CEN/TC 249 - Plastics

1.1        This document specifies the test conditions for determining the tensile properties of moulding and extrusion plastics, based upon the general principles given in ISO 527-1.
1.2        The methods are selectively suitable for use with the following range of materials in the preferred thickness, or, in case of specimen machined from moulded parts in the thickness as moulded:
—          rigid and semi-rigid thermoplastics moulding, extrusion and cast materials, including compounds filled and reinforced by, for example, short fibres, small rods, plates or granules but excluding textile fibres (see ISO 527-4 and ISO 527-5).
NOTE   See ISO 527-1:2019, Clause 3 for the definition of "rigid" and "semi-rigid".
—          rigid and semi-rigid thermosetting moulding and cast materials, including filled and reinforced compounds but excluding textile fibres as reinforcement (see ISO 527-4 and ISO 527-5);
—          thermotropic liquid crystal polymers.
The methods are not normally suitable for use with rigid cellular materials or sandwich structures containing cellular material. For rigid cellular materials, see ISO 1926.
The methods are not suitable for flexible films and sheets, of thickness smaller than 1 mm, see ISO 527-3.
1.3        The methods are applied using specimens which can be either moulded to the chosen dimensions or machined, cut or punched from injection‑ or compression‑moulded plates. The multipurpose test specimen is preferred (see ISO 20753).

This document specifies the main characteristics and associated test methods for assessing of polyethylene (PE) recyclates intended for use in the production of semi-finished or finished products.
It is intended to support parties involved in the use of PE recyclates to agree on specifications for specific and generic applications.
This document does not cover the characterization of plastics wastes, which is covered by the EN 15347 series, neither traceability topics which are covered by EN 15343.

This document specifies methods for the determination of oxidation induction time (isothermal OIT) and oxidation induction temperature (dynamic OIT) of polymeric materials by means of differential scanning calorimetry (DSC). It is applicable to polyolefin resins that are in a fully stabilized or compounded form, either as raw materials or finished products. It can be applicable to other plastics.

This document specifies the main characteristics and associated test methods for assessing of polypropylene (PP) recyclates intended for use in the production of semi-finished/finished products.
It is intended to support parties involved in the use of PP recyclates to agree on specifications for specific and generic applications.
This document does not cover the characterization of plastic wastes, which is covered by the EN 15347 series, neither traceability topics which are covered by EN 15343.

This document specifies the main characteristics and associated test methods for assessing of polystyrene (PS) recyclates intended for use in the production of semi-finished/finished products.
It is intended to support parties involved in the use of PS recyclates to agree on specifications for specific and generic applications.
This document does not cover the characterization of plastics wastes, which is covered by the EN 15347 series, neither traceability topics which are covered by EN 15343.

This document specifies a method for the determination of the temperatures and enthalpies of melting and crystallization of crystalline or partially crystalline plastics using conventional DSC as specified in ISO 11357-1.
This document is not applicable to fast DSC as specified in ISO 23976.

This document specifies the main characteristics and associated test methods for assessing of acrylonitrile-butadiene-styrene (ABS) recyclates intended for use in the production of semi-finished/finished products.
It is intended to support parties involved in the use of ABS recyclates (rABS) to agree on specifications for specific and generic applications.
This document does not cover the characterization of plastic wastes, which is covered by the EN 15347 series, neither traceability topics which are covered by EN 15343.

This document applies to unplasticized poly(vinyl chloride) (PVC-U) profiles that are intended to be used for the fabrication of windows and doors in accordance with the EN 14351 series or EN 16034, shutters according to EN 13659 and other construction profiles in accordance with the EN 13245 series. Furthermore, this document is also applicable for profiles used in other PVC-U products, which can include recyclates. This document gives references and specifies general and product-specific design for recycling principles.
NOTE 1   In this document, the term “PVC-U profiles” is used to refer to construction profiles made from PVC-U, PVC-UE, and PVC-U-based natural fibre composites (NFC).
NOTE 2   For editorial reasons in this document the term window is used for window/door.
Criteria for the use of materials, process conditions, and recyclability are defined, which are considered during the design process.
This document defines principles to
-   obtain the highest possible share of recyclability of the PVC-U part in the profile, and
-   increase the share of PVC-U recyclate in the profile,
while complying with requirements for the final product, where existent and defined elsewhere. This document establishes flowcharts which help to assess, (i) how recyclability is evaluated and (ii) whether inclusion of rPVC-U is possible.
The following components of the final PVC-U construction product are considered in this document:
-   profiles;
-   reinforcements;
-   gaskets;
-   insulations;
-   coverings.
This document specifies only the technical connection of the profile to other components (such as glazing or hardware) and their impact on the recyclability of the PVC-U profiles. The recyclability of the other components (e.g. glazing, aluminium cover, hardware) is excluded from this document.
NOTE 3   Examples for profiles included in this document and their intended use can be found in Figure 1.
Figure 1 - Examples for profiles included in this document and their intended use (frame and sash profile with reinforcements, window, door, cladding and shutter box with shutter)

