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. These coated blades can be used to separate items having both neutral, basic and acidic sizings thereon