Tensile tests on sewing thread are carried out according to DIN EN ISO 2062. In this example, screw grips are used and the strain is measured via the crosshead travel, with results shown in a typical force-strain diagram.
The grip-to-grip separation is 250 mm or 500 mm. The test speed is dependent on the grip-to-grip separation. With 250 mm grip-to-grip separation a 250 mm/min is used and with 500 mm grip-to-grip separation the required 500 mm/min. The maximum tensile force and the maximum strain are determined.
Pneumatic capstan grips are used when testing 2-ply thread to EN ISO 2062, with elongation measured via crosshead travel. The results are shown in a typical force-strain diagram. Due to the radii of the deflectors, a clamping length of 500 mm must be used.
The force reduction curve enables defined grip-to-grip separation during the test; thus direct extension measurement is not necessary during the test.
The force reduction curve reduces the tensile strength before end clamping. The specimen is held securely preventing jaw breaks and the test is performed according to the standard. The specimen should break in the free clamping length and not in the deflectors.
An extension measuring system is used for higher measurement accuracy without clamping influence. A mechanical measuring system should be used only when the risk of damage at specimen break does not exist.
Universal testing applications in a small force range up to 5kN. Tensile test, Compression test, Flexure test etc.