| 摘要 |
PURPOSE:To make it possible to obtain containers excellent in transparency and uniformity with favorable productivity by a method wherein a crystalline thermoplastic resin sheet is heated under the state being pinched between heating parts provided with heating surfaces having a predetermined surface roughness and, after that, introduced in a thermoforming part in order to be thermoformed. CONSTITUTION:A sheet 1, which is carried and introduced in a preheating part 11, is pinched between heating plates 11a and 11b so as to bring their heating surfaces 13a and 13b into contact with the sheet 1 in order to heat both sides of the sheet. At this time, the temperature of the heating plate is held at a temperature of the melting point of the sheet or less and the surface roughness of the heating surfaces 13a and 13b is made to be 3S or lower. At a thermoforming part 14, the sheet is heated by a heating plate 15, pressure air is sent through the vent holes 15b of a heating surface 16 and at the same time the deaeration of the cavity part 19 on a mold surface is performed through vent holes 19a. Thus, the sheet 1 is press-fittingly formed in the cavity part 19 and the effect to obtain good quality containers excellent in mold reproducibility, transparency, uniformity, brilliance and the like with favorable productivity is realized. |
