Method and apparatus for restraining plastic material in insulated runner system from contacting mold parts upon separation thereof

摘要

In an injection molding apparatus in which first and second mold parts are combined to define therebetween an insulated section of a runner system through which molten plastic material is injected into at least one mold cavity, spring-biased plungers are included in at least one of the first and second mold parts for restraining a shell of plastic material within at least a part of the insulated section of the runner system from contacting any portion of at least one of the mold parts within the insulated section of the runner system other than the plungers when the first and second mold parts are separated from one another.