| 摘要 |
PURPOSE:To prevent the bottom of a drawing blow molded bottle from whitening and improve the thermal resistance thereof, by a method wherein the bottom of the drawing blow molded bottle is reheated in a mold to a temperature between the softening point and the melting point of resin and remolded by drawing. CONSTITUTION:A molded bottle B previously drawing-blow-molded in a mold X is treated by the heating from the mold X and/or the radiant heating from a radiant heat source 8. The bottom 1 of the bottle B, which is a part of small elongation, is softened through heating by means of a bottom part telescopic mold 5 heated separately from the mold main body 7 to draw as well as to treat with heat. The drawing is performed by a method wherein the inside of the bottle B is pressurized to approximately 1.2-6atm., and also such a method is employed wherein the bottom part mold is used as a plug assist to perform molding against the internal pressure. In order to soften said bottom part, the temperature is raised to somewhere between the softening point and the melting point of resin. |
