Method for aligning extruded parison into sepentine-shaped mold cavity
US4865799A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 16, 1988 |
| Grant date | Sep 12, 1989 |
| Priority date | — |
| Expiry date | Jun 16, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29L2023/004
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
When blow molding elongated serpentine tubes or similar articles, loading of the mold cavity with the parison can present a problem. The parison can stick against the wall of the mold cavity. Moreover, a large diameter parison must be used, i.e. the parison must have a diameter equal to the total width dimension of the article, and consequently a large volume of flash is produced. The flash must be trimmed and recycled. In order to avoid these problems, inserts are placed in the mold to define portions of the mold cavity, particulary at corners. Air under pressure is fed into passages in the outer surfaces of the inserts and discharged through small orifices in such inserts against the parison to guide and drive the latter fully into the mold cavity. A vacuum can also be applied to the end of the cavity remote from the parison entry point for drawing the parison into the mold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.