Silk is commonly known as silk, silk fabric is also sil […]
Silk is commonly known as silk, silk fabric is also silk fabric, mechanical 缫 is also known as factory silk, hand-made 称 is called earth. Silk silk factory from the silk factory is commonly known as raw silk. The raw silk is degummed and becomes a cooked silk. 1. The properties of raw silk are smooth, transparent, soft and elastic, and the gloss is soft and elegant. The fabrics will rub each other to produce a special silky sound. The cross section of the raw silk is in the form of a pair of approximately triangular (or approximately pomegranate seed). The density of the raw silk is 1.33 to 1.45 g/cm3, and the density of the cooked silk after degumming is 1.25 to 1.30 g/cm'. Raw silk has strong hygroscopicity and good air permeability.
The standard moisture regain rate is 11%. In the humid air with relative humidity of 100%, the maximum moisture regain rate can reach 36% to 39%, the length of raw silk after water absorption increases by 1.3% to 1.6%, and the cross section increases by about 19%. The raw silk has good strength and elongation, and the tensile strength at break is 3.0 to 3.5 dN/t. x, elongation at break is 15% - 25%. The hygroscopicity, strength and elongation of the raw silk are reduced after scouring and degumming. The initial modulus of silk is 45–90 dN/tex. Mulberry silk is poor in light resistance, yellowing, hard, brittle, and strong after sun exposure.
When the silk is dry, it is not conductive. It is a good insulator. In the relative humidity of 65%, the mass specific resistance can reach 10 plus 2g/cm. Therefore, in the production process, static electricity is easily generated due to friction, so the temperature and humidity of the workshop must be controlled. Or use static elimination measures. The silkworm has good thermal insulation performance, and the thermal conductivity is about 50-54 roW/(m'K), which is the smallest among natural fibers, so the silk fabric should be worn in winter and summer. Raw silk is stable to weak acid. However, it is not resistant to strong acid and will be hydrolyzed in a strong acid solution, especially at high temperatures. Raw silk has weak stability to alkali, and is significantly hydrolyzed in a strong alkali solution, even more at high temperatures.
The color absorption performance of mulberry silk is excellent (staining is usually carried out after scouring), acid dye, reactive dye, acid mordant dye, vat dye and direct dye are suitable, and can be selected according to requirements. In short, the performance of silk has been excellent in all aspects, and its excellent performance has been the target of all chemical fibers.