Decals can be either decorations or labels with instructions or information.
They are made of a pre-printed and pre-cut carrier, like a polymer film or
paper, with a pressure sensitive adhesive backing and a release sheet. The
release sheet is removed just before applying the decal to the surface of the
part to be decorated and the decal is then pressed into place.
As in adhesive bonding, the surface of the part must be clean and free of
oils, grease and mold release for a good adhesion.
Cleaning may be necessary. The abrasion, scratch, UV and chemical
resistance should preferably be tested on prototype parts, under
representative conditions.
The compatibility of the adhesive and the polymer film to the plastic must be
checked. Some adhesives for example, but also the plasticizers in PVC decals,
may cause environmental stress cracking in Xantar
polycarbonate and polycarbonate blends.
