×
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

Annular snap in PP

Annular snap in PP

Annular snap in PP

(OP)
I'm designing a consumer product involving an assembly joined by an annular snap fit. (The OD of the male annular ring is approx. 14mm so it's not a small part) The client is dead set on using Polyproplylene for all the parts in the assembly however I'm concerned that the snap will wear prematurely given the soft nature of PP. Will the snap fit be more effective if the male component is harder than the PP part is snapping into? If so, what engineering thermoplastic would you recommend? (keeping in mind that it needs to be a food-grade material).

Thanks in advance!

RE: Annular snap in PP


I think a lot more info is required here:

e.g. No of operations, snap hold parameters, is the PP Homo/Co polymer, and so on ad nauseum...

Have you googled for "Snap Fits in Polypropylene" or spoken to the PP manufacturers - they've usually got white coats standing around not doing much.

They too though, will need a lot more information.

Cheers

Harry

 

www.tynevalleyplastics.co.uk

RE: Annular snap in PP

I fully support all that Harry says.

In addition I very much doubt PP will fail because it is soft. It may fail for lack of flex mod or tensile or creep, but lots more info is required, including the environment of use.

Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules
 

RE: Annular snap in PP

Check out Designing Plastic Parts for Assembly book at Amazon. It has step by step calculations for annular snap fits and many other types.

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