Where the
world gathers for metal finishing
Q&As since 1989


-----

Tinplate coating peeling off

Hello- I have a big problem.

We order candy tins from China that we use to package candy/mints. The bottom half is coated with a white laminate that is adhered after applying a clear coat that promotes adhesion.

Once previously the coating started peeling off on the corners (tin is rectangular with round corners). Not too much peeling before packaging with hard mints (includes passing though 300 degree heat tunnel for 4 seconds for shrink wrap) but bad peeling after. Tin manufacturer redid shipment and no further issues at all with subsequent lots.

Problem has surfaced again. Same exact situation - can see minimal edge or none on new tins and after packaging the peeling starts. Is there a reaction happening? What could be the problem with tinplate and coating? Problem had been resolved once - thought to be lack of clearcoat on tinplate.

What is problem and why is this happening?

Dale Nemecek
Mfgr/packager - Scotts Valley
2007

---

Perhaps use preshrunk material for the laminate.

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
2007