repeytymistestejä

Repeytymistestejä is a Finnish term referring to tests that measure a material’s resistance to tearing. The tests determine the force required to propagate an existing tear or notch in a specimen, providing a quantitative measure of tear strength or tear resistance. They are used in quality control, product development, and standards compliance across industries such as paper, textiles, packaging films, and plastics.

Common testing approaches include pendulum-based Elmendorf tear tests for paper and board, which record tear resistance in newtons; and tear tests for textiles and flexible materials (such as the trouser tear test and the single-edge tear test) that measure the force needed to propagate a tear under controlled speed and geometry. In plastics and laminates, tear strength or tearing energy can be reported, sometimes in N/m or J/m^2, depending on the method.

Tests typically involve preparing specimens with a predefined notch or pre-crack, conditioning the material (temperature and humidity), selecting a test geometry, and applying load until tear propagation occurs. Results are affected by orientation, thickness, speed, and notch size, so standardized methods specify these parameters.

International standards from ISO, ASTM, and TAPPI provide methods for specific materials, enabling comparison across suppliers and products. In Finland, repeytymistestejä support material selection for packaging, textiles, and paper products, contributing to reliability and safety in consumer and industrial applications. The term is primarily used in Finnish technical literature and quality-control contexts.