UV Inks On UV Powder Coating

Question:

I am the supervisor of the printing operation in our plant. I am searching for a UV ink that can be printed on a metal substrate powder coated with a polyester paint. Is there such an animal? Would a UV ink stick to a UV powder coating? C.N.

Answer:

As a general rule, UV curable inks will adhere to any substrate that can be adhered to by conventional inks. The difference between the two types of inks is curing mechanism. UV curable inks are formulated using resins containing photoinitiators and photoaccelerators that cause them to cure when exposed to ultra-violet radiation.

The same applies to UV curable inks over UV curable powder coatings. However, if either the paint or the powder coating has a slip agent on its surface, adhesion of any inks could be a problem. Slip agents such as waxes and polyolefins are added to provide mar resistance to a painted surface. If they are present, steps must be taken to remove them before overprinting or overcoating.