How do I narrow down specific values when selecting a plastic for injection moulding?
My part is uniform in wall thickness and thins out where a hinge a present.
- Will not go under many cycles in its lifetime, however, needs to be rated for thousands of cycles
- The entire part is about as long as a finger and the hinge will displace minor distances (2-3 mm)
- Will have to operate in temperatures from -20 to 60 Celsius
- Applied forces are minor and not sudden
I have designed the hinge as follows:
I have the model in CAD and have run FEA to figure out stresses (ie. Von Mises). I have also 3D printed it in ABS, and it has passed vibration testing and performs as designed.
The criteria I have narrowed down based on matweb is:
- I need the hinge to bend easily, so it does not affect the entire product- a low flexural modulus
- As the plastic part is supported in one area, I need it to be able to withstand vibration testing. Therefore, sorting by the lowest density so that it does not collapse underneath its own weight
- Shore Hardness D of around 60 to 80, as I need the part to not be flimsy yet not too rigid
- Despite the hinge being able to bent easily, I need it to also return to its original form when it is not stressed- a high resilience
How do I go about determining specific values for the criteria? Are there other mechanical values I am neglecting?