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

An injection molding method in which plastic material from a source is injected into at least one mold cavity, comprising the steps of:

• (a) combining first and second mold parts to define therebetween an insulated section of a runner system through which molten plastic material from the source is injected into the at least one mold cavity;
• (b) separating the first and second mold parts from one another;
• and
• (c) restraining a shell of plastic material within at least a part of said insulated section of the runner system from contacting any portion of at least one of the mold parts within said insulated section of the runner system other than means for effecting said restraint when the first and second mold parts are separated from one another.