GB697883A - Method and apparatus for dicing sheet material - Google Patents

Abstract

697,883. Cutting plastic sheet material into granules. UNION CARBIDE & CARBON CORPORATION. Aug. 31, 1951 [Sept. 9, 1950], No. 20639/51. Class 87 (ii) [Also in Group II] Plastic sheet material, particularly of an elastic nature, is comminuted by progressively cutting it into individual particles of approximately equal size and shape along transversely spaced longitudinal rows so as to leave continuous longitudinal slots separated from each other by ribbons of the plastic sheet and then cutting the ribbons into further particles of a size and shape similar to the first by a succession of transverse cuts. A first rotary cutter 30 has evenly serrated teeth 20 spaced apart axially, e.g. by keying serrated discs on a shaft 32 and separating them by spacers, and the cutter teeth pass through slots 22 in a bed knife 24. The particles cut by these serrated discs fall into a hopper 43, and as the teeth pass through the slots the sheet is pulled forward as it is cut into individual particles and ribbons. Uniform feed is provided by squeeze type rolls 28. A second rotary cutter comprises transverse blades 26 which coact with a bed knife 25 to shear off the ends of the ribbons and so form other particles which also fall into the hopper 43. As the ribbons of material progress from the first cutter they are stripped from between the discs by fingers 42 extending from the second cutter bed knife. The cutter 30 initially cuts its own slots in the bed knife 24, which is adjustable to take up wear. The discs 30 are cooled by air from a perforated pipe 31 to prevent adherence of the particles.