Apparatus for sealing film including sealing head with wedge-shaped lower-portion
US4976811A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 12, 1988 |
| Grant date | Dec 11, 1990 |
| Priority date | — |
| Expiry date | Jul 12, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T156/1739
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Apparatus for manufacturing plastic film stock material including a sealing head utilizing heated air for continuous welding of reclosable plastic closure strips of plastic film. The sealing head is an elongated block having tapered walls which form a narrow bottom edge. The edge is curved longitudinally to match the curvature of a cooperating platen to define a small welding gap through which pass plastic webs to be welded. The sealing head includes a plurality of air distribution manifolds interconnected by passageways to provide a tortuous path for air flowing through the head from an inlet to an elongated, narrow exit slot formed at the bottom edge of the head. Multiple sealing heads are mounted on a carrier frame for positioning adjacent the platen to produce elongated welds to secure two-piece closure strips to a plastic web.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.