Sealing Plastics

Q. Through the course of my study, I have become interested in methods of sealing/lacquer with powder coating, especially of plastics. This is not yet well known in my country of Belgium.

I’m wondering if you can provide more information about this process? Is this method also suitable for the food industry? For example, to give a plastic spoon a chrome look? I would like to experiment with it and would be very grateful if you could give more details as to which powder to use, how to use it and where I can acquire the powder. V.A.

 

A. Powder coating of plastic has limited application. The plastic must be able to withstand temperature of at least 250°F to melt the powder before UV energy can be used to fully cure the material. Most plastic silverware is made from materials that would never withstand the melting temperature of the powder coating.

Many powder coatings are formulated for use in the food industry. In the U.S., these materials have FDA approvals, allowing manufacturers to use them in coating products that see direct food contact.

I am not sure if any of the UV-curable powder coatings used on plastic substrates have these food-use approvals in place. Obtaining these approvals is very time-consuming and expensive, so powder formulators typically do not submit anything for approval for which they have not already established a market.

You will probably need to have your utensils colored in the base plastic, like most other suppliers. Powder coating is just not very cost-effective or practical, given the hurdles the coating must clear to be rated for direct food contact.