Druckhaftung

Druckhaftung describes the resistance of a bonded interface to separation under applied pressure. In adhesive and coating technology, the term refers to the ability of a layer, film or coating to remain attached to a substrate when contact pressure is present. It is related to, but distinct from, other adhesion measures such as peel strength or shear strength. Druckhaftung focuses on the response of a bond to normal contact pressure and any constrained movement during loading.

Applications arise in areas where surfaces are pressed together during service, such as pressure-sensitive adhesives, protective films, labels, automotive coatings and electronic encapsulation. The concept helps assess whether a bond will withstand long-term contact pressures in real-world use.

Measurement of Druckhaftung typically involves standardized tests that apply controlled pressure to a bonded area and record the resulting load-bearing capacity or displacement until failure. Common approaches include lap-shear type tests, compressive or shear tests, and static or dynamic adhesion tests. Test conditions such as temperature, humidity, surface roughness and aging can significantly influence results.

Factors influencing Druckhaftung include substrate material and surface pretreatment, adhesive formulation and cure or crosslinking, coating thickness, environmental exposure, and mechanical cycling. Proper interpretation requires considering these factors alongside other adhesion metrics, such as tack, cohesive strength and environmental resistance, to obtain a complete performance picture.

Limitations: the term is domain-specific and may be used differently across fields. When reporting results, it is common to specify the exact test method and conditions to ensure clarity and comparability.

See also: Haftung, Klebstoff, Klebebänder, Oberflächenvorbereitung, Haftfestigkeit, Klebstoffprüfung.