Patent ID: 6357083
Filing Date: 2002-03-19
Classification: D01B

Abstract:
A method of producing fibers from plant material, the method comprising:stripping woody material from fibers of the plant material to produce decorticated plant material at a first level of fiber purity; providing a plant material scraping area defined by cooperating spikes on a cylinder and associated concave member arranged in a set; feeding the decorticated plant material at the first level of fiber purity to the cylinder and concave member set; rotating the cylinder with the spikes thereon passing the spikes on the concave member with lateral spacing therebetween; carrying the decorticated plant material with the spikes on the cylinder to the scraping area by rotation of the cylinder; scraping woody portions of the plant material from the fibers as the plant material engages spikes on the concave member in the scraping area to minimize shortening of the fibers; producing fibers at a higher level of purity than the first level after scraping and which are at a length that is only slightly shorter than the fibers fed to the scraping area; arranging the spikes on the cylinder and concave member in circumferentially spaced axial rows with spikes in adjacent rows having spikes that are axially offset from each other, and causing the plant material to undergo a back and forth scraping action as the cylinder spikes carry plant material to the scraping area with the plant material successively engaging offset concave member spikes in different rows on the concave member on either side of a cylinder spike.