The density of silk fiber varies depending on whether it still contains sericin, a protein gum coating, or if it has been degummed.
Silk fiber density is approximately 1300–1400 kg/m³. More specifically, its density ranges from 1320–1400 kg/m³ with sericin present and 1300–1380 kg/m³ without sericin.
Understanding Silk Density
The density of a material is a measure of its mass per unit volume. For silk fiber, this property is influenced by its composition, particularly the presence or absence of sericin.
Silk yarn is primarily composed of two proteins:
- Fibroin: This is the structural protein forming the core filament, accounting for about 70-80% of the total weight.
- Sericin: This sticky, gummy protein coats the fibroin filaments, binding them together. It makes up about 20-30% of the raw silk weight.
The process of removing sericin is called degumming. Degummed silk, often referred to as boiled-off silk, is softer and has a different texture and luster compared to raw silk. As the reference indicates, removing the denser sericin slightly reduces the overall density of the fiber.
Here's a breakdown of the density ranges:
| Condition | Density (kg/m³) |
|---|---|
| With Sericin | 1320–1400 |
| Without Sericin | 1300–1380 |
This variation highlights how processing can affect the physical properties of natural fibers. Understanding the density is important for various applications, including textile manufacturing, material science, and potentially assessing the weight and volume requirements for silk products.
