Tensile strength, tensile stretch
The width-related breaking force (kN/m) and breaking elongation (%) of paper and cardboard are determined under tensile stress. They indicate the maximum force or elongation at which the material fails and the sample tears. During the test, a sample strip clamped on both sides is tested vertically (universal testing machine) or horizontally (tensile tester) at a constant test speed of 20 mm/min until it tears. From the recorded force-elongation diagram, further material characteristics such as the modulus of elasticity (MPa), the work absorption capacity TEA (J/m²), breaking force index (kNm/kg), etc. can be derived or calculated.
Tensile strength is one of the central physical values in paper production, especially for kraft papers. Important influencing variables are fibre type, additives, etc. Based on the strength properties, papers and boards can be designed for subsequent processing operations and a wide variety of applications.
- DIN ISO 3781 Paper and board - Determination of width-related breaking force after immersion in water