Method and apparatus for manufacturing plastic film with integral interlocking closure members incorporating shape conforming cooling shoes after extrusion
US5053091A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 1990 |
| Grant date | Oct 1, 1991 |
| Priority date | — |
| Expiry date | Jan 18, 2010 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29L2031/7282
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for use in extruding a plastic film with integral interlocking closure members. A flat plastic film and integral closure members are extruded through a single die opening. An air knife is used to push the extruded plastic film towards a chill roll and aids in the cooling of the film. The chill roll is rotatably driven and substantially cools the flat portion of the plastic film. Nozzles direct chilled air at the closure members. Cooling shoes are placed in close proximity to the extruded closure member and cool down and solidify the closure members. The cooling shoes are also used for shaping the closure members. The cooling shoes may be located adjacent the chill roll or adjacent a backing plate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.