Refrigerant cooled plastics moulding.

摘要

The mould (A) of a plastics moulding machine having a plurality of cooling fluid passageways (3) is cooled by supplying liquid phase hydrocarbon refrigerant through distributors (13) to lines (14) extending to the individual passageways (3). The lines (14) have respective metering devices, such as needle valves (16) therein, which are so adjusted that a boiling liquid phase and vapour phase refrigerant mixture is obtained throughout each of the cooling fluid passageways (3). Sight glasses (18) downstream of the passageways (3) allow the state of the refrigerant to be checked visually. The invention allows mould cooling rates to be increased without resorting to extremely low coolant temperatures or extremely high coolant flow rates.