th is no nott a cr crit itic ical al pr prop oper erty ty,, su such ch as in an ap appli plica cati tion on in wh whic ich h th the e ma mate teri rial al is sh shiel ielde ded d fr from om mechanical abuse as is the case for some insulating materials, terminal boards, wire connectors, etc. In that event, a time-temperature plot could be made for the unknown material considering all properties except impact strength. In such an example, it might be possible to have a relative thermal index of, say 155°C (311°F), (311°F), for applications in which impact strength is not a critical property and 140°C 140°C (284°F) (284°F) for applications in which impact strength is required. 18.17 Car 18.17 Care e is to be exe exerci rcised sed in the use of any gen genera eral-u l-use se rel relati ative ve the therma rmall ind index ex ach achiev ieved ed by the method of analysis described in this standard. If it is felt that the end-product application of the material involves unusual service conditions, the acceptability of the material at the relative thermal index is judged by this method is to be reviewed. If service conditions associated with an end-product application are less severe than those considered in arriving at the relative thermal index, higher operating temperatures may be acceptable. 19 Relat Related ed Material – Coverage of Variations in Material Composition Composition 19.1 Gener General al 19.1.1 Comme 19.1.1 Commercial rcially ly availa available ble brands of insulating materials materials are usually obtainable in diff different erent molecular molecular weights and colors, and with differing types and quantities of fillers and additives. A separate analysis of each of these variations is not necessary to an evaluation in a thermal-endurance program.
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19.1.2 The least favor 19.1.2 favorable able performance performance of the unfilled and maxim maximum-le um-level vel filled or reinforced reinforced mater material ial shallll be con sha consid sidere ered d rep repres resent entati ative ve of int interm ermedi ediate ate lev levels els of fille fillerr or rei reinfo nforce rcemen mentt wit withou houtt add additi itiona onall testing. 19.2 Therm Thermoplast oplastic ic materials 19.2.1 Therm 19.2.1 Thermoplas oplastic tic materials materials that are related to others in the program can, in accordance accordance with 19.2.2.3 19.2.2.3 – 19.2.6, and Table 8.1 and Table 8.2 of UL 746A, be evaluated in an abbreviated test program. This program applies specifically to families of thermoplastic materials in which each of the related materials is intended to have properties that differ slightly from the basic material and generally is assigned a different compound designation. 19.2.1 revised April 17, 2009
Table 19.1 Test consideration for related materials based upon variation in material composition Table 19.1 deleted April 17, 2009
19.2.2 19.2. 2 Delete Deleted d May 9, 1997. 19.2.2.1 19.2. 2.1 Delet Deleted ed April 17, 2009 19.2.2.2 19.2. 2.2 Delete Deleted d April 17, 2009 19.2.2.3 In cases where the limits 19.2.2.3 limits in Table 8.1 of UL 746A are excee exceeded, ded, testing testing will include one or two temperature aging (UL 746B) using the unaltered basic material as the control reference. Both the impact and non non-im -impac pactt mec mechan hanica icall pro proper pertie ties s tes tested ted in the nominal nominal 3 mm thi thickn ckness ess can be con conside sidered red representative of other properties and thicknesses, however, if a lowering of the non-impact mechanical index is indicated, then the electrical index not tested will be automatically lowered by the same amount and materials may need to be checked after additional aging for retention of flame retardancy. 19.2.2.3 revised April 17, 2009
19.2.2.4 Refer 19.2.2.4 Reference ence materials materials to be considered considered as the unaltered unaltered basic material for application application of the limits in Table 8.1 of UL 746A, and for use as a control in any required tests, shall be a material that has actually been subjected to thermal aging tests and not a material with an assigned temperature index based solely on a previous application of this analysis. 19.2.2.4 revised April 17, 2009
19.2.2.5 19.2.2 .5 If testing testing of a rel relate ated d mat materi erial al is not indicate indicated d in Table 8.1 of UL 746 746A, A, the mat materi erial al can be assigned the same temperature rating as the original material. 19.2.2.5 revised April 17, 2009
19.2.3 A comparison 19.2.3 comparison of the results of aging at one temperature temperature (neither (neither the highest nor the lowest used in the investigation of the basic material) with the life-line (Arrhenius curve) of the basic material is to be conducted, assuming parallel performance and extrapolated to the life value corresponding to the relative thermal index of the base material. If the difference between the extrapolated life of both materials is within 5°C (9°F), (9°F), then the related material is to be assigned the same relative thermal index as that determined for the basic material. material. If the difference difference between the extr extrapolat apolated ed lives of both mater materials ials is not within 5°C (9°F), the rel relate ated d mat materi erial al can cannot not be ass assigne igned d a rel relativ ative e the therma rmall inde index x unle unless ss the addi addition tional al agin aging g described in 19.2.4 is conducted. See 19.2.7 for an illustrative example.
