GB820325A - Extrusion machine and process - Google Patents

Abstract

820,325. Extrusion machines. MONSANTO CHEMICALS Ltd. May 13,. 1957 [June 21, 1956], No. 19218/56. Class 87(2). An extrusion machine comprises a beam having near each end a roller to press plastic material e.g. rubber chemicals mixed with polyisobutylene, through an orifice, the beam being freely mounted so that it may "rock" enabling the rollers to move towards and away from the orifice. Either the beam or the orifice may rotate. A rod 1, rigidly attached to a base 2, has a rotatably mounted cylinder 3 having a plate 5 and a plate 9, mounted on arms 8, the plates 5, 9 forming between them an annular opening bridged by a perforated plate or gauze 10 surrounded by an enclosing wall 13. The rod 1 has a fixed bar 24 having two posts 25 passing through and thus preventing rotation of a beam 14 having at each end a pivotally mounted frustro-conical roller 15. The rod 1 passes through the beam 14 and a fulcrum, under the adjustable action of a spring 22, forces the rollers 15 into contact with the perforated plate 10 whilst allowing the beam 14 to rock an amount controllable by nuts 26 on the posts 25. Guides 28, 29 for the plastic material are attached to the bar 24 and the rollers 15 have scrapers 17. In operation, the cylinder 3 is rotated, plastic material is fed on to the perforated plate 10 and, as rotation continues, is forced by the rollers 15 through the perforations to fall on to a tray 31 mounted on the cylinder 3. The strands may be cut into pellets by stationary knives, or, if the beam rotates and the perforated plate is stationary, by rotating knives. Specification 736,969 is referred to