The procedure for measuring the physical properties of plastics using a tensile tester is summarized below.
Tensile Testing Procedure
Specimen Preparation
Prepare test specimens according to standards. The shape and size of the specimen should follow standards such as ASTM D638 and ISO 527.
Ensure that the specimen is free from scratches or defects, as these will affect the results of the tensile test. In the image below, a punching jig is used to punch out the test specimen.
Mounting the test specimen
Mount the test specimen in the chuck of the tensile tester. Take care to ensure that the specimen is correctly centered.
Secure the specimen firmly so that it will not loosen.
Running the Test
The test is started so that the tensile tester applies a tensile force to the specimen at a constant rate.
During the test, the deformation of the specimen is measured using a displacement transducer or strain gage.
The tester continues to apply tensile force until the specimen fails.
Data Recording
Stress (force) and strain (deformation) data are recorded using the tester's data acquisition system.
Stress-strain curves are generated, and based on these curves, physical properties such as tensile strength, yield strength, elongation modulus, and elastic modulus are calculated.
Analysis of test results
The data obtained is analyzed and evaluated according to standards and criteria.
The test results are compiled into a report, which includes test conditions, specimen properties, and graphs and numerical values of the test results.
Main physical properties of tensile tests
Tensile Strength: Maximum stress at which the specimen breaks.
Yield strength: Stress at which the material begins to deform permanently.
Elongation: The rate of deformation of a specimen until it breaks (elongation at break).
Modulus of Elasticity: The ratio of stress to strain over a linear range (Young's modulus).
Tensile testing is a fundamental test method for evaluating the mechanical properties of plastic materials and provides important information for material selection and quality control.
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