초록 ▼

Apparatus and method are described for injection molding of thermoplastic paint cans substantially similar in size and design to the conventional steel one-gallon paint can. The apparatus comprises a cavity element defining the exterior of the container body and a core mold element including a perip

Apparatus and method are described for injection molding of thermoplastic paint cans substantially similar in size and design to the conventional steel one-gallon paint can. The apparatus comprises a cavity element defining the exterior of the container body and a core mold element including a peripheral lip protruding into the interior of the can body at a point below the upper terminus of the top circumference of the container body, thus providing a peripheral upwardly projecting edge. The cavity element includes a plurality of cam elements which move cooperatively on separation of the core and cavity elements. The cam elements grip the ridge of the container and expand it outwardly sufficiently to permit the core element of the mold to be removed from the container without hindrance from the inwardly protruding lip.

대표청구항 ▼

Method of removing a mold core from the interior of a newly molded thermoplastic container having an upper edge and an integral molded part peripherally obstructing the path of separation from the mold core by peripherally projecting into the mold core near the upper edge of the container, comprisin

Method of removing a mold core from the interior of a newly molded thermoplastic container having an upper edge and an integral molded part peripherally obstructing the path of separation from the mold core by peripherally projecting into the mold core near the upper edge of the container, comprising radially bending and stretching the body of the container to radially expand the peripherally obstructing part away from the mold core to a diameter greater than that of the mold core by the application of radial outward pressure on the upper edge of the container, and thereafter removing the mold core. Apparatus of claim 7 wherein the cams have surfaces as part of the mold cavity in addition to surfaces on the mold core.