Hot Melt Troubleshooting Tips

Sure, melt adhesives are fantastic – they’re strong, efficient, and simple to apply. But when something goes wrong in the production line, what should you do? It’s not always obvious.

Fear not: we have prepared a rundown of a few relatively common application issues – and the most likely solutions to get your manufacturing back on track:

Adhesive Stringing

Sometimes referred to as “angel hair”, this refers to the thin strands of melt adhesive that may collect on your application equipment. If allowed to build up, stringing can diminish product quality or even force production downtime.

Most often, this is a heating issue. At lower temperatures, the adhesive will be more viscous and gum-like. Double-check against the adhesive manufacturer’s instructions to ensure that your equipment is set correctly – and that the temperature is uniform across all zones (tank, hose, and applicator). Distance between the substrate and applicator can also be problematic: you’ll ideally want them as close together as possible.

If the above isn’t applicable to your situation, or does not solve the problem, there may be more advanced configuration issues and/or assembly damage. In this case, contact the equipment manufacturer for further assistance.

Nozzle Dripdrips rolling

Leakage from the applicator nozzle generally indicates a mechanical issue that is preventing a full needle closure. Over time, the needle and seat will wear down and require replacement; this deterioration is a primary cause of adhesive drip. Alternately, it is possible that an obstruction in the applicator is impeding closure.

Give the nozzle and seat a thorough swabbing, and check the module for degradation. If the former doesn’t resolve the problem, replacing worn parts is most likely the solution.


Cleaning the applicator nozzle daily is critical. Small bits of dirt, debris, and melted adhesive can accumulate within it, leading to burnt and charred output. This, in turn, diminishes the effectiveness of your bonds.

Charring can also occur within the reservoir, damaging adhesives in the initial melting stage. This will usually indicate that the resting temperature is too high, possibly due to a setting mismatch or a faulty heating control. Prevent charring by keeping the reservoir temperature at appropriate levels, as determined by the adhesive manufacturer. If charring is already present in the reservoir, you’ll need to fully flush and scrub the tank of burnt debris – otherwise, the problem will likely recur even after resetting and/or replacing heat controls.

Contact Sure Tack Systems today for more information on melt adhesive equipment, or to discuss a customized solution for your business.