Coatings Application

Q. I read your article “How are Coatings Applied” in the 2000 Products Finishing Directory and Technology Guide and would be interested in speaking with you regarding the best method to apply coatings.

I work in the Technical Center for a company manufacturing gasket materials. We are doing preliminary research into a new type of gasket material. I am looking for someone familiar with coating application techniques. I am hoping you may be able to help guide us on what coating methods to consider as we continue to scale our idea from the laboratory to production.

When you have a chance, would you e-mail or call me so we can see if you might be the right resource for us. D. D.

 

A. Your question is almost in my area of expertise. Once upon a time, I developed a highly thixotropic sprayable epoxy insulating coating for electrical bus bars that was applied 1/4-inch thick in one coat using a gear pump spray gun that was developed to apply sanitizable coating to brewery walls and floors. Since present day gaskets are applied to container closures as a coating, I will address your question.

What I envision, without ever seeing it, as the present method for applying gasketing materials to pop (tonic in Philly and soda in NYC) bottle lids as well as jar lids, is a transfer or stamping process. A rubber or elastomeric stamp would be dipped into the wet gasket material and then pressed onto the lid applying the uncured gasket. If that is not the case, that’s one you can try.

Another method to consider is extrusion. The wet gasketing material would be pumped to an extrusion head machined to apply the proper shaped uncured gasket to the lids. In this case, you will need gear or piston pumps to feed the extrusion dies and meter the correct amount of fluid for each gasket. Suppliers of this kind of equipment are listed on pages 366 of the Products Finishing 2007 Directory and Technology Guide under Pumps, paint, plural component metering (www.pfonline.com/suppliers.html).