| abstract |
A method of treating PET preforms and bottles consists of subjecting the preforms or the bottles to a carbon dioxide atmosphere at a higher temperature than the critical temperature of carbon dioxide, a higher pressure than ambient pressure, and for a set time period. The treatment greatly reduces both the acetaldehyde concentration in the head of the treated bottles or in the bottles obtained from said treated preforms by stretch-blowing, and permeability of gases through the bottle walls. |