Smart questions
Smart answers
Smart people
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Member Login




Remember Me
Forgot Password?
Join Us!

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips now!
  • 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!

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

Donate Today!

Do you enjoy these
technical forums?
Donate Today! Click Here

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.
Jobs from Indeed

Link To This Forum!

Partner Button
Add Stickiness To Your Site By Linking To This Professionally Managed Technical Forum.
Just copy and paste the
code below into your site.

stony99 (Structural) (OP)
28 Apr 10 22:48
Hello,

Wonder if any of you has an idea on how this could be resolved.  We produced color for Polyrpopylene Chairs that were injection molded for outdoor use.

The formula has orange and yellow colorants, but the orange is fading within 2 months and the color is changing.The yellow pigments are very stable and will last for 3 years outdoors but the orange fades.

How can something like this be re-solved?
John  
patprimmer (Publican)
28 Apr 10 23:13
Choose light fast colours.

Use UV stabilisers to prevent surface degradation of the polymer.

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
 

stony99 (Structural) (OP)
28 Apr 10 23:18
Pat,

Thanks for the response. We used .5% UV additive and that is protecting the polymer, but one of the pigments is fading quickly.

So the color is changing from an orange shade yellow to a greenish shade of yellow.

The yellow pigments that were used are very stable and resist fading. Unfortunately, we did not know that the orange pigment would fade so quickly outdoors.

The chairs are installed outdoors and the change in color is noticable.

Not sure if any one has ideas on how something like this could be resolved.

Thank you for any thoughts.

John  
patprimmer (Publican)
29 Apr 10 4:55
It cannot be resolved in existing mouldings.

Discussions with your colour supplier should be frank and to the point about your existing problem and your future expectations. It is up to them to formulte the colour.

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
 

Pud (Mechanical)
29 Apr 10 5:28

Oh, those were the days - when cadmium based pigments were available!

As Pat wrote, I would suggest you talk to your colour supplier and tell them what you need. Iirc, these days reds are tricky (expensive) to get good UV resistance.

H
 

www.tynevalleyplastics.co.uk

stony99 (Structural) (OP)
29 Apr 10 6:42
Thanks H & Pat,

It was my company's fault since we should have known not to use this particular Orange pigment for an outdoor application.

What would we have to do, arrange to have the 10,000 chairs un-installed, and then supply new resin re-matched with a new Orange that won't fade?  The only good thing is that they Yellow pigments used in this will easily last 3-5 years outdoors. So once the orange fades out, the color will remain stable. Its just that the difference when the orange fades is very noticable.

Any ideas or thoughts are appreciated.

Thank you,
JP
MacGyverS2000 (Electrical)
29 Apr 10 6:46
Stick them all out in your parking lot for a few months until they fade to a stable color, then sell them?

Dan - Owner
http://www.Hi-TecDesigns.com

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