- Observation method
Polyester is a kind of chemical fiber. Its surface is smoother than cotton and has a larger reflective surface. Therefore, the surface of all polyester cloth is smooth and has a luster of chemical fiber. The yarn of polyester-cotton blended cloth produced now is made of polyester staple fiber and cotton. One of the purposes is to make this kind of polyester-cotton cloth have a cotton-like appearance, and it is difficult to judge whether it is true or not. If it is polyester cotton grey cloth, the more cotton seeds on the cloth surface and the yellow color, the higher the cotton composition.
- Hand touch method
Polyester cloth has a cool, smooth, straight, and cold feeling, while the cotton cloth has a soft, easy to fold, and warm feeling, so it can be directly distinguished by hand touch.
- Calculate the composition proportion according to the specification
If the fabric is warp polyester weft cotton or warp cotton weft polyester, the theoretical proportion of polyester-cotton composition can be calculated through the formula. For example: 30 * 200D / 120 * 60 twill cloth, the number of pieces converted from 200D to D is 5315 / 200 = 26.6s
Theoretical gram weight of cloth = warp weight + weft weight
=0.1 * (warp density / 2.54) * (583.1 / warp count)
+0.1 * (weft density / 2.54) * (590.5 / weft count)
=144.3 g / m2
It can be concluded that the cotton content = 91.8 / 144.3 = 63.6%
Similarly, this method can be extended to other shuttle fabrics with different warp and weft yarn materials.