Submitted to: Mr. Salman Garment manufacturing Department
Background:
To determine the dimensional changes in woven and knitted fabrics when repeated laundering process domestically used, we do AATCC-135 test. Domestically washing temperature ranges from cold warm. For fabrics that are intended to be used in a form fitting garment, restoration techniques are sometimes used prior to determining the dimensional change. Techniques for this type of restoration are not standardized (hand pulling specimens in the length and width directions at multiple locations using an unspecified force). If restoration techniques are used, a description of the technique should be reported and results should be reported as restored dimensional change
Apparatus and material: Automatic washing machine, automatic tumble dryer, indelible ink marking pen and measuring tape or ruler.
Theory: Dimensional change: The change in the fabric dimensions is expressed as a percentage of the initial length and width. Change in fabric dimensions occurs in specified conditions. When dimensional change results in increase of the specimen dimensions then it is termed as growth. When dimensional change results in decrease of the specimen dimensions then it is termed as shrinkage. Laundering: The process used to remove soils and stains by washing the fabric/garment with an aqueous detergent solution is termed as laundering.
Procedure: y y
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10x10 in fabric samples are taken. Samples from which dimensional change specimens are to be taken should be representative of the fabric processing stage, finishing treatment, research lab trial, pallet, lot or end-product stage. Lay the sample on a flat surface. Selected test size, mark specimens parallel to the selvage or fabric length direction. Avoid use of the sample area within ten percent of the sample width. Specimens should be taken from areas with different lengthwise and widthwise yarns. Identify the length direction of the specimens before cutting them out of the sample. When possible, three specimens from each fabric should be used. One or two specimens may be used when insufficient fabric sample is available.
y y y y
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Then lines are drawn on the sample. Original Measurements and Specimen Size are taken. Then the sample is put in the laundering machine. Washer is set for washing cycle time. After the specified time the sample is taken and dried by laying it on the flat table and not making any stretch on the sample. Then measure the lines and calculation is done.
A) Tumble i. Cotton Sturdy ii. Delicate iii. Permanent Press (B) (B) Line (C) Drip (D) Screen
Results: Original length of reference = 8.9cm Original Origina l width =10.6cm After washing and drying Length = 8.6cm Width =10.3cm Dimensional Dimensiona l change % average For length
= (8.6-8.9)*100/8.9 (8.6-8.9)*100 /8.9
=- 0.3
Dimensional Dimensiona l change % average For width
= (10.3-10.6)*100/10.6 (10.3-10.6)*100 /10.6
= -0.3
Conclusion: If final measurement smaller than the original measurement results in a negative dimensional change which is shrinkage. If final measurement larger than the original measurement results in a positive dimensional change which is growth.
