Preparation and surface properties of cashmere guard hair powders

Cashmere guard hair, a by-product from the cashmere dehairing industry is used for low value applications because the guard hairs are not suitable for spinning as they are coarse, contain large medullation and lack crimp or curvature. To find new uses in high value-added applications, cashmere guard hairs were milled into fine particles using the processing sequence Chopping → Attritor milling → Spray Drying → Air Jet milling. The guard hairs were partially hydrolysed with hydrochloric acid which increased the pulverisation rate due to the deterioration in mechanical properties. The volume median particle size d(0.5) was reduced from 2.328 μm, for untreated cashmere guard hair powder to 0.461 μm for powder from the acid hydrolysed guard hairs. FTIR and XPS studies revealed the breakdown of the cashmere guard hair cuticle cells and the exposure of the cortex on the powder surface along with the oxidation of the cashmere guard hair during milling.

Cashmere guard hair, a waste by-product from the cashmere dehairing industry, has been milled into fine particles that may have high value added applications.Figure optionsDownload as PowerPoint slideHighlights
► First time report on milling of cashmere guard hair for value added applications.
► Increased pulverisation rate during attritor milling by partial acid hydrolysis.
► Fine particles were achieved by air jet milling by breaking down aggregates.
► Acid treatment assisted air jet milling in achieving fine particles.
► Milling disintegrated surface cuticle cells and oxidised the particle surface.