Patent GB-1339935-A (GB)
Title: Method of forming a coated roller and apparatus therefor
IPC: B29C70/84
Filed: 1971-09-18
Abstract: 1339935 Coated roller ROYLAND ENTERPRISES Inc 18 Sept 1971 43623/71 Headings B2E and B2L [Also in Division B5] A coated roller is produced by applying a layer of coating material to the inner surface of a tubular sleeve shaped lamina formed of a synthetic resinous release material, positioning a roller-shaped body of circular crosssection within the coated tubular sleeve in a co-axial relationship, with the applied layer of coating material adjacent the outer surface of the roller body, effecting radial movement between the coated lamina and the rollershaped body by compressing the layer of coating material between the lamina and the roller outer surface, bonding the coating material layer to the roller by the compressing step, and removing the releasable lamina from the roller to provide the coated roller. As shown in Fig. 2 the sleeve 16 having a layer 13 of elastomeric coating material on its inner surface 17 is positioned within a mould M. The mould is detachably mounted on an extruder E. The mould M includes a tubular casing 31 having an inner diameter for accommodating sleeve 17 and arranged to be closed at each end of the screw-threaded connection by a pair of closure members 32, 33. The closure members 32, 33 include end caps 34, 36 and plug members 37, 38 having annular recesses 39, 41 respectively for accommodating the ends of the tubular sleeve 16. Plug member 38 is provided with a recess 42 for accommodating the end 11A of the cord 11 and plug member 37 is provided with a central bore 43 for accommodating the end 11B of the core 11 and a guide member 44. Plug members 37, 38 are also provided with ports 46, 47. Mould M is arranged to be mounted on the extruder E which includes lugs 48 receivable within slots 49 in an adaptor 51 secured by a screw-thread connection to the plate 52 of the extruder E. The adaptor 51 includes a central passage 52 having a tapered portion 53a and a straight portion 53b for conducting elastomeric material flowing in the direction of the arrow 1 from the extruder E into the mould M to fill the cavity 54 defined by the core 11 and the layer 13 of coating material on the sleeve. An elastomeric material such as silicone rubber is introduced into the mould cavity 54 to provide a rubber layer 12 which in combination with a core 11 forming a body having an outer surface 12a to be coated with the layer 13 of elastomeric coating material. The pressure of the material forming the silicone rubber layer 12 compresses layer 13 between the sleeve 16 and body formed by the core 11 and layer 12 thereby bonding permanently the layer 13 to the outer surface 12a of the silicone rubber layer 12. The rubber layer 12 is then vulcanised by removing the mould M from the extruder adaptor 51 and positioning the mould in a suitable vulcanising apparatus. Alternatively the rubber layer 12 and outer rubber layer 13 may vulcanise at room temperature. The assembly is then removed from the mould M and the sleeve 16 removed by a peeling operation. In another embodiment the sleeve 16 is heatshrunk so as to compress the layer 13 of elastomer between the sleeve 16 and the outer surface of a core thereby permanently bonding the layer to the core. As shown in Fig. 1 the layer 13 of elastomeric material is applied to the inner surface 17 of the tubular sleeve 16 of release material by spraying. Sleeve 16 is positioned within tubular mould 19 rotatably supported by bearings 21, 22. End caps 23, 24 having central bores 26, 27 within the ends of sleeve 16 define the ends of layer 13. A tube 28 provided with radial openings 29 is positioned within the bores 26, 27 of the end caps, one end 28a being closed and the other 28b communicating with a source of elastomeric material. Tubular mould 19 is rotated whilst elastomeric material is introduced into tube 28.