| 摘要 |
2123483 9314137 PCTABS00024 A method and apparatus for forming articles made of polyurethane. The apparatus (10) includes a polyol weigh tank (12), an isocyanate weigh tank (20), an additive tank (26) and a mix tank (16) enclosed by a vent chamber (50). The vent chamber (50) is in communication with inlet (58) and outlet (60) pipes to move air and fumes from the interior of the vent chamber (50) past a filter (64). The apparatus (10) further includes a containment vessel (80) also having inlet (88) and outlet (90) pipes for movement of air and fumes. The containment vessel (80) is in communication with a pump (P) for creating a vacuum in the vessel (80) to reduce pressure in the interior of the vessel (80) in which a mold (110) is placed. The method includes the steps of: creating a vacuum around a mixture of at least one polyol, at least one isocyanate and at least one additive, to lower the pressure on the mixture below atmospheric pressure as the mixture expands; allowing the mixture to expand; reducing the vacuum to increase the pressure on the mixture in proportion to any further expansion of the mixture caused by the generation of a blowing influence in the mixture; and returning the pressure to atmospheric pressure. |
