ISO 527-2 Tensile Properties of Molded & Extrusion Plastics

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ISO 527-2 Tensile Properties of Molded & Extrusion Plastics

The ISO 527-2 standard provides a means of measuring the tensile properties of molded and extrusion plastics.

What Is ISO 527-2?

ISO 527-2 is the international standard for testing rigid and semi rigid thermoplastic molded, extruded, and cast materials including plastics that have been filled and reinforced by short rods, plates, fibers and granules. Thermoset materials are also included. Note that polymer matrix composites are tested in accordance with ISO 527-4 and ISO 527-5.

Why Perform ISO 527-2 Tests?

Testing per ISO 527-2 is performed for several reasons including engineering design, internal quality assurance, and to compare one material versus another. The test results include a wide range of tensile properties including tensile strength, tensile modulus, elongation, and Poisson's ratio.

Test Machines for Unreinforced & Reinforced Plastics

Our universal test machines serve multiple plastic testing applications and are capable of performing all quasi static tension/compression tests, such as tensile, peel, adhesion, and flexural testing. The machine force capacity should be chosen by taking into account the highest force needed over the lifetime of the equipment. Our machines feature a uniform constant rate of extension (CRE), or constant velocity control mode, with a speed range between 1 and 500 mm per minute (0.04 to 20 in/min). Force measurement complies with ISO 7500-1. The test equipment meets ISO 5893 and complies with ISO 527-1. The majority of rigid plastics tests can be performed at loads under 25 kN (5500 lbs).

What Test Fixtures Are Recommended for Rigid Unreinforced & Reinforced Plastics?

For gripping plastic and rubber dumbbells, parallel strips and similar tensile test samples of flexible rubber or plastic materials, the grips should close automatically as the tension increases (e.g. wedge, or pneumatic grips). The grips should also exert a uniform pressure across the whole width of the test sample. For rigid materials, mechanical screw action grips are also available. The test sample slippage in the grips is to be prevented as much as possible.

Pneumatic Vise Grips offer ease of sample loading, consistent clamping force, self alignment, and interchangeable jaws with smooth, serrated, and corrugated (wave) surfaces. For this application, see G83 Pneumatic Vise Grips.

Wedge Action Grips tend to provide high force capacity and are available in mechanical or manual, pneumatic and hydraulic action. When under tension, their two jaws are drawn tighter together in a self tightening mode. For this application, see G622 Mechanical Wedge Grips, and G175 Family of Pneumatic Grips.

ISO 527-2 Specimens

ISO 527-2 sample thickness is 4 mm (0.157 in). Most test specimens are produced by injection molding where inconsistent mechanical strength occurs along the length of the specimen, due to differing distances away from the gate. The most common gauge length for the specimen is 75 mm (2.9 in), with 50 mm (1.9 in) optional. Type 1B specimens feature a gauge length of 50 mm (1.9 in) due to the larger radius resulting in a shorter parallel area.