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19.2.4 If comparison 19.2.4 comparison of the results of aging at the two mid-temperatur mid-temperatures, es, used in the investigation investigation on the basic material material but displa displaced ced so as to have the best fit with the two new points, extrapolates extrapolates to within 5°C 5°C (9°F) of the relative relative the therm rmal al ind index ex of bas basic ic mat materi erial, al, the related related mat materi erial al is to be ass assign igned ed the sam same e relative thermal index as that determined for the basic material. In the event that the extrapolation is to a temperature in excess of 5°C (9°F) (9°F) of the basic material’s relative thermal index, the related material is to be assigned a relative thermal index at the corresponding reduced value. See 19.2.8 for an illustrative example. 19.2.5 A relat 19.2.5 related ed material is to be assign assigned ed a temp temperatu erature re rating not more than 10°C 10°C (18°F) above the rating of the basic material based on extrapolation of an Arrhenius curve having the same slope as the original curve but displaced so as to have the best fit with the results of aging of the related material at the two mid-temperatures of the investigated basic material. 19.2.5 revised May 9, 1997
19.2.6 A relat 19.2.6 related ed material is to be assign assigned ed a temp temperatu erature re rating more than 10°C (18°F) above the rating of the basic material only on the basis of an aging program at four temperatures. 19.2.6 revised May 9, 1997
19.2.7 The following 19.2.7 following data on a base material compared compared to data obtained obtained on a related material material aged and tested under the same procedure and condition is intended as an illustration: Material life Time (hours) to reach the property end point Temperature, °C
Base material
Related material
2 00
1200
–
1 90
1824
1150
1 80
3288
–
1 70
5232
–
Using the pro Using proced cedure ure in Ana Analys lysis is and Eva Evalua luatio tion, n, Sec Sectio tion n 18, lin linear ear reg regres ressio sion n ana analys lysis is on the bas base e material’s mate rial’s data resul results ts in the relat relationshi ionship: p:
A relat relative ive thermal index of 125°C 125°C is assig assigned ned to the base mate material, rial, which corresponds corresponds to a 77,17 77,179 9 hour correlation time (life). It is to be assumed that the slope of the related material is identical to the slope of the base material, and that the equations differ only in the value of the ordinate intercept. The equation for the related material can be found by substituting the known data point as follows:
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26A
thus A = -6.7838 Hence, the relationship between time and temperature for the related material is given by:
At the base material correlation time, the related material’s relative thermal index is given by:
which can be calcul calculated ated as 118.8 118.8° °C. This value is not within the 5°C 5°C diff different erential ial indicated in 19.2. 19.2.3 3 and the related material is not eligible for a relative thermal index unless additional tests are conducted. 19.2.7 revised August 20, 2009
19.2.8 Continuing 19.2.8 Continuing the examp example le in 19.2. 19.2.7, 7, assume assume that the manuf manufactur acturer er gener generates ates additional additional data at 180°C (356°F) that resul results ts in a mater material ial life of 2200 hours – that is, T1 = 463.16K (190°C) (190°C) Life1 = 1150 hours T2 = 453.16K (180°C) (180°C) Life2 = 2200 hours This data can be expressed as a single arithmetic mean value as:
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The equation for the related material is to be found by substituting the mean data as follows:
or A1 = –6.7515 Hence, the between time and temperature relationship for the related material is given by:
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At the base material correlation time, the related material’s relative thermal index is given by:
which can be calcu calculated lated as 118.6 118.6° °C. Using the procedures procedures in 19.2. 19.2.4, 4, the mater material ial would be assign assigned ed a relative thermal index of 115°C. 19.2.8 revised November 29, 2000
19.3 Therm Thermosett osetting ing molded materials 19.3.1 Therm 19.3.1 Thermosett osetting ing materials that are relat related ed to other materials materials evaluated under the aging program program in the same manner and within the same limits as thermoplastic materials as described in 19.2.1 – 19.2.6 and Table 8.1 of UL 746A are also eligible for the abbreviated test program. In addition, because periodic variations are often necessary in the formulation of thermosetting materials in order to adapt to variable sources of supply and to adjust for variable molding conditions, it is acceptable if the limits specified in Table 8.1 of UL 746A are exceeded, provided that the same numerical compound designation is used and the conditions in 19.3.2 and 19.3.3 are met. 19.3.1 revised April 17, 2009
19.3.2 An abbreviated 19.3.2 abbreviated heat-aging heat-aging test is to be condu conducted cted in accor accordance dance with 19.2.3 or 19.2. 19.2.4. 4. Property, Property, time, temperature, and percent retention of the property are to be selected based on information obtained in the long-time thermal-aging program. 19.3.3 Analyt 19.3.3 Analytical ical measurement measurements s are to be used to ascertain that the materials materials have essentially essentially the same formulatio form ulation n ingre ingredient dients, s, prop proportio ortions, ns, and prope properties rties.. Infr Infra-re a-red d analy analysis sis and Ther Thermogr mogravime avimetry try determ det ermina inatio tions ns are to be inc includ luded. ed. Dif Differ ferent ential ial Sca Scanni nning ng Cal Calori orimet metry ry may als also o be inc includ luded ed whe where re applicable.