This document specifies the quality grades for sorted Polyethylene (PE) wastes as well as specific test methods laying out those properties for which the supplying party of the waste makes information available to the receiving party. Polyethylene waste quality grades are based on pre-determined sets of characteristics, taking into account sectorial and market specificities and related information needs and tests methods. The document provides for a division of information between “Required Data”, where a statement is required, and additional “Optional Data” as agreed between the supplying and receiving party.
This document does not apply to the general characterization addressed in EN 15347-1.

This document specifies a method for the determination of reaction temperatures and times, enthalpies of reaction, and degrees of conversion using conventional differential scanning calorimetry (DSC) as specified in ISO 11357-1.
The method applies to monomers, prepolymers, and polymers in the solid or liquid state. The material can contain fillers and/or initiators in the solid or liquid state.
This document is not applicable to fast DSC as specified in ISO 23976.[1]

This document specifies the quality grades for sorted polypropylene (PP) wastes as well as specific test methods laying out those properties for which the supplying party of the waste makes information available to the receiving party. Polypropylene waste quality grades are based on pre-determined sets of characteristics, taking into account sectorial and market specificities and related information needs and tests methods. The document provides for a division of information between “Required Data”, where a statement is required, and additional “Optional Data” as agreed between the supplying and receiving party.
This document does not apply to the general characterization addressed in EN 15347-1.

This document specifies the quality grades for sorted poly(vinyl chloride) (PVC) wastes as well as specific test methods laying out those properties for which the supplying party of the waste makes information available to the receiving party. PVC waste quality grades are based on pre-determined sets of characteristics, taking into account sectorial and market specificities and related information needs and tests methods. The document provides for a division of information between “Required Data”, where a statement is required, and additional “Optional Data” as agreed between the supplying and receiving party.
This document does not apply to the general characterization addressed in EN 15347-1.

This document specifies the quality grades for sorted poly(ethylene terephtalate) (PET) wastes as well as specific test methods laying out those properties for which the supplying party of the waste makes information available to the receiving party. PET waste quality grades are based on pre-determined sets of characteristics, taking into account sectorial and market specificities and related information needs and tests methods. The document provides for a division of information between “Required Data”, where a statement is required, and additional “Optional Data” as agreed between the supplying and receiving party.
This document does not apply to the general characterization addressed in EN 15347-1.

This document specifies the quality grades for sorted polystyrene (PS) wastes as well as specific test methods laying out those properties for which the supplying party of the waste makes information available to the receiving party. PS waste quality grades are based on pre-determined sets of characteristics, taking into account sectorial and market specificities and related information needs and tests methods. The document provides for a division of information between “Required Data”, where a statement is required, and additional “Optional Data” as agreed between the supplying and receiving party.
This document does not apply to the general characterization addressed in EN 15347-1.

This document specifies a tensile bending method and a compression bending method for determining the failure stress of welded corners and welded T-joints made from unplasticized poly(vinyl chloride) (PVC-U) profiles.
It is applicable to PVC based profiles used for the fabrication of windows and doors.

This document specifies three methods for the determination of the ash of poly(vinyl chloride).
The general procedures given in ISO 3451-1 are followed. For ash, method A is used. For sulfated ash, methods B and C are used. All three methods are applicable to resins, compounds and finished products. Methods B and C are applicable when lead-containing compounds are present.

This document has been developed to ensure transparency regarding the input stream for
recycling and to assist all plastic industry stakeholders in the development of new and improved
standards for plastic recycling.
The aim of this report is to present the current state of the debate on how to distinguish waste
materials that are suitable for the production of plastic recyclates from those that cannot be used
for recycling

This document specifies a method for determining the effect of heat on unplasticized poly(vinyl chloride) (PVC-U) profiles, to be carried out in air at 150 °C.
It is also applicable to PVC-based profiles at specified temperatures/test conditions.

