When does glue lose its tack?

Common Situations in Which Glue Loses Tack

Loss in tack during use is often caused by a combination of the following factors:

1. Environmental Factors

Temperature: Excessively high or low temperatures can change the viscosity of the glue, causing it to lose its tack.

Humidity: Moisture in the air can penetrate the adhesive layer, disrupting the intermolecular forces between the glue and the substrate, leading to a decrease in adhesion.

UV: Prolonged exposure to UV light accelerates the degradation of the photosensitizer and weakens the adhesive.

2. Material Aging

With extended storage time, the polymer chains within the glue gradually crosslink or degrade, causing a natural decrease in tack.

3. Improper Use

Mismatched Formulation: When the polarity and surface energy of the glue and the bonded material do not match, the bonding effect will rapidly diminish.

Surface Contamination: Oil, dust, or water film can form a barrier between the adhesive layer and the substrate, directly leading to loss of adhesion.

Uneven Application: Too thin or too thick an adhesive layer, lack of pressure, or insufficient curing time can all lead to bond failure. 4. Chemical Factors
Solvent Evaporation: Some solvent-based adhesives react with moisture in the air after opening, causing the adhesive to harden and lose fluidity, ultimately losing its adhesiveness.
How to melt dried adhesive?
After the adhesive has solidified in the bottle or adhered to a surface, there are several possible "softening-dissolving" methods. The following describes common scenarios:

Safety Tips: When working with organic solvents, always work in a well-ventilated environment and wear protective gloves. Avoid burns and thermal damage to the substrate during heat treatment.