Rotational molding method and apparatus

摘要

The present invention refers to a process and apparatus for manufacturing plastic articles through the rotational molding method, and is more particularly addressed to a process and apparatus of rotomolding in furnace for manufacturing containers with multiple layers. The apparatus of the present invention uses a series of bins for the introduction of the materials to be molten on the molds, which are controlled by a computerized control panel.

主权项

1. A rotomoulding apparatus comprising:
a furnace delimited by walls and having a molding chamber therein; and a system for feeding a thermoplastic material into the furnace, wherein the furnace comprises:
(i) means for holding molds;(ii) a plurality of molds attached to said means for holding molds within which the thermoplastic material is provided;(iii) heating means; and(iv) means that transmits rotational movement to the molds, and wherein:
a) the apparatus further comprises a cooling system formed by a liquid cooling equipment that is coupled to a liquid distribution means,b) the furnace has one or more gates formed on one of its walls, each of the gates designed for allowing introduction of at least one bin towards the furnace, the at least one bin being a structure for carrying the thermoplastic material from a position located out of the furnace and adjacent the gates to a position inside one of the molds positioned inside the furnace, each bin being attached to an arm that has (i) means for moving the bin forward and backward in order to introduce it and remove it through one of the gates; and (ii) means for rotating the arm in order to turn around the bin and pour its contents into the molds within the furnace, andc) each bin comprises a double bottom structure, in such a manner that among its two walls, a chamber is formed, through which a liquid that comes from the cooling equipment is circulated; each bin has two openings, an inlet and an outlet, the liquid enters through the inlet opening, circulates through the chamber of the bin, and exits through the outlet opening.