STERILIZATION METHOD FOR PREFORM

摘要

PROBLEM TO BE SOLVED: To improve sterilization effect of a preform by use of hydrogen peroxide.SOLUTION: A corona discharge processing including: a voltage application step of applying a voltage which is generated by corona discharge to an electrode which can pass an opening of a preform comprising polyethylene terephthalate as a main material; an insertion step of inserting the voltage applied electrode into the preform through the opening; and a bottom processing step of an inner surface of a bottom of the preform in such a manner that the electrode approaches the bottom of the preform until a mode of corona discharge from the electrode is changed. After said corona discharge processing is carried out for the inner surface of the preform, sterilization treatment including a hydrogen peroxide supply step of spraying mist or gas of a hydrogen peroxide solution or a mixture thereof onto the preform is carried out for the preform.SELECTED DRAWING: Figure 1