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Plastics not subject to viscoelasticity (cold flow)

  1. May 31, 2018 #1
    I have been asked to find a machinable plastic (or dielectric) that will be subject to continuous loading (20 years) that will be subject to stress of appx 100 KPa at a max temp of 64C. 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 significant heat.

    I have read that 'cold flow' over a long time is primarily a problem with thermoplastic polymers 'only', but the information I have been able to pull up so far is very scarce and gives me little confidence about selecting a material. Not being in materials science, my ignorance is probably has me looking in all the wrong places.

    Can anyone shed some light about the cold flow being largely a thermoplastic problem and/or recommend a different source of viscoelastic data that I can use to find a plastic NOT subject to this long term phenomenon?

    All comments welcome!

    Best regards,

  2. jcsd
  3. May 31, 2018 #2


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  4. May 31, 2018 #3

    Thank you for taking the time to link me with the Curbell website. Absolutely the best I have seen for broad comparisons and drill down detail!

    Greatly appreciated!
  5. Jun 5, 2018 #4


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    Take a look at Phenolic material, sold as Bakelite and Micarta brands.
  6. Jun 7, 2018 #5


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    This compounder has a wide variety of different types. It may be worth a look.

    From previous work, polyphenylene sulfide, a semicrystalline polymer might be an option. Here's the variety of options for that material.

    A lot of physical properties are available for this polymer and others on that site.
  7. Jun 8, 2018 #6
    TomG & ChemAir,

    Both very good suggestions! I will research both.

    Thank you for your assist!!!

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