| 摘要 |
<p>1,109,508. Polytetrafluoroethylene tape; seaming non-metallic sheet material. IMPERIAL CHEMICAL INDUSTRIES Ltd. 17 Aug., 1965 [4 Sept., 1964], No. 36311/64. Headings B5A, B5B and B5K. A process for producing wide tape of unsintered P.T.F.E. (polytetrafluoroethylene) comprises interlocking positively in a row, narrower sheets of unsintered lubricated P.T.F.E. to form a strip which is rolled in a direction parallel to forming the strip from the individual sheets under a pressure sufficient substantially to obliterate the interface between each sheet of the strip. The term " positively interlocking " means that the sheets are formed and related so that they do not part from each other in the rolling operation, as for example, shown in Fig. 2. The individual sheets may be derived from tubular film of an appropriate cross-section (see Fig. 3, not shown) which has been slit into a flat sheet, or by rolling flat a rod of P.T.F.E. Calenders are suitably used for the rolling processes. The rolled tape may subsequently be sintered.</p> |
