| 摘要 |
PCT No. PCT/NZ95/00102 Sec. 371 Date Jun. 9, 1997 Sec. 102(e) Date Jun. 9, 1997 PCT Filed Oct. 10, 1995 PCT Pub. No. WO96/11096 PCT Pub. Date Apr. 18, 1996A technique of producing polyolefin foam is described. A two-stage process is described wherein the first stage involves expanding a preformed cylindrical tube comprising a polymer, blowing agent, cross-linking agent and blowing agent activator in an enclosed cylindrical mold. The cylindrical mold constrains the expansion of the foam without the need for hydraulic rams or similar mechanical means as are found in conventional platen presses. Following stage one, the cylindrical tubes of material are heated while unconstrained and expands symmetrically. The cylindrical tube of expanded foam material is then slit and may be cold pressed in order to form polyolefin foam blands. Variations on the cylindrical tube mold shape may be used and patterns and other features may be formed on the interior of the cylindrical mold in order to produce a product containing the imprint thereof. Polyolefin foam so produced may be used in building, packaging, clothing and similar applications. |