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20 Aging, Specimen, Specimen, and Check-Test Schedules Schedules 20.1 Gener General al 20.1.1 Tables 20.1 – 20.3 are for use in assis 20.1.1 assisting ting manufacture manufacturers rs in form formulatin ulating g a long-t long-time ime thermal-agin thermal-aging g program. 20.1.2 The schedules shown in Table 20.1 – 20.3 are examples for demonstration demonstration purposes only. Specific aging temperatures, tests, specimen sizes, etc. are to be applicable to the specific polymer and end use. In most cases, five specimens per measurement are to be employed but, in some cases, ten specimens are needed. 20.1.3 The number of speci 20.1.3 specimens mens tabulated tabulated is based on the presu presumptio mption n of attaining the property property end point within the number of aging cycles indicated in the delayed-set schedules. 20.1.3 revised August 20, 2009
20.1.4 Descr 20.1.4 Described ibed in 20.2. 20.2.1 1 – 20.3. 20.3.13, 13, are particular particular test progr programs ams for materials or procedures procedures of unusu unusual al nature that do not follow the general procedures shown in Tables 20.1 – 20.3. 20.2 Polypr Polypropylen opylene e 20.2.1 For polypropylene, 20.2.1 polypropylene, it is obser observed ved that the occur occurrence rence of visible crazing indicates the severe and sudden loss of material properties. The thermal-aging procedure described in Tables 20.1 – 20.3 may be considerably reduced since surface crazing can be used as a preliminary indication of material-property loss. The quantity and sizes of samples required for a polypropylene thermal-aging program are described in Table 20.4. 20.2.2 The 20.2.2 Therma rmall agi aging ng is to be con conduc ducted ted at fou fourr ove oven n tem temper peratu atures res as des descri cribed bed in Tab Table le 12. 12.1, 1, for exampl exa mple e 160 160,, 150 150,, 140 and 130 130° °C (32 (320, 0, 302 302,, 284 284,, and 266°F). Samples Samples are to be age aged d at all fou fourr temperatures for evaluation of the primary properties of tensile impact and tensile strength. Samples are to be aged at either of the two intermediate test temperatures for evaluation of the secondary properties of flammability and dielectric strength. 20.2.3 Ove 20.2.3 Ovens ns at each tem temper peratu ature re are to be loa loaded ded with one set of test sam samples ples initiall initially y (se (sett A). The second set of samples (set B) is to be placed in each oven at a later time than the initial batch (set A) in accordance accor dance with Table 20.5. 20.2.4 Usi 20.2.4 Using ng the pro proof of tes testin ting g met method hod des descri cribed bed in 17. 17.1, 1, for eac each h dif differ ferent ent sam sample ple con configu figurat ration ion,, thickness and test temperature, the property end point is to be determined by noting the time at which each initial set of test samples (set A) shows crazing on 10 percent of the total surface area of each specimen. When this crazing occurs, the oven time is to be recorded and all crazed samples are to be removed from the oven. When all the initial samples (set A) have crazed, the delayed samples (set B) and secondary-property samples are to be removed from the oven. Prior to property testing, of the delayed (set B) and secondary-property samples, the samples are to be conditioned in accordance with Table 20.1. 20.2.4 revised August 20, 2009
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20.2.5 The proof testing 20.2.5 testing method method describe described d in Exc Except eption ion No. 2 of 17.1 is to be use used d to determin determine e the average log life for the 10 initial test samples (set A) for each different configuration and test temperature. The second set of tensile strength, tensile impact and dielectric strength samples (set B) shall retain at least 50 percent of the initial property value and the flammability classification shall not change. 20.3 Coatin Coating g powders powders 20.3.1 The testing of coating powders 20.3.1 powders to deter determine mine a relat relative ive thermal thermal index for use as groun ground d insulation in mot motors ors,, tra transf nsform ormers ers,, bus bar bars, s, and the like like,, ope operat rating ing at hig higher her tha than n Cla Class ss 105 tem temper peratu atures res,, is covered in 20.3.2 – 20.3.13. 20.3.2 Thi 20.3.2 This s sub subsec sectio tion n und under er coa coatin ting g pow powder ders s is to be con consid sidere ered d onl only y as a guid guide e for establis establishin hing g a testing program, as specific details must be worked out for each material and end-use application. The tests test s are to inclu include de cons considera ideration tion of all varia variations tions in chem chemical ical composition, composition, color percentage percentage mix, molecular weight, etc. 20.3.3 The end-product evaluation is to result result in the final judgment concerning the test test performance (such as for insulation), insulation), const constructi ructional onal requirements requirements (such as thickn thickness), ess), and other considerations considerations,, such as: a) Norma Normall and abnormal tests. tests. b) Addit Additional ional abnormal abnormal tests necessitate necessitated d by the specifi specific c polym polymeric eric material. material. c) Eff Effect ect of adjace adjacent nt insulation insulation on performance performance at point points s of material contact. contact. d) The general maximum maximum voltage rating rating under this program is 600 volts volts.. If highe higherr voltages are a consideration, additional testing is necessary – higher dielectric-strength potentials, resistance to parti partial al discha discharge, rge, etc.
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Table 20.1 Conditioning before property measurement (Example) Table 20.1 revised September 29, 1998 Property Tensile or flexural strength
Min. 40 h exposure to 50 ± 5 perce percent nt relat relative ive humidity at 23.0 ±3.0° 3.0°C C (73.4 ( 73.4 ± 5.4°F)
Tensile, Izod, or Charpy impact Dielectric strengtha
Min. 40 h exposure to 50 ± 5 perce percent nt relat relative ive humidity at 23.0 ±3.0° 3.0°C C (73.4 ( 73.4 ± 5.4°F)
Flam Fl amma mabi bili lity ty (m (mat ater eria iall ra rate ted d V– V–2 2 or be bett tter er))
Cool Co oled ed in de desi sicc ccat ator ors s a mi mini nimu mum m of 4 ho hour urs s af afte terr ov oven en exposure
aThe surrounding surrounding medium for the dielectric dielectric stren strength gth test shou should ld be air, or oil using shrouded shrouded electrodes electrodes in acco accordanc rdance e with ASTM D149.
Table 20.2 Typicall aging schedule Typica (Example)
Material
Candidate (proposed)
Control (known)
Thickness mm
Cycle periods, daysa
Aging temperature, °C A
B
C
D
A
B
C
D
3. 2
130
14 0
15 0
160
28
14
7
3
1. 6
–
1 40
15 0
–
–
14
7
–
0. 8
–
1 40
15 0
–
–
14
7
–
3. 2
130
14 0
15 0
160
28
14
7
3
aCycle period subject to change as more data becomes available.
JULY 21, 1997
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31
Table 20.3 Number of specimens required for thermal aging (example) Table 20.3 revised July 21, 1997 Test
Specimens Thickness mm
Number for all temperatures
Number for UL referee testb
Total
Test material
Prop Pr oper erty ty
Meth Me thod od
ASTM
IS O
Number per set
Number for initial tests
Candidate
Tensile or
UL 746A
3. 2
4.0
5
10
220
60
290
flexural
1. 6
2.0
5
10
110
–
120
strength
0. 8
1.0
5
10
11 0
–
120
(proposed)
Tensile,
3. 2
4.0
5
10
22 0
60
290
Izod, or
1. 6
2.0
5
10
1 10
–
120
Charpy impact
0. 8
1. 0
5
10
11 0
–
12 0
Dielectric
UL 746A
UL 746A
0. 8
5
10
2 20
–
230
UL 94
MTa
20
20
1 00
20
140 14
UL 746A
3. 2
4.0
5
10
22 0
60
290
UL 746A
3. 2
4.0
5
10
22 0
60
290
UL 746A
0. 8
5
10
2 20
–
230
strength Flammability (materials rated V–2 or better) Control (kno (k nown wn))
Tensile or flexu fle xurral strength Tensile, Izod, or Charpy impact Dielectric
strength aMT represents the minimum thickness evaluated, usually 0.8 mm. bThese specimens are only required if a UL referee test is considered necessary.
