Determining Raw Cashmere Fibre Micron Profiles in Scoured Bales
Determining raw cashmere fibre micron profiles in scoured bales requires core sampling, lipid extraction, and truncated bimodal histogram distribution analysis.
Radial Swelling
Cross Sectional Expansion
Fibre dimensional change occurs when moisture absorption alters the physical boundaries of a textile filament. This radial swelling describes the percentage increase in fibre diameter or cross-sectional area as the material transitions from dry to wet. It is far more pronounced than longitudinal swelling in natural fibres.
Moisture Absorption
Cotton and viscose fibres absorb water readily, causing their internal structure to expand outward. The radial swelling of viscose can reach up to forty percent of its dry diameter, whereas polyester exhibits almost no dimensional change. Knowing these values helps yarn spinners select appropriate fibre blends for activewear and outerwear.
Fabric Density
When fibres within a tightly woven fabric expand, they reduce the space between the yarns and block the passage of air or water. The radial swelling of the individual threads increases the crimp of the crossing threads, which forces the fabric to thicken and shrink in length and width. This mechanism is the basis for self-sealing weather-resistant cotton canvases.
Yarn Behavior
High levels of swelling increase the pressure between fibres within a spun yarn, which can alter the yarn twist and friction. Spinning mills must calculate the consequences of radial swelling to prevent yarn breakage during wet processing and dyeing. In many woven goods, this expansion causes a measurable increase in fabric stiffness that must be managed with softeners during the final finishing stage.
The alteration can also affect the dye uptake because the denser fibre structure slows the diffusion of dye molecules.