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. 16, 1997
Filed:
Jul. 08, 1996
Tomozi Mizutani, Yatsushiro, JP;
Katsuyuki Yokota, Yatsushiro, JP;
Masahobu Arita, Yatsushiro, JP;
Hisashi Kojyou, Yatsushiro, JP;
Kohjin Co., Ltd., Tokyo, JP;
Abstract
Apparatus for cooling a tubular thin film of thermoplastic resin in a melted state is described. The apparatus is capable of cooling the thin film from both the inside and the outside thereof while setting its diameter by interposing the film between the mandrel and an external circular coolant storage tank. The mandrel has a cylindrical shape and is connected with the lower side of a circular-shaped extruding die wherein the film is extruded downward from a circular slit in the die. The mandrel includes an air-injecting nozzle for injecting compressed air that maintains the shape of an upper bubble part of the thin film formed between the die and the mandrel. A coolant injecting nozzle which can inject the coolant toward the inner surface of the thin film is provided, the coolant injecting nozzle being formed into a single stage of circular slit or two or more stages of circular slits. Also provided is a ring for setting the diameter of the tubular thin film, a discharge port positioned in a side face of the mandrel for discharging the coolant used for cooling into the mandrel, and a seal ring for sealing the coolant in such a manner as to press the thin film, wherein the coolant can be obliquely injected, either downward or upward. The mandrel is useful for rapidly cooling the tubular thin film in a stable manner.