Patent · US Expired

Air cooling ring for plastic film with independent lubricating air for film guide surface

US4145177A · kind A · utility

21Cited by
10References
11Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 12, 1977
Grant dateMar 20, 1979
Priority date
Expiry dateDec 12, 1997

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29C48/912
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

Air ring for cooling a hot extruding tube of plastic film in which a lubricating air bleed port communicates with air from the air ring plenum independent of the cooling air flow path. The bleed port communicates with a bleeded air passage that extends to an annular lubricating air outlet positioned in advance of a guide surface that precedes the cooling air outlet. In an exterior air ring a valve arrangement limits the bleeded flow to the minimum desired.

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