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Table 20.4 Number of specimens required for a typical polypropylene thermal aging program Table 20.4 revised July 21, 1997 Test
Specimens
IS O
Number per set
Number for initial tests
Number for all temperatures (set (s ets s A an and d B)
Tota To tall
3.2
4.0
10
10
80
90
3.2
4. 0
10
10
80
90
1. 6
2. 0
10
10
40
50
2. 0
5
10
20
30
5
10
20
30
Thickness mm Test material
Prop Pr oper ertty
Mettho Me hod d
ASTM
Candidate (proposed)
Tensile strength
UL 746A
Tensile or Charpy impact
UL 746A
Control (known)
Dielectric strength
UL 746A
1 .6 1.
Flammability (materials rated V-2 or better)
UL 94
MTa
Tensile strength
UL 746A
3.2
4. 0
10
10
80
90
Tensile or Charpy impact
UL 746A
3. 2
4. 0
10
10
80
90
aMT represents the minimum thickness evaluated.
Table 20.5 Delay time for insertion of verification samples in polypropylene aging programs
Aging temperat temperature ure °C (°F) (°F)
Delay time to insert second sample set (Set B) in oven after start of progr program, am, days
160 (320)
3
150 (302)
7
140 (284)
14
130 (266)
28
JULY 21, 1997
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33
20.3.4 20.3. 4 The te test st spe specim cimens ens to be use used d fo forr mo moto torr or tr trans ansfo form rmer er gro ground und ins insula ulatio tion n ar are e to be st steel eel U-channels of the shape and size shown in Figure 20.1. The scale on the interior surface of the specimen is to be removed by means of sandblasting or an acid rinse followed by a water rinse, an alkaline rinse, and a final water rinse. Each specimen is to be machined as indicated in Figure 20.1 to a 32-microinch (810-micrometer) finish. The specimens are then to be coated with powder in the thickness specified by the manufacturer using a typical process. The powder is then to be cured as advised by the manufacturer. One end of the specimen is to be left uncoated for attaching the specimen to a vibration machine and also for making an electrical connection during the dielectric-strength tests. Prior to aging, all specimens are to be subjected to a screening test in order to remove defective units. Exception: Excep tion: Groun Ground d tool-steel tool-steel bits as illust illustrated rated in Figure 20.2 may be employed in place of U-channels. U-channels. Table 20.6 Number of specimens required for thermal aging (film
≤ 0.010
inch)
Table 20.6 revised July 21, 1997 Test Test material
Property
Candidate (proposed)
Tensile strength Dielectric strength Flammability (materials rated VTM-2 or V-2 or better)
Control (known)
Specimens Thickness mm
Number per set
Number for initial tests
Number for all temperatures
Number for UL referee testb
Total
ASTM D-882
0.127
5
10
160
60
2 30
5
10
80
–
90
ASTM D-1830
MTa MTa
5
10
160
–
17 0
MTa
20
20
1 00
20
1 40
Method
UL 94
Tensile strength
ASTM D-882
0. 1 27
5
10
16 0
60
2 30
Dielectric strength
ASTM D-1830
MTa
5
10
16 0
–
170
aMT represents the minimum thickness evaluated, usually 0.8 mm. bThese specimens are only required if a UL referee test is considered necessary.
34
POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
AUGUST 28, 1996
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Figure 20.1 Specimen dimensions All dimensions in mm (inch)
Material: American Iron and Steel Institute Type C1020 steel, U-channel, standard 19.05 by 7.94 by 3.18 mm (3/4 by 5/16 by 1/8 inch) bar stock. Modified as follows: 1) The outer surfaces surfaces and the end of the specimen specimen that is to be coated are to be machined machined to a 810-micrometer 810-micrometer (32-microi (32-microinch) nch) finish. 2) The finished finished dimensions dimensions are not critic critical. al. 3) Burr Burrs s are to be remov removed ed without rounding rounding the edges.
20.3.5 The test specimens 20.3.5 specimens to be used for evalua evaluating ting integral integral bus-bar insulation insulation systems are to be copper and/or aluminum specimens of the size and shape shown in Figure 20.2. 20.3.6 To det 20.3.6 determ ermine ine an init initial ial die dielec lectri tric-s c-stre trengt ngth h lev level, el, spe specim cimens ens are to be sel select ected ed at ran random dom and subjected to a voltage breakdown test. To prevent flashover, the unaged specimens may need to be provided in a length greater than 127 mm (5 inch). One electrode of the tester is to be connected to the uncoated end of the specimen and approximately 50.8 mm (2 inch) of the coated end of the specimen are to be imm immers ersed ed int into o a 1010-per percen cent-s t-salt alt-wa -water ter sol soluti ution, on, whi which ch is the oth other er ele electr ctrode ode of the tes tester ter.. The voltage from the tester is to be increased at a rate of approximately 500 volts per second until breakdown occurs. The average breakdown value of the ten specimens is to be recorded as the initial breakdown voltage of the material. At least ten specimens are to be placed in each of four ovens, the temperatures of which are to be determined by the manufacturer. The highest temperature is to result in a life of at least 500 hours while the lowest temperature is to result in a life of at least 5,000 hours.
AUGUST 20, 2009
POLYMERIC MATERI AL ALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
35
Thisisgeneratedtextforfigtxt.
