Unique Properties and Applications of Tussah Silk

Tussah silk, a natural fiber derived from tussah silkworms, stands out with its distinct characteristics and versatile applications in the textile industry and beyond. This article delves into the morphology, composition, properties, and uses of this unique silk fiber.

1. Tussah Silk Morphology: A Microscopic View

Tussah silk, unlike the more common mulberry silk, is typically a light yellow to brownish color. Under a microscope, the raw silk is revealed to consist of two flattened fibers. These fibers have a longer diameter of approximately 65 microns and a shorter diameter of 12 microns. When examined using electron microscopy, these flattened fibers are seen to be comprised of numerous fiber bundles. These bundles, with a diameter between 0.75 and 0.96 microns, are separated by spaces of 0.53 to 0.60 microns. Tiny longitudinal lines are visible along the fiber’s long axis, indicating finer fiber particles. Notably, the fiber bundles contain numerous voids. The sericin particles on the fiber surface are small and wavy, adhering well to the fiber.

2. Tussah Silk Composition: A Chemical Breakdown

Tussah silk mainly consists of silk fibroin and sericin, both of which are proteins belonging to the fibroin family, and when hydrolyzed, form α-amino acids. The typical composition of Tussah silk is as follows:

The primary elemental makeup includes carbon, hydrogen, oxygen, and nitrogen, with sericin also containing traces of sulfur. Silk fibroin is predominantly composed of 18 amino acids, with the highest concentrations of alanine (50.5%), glycine (23.6%), serine (11.3%), and tyrosine (8.8%). Sericin, on the other hand, consists of 15 different amino acids, notably rich in serine (19.68%), aspartic and glutamic acid (19.06%), arginine (11.16%), and threonine (10.24%), with less glycine (8.04%).

3. Tussah Silk Characteristics: Distinct Advantages

Tussah silk exhibits a range of unique characteristics that set it apart from other natural fibers, making it well-suited for diverse applications. These characteristics are:

• Strength and Elongation: Tussah silk possesses considerable strength, measuring 3.41 to 3.55g in both dry and wet conditions. Its elongation ranges from 27.5 to 51.0%. These values are higher than both mulberry silk and wool. This superior strength and elongation contribute to the durability of textiles made from Tussah silk, making it ideal for clothing that endures repeated washing.
• Elasticity and Texture: Even after being wet and dried, Tussah silk retains its curled and wavy nature, which is advantageous for short fiber applications. This texture gives complex fiber blends and interweaves more elasticity.
• Insulation: Tussah silk is an excellent insulator with a dry voltage resistance of 7 to 8 kV. These properties make it suitable for protective insulating apparel.
• UV Resistance: Its flat shape and small pores enable it to absorb ultraviolet rays, making it resistant to sunlight and reducing brittleness.
• Chemical Resistance: Tussah silk shows greater resistance to acids and alkalis. For instance, immersion in concentrated nitric acid for 30 minutes results in only a 14.3% loss, while immersion in sodium hydroxide or concentrated sulfuric acid for 24 hours results in a 29.4% loss. This chemical resistance makes it ideal for chemical work attire.

4. Main Applications of Tussah Silk

Due to its advantageous physical and chemical properties, Tussah silk is employed across various sectors:

In summary, Tussah silk stands out as a valuable natural fiber with distinctive characteristics that make it suitable for a wide array of applications, from high-end fashion to industrial protection. Its combination of strength, elasticity, insulation, and chemical resistance makes it a versatile and indispensable material in the textile industry.