Patent · US Expired

Filter exchange device for an extrusion molding machine

US4880374A · kind A · utility

6Cited by
10References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 20, 1988
Grant dateNov 14, 1989
Priority date
Expiry dateMay 20, 2008

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29C48/693
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

A filter exchange device in a molten resin passage in an extrusion molding machine, which includes at least one filter casing for airtightly enclosing a spare filter and having port means for exhausting air out of the filter casing and filling the interior thereof with a gas inactive to molten resin. Fish eyes contained in the molded product after filter exchange reduced in number.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.