Hot Melt Troubleshooting: Fuming / Charring

Fuming and charring are among the most disruptive issues faced on hot melt adhesive lines. What often starts as a slight smell or light smoke can quickly turn into a serious production problem—one that affects bond strength, glue pattern consistency and, ultimately, line efficiency.

When hot melt begins to overheat or sit at temperature for too long, the adhesive starts to degrade. As it breaks down, two things happen:

1. Bond performance drops

Degraded adhesive loses its ability to wet out and grip the substrate. This can lead to weak bonds, pop-opens and increased rejects.

2. Char particles form and circulate

As the adhesive carbonises, it creates small blackened particles that move through the tank, hoses and nozzles. These fragments eventually block filters and application heads, resulting in mis-fires, uneven beads and unplanned stoppages.

Left unchecked, charring leads to recurring downtime, higher maintenance costs and wasted materials—yet most causes are preventable once identified.

To help operators and engineers diagnose the early signs and stop the problem at its source, we’ve created a dedicated Hints & Tips Sheet on hot melt fuming and charring.

Whether you’re dealing with frequent nozzle blockages or you simply want to prevent a future failure, this guide is a quick and effective way to get your system back under control.

👉 Get Your Free Hints & Tips Sheet

Fill in the contact form to receive your copy and start reducing charring-related downtime today.

If you’re facing persistent issues, our adhesive experts also offer a free Discovery Session to help diagnose and resolve the problem at its root.