| 摘要 |
PROBLEM TO BE SOLVED: To realize the high sped production of a thermoplastic resin sheet containing a plasticizer, by which excellent thickness accuracy, heat shrinkage factor and external appearance are obtained, by a method wherein an oriented sheet is cooled under the condition being pressurized through pinching so as to introduce the obtained sheet in a cooling water tank and finally orient it again. SOLUTION: After being extruded from a mold 1 into a form of a sheet by feeding a composition containing a thermoplastic resin and a plasticizer to an extruder, a shaped matter is oriented with a cold pressing device and pressurized through pinching so as to introduce the resultant cooled sheet in a cooling water tank 4 in order to orient again after being cooled down completely. The draw ratio of the sheet applied during the process ranging from the outlet of the mold 1 to the cooling rolls 2 and 3 provided in the cold pressing device is preferably set to be as large as possible. Because the sheet extruded from the outlet of the mold 1 is in the viscous region under a high temperature molten state, resulting in causing no recovering of the strain developing during orienting under the temperature, which is lower than the temperature of the sheet extruded from the outlet of the mold. |
