Roll fed flotation/impingement air ovens and related thermoforming systems for corrugation-free heating and expanding of gas impregnated thermoplastic webs
US8568125B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 2009 |
| Grant date | Oct 29, 2013 |
| Priority date | — |
| Expiry date | Jan 4, 2030 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2105/041
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Disclosed herein are roll fed air heated flotation ovens and related thermoforming systems, assemblies, and machines that enable the corrugation-free expansion of a gas impregnated thermoplastic web passing through an oven chamber (without use of a pin-chain assembly), as well as to related methods. In an embodiment, a gas impregnated thermoplastic web is conveyed and expanded through an elongated air heated oven chamber, wherein the elongated oven chamber includes a plurality of downwardly directed heated air nozzles positioned at regular intervals along and within the upper portion of the oven chamber, and a plurality of upwardly directed heated air nozzles positioned at regular intervals along and within the lower portion of the oven chamber, but staggered apart from the downwardly directed heated air nozzles such that the gas impregnated thermoplastic material web undulates in an up and down wavelike fashion, thereby minimizing sagging, bagging, puckering, and/or buckling of the web.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.