| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of effectively manufacturing a thermoplastic resin foamed sheet in which a cell of the sheet surface portion is finer than a cell of the intermediate portion. SOLUTION: In the manufacturing method of the thermoplastic resin foamed sheet of melting and kneading the thermoplastic resin and a physical foaming agent with an extruding machine, and extruding the foaming molten resin from a die, ultrasonic vibration is given to the foaming molten resin at the die lip portion, the amplitudeλof the ultrasonic vibration is not less than 5μm, and the amplitudeλand a die lip opening degree h (mm) satisfy the equation 1 wherein the equation 1 is 50≤1,000 h/λ≤600. COPYRIGHT: (C)2006,JPO&NCIPI |
