Root Causes

Excessive lamination pressure, over-tension, over-tight winding, and uneven initial roll-up.

Solutions

1. Decrease lamination pressure or increase the lamination gap.
2. Adjust the system to reduce tension appropriately.
3. Trim the leading edge of the roll to ensure straightness, then flatten and fasten it securely with double-sided adhesive tape.

1. Inadequate adhesive coating weight

Increase the adhesive coating weight to meet required specifications

2. Film-related defects

Perform tests on the film to verify surface oiliness and hydrostatic pressure performance

3. Fabric-related defects

Conduct waterproof rating testing on the base fabric

4. Excessively high processing temperature

Reduce the processing temperature and conduct trial runs to validate performance

1. Insufficient adhesive coating weight

Increase the adhesive coating weight by using a coating roller with a higher capacity (or roller with big dot) to meet the required specification.

2. Inadequate lamination pressure

Adjust and increase both the lamination pressure and winding pressure to the optimal operating levels.

3. The adhesive coating roller was not thoroughly cleaned

Thoroughly clean the adhesive coating roller using a clean, suitable solvent to remove all residual adhesive and contaminants.

4. Inadequate curing time

Extend the curing time according to ambient conditions: 8–12 hours in summer, and 12–24 hours in winter.

Improper adhesive coating roller matched for thin fabric, excessive laminating pressure, fast running speed and overly thin adhesive viscosity.

Select a suitable adhesive coating roller; reduce and adjust pressure to proper value; slow down the laminating speed; lower the adhesive melting temperature to 110-130℃.

Insufficient initial adhesion

Increase glue application volume, reduce gluing temperature, and switch to adhesive with higher initial adhesion.

High moisture content in the air causes reaction between PUR adhesive inside the tank and moisture.

Replace with summer-specification adhesive in a timely manner. April to May is the critical replacement period.

1. Improper gluing temperature (too high or too low)
Excessively high temperature makes PUR adhesive penetrate excessively into the substrate, cutting down the quantity of effective bonding glue.
Overly low temperature will raise adhesive viscosity and weaken substrate wetting performance. Only superficial bonding is formed without molecular penetration, leading to direct delamination upon peeling.
2. The adhesive gets surface dried before lamination.
3. Insufficient pressing time and pressure.
4. Substandard curing conditions with excessively low humidity or temperature.
5. Insufficient glue coating amount.
6. Low surface energy of substrates (PP, PE)

The adhesive cures and becomes insoluble.

Crystallization and clogging occur when the adhesive contacts moisture and solidifies. Keep the whole system fully sealed during operation. Clean the nozzle promptly after use, and never store the adhesive in an open state. Severe yellowing is caused by high-temperature aging.