Fiber Quality Parameters Influencing Fiber Breakage in Lint Cleaning: Frictional Characteristics of Fiber Assemblies

Saw-type lint cleaners reduce fiber length and increase short fiber content. In addition to commonly measure cotton fiber quality parameters such as strength and fineness, it is becoming clear that fiber friction influences lint cleaner efficiency. Static inter-fiber friction determines the cohesiveness of fiber clusters and the energy required to open them. Also, abrasive sliding friction between loose fiber assemblies and lint cleaner grid bars may cause fiber damage and breakage. In this study, we evaluated the frictional properties of forty-eight different cotton varieties and explored the relationships between the fiber friction and HVI fiber-property measurements. In general, the amount of energy dissipated within a loose fiber assembly during sliding depends on static inter-fiber frictional forces, fiber orientation, fiber crimp, and convolutions. In addition to empirical results on fiber friction, a theoretical model describing the real contact area of an assembly of randomly oriented fibers as a function normal applied force was developed.   The model takes into account various parameters such as number of fibers in the assembly, distribution of fiber cross-sectional shape, the degree of secondary cell wall thickness, and fiber length. The theoretical results were compared with experimental measurements.