The principle of mold temperature balance in plastic mold cooling system design

The principle of mold temperature balance:

1. Due to the complexity of the plastic parts and mold structure, it is difficult to make the temperature of the mold completely consistent, but should be make the mold temperature as balanced as possible, and there should be no local overheating or overcooling.

2. The high temperature areas in the mold including: near the sprue bushing, near the gate, and near the thick wall of the plastic part, these areas should be cooled.

3. Heating is sometimes required at thin-walled areas.

4. During the cooling process of the mold, due to the phenomenon of thermal expansion and contraction, the plastic part will slightly detach from the fixed mold cavity when the solid shrinks, while the tightening force on the core is getting bigger and biggger, and the plastic part is detaching, the more heat before demolding is transferred to the core, so the core must be focused on cooling.

5. To control the temperature difference of the cooling water at the inlet and outlet of the cooling channel, the temperature difference should be less than or equal to 2°C during precision injection molding, and in general, the temperature difference should be less than or equal to 5°C. the total length of the cooling gate (series length) should not be too long, preferably less than 1.5m, and the length of the dead zone should be as short as possible.

6. The cooling channel must be designed for the stripper in the three-plate mold, t, so that the mold temperature can be stabilized during the production process and the molding cycle can be shortened.

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