Why does Tussah silk fabric have higher durability and strength than ordinary silk?

Tussah silk fabric has higher durability and strength compared to ordinary silk (mulberry silk) due to several factors related to its production process and the characteristics of the silkworms that produce it:

1. Diet and Lifestyle of Silkworms: Tussah silk is produced by wild silkworms (Antheraea species) that feed on a variety of natural, wild tree leaves and plants. In contrast, mulberry silk is produced by domesticated silkworms (Bombyx mori) that are fed a controlled diet of mulberry leaves. The wild silkworms' diet includes tougher and more diverse plant materials, leading to the development of stronger and more resilient silk fibers.

2. Natural Environment: Wild silkworms live in their natural habitat and face a more challenging environment compared to domesticated silkworms. The exposure to natural elements and predators may result in the production of silk with higher strength to ensure the survival of the cocoon and the pupa within it.

3. Thicker and Coarser Fibers: Tussah silk fibers are generally thicker and coarser compared to mulberry silk fibers. The thicker fibers contribute to higher tensile strength and increased durability of the fabric.

4. Less Sericin Removal: Sericin is a protein that covers silk fibers and acts as a natural gum or glue. In the case of tussah silk, the sericin is not removed as thoroughly during the production process, leaving some of it intact in the fibers. This partial retention of sericin enhances the silk's durability and gives it a slightly rougher texture.

5. Less Processing: Tussah silk undergoes less processing compared to mulberry silk. The wild silk is often hand-spun and hand-woven, maintaining the natural integrity of the fibers. This minimal processing helps preserve the silk's inherent strength.

6. Cross-Linking of Fibroin: Tussah silk fibers contain more cross-linking in their fibroin protein structure. These cross-links enhance the intermolecular forces between the fibers, resulting in increased strength and resistance to stretching.

Due to these factors, tussah silk fabric possesses a unique combination of natural texture, strength, and durability. It is especially valued for its rustic charm, eco-friendliness, and ability to provide clothing and textiles that can withstand wear and tear while maintaining their elegant appearance over time.