METHOD AND DEVICE FOR HEATING PREFORM

摘要

A method of heating a preform, comprising the steps of applying a first heating processing of rapid heating to the preform formed on a bottle body by biaxial stretching blow by operating a heat source at a high output while blowing cooling air to the preform, applying a temperature controlling processing to reduce a temperature difference between the outer surface temperature and inner surface temperature of the preform to a specified value or below by leaving the heated preform as it is, and applying a second heating processing to the temperature controlled preform to heat the preform until the outer surface temperature is increased to a temperature slightly lower than the crystallization temperature of a PET while blowing cooling air to the preform, whereby the rapid heating of the preform can be safely achieved without causing overheating.