Process of producing thermoplastic resin sheet and equipment therefor
AssigneeIdemitsu Petrochemical Co., Ltd.
InventorsToyokazu Takubo, Atsushi Fujii
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Abstract
This invention relates to a process of producing a thermoplastic resin sheet and equipment therefore. The equipment includes a first extruder of a high kneading type, a second extruder of a low kneading type and an extrusion die. A film-shaped resin extruded from the extrusion die is cooled by a cooling device, to thereby obtain the resin sheet. Additionally, a difference between pressures at the outlets of the first and second extruders is detected, and, in response to this difference between the pressures thus detected, the operating conditions of the first extruder are automatically controlled.
Claims12
A process for producing a thermoplastic resin sheet comprising the steps of kneading the thermoplastic resin in a first extruder of a high kneading type and extruding the thermoplastic resin in a molten state;
- introducing the molten resin into a gear pump in which the molten resin is additionally kneaded;
- supplying the molten resin from the gear pump to a second extruder of a low kneading type;
- extruding a molten film-shaped resin from said second extruder through a die located at the outlet of said second extruder;
- and introducing said molten film-shaped resin through a slit, at an inlet of which cooling water flows in such a manner that it does not stagnate and uniformly cools said molten film-shaped resin.
An apparatus for producing a thermoplastic resin sheet comprising:
- a first extruder;
- a second extruder serially connected to said first extruder through a pipe means located therebetween;
- a gear pump located on an intermediate portion of said pipe means;
- a die provided on the extrusion side of said second extruder through which a molten film-shaped resin is extruded;
- and
- a cooling device for cooling said molten film-shaped resin, said cooling device being provided with a slit through which said molten film-shaped resin passes and cooling water flows so as to uniformly cool said molten film-shaped resin.
A process for producing a thermoplastic resin sheet comprising the steps of kneading the thermoplastic resin in a first extruder having a compression ratio of 2 or more and extruding the thermoplastic resin in a molten state;
- introducing the molten resin into a gear pump in which the molten resin is additionally kneaded;
- supplying the molten resin from the gear pump to a second extruder having a compression ratio of less than 2, maintaining the difference in pressures at the discharge of the gear pump and the outlet of the second extruder at a constant amount;
- extruding a molten film-shaped resin from said second extruder through a die located at the outlet of the second extruder;
- and introducing said molten film-shaped resin through a slit, at an inlet of which cooling water flows in such a manner that it does not stagnate and uniformly cools said molten film shaped resin.
Dependencies are inferred from the claim text.