×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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

Jobs

Improving Neoprene Compression Set

Improving Neoprene Compression Set

Improving Neoprene Compression Set

(OP)
Is there any way to improve the compression set of molded neoprene parts? Any production methods that will improve compression set? The samples for compression set testing are taken from the molded parts. The neoprene itself passes compression set testing when the testing is done on molded "buttons" as per the applicable ASTM testing procedure - but the neoprene fails when samples are taken from the production part.

RE: Improving Neoprene Compression Set

Compression set in a compound depends on the state of cure, which is why this test is always carried out on buttons of a specified size.  If the part you are making is thicker than the button then the state of cure throughout the part will be different to that in the button.  Therefore the resulting compression set will be different.  The only way I can think of improving this property is to post-cure the parts for a given time at a given temperature (determined from the cure traces of your compound(s) to increase the state of cure and, thus, the compression set resistance.

RE: Improving Neoprene Compression Set

(OP)
Thank you for your reply!!

If we post-cure at the temperature and time recommended by our Custom Mixer, will this adversly affect tensile and elongation properties? How about Shear Modulus?

Any help is appreciated.

RE: Improving Neoprene Compression Set

Post curing will affect the tensile and elongation, but how depends on the initial state of cure. Increases in hardness, tensile and drops in elongation are common when postcuring)

Be aware that post curing may change dimensions as well.

If you can't increase cure time/processing time or raise moulding temp slightly then you may want to ask the material supplier if they can speed the material up a bit.

Do you cut your product down for testing?
We use a splitting machne similar to the following (look up PMF fortuna splitting machines) quite expensive but excellent for cutting down rubber products for testing.

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!


Resources