Head for extrusion of a tubular parison formed of at least one layer of material
US4472129A · kind A · utility
56Cited by
16References
17Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Apr 5, 1982 |
| Grant date | Sep 18, 1984 |
| Priority date | — |
| Expiry date | Apr 5, 2002 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2948/92904
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Improved extrusion head for use in forming plastic containers or tubular films (optionally with multi-ply walls) by the extrusion-blowing process. The typical extrusion head used in this process has flat compensating rings bounding a portion of the frustoconical flow passages which ultimately feed the extrusion orifice. These are replaced by spherical segmental rings having a beveled surface in the form of a spherical, conical, toric or ogival shape which bounds said flow passage and thus eliminates stagnating recesses (of the type encountered through use of the prior art flat rings).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.