Raw Cashmere Classing and Guard Hair Percentage Estimation
Raw cashmere value hinges on clean down yield and optical verification of residual coarse hair content below zero point five percent by mass.
Fiber Flexural Rigidity
Bending Resistance
Mechanical properties of textile materials govern their resistance to deformation during yarn processing and fabric manufacturing. The fiber flexural rigidity represents the resistance of a single fiber to bending forces, determined by its cross-sectional shape and polymer structure. This property influences the stiffness and drape of the final fabric, making it a critical parameter for product design.
Scientists calculate it from the fiber modulus and the moment of inertia of the fiber cross-section.
Structural Influence
Finer fibers exhibit lower bending resistance because their smaller diameters decrease the moment of inertia. For a given polymer type, the fiber flexural rigidity decreases with the fourth power of the fiber diameter, meaning even minor reductions in fiber thickness yield vastly softer yarns. Hollow fibers, on the other hand, maintain higher rigidity than solid ones of the same weight, which is useful for creating lightweight, bulky fabrics that resist crushing.
Spinning Behavior
Yarn manufacturing processes require careful selection of raw materials to avoid processing issues arising from high stiffness. When the fiber flexural rigidity is too high, the fibers resist being drafted and twisted, leading to hairy yarns with low strength. Conversely, fibers with low rigidity bend easily, allowing them to pack tightly during spinning to create strong, smooth yarns with minimal hairiness.
Spinners adjust machine settings and twist levels to accommodate the stiffness of the sourced stock.
Fabric Performance
Tactile characteristics of finished garments depend directly on these individual fiber behaviors. High fiber flexural rigidity translates into a crisp, firm hand, whereas low rigidity produces fabrics that are supple and drape well.