Extrusion blow molding apparatus for preparing polyester articles
US8556621B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 9, 2011 |
| Grant date | Oct 15, 2013 |
| Priority date | — |
| Expiry date | Oct 23, 2031 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2067/003
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An extrusion blowmolding apparatus has an extrusion die having an upstream portion for receiving the thermoplastic polyester material and a downstream portion having a die head through which molten thermoplastic polyester material is flowed to form a parison suitable for extrusion blowmolding. The extrusion die has extending therethrough a generally cylindrical barrel and an extrusion screw disposed within the barrel having spiral flights along its length. In some aspects, the flight depths are lengthened so to provide a good melt at a suitable throughput. By also selecting an appropriate extrusion temperature profile, it is possible to eliminate or minimize unmelts, which can contribute to processing difficulties as well as defects in the resulting article. In other aspects, a closed-loop drying system is provided for achieving very low moisture levels in the polyester material to improve processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.