MULTI-PART BLOW-MOLD FOR MAKING HOLLOW BODIES FROM THERMOPLASTIC MATERIAL

摘要

The parts of the blow-mold have cooling spaces for circulation of a coolant, and have a negative inner wall corresponding to the outer contours of the hollow body to be formed. Each blow-mold part includes a box-type metal body frame and a thin-walled insert presenting the negative contour, each insert being secured to the associated body frame and closing it off internally so that each insert and its associated body frame defines a respective cooling chamber of substantially the height of the insert. The inserts may be relatively thin sheet metal in which the contours are formed by cold working or cold shaping. The blow-mold has centering apertures, at each end, for a shoulder insert and a bottom insert both of which have recesses seating the sheet metal shell inserts. The cooling chamber is divided, for coolant circulation, by guide plates which are shorter than the height of the chamber and terminate alternately in engagement with the shoulder insert and with the bottom insert so that a zig-zag flow path is provided.