Apparatus for coextrusion of multilayer sheet or films
Abstract
Abstract This invention comprisea a multilayer laminated sheet for rigid packaging having an inner barrier laye r which is adhesively bonded to a polyolefin resin layer on one side and to a styrene polymer layer on the other side and a method and apparatus for making said laiminated sheet by coextrusion of all but the styrene polymer layer from a common die and immediately combing the resulting product with a styrene polumer sheet which is freshly extruded in tandem from a separate die. The invention further comprises a unique multilayer extrusion die configuration wherein a single thermoplastic substance is subdivided into layers of substantially equal thickness to the layers of other substances after which all of the layers are simultaneously united and extruded.
Inventors
- 👤 W Schrenk
- 👤 L Mounts
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |