for the designer to create an optimum mould design, as he is no
longer free to change the mould design at a late stage. 
FEM-simulation of cooling system layouts is feasible from the
technical point of view, but most CAD-systems lack full integration
into the FEM software. This requires additional work, which usually
needs to be done by an FEM-expert. Furthermore, time for FEM
calculation still takes a long time (hours to days). The main issue
about FEM is that it does not design a good cooling system; it is
only showing the weak points. Depending upon the mould
designer’s knowledge and creativity, several loops are necessary to
get a result close to the optimum. For these reasons, FEM analysis
is only used for a small percentage of mould designs.
3.2   Cooling System Design 
Many designs of cooling systems are still done experience based
due to various limiting factors as described above. Such cooling
systems are not necessarily bad, but rarely optimal. Either the
mould designer “over-engineers” the cooling systems resulting in
high costs for mould manufacturing, or the system is having weak
points, which will result in slow mould operation due to long residual
cooling time. 
Figure 2 shows the importance of correct positioning of the cooling
lines (symbolized by a big circle). The small dots (2 x left / right, 1 x
centre) symbolize a control point on the mould surface. The centre
dot marks the “weak point” of the system. The mould surface at the
centre dot will always be warmer compared to the mould surface at
the outer dots. This is due to size and position of the cooling lines.
As the mould needs to be stable, it is unfortunately not possible to
have cooling liquid underneath the whole moulded surface.
Efficient cooling system design  is about reducing residual cooling
time. It is important to notice that performance of a cooling system is
driven by the weakest point. It is not always possible to reduce
residual cooling time to zero.  Depending upon the type of plastic
processed a small residual cooling time may be required in order not
to spoil mechanical properties or surface appearance of the moulded part. 
Figure 2: Importance of correct position of the cooling lines.
Designing a cooling system for a 3D-shaped part is a much more
complex task. The mould designer does not only have to pay
attention to geometric restrictions resulting from the shape of the
part, he has furthermore to keep space for functional elements such
as plastic injection (e.g. hot-runner system) and elements for
demoulding of the part (e.g. ejector pins, sliders, segments). The
shape and position of the sliders,  segments and ejectors can be
designed in different ways. Often sliders and segments need to
have a cooling system themselves. This means, the cooling system
is influenced by the functional elements and at the same time the
cooling system has influence upon their shape. 
Figure 3 shows a flow chart of the cooling system design process;
this process often requires an iterative approach.  摘要 
本文介绍了用于注塑模具设计节能工程的一个系统的方法。它支持工程师分析设计成果的注塑模具能高效节能地运行，同时该方法需要保证相应的最终产品的质量，保证该性能的生产过程能使用几年。信息和通信技术支持的系统的方法，提出了使工程师能够监控生产流程，从过去的设计学习，激发知识的设计，可以用更少的能源使用操作新的注塑模具。取得的经验和主要成果都被收集在汽车塑料零件生产中。 论文网
关键词： 设计节能制造;制造系统能源监测;基于知识的注塑模具设计 注塑模具设计英文文献及中文翻译(5):http://www.youerw.com/fanyi/lunwen_18373.html