| 摘要 |
998,400. Moulding mats &c. VALENTINIGOMMA S.p.A. Jan. 9, 1964 [Jan. 11, 1963], No. 1018/64. Heading B5A. A sheet of rubber, or like vulcanizable elastomeric material, provided on one face with projections, the tips 12 of which differ in properties from the rest of the sheet, is formed by interposing an apertured plate 9 between an unvulcanized base sheet 13 and a top sheet 12, applying pressure to sheet 12 whilst firmly backing sheet 13 so that material from each sheet flows into contact through the apertures. The sheets are heated to bond and vulcanize them when sheet 12 has been sheared around the edges of the apertures. In an embodiment shown in Fig. 7 the sheet 12, the plate 9 and the sheet 13 are placed between a recessed mould 5 and a cover plate 11 and subjected to pressure between the platens of a press. The lands between the recesses 8 are aligned with and are slightly bigger than the apertures 10 so that a high shearing force is experienced by the material between the peripheries of the lands and the apertures. The sheared off material 12a is accommodated by the recesses 8, the assembly being heated when the position shown in Fig. 7 has been reached. |
