Glue Adhesion Issues with 3mm PVC Banding Issue

Troubleshooting a problem where edgebanding doesn't stick down along the centerline of the strip. September 15, 2011

I find that when I apply 3mm banding, I'm only getting good adhesion along the edges, not the middle. When I pull a piece of banding off, looking at the back of the banding, there's a 1/8" to 3/16" strip of glue along each edge, but little to none in the middle, between these strips.

Taking some loose, unapplied banding, if I flex it in the same manner that it flexes when it's applied by the pressure roller, the back of the banding isn't flat - it bows out slightly in the middle.

I've increased pressure on the pressure roller, and increased glue dosage, but am still not getting a complete bond. Anyone had a similar experience? Bander is a Brandt KD-55.

Forum Responses
(Cabinetmaking Forum)
From contributor C:
Just a thought. Last year during winter I had a job requiring some 3mm PVC on melamine. I ran it and noticed that some pieces had actually come off the ends (curled off). I started to think this is why some machines heat the banding and substrate before banding (to counteract force of curl of cold PVC in a roll). Still don't really know if that is why. I decided to reverse the roll of banding that fed into the machine. Magic! It worked much better.

From the original questioner:
I should add that the glue line on the panel edge is solid; the banding is just not contacting it down the middle.

From contributor G:

I would suspect the banding has cupped. Maybe old stock? Have you tried another brand?

From the original questioner:
The banding has cupped, and that is what's causing the problem. I've had the same issue with several rolls/different colors.

From contributor G:
Does your bander have pressure adjustment on the pressure roller? If so, you could try to increase the pressure. Other than that, maybe increase the thickness of glue application or try another manufacturer of edge tape.

From contributor L:
We've had the same problem. Only good solution is to get good banding. Even if your bander manages to press it flat, there is so much spring back in 3mm that it will pull loose in the middle. We've got an industrial level bander and it won't do much better than a lighter bander. It isn't the bander!