What are the scientific compounds of cultivated silk?
75% silk
23% seri in
2% fat/wax/mineral salts
What are the scientific compounds of wild (tussah) silk?
- silk is a protein composed of 15-18 amino acids depending on silk type
- The 3 most common amino acids are compact allowing high levels of crystallinity in the fibroin polymers (70-75% crystalline)
- many hydrogen bonds between polymers
- this means high strength and reasonable elongation of silk
What is silk protein called?
Fibroin
What is the general length of silk filament?
Up to 1.6km
- central 1km of silk is used as filament
- the waste at the ends is spun
What is the fineness of silk?
Very fine around 1 ,u
What is the tenacity of silk?
Strong, weaker when wet
What is the elongation of silk?
20-25% elongation
How good is silk’s elastic recovery?
Better than cotton, not as good ad wool
What is silk’ resilience like?
Very good, hard to crease and wrinkles tend to fall out
How is silk’s absorbency?
Very good, can hold 1/3 its weight in water without feeling wet
How does silk react with heat?
- can withstand heat at 140degrees
- decomposes quickly at 175degrees
- doesn’t burn easily, though when ignited smells like burning hair
How does silk react with chemicals?
- can be weighted by iron, tin salt solutions, etc.
- absorbs acid, damaged by alkali
- dyes well
How does silk react to light?
-can become damaged in prolong sunlight and oxygen (decomposes)
What is the cost of silk?
Expensive, similar to luxury hair fibres
How is silk normally processed?
- filaments normally processed in pure form
- staple silk can be spun into 100% pure silk yarns
- can also be blended with other fibres, cashmere, wool, etc.
What are silk’s unique selling points?
- Very fine and absorbent therefore comfortable next to skin
- is also very strong when not weighted with chemicals
- lovely drape qualities as a fabric
