Method for thermally conditioning a thermoplastic preform
US4571173A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 1984 |
| Grant date | Feb 18, 1986 |
| Priority date | — |
| Expiry date | Sep 20, 2004 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2067/00
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method is disclosed for thermally conditioning an essentially tubular parison of polyethylene terephthalate material to a desired orientation temperature at which the polyethylene terephthalate material can be biaxially stretched. The method comprises the steps of heating the parison by applying heat to the exterior surface thereof until the surface reaches a maximum heating temperature less than the temperature at which the polyethylene terephthalate material begins to crystalize and then cooling the heated exterior surface of the parison to remove the heat therefrom while the heat within the wall of the parison diffuses therethrough to raise the temperature of the opposing interior surface toward the desired orientation temperature. The method further includes the subsequent steps of reheating the parison by applying heat to the cooled exterior surface thereof until the surface reaches a temperature no higher than the maximum heating temperature to again add heat within the wall of the parison and then recooling the reheated exterior surface of the parison to again remove the heat therefrom until the additional heat within the wall of the parison diffuses therethrough to furthe…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.