摘要 |
<p>The method for manufacturing an article having a surface, a skin, and a core includes closing a first mold portion on a compressible seal. The seal is disposed between the first and second mold portions. The portions define a pressurizable mold cavity having a spaced apart injection port and a vent. The mold cavity is pressurized at a first pressure greater than atmospheric pressure. Molten plastic and a blowing agent are injected form gas cells within the mixture. The gas cells have an internal pressure exceeding the first pressure. After waiting for a first period, the pressurizing gas is vented for a second period at a rate sufficient to rupture the gas cells which form a skin adjacent to the mold cavity wall. The skin defines a core cavity filled with the foamed mixture, which is solidified. The mold portions are separated releasing the article.</p> |