Patent ID: 6083112
Filing Date: 2000-07-04
Classification: A63D,B29C,B29K,B29L

Abstract:
A method for manufacturing a plastic pin comprising a porous core and a resilient envelope, said method comprising the steps of:a) blow-forming a completely closed envelope in a blowing mold;b) removing the envelope from the blowing mold;c) cooling the envelope to a temperature of 60.degree. C.-100.degree. C.;d) heating a plastic material to a temperature of 200.degree. C.-260.degree. C.;e) piercing a bottom of the envelope with an injection needle and injecting the heated plastic material containing an exothermic blowing agent into the envelope for forming the core, wherein an inner layer of the envelope is heated by the heated plastic material and thereby fuses with the plastic material of the core; andf) cooling the bottom of the envelope in order to solidify the plastic material at the bottom of the envelope so that no plastic material can exit when the injection needle is removed.