bcavender
Electrical
- May 31, 2018
- 104
I have been asked to find an economic, machinable plastic (or dielectric) for a continuously loaded application (20 year life) at a stress of appx 0.1 MPa at a max temp of 50C. While not a high speed or high energy situation, it is a rotating, close clearance application and the material cannot expand from its original dimensions without creating a potential frictional failure that could generate unacceptable heat.
Initial stress here isn't great, but I have read that 'cold flow' over a long time period can become a significant percentage of the initial geometry. The information I have been able to pull up so far is very broad and gives me little confidence about selecting a material. Not being in materials science, my ignorance of creep is probably has me looking in all the wrong places.
Can anyone shed some light about the cold flow being largely a thermoplastic problem (if true at all) and/or recommend a different source of viscoelastic data that I can use to find a plastic NOT subject to this long term creep phenomenon and point me into a productive direction?
All comments welcome!
Best regards,
Bruce
Initial stress here isn't great, but I have read that 'cold flow' over a long time period can become a significant percentage of the initial geometry. The information I have been able to pull up so far is very broad and gives me little confidence about selecting a material. Not being in materials science, my ignorance of creep is probably has me looking in all the wrong places.
Can anyone shed some light about the cold flow being largely a thermoplastic problem (if true at all) and/or recommend a different source of viscoelastic data that I can use to find a plastic NOT subject to this long term creep phenomenon and point me into a productive direction?
All comments welcome!
Best regards,
Bruce