Injection molded plastic parts and method of forming
AssigneeElectrolux Zanussi Elettrodomestici S.p.A.
InventorPiero Durazzani
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Abstract
A large-sized and heavy part (1) of plastic material is injection molded. Localized zones are created in which the thermal conductance of the part (1) is higher in the surface impressions (10) at the mold ejectors for the removal of the part after it has been molded. In a preferred embodiment, the outer surface of the part (1) has, at the surface impressions (10), clusters of closed-bottom pits (13) formed by grids of mini-ribs (11) and (12) arranged perpendicularly with respect to each other. The thickness of the part varies from a maximum value (S1) at the periphery of the cavity to a minimum value (S2) at the bottom of a substantial number of the pits (13).
Claims12
An improved injection molded part (1) made of plastic material, comprising a plurality of surface impressions (10) at locations at which part ejectors provided in the mold exert pressure for ejecting the part after the part has been molded, characterized in that a thermal conductance of the part (1) is higher at said impressions (10) than in other zones of the part.
A part according to any of the preceding claims, characterized in that each impression (10) is substantially circular.
An improved method of injection molding a part made of plastic material comprising the steps of:
- injecting molten plastic into a mold to form the part;
- forming surface impressions in the part wherein the surface impressions have a higher thermal conductance than other zones of the part;
- and
- ejecting the part from the mold by exerting pressure at the surface impressions with a part ejector.
Dependencies are inferred from the claim text.