Increasing the length of a cooling channel increases the surface area available for heat transfer.
In the following diagrams, the blue line represents the cooling channel in the mold. The cooling line in shown in diagram b will be more effective than those shown in diagram a. However, long channels can cause the following problems:
- Increased pressure drop
- Excessive temperature rise
- Difference between inlet and outlet temperature greater than 3°C
To avoid these problems, very long circuits should be broken into two or more shorter circuits as shown in diagram c.
