Important Rules of Thumb

Last time at work I was discussing with a good friend of mine, which rules of thumb we are still using in daily business and where did we learn them.

Rules, which make our daily engineering easier. Often applied, they get into our blood without thinking about them - like driving a car.

These following Rules of thumb, one dealing with polymer design in injection molding needs to know:

1. Part walls should be as thin as possible. Usually parts have a wall thickness from 1 to 4 mm. In case you want to have a wall thickness <1mm, consider processing techniques like expansion injection molding.
2. The walls of your part need to have the same thickness all over. Changes in wall thickness always have the risk of mass agglomeration.
3. When having corners on the part, use radii on them to have a good filling profile.
4. When designing parts with ribs, they should be put in the injection flow direction.
5. Take care that you use enough draft surfaces. After injection molding you want to be sure that you get the part out of the machine without deformation.
6. Your parts should not have undercuts.

This is by all means no complete list. This list can be continued with some more basic rules. Feel free to add!

Greetings

Herwig