Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


Need Help Selecting an Appropriate Material

Need Help Selecting an Appropriate Material

Need Help Selecting an Appropriate Material

Hi guys, I am designing a couple of injection molded plastics parts that have to slide across each other and I'm concerned about the coefficient of friction between them.  The two parts will be molded from the same material although I have not decided on a material yet.  Does anyone know where I might be able to find information about the coefficient of friction between various injection molded plastics?  

Thank you,

RE: Need Help Selecting an Appropriate Material

Try the IDES/Prospector database. They have a free version that will search for mechanical properties.

Rick Fischer
Principal Engineer
Argonne National Laboratory

RE: Need Help Selecting an Appropriate Material

The IDES database is a good source for base properties. In general a material with a low surface energy (HDPE, PP, PTFE, Delrin etc) will have low frictional coefficients. High surface energy materials like urethane and PPO will have higher coefficients. Truth is the surface 'texture', material hardness and applied force will have more significant impact.

RE: Need Help Selecting an Appropriate Material

One of the Golden Rules of Plastics Friction is... I am sorry... do not choose the same material for parts sliding on each other. This said, if you cannot afford to have 2 different materials then you'd may be able to have 1 grade for the 1st part and a slighlty modified grade for the 2nd one. In this case there will one material that will wear first. So you have to choose what parts should wear first.
As a general statement and taking a step back on plastic materials available for Injection Molding Technique I would say you'd probably find the POM or also called Polyacetal to be the best material to reduce friction. PA may also be good, but it should be compounded with additives reducing the friction. Some have small amount of PTFE, others Silicone oils or MoS2 inside.
Beside materials you'd consider part design of course: what is the surface of contact? Can you reduce it (in case you want the lowest friction possible)... And many other things to think about.

Thbaud Deleger
Empowering Polymers S.A.S.
Technical Writer & Polymer Consultant

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close