Method of forming foam articles from a foam thermoplastic web
US4302415A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 16, 1979 |
| Grant date | Nov 24, 1981 |
| Priority date | — |
| Expiry date | Apr 16, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2105/04
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A web of thermoplastic foam material is carried through an oven by an intermittently traveling conveyor engaging or gripping opposite sides of the web. The heated web is successively advanced by the conveyor between cooled heat-absorbing forming molds, which are moved toward each other to form the foam article and away from each other to release the article. A heat trimmer melts or vaporizes the leading and trailing ends of the foam material as compressed and formed by the molds, to form the marginal leading and trailing ends of the articles to the required peripheral form determined by the leading and trailing ends or edges of the molds and to separate the leading and trailing ends of the article from the web. The cooled molds, which may be made of a heat-conducting metal, such as aluminum, absorb the heat of melting as they pressurize the material along its edges and thereby determine the leading and trailing margins of the article. The web, as advanced from the molds, is then trimmed along the side margins of the article which are preferably straight, by straight dies which sever the article from the web. The severed articles are then stacked with the leading article on top and …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.