Mold cooling system overview

Importance of cooling system design

Mold cooling accounts for more than two-thirds of the total cycle time in the production of injection molded thermoplastic parts. Figure 1 illustrates this point. An efficient cooling circuit design reduces the cooling time, which, in turn, increases overall productivity. Moreover, uniform cooling improves part quality by reducing residual stresses and maintaining dimensional accuracy and stability (see Figure 2).

FIGURE 1. Mold cooling accounts for more than two-thirds of the total cycle time

FIGURE 2. Proper and efficient cooling improves part quality and productivity

Mold cooling system components

A mold cooling system typically consists of the following items:
– Temperature controlling unit
– Pump
– Supply manifold
– Hoses
– Cooling channels in the mold
– Collection manifold

The mold itself can be considered as a heat exchanger, with heat from the hot polymer melt taken away by the circulating coolant.

Figures 3 and 4 illustrate the components of a typical cooling system.

FIGURE 3. A typical cooling system for an injection molding machine.

FIGURE 4. A cooling channel assembly attached to the mold plates.