Method of making a laminated container wall structure
Abstract
Abstract A method of manufacturing a laminated metal container wall having an integral opening device. Providing a metal sheet, coating the sheet with an adhesive selected from the group consisting of epoxy, polyester and polyurethane and subsequently securing to the sheet by means of the adhesive a continuous layer of barrier material selected from the group consisting of lowdensity polyethylene, high-density polyethylene and cast polypropylene. Subsequently scoring said sheet to define a severable and/or removable sector and leaving residual metal along the score line of a thickness of about 0.002 to 0.006 inch. Effecting the scoring while preserving the integrity of the barrier by maintaining continuity of the layer of barrier material. Simultaneously with the scoring operation reducing the thickness of the barrier material in the regions underlying the scoring through compressibly established flow without penetrating entirely through the layer. This compressibly established flow serves to reduce the shear resistance to severance of the barrier when the laminated container wall is opened. An outer protective material selected from the group consisting of a polyester, polyvinylidene chloride, polyvinyl chloride and medium- or highdensity polyethylene may be continuously secured to the barrier material. A laminated metal container wall made by the above method having a barrier material thickness of about 0.002 to 0.003 inch in the portion not underlying the score line and a reduced thickness in the portion underlying the score line. The barrier material having a continuous panel covering structure. An outer protective material selected from the medium- consisting of a polyester, polyvinylidene chloride, polyvinyl chloride and medium- or highdensity polyethylene secured to the barrier material.
Inventors
- 👤 Herbert Gayner
- 👤 John N Demsey Jr
Bibliographic Details
Claims Analysis
Total Claims: 6References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |