Splicing of Steel Cable Conveyor Belts
h t a n r o i c n N r o i e m i t A d E
Splicing Manual 1
Contents
Page
I. Range of Application
3
II. Produc Products ts for Splicing Splicing Steel Cable Belts
4
III. Tools and Equipment
4
IV. General General Conditions for Splicing Splicing Steel Cable Belts 1. Work place 2. Conveyor belt 3. Equipment and tools 4. Splicing products 5. Ambient conditions 6. Documentation 7. Precautions
5 5 5 5 5 5 5 5
V. Construction Construction and Dimensions Dimensions of Steel Cable Belt Splices 1. Splicing methods 2. Construction 3. Determination of splice and step length
6 6 6 8
VI. Splicing of Steel Steel Cable Belt Belt 1. Preparations for splicing 2. Preparing the belt edges 3. Assembly of cover pads 4. Prep Prepari aring ng a and nd p plac lacing ing the bot bottom tom cover cover pad pad 5. Matching and laying the cables 6. Placing the top cover pad 7. Curing the splice 8. Completing the splice
10 10 11 16 16 18 22 23 24
VII. Questionnair Questionnaire e for REMA TIP TOP Splicing Kits
25
VIII. REMA TIP TOP Splicing Record Sheet
26
2
I. Range of Application This manual describes the splicing of steel cable conveyor belts (DIN 22131) with rubber covers made of the following polymers: - Natural rubber - Styrene butadiene rubber - Isoprene rubber - Butadiene rubber - or a mixture of above polymers, e.g
NR* SBR* IR* BR* NR/SBR*
In case of doubt, consult the supplier of the conveyor belt about the rubber grade. For splicing steel cable belts with a breaker please contact your REMA TIP TOP distributor. Splicing can be done in the workshop or on site.
* Abbreviations according to DIN ISO
3
III. Tools and Equipment
II. Products for Splicing Steel Cable Belts STB COVER STOCK Ref. No. 528 8889 - 538 0529
43" & 53" wide by 36 ft & 1/16" to 3/8"
STZ TIE GUM RUBBER Ref. No. 538 8889 - 538 0938
43" & 53" wide by 36 ft & .060 to .125
STZ NOODLE STRIPS Ref. No. 538 0952
.080 to .120 gauge by .200 to .275 width
STL-RF CEMENT (NON-FLAMMABLE) Ref. No. 538 8882 - LRF - QT Ref. No. 538 8882 - LRF - GAL Ref. No. 538 8882 - LRF - 5GAL Ref. No. 538 8882 - LRF - 200L
quart gallon 5 - gallon 55 - gallon
STL-RF4 CEMENT (FLAMMABLE) Ref. No. 538 8882 - RF4 - QT Ref. No. 538 8882 - RF4 - GAL Ref. No. 538 8882 - RF4 - 5GAL Ref. No. 538 8882 - RF4 - 200L
quart gallon 5 - gallon 55 - gallon
REMA CLEAN #13 SOLVENT (NON-FLAMMABLE) Ref. No. 595 9020 1000549 quart Ref. No. 595 9046 1000559 gallon Ref. No. 595 tri 1000569 55 - gallon REMA CLEAN #50 SOLVENT (FLAMMABLE) Ref. No. SOL FLAME QT quart Ref. No. SOL FLAME GAL gallon Ref. No. SOL FLAME 5GAL 5 - gallon Ref. No. SOL FLAME 55GAL 55 - gallon BROWN COATED RELEASE PAPER Ref. No. 538 1030 76100 76" wide x 100' long PRESSURE COMPENSATION CLOTH Ref. No. 538 1009 41 49" wide x 41' long
Splicing shelter / tent Polyethylene film (PE film) Cover cloth Screw clamps Measuring tape Ruler (in./mm) Metal rule Flat angle Marking crayon (white) Rubber marker Plumb line 6" knife Off-set knife Whetstone Scissors Pincers Vise grip No. 2 Vise grip No. 3 Chain or cables winches Cable cutters Angle grinder Hand brush Cement brushes Stitchers & Rollers Hammer Cable drum Safety goggles Work gloves Buffing motor with flexible shaft Rotating wire brushes Grooved wire brushes RTT Belt stripping system Vulcanizing press incl. edge bars and clamps Thermometers Rubber Cut Thickness Gauge STZ Extruder gun
STZ NOODLE EXTRUDER GUN Ref. No. 517 5174
REMA TIP TOP Splicing Kits for other steel cable belt cover grades are available on request! Please see section VII on page 25.
For detailed information about equipment, measuring instruments and tools please refer to: REMA TIP TOP Industrial Programme.
4
IV. General Conditions for Splicing Steel Cable Belts ´ 1. Work place In order to ensure quality and durability of a splice, a clean and sheltered work place as well as correct use and application of the splicing products are essential. The exposed surfaces of stripped cables, bevel cuts and cover pads must be kept absolutely clean. 2. Conveyor belt Only clean and dry conveyor belts can be spliced reliably. Dirty or contaminated belts must be cleaned. Water-soluble contaminations should be scraped off and then washed away with water and dried. Oil and grease should be removed with Cleaning Solvent. 3. Equipment and tools Tools and equipment must be in perfect working order. Measuring instruments have to be calibrated. 4. Splicing products REMA TIP TOP Splicing products are suitable for cable belts with RMA grade I & II rubber covers. Splicing products have to be stored in a dry and dark place at a temperature of max. 25oC (77oF) in accordance with DIN 7716. Check expiration dates and dispose of outdated and contaminated products. 5. Ambient conditions Any influence of humidity, e.g. formation of condensation water (temperature falling below dew point) must be absolutely avoided. Precondition products to ambient temperature if necessary. Erect a splicing shelter/tent for protection against sun, dust, wind, rain etc. 6. Documentation During the splicing operation all irregularites and special conditions have to be recorded. The record sheet must be signed by the supervisor at the end of each shift. 7. Precautions Observe safety precautions on the cans. Note: Our recommendations result from field tests and years of experience. However, in view of the different materials and work conditions beyond our control, we recommend to make corresponding tests locally in any case. We cannot assume any kind of liability resulting from these recommendations.
5
V. Construction and Dimensions of Steel Cable Belt Splices 1. Splicing methods Splices on steel cable belts in accordance with DIN 22131 can be 1-step or multi-step splices in rhombic (belt width x .4) or rectangular shape.
Fig. 1
Rectangular shape
Rhombic shape
The loadability of both the rectangular and the rhombic shaped splice is similar. Usually a rectangular splice is preferred, because it can be done more easily. The following description refers to a rectangular splice. 2. Construction Cable diameter d and cable pitch t as well as the minimum breaking strength of a cable and the dynamic cable tear-out strength in the splice area dictate length and geometrical construction of a splice. The geometrical construction is determined by - number of steps - length of steps - length of transitions - cyclic cable laying sequence (incl. cut cables) - cable pitch in the splice area (noodle thickness). The construction is also influenced by - distance between butted cables - stepping of cable ends - cable laying corrections and laying cycle modifications.
The gap between butted cables has to be min. 3 times and max. 4 times the cable diameter d. The cable ends should be staggered in order to reduce the flexing load, when the belt runs over the pulleys. This mainly applies to belts with thin top covers. Cables on the belt edges should not be cut. They should be layed in full length in opposite running direction of the belt. Deviations of the cable laying scheme should be moved to the belt center area, because the edge zones are exposed to a higher load.
6
Fig. 2
Transition zone
Transition zone
If a steel cable belt is equipped with a breaker, a breaker should be applied in the splice area corresponding to the belt construction. Between breaker and transition zones where the top covers are bevelled, there should be a gap of approx. 2 In.
lv =
Length of splice
lq =
Deflecting zones of cables
lp =
Staggering of cable ends
lst =
Minimum step length
ls =
Distance between butted cables (3 to 4 x d)
d =
Steel cable diameter
Fig. 3 Transition zone O
2 inch
O
20 - 30
Top cover pad Breaker Steel cable Belt
Splice
Bottom cover pad
20O - 30O
7
3. Determination of splice and step length The splice length lv includes: - Deflection zones of cables lq - Staggering of cable ends lp - Minimum step length lst - Distance of butted cables ls
Step lengths and splice lengths Belt type (DIN)
Number of steps
Min. step length l st
STZ Noodle Rubber Splice length lv
Thickness x Width Inchs
St 1000
1
24"
32"
.080 x .235
St 1250
1
24"
32"
.080 x .275
St 1600
1
24"
32"
.080 x .275
St 2000
2
16"
46"
.100 x .275
St 2500
2
20"
54"
.100 x .390
St 3150
2
26"
66"
.080 x .390
St 3500
3
26"
98"
.100 x .430
St 4000
3
30"
110"
.100 x .430
St 4500
3
32"
116"
.080 x .470
St 5000
4
36"
170"
.100 x .510
St 5400
4
40"
186"
.100 x .510
Other splicing methods The cable laying schemes as well as the step lengths, deflecting zone lengths and the splice lengths indicated may be modified if necessary; e.g. when splicing different belt types (mixed splice, bel ts ends with differnt amount of cables). Such modifications require the approval of the plant operator.
