Extrusion process and product
View Patent ↗The present invention relates to the process of extruding melt drawing fluoropolymer onto conductor to form insulated conductor at a line speed of at least 533 m/min and having no more than 10 sparks and no more than 2 lumps/13.7 km of insulated conductor under conditions that comprise an adequate process window to allow for these results to be obtained at different conditions within the process window. The invention identifies the critical parameters for achieving this process window, namely melt flow rate of the fluoropolymer, preferably being 30±3 g/10 min, and the melt temperature of the extruding/melt-drawing step, preferably being 393° C.±6° C.
1. Tetrafluoroethylene/hexafluoropropylene copolymer having a melt flow rate of 30±3 g/10 min, said copolymer containing an amount of perfluoro(alkyl vinyl ether), wherein the alkyl contains from 1 to 5 carbon atoms effective for said copolymer to have an MIT flex life of at least about 4000 cycles.
2. The copolymer of claim 1 wherein said perfluoro(alkyl vinyl ether) is perfluoro(ethyl vinyl ether).
3. The copolymer of claim 1 capable of being extruded as insulation on wire at a line speed of at least about 1750 ft/min at a melt temperature in the range of 393° C.±6° C.
4. The copolymer of claim 3 wherein said melt temperature is in the range of 393° C.±4° C.