Curing Polyurethane in Infrared Ovens

Question:

We have a job shop metal fabricating plant. We spray paint the products and cure the paint in an infrared oven. We have been asked to paint some plastic products on our paint line. The customer wants a polyurethane/acrylic paint on the product. Can we use our infrared oven to cure polyurethane/acrylic paint on these products? They are made of ABS and polypropylene. L. M.

Answer:

Polyurethane/acrylics and infrared go together like love and marriage, horse and carriage, etc. They were made for each other. The only words of caution are, make sure the products are free from mold release and oily soils and that the polypropylene will have to be pretreated possibly by flame treating. Infrared ovens can be used for curing most coatings. They have several advantages including rapid temperature rise and providing heat only when needed. They are turned off when not needed.

Furthermore, with the announced increases in natural gas costs, electric infrared technology may be the oven of choice for paint curing. Looking back to the energy crisis of the 1970s when natural gas was in short supply in some areas, due to uneven regional distribution, infrared technology saved several of my company’s plants. While we’re on that subject, my answer to the natural gas shortage is the Ajax direct-fired coal oven. When the temperature drops, throw another scoop of coal into the firebox (just kidding of course).