Q: how do you determine the holding time of PTFE after heating?
Answer: is the process of insulation will reach the preform sintering temperature to maintain a certain time in the temperature of the "burn". The holding time depends on the sintering temperature, the thermal stability of raw materials and the parison wall thickness and other factors, but must ensure the quality of sintering (with parison into transparent or translucent for quasi) as the premise. The sintering temperature is high, the holding time can be shorter; the difference in thermal stability of raw materials, the holding time should be short, otherwise it will cause the decomposition of the plastic resin, surface light, foaming and cracks; for large thick wall plastic parts, in order to ensure the center thoroughly, holding time we should take longer. In production, the thermal stability of raw materials production of large and medium-sized plastic parts, the holding time is 5~10h, small pieces of plastic holding time is about 1H. The introduction of time according to the parison thickness selection, general 5~8mi N/mm.