Hot melt held too hot or too long oxidizes and crosslinks into brown or black lumps that flake off and clog filters and nozzles. Running tanks well above the recommended temperature, leaving them on through idle shifts and topping up instead of turning over the adhesive all speed charring. Char particles in the bead cause skips and contaminated product.
Nozzles keep plugging with char, the tank's been idling at 400 all weekend. Drain and flush it.
Also heard as
- charring
Related terms
Hot melt
A solid thermoplastic adhesive melted in a tank or gun, dispensed hot and set within seconds as it cools.
Angel hair
Fine threads of hot melt that string off the nozzle and drift across machines and products.
Purge
To run adhesive through a mixer or dispense valve and discard it, clearing old, unmixed or off-ratio material.
PUR
Polyurethane reactive hot melt, applied molten like a hot melt, then moisture-cured into a heat-resistant bond.