Common faults and treatment of dry compounding of

Common faults and treatment of polyurethane adhesive dry compounding

fault phenomenon

phenomenon description

solution

bubbles appear in the composite film

the temperature of the drying channel is too low, leaving residual solvents

● improve the drying channel Adjust the air volume and wind speed

the moisture content of the solvent is too high

● control the solvent content to be less than 0.2%

the environmental humidity is too high

● keep the environment ventilated and dry

the composite film is wrinkled

rewinding this button controls the quick oil return valve or the unwinding tension is inconsistent, too large or too small

● adjust the rewinding Unwinding tension

unbalanced pressure or uneven pressure of the composite roll

● adjust the composite roll to make it in balance

filling of the composite roll or imbalance of the guide roll

● adjust the composite roll or adjust the balance of the roll search

the composite film is equipped with mechanical equipment such as levers, white spots

the environmental humidity is too high or the water content of the solvent is too high

● control the environmental humidity and the water content of the solvent

excessive residual solvent

● increase the temperature of the drying path or reduce the temperature of the drying path.The Slow speed

the mixing of adhesive is uneven

● the mixing is uniform

the amount of curing agent is too much

● the amount of curing agent is reduced

the composite film is still sticky after curing

the mixing of adhesive is wrong or the mixing of adhesive is uneven

● grasp the use conditions and process of adhesive correctly

the environmental humidity is too high, The water content of the solvent is too high

● control the environmental humidity and the water content of the solvent

incomplete curing

● increase the curing temperature or extend the curing time

the quality problem of the glue itself

● replace the glue

the peeling strength of the composite film is low

the glue amount is insufficient

● increase the working concentration and replace the rubber roller

the film is damp or the corona treatment fails

● replace the film or conduct corona treatment.

incomplete maturation

● properly extend the ripening time to avoid galling contact surface time

too high water content of the solvent causes the imbalance between the main agent and the curing agent

● control the water content of the solvent to be less than 0.2%

the packaging bag produces peculiar smell

the temperature of the drying channel is too low, and there is too much residual solvent

● increase the temperature of the drying channel and increase the air volume and wind speed

aromatic impurities (toluene, xylene) are contained in the dilution solvent

● improve the purity of the solvent

additive odor in the film

● exchange the film

the ink is not completely dry when printing,

residual solvent with high boiling point

● rewind the printed film through the drying channel again

the adhesive contains aromatic solvents

● replace the glue

low heat sealing strength

quality problems of the adhesive itself

● replace the adhesive

the amount of adhesive curing agent is too small

● increase the amount of curing agent

the environmental humidity is too high or the water content of the solvent is too high

.● control environmental humidity and solvent water content

The film is not cured

● extend the curing time

source: Huashi chemical