Figure 20.2 Alternate tool-steel and bus-bar test specimens All dimensions in mm (inch)
NOTE – Substrate material is to be ground square to within 0.01 mm (0.001 inch) with sharp (no measurable radius) edges. 810-micrometer (32-microinch) finish on four long sides.
20.3.7 To pro 20.3.7 provid vide e app approx roxima imatel tely y equ equal al exposu exposures res to the oth other er con condit dition ioning ings s and to mor more e acc accura uratel tely y dete de term rmin ine e th the e pr prop oper erty ty en end d po point int , th the e he heat at agin aging g ti time me pe perr cy cycl cle e is to be le less ss fo forr th the e hi high gher er ag agin ing g temperatures– for example: a) Highes Highestt oven temperatur temperature e – 1 or 2 days per cycle b) Next oven temperat temperature ure – 2 to 4 days per cycle cycle c) Next oven temperat temperature ure – 4 to 14 days per cycle d) Lowes Lowestt oven temperature temperature – 3 to 7 weeks per cycle 20.3.7 revised August 20, 2009
20.3.8 20.3 .8 At th the e en end d of eac each h ex expo posu sure re in th the e ov oven en,, all sample samples s ar are e to co cool ol to ro room om te temp mper erat atur ure e fo forr approximately 1 hour. All samples are then to be subjected to a cold shock for 1 hour. If the coating resin is intended for outdoor applications, the temperature of the cold box is to be minus 20.0 ±2.0° 2.0°C C (minus 4.0 ±3.6°F). If the coating resin is inten intended ded for indoor applications applications only, the tempe temperatu rature re of the cold box is to be 0.0 ±2.0°C (32.0 ±3.6°F). 20.3.9 Followi 20.3.9 Following ng the cold shock shock,, all sampl samples es are to stand for 1 hour at room temperatu temperature. re. All samples are then to be subjected to a vibration test consisting of 10,000 cycles of vibration at an acceleration of 7 G’s. If the motion of the specimen during the vibration test is simple harmonic, the maximum peak-to-peak deflection is to be 0.97 mm (0.038 inch), if the frequency of vibration is 60 hertz. The direction of the vibration is to be parallel to the shortest dimension of the specimen and orthogonal to the largest flat surface of the specimen.
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POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
AUGUST 20, 2009
20.3.10 Followi 20.3.10 Following ng the vibration vibration test, all samples are to be subjec subjected ted to a humid humidity ity test for a period of 24 hours at 25 – 30°C (77 – 86°F) with the relative humidity humidity adjust adjusted ed to 95 – 100 percent. 20.3.11 Withi 20.3.11 Within n 1 hour after the humidity humidity test, all specim specimens ens are to be subjected to a proof voltage voltage test. The applied voltage is to be raised from zero at a rate of approximately 500 volts per second until the voltage reaches a value equal to 50 percent of the initial breakdown voltage of the material. This value of the voltage is to be maintained for 5 seconds, and the voltage is then to be removed from the specimen. Specimens that do not break down during this test are to be returned to the oven for further testing. 20.3.12 The aging-test 20.3.12 aging-test program is to be conti continued nued until all specim specimens ens have exhibited breakdown. breakdown. The time to breakdown for each specimen is to be recorded. 20.3.13 20.3. 13 The data is to be evalua evaluated ted by the proof-test proof-testing ing method described described in Proof Testing, Testing, Section 17. 20A Fixed Time Time Sampling Sampling Method 20A.1 Gener General al 20A.1.1 20A.1. 1 As an alt altern ernate ate to the Fixed Temperat Temperature ure Method Method in Sec Sectio tions ns 12 – 20, the sam samplin pling g met method hod descr de scrib ibed ed in th this is sec secti tion on ma may y be us used ed to co condu nduct ct th the e lon longg-te term rm hea heatt ag aging ing pr prog ogra ram. m. The pr prim imar ary y difference between the methods is in the sampling technique employed. Since both methods rely upon a data analysis of the degradation degradation of sampl samples es at variou various s temp temperatu eratures res and using specific time intervals, intervals, the results of the tests would be expected to be similar regardless of which of the two methods is selected. 20A.1.1 added February 22, 2000
20A.1.2 Section 13, Selection of Control Material, and Section 14, Specimens, are applicable to the Fixed Time sampling method. 20A.1.2 added February 22, 2000
20A.1.3 This sampling method was develo 20A.1.3 developed ped with the objective objective of completing completing most evaluations evaluations within approximately 5,000 hours of testing. This is accomplished through a more intensive selection of aging temper tem peratu atures res in the early por portio tion n of the program program (th (the e scr screen eening ing pro proced cedure ure)) and by usi using ng the aging temperatures as the dependent variables while aging interval are the controlled variable. 20A.1.3 added February 22, 2000
20A.1.4 To determine the performance 20A.1.4 performance characterist characteristics ics of the material, material, a series of specimens is to be tested for property retention levels following fixed time frame aging intervals. The aging temperatures for the Fixed Time Frame Method are normally not established until after the screening procedure described in Section 20A.2 is completed. 20A.1.4 added February 22, 2000
AUGUST 20, 2009
POLYMERIC MATERI AL ALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
36A
20A.2 Scree Screening ning Procedure Procedure 20A.2.1 As a gener 20A.2.1 general al guideline in select selecting ing the tempe temperatu ratures res to be used for conditioning conditioning of the ther thermal mal aging specimens, select four or more aging temperatures starting approximately 40°C 40°C above the expected RTI of the candidate material. Alternatively, temperatures may be chosen based on prior experience. The aging temperature temperatures s select selected ed shall be at increments increments of at least 10°C. The contr control ol mate material rial should also be aged in the screening procedure. The temperatures selected for the control and the candidate materials should cover the same range but due to differences, melt temperatures, or other circumstances the range of aging temperatures for the control and candidate may not be the same but should overlap. 20A.2.1 added February 22, 2000
