When the mold temperature for a part has been established, an appropriate coolant can be selected. Coolant temperatures are typically 10ºC cooler than the mold surface.
|Ordinary water from mains or a cooling tower||20 to 25°C|
|Cold water from a chiller||above 10°C|
|Water mixed with antifreeze (usually glycol) from a chiller||-5°C|
|Oil—normally from a heater/circulator unit||80°C or above|
Adding glycol to the coolant will raise its viscosity, resulting in a higher pumping pressure being required, or a lower flow rate. Using a chilled water and glycol mix may be less effective than a well designed cooling circuit with plain tower water circulating at the optimum flow rate. Oil is used only when very high mold temperatures are required.