Interference fit of HDPE into HDPE
Interference fit of HDPE into HDPE
(OP)
I am trying to design a part that requires an interference fit of an extruded HDPE pipe .79" OD and .55" ID into a base of the same material. What is the rule of thumb for diameters and tolerances for an interference of plastic into plastic. I have formulas that would work for metals, but do not really apply for plastic. The elongation of HDPE is over 100%. Can anybody help me?
Thanks in advance,
lurks
Thanks in advance,
lurks





RE: Interference fit of HDPE into HDPE
The rule of thumb is really that whatever inteference fit you have, giving a particular strain, the stress will drop off with time due to creep. HDPE is poor for creep. Your best bet is for max interference commensurate with easy assembly and cross your fingers!
Note the stress will not drop off completely, but may be less than your design requires.
If the PE is cross linked, you will be a bit better off.
Cheers
Harry
www.tynevalleyplastics.co.uk
RE: Interference fit of HDPE into HDPE
You may also lose your original interference fit over time due to the effects of creep/cold flow.
Good luck.
Terry
RE: Interference fit of HDPE into HDPE
You might want to take a look at thermal welding, e.g. with an embedded heating wire.
Mike Halloran
Pembroke Pines, FL, USA
RE: Interference fit of HDPE into HDPE
Mike Halloran
Pembroke Pines, FL, USA