| 摘要 |
PURPOSE:To manufacture a bottom material of good accuracy by means of low temperature heat press molding by providing the given characteristics of tensile strength, elongation, softening temperature and degree of vertical heat shrinkability respectively. CONSTITUTION:First a vinyl chloride sheet 8 is fed from a feeding roller 2 and heated to approximately 60 - 80 deg.C by a far infrared ray heater 3. Then the sheet 8 is fed to a sandwich direction direct heater 4 where it is heated up to approximately 100 deg.C. Then the sheet 8 is fed into a press device 5, and pressing work is carried out in the state of being vacuumized while being cooled slightly. A bottom material 11 pressed molded by the press device 5 is then wound on a wind-up roller 6. Said sheet 8 is provided with elongation characteristics of 200 % or more at the heating temperature of approximately 100 deg.C and also with the given tensile strength or more (400 kg/m<2> or more), and the bottom material of given strength without cutting of sheet can be manufactured. Further, the softening temperature of the sheet 8 is set at 56+ or -2 deg.C and degree of vertical heat shrinkability within 4.5 %, and the bottom material of good accuracy with little shrinkage of the sheet can be manufactured. |
