摘要 |
The invention relates to a process for the production of expanded or expandable polyolefin beads by impregnating polyolefin granules with a volatile blowing agent in suspension under pressure. As suspension aid, use is made of a mixture of a water-insoluble inorganic compound and a surfactant, and the impregnation is carried out in the presence of a surface-active polymer carrying carboxyl or carboxylate groups.
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