GB549712A - Improvements in or relating to shredding apparatus and methods of shredding fibrous material - Google Patents

Abstract

549,712. Grinding, crushing etc.; preparing cellulosic pulp. BRITISH CELLOPHANE, Ltd. May 27, 1941, No. 6804. Convention date, June 1, 1940. [Class 59] [Also in Group VIII] A sheet or slab 17 of alkali cellulose is fed through a pivoted guide 21 to two shredding rollers 13, 15 rotating in the same direction, the rollers being covered over their entire circumferential surfaces with teeth or spikes. The rollers may rotate at the same speed, in which case the sheet is fed at an angle as shown, so that the roller 13 engages a greater surface of the sheet than the roller 15, the sheet being thus fed into the bite. Alternatively, the roller 13 may rotate at a higher speed than the roller 15, in which case the sheet is preferably fed horizontally, the rollers being driven independently of one another and one of them being connected to a variable speed motor. The angle of feed may be varied by tilting the guide 21. An auxiliary roller 19 may rotate in the same or opposite direction from that of the rollers 13, 15, and at the same or a different speed: it may be as large or larger than the rollers 13, 15. The rollers 13, 15 may be of different dimensions. The teeth may be formed by positioning " garnett wire " (a saw-toothed band) in a spiral groove 43 or in circular grooves on the rollers and securing the band therein as by welding or soldering. Sections of two different kinds of garnett wire, 41 and 41a, are shown. A curtain 29, hanging in the hopper 27, may be shaken by means of a pivoted handle 31 to dislodge lumps of (moist) shredded alkali cellulose.