×
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

removing discoloration from pvb

removing discoloration from pvb

removing discoloration from pvb

(OP)
I have laminated 16 oz copper to a sheet of glass using Saflex pvb and the autoclave process.
I put this substraight through chemical etching using ferric chloride. This process has left the exposed pvb VERY yellow. Any suggestions as to what to use to remove the yellow and not delaminate my copper?
This is an artistic medium and not a manufacturing situation...yet.
Thank you for any ideas.

RE: removing discoloration from pvb

I dont know what PVB is, but I do know that Ferric Chloride creates permanent, horrible yellow stains.

When I was a kid I did some home PCB manufacture, the counter top that I spilt the FeCl onto was still stained 20 odd years later. (When it was removed and replaced.) I tried to clean it uncountable times with all kinds of cleaners, noen had any real effect....

Good luck.

RE: removing discoloration from pvb

Polyvinylbutyral is the material used for the inner layer of laminated safety glass used for automotive windshields.

Can you cut/grind the PVB?

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

RE: removing discoloration from pvb

(OP)
I will not be able to cut or grind the PVB.

RE: removing discoloration from pvb

I suspect that you will simply need to start over.

Either laminate an oversize piece and cut it to size after etching, or seal the edges before you etch.

RE: removing discoloration from pvb

Hi there,
from chemical point of view there is a small chance, if discoloration comes from Fe3+.
Try a reducing chemical like Sodium dithionite. It is sold (at least here in Germany)as "Entfärber" - discolorator - for stained textiles, used like a simple detergent.

But by my experience from making PCB in my electronic times before persulfates came up chance is very small, my fingers kept yelolow for weeks.

Regards Berti

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