Physicochemical properties of tussah silk
Tussah silk consists of two flat fibers with an obtuse triangle in cross section. The silk fibroin content is as high as about 85%. After repeated refining with soap base, the weight loss is only 10-11%.
Tussah silk contains more pigments, which are often light yellow or light brown. Some pigments are firmly combined with silk fibroin and are not easy to remove when bleaching.
Tussah silk is relatively thick, and the commonly used strands are all above 35D, so the fabric has high strength, and the wet state is higher than the dry state. It is durable, washable and durable, but it is easy to stretch after absorbing moisture. % shrinkage. At the same time, tussah silk will also curl, and its degree will vary with temperature. "Contraction" expresses two different states. Because the crimp gives the fiber a corrugated appearance, this corrugated appearance does not disappear after refining.
Tussah silk has strong heat resistance. When pressure-treated in high-temperature water, only part of the sericin is decomposed, and the silk fibroin will not be damaged due to heat resistance. Baking at 140°C for 30 minutes, the strength will gradually weaken, and the drying strength above 200°C will drop sharply.
Tussah silk has strong acid and alkali resistance and is relatively stable to oxidants such as hydrogen peroxide, but it is not stable enough under pressurized steam for a long time. It is precisely because tussah silk is not sensitive to chemical solution treatment that it brings many difficulties to the refining, bleaching and dyeing processes.
The oxidation effect of light on tussah silk is serious, making the fiber brittle and reducing its strength and elongation.
