Tensile testing is a method of evaluating the mechanical properties of a material based on the force required to deform the material in a controlled manner. In this method, forces up to 200 kN and strains are recorded in the temperature range from -50 to 200 °C, which makes it possible to measure material parameters such as:
• Ultimate tensile strength
• Strength at break
• Yield strength
• Elongation at break
• Young’s modulus
• Stress relaxation rate
• Creep rate
Individual dynamic and static multi-step procedures can be designed and performed to evaluate the specific required properties of the materials. The tests can also be carried out under resistive or inductive heating with electric current or alternating magnetic field respectively, as well as in an aqueous environment. Besides elongation experiments, compression is also possible.

Test specimens can be:
• Bulk object up to 1 cm thick and up to 2.5 cm broad (solid material, foam, gel, etc.)
• Film down to 50 μm thick
• Fiber down to thickness of the 10 μm order
The testing length can go down to 5 mm, while 20 mm is considered to be standard. Please be aware the approximately 5 mm from both sides of the sample would be required for its fixation. For fibers thinner than 50 μm, the minimal length is 10 cm. Typically, a series consists of minimum 3 samples and the results are averaged. For specific measurements 1 sample could be sufficient. Tensile testing is not limited to polymeric materials and can also be applied to e.g. metals. The packaging of the specimen must take into account any sensitivity against moisture, light, temperature etc. If you don’t know it about your sample, ask us ! The tested specimen (ruptured) can be recovered.

The report includes a table with raw data, a pdf-file with experimental curve (e.g. stress-strain diagram) and requested calculated values of ultimate stress, elongation at break, Young’s modulus, stress at break etc. The report can include any visual observations about material’s behavior during testing.

Polymeric materials consist of long-chain macromolecules that are randomly entangled with each other. This amorphous matrix can exist in a brittle, glassy state, e.g., polyacrylic glass lenses, or can transition to a highly elastic state when heated above a certain temperature, e.g., PE films. Some polymers can form dense ordered structures, crystallites, that are typically solid and non-elastic, e.g. PP sutures. A special class of materials has a network of covalent bonds interlinking its molecules, called cross-links, e.g., rubber. When a polymer is macroscopically deformed, first its amorphous matrix undergoes reversible viscoelastic deformation. When the stresses reach a certain threshold, the crystallites, if present, begin to deform by shear and rotation, resulting in elastoplastic deformation until they collapse into highly oriented fibril structures. Eventually, the stresses can reach such high values that the network begins to disintegrate or even covalent cross-links in the material can be mechanically destroyed. The different composition and molecular structure of polymers, as well as possible additives such as plasticizers or fillers, have a strong effect on the behavior of materials under mechanical stress and lead to different deformation states and values for the mechanical properties.
The tensile machine applies a force to the specimen to maintain a uniform strain/deformation that is constantly adjusted according to the mechanical behavior of the material due to changes in the material at the molecular level. This force is recorded for each specific time interval and strain, allowing the calculation of the mechanical parameters of the material.