Plastic wood fiber foam structure and method of producing same
US6936200B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 7, 2001 |
| Grant date | Aug 30, 2005 |
| Priority date | — |
| Expiry date | Mar 3, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2201/03
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process for producing plastic/wood fiber composite foamed structures includes the steps of pre-drying wood fiber filler; mixing it with plastic to form a mixture; feeding the mixture into an extruder; introducing and mixing a blowing agent; subject the mixture to high shear forces and extruding the mixture to produce a plastic/wood fiber composite foamed structure. The filler has a degradation temperature and an active volatization temperature. During the pre-drying step the temperature is maintained below the degradation temperature. During the mixing step the mixing temperature is maintained below the active volatilizing temperature. During the introducing and mixing step a blowing agent is introduced into the plastic/wood fiber mixture and is mixed therewith to produce a plastic/wood fiber/gas mixture. During the subjecting step the plastic/wood fiber/gas mixture is subjected to high shear forces in the presence of high pressures and the temperature is maintained below an active volatilizing temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.