Adhesion strength

Adhesion describes the bonding of paints, printing inks, adhesives, barrier layers or other layers to plastic surfaces. It is influenced by various factors:

• Adhesion through the ratio of surface energy between plastic and coating
• Mechanical anchoring through cavities and rough surfaces
• Molecular diffusion between coating and plastic
• Chemical bonding between the molecules
• Electrostatic attraction due to surface charges, which is influenced by humidity.

The test method according to EN ISO 4624 measures adhesion. An adhesion failure (A) indicates a weak point between coating and substrate. In the case of a cohesion failure (B), the bond to the substrate is stronger than the coating itself.