8
Running direction of belt
4"
4" 2"
2"
1-step splice (sectional view) Fig. 4
Gurtlaufrichtung Running direction of belt 6"
6" 2"
2"
2"
2-step splice (sectional view) Fig. 5
Gurtlaufrichtung Running direction of belt
8"
8" 2"
2"
2"
2"
3-step splice (sectional view) Fig. 6
Gurtlaufrichtung Running direction of belt
10"
10" 2"
2"
2"
2"
2"
4-step splice (sectional view) Fig. 7
9
VI. Splicing of Steel Cable Belt 1. Preparations for splicing 1.1 Prepare tools, equipment and splicing materials. 1.2 Erect a splicing shelter, install a work table and the vulcanizing press: The entire work area has to be adequately protected by the shelter from environmental influences. The work area consists of the lower part of the press (traverses and heating platens) and approx. 10 - 12 ft. long wooden work tables at either end of the press. 8" Fig. 8
The heating platens must be flush with the surfaces of the work tables in order to avoid tensions at the belt ends. The heating platens must be at least 8" longer than the splice on either side and at least 3" wider than the belt on each side (edge bars must be fully covered by the heating platens).
3"
1.3 Aligning the belt ends Place and align belt ends on lower part of press and work tables, ensuring that both ends are overlapping on the press by at least the splice length lv plus 4". Secure belt ends in this positon with clamps. Fig. 9
10
2. Preparing the Belt Ends 2.1 On both belt ends establish and mark - the belt center line - the perpendicular reference lines and - the belt cover transition lines. Establish and mark center line of belt by measuring across width of belt at three points in length of each belt end at a distance of approx. 6". At least two center markings on each belt end must be outside the splice area. The establishment of the center line is easiest done with two rulers (Fig. 10). The three center markings on each belt end are then connected by means of a chalk line which represents the belt center line. This center line ensures exact alignment of the belt ends, which is indispensable for straight belt running. The center line outside the splice area must be durable enough to remain evident throughout the entire splicing operation!
Belt center line
Fig. 10
Placing the rulers
Fig. 11
Destroyed or missing rubber edges must be considered. The width of the rubber edge is established by measuring the width of the carcass at suitable areas of the belt ends. Establish a perpendicular reference line across both belt ends outside the splice area. On narrow belts this can be done by placing a metal square onto the center line. On wide belts it is recommended to establish the reference lines as follows (Figs 11 to 13): Outside the splice area select a point A on the center line. Mark points B and C on the center line equidistant to point A (AB=AC) (Fig. 11).
Fig. 12
Now describe a circle with the same radius around points B and C by means of a plumb line and a pen. The points of intersection of both circles must still be on the belt. These intersections are points D and E (Fig. 12).
Fig. 13
Reference line
A line drawn between these two points will be perdendicular to the belt edges and forms the reference line, which should pass point A for additional control (Fig. 13)
11
The reference lines are now marked by cutting small notches into the belt edges.
For exact measuring, another 4" are added to the splice length on either side and marked.
The notch marks of the reference lines on both edges of the belt ends are now the reference points from which the splice length lv is measured and marked (Fig. 14).
The marks now established for the splice length are connected on the belt with a chalk line or with a rule and a pen. These lines are the belt transition lines for the bevel cuts on carrying and running side of the belt.
Fig.14 Belt end
Reference line Transition line
Reference line Center line
Transition line
Belt end
4"
4"
a = Distance between reference lines (must be equal on both sides)
Fig. 15
Transition line
Center line
2.2 Cut off the rubber edges along the outer steel cables from belt transition lines to belt ends with a long knife (Fig. 15).
