The temperature of the coolant as it enters the cooling system is an important aspect to consider for a Cool analysis.
To achieve effective heat extraction from the part, the coolant temperature should not increase by more than 2–3°C from inlet to outlet. A greater increase may indicate a problem with the cooling system design.
The Cool analysis log records the change in coolant temperature from inlet to outlet. If the increase is unacceptable, that is greater than 2–3°C, you can use the coolant temperature result to determine where the greatest increase in temperature occurs. If necessary, the inlet temperature and the degree of turbulence in the cooling channels can be altered to increase heat extraction in areas that are difficult to cool.
The temperature of the coolant should be as low as possible, in order to achieve the best heat transfer and the lowest cycle time. However, some thermoplastics need a higher surface temperature for better part finish. Heated water or oil may be used for cooling the mold in these cases. Try to keep the mold surface temperature close to the recommended value.
In general, use an inlet temperature of 10–20°C lower than the desired mold temperature. However, you should know what temperature coolant the coolant circulating plant is able to provide. There is no benefit specifying a coolant inlet temperature of 5°C, if no chiller is available to achieve this value. Also, the tower water temperature will vary depending on geographical location and ambient conditions. The inlets and outlets should ideally always be positioned on the bottom of the mold, to eliminate the risk of coolant dripping onto the mold faces.