Method of manufacturing a lining of polytetraflouroethylene (PTFE) for an expansion joint or similar flexible couplings, a PTFE lining and a tool for use in connection therewith

摘要

The invention concerns a method of manufacturing an internal lining of polytetraflouroethylene (PTFE) for an elastomer expansion joint or similar flexible couplings, whereby one or more unsintered tapes of PTFE or a PTFE-based material is/are wound around a rotary-symmetrical, non-cylindrical, positive forming tool whereby the tapes form a lining comprising a number of PTFE layers in a form which essentially corresponds to the desired internal shape of the elastomer expansion joint or a similar flexible coupling member, whereafter the lining is sintered and subsequently removed from the form by collapsing the self-locking shell of the forming tool by removing at least one retention member of the forming tool. The invention also relates to a forming tool for use in connection with the method. Hereby, it is possible to manufacture the lining in any kind of rotary-symmetrical shape. The form removal after the sintering process takes place by taking the forming tool apart. According to the invention, it is not necessary to carry out a mechanical deformation of the PTFE material which means that by using a method according to the invention, a more stable lining in any rotary-symmetric shape and with significantly improved chemical barrier properties may be obtained.