Method for forming foamed polypropylene resin sheet and foamed formed article
US6699421B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | May 8, 2002 |
| Grant date | Mar 2, 2004 |
| Priority date | — |
| Expiry date | Jun 13, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L2203/14
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Provided are a method for forming a foamed polypropylene resin sheet in which draw down and waving are not caused in heating the foamed sheet and in which inferior appearance such as partial thickness and wrinkles is not produced on the product, and a foamed formed article having an excellent shape obtained from the same. The method comprises a heating step for heating and softening the foamed polypropylene resin sheet and a forming step for bringing the heated foamed polypropylene resin sheet into contact with a forming mold to form it into a prescribed shape, wherein the foamed polypropylene resin sheet has an expansion ratio of 1.1 to 6 times, an open cell rate of 70% or less and a sheet thickness of 0.5 to 5 mm; and the foamed polypropylene resin sheet described above is heated in the heating step in the state that it is supported on a tabular sheet support.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.