Heat-shrinkable multilayer packaging film comprising inner layer comprising a polyester
US6610392B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 4, 1998 |
| Grant date | Aug 26, 2003 |
| Priority date | — |
| Expiry date | Mar 13, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31938
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A heat-shrinkable multilayer film comprises (A) a first layer, which is an outer layer, and which comprises polyolefin; (B) a second layer comprising at least one member selected from the group consisting of polyolefin, polystyrene, and polyurethane; (C) a third layer comprising at least one member selected from the group consisting of amorphous polyester and polyester having a melting point of from about 130° C. to about 260° C.; (D) a fourth layer, which is an outer layer, the fourth layer comprising at least one member selected from the group consisting of polyester, polyamide and polyurethane. The first layer preferably serves as a seal layer in a heat-shrinkable bag. The third layer provides enhanced impact strength, optics, grease-resistance, and free-shrink of the film, and renders the tape more easily orientable. The high melting polyester, polyamide, and/or polyurethane of the fourth layer permits at least two bags, having product therein, to be stacked on top of one another and sealed simultaneously, without sticking to one another, thereby doubling the output of a vacuum chamber machine. A bag and a process of making a packaged product are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.