20A.2.2 The selected screening 20A.2.2 screening temperatures temperatures should span the prope property rty end point value; at least one measured value being above and one measured value being below the property end point value. If the initial temperatures selected do not result in at least one value above and one below the property end point poi nt , add additio itional nal agi aging ng tem temper peratu atures res shall be add added ed to the screenin screening g pro progra gram. m. A min minimu imum m of fou fourr temperatures shall be included in the screening so as to provide at least one value above and one below the property end point value (using the calculations presented later in this section). 20A.2.2 revised August 20, 2009
20A.2.3 A set of specim 20A.2.3 specimens ens shall be placed into the aging oven for each property to be evaluated. evaluated. The preferred aging time for the Screening Test is 552 hours; however, other lengths of aging may be used. At the completion of the selected aging interval, all of the specimens are to be pulled, conditioned and tested for retention of properties. 20A.2.3 added February 22, 2000
20A.2.4 Calculate the average percentage of retention of properties for for each set of specimens as follows. Using the initial (unaged) measurement for each property, express the individual average property values as a percent of the initial value. This calculation will provide four sets of temperature-percent retention values. Using the four sequential/percent retention values meeting the conditions from paragraph 20A.2.2, calculate the temperature at which the property end point value can be assigned. The property end point values shall be based on a linear regression through the set of temperature-percent retention values. 20A.2.4 revised August 20, 2009
20A.2.5 The calculated 20A.2.5 calculated property property end point value is the temperature temperature that is assigned to the fixed time of the aging interval. This time-temperature value is one of the fixed coordinates needed for the analysis and calcul cal culati ation on of the the therma rmall inde index x val value ue in acc accord ordanc ance e wit with h Sec Sectio tion n 18. Thi This s tim time-t e-temp empera eratur ture e can be designed as ttime interval. 20A.2.5 revised August 20, 2009
20A.2.6 If the result 20A.2.6 results s of the screening screening test are not consis consistent tent with a simple (linear) (linear) thermal degradation degradation,, such as with polypropylene materials, aging temperatures should instead be selected based on a study of the physi physical cal chara character cteristics istics,, or test history of mater materials ials with similar chemi chemical cal comp compositio osition. n. 20A.2.6 added February 22, 2000
36B
POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
AUGUST 20, 2009
20A.3 Remain Remainder der of Fixed Time Sampling Method Method 20A.3.1 Based on usable results 20A.3.1 results of the scree screening ning procedure, procedure, additional additional Fixed Time sampling sampling meth method od intervals can then be selected and the remainder of the sampling (aging program) begun. The preferred additional aging intervals are 1,008 hours, 2,016 hours, and 5,040 hours. Using the pattern in the results of the screening procedure, select four, or more, aging temperatures for the two additional aging intervals. The aging tempe temperatu ratures res shall be at incre increments ments of at least 10°C. 20A.3.1 revised November 29, 2000
20A.3.2 Following the test format described described in the screening procedure, use the the four aging evenly-spaced temperatures for each aging interval that have at least one measured value above and one below the proper pro perty ty end poi point nt val value. ue. Cal Calcul culate ate the temperat temperature ure at whi which ch the pro proper perty ty end poi point nt val values ues can be assigned. Designate each value as ttime interval(preferred t 1008, t2016, and t5040). 20A.3.2 revised August 20, 2009
20A.3.3 Analys 20A.3.3 Analysis is of the data obtained (at the 1,008, 2,016, and 5,040 hour points) points) using the Fixed Time sampling method shall be as described in Section 18. 20A.3.3 revised November 29, 2000
RELATIVE THERMAL INDEX CLASS 21 Assign Assignment ment of Temperature Temperature Classifications Classifications 21.1 The relative relative thermal index of insula insulation tion materials materials is to be assign assigned ed in accor accordance dance with the following standard temperature classifications: a) 5°C (9°F) (9°F) increments in crements up to 130° 130°C C (266° (266 °F). b) 10° 10°C C (18° (18°F) F) increme increments nts from 130° 130°C C (266° ( 266°F) F) through 180° 180°C C (356° ( 356°F). F). Exception: Includes 155°C (311°F). c) 20° 20°C C (36° (3 6°F) increment i ncrements s over ov er 180° 18 0°C C (356° (3 56°F). F). Exception: Includes 190°C 190°C (374°F) (374°F) and 210°C (410°F) (410°F) providing that the temperature differential of the test ovens are within 3.0°C 3.0°C (5.4°F) (5.4°F) of the nominal oven aging temperature.
NOVEMBER 28, 2001
POLYMERIC MATERI AL ALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
37
MARKING 22 Gen Genera erall 22.1 Mate Material rial containers containers shall be marked with the follow following: ing: a) The manufacturer’s or private labeler’s name or identifying symbol. b) A distin distinctive ctive material material design designation ation.. 22.2 If a manufacturer produces the material material at more than one factory, each material material container shall have a distinctive marking to identify it as the product of a particular factory.
