Testing acc. to ISO 8256: Plastics - Determination of tensile-impact strength
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Our test laboratory performs testing according to DIN EN ISO 8256, method A as an accredited test method for determining the tensile-impact strength of plastics. The tensile-impact test characterizes the behaviour of a material under rapidly applied tensile loading at a high rate of deformation. At FILK, specimen types 1, 2, 3 and 4 can be tested with pendulum energies of up to 4 J and at low temperatures down to −40 °C.
The method can be applied both to specimens produced from moulding compounds and to specimens taken from moulded products and semi-finished materials, including injection-moulded components, laminates and extruded or cast sheets. It therefore complements the mechanical characterization of plastics, elastomers and foils and forms part of FILK's testing portfolio for toughness and fracture behaviour.
Testing according to DIN EN ISO 8256
In method A, as performed by FILK, the specimen is clamped between a stationary fixture and a crosshead. When the pendulum impact tester is released, the specimen is subjected to rapid tensile loading until fracture. The impact energy absorbed by the specimen is determined and corrected for the energy components specified by the test method.
Depending on the material and test objective, different specimen geometries and either notched or unnotched specimens may be used. Tensile-impact strength is calculated from the energy required for fracture and the relevant specimen cross-section and is reported in kJ/m².
Applications of the test
Testing according to DIN EN ISO 8256 is particularly suitable for comparative assessment of thin or relatively flexible plastics under dynamic tensile loading. Typical test materials include thermoplastic and thermosetting moulding compounds, plastic sheets, injection-moulded parts, laminates and other polymeric semi-finished products.
The method can be used to investigate differences between materials, formulations and processing conditions with regard to their behaviour under impact loading. For anisotropic sheets, specimens may be tested in different material directions. The results are suitable for material comparison, production control and quality assurance, but are not intended as direct design data.
Related tests
For plastics suitable for impact-bending loading, FILK performs the Charpy impact test according to DIN EN ISO 179-1. For smaller specimens, bending and impact testing according to DIN 53435 is also available. For complementary characterization under static tensile loading, tensile properties of moulding and extrusion plastics can be determined according to DIN EN ISO 527-2.
