How to achieve a good injection mold design?

Mold design is a start of success molding processing; an optimum mold design is aim for the best molding performance.

To achieve a good mold design, you need to take elements into consideration as below:

The most optimum mold cavities layout.
Proper mold base size and guiding way.
Provide reasonable injection mold flow and filling performance.
Use reasonable shrinkage factors ,especially parts in long length).
Study the part design in 2D, the tolerance required determine the way you design and machine it greatly.
Adequate cooling layout.
Proper ejection distance, de-molding way.
Minimum injection molding cycle time and as less as possible secondary works such as de-gating, drilling.
Appropriate gating location, welding line position accepted by the customer.
Minimum clamp force requirements, as less as possible injection pressure requirements. (the injection molding machine required smaller, the injection molding cost lower)
Adequate venting as well as reliable sealing to avoid flash occurs.
Minimum scrap rate (most important factor to influence the real cost of injection molding process).
Proper selected steel and heat treatment, just fit the demands of the customer ( otherwise it would be called "over-designed").
Watch out the particular features such as sliders, lifters, make sure all the mechanisms designed perform well
Study the part design in 2D, the tolerance required determine the way you design and machine it greatly
Minimum clamp force requirements, as less as possible injection pressure requirements. (the injection molding machine required smaller, the injection molding cost lower).

A lot of defects occur frequently can be minimized by good mold design:

Flash
Sink mark
Surface defects
Short-shot
Unbalance filling
Many other common defects

A good mold design can reduce the manufacturing cost as well as shorten the delivery time, it also increases mold quality, productivity and provides best performance stability.