Transition line Fig. 16
4"
Center line 2.3 Bevel cut through top cover down to the steel cables along the belt transition line using a Don Carlos knife held at an angle of approx. 30 o (Fig. 16).
12
2.4 Removing top and bottom cover and stripping of steel cables Center line
a) Conventional manual procedure Cut the rubber covers on the carrying and running side into parallel strips with a Don Carlos knife (15" - 30" wide according to belt width) in length direction of the belt. Lift the rubber cover with pincers at one corner of a strip in the area of the belt transition line and cut it free with the Don Carlos knife just above the steel cables, until the cover can be gripped with a REMA TIP TOP Vise Grip. By means of the vise grip, a winch and continuous cutting (just above the steel cables) the complete rubber cover is removed (Fig. 17).
Fig. 17 Transition line
Center line
During this operation the rubber cover is under tension and has to be secured with a rope in order to protect the work men in case the vise grip slips off. When cutting off the rubber cover hold the knife at such an angle that the steel cables remain covered with rubber.
Fig. 18
ca. 1/2" Transition line
The exposed carcass must be protected from contamination and placed onto a clean surface (e.g. PE film). After having removed the rubber covers on both sides of the belt, cut out the rubber between the steel cables with a 6" knife to within 1/2" of the bevelled transition zone (Fig. 18). Fig. 19 The stripped cables should still be covered with rubber (cubed cable rubber). On cables which are strongly twisted the corners should be trimmed off also (Fig. 19).
Cables with a diameter of 8 mm and more: Before cutting out the rubber between the cables notch the rubber between the cables at an angle of approx. 45o, resulting in a hexagonal rubber (Fig. 20).
Fig. 20
Stripped cables should be handled with clean gloves only and placed onto a clean surface (PE sheet).
13
Now install the REMA TIP TOP Cable Stripping System according to instructions and start stripping the cables from the left side of the belt in direction belt end.
b) Stripping the steel cables with the REMA TIP TOP Cable Stripping System With the REMA TIP TOP Cable Stripping System the cables are stripped in one single, time-saving operation, without prior removal of the top and bottom cover. This mechanical stripping system requires the following additional preparations: - Approx. 6" - 8" from the transition line draw an additional, parallel line on top cover side and bottom cover side of the belt ends. - Cut the rubber cover along this line straight down to the cables. - Remove the rubber cover between transition line and the vertical cut in the conventional, manual way.
Fig. 21
Please make sure to use cutting blades corresponding to the cable diameter. After stripping, the result should be a nearly round cable, with .010 of rubber embedded on the cable. Stripped cables should be handled with clean gloves only and placed onto a clean surface (PE film).
REMASTRIP-Cutting unit
Pulling cable
Pulling unit
6" - 8" 2.5 Buffing the rubber embedded cables
(Fig. 22)
Carefully buff the rubber embedded cables with a grooved REMA wire brush. Avoid overheating, shiny spots and scorching of the rubber. Buffing will automatically break the edges of cubed cable rubber. Non-adhering or loose rubber has to be removed. A minimum of bare metal should be exposed. A small amount of such exposure can be tolerated. The strength of a splice depends on the level of cable adhesion to the original rubber embedding it. The new STZ rubber bonds to the original cable rubber. The splice strength depends on the shear adhesion of a rubber to rubber bond, rather than a rubber to metal bond. Damaged, corroded or bare cables have to be buffed until they are bright. An excessively damaged cable has to be removed. In case of several damaged or corroded cables the operator should be informed immediately, who will have to decide whether the splicing job should be continued or a new belt installed. The number and condition of such cables and partially bare cables should be noted in the splicing record.
Fig. 22
14
2.6 Buffing the transition zones On the top cover and bottom cover side of both belt ends the rubber surfaces of the transition zones and another 1" - 2" on either side of them must be thoroughly buffed with a rotating wire brush. Overheating, shiny spots and scorching of the rubber should be avoided.
2.7 Removing the buffing dust The buffing dust has to be thoroughly removed with a clean hand brush. Place belt ends back onto the work tables and arrange the cables on a clean surface (PE film).
