Choose the Right Sized Specimen for Tensile Testing Machine

Choose the Right Sized Specimen for Tensile Testing Machine

A successful tensile testing of vulcanized rubber and thermoplastic elastomers used in footwear soles, tires, sports equipment etc. is conducted by following the ASTM D412 testing standard. This testing method is appropriate for rubber material as they are comprised of complicated components which deliver both elasticity during stretching and recoil upon release. Also, it is important to use a prime level tensile testing machine to conduct a standardized test.

Applications of Rubber Compound

Rubber compounds which are used in applications are formulas that have been optimized with the precise amount of several components. A very simple and a common example of elastomer material is toys, which are made up of plasticized PVC. In terms of complex structures, there are many elastomers utilized in aerospace applications which deliver high-performance specifications even in extreme temperature conditions.

Selecting the right size for testing specimen

Test method ‘A’ of ASTM D412 is a renowned testing standard. It is popularly preferred for testing the tensile strength of vulcanized thermal set rubber materials and thermoplastic elastomers. As per this method, the testing specimen should comprise of a dumbbell shape. But lab technicians often get confused while deciding the specimen geometry. It happens because the specimen chart presented in the standard states multiple geometrical structures without clearing which one to use for which material. Anisotropy or grain directional features becomes an issue in selecting these kinds of materials. Therefore the testing sample must be selected in such a way that one can orient and cut the specimens lengthwise in the direction of the grain.

Tensile Testing Procedure

  1. Cut the rubber material into a dumbbell-shaped
  2. Mount the testing sample in between the tensile grips.
  3. Initiate the test by separating the tensile grips at a fixed decided.
  4. End the test after the sample break or ruptures.

Properties evaluated from the above test are stress value at extension, tensile yield stress, tensile yield strain, tensile strength at rupture stage and elongation amount at rupture.

At Presto testing instrument, we understand the need for elastomer tensile testing. We offer a range of testing equipment required for ASTM D412 tensile testing such as the tensile testing machine and Dumbbell cutting die. These machines are widely used in industries like rubber, plastic, textile, packaging and many more.