Abstract: A method for degating an injection molded plastic article includes the steps of filling a mold cavity with a molten plastic, dwelling and cooling the mold subsequent to filling to effect gate seal. A first degating punch and a second punch are provided slidably inserted in holes in the mold which cross a gate in an axial direction, being the direction in which a movable mold half is opened and closed. The punches are vibrated at a high frequency after gate seal is completed in order to soften the solidified plastic in the gate. The punches are then displaced with respect to the gate when the plastic is softened in order to effect degating. In another method, a step of cutting the gate in the molded article by sliding the punches occurs during both dwelling after filling the mold with the molten plastic, and cooling subsequent to the completion of dwelling, and before gate seal is effected.

Abstract: A method of and apparatus for effectively drying pelletized or powdered plastic material by irradiation of the plastic material by microwaves while agitating it in a rotating drum that provides for sealing against leakage of plastic material or microwaves and provides means for exhausting moisture laden air therefrom. The combination of radiation by microwaves, even agitation by the rotating drum, and exhaustion of moisture driven from the plastic material provides a method of effectively drying plastic material uniformly, efficiently, and to a state of sufficient dryness for proper molding.

Abstract: A method for degating an injection molded article comprising the steps of filling a mold cavity with a molten resin and cooling the mold to effect gate seal. A gate cut shaft member is oscillated after gate seal is completed to soften the hardened resin in the gate. The gate cut shaft member is then displaced with respect to the mold cavity when the resin is softened to effect degating. A second method comprises the steps of cutting the gate in the molded article by sliding the gate cut shaft member during the dwell process with respect to the mold cavity after filling the mold with molten resin and before gate seal is effected. While said gate cut shaft member is subject to minute oscillation or a slow reciprocating motion, the shaft surface is abutted against the degated surface to obtain a good cut surface on the molded article.