Method of and apparatus for manufacturing biaxially oriented film
US4978484A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 1989 |
| Grant date | Dec 18, 1990 |
| Priority date | — |
| Expiry date | Mar 30, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2948/92923
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The present invention relates to a method of and an apparatus for manufacturing biaxially oriented film. A tubular original film which has been extruded by an extruding die is biaxially oriented by heat and air injected to the inside portion thereof being conveyed to nip rolls each having an individual circumferential speed. The temperature of heat to be applied to the film is controlled on the basis of the detected film thickness for the purpose of obtaining a uniform film thickness distribution. Furthermore, the film can be made uniform by adjusting the outer diameter of the bubble-shaped oriented film by adjusting the distance between two sets of nip rolls on the basis of the measured width of the film. In addition, when the thus-oriented film is subjected to a heat treatment, temperature of heat is arranged to be a predetermined temperature as to prevent adhesion of the films.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.