It's plastic crate mould designer's responsibility to provide an adequate circulating system within the mould, and this section covers some fo the diffierent ways this can be achieved. In general, the simplest systems are those in which holes are bored longitudinally through the mould plates. However, this is not necessarily the most efficient method for a plastic crate mould.
When using drillings for the circulation of the coolant, however, these must not be positioned too close to the impression ( say closer than 16mm), this is likely to cuse a marked temperature variation across the impression, the layout of a circuit is often compliated by the fact that flow ways may not be drilled too close to any other hole in the same mould plate.
It will be called that mould plate has a large number of holes or recesses, guide pillars, guide bushes, sruce bush, inserts, etc.