Slow-curing sealant is a common hiccup in insulating glass (IG) production, delaying workflows and risking quality. Fortunately, it typically stems from just two issues—both easy to resolve.

One cause is reactions between different sealants. Mixing types (e.g., new primary with leftover secondary from another brand) can turn extruded sealant dark black and prevent curing. Fix: Purge the extruder with solvent (per supplier guidelines) and use matching sealants.

More often, the issue is too little black sealant (the curing agent). Equipment drift (like off-calibration booster cylinders) can reduce its ratio, slowing or stopping curing. Fix: Adjust the cylinder to increase black sealant, then check for a 4–6 hour “tack-free time” (per specs).

Pinpointing these causes lets you act fast, keeping your IG line efficient and ensuring strong, durable seals.

We are producing IGU lines, Insulating Glass Machine, Insulating Glass Argon Gas Filling Line, Insulating Glass Sealing Robot Line and all kinds of Special-Shaped Glass Sealing Robot, Insulated Glass household appliances with wire sealing machine.We have our own technology to supply you Customizable IGU machines and lines.

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