| Abstract: | Stress/strain properties of PTFE skived film over a temperature range of +25 °C to ?80 °C and the problem of notch effect Chemical plant under severe corrosive stress can be protected with “made-to-measure” liners welded up from PTFE skived film. For correct manufacture, handling and use of these chemical plant linings, a thorough knowledge of the semi-finished product and particularly of its load/deformation properties over a wide temperature range is required. The present paper deals with questions of strength and ductility and with the problem of notch effect at temperatures below + 25 °C. It is based on tensile tests carried out on PTFE skived film. Defined punched and cut notches were used to obtain information on notch sensitivity below room temperature. As the tests relate to two very different skived films, the reasons for these differences are analysed. The part played by the degree of crystallinity in determining many property differences is examined more closely with special reference to its effect on ultimate tensile strength, ductility and notch sensitivity. The aim of this study is not to determine material constants for PTFE but to identify tendencies in the behaviour of the semi-finished product, PTFE skived film, and so to gain useful information for its use in chemical plant lining. |
