The following are some of the possible problems and causes that can occur during the edgebanding process.
Problem: The edgebanding pulls off easily by hand and the hot melt adhesive remains on the panel. The grid pattern of the glue application roller is visible.
Possible causes/tips: Not enough adhesive applied. The room temperature is too low. The edgebanding material too cold. The hot melt adhesive temperature too low. The feed rate is too low. Too little pressure is applied by the application roller.
Problem: The edgebanding pulls off easily by hand and the hot melt adhesive remains on the panel. The hot melt adhesive surface is totally smooth (edgebanding slips off).
Possible causes/tips: The board and/or edgebanding is too cold. Check the hot melt adhesive type. Check the application of the bonding agent.
Problem: The hot melt adhesive largely remains on the edgebanding.
Possible cause/tip: The temperature of the board material is too high as a result of previous processing (i.e., veneering).
Problem: The adhesive joint not closed (edgeband gluing machine).
Possible causes/tips: Too little pressure is applied. The adhesive is too cold. The edgebanding is either not pretensioned or reverse pretensioned. May need to increase the application temperature, preheat the board or increase the feed rate.
Problem: The glue joint is not closed (machining center).
Possible causes/tips: Too little pressure is applied. The edgebanding was fed in too cold and cannot be squeezed. The edgebanding material restoring force is too high. Increase heater power or reduce feed rate. Increase geometry or use a thinner edgebanding. The adhesive is not suited for use in machine centers or the adhesion under heat is too low.
Problem: Edgebanding is bonded only at the edges.
Possible causes/tips: Too little pressure is applied. The milled joint on the board is hollow. The edgebanding pretensioning is too high.
Problem: Inadequate bonding of the glued edgebanding at the face side of the board, or the edgebanding is chipped on the face side due to misaligned adhesive application roller.
Possible causes/tips: Not enough adhesive is applied due to a misaligned glue application roller; apply more adhesive.
Problem: Milling waves are visible.
Possible causes/tips: The feed rate is too high. The speed of the cutters is too low. Re-process with scrapers and buffing; cut against the feed. Increase the number of cutters on the router bit. Increase rpm.
Problem: On thick edgebanding, the color fades slightly in the milled areas (stress whitening).
Possible causes/tips: Warm up the milled area with a hot-air station (can be retrofitted). The scraper blade chips too thick. Rework on the buffing station. Reduce the scraper blade chip thickness (max. 0.1 – 0.2mm).
Problem: Evidence of stress whitening in radius during machine center processing.
Possible causes/tips: The edgebanding is fed in too cold. Increase the heater power or reduce feed rate. Increase the geometry or use a thinner edgebanding material.
Problem: Adhesive is stringy after application.
Possible causes/tips: Reduce the application temperature. Clean the gluing part. Test using a different adhesive.
Problem: So-called “mice teeth” in the joint.
Possible causes/tips: Apply more adhesive. Increase the application temperature. Preheat the board.
Problem: Breakout of longitudinal edges after cross- edging.
Possible causes/tips: Only format MDF board and use. Check the router for immersion depth. Reduce the material removal or use a different panel.
Problem: “Indentations” or “scratches” in the edgebanding.
Possible causes/tips: Clean the edgebanding draw-in. Clean the press rollers and spray them with a separating agent. Clean the scanning head; if this does not help then check the scanning head for damage and replace, if necessary.
Problem: Breakouts or smears at the edgebanding ends.
Possible cause/tip: Sharpen the crosscut saw. Ask the tool manufacturer for a suitable tool.
Problem: There are breakouts on the top and bottom edges.
Possible causes/tips: Reduce the edgebanding overhang. Acclimatize the edgebanding and boards one day prior to processing (over 18C). Increase the room temperature and prevent draught.
Problem: The edgebanding smears when copying.
Possible causes/tips: Reduce the number of blades. Control the rpm. Mill the edgebanding against the feed. Increase the feed rate.
Source: Surteco Canada Ltd., Brand: Doellken. For information call 800-461-0061 or visit na.doellken.com.
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