Patent · US Expired

Apparatus for heat-trimming foam material

US4242074A · kind A · utility

17Cited by
5References
7Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 6, 1976
Grant dateDec 30, 1980
Priority date
Expiry dateDec 6, 1996

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29C51/32
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

A thermoplastic material, such as a sheet of polystyrene or polyethylene foam, is placed between a trim guide, which may be a die mold or press, and is in the form of at least two heat-conducting metal pieces, one of which is movable towards the other. The trim guide is pressure-operated to pressurize the material along the area to be trimmed. This may be an edge of a plastic sheet, the perimeter of an article produced from the material, or may be holes or slots to be cut in the material. A knife or other tool, heated to a temperature high enough to melt the material, is then moved along the trim guide. The knife vaporizes the pressurized material along the trim guide, which creates a definitive point at which melting or vaporization of the material stops. The trim guide is made from metal having high heat-conductivity, such as aluminum which has sufficient heat-conductivity to create a point at which melting, caused by the knife vaporizing the material, stops.

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