TENSILE STRENGHT OF COMPOSITE MATERIALS DURING THE LASTING PROCESS

Abstract

The manufacture of footwear suppose tensile loads during the lasting process of uppers. The paper presents the results of the study for the materials’ behavior under tensile stress. To this intent, the breaking strength and elongation at break have been analyzed when the tensile load of 10N/mm2 is applied to flexible materials and leather. The behavior under the tensile stress of 10N/mm2, tested in order to determine the materials deformability during the lasting process, has been observed using tensile testing machine SATRA (STM 466) and its software providing quick and simple-to-understand load-distance graphics. The elongation corresponding to a tensile stress of 10N/mm2, concluded from the graphics, is useful for characterizing the mechanical properties of materials as the lasting process involves stresses of about 7-8 N/mm2. It was found that the selected materials for the present study can be used for sport footwear manufacture combined with leather and spacer fabrics. In the case of composite materials, the elongation at break is smaller than for the simple materials, tested individually. Among leathers, the biggest values of the maximum tensile force at breaking were obtained for nubuck leather, followed by box calf leather.

Keywords

• Tensile
• breaking
• elongation
• leather
• spacer fabric