Method of forming container with high-crystallinity sidewall and low-crystallinity base
US5829614A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 1996 |
| Grant date | Nov 3, 1998 |
| Priority date | — |
| Expiry date | May 24, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1397
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method of making a polyester container having an enhanced level of crystallinity in the sidewall while maintaining a low level of crystallinity in a thickened base portion. The container is particularly useful as a refillable container which can withstand higher caustic wash temperatures and exhibits reduced flavor carryover, or as a hot-fill container. According to the method, a sidewall-forming section of a preform is initially expanded, heated to contract and crystallize the same, and than reexpanded; a base-forming portion of the preform is shielded from the heat treatment and is expanded either before or after the heat treatment step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.