| 摘要 |
PURPOSE:To improve stress cracking resistance of a bottle, by immersing only the bottom part of the bottle, which is orientation-blown, into a hot water or an organic solvent. CONSTITUTION:A preform made of saturated polyester is orientation-blown and bottle 1 is molded. Then only the bottom part 5 of the bottle 1 is immersed into a hot water or an organic solvent having a temperature of 20-50 deg.C and stress cracking resistance is improved. With this construction, generation of a crack in the bottom part 5 by an external factor such as the temperature or water or chemicals or a solvent is avoided. |
