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.
Cuticle Scale Edge Height
Microscopic Measurement
Physical surface measurements of animal hair fibers determine their tactile characteristics and processing behavior in spinning mills. The cuticle scale edge height represents the distance that scale margins project outward from the fiber shaft of wool or specialty hair. This dimension is measured in nanometers using advanced imaging techniques such as atomic force microscopy or high resolution scanning electron microscopy.
Because scales always point toward the fiber tip, their protruding edges create an asymmetrical surface texture.
Frictional Behavior
Differential friction arises from these scale projections, causing the fiber to move more easily in the root-ward direction than in the tip-ward direction. A greater cuticle scale edge height amplifies this directional friction effect, which directly influences the hand and softness of the finished fabric. Coarser wools with larger heights feel pricklier to the touch, while fine merino or cashmere with lower scale profiles feel exceptionally smooth.
Consequently, spinners monitor this characteristic when sourcing raw fleece for high end apparel.
Processing Effect
Felting and shrinkage in wool garments are driven by this directional friction as fibers entangle under the influence of moisture, heat, and mechanical agitation. When the cuticle scale edge height is pronounced, the fibers lock together more tightly during washing, causing permanent shrinkage. Chemical treatments, such as chlorination or polymer application, are often deployed in the finishing mill to reduce this height or mask the scale edges entirely, producing machine washable wool products that maintain their dimensions.
Felt Analysis
Quality assessments of processed wool use scale measurements to confirm that anti-felting treatments have been applied uniformly. If the cuticle scale edge height remains unaltered after chemical processing, the treated lot is rejected due to the risk of excessive shrinkage in subsequent wet processes.