Hot-Melt PUR for Door Assembly

Thoughts on using hot-melt polyurethane adhesive for building doors. November 5, 2007

Does anyone have experience using PUR hot melt for cabinet door assembly? We currently assemble solid cherry, oak, maple, birch and poplar doors. We also assemble polyester wrapped MDF doors.

Forum Responses
(Adhesives Forum)
From Jeff Pitcher, forum technical advisor:
When trying to use HM PUR in assembly of cabinet doors, consider re-tooling your knives to allow a little looser joint. You can increase both production speed and joint strength with this adhesive, but if you don't allow for its thickness, you probably won't be happy with the open joint. Also, it's not widely known, but there are ways to automate the application process if your operation warrants it.

From contributor A:
Be sure to do your homework on PUR glues. While they offer some major advantages, there are some things to be aware of. I looked at PURs a couple years ago and it turned out that the pot life of the product on the machine was very short. If there was a sudden power outage earthquake, someone did not clean the spreader before lunch, or any one of a thousand other things happened, the glue would dry on the rollers and the machine would have to be disassembled to clean it and replace the rollers. Now this may not be an issue for you, but for us it was the nail in the coffin for PUR.

From contributor M:
This will give you the strongest door in the market, but your assembler has to move quickly to get it set in your door clamp. You also have to train your people on the equipment. If you can do these two things, you will love PUR. Also this means no squeeze out at the joint so you have no glue marks when you stain, which is why we went to this system.