How to accurately understand the physical properties of customer samples

TPE has many physical parameters. Hardness is a very important physical parameter for TPE (thermoplastic elastomer) materials. When a salesperson receives a customer sample or a new product trial, it is very important to timely and accurately understand the hardness of the customer's sample TPE material. This is of great significance for accurately recommending grades in engineering.

Under normal circumstances, the hardness value provided by the customer can be used as a reference for material selection, but it is best to let the customer provide a sample or sample material so that the engineer can accurately test the hardness of the material. Sometimes the customer may have a newly made product and may not necessarily grasp the hardness accurately. When testing hardness, experienced engineers generally measure positions where the sample is thicker and the surface is relatively flat, so the measurement results are more accurate. If the sample is thin or uneven, accurate hardness measurement is not possible. It is best if the user sends sample material; make a flat test piece about 3mm thick, then perform the measurement for more accurate results. If the customer does not have a sample and can only provide a hardness value, it is necessary to confirm the hardness unit. Shore hardness A and D have the same degree number, but the hardness difference is large.

Generally, TPE materials with hardness of 10~95A are usually measured with a Shore A durometer; for hardness above 95A, the Shore A durometer becomes insufficiently sensitive, so a Shore D durometer is generally used; for hardness below 10A, a Shore C (OO) durometer is used. The tip of the Shore D durometer indenter is sharp and needle-shaped, the Shore A durometer indenter tip is relatively blunt, and the Shore C durometer indenter tip is spherical-crown arc-shaped. When testing, attention should be paid to the hardness reading time. When testing material hardness, try to use delayed reading. Generally, thermoplastic elastomer TPE undergoes stress relaxation (yield) and creep under force. When reading the value, it is usually read 5~10 seconds after the material is forced (the Shore durometer indenter presses into the material). The reading time is slightly longer for softer TPE.