Method and apparatus for making foamed plastic slab
US4252757A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 1979 |
| Grant date | Feb 24, 1981 |
| Priority date | — |
| Expiry date | May 11, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S264/84
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
In the manufacture of foamed plastic slab by introducing foamable fluid from a mixing head into a moving conveyor-type mold, the improvement wherein supplemental quantities of the fluid are conducted from the mixing head longitudinally to locations where the main body of the material has foamed to partly expanded condition and friction between the sides of the mold and expanding material has caused the upper longitudinal side edges of the expanding material to assume a rounded shape which curves away from the mold sides leaving a space. The supplemental material is introduced into the spaces while the mold moves and upon expansion substantially fills the spaces and thereby greatly reduces the amount of the slab which must be cropped off prior to cutting it to form saleable articles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.