This document defines test procedures for the acquisition and presentation of comparable data for moulding materials. This document applies predominantly to unreinforced and reinforced thermoplastic and thermosetting materials that can be injection- or compression-moulded or prepared as sheets of specified thickness.

This document specifies the general conditions for the determination of the reduced viscosity, intrinsic viscosity and K‑value of organic polymers in dilute solution. It specifies the standard parameters that are applied to viscosity measurement.
This document is applicable to develop standards for measuring the viscosities in solution of individual types of polymer. It is also applicable to measure and report the viscosities of polymers in solution for which no separate standards exist.

This document specifies the methods of preparation of test specimens and the test methods for determining the properties of polypropylene (PP) moulding and extrusion materials. It gives requirements for handling test material and for conditioning both the test material before moulding and the specimens before testing.
This document specifies procedures and conditions for the preparation of test specimens, and procedures for measuring properties of the materials from which these specimens are made. Properties and test methods which are suitable and essential to characterize PP moulding and extrusion materials are listed.
The properties have been selected from the general test methods in ISO 10350-1. Other test methods in wide use for, or of particular significance to PP moulding and extrusion materials are also included in this document, as are the designatory properties specified in ISO 19069-1.

This document provides the requirements for the tests made on welded thermoplastics semi-finished products.
The selection of the appropriate test method(s) is made in accordance with the particular type and application of welded product.
The test results depend on the conditions of manufacture for the test specimen and on the test conditions. They can therefore only be related to the behaviour of the product or can only be used for designing a structure, if the test conditions can be related to the service conditions.

This document specifies the methods of preparation of test specimens and the test methods for determining the properties of polyethylene (PE) moulding and extrusion materials. It gives requirements for handling test material and for conditioning both the test material before moulding and the specimens before testing.
This document specifies the procedures and conditions for the preparation of test specimens and procedures for measuring properties of the materials from which these specimens are made. Properties and test methods that are suitable and essential to characterize PE moulding and extrusion materials are listed.
The properties in this document have been selected from the general test methods in ISO 10350-1. Other test methods in wide use for or of particular significance to PE moulding and extrusion materials are also included in this document, as are the designatory properties specified in ISO 17855-1. Properties of slow crack growth, etc. are specified in documents of polyethylene (PE) materials for piping systems.
The methods of preparation and conditioning, the specimen dimensions and the test procedures specified herein are used to obtain reproducible and comparable test results. Values determined will not necessarily be identical to those obtained using specimens of different dimensions or prepared using different procedures.

This document specifies the classifications, requirements and test methods for unplasticized poly(vinyl chloride) (PVC-U) profiles with thermo-laminated foils designed for external uses which are intended to be used for the fabrication of windows and doors.
NOTE 1   For editorial reasons, in this document, the term "window" is used for window/door.
NOTE 2   For the purpose of production control, test methods other than those specified in this document can be used.

This document specifies methods for exposing plastic specimens to fluorescent UV lamp radiation, heat and water in apparatus designed to simulate the weathering effects that occur when plastic materials are exposed in actual end-use environments to global solar radiation, or to window-glass filtered solar radiation.
Fluorescent UV lamp exposures for paints, varnishes and other coatings are described in ISO 16474-3.

This document provides general guidance and requirements relevant to the selection and operation of the methods of exposure described in detail in subsequent parts of the ISO 4892 series. It also specifies general performance requirements for devices used for exposing plastics to laboratory light sources. Information regarding performance requirements is for producers of artificial accelerated weathering or artificial accelerated irradiation devices.
This document also provides information on the interpretation of data from artificial accelerated weathering or artificial accelerated irradiation exposures. More specific information about methods for determining the change in the properties of plastics after exposure and reporting these results is not part of this document.

This document specifies a method for determining the flexural creep of plastics in the form of standard test specimens under specified conditions such as those of pre-treatment, temperature and humidity. It is only applicable to a simple freely supported beam loaded at mid-span (three-point-loading test).
 The method is suitable for use with rigid and semi-rigid non-reinforced, filled and fibre-reinforced plastics materials (see ISO 472 for definitions) test specimens moulded directly or machined from sheets or moulded articles.
NOTE            The method can be unsuitable for certain fibre-reinforced materials due to differences in fibre orientation
The method is intended to provide data for engineering-design, quality control, research and development purposes.
The method might not be applicable for determining the flexural creep of rigid cellular plastics (attention is drawn in this respect to ISO 1209-1 and ISO 1209-2).

