Like all textile fibers, silk has its own physical and chemical properties which require to know for better processing in spinning, weaving, knitting, dyeing, printing as well as finishing. Here, I point out the physical and chemical properties of silk fiber.
Uses of Silk Fiber:
The silk fiber is a different type of textile fiber. When silk fiber has various uses in the textile and apparel manufacturing industry. In the first place, this fiber is popular all over the world for its valuable and outstanding appearance. It is also popular to make children’s wear, ladies’ wear, tie suits, and other applications.
Physical Properties of Silk Fiber:
There have a lot of physical properties of silk fiber. The following are the physical properties of silk fiber. They are-
Firstly, Color: The color of silk fiber could be yellow, brown, green, or grey.
Secondly, Length: Silk fiber length varies from 400 to 700 meters.
Thirdly, Tensile Strength: Silk is a strong fiber and it has a tenacity of 3.5 – 5 gm/den. Also, moisture affects the strength of silk when the wet strength of silk is 75 – 85%, which is higher than dry strength.
Then, Cross Section: Its cross-section is triangular.
After that, Elongation at Break: Its extensibility is 15% when at the break. In fact, its recovery from the stretch is 90% when the extension is up to 2%.
Therefore, Fineness: It is a very fine fiber although its fineness varies from 11 to 12 microns.
Identically, Elastic Recovery: Elastic recovery property of silk fiber is moderate.
Next, Specific Gravity: Specific gravity is 1.25 to 1.34.
Therefore, Moisture Regain (MR%): Standard moisture regain is 11% but it can absorb up to 35%.
Effect of Heat: Silk will withstand higher temperatures than wool. When it will remain unaffected for prolonged periods at 1400C but it decomposes at 1750C.
Flammability: Silk fiber burn slowly when in contact with flame.
Abrasion Resistance: Its abrasion resistance is eventually good.
Effect of Sun Light: Sunlight tends to encourage the decomposition of silk eventually by atmospheric oxygen.
Lastly, Luster: Silk fiber has bright luster properties.
Chemical Properties of Silk Fiber:
The following are the chemical properties of the silk fiber. They are:-
Firstly, Effect of Acids: The Fibroin of silk can be decomposed by strong acids into its constituent amino acids, and in moderate concentration, acids cause a contraction in silk. besides, dilute acids do not attack silk under mild conditions.
Secondly, Effects of Alkalis: Alkalis causes less damage to silk fiber than wool. Weak alkalis such as soap, borax, and ammonia cause little appreciable damage. Finally, it dissolves in solutions of concentrated caustic alkalis.
Thirdly, Effect of Organic Solvent: Silk is insoluble in the dry-cleaning solvents in common use.
After that, Effects of Insects: Insect does not affect silk markedly.
Lastly, Effect of Mildew: Mildew affects slightly this silk fiber.
Surely, the above physical and chemical properties of silk fiber will help us to be careful about the processing of silk in the different stages of processing from spinning to garment making. Moreover, day by day the use of silk products is increasing rapidly.