| 摘要 |
1459099 Finishing edges of non-metallic sheet material G H HEATH & SON (UK) Ltd 8 Nov 1974 [5 Dec 1973] 56271/73 Heading B5K [Also in Division B1] A filter cloth comprises a pair of confronting foraminous sheets 12 each having an aperture 14 therein, and there being a tubular section 18 extending between the apertures 14 and secured by heat bonding to the marginal zones of the sheets 12 which bound the apertures 14 such that the sheets 12 are secured together in spaced relation, the sheets 12 and/or the section 18 being composed of a thermoplastic material. In the embodiment shown, the sheets 12 are woven from multifilament nylon strands and polyvinyl chloride reinforcing annuli 16 are first heat bonded to the outward faces of the sheets 12 and the section 18 of polyvinyl chloride is heat bonded at its ends to the annuli 16 preferably by high frequency welding. The section 18 may be made from a flat strip the ends of which are brought together and heat bonded. In a modification (not shown), the annuli 16 are integral with the tubular section and form flanges at each end thereof. In use, the sheets 12 are disposed one on each side of a filter press tray with their apertures 14 in registry with a centrally disposed aperture in the tray. |
