METHOD FOR MANUFACTURING PREFORM

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a preform which has a low extrusion pressure even at a high reduction ratio and is less likely to cause molding failure.SOLUTION: A method for manufacturing a preform includes the steps of: mixing a polytetrafluoroethylene fine powder with a paste extrusion auxiliary agent to obtain a mixture; leaving the mixture under a positive or negative pressure; returning the mixture to normal pressure to obtain a polytetrafluoroethylene paste; and preforming the obtained polytetrafluoroethylene paste.SELECTED DRAWING: None