ISO/TC 61/SC 2/WG 3 - Impact and high speed properties

1.1 This document specifies a method for determining Charpy impact properties of plastics from force-deflection diagrams. Different types of rod-shaped test specimens and test configurations, as well as test parameters depending on the type of material, the type of test specimen and the type of notch, are defined in ISO 179-1. Dynamic effects such as load-cell/striker resonance, test specimen resonance and initial-contact/inertia peaks are described in this document (see Figure 1, Curve b, and Annex A). 1.2 ISO 179-1 is suitable for characterizing the impact behaviour by the impact strength only and for using apparatus whose potential energy is matched approximately to the particular energy to break to be measured (see ISO 13802:2015, Annex E). This document is used to record a force-deflection or force-time diagram for detailed characterization of the impact behaviour, and for developing automatic apparatus, i.e. avoiding the need to match energy. The method described in this document is also suitable for: — acquiring more and different materials characteristics under impact conditions; — supervising the Charpy test procedure, as this instrumentation allows detection of typical operational mistakes, such as the specimen not being in close contact with the supports; — automatically detecting the type of break; — pendulum type instruments to avoid frequent changes of pendulum hammers; — measuring fracture mechanical properties described in other ISO standards. 1.3 For the range of materials which can be tested by this method, see ISO 179-1:2010, Clause 1. 1.4 For the general comparability of test results, see ISO 179-1:2010, Clause 1. 1.5 Information on the typical behaviour of materials can be obtained by testing at different temperatures, by varying the notch radius and/or specimen thickness and by testing specimens prepared under different conditions. It is not the purpose of this document to give an interpretation of the mechanism occurring at every point on the force-deflection diagram. These interpretations are a task for on-going scientific research. 1.6 The test results obtained with this method are comparable only if the conditions of test specimen preparation, as well as the test conditions, are the same. The impact behaviour of finished products cannot, therefore, be predicted directly from this test.

1.1 This document specifies a method for determining the Izod impact strength of plastics under defined conditions. A number of different types of specimen and test configurations are defined. Different test parameters are specified according to the type of material, the type of test specimen and the type of notch. 1.2 The method is used to investigate the behaviour of specified types of specimen under the impact conditions defined and for estimating the brittleness or toughness of specimens within the limitations inherent in the test conditions. 1.3 The method is suitable for use with the following range of materials: — rigid thermoplastic moulding and extrusion materials, including filled and reinforced compounds in addition to unfilled types; rigid thermoplastics sheets; — rigid thermosetting moulding materials, including filled and reinforced compounds; rigid thermosetting sheets, including laminates; — fibre-reinforced thermosetting and thermoplastic composites incorporating unidirectional or non-unidirectional reinforcements such as mat, woven fabrics, woven rovings, chopped strands, combination and hybrid reinforcements, rovings and milled fibres and sheet made from pre-impregnated materials (prepregs); — thermotropic liquid-crystal polymers. 1.4 The method is not normally suitable for use with rigid cellular materials and sandwich structures containing cellular material. Notched specimens are also not normally used for long-fibre-reinforced composites or thermotropic liquid-crystal polymers. 1.5 The method is suited to the use of specimens which can be either moulded to the chosen dimensions, machined from the central portion of a standard multipurpose test specimen (see ISO 20753) or machined from finished or semi-finished products such as mouldings, laminates and extruded or cast sheet. 1.6 The method specifies preferred dimensions for the test specimen. Tests which are carried out on specimens of different dimensions or with different notches, or specimens which are prepared under different conditions, may produce results which are not comparable. Other factors, such as the energy capacity of the apparatus, its impact velocity and the conditioning of the specimens can also influence the results. Consequently, when comparative data are required, these factors are to be carefully controlled and recorded. 1.7 The method is not intended to be used as a source of data for design calculations. Information on the typical behaviour of a material can be obtained, however, by testing at different temperatures, by varying the notch radius and/or the thickness and by testing specimens prepared under different conditions.

ISO 13802:2015 specifies frequency and methods for the verification of pendulum impact-testing machines used for the Charpy impact test, Izod impact test, and tensile impact test described in ISO 179‑1, ISO 180, and ISO 8256, respectively. Verification of instrumented impact machines is covered insofar as the geometrical and physical properties of instrumented machines are identical to non instrumented machines. The force/work verification of instrumented machines is not covered in this International Standard.

ISO 179-1:2010 specifies a method for determining the Charpy impact strength of plastics under defined conditions. A number of different types of specimen and test configurations are defined. Different test parameters are specified according to the type of material, the type of test specimen and the type of notch. The method can be used to investigate the behaviour of specified types of specimen under the impact conditions defined and for estimating the brittleness or toughness of specimens within the limitations inherent in the test conditions. It can also be used for the determination of comparative data from similar types of material. The method has a greater range of applicability than that given in ISO 180 (Izod impact testing) and is more suitable for the testing of materials showing interlaminar shear fracture or of materials exhibiting surface effects due to environmental factors. The method is suitable for use with the following range of materials: rigid thermoplastic moulding and extrusion materials (including filled and reinforced compounds in addition to unfilled types) and rigid thermoplastics sheets; rigid thermosetting moulding materials (including filled and reinforced compounds) and rigid thermosetting sheets (including laminates); fibre-reinforced thermosetting and thermoplastic composites incorporating unidirectional or multi-directional reinforcements (such as mats, woven fabrics, woven rovings, chopped strands, combination and hybrid reinforcements, rovings and milled fibres) or incorporating sheets made from pre-impregnated materials (prepregs), including filled compounds; thermotropic liquid-crystal polymers.

