The design of injection moulds consists of six main
processes, namely, (1) splitting of geometry, (2) slit-line
definition, (3) injection point determination, (4) moving
parts design, (5) ejector pin design, and (6) cooling system
design [10]. Figure 2 shows in detail the different tasks that
are undertaken during hits phases. During the geometry
splitting phase, the product to be moulded is virtually
divided in several parts. Once this is done, the split line is
defined to identify the core, cavity and eventual sliders of
the mould. The injection point definition consists of
defining the points were the mould will be filled in with the
hot the polymer. At this point, the mechanisms required for
moving the sliders are designed and the geometry and
places where ejector pins are located are fixed. Finally, at
the end of this process, the cooling system is designed.
Cooling design is of paramount importance for the
injection moulding process because it determines to a large
extend the final product quality as well as production time.
However, cooling design is done at the end of the mould
design process. As consequence, it is constraint by the
results of the upper design decisions, leaving small room for
optimal cooling systems. The major constraint imposed to
cooling design is the complexity of the mould geometry
after the first design steps have been worked out. Sliders,
ejectors pins and other mould moving parts constraint the
mould volume so much, that an optimal cooling is hardly
feasible. Therefore, from a design process point of view,
cooling system design can be improved by performing it
concurrently with the design of sliders