We make sport mouth guards for athletes that are custom fit to their individual mouths.
I was hoping someone may have some insight as to a sporatic problem we encounter with our products. The process involves two layers vacuum formed on each other with logos and pin-striping between.1) the first layer (base color layer) is not a problem. 2) The second layer is the sticker or paper logo and pin-striping 3) The outer layer is a clear strata (coat) that is heated and then vacuum formed over the whole unit (teeth model, base layer and logos)
Occasionally, we have a problem with the weld in that some times we get small bubbles which prevent the two plastics from welding in those areas. The kids may bite on these bubbles creating a breach between the layers and in effect ruining the unit. We are certain that the two layer of plastic (EVA Thermoplastic) are the same.
Questions:1) is there something to the grain that we should consider? 2) Is there a compound available that is non toxic, non carcinogenic and won't alter the color, etc that we can apply between the layers to encourage the weld? 3) Is there a compound available that we can use that in effect hardens the molar (back teeth) areas that is fairly thin and permanently welds to the unit without risk of falling off?
I would appreciate any help you may have in this matter.
Rick Sasseville Onsite Dental Services