Fig. 23
center line
approx 1/2" - 3/4" 2.8 Applying heating solution Apply two thin and even coats of REMA TIP TOP STL-RF or STL-RF4 cement to the transition zones and the cables (Fig. 23). Allow the first coat to dry completely before applying the second coat.
approx 1/2" - 3/4" PE protection film STL-RF / STL-RF4 Cement
2.9 Aligning the belt ends Align lower part of the vulcanizing press (traverses and heating platens). In case of low ambient temperature preheat the heating platens to max. 100 oF (40 oC). Establish number of cables of each belt end and mark the carcass center. Align the belt ends under consideration of splice length lv, the belt center line and the carcass center line on each belt end and mark correct alignment with a chalk line. Now the center lines on both belt ends must form one straight line. The distance of the reference lines on both belt edges must be equidistant (a = a - see Fig. 14 on page 12). Secure both belt ends with clamps.
15
3. Assembly of cover pads The assembly of top cover pad and bottom cover pad is usually done in the workshop. They consist of .080 thick STZ tie gum rubber and STB cover stock.
The tie gum rubber side is covered with a red protection film; the cover stock side is covered with a green protection film.
Required minimum thickness of cover pads: - Thickness of belt cover plus .040.
For splices with breaker the STZ tie rubber is .120 thick. The breaker is placed between STB cover stock and STZ tie gum rubber and should not extend into the rubber edge zones and leave 2" between breaker edge and both transition zones. In this case the minimum cover pad thickness is: Thickness of belt cover plus .080. Type and construction of the breaker required should be coordinated with the operator or the belt manufacturer.
Dimensions of the cover pads: - Belt width plus 6" - Splice length plus 10" For large splice lengths and wide belts the cover pads may be made up in two or more parts.
4. Preparing and placing the bottom cover pad 4.1 If necessary place thin metal strips over the joints on lower heating platens. Place strips of 10" - 12" wide Pressure Compensation Cloth over the transition zones and the splice edge zones in such a manner, that they can be folded up later in order to cover the complete rubber edge. Then cover the complete heating area with Brown Silicone Coated Release paper (Fig. 24).
Fig. 24
4.2 Remove the green protection film from the cover stock side of the cover pad. Place the cover pad onto the covered heating platens and align. The red protection film (STZ rubber side) is now on top. In case of several partial cover pads also coat the bevelled edges with STL-RF / STL-RF4 Cement and allow to dry until they are still slightly tacky. Then join the coated edges without trapping air and stitch together .
Brown Release Paper
Cloth
Pressure Cloth strips Brown Release Paper Pressure Cloth
16
4.3 In the area of the transition zone remove the red protection film by approx. 4". Place one belt end onto the cover pad and mark first splice edge. Fold belt end back again and bevel cut the cover pad at an angle of approx. 30o corresponding to the bevel cut angle of the transition zone. Before handling the belt ends bundle the steel cables and wrap them into PE film.
Now apply a thin and even coat of STL Cement to the bevelled edge of the cover pad. If the coat of STL Cement on the transition zone is no longer tacky enough, apply another coat and allow both coats to dry until they are still slightly tacky. Place the transition zone of the belt onto the bevelled edge of the cover pad, press on and tap down with a hammer (Fig. 25).
Fig. 25
.080 STZ 3/8" STB Cover pad 4.4 The transition zone of the other belt end is matched and placed in the same way (Fig. 26).
Fig. 26 Again check the correct alignment of the belt center lines and also the splice length lv and adjust/correct if required (Fig. 27).
Fig. 27
17
5. Matching and laying the cables 5.1 Completely remove the red protection film from the bottom cover pad and mark the step lines ( lst and lp) for laying the cables according to the specified laying scheme. Scribe these lines on the cover pad with a knife tip. These lines must still be visible after coating with STL Cement. The step lines can also be marked by placing STZ Noddle rubber strips onto the established lines. Place clean PE film or similar over the bottom cover pad, leaving exposed approx. 4" in the center in length direction of the belt. The tack of the tie gum rubber, which will be exposed further step by step can further be improved by applying a very thin coat of the STL Cement.
