Adhesiotestit

Adhesiotestit (adhesion tests) are procedures used to evaluate the strength, durability, and failure mode of bonds formed by adhesives between materials, or the cohesive strength of an adhesive layer. They provide quantitative measures of how well an adhesive joint resists forces encountered in service and help compare materials and bonding processes.

Common methods include peel tests, lap shear tests, pull-off (tensile) tests, and tack tests. Peel tests determine the force required to peel a bonded film from a substrate, typically reported as peel strength per width. Lap shear tests measure the resistance of a bonded joint to shear forces. Pull-off tests assess tensile strength at a defined interface, while tack tests evaluate the initial stickiness of an adhesive.

Procedures involve preparing test specimens, applying or curing the adhesive, and conditioning under chosen environmental conditions. Test machines apply controlled loads at specified speeds. Results are usually reported as adhesion or shear strength (units such as N/m or MPa) and energy to failure, along with the observed failure mode (adhesive, cohesive, or substrate failure). Environmental factors such as temperature and humidity, and surface pretreatment influence results and interpretation.

Applications span quality control and product development in sectors such as electronics, automotive, packaging, construction, woodworking, biomedical devices, and dental materials. Standards from organizations like ISO, ASTM, and EN guide test methods and reporting, but the choice of method depends on the intended service conditions and the materials involved. Limitations include the potential gap between laboratory test performance and real-world behavior, necessitating careful method selection and correlation studies.