Plastic Tensile Strength Test

How to perform a tensile test on plastics according to iso 527 2.

Plastic tensile strength test.

The test method can be used for testing materials up to 14mm 0 55 in and the material should be in the shape of a dumbbell or dog bone. A wide variety of grips are available for tensile testing of plastics. Tensile testing is a destructive test process that provides information about the tensile strength yield strength and ductility of the metallic material. Separate tensile test methods are commonly applied to polymer films astm d882 or iso 1184 and elastomers astm d412 or iso 37.

Astm d638 is one of the most common plastic strength specifications and covers the tensile properties of unreinforced and reinforced plastics. A tensile test is typically governed via standards and the two most common in the plastics industry are astm d638 and iso 527. The tensile testing machine pulls the sample from both ends and measures the force required to pull the specimen apart and how much the sample stretches before breaking. The figure below from quadrant engineering plastic products shows the test geometry.

This includes astm d638 technically equivalent to iso 527 1 is a testing standard which ascertains the tensile properties of a plastic material. In addition the wintest software includes all applicable calculations like yield stress strain e modulus uts etc. With the use of plastics being at an all time high it is critical that manufacturers be able to properly gauge the mechanical strength of their materials. For this test plastic samples are either machined from stock shapes or injection molded.

A universal testing machine tensile testing machine is needed to perform this test. These include several types of self tightening manual hydraulic and pneumatic versions that are necessary for positive gripping. The most common way to measure the yield strength of plastics is with a tensile test. Astm d638 is the most common testing standard for determining the tensile properties of reinforced and non reinforced plastics.

The test measures the force as a function of the strain being applied to the plastic sample. The test is conducted at tensile rates ranging from 1 to 500 mm min until the specimen fails yields or breaks.