Double injection mold with neck gating
AssigneeRainville Company, Inc.
InventorDewey Rainville
Life of this patent
Estimating the term…
Abstract
A parison for blow molding is applied to a core rod by successive injection operations in different injection molds. The material for the first layer is injected into the end of the mold cavity remote from the neck portion of the core rod, in the usual manner. The second layer is injected into the second injection mold cavity adjacent to the neck of the core rod to flow over the first layer in a direction from the cooler part of the first layer toward the hotter part. The twolayer parison is then transferred to a blowing mold where it is blown in the usual way.
Claims6
Molding apparatus including a first and a second injection mold, a core rod movable from one mold to the other, each injection mold having a cavity with means at one end for gripping the neck end of the core rod when the core rod is in the mold, each injection mold having a passage through which plastic is injected into the cavity, one of the molds having its injection passage at an end of the cavity at which the core rod is gripped and the other mold having its injection passage at the other end of its cavity, means for injecting material about said core rod in said first mold cavity and sequentially moving the core rod from said first mold cavity to the next, and for injecting a superimposed layer of molding material about said core rod is said second mold cavity to form a two-layer parison on the core rod.
Dependencies are inferred from the claim text.