| Expanded Polytetrafluoroethylene(EPTFE) has particular network structure and stable chemical property which make it useful for hazarded heard repairing. In recent years ,the requirement for it is increasing quickly. But the products we use are mainly imported. Its high price give the sick hard load. So, it抯 very important not only in theories but also in economical practice to produce EPTFE with good property in China. According to the multi-stretching theory, We have designed and produced a special machine for EPTFE membrane production which has been installed heating control device, oven, sample-fixed device and etc.. On the basis of success of multi- stretching machine, the results prove that it can be used for studying and preparing the EPTFE membrane.It can meet the demands of hazarded heart repairing. EPTFE membrane can be produced by mixing PTFE resin and liquid lubricant, then grinding, molding, calending,drying, stretching, sintering and quenching. The optimum conditions could be concluded as following: 1 Dispersion PTFE resin should be chosen from high MW PTFE; 2 Optimum composition was lOOg PTFE plus 20挆3Oml liquid lubricant; 3 The plate is produced by molding under 30?OMPa; 4 The plate is calended at 30~400C and folded for 4?-6 times; 5 The slice is dried at 80?00C; 6 The slice is stretched for 400% at 17000; 7 The slice is sintered at 36000 for 10~?0 mm; The heating rate was 60扖/h before 32700 and 200C/h after 32700; 8 The EPTFE membrane is quenched in air. The EPTFE membrane tensile strength is up to 7.76MPa, elongation at break is up to 94.61%, porosity is up to 68%, the size of pore is up to l.11?.44i?m. So, the complex property can catch up with the Gore-Tex membrane,but its price is much low than Gore-Tex membrane.The EPTFE membrane can be used for animal organism (such as rabbit and rat) repairing which has be proved by Shao Shao Run Hospital. The results show that the membrane has no toxicity and good compatibility with the organism of the sample animals.
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