Method and apparatus for manufacturing of a container
US5429777A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 12, 1993 |
| Grant date | Jul 4, 1995 |
| Priority date | — |
| Expiry date | Apr 12, 2013 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29L2031/7132
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method and an apparatus to thermocrystallize amorphous thermoplastic material in a bottom portion (11) of a preform (10) while producing a container. By means of at least one heating device (20, 30) the plastic material is heated to an elevated temperature at which the material crystallizes thermally. The supply of energy is discontinued once the material crystallizes at a speed entailing that the thus released effect corresponds to or exceeds that effect which departs from the material undergoing crystallization. The apparatus includes a mandrel (26) having a forming surface (24) which at an increased temperature is brought into abutment against a defining surface (18) of the bottom potion. The forming surface has a curvature which deviates from the curvature of the defining surface (18) so that during the initial phase of the abutment the forming surface is abutting against the defining surface only in a central area thereof. On continued displacement of material in the bottom portion in order to form the portion the size of the central area thermoplastic material intended for temperature-conditioning abuts against the forming surfaces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.