Method of making side-gated preforms for use in blow molding plastic bottles

A method of injection molding a multi-layer plastic preform to be blow molded into a container comprising the steps of:

• providing a first mold cavity defined by sidewalls, an open end for accommodating a core rod, and a closed end with an injection gate therethrough;
• molding a plastic preform in said first mold cavity by injecting a plastic material through the gate;
• providing a second mold cavity having a longitudinal axis, sidewalls with a gate therein, an open end for accommodating a core rod and a closed end for forming a bottom area of the preform;
• inserting the molded preform into said second mold cavity;
• and
• injecting plastic materials for overmolding the preform into the second mold cavity transversely of the longitudinal axis through the gate of the second mold cavity at positions spaced from the closed end in order to avoid undesirable crystallization in the bottom area of the preform.