Hypothesis:
Fabrics that are subject to shrinkage in water will lose their tendency to shrink when laterally constrained by some system of porous constraint.
In the case of cellulosic fibers, lateral constraint should offset the fibers natural tendency to swell and increase in crimp. In the case of wool, lateral constraint should offset the fibers tendency to felt.
Procedure:
Three identical 10" x 64" marked strips were cut from each of four different fabrics: wool, cotton, silk and rayon. All four fabrics were labeled as "dryclean only".
Each fabric strip was soaked for 30 minutes in 90 degree F water. While soaking, each strip "A" was constrained by being folded and sandwiched between a 12" square screen-mesh frame. Each strip "B" was allowed to float free. Each strip "C" was manually agitated.
Each strip "A" was allowed to dry at room temperature while still constrained within the frame. Each strip "B" and "C" was laid flat to dry at room temperature. All test strips were then measured for length.
Test Data:
Fabric Strip Length % Shrinkage
Wool A 64.00 0.0%
Wool B 63.50 0.8%
Wool C 61.88 3.3%
Cotton A 63.25 1.2%
Cotton B 62.50 2.3%
Cotton C 61.78 3.3%
Silk A 63.00 1.6%
Silk B 62.00 3.1%
Silk C 61.25 4.3%
Rayon A 61.75 3.5%
Rayon B 61.50 3.9%
Rayon C 61.38 4.1%
Preliminary Conclusion:
In all fabrics tested, strip "A" shrunk least. Therefore, constraint does help to reduce shrinkage.
Secondary Hypothesis:
The firmer, more uniform, and more finely porous the system of lateral constraint is, the less likely that shrinkage should occur.
Secondary Procedure:
Another 64" long strip of rayon was cut from the same bolt as that used previously. This time the folded rayon was sandwiched between a slightly curved piece of steel plate covered in buckram and a screen mesh material made from woven plastic fibers. The holes in this screen were about two-thirds the size of the previously used aluminum screen; and, although no method to measure the pressure was available, a conscience attempt was made to manually secure the screen over the curved plate so that the pressure against the rayon would be firmer and more uniform than that achieved in the first procedure. The fabric was soaked in 90 degree F water for 30 minutes and allowed to dry in the constraining device; then it was measure for length, The result is below:
Strip Length % Shrinkage
Rayon A-2 62.25 2.7%
Conclusion:
Fabrics that are subject to shrinkage in water will lose their tendency to shrink when laterally constrained by some system of porous constraint. Moreover, the firmer and more uniform the system of lateral constraint is, the less likely that shrinkage will occur.
Date created: 3/6/96
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