What are the disadvantages of using hot melt adhesive for self-adhesive label paper

The disadvantages of using hot melt adhesive on self-adhesive label paper are mainly reflected in the following aspects:

1. Limited heat resistance

High temperature easy failure: hot melt adhesive is a thermoplastic material, and its products will melt flow or creep when the temperature of the use environment is close to or higher than its softening point. Because hot melt adhesives are limited by common thermoplastic elastomers (such as SBC, EVA, APAO), their softening point is generally not higher than 100 ° C, so it is not suitable for high temperature and long-term use in the environment. Under high temperature conditions, the hot melt adhesive may soften or even melt, causing the self-adhesive label to fall off or fail.

2. Poor solvent resistance

Soluble in organic solvents: most of the thermoplastic elastomers and viscosifiers used in hot melt adhesives are easily dissolved by organic solvents (such as toluene, xylene, etc.) or plasticizers (such as mineral oil, naphthenic oil, etc.). When the self-adhesive label comes into contact with these solvents, the composition ratio and viscosity of the hot melt adhesive may gradually change, and eventually lose viscosity, resulting in the label falling off.

3. Sensitive to temperature and humidity

Temperature affects the bonding effect: the bonding performance of hot melt adhesive is greatly affected by temperature. In high temperature environment, hot melt adhesive may soften or even melt; At low temperatures, the viscosity of hot melt adhesives may increase, making bonding difficult. Therefore, when using self-adhesive labels, it is necessary to strictly control the ambient temperature to ensure its good bonding effect.

Humidity affects adhesion: A high humidity environment may affect the bonding properties of hot melt adhesives. Hot melt adhesives may absorb moisture from the air, resulting in reduced adhesive strength. In humid environments, the application of self-adhesive labels may be limited.

4. High cost

High production and use costs: the production process of hot melt adhesive is relatively complex, requiring special equipment and processes for production. In addition, in the process of use, it is also necessary to be equipped with special heating equipment and sizing equipment, such as hot melt guns, which increase the production and use costs of self-adhesive labels.

5. Limited application range

Manual coating effect is not good: hot melt adhesive with manual coating effect is not good, waste glue and difficult to control, need to be equipped with special equipment to melt and sizing. This limits the application range of hot melt adhesive in the field of self-adhesive labels to a certain extent.

Not suitable for all materials: Hot melt adhesive can not be attached to some specific materials, such as PVC material, because its internal plasticizer will gradually migrate to the surface and be absorbed by the hot melt adhesive, causing the hot melt adhesive to lose its viscosity.

In summary, when using hot melt adhesive, self-adhesive label paper needs to pay attention to its heat resistance, solvent resistance, sensitivity to temperature and humidity, cost and application range. In practical applications, appropriate adhesives need to be selected according to specific needs and conditions.