Preventing solid edge delamination

What can be done to keep solid edging from coming off particleboard? June 6, 2001

13 mm solid edging, which had been pre-primed and looked good off of the machine, is now coming off the particleboard, leaving the adhesive attached to the particleboard, but no transference to the edge. What should I do to ensure this doesn't occur again, and can anyone suggest a repair method now that the shelving is on site?

Forum Responses
You probably have a real problem. Edge delamination (I am assuming it is a lumber band applied with an edgebander with EVA glue) on a bander can usually be cause by the heat being sucked out of the glue by the core and the longer time and more pressure it takes to glue a big stick. Try increasing your glue temperature slightly, put a heater on to heat up the core edge before it gets to the banding unit, think about cutting a tongue and groove on the parts! About the parts on the job, good luck. We have all had that happen--no easy fix.

Solid wood edges are a real challenge. Your problem can be solved in different ways.

Check the following:
- The moisture content of you lumber bands should be 6-8%.
- Use a rough sandpaper to increase the roughness of the lumber bands, then the hot melt will have better adhesion.
- Use max heat in the glue, even preheat the lumber with IR or hot air blower. Run machine at max speed. The glue will still be hot when the two substrates get in contact.
- Check the primer. Most people use PVAc glue. The PVAc adhesive is not compatible with the EVA hot melt.
- Simply switch to a Polyolefine hot melt (APAO). In general, they are much more aggressive in their tack. You do not need primer.