Apparatus for producing a tubular object of polyethelene terephthalate or other thermoplastic material from a tubular blank of amorphous material
US4929168A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 1986 |
| Grant date | May 29, 1990 |
| Priority date | — |
| Expiry date | Oct 21, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1397
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An object is produced from a tubular blank (10,15,17) of thermoplastic material of the type polyester or polyamide, preferably of polyethylene terephthalate by reducing the thickness of amorphous material in one or several areas of the blank by means of one single or several consecutive re-shaping operations. A mechanical shaping device (23,29,71,81) moves a transitional zone (13,14,113) situated between thicker and thinner materials along the blank and elongates simultaneously the blank in the moving direction of the transitional zone. After the last re-shaping operation the thinner material has preferably an oriented state. During the re-shaping operation the temperature of the material in the transitional zone (13,14,113) is controlled at a level which, immediately before the re-shaping operation, is within or close to the range of the glass transition temperature (TG). In one embodiment the reduction of the wall thickness of the material is begun in a track (12) in the wall of the blank and continues symmetrically around the track. Clamping devices (41,51,61) are used to maintain the axial position of the blank. The blank is suitable for re-shaping for instance into a container…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.