Method of jacketing tubular stock with polyolefin foam
Abstract
Abstract A METHOD OF JACKETING TUBULAR STOCK. METALLIC TUBULAR STOCK IS ADVANCED IN A PREDETERMINED DIRECTION THROUGH AN EXTRUDING DIE IN THE EXTRUDING HEAD OF AN EXTRUDER IN THIS EXTRUDING DIE A JACKET CONSISTING OF A MIXTURE OF PREPLASTICATED SYNTHETIC PLASTIC POLYOLEFIN MATERIAL AND AN AZODICARBONAMIDE BLOWING AGENT IS EXTRUDED ONTO THE OUTER CIRCUMFERENTIAL SURFACE OF THE ADVACING TUBULAR STOCK AND UNDERGOES FOAMING WHILE STILL WITHIN THE CONFINES OF THE DIE. AS THE JACKETED STOCK ISSUES FROM THE DIE IT PASSES THROUGH AN ANNULAR MEMBER HAVING AN INNER DIAMETER SLIGHTLY SMALLER THAN THE OUTER DIAMETER OF THE FOAMED JACKET SO THAT THE PERIPHERAL SURFACE LAYER OF THE JACKET IS DEFORMED INTO A CONTINUOUS SMOOTH SKIN. SUBSEQUENTLY, THE RESULTING JACKETED TUBULAR PRODUCT IS COOLED.
Inventors
- 👤 Helmut Benteler
- 👤 Wilhelm Lachenmayer
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-14 | 1975-09-13 | 1976-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-14 | 1979-09-13 | 1980-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-14 | 1983-09-13 | 1984-03-14 | $7700.00 | Window Closed / Lapsed |