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US 4,115,048 AGranted
Apparatus for internally cooling a plastic tubular film bubble
AssigneeUnion Carbide Corporation
InventorsRichard Bernhard Alderfer, Gerald Harry Scheibner
Life of this patent
Estimating the term…
Abstract
An apparatus and method for internally cooling extruded tubular film produced from film-forming polymers such as polyethylene, polypropylene and the like.
Claims37
An apparatus for manufacturing film from thermoplastic resinous film forming materials which comprises in cooperating combination:
- (a) a tube die adapted to extrude a film tube;
- (b) flattening means positioned a distance from the die for flattening the extruded tube;
- (c) a diffuser disposed on the discharge side of the die in the space enveloped by the extruded film tube, said diffuser having a gaseous coolant inlet disposed in the inlet portion of the diffuser, and said diffuser further having means to deliver from its peripheral surface a gaseous coolant to the interior surface of the extruded film tube;
- (d) film slitting means disposed between said inlet portion of said diffuser and said tube die for continuously slitting the extruded film to provide at least one slitted opening in the extruded film;
- (e) restrictor means associated with the diffuser defining a primary zone and a secondary zone of the extruded film and being adapted to maintain a pressure differential between the primary and secondary zone;
- and
- (f) means operatively associated with said gaseous coolant inlet for communicating gaseous coolant through the slitted opening to the gaseous coolant inlet whereby gaseous coolant introduced to the diffuser through the gaseous coolant inlet continuously passes through the diffuser into the primary and secondary zones and into contact with the interior surface of the tube and is continuously withdrawn through said slitted opening.
4 more elements
Apparatus for manufacturing film from thermoplastic resinous film forming materials which comprises in cooperating combination:
- (a) a tube die adapted to extrude a film tube;
- (b) flattening means positioned a distance from said die for flattening said extruded tube;
- (c) a diffuser disposed on the discharge side of said die in the space enveloped by said extruded film tube, said diffuser having a gaseous coolant inlet disposed in the inlet portion of said diffuser, and said diffuser further having means to deliver from its peripheral surface a gaseous coolant to the interior surface of said extruded film tube;
- (d) film slitting means disposed between said inlet portion of said diffuser and said tube die for continuously slitting said extruded film to provide at least one slitted opening in said extruded film;
- (e) restrictor means associated with said diffuser defining a primary zone and a secondary zone of said extruded film and being adapted to maintain a pressure differential between said primary and secondary zone;
- (f) means operatively associated with said gaseous coolant inlet for communicating gaseous coolant through said slitted opening to said gaseous coolant inlet whereby gaseous coolant introduced to said diffuser through said gaseous coolant inlet continuously passed through said diffuser into said primary and secondary zones and into contact with said tube and is continuously withdrawn through said slitted opening;
- and
- (g) means for improving film gauge uniformity including an internal air ring disposed about said diffuser in said primary zone and positioned proximate said tube die.
5 more elements
Apparatus for manufacturing film from thermoplastic resinous film forming materials which comprises in cooperating combination:
- (a) a tube die adapted to extrude a film tube;
- (b) flattening means positioned a distance from said die for flattening said extruded tube;
- (c) a diffuser disposed on the discharge side of said die in the space enveloped by said extruded film tube, said diffuser having a gaseous coolant inlet disposed in the inlet portion of said diffuser, and said diffuser having means to deliver from its peripheral surface a gaseous coolant to the interior surface of said extruded film tube, said means including circumferentially disposed areas defining openings on the outer surface of said diffuser;
- (d) film slitting means disposed between said inlet portion of said diffuser and said tube die for continuously slitting said extruded film including at least one slitter knife adapted to provide at least one slitted opening in said extruded film;
- (e) restrictor means assocated with said diffuser defining a primary zone and a secondary zone of said extruded film and being adapted to maintain a pressure differential between said primary and secondary zone;
- and
- (f) a communicating conduit operatively associated with said gaseous coolant inlet for communicating gaseous coolant through said slitted opening to said gaseous coolant inlet whereby gaseous coolant introduced to said diffuser through said gaseous coolant inlet continuously passes through said diffuser into said primary and secondary zone and into contact with said extruded tube and is continuously withdrawn through said slitted opening.
4 more elements
Dependencies are inferred from the claim text.