This document specifies a small-scale laboratory screening procedure for comparing the relative burning behaviour of vertically oriented thin and relatively flexible plastics specimens exposed to a low-energy-level flame ignition source.
NOTE  These specimens cannot be tested using method B of IEC 60695-11-10:2013 since they distort or shrink away from the applied flame source without igniting.
This test method determines the afterflame and afterglow times of specimens.
The classification system described in Annex A is intended for quality control and the preselection of component materials for products. The classification established by this method of test is applicable only to the material used for the specimens.
NOTE  Test results are influenced by material components, e.g. pigments, fillers, concentrations of fire retardants.

This document provides a scheme for the characterization of sorted plastics wastes, laying out those properties for which the supplying party of the waste makes information available to the receiving party. This document provides for a division of information between "Required Data", where a statement is required, and additional "Optional Data" as agreed between the supplying and receiving party.
This document is the general part of a series on sorted plastics wastes. This document does not cover the description of quality grades per polymer(s) and stream as well as test methods specific to each plastic waste stream; these aspects are addressed in the other parts of EN 15347.

This document specifies the main characteristics and associated test methods for assessing of poly(vinyl chloride) (PVC) recyclates intended for use in the production of semi-finished/finished products.
This document is intended to support parties involved in the use of PVC recyclates to agree on specifications for specific and generic applications.
This document does not cover the characterization of plastics wastes, which is covered by the EN 153471(series), nor traceability topics which are covered by EN 15343.
This document is applicable without prejudice to any existing legislation.

This document specifies the main characteristics and associated test methods for assessing of poly(ethylene terephthalate) (PET) recyclates intended for use in the production of semi-finished/finished products.
It is intended to support parties involved in the use of PET recyclates to agree on specifications for specific and generic applications.
This document does not cover the characterization of plastics wastes, which is covered by the EN 15347 series, neither traceability topics which are covered by EN 15343.
This document is applicable without prejudice to any existing legislation.

This document specifies the dimensions, the method of sampling, the preparation of the test specimens and the conditions for performing the tensile test with waisted test specimens in order to determine the tensile energy welding factor.
A tensile test with waisted specimens can be used in conjunction with other tests (e.g. bend, tensile, tensile creep, macro, etc.) to assess the performance of welded assemblies, made from thermoplastics materials.
The test is applicable to co-axial or co-planar heated tool butt welded assemblies made from thermoplastics materials filled or unfilled, but not reinforced. It is not applicable to tubular assemblies with a nominal outside diameter less than 90 mm.

This document specifies methods for determination of the ash of polyamides, both filled and unfilled. It follows the general procedures given in ISO 3451-1.

This document describes the background to methods for the determination of the thermal conductivity and thermal diffusivity of polymeric materials. Different techniques are available for these measurements and some can be better suited than others for a particular type, state and form of material. This document provides a broad overview of these techniques. Standards specific to these techniques, as referenced in this document, are used to carry out the actual test method.

This document specifies a method for the determination of the thermal diffusivity of a thin solid disc of plastics in the thickness direction by the light flash method. This method is based upon the measurement of the temperature rise at the rear face of the thin-disc specimen produced by a short energy pulse on the front face.
The method is applicable to homogeneous solid plastics as well as composites having an isotropic or orthotropic structure. In general, it covers materials having a thermal diffusivity, α, in the range 1 × 10−7 m2⋅s−1 < α < 1 × 10−4 m2⋅s−1. Measurements can be carried out in gaseous and vacuum environments over a temperature range from −100 °C to +400 °C.
NOTE          For inhomogeneous specimens, the measured values can be specimen thickness dependent.

This Technical Report identifies the quality related responsibilities and tasks included in the supervision of activities related to the welding of products and semi-finished products made of thermoplastic materials and provides guidelines to ensure the quality of the supervision.
The fundamental aspects of this Technical Report are the following:
- definition of tasks and responsibilities;
- definition of the required knowledge, skills and competence.
The plastic welding supervisor (PWS) should be employed by the organization involved in the welding activities. This Technical Report applies to all thermoplastic welding processes.