38
POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
No Text on This Page
AUGUST 28, 1996
AUGUST 28, 1996
POLYMERIC MATERI AL ALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
SA1
SUPPLEMENT SA - FOLLOW-UP INSPECTION INSTRUCTIONS INTRODUCTION SA1 Sco Scope pe SA1.1 This Supplement Supplement descr describes ibes the manuf manufactur acturer’s er’s production production progr program am necessary to verif verify y that the product continues to be in compliance with the requirements in this Standard. SA1.2 This Supplement Supplement also descr describes ibes the dutie duties s and responsibilitie responsibilities s of the field repr represent esentative ative of the certification organization. SA1.3 Recogn Recognizing izing that manufacturers manufacturers are required to have quality assurance assurance systems in place for the control of their production processes and products, this Supplement only covers the sampling inspections, tests, test s, and other meas measures ures taken by the manufacturer manufacturer and consi considered dered to be the minim minimum um requirements requirements of the certification organization. Such inspections, tests, and measures are supplemented by the certification organi org anizat zation ion as an aud audit it of the mea means ns tha thatt the man manufa ufactu cturer rer exe exerci rcises ses to det determ ermine ine con confor forman mance ce of products with the certification organization’s requirements. SA1.4 The cer SA1.4 certific tificati ation on orga organiza nizatio tion n shal shalll hav have e addi addition tional al auth authori ority ty spe specifie cified d in lega legally lly bind binding ing agreem agr eement ents, s, sig signed ned by bot both h the cer certifi tificat cation ion org organiz anizati ation on and man manufa ufactu cturer rer,, to con contro troll the use and application of the certification organization’s registered mark(s) for product, packaging, advertising, and associated literature. The legal agreements shall cover the control methods to be used by the certification organiza orga nization tion and the manu manufact facturer urer’s ’s opti options ons for appe appeal. al. Any addi additiona tionall inspe inspection ctions, s, test tests, s, or othe otherr measures deemed necessary by the certification organization but to be taken by the manufacturer are to be applied in order to control the use and application of the certification organization’s registered Mark(s). SA2 Glossa Glossary ry SA2.1 For the purpo purposes ses of this Supplement, Supplement, the following definitions definitions apply. SA2.2 CERTIF CERTIFICATI ICATION ON ORGANI ORGANIZATIO ZATION N – A third party organization organization independent independent of the manuf manufactur acturer er who, under a legally binding contract contract with the manuf manufactur acturer, er, evaluates evaluates a produ product ct for compl compliance iance with requiremen requi rements ts specified in the Standard, Standard, and who maint maintains ains periodic inspection inspection of produ production ction of these products to verify compliance with the specifications in the Procedure and this Supplement. SA2.3 FIELD REPRESENTATIVE REPRESENTATIVE – An autho authorized rized representat representative ive of the certification certification organization organization who makes periodic unannounced visits to the manufacturer’s facilities for purposes of conducting inspections and monitoring the manufacturer’s production program. SA2.4 INSPECTION REPORT – The report generated by the field representative summarizing summarizing the results of the inspection visit. SA2.5 MAN SA2.5 MANUFAC UFACTUR TURER ER – The aut author horize ized d par party ty who mai mainta ntains ins and ope operat rates es the fac facilit ilities ies whe where re a Recogn Rec ognize ized d Com Compon ponent ent is pro produc duced ed or sto stored red and whe where re the pro produc ductt is ins inspec pected ted and and/or /or tes tested ted as described in this Supplement. SA2.6 PROCEDU PROCEDURE RE – The document issued issued by the cert certificati ification on organization, organization, upon determination determination that a product is eligible for Recognition, for use by the manufacturer and the field representative. The document contains cont ains requ requirem irements ents and othe otherr prov provision isions s and condi condition tions s rega regarding rding the Recog Recognize nized d produ product ct and provides the authorization for the manufacturer to use the Recognition Marking on products fulfilling these requirements.
SA2
POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
AUGUST 28, 1996
SA2.7 RECOGNI RECOGNIZED ZED COMPONENT – A part or subassembly subassembly intended for use in other equipment equipment and that has been investigated for certain construction or performance, or both, characteristics. A Recognized Component is incomplete in construction features or is restricted in performance capabilities so as not to warran war rantt its acc accept eptabi abilit lity y as a fiel field-i d-inst nstall alled ed com compon ponent ent.. It is int intend ended ed sol solely ely as a fac factor tory-i y-inst nstall alled ed component compo nent of other equipment equipment where its accep acceptabili tability ty is deter determined mined by the certification certification organ organizati ization. on. SA2.8 REC SA2.8 RECOGNI OGNITIO TION N MAR MARKIN KING G – A dis distin tincti ctive ve Mar Mark k of the certifi certificat cation ion org organi anizat zation ion tha thatt the manufacturer is authorized to apply to Recognized Components as the manufacturer’s declaration that they conform to the requirements of the Standard. SA2.9 VARIAT VARIATION ION NOTICE (VN) – A document used to record observed differenc differences es between a produ product ct or manufacturing process and the description of the product or process in the Procedure and/or Standard. SA3 Respon Responsibilit sibility y of the Manufacturer Manufacturer SA3.1 It is the manufact SA3.1 manufacture urer’s r’s res respon ponsib sibili ility ty to res restri trict ct the use of the Recognitio Recognition n Mar Markin king g to tho those se products specifically authorized by the certification organization that are found by the manufacturer’s own quality qualit y assur assurance ance program to comp comply ly with the Proce Procedure dure description. description. SA3.2 The manufacturer manufacturer shall confine all Recog Recognition nition Markings Markings to the location or locations authorized authorized in the Procedure. SA3.3 During hours in which the manufacturer’ manufacturer’s s facil facilities ities are in opera operation, tion, the manufacturer manufacturer shall permit the field representative free access to any portion of the premises where the plastic material is being produced, stored or tested. SA3.4 The Fiel SA3.4 Field d Repr Represen esentati tative ve shal shalll be perm permitte itted d to selec selectt a suf suffi ficien cientt quan quantity tity of mat materia erial, l, representative of current production. The manufacturer shall mold this material into test specimens, of a size and quantity, as indicated in the Procedure, for the purposes of the Follow-Up Test Program at the Certifi Cer tificat cation ion Org Organi anizat zation ion.. The pac packag kaging ing and shi shipme pment nt of the these se sam sample ples s is the res respon ponsib sibilit ility y of the manufacturer. SA3.5 A material that is found to no longer be in compliance compliance with the requirement requirements s of the certification certification organization shall be corrected by the manufacturer if the Recognition Mark is to be used on the product. If the noncompliance was the result of a manufacturing process, the manufacturer shall check subsequent production until it is certain that the process has been corrected and the noncompliance will not reoccur. SA4 Respon Responsibilit sibility y of the Field Representativ Representative e SA4.1 At each visit to the manuf manufactur acturer’s er’s facility, facility, the Field Representati Representative ve shall review a repr represent esentative ative sampli sam pling ng of pla plasti stic c pro produc ductio tion n whi which ch bea bears rs the Rec Recogn ogniti ition on Mar Markin king, g, to ass assure ure tha thatt the Rec Recogn ogniti ition on Marking Mar king has been applied in acco accordan rdance ce with this supp suppleme lement, nt, and the Procedure Procedure description description.. An inspection report shall be completed after each visit. SA4.2 Any observed observed differences differences between the product product marking and the descr description iption of the marking in the Procedure and/or Standard shall immediately be called to the attention of the manufacturer. Any observed differences shall be confirmed in a Variation Notice.
