Information on the most widely used ASTM standards within the materials testing industry
ISO 527-1 Plastics — Determination of tensile properties Part 1: General principles
ISO 527-2 Plastics -- tensile properties -- Part 2: moulding and extrusion
ISO 527-1 covers the test procedures for determining tensile properties of plastics and plastic composites. Tensile properties of plastics that are determined through the practices of ISO 527-1 include tensile strength, tensile modulus and other properties related to stress strain characteristics of plastic materials. According to ISO 527-1, tensile testing of plastics is executed by pulling a test specimen along a major longitudinal axis at a constant rate of extension until failure of the plastic specimen occurs or until a predetermined stress or strain value. ISO 527-1 requires stress and strain measurements to be recorded through the plastic tensile test.
Plastic tensile test specimens are to be used to testing in accordance to ISO 527-1. Plastic components are not tested with the practices of ISO 527-1. The purpose of ISO 527-1 is to determine tensile properties of plastics, and not to determine stress behavior of plastic components.
ISO 527-2 specifies the test conditions for determining the tensile properties of moulding and extrusion plastics, based upon the general principles given in ISO 527-1. The methods described in ISO 527-2 are selectively suitable for use with the following range of materials: rigid and semi-rigid thermoplastics moulding, extrusion and cast materials, including compounds filled and reinforced by, thickness ≥1 mm. (Less 1mm use ISO 527-3). for example, short fibres, small rods, plates or granules but excluding textile fibres (see ISO 527-4 and ISO 527-5).
ISO 527-1/-ISO 527-2 and ASTM D638 both specify tensile test methods. These standards are technically equivalent but do not provide completely comparable results, as specimen shapes, test speeds and method of result determination differ in some respects.
The test methods of can be used to test a wide variety of plastic materials, including:
Thermoplastics for molding and extruding.
Thermosetting molding materials
Fiber reinforced thermoset and thermoplastics composites
Thermotropic liquid crystal polymers.
Scope:
Tensile tests measure the force required to break a plastic sample specimen and the extent to which the specimen stretches or elongates to that breaking point.
Test Procedure:
Specimens are placed in the grips of the universal tester at a specified grip separation and pulled until failure. For ISO 527 the test speed is typically 5 or 50mm/min for measuring strength and elongation and 1mm/min for measuring modulus. An extensometer is used to determine elongation and tensile modulus.
Specimen size: The most common specimen for ISO-527 is the ISO-3167 Type 1A multipurpose specimen.
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The following calculations can be made from tensile test results:
*Tensile strength (at yield and at break)
*Tensile modulus
*Strain
*Elongation and percent elongation at yield
*Elongation and percent elongation at break.
Them cover a range of plastics including thermosets, thermoplastics, and fiber-reinforced plastics. Test specimens may be rigid, semi-rigid, molded or extruded plastics, and are commonly in the shape of a dumbbell or dog bone.
The mechanical properties of plastics vary depending on the type of plastic, as well as the additives that may be incorporated into the formulation. Properties, such as strength, ductility and toughness, are influenced by different types of additives. To determine the appropriate testing equipment, it is important to understand how material behavior changes as a result of the various additives.
Key Differences Between ISO 527-1 and ISO 527-2
| Aspect | ISO 527-1 | ISO 527-2 |
|---|---|---|
| Focus | General principles and framework | Specific test conditions for rigid plastics (≥1 mm). |
| Specimen | Defines general requirements | Detailed specimen types, dimensions, and tolerances. |
| Speed | General guidelines | Specific speeds for different material types. |
| Application | All plastics | Rigid/semi-rigid molding and extrusion plastics. |
| Mandatory | Yes (for all ISO 527 testing) | Yes (for rigid plastic testing). |
Key Applications (Industry Fields)
Automotive: Interior/exterior components, under-the-hood parts
Packaging: Rigid containers, caps, closures
Construction: Pipes, profiles, window frames
Electronics: Housings, connectors, insulators
Medical: Device components, surgical instruments
Consumer Goods: Toys, appliances, furniture parts
Related products and device
Related Standard
ISO 527-4 and ISO 527-5 are two key standards within the ISO 527 series for determining the tensile properties of fibre-reinforced plastic composites.
ISO 527-4 covers the general principles and tests for isotropic and orthotropic materials. ISO 527-5 provides specific procedures for testing unidirectional fiber-reinforced composites.
These standards are critically important because they provide a unified, reliable method to measure fundamental mechanical properties (like tensile strength, modulus, and strain) which are essential for material selection, quality control, structural design, and R&D in aerospace, automotive, wind energy, and sports equipment industries.
ISO 527-3 Plastics - TENSILE PROPERTIES - PART 3: FOR FILMS AND SHEETS
ISO 527-3 is a common international standard that is used to determine the tensile properties of plastic film or sheeting - a plastic test specimen with a thickness less than 1 mm. The tensile properties include tensile strength, yield strength, yield strain, strain at break, and in some cases Young's Modulus. Due to the flexible, delicate nature of these plastic specimens, both gripping and strain measurement can be a challenge.
ISO 527-3 Tensile Test of Plastic Thin Film Sheet
It covers the specimen preparation requirements of thin plastic sheets and films. Thin plastic specimens created with the practices of ISO 527-3 are tensile tested with the practices of ISO 527-1. Thin plastic specimens created in accordance with ISO 527-3 are cut, or punched from a sheet of thin plastic. ISO 527-3 specifies that thin plastic film of sheet specimens must be free from cracks or scratches that will affect the tensile test. ISO 527-3 allows for four specimen geometries that can be used for tensile testing. There are three acceptable dogbone shaped specimens that are acceptable. Specimen created following ISO 527-3 can be used to determine the tensile properties of thin plastic sheets and films including the tensile modulus of elasticity and the tensile energy to break (TEB).
ASTM D638 : Standard Test Method for Tensile Properties of Plastics
ASTM D638 specifies methods for testing the tensile strength of plastics and other resin materials and for calculating their mechanical properties, and outlines accuracy requirements for the test frames and accessories used. This test method uses dumbbell-shaped specimens with either a 25 mm or 50 mm gauge length.
ASTM D882: Standard Test Method for Tensile Properties of Thin Plastic Sheeting
ASTM D882 test methods is used to measure tensile properties including ultimate tensile strength, yield strength, elongation, tensile energy to break and tensile modulus of elasticity of thin plastic sheeting and films. The samples are cut in strips that minimally have to be eight times longer than wide. No dumbbell shape is cut for materials of that thickness. Cut samples need to be free of nicks and other cutting defects since they will have an important impact on the test results variation. The samples are tested in specific conditions of pre-treatment, sample orientation, temperature, humidity, and rate of pulling. ASTM D882 can be used for testing materials thinner than 1mm in thickness.
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