A process for making film from a narrow molecular weight distribution low density ethylene hydrocarbon copolymer, which process comprises extruding said copolymer through a die gap of greater than about 50 mils. The film exhibits an excellent balance of optical and mechanical properties.

Process for making film from low density ethylene hydrocarbon copolymer

A method is provided for producing a thermoplastic resin sheet or film by hot-melting and then cooling a thermoplastic resin to form a sheet or film. The thermoplastic resin sheet or film is moved so that it is pressed against the outer surface of an external heated roll and against a heated, endless metal belt. The endless metal belt is disposed at one end around a moving, internal heating roll and at an opposite end thereof around a moving, internal cooling roll. The internal heating roll heats the endless metal belt to a temperature higher than the softening point of the thermoplastic resin and higher than the temperature of the external heating roll to thermally adhere the thermoplastic resin sheet or film to the external heated roll or the heated, endless metal belt. The thermoplastic resin sheet or film is then moved along on the external heated roll or belt into a high temperature zone. The thermoplastic resin sheet or film is then released from the contact with the external heated roll and released from contact with the endless metal belt in a low temperature zone. The thermoplastic resin sheet or film is then peeled from the endless metal belt. Methods are also provided for producing a laminate of two or more thermoplastic resin sheets or films. The above methods provide non-stretched thermoplastic resin sheets, films or laminates with high-quality surfaces, which are suitable for wrapping foods and medicines.

Method for producing thermoplastic resin sheet or film.

A water flow guide stationarily mounted in the water box of an underwater pelletizer to selectively direct the pressurized water flowing through the water box in order to more efficiently cool and rigidify the extruded polymer strands and enable the rotary cutter blades to more effectively shear the strands into pellets and to convey the sheared pellets away from the die face and rotary cutter blades of the pelletizer to the water box outlet. The water flow guide provides an accurately guided pressurized water flow which enables pelletization of polymers of various diameters and a wide range of specific gravity and rheological characteristics.

Flow guide for underwater pelletizer

The invention provides a method for the preparation of a sheet of a crystalline thermoplastic resin, e.g. polypropylene, having excellent transparency and surface properties as well as thermoformability. The inventive method comprises quenching of a molten resin sheet extruded out of a T-die by introducing the same into a slit where cooling water is flowing at a velocity higher than the running velocity of the extruded molten resin sheet and then stretching the thus quenched resin sheet in a stretch ratio in the range from 1.02 to 1.5 times.

Method for the preparation of a crystalline thermoplastic resin sheet

PROBLEM TO BE SOLVED: To provide a thermoplastic resin film suitable for optical use, by restraining nonuniformity of the thickness, when manufacturing the thermoplastic resin film by a melting film forming method. SOLUTION: This apparatus has a die 16 which discharges a molten thermoplastic resin in a film shape, a cooling roll 18 which is arranged so as to oppose to a discharge port of the die 16 and cools and solidifies the discharged film 12A, and a shielding means which shields at least an end part in the width direction of the film 12A up to landing on a surface of the cooling roll 18 from the discharge port of the die 16 between an end part in the width direction of the cooling roll 18 and the end part in the width direction of the film 12A. COPYRIGHT: (C)2009,JPO&INPIT

Apparatus for manufacturing thermoplastic resin film and method for manufacturing thermoplastic resin film

Plastic polyolefin sheets may be formed by passing extruded resin through a primary cooling zone having a moving, smooth free surface on the cooling liquid, cooling being effected by laminar flow cooling liquid and thence by turbulent flow cooling liquid.

Edward B Kaplan

Papers

Production of thermoplastic sheet