Sunday, June 12, 2011

FURTHER WINDING TEST

         The winding may be tested further as follows . A two in wide length of adhesive tape such as is used by electricians for insulation ( or gummed paper or transparent cellulose adhesive tape ) is cut five ins . long. It is pressed longitudinally along the rod and pressed round the circumference to cover the winding completely. a sharp knife is then used to cut the winding along the length of the rod where the two edges of the tape meet .It is then a simple matter to strip the winding off from the rod as a sheet of parallel threads measuring two ins. by five ins.The sheet is placed face downwards upon a flat surface and ironed with a warm iron to complete firm adhesion to the tape .
         This pad or sheet is sufficiently stable to withstand wet treatments such as scouring stripping of sye re dyeing or testing with B D H Universal Indicator for variations in alkalinity or acidity or staining with ferro cyanide for iron content or for examination by ultra violet light for mineral oil stains . It is useful to employ this method in conjunction with the staining methods given in my other post .
This device may also be used to follow variations in length due to processing. A length of yarn is wrapped round the long axis the yarn is unwrapped and treated (e.g. by mercerisation ) dried and rewound under the same tension as originally used . Shrinkage will be indicated be the marked places forming a spiral on the rod and irregular shrinkage will show as irregularities in the spiral.
In practical works laboratory technique the use of the inspection board and inspection rod coupled with systematic examination of variations in the consecutive length of yarn obtained in the way described will solve a large percentage of the problems encountered.

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