GB333161A - Improvements in or relating to the manufacture of sheets from plastic material - Google Patents

Abstract

333,161. White, A. E., (Upson Co.). April 3, 1929. Processes; endless-chain machines.-Relates to the manufacture of sheets or wall boards from plastic or intumescent material as described in Specification 300,041, [Class 70, Indiarubber &c.], and consists in confining the material between heated platens to give it form, transferring it to an adjacent oven where it is hardened sufficiently to be acted upon by feeding-means and then passing the material to a second oven where the heat treatment is completed. As shown, a mixture containing sodium silicate and powdered dolomitic limestone is fed from a hopper 4, Fig. 1, between paper sheets X, Y which are fed from rolls 2, 3 and carry the material between heated platens 7, 8 past trimming devices 9, 10, Fig. 2, into an oven 11 where the material is hardened sufficiently to be acted upon by feed rolls 12, Fig. 3, placed beyond the oven. After passing the rolls 12, the material is severed into slabs by a cutting-device 13 and delivered by a ramp 14 to a roller conveyer 15 which carries the slabs through a processing or curing oven 18 disposed beneath the oven 11 and platens 7, 8. At the front end of the oven 18 the slabs are delivered to a conveyer 19 which carries the slabs again through the oven and delivers the finished product. In place of the paper liners X, Y temporary liners of metal or greased paper may be employed which liners may be endless or may be unwound from a roll in front of the platens and wound up on another roll at the end of the first oven. A modified machine is described wherein the curing oven is disposed above the hardening oven.