The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 21, 2004
Filed:
Mar. 11, 2002
Applicant:
Inventor:
Kari Kirjavainen, Tampere, FI;
Assignee:
Conenor Oy, Espoo, FI;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B29C 4/420 ; B29C 4/450 ; B29C 4/456 ;
U.S. Cl.
CPC ...
B29C 4/420 ; B29C 4/450 ; B29C 4/456 ;
Abstract
A method and an apparatus for making a plastic film, and to a plastic film wherein the method includes extruding a film from plastic material by an extruder and orientating the film after extrusion. Material is mixed into the plastic so that when the plastic film is stretched, cavitation bubbles are formed in the material particles mixed into the plastic. After orientation, gas is arranged to act on the plastic film under high pressure so that the gas diffuses in the cavitation bubbles and causes overpressure in them. Thus it is possible to make a thin foamed film with a foaming degree of over 70%.