Analysis of Cloth Sample

Analysis of cloth sample: On analysis a sample of cloth made from cotton, rayon, silk or flax with view of its reproduction produced thus: 1. Record whether a fabric is in grey or the finished state. 2. Determine which threads constitute warp & which weft. 3. If in grey, test for the presence of size material by staining with iodine, when the starch in the size warp turns deep blue in color, the weft being unaffected. 4. Examine for direction of spinning twist in the yarns & also if either set of threads is two-fold yarn. If crepe yarns have been used, it may be necessary to test for amount of twist present. 5. Count the ends & picks per inch in the fabric. If more than 2 warps or wefts are used, find the number per inch of each yarn type used. 6. Test the yarns for regain i.e. how much longer they are out of the cloth than the length of the sample from which they were abstracted. By this means we can estimate the length in reed or length of each pick of weft. In weaving ordinary classes 10% of cotton goods warp regain between 4% & according to the structure, while the weft regain is usually about 5%. These figures apply to grey cloths only. In finished goods, the regain will differ according to the nature of the finished applied. Very often the length of the cloth is increased & its width reduced on finishing, hence the warp regain may be as low as 1% to 4% will probably be found in both warp & weft. 7. Test the yarns for counts of warp & weft (The count of the yarn is the number of length units required to weight on gain). In a grey sample the warp will probably be sized yarn & the count recorded will be sized count. This should be corrected by making a second test after thoroughly washing the fabric to remove all size & filling materials. If the sample is a bleached, dye or printed cloth, the counts of warp & weft will be affected counts test then made, allowing about 5% in bleached count=20s grey count: 38s bleached=36s grey count.