Patent ID: 6565347
Filing Date: 2003-05-20
Classification: B29C

Abstract:
An extruder die head having at least one internal cylindrical mandrel and a cylindrical shell, which encloses concentrically said mandrel, an annular channel formed between said mandrel and said shell for emptying into a die slit, at least one line, which feeds a polymer melt into said annular channel in an area opposite said die slit,the improvement comprising: a ring having a coefficient of thermal expansion &ggr; and positioned between a part of an outer surface of said mandrel and a part of an inner surface of said shell, and in said area of said annular channel for sealing said area between said shell and said mandrel, said ring formed by a pipe piece shrunk into said shell, and said pipe piece having such coefficients of thermal expansion that a seat, which connects said mandrel to said shell and is located below said annular channel, becomes more impervious with heat.