Client’s request
The client needs to evaluate the tension mechanical properties of a urethane-based material (TPU) that will be used at a temperature of about -40°C. It is therefore essential for the client to have the possibility of studying the mechanical behavior of the material (ISO 527) at a temperature other than the ambient one of 23°C. By evaluating the mechanical strength at -40°C, they will be able to establish whether the material they plans to use is suitable or not for the application.
The solution proposed by Plastanalysis
The Plastanalysis laboratory is equipped with a dynamometer with a climatic chamber and can therefore perform the test at temperatures other than ambient (classic working range -40°C – +220°C). The equipment for carrying out the tests is composed of:
- Dynamometer with double load cell 25 kN and 1 kN;
- Clamps for tensile, bending tests, plates for compression tests;
- Climatic chamber from -70°C to +280°C;
- Video extensometer;
- Innovative software for processing customized reports (examples of analysis are shown below).
The characterization of polymeric materials represents one of the fundamental aspects in the field of materials engineering and industrial research. This type of analysis, especially with regard to the influence of temperature and deformation speed, allows one to understand how these parameters affect the mechanical behavior of the polymer, providing valuable information to optimize production processes and ensure reliable performance in operation. In the design of plastic components, it is essential to know and predict the behavior of the material when subjected to different stress conditions. Temperature and deformation speed are two quantities that, in a synergistic way, modify key parameters such as strength, ductility, elastic modulus, energy dissipation capacity and breaking modes. The need to fully understand these effects is crucial especially in the automotive, electronic and electrical sectors, as well as in various industrial contexts where polymeric materials are exposed to thermal ranges and stress rates significantly varied.
Influence of temperature on mechanical properties
Temperature is one of the parameters with the greatest impact on the mechanical response of plastic materials. In general, as the temperature increases, a plastic material tends to decrease its stiffness (elastic modulus) and its tensile strength, becoming more ductile. On the contrary, at low temperatures, the mechanical behavior becomes more brittle, with a higher elastic modulus.
Tensile and bending tests at various temperatures
Standard specimens are prepared (usually dog-bone-shaped, according to standards such as ISO 527 for tensile tests or 80x10x4 mm specimens according to ISO 178 for bending tests) and tensile or bending tests are carried out at different temperatures. These tests make it possible to evaluate how the elastic modulus, the breaking load and the elongation at break vary as a function of temperature. From a practical point of view, the correct characterization of these effects enables the design of safer pieces and helps avoid unforeseen failure phenomena. At the same time, it constitutes the basis for the development of new polymeric alloys and composites capable of offering better performance. Moreover, understanding of these phenomena is relevant in industries where the rapid deformation of the product and the variation of temperature are frequent, such as in injection molding or hot molding of semi-finished products.
Analysis results
The customer is provided with a detailed table (which is shown as an example) in which the data obtained from the tests mentioned above are reported. The customer then can evaluate the suitability for the application of the material (TPU) based on the results obtained.
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