Apparatus for the continuous manufacture of phenolic resin foam in endless sheets
Abstract
Abstract An apparatus for the continuous manufacture of phenolic resin foam in an endless sheet which includes means for mixing expandable liquid phenolic resin with a blowing agent and an acid-containing curing agent, optionally with the addition of additives, and means for processing the mixture in a temperature-controllable double belt press. The apparatus also comprises a device for cooling the phenolic resin to a temperature of from about 8 to about 15° C., a mixing section for admixing a blowing agent under a high pressure with said resin to form a resin premix, for mixing said resin premix with a curing agent resin to form a resin premix, and mixing said resin premix with a curing agent and other foam additives to form a curable reaction mixture, an applicator device for continuously applying said mixture uniformily onto a moving substrate, a unit for covering the mixture on said substrate with a continuous protective layer, a conveyor belt for passing the covered mixture into the double belt press, means for heating the belt press to promote foaming of the mixture under pressure until a desired sheet thickness has been obtained and a device for measuring the foam pressure within said belt press so that the foaming pressure and also the sheet thickness can be regulated.
Inventors
- 👤 Klaus Bruning
- 👤 Hans Junger
- 👤 Wolfgang Pungs
- 👤 Peter Rheinfeld
- 👤 Franz Weissenfels
- 👤 Michael Wienand
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) | 1979-12-28 | 1980-06-28 | 1980-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-12-28 | 1984-06-28 | 1984-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-12-28 | 1988-06-28 | 1988-12-28 | $7700.00 | Window Closed / Lapsed |