Fig. 28
lv =
Length of splice
lq =
Deflection zones of cables
lp =
Staggering of cable ends
lst =
Minimum step length
ls =
Distance between butted cables (3 to 4 x d)
d =
Steel cable diameter
18
5.2 Laying the cables This operation is always started at the center of the splice. Odd number of cables 1-step splices: The center cable of the second belt end may be cut at the bevel cut. It will not be deflected, but laid directly onto the belt center line. Belt running direction
Belt center line and center cable Fig. 29
2-step and multi-step splices In both cases start with the center cable of the first belt end, which in case of a multi-step splice is a long cable. This cable is deflected by half the cable pitch towards the belt center li ne. Belt running direction
Belt center line and center cable
Fig. 30
On the second belt end also start with the center cable, which then is deflected towards the other side of the belt center line by half the cable pitch and laid in the matching length in accordance with the cable cycle. All further cables are laid according to cable laying scheme proceeding to the edge on both sides. Even number of cables On both belt ends start with the left cable of the two center cables (as seen from the first belt end) which are staggered towards the marked belt center line. Belt running direction Belt center line and left center cable
Fig. 31 Even and odd number of cables
If the number of cables in the belt ends are not matching, start laying the center cable of the belt with the odd number of cables onto the belt center line and then proceed according to the specified cable laying scheme. Belt running direction
Belt center line and center cable Fig. 32
19
5.3 Laying the cables After having determined how to start laying the cables, all further cables are cut according to the marked step lines and pressed onto the bottom cover pad in accordance with the specified cable laying scheme (Figs. 4 to 7).
Never cut two cables next to each other! If the cables are bent towards the belt center compensate by placing additional STZ noodle rubber strips.
The gap between butted cables must correspond to between 3 and 4 times the steel cable diameter!
STZ noddle rubber strip is placed edgewise between the cables, after having removed its protection film (Fig. 33). When laying and pressing on the STZ tie rubber strips a uniform distance between the cables must be ensured, especially at the cable ends, which are exposed to the maximum rubber shearing force within the splice.
The dimensions of the STZ noddle rubber strips are indicated in the table on page 8 and ensure that the cables are laying straight. During the laying operation continuously check that the cables are laying straight. If this is not the case, despite of careful laying of cables and noodle rubber, proceed as follows: If the cables are bent towards the edges of the splice, try to move the cables closer together by tapping them with a hammer and pulling the noodle rubber at the same time. If this does not bring the desired result, the only way is to cut a cable on the second belt end first and then, if still necessary, also on the first belt end.
The edge cables must always be long cables from the first belt end. This is achieved by checking the cable laying scheme at least 10 - 15 cables before the edge cables are reached. If according to the laying scheme the edge cable will not be a long cable from the first belt end, an initial adjustment can be made by cutting a cable from the second belt end at least 10 - 15 cables away from the edge cable. Edge cables must never be cut! The cables to be cut always have to be at least 10 -15 cables away from the edge. In case of a 1-step splice a cable has to be cut on one belt end only which usually is the only way of correcting. Exceptions are: - when the center cable of the second belt end with an odd number of cables has been cut in the beginning (para. 5.2) or - when the number of cables in the first belt end is smaller by one cable and a cable has already been cut on either side of the splice. On multi-step splices there is an increased number of possibilites for adjustment.
STZ STB
Fig. 33
STZ noodle rubber strips
20
Cutting one or more cables will solve a problem for the necessary adjustment. If there is sufficient space in the edge area, it is recommended to place a thicker strip or two strips of STZ noodle rubber. A STZ noddle rubber strip is also placed along the edge cables and pressed on. When the last cables are laid, there should be sufficient space for the rubber edge.
Fig. 34
5.4 After having laid all cables mark the splice edges with a chalk line and trim excess rubber. Apply a coat of STL-RF / STL-RF4 Cement to the edge of the bottom cover pad and to the excess STB cover stock. Allow these coats to dry until they are still slightly tacky (check with back of finger). In case of overdrying apply another coat. Build up edges with excess STB cover stock to the upper level of the cables. The splice should now be slightly wider than the adjoining cured belt. Excess material will be trimmed later together with the top cover pad (Fig. 34). 5.5 Thoroughly and completely fill up all remaining gaps and cavities slightly above upper level of cables either manually or with the REMA TIP TOP STZ extruder gun.
21
6. Placing the top cover pad 6.1 Apply a generous coat of STL Cement to the buffed upper bevel cuts of the transition zones on both belt ends as well as to the built up rubber edges and allow to dry completely. 6.2 Before placing the top cover pad onto cables and rubber edges proceed as follows: - check the thickness of the cover pad - preheat the heating platens to max. 100 o F (40oC), if necessary - remove the red protection film from the tie rubber side. Depending on the tack of the already coated tie rubber apply another thin coat of STL Cement. In case of several partial cover pads also apply a thin coat of STL Cement to the edges.
6.3 When placing the top cover pad avoid trapping air. Then remove the green protection film. Press on and stitch the top cover pad vigorously from the center outwards or in direction of the butt joints respectively and firmly tap down with a hammer in the transition zones (Fig. 35). Remaining air within the splice area can be evacuated by making approx. 4" - 6" long cross cuts down to the cables (not in case of top cover pads with a breaker) and using a awl.
Fig. 35
6.4 Trim excess rubber in the transition zone with an offset knife. Mark the splice edge with a chalk line and trim with a long knife (Fig. 36). The REMA White marking Rubber and be applied at this time (see page 25 sec 8.3)
Fig. 36
6.5 Again check the correct alignment of the belt center lines of both belt ends with a string. Deviations can now still be corrected. This final control/correction is important for straight running of the belt and therefore indispensable (Fig. 37).
Fig. 37
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7. Curing the splice 7.1 Apply 8" - 10" wide strips of Pressure Cloth onto the transition zones of the top cover pad and fold the lower shirting strips around the splice edges (Fig. 24 on page 16). Then cover the complete heating area with Brown Silicone Release Paper and trim on either end of the splice. Now the edge bars (edge irons) are applied on both sides of the splice and pressed against the belt edges with edge clamps, which are mounted outside the press area. The edge bars must be approx. 1/16" thinner than the belt (Fig. 38).
Fig. 38
7.2 Assemble top platens and then place the upper traverses in line with the lower traverses. The upper heating platens also must be at least 8" longer than the splice on either side and at least 3" wider than the belt on each side. The edge bars must be fully covered by the heating platens. The arrangement or layout of the heating platens must be noted in the splice record.
When aligning the heating platens and the traverses it has to be ensured that the platen joints in direction of the belt edges are supported by the traverses and that the first and last traverse is located outside the splice area. Now the pressure bolts are installed and have to be tightened evenly and simultaneously in each travers. Then secure the edge bars by means of wedges and come-a-longs (Fig. 39).
Fig. 39
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8. Completing the splice 7.3 Attach the electrical connections and pressure systems of the vulcanizing press observing the operating instructions of the press manufacturer. The press must produce a minimum pressure of 180 PSI (specific pressure: 12 bar).
8.1 Remove vulcanizing press, strips of cloth, brown silicone release paper and inspect the splice. Check for correct vulcanization (absence of porosity or blisters, elasticity, thickness and Shore hardness).
7.4 Increase pressure while temperature rises and observe temperature on all heating platens. Platen temperature uniformity should be within +/- 5 oF (10oC ) of the selected temperature. Higher deviations must be recorded.
8.2 Trim edges, remove material overflow and make any other appearance modifications as may be necessary.
7.5 Apply specific pressure when all heating platens have reached a temperature of between 212 oF (100oC) and 230oF (110oC) and maintain this temperature for a period of approx. 5 minutes by disconnecting the electrical connections at 230oF (110oC) and connecting again when the temperature has dropped to 212 oF (100oC). At this temperature range the rubber develops its optimum flowing properties. Never exceed the permissible specified pressure! 7.6 Then continue increasing the temperature. The curing time starts when the temperature on all heating platens has reached 293 oF (145oC). The curing time depends on the belt thickness. REMA TIP TOP products require a curing time of 3 minutes per 1/32" belt thickness, but not less than 30 minutes. 7.7 Set the electrical connections at a temperature of 298 oF (148oC) and connect again when the temperature has dropped to 293 oF (145oC). Repeat this operation until the curing time is completed. If necessary place thin metal strips over the joints prior to placing the top heating platens. 7.8 When curing is completed allow the heating platens to cool down to 140oF (60oC) before releasing the pressure.
8.3 The splice should be durably marked with a splice number (DIN 22129) by means of the REMA TIP TOP Rubber Cutter or the REMA TIP TOP Branding Iron or the REMA White Marking Rubber. Marking example: 1/4/98 RTT 14 8
1/4/98
RTT 14
8
Splicing date (day/month/year) 01.04.98 Contractor REMA TIP TOP Splice number No. 14
ID abbreviation of vulcanizer 8.4 The conveyor belt can be put into operation after the splice has cooled down to ambient temperature. 8.5 Finally the splice record sheet must be completed. All irregularities occurred during the splicing operation should be registered. The record sheet should be signed by the Supervisor of the contractor and countersigned by the operator.
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VII. Questionnaire
REMA TIP TOP Splicing Kits for Steel Cable Conveyor Belts
Please complete and send this questionnaire together with your inquiry or purchase order. In order to ensure quotation/supply of the correct splicing kit, the following details are required:
Belt Manufacturer
......................................................
Belt Specification acc. DIN
ST ................................................
Rubber Grade
......................................................
Cable Diameter
.................................................
Cable Pitch
.................................................
Belt width
.................................................
Top Cover Thickness
.................................................
Bottom Cover Thickness
.................................................
Specified Splice Length
.................................................
Splice Geometry
! rectangular
Breaker
!
.............................................................. Company Signature
Carrying side
........................................................... Place
! rhombic
!
(22o)
Running Side
................................. Date
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VIII. REMA TIP TOP Splicing Record Sheet 1. JOB DETAILS Customer: ...................................
Contact Name: ..................................
Job Card No.: ................................
Supervisor: .................................
Crew Names: ..................................................................................................
Date/Time: ..................................
Scope of Work: ...............................................................................................
Special Instructions: ................................................................................................................................................... ..................................................................................................................................................................................... 2. SITE INFORMATION Site Conditions: ...........................................
Accessibility: ....................................................................................
Weather: .....................................................Temperature: ................. oF/ oC Arrival/Dept.: .....................h/..................... h
Humidity: ......................%
Reported to: .....................................................................................
Belt isolated/locked by: ................................ Waiting time: .................................................................................... 3. BELT DATA Belt Manufacturer: .......................................
Belt Type:.................................. Belt Length: ................................
Cover Thickness: Bottom Cover: ...............
Top Cover: .............................
Cover Grade: ............................................ Belt Condition: ......................................................................... Splice Length: .......................................... ! ! !
Step Length: ..........................
Cables stripped manually Cables stripped with RTT Cable Stripping System Cables buffed with REMA grooved wire brush
Thickness
Left Side
Right Side
Leading end (first belt end)
..............
................
Trailing end (second belt end)
..............
................
Alignment:
1
2
3
Width of first belt end (leading end)
.........
.........
.........
Width of second belt end (trailing end)
.........
.........
.........
4. MATERIALS USED Splicing Product
STL Cement
STB-Cover Stock STZ - Tie Gum
STZ-Noodles
Manufacturing date Expiry Date
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5. CURING PROCESS Vulcanizing Press: Pressure System:
Manufacturer: ................. ! Hydraulic
Model: ........................................... ! Water Bag ! Mechanical
Heating Platens:
! Rhombic (22o)
! Rectangular
Number of pairs of traverses:
......................................
Thickness of edge bars:
......................................
Heat up time to 293 oF (145oC)
Time started: ............h
Time reached: ...............h
Temperature oF (oC)
Curing Time Heating Platens No.
Calculated Curing Time: ................mins
1
2
3
Pressure (PSI) 4
5
6
Gauge 1
Gauge 2
10 mins 20 mins 30 mins 40 mins 50 mins 60 mins 70 mins 80 mins 90 mins 100 mins 110 mins 120 mins Cooling down time to 140 oF (60oC)
Time started: .......h
Time reached: ........ h
6. FINAL QUALITY CONTROL Alignment:
! Correct
!
Off center ...........................inchs
Edge trimming:
!
Yes
!
No
Rubber Hardness (Shore A):
TopCover:.............................BottomCover: ........................................
Appearance of top and bottom cover surface: .......................... Splice marking: ...................................... Signature of Shift Leader: ..........................................................Date: ..................................................... 7. CUSTOMER SATISFACTION Professional
Acceptable
Unacceptable
Job organization ! ! ! Safety regulations ! ! ! Job performance / skills ! ! ! Tools and equipment ! ! ! Work force appearance ! ! ! Work finishing / cleanliness ! ! ! Time keeping ! ! ! Observations: ............................................................................................................................................. ................................................................................................................................................................... Date: ...............................Site Manager: .............................................Signature: ......................................
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Distributor:
