Examples of failures

phenomenon

reason

resolvent

remarks

The color fastness of composite membrane is not good

Poor adhesion caused by poor curing

1. The binder ratio is not suitable
2. When the glue is kept in storage, it will deteriorate when there is moisture
3. The glue is mixed with water and sprinkling essence
4. Softener in film, water is equal to glue reaction
5. Too little glue

1. Adjust the ratio of double liquid adhesive
2. Pay attention to the proper storage of the glue, the longest glue is no more than 1 year (sealed with iron cans)
3. Prevent foreign matters from entering the glue, especially water and alcohol
4. Increase the amount of glue

It has strong solvent smell and the glue is not dry

Increase drying temperature, air volume and more residual solvent

Reduce compound speed

Adhesiveness of adhesive

1. Use the expired double liquid adhesive, the glue solution has whitened and lost its viscosity
2. The film corona treatment is not good
3. The coating amount of glue is less
4. The use of surface printing ink, with the glue can not be bonded together

1. The double liquid type adhesive must be prepared with use, and the whitened glue cannot be used
2. Re corona treatment
3. Increase the amount of adhesive coating
4. Use composite ink

Test with wetting test

The composite coating of Al coating is easy to fall off

In vacuum Al plating, the plastic film has no primer (natural rubber) or special aluminum coating

In order to obtain good fastness of vacuum aluminum plating, a precoated special film should be used

The glue peeled off the aluminum coating

When the surface coating film is compounded, the coating layer is peeled off

The surface coating material has no compatibility with polyurethane

Change the glue used or change the surface coating film

After a period of time, the composite fastness decreased

1. Some additives seeped out from the film and acted on the adhesive, which destroyed the adhesive force
2. The contents of the package contain pungent, grease, spices and other ingredients, which will damage the adhesive force of the adhesive through the inner seal
3. The composite membrane is subjected to excessive heat or high temperature cooking

1. Select glue correctly or change film to prevent additive from seeping out
2. Select the inner seal material and thickness correctly to prevent the content from penetrating
3. Choose the film with good temperature resistance and cooking ink and glue with high temperature resistance

In particular, the temperature resistance of the polyurethane type of LDPE is higher than that of the polyester resin