VACUUM MOLDING OF THERMOSET SHEET ARTICLES

摘要

A process of compression molding an article from a curable resin is provided that includes opening a mold to an open position by displacing an upper die having an upper mold surface from a lower die having a lower mold surface. Resin is placed a mold surface and the dies are closed to an intermediate start position at a rate of from 1 to 10 cm/sec. The dies are then closed to a start position at a rate of between 25 and 60% of the rate of closure to the intermediate position. A shroud volume is evacuated for at least 3 seconds to a reduced pressure of less than 0.16 atmospheres while continuing to press toward a mold cavity volume at a rate of between 12 and 30% of the rate of closure to the intermediate start. The reduced pressure is removed as the full compression is applied.