ISO 8256:2004 specifies two methods (method A and method B) for the determination of the tensile-impact strength of plastics under defined conditions. The tests can be described as tensile tests at relatively high strain rates. These methods can be used for rigid materials (as defined in ISO 472), but are especially useful for materials too flexible or too thin to be tested with impact tests conforming to ISO 179 or ISO 180. These methods are used for investigating the behaviour of specified specimens under specified impact velocities, and for estimating the brittleness or the toughness of specimens within the limitations inherent in the test conditions. These methods are applicable both to specimens prepared from moulding materials and to specimens taken from finished or semi-finished products (for example mouldings, films, laminates, or extruded or cast sheets). Results obtained by testing moulded specimens of different dimensions may not necessarily be the same. Equally, specimens cut from moulded products may not give the same results as specimens of the same dimensions moulded directly from the material. Test results obtained from specimens prepared from moulding compounds cannot be applied directly to mouldings of any given shape, because values may depend on the design of the moulding and the moulding conditions. Results obtained by method A and method B may or may not be comparable. These methods are not suitable for use as a source of data for design calculations on components. Information on the typical behaviour of a material can be obtained, however, by testing different types of test specimen prepared under different conditions, and by testing at different temperatures. The two different methods are suitable for production control as well as for quality control.

This International Standard specifies methods for the determination of puncture-impact properties of rigid plastics in the form of flat test specimens, such as discs or square pieces, under defined conditions. Specimens may be moulded directly, cut from sheets or taken from finished products. Different types of test specimens and test conditions are defined. These falling-dart methods are used to investigate the behaviour of plastic sheeting or mouldings under the impact of a striker applied perpendicular to the plane of the specimen. This part of ISO 6603 can be used if it is sufficient to characterize the impact behaviour of plastics by a threshold value of impact-failure energy based on many test specimens. ISO 6603-2 is used if a force-deflection or force-time diagram, recorded at nominally constant striker velocity, is necessary for detailed characterization of the impact behaviour. These test methods are applicable to specimens with a thickness between 1 mm and 4 mm. NOTE For thicknesses less than 1 mm, ISO 7765 should preferably be used. Thicknesses greater than 4 mm may be tested if the equipment is suitable, but the test falls outside the scope of ISO 6603-1 and ISO 6603-2. These methods are suitable for use with the following types of material: _ rigid thermoplastic moulding and extrusion materials, including filled, unfilled and reinforced compounds and sheets; _ rigid thermosetting moulding and extrusion materials, including filled and reinforced compounds, sheets and laminates; _ fibre-reinforced thermoset and thermoplastic composites incorporating unidirectional or non-unidirectional reinforcements such as mats, woven fabrics, woven rovings, chopped strands, combination and hybrid reinforcements, rovings, milled fibres and sheets made from pre-impregnated materials (prepregs). These methods are also applicable to specimens which are either moulded or machined from finished products, laminates and extruded or cast sheet. The test results are comparable only if the conditions of preparation of the specimens, their dimensions and surfaces as well as the test conditions are the same. In particular, results determined on specimens of different thickness cannot be compared with one another (see annex E of ISO 6603-2:—). Comprehensive evaluation of the reaction to impact stress requires that determinations be made as a function of impact velocity and temperature for different material variables, such as crystallinity and moisture content. The impact behaviour of finished products cannot be predicted directly from this test, but specimens may be taken from finished products (see above) for test by these methods. Test data developed by these methods should not be used for design calculations. However, information on the typical behaviour of the material can be obtained by testing at different temperatures and impact velocities (see annex D of ISO 6603-2:—), by varying the thickness (see annex E of ISO 6603-2:—) and by testing specimens prepared under different conditions. Two statistical methods of test are described in this part of ISO 6603: _ Method A: staircase method (individual) (preferred) In this method, a uniform energy increment is employed during testing. The energy is decreased or increased by the uniform increment after testing each specimen, depending upon the observed result (pass or fail) for the preceding test. _ Method B: group method (optional) In this method, successive groups of at least ten test specimens are tested. The impact failure energy is calculated by statistics.

This International Standard specifies a method for the determination of the temperature at which plastics that are not rigid at normal ambient temperature exhibit brittle failure under specified impact conditions. A supplementary technique using notched specimens develops brittleness values at a much higher temperature than are observed for unnotched specimens of the same plastic material. The method utilizes a statistical technique to quantify the brittleness failure temperature. Provisions are made for the testing of sufficient specimens to permit the calculation of the brittleness temperature on a statistical basis. Statistical techniques have been developed to quantify the brittleness temperature as is defined in 3.1. The method establishes the temperature at which there is a 50 % chance of failure in either unnotched or notched specimens. This method has been found useful for specification purposes, although it does not necessarily measure the lowest temperature at which the material may be used. In the measurement of the brittleness temperature, the precision of the measurement should preferably be _ 5 °C at the worst when establishing values used in material specifications.

Specifies two methods for the determination of the energy required to rupture test specimens of plastics under a specified tensile-impact velocity. The tests can be described as tensile tests at comparatively high rates of straining. These methods are applicable to specimens prepared from moulding materials or to specimens taken from finished or semi-finished products. These methods are not suitable for use as a source of data for design calculations on components.