Haftmitteln

Haftmittel, or adhesion-promoting substances, are materials designed to improve the bonding between two surfaces or layers. They function by increasing wettability, creating chemical bonding sites, or forming a roughened microstructure that helps mechanical interlocking. Haftmittel may be formulated as primers, adhesion promoters, coupling agents, or specialized bonding agents. Common families include solvent-based primers, waterborne primers, silane coupling agents, and resins tailored to interact with specific substrates.

In coatings, construction, electronics, and textiles, Haftmittel are applied to a substrate before the next layer, adhesive, or repair material to enhance adhesion and reduce delamination. Silane-based Haftmittel, for example, can chemically bond inorganic surfaces to organic polymers. In nonporous substrates like glass and metal, adhesion promoters improve wetting; on porous materials such as concrete, wood, or brick they enhance mechanical interlocking.

Selection depends on substrate compatibility, environment, temperature, and mechanical demands. Requirements often include chemical resistance, flexibility, and appropriate curing behavior. Safety considerations include solvent content and potential health or environmental hazards; many Haftmittel require proper ventilation and protective equipment.

Testing of Haftmittel typically involves adhesion tests such as pull-off or cross-cut tests, as well as surface-energy measurements and substrate compatibility assessments.