METHOD OF OBTAINING THICK-WALLED CASTINGS FROM POLYMERIC MATERIAL Russian patent published in 2015 - IPC B29C45/12 B29C45/72 B29C45/33 B22D17/22 

FIELD: metallurgy.

SUBSTANCE: in a casting mould (fig. 5) the polymeric material smelt is converted into the casting 8 which is taken out from there and hardened. During hardening of the casting 8 it is forcibly hardened at varying rate. The casting mould with variable volume of the cavity is used which contains the mobile piston with a possibility of retraction during moulding, providing mixing of smelt of polymeric material. The variable volume of the casting mould cavity is provided because the casting mould contains the mobile piston. The casting is taken out from the casting mould by its pushing out by the mobile piston. The forced hardening of the casting at variable rate is performed on the basis of thermal insulation of its certain surfaces, for example, end faces using the heat-insulating material 17. The forced hardening of the casting at variable rate is performed on the basis of heating of its certain surfaces. The forced hardening of the casting at variable rate is performed on the basis of forced cooling of its certain surfaces.

EFFECT: prevention of formation of shrinkage cavities inside thick-walled castings by control of the process of hardening of their material.

2 cl, 8 dwg