Testing the Tensile Strength of Plastics Using ASTM D 638 Test Standard

Tensile test is performed to measure the maximum force that created elongation in the samples to a great extent until the sample breaks. The test procedure helps to measure the actual strength of the plastic and composite product and provides a stress-strain diagram of materials for evaluating the tensile modulus property of the product. The final test data that comes out by following the test procedure as suggested by standardization authorities ASTM, ISO, helps to specify the quality of the materials and design of the product that ascertain whether the product can withstand various application forces or not.

Calculations Possible with Tensile Test 

The tensile test performed on the plastics, and other composites help to determine the following properties of material:

  • Tensile strength at the final breaking point,
  • Tensile stress-strain curve
  • Tensile modulus or Young modulus
  • Elongation force and percentage of elongation at yield point.
  • Elongation force and percentage of elongation at break point.

ASTM D-638 is the best standard test method introduced by the standardization authorities to test the tensile strength of plastics. The test method helps to measure the tensile strength, elongation force and Tensile/Young modulus of all type of plastic materials.

 

Tensile Test Procedure as per ASTM D-638

According to the standard test method ASTMD – 638, the sample is placed in the provided grips which are designed as per the type of the sample to clamp the sample easily and firmly at a specified rate of grip separation. After clamping the sample, the device is set in position to move until the sample fails or ruptures. The speed of the test is determined according to the specifications of the sample. Moreover, in some cases, extensometer is also used for determining actual elongation and tensile modulus.

Plastic Tensile Testing Machine by Presto

Presto Stantest offers a wide variety of tensile testing machine that is used to fulfill the requirements of different test applications. These testing instruments are used to create a different amount of force and with different speed as per the test requirement.

Technical Specifications of Presto’s Tensile Testing Machine

Presto’s Tensile Testing machine is a C.R. E. type model which is designed using premium quality of mild steel. The instrument works with a crosshead speed of 50 mm to 500mm per minute and is duly fitted with a Servo Motor. This helps the machine to move with variable speed as per the requirement of the test. The instrument is fitted with an overload travel safety device which ensures the reliability and accuracy of the test and test results.