Collagen Peptide Fiber

How it works

Peptides Enter at the Spinning Stage, Changing the Nylon's Surface Character

The raw material comes from fish scales, whose main constituent is type I collagen. Acid–alkali treatment followed by enzymatic hydrolysis cuts the long collagen chains into lower-molecular-weight peptide fragments carrying polar functional groups — amine and carboxyl among them. What matters is when they are introduced. The peptides are added to the spinning dope during melt spinning of the polyamide, so they take shape with the filament and are distributed through its cross-section rather than deposited on the surface as a finish would be. Hydrogen bonding and intermolecular forces between the peptides' polar groups and the polyamide backbone hold them in the fibre matrix. Three physical changes follow. First, the hydrophilic groups raise the fibre's moisture regain — unmodified nylon 66 sits at roughly 4%, and peptide-modified fibre is higher, so the fibre itself holds more water. Second, surface polarity increases and the coefficient of friction drops, lowering the resistance felt against skin; this is the physical basis of the smoother hand. Third, the presence of both amine and carboxyl groups leaves the fibre weakly acidic, close to the pH of the skin surface.