Abstract: A method for separating long, unwound items like fiber, fiber strands, yarn, etc. having a liquid chemical sizing on the surfaces into short lengths by chopping is disclosed. Improved chopping life is achieved by using blades, or at least blade edges of cemented tungsten carbide, and selecting the liquid chemical sizings having a pH of about 7 or greater to apply to the surfaces of the items being chopped. Also disclosed are blades having at least the sharp edges of the chopping blades coated with various materials including a material selected from a group consisting of tungsten carbide, titanium nitride, diamond like carbon, polycrystalline diamond, polycrystalline cubic boron nitride, cemented tungsten carbide, or mixture of two or more of these materials.

Abstract: A method and apparatus for chopping long unwound items like fiber, fiber strands, yarn, etc. having an idler roll for pressing the item(s) against a backup roll for pulling the item(s) into the chopper, the idler roll being an assembly allowing the idler roll to pivot around a pin inside the idler roll assembly to keep the surface of the idler roll in proper contact with the items being chopped.