Process for injection stretch blow molding
US5951938A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 1996 |
| Grant date | Sep 14, 1999 |
| Priority date | — |
| Expiry date | Sep 26, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2067/00
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An improved method for injection stretch blowing is provided. In the process, a molten resin is injected into an injection cavity defined by an injection mold, a lip mold and an injection core to form a desired preform, the cooling time for this preform being positively reduced to form a rigid skin layer on the outer surface of the preform without increasing the thickness. It is then released from the injection mold and transferred into the blow mold with a mouth portion being held with the lip mold while the skin layer keeps the configuration of the preform and the interior is in a high temperature state, and is stretch blow molded into a hollow molded article, e.g. a bottle whose major portion is ultra-thin, at the moment when the surface temperature of the preform that rises due to its own interior temperature is significantly higher than a glass transition temperature (Tg) and is expected to reach to a peak temperature. Thereby, it is possible to allow molding of a hollow molded article having a thickness of 0.17 mm or smaller without being affected by limitations of thickness of the preform and molding temperature even in a molding process where the preform is released from th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.