AUGUST 20, 2009
POLYMERIC MATERI AL ALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
SA3
SA4.3 Produ Production ction that is found to no longer be in compliance compliance with the requirement requirements s of the certification certification organization shall be brought into compliance by the manufacturer if the Recognition Marking is to be used on the product’s product’s pack packagin aging. g. If the nonnon-com complia pliance nce was the res result ult of a man manufac ufactur turing ing pro process cess,, the manufacturer shall check subsequent production until it is certain that the process has been corrected and the noncompliance will not recur. The Field Representative shall verify that the product marking continues to be in compliance with the requirements of the certification organization. SA4.4 Produ Production ction that does not comp comply ly with the provisions provisions of these follow-up follow-up inspection inspection instructions instructions shall have hav e the Rec Recogn ognitio ition n Mar Markin king g rem remove oved d or obl obliter iterate ated. d. The man manufa ufactu cturer rer sha shall ll sat satisf isfy y the fiel field d represent repre sentative ative that all Recogn Recognition ition markings are remo removed ved or oblite obliterated rated from rejec rejected ted mate material. rial. Those Recognition markings not destroyed during the removal from the product packaging shall be turned over to the field representative for destruction. If rejection of production is questioned by the manufacturer, the manufacturer may hold the material at the point of inspection, typically at the factory, pending an appeal. SA5 Select Selection ion of Samples for Follow-Up Follow-Up Testing SA5.1 The Fiel SA5.1 Field d Rep Repres resent entativ ative e sha shallll ran random domly ly sele select ct rep repres resent entati ative ve sam samples ples of pro produc ductio tion n for the purposes purpo ses of follow follow-up -up testing at the Certification Certification organization. organization. The sampl sample e select selection ion inter interval val shall be specified specifi ed by the Certification Certification organization, organization, and the Field Repre Representa sentative tive shall assur assure e that all select selected ed samples are properly identified through the use of sample identification tags provided by the Certification organiz org anizati ation. on. The fol follow low-up -up tes tests ts per perfor formed med at the Cer Certifi tificat cation ion org organi anizat zation ion are des descri cribed bed in the Follow-Up Test Program″ Section Section of this Supplement. ″ Follow-Up SA6 FollowFollow-Up Up Test Program Program SA6.1 The following tests are to be performed performed by the Certification Certification organization organization on samples received from the Field Representative. SA6.1.1 FLAMM SA6.1.1 FLAMMABILI ABILITY TY TEST – Test specimens specimens are to be subjec subjected ted to the appropriate appropriate burning tests, tests, indicated in the Procedure, in accordance with the methods described in UL 94, Tests for Flammability of Plastic Materials for Parts in Devices and Appliances. The classifications obtained in the Follow-Up Tests are to be the same as those indicated in the Procedure. SA6.1.2 QUALIT SA6.1.2 QUALITATIVE ATIVE INFRARED INFRARED ANALYSIS – An infra infrared red spectrum spectrum of the material material is to be obtai obtained ned by means of an infrared spectrophotometer in accordance with the methods described in Infrared Spectroscopy, Section 43 of UL 746A, Polymeric Materials – Short Term Property Evaluation. Instrument settings used in obtaining the spectrum shall be identical to those used in obtaining the original spectrum of the material referenced in the procedure. The spectrum obtained shall indicate the same composition as that recorded in the spectrum obtained under the original investigation. SA6.1.3 THERMO SA6.1.3 THERMOGRAVIM GRAVIMETRY ETRY – A thermogram thermogram of the mate material rial is to be obtained by means of a thermal analyzer with a thermogravimetic module in accordance with the methods described in Thermogravimetry, Section 46 of UL 746A, Polymeric Materials – Short Term Property Evaluations. Instrument settings used in obtaining the thermogram shall be identical to those used in obtaining the original thermogram of the material referenced in the procedure. The thermogram obtained shall indicate the same characteristic weight loss over the programmed temperature range as that recorded in the thermogram thermogram obtain obtained ed under the origin original al invest investigatio igation. n.
SA4
POLYMERIC MATERIALS – LONG TERM PROPERTY EVALUATIONS - UL 746B
APRIL 17, 2009
SA6.1.4 SA6.1. 4 A the thermo rmogra gram m of the materia materiall is to be obt obtain ained ed by means of a the therm rmal al ana analyz lyzer er with a DSC (Differential Scanning Calorimetry) module in accordance with the methods described in Section 47 of UL 746A, Polymeric Materials– Short Term Property Evaluations. Instrument settings used in obtaining the thermogram shall be identical to those used in the original thermogram of the material referenced in this proced pro cedure ure.. The the thermo rmogra gram m obt obtain ained ed sha shall ll ind indica icate te the sam same e gen genera erall the therma rmall res respon ponse se ove overr the progra pro gramme mmed d tem tempera peratur ture e ran range ge as tha thatt rec record orded ed in the the thermo rmogram gram obtained obtained und under er the ori origina ginall investigation. SA6.2 Upon completion completion of follow follow-up -up testing, the Certification Certification organization organization shall report the results to the manufacturer.