This document specifies a method for the determination of the thermal stability at elevated temperature of compounds and products based on vinyl chloride homopolymers and copolymers (in the following text abbreviated as PVC) which undergo dehydrochlorination (the evolution of hydrogen chloride).
This document is applicable to the characterization of PVC compounds and products, especially with regard to the effectiveness of their heat-stabilizing systems.
It is applicable to coloured PVC compounds and products where a discolouration test under the action of heat may be unsatisfactory.
This document is applicable to compounded PVC materials and products. It can be applicable to polymers in powder form under appropriate conditions, to be agreed upon between the interested parties.
This document does not apply to PVC compounds in the form of dry blends, since such materials can be not sufficiently homogeneous.
This document does not apply to PVC compounds and products which evolve other decomposition products, in addition to hydrogen chloride, at elevated temperatures that can affect the conductivity of water when they are absorbed into it. In this case, a method suitable for the determination of chloride ion (Cl−) in the absorbing solution shall be used (see ISO 182-4[2]).
This document can also be applied to other plastics materials which can evolve hydrogen chloride or other hydrogen halides when heated under the conditions prescribed by the relevant specifications, or as agreed upon between the interested parties.

This document specifies dimensional requirements relating to test specimens prepared from plastics materials intended for processing by moulding, as well as to test specimens prepared by machining from sheets or shaped articles. It compiles the designations and dimensions of test specimens used for the acquisition of comparable data and of other frequently used specimens.
The following types of test specimen are specified:
A            Tensile specimen, multipurpose or reduced-scale
B            Bar specimen
C            Small tensile specimen
D            Square plate specimen
F            Rectangular plate specimen
NOTE    If a particular type of test specimen is not mentioned in this document, this does not mean that there is any intention to exclude the use of the specimen. Additional specimen types can be added in future if they are commonly used.

1.1     This document 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 the ISO 179 series or ISO 180.
1.2     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.
1.3     These methods are applicable both to specimens prepared from moulding materials and to specimens taken from finished or semi-finished products (for example mouldings, laminates, or extruded or cast sheets).
1.4     Results obtained by testing moulded specimens of different dimensions are not necessarily the same. Equally, it is possible that specimens cut from moulded products will 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 can or can not be comparable.
1.5     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 document specifies a method for determining the plasticizer absorption at room temperature. It is applicable to PVC general-purpose resins and filler resins designated "G" and "F" in ISO 24024-1.
This document can be used to determine the quantity of plasticizer absorbed by a resin at room temperature to give a dry mixture.

1.1 This document specifies methods for determining the compressive properties, in directions
parallel to the plane of lamination, of fibre-reinforced plastic composites, based on thermosetting or
thermoplastic matrices. The compressive properties are of interest for specifications and qualitycontrol
purposes. The test specimens are machined from a flat test plate, or from suitable finished or
semi-finished products.
1.2 Two loading methods and two types of specimen are described.
The loading methods are:
— Method 1: provides shear loading of the specimen (gauge length unsupported)
— Method 2: provides combined loading of the specimen (gauge length unsupported)
NOTE For tabbed specimens loaded using method 2, load is transferred through a combination of endloading
and shear-loading through the tabs.
The specimen designs are:
— Type A specimen: rectangular cross-section, fixed thickness, end-tabbed (mainly for aerospace
style preimpregnates (~ 0,125 mm ply thickness)
— Type B specimen: rectangular cross-section, range of thicknesses, untabbed or end-tabbed, two
specimen sizes are available (B1 and B2).
The Type A specimen is used for unidirectionally or biaxially reinforced materials tested in the
fibre direction, where the fibres are normally either aligned continuous or aligned long (>7,5 mm)
discontinuous. The Type B1 and B2 specimens are used for multi-directional aligned; mat, fabric and
other multi-directionally reinforced materials where the fibre structure is more complex and/or
coarser.
1.3 This document gives criteria for checking that the combination of test method and specimen
design result in valid failures. It is noted that alternative test method/specimen combinations will not
necessarily give the same result.
1.4 The methods specify required dimensions for the specimen. Tests carried out on specimens of
other dimensions, or on specimens that are prepared under different conditions, can produce results
that are not comparable. Other factors, such as the speed of testing, the support fixture used and the
conditioning of the specimens, can influence the results.

This document specifies the classifications, requirements and test methods for unplasticized poly(vinyl chloride) (PVC-U) profiles covered with foils designed for external uses bonded with adhesives which are intended to be used for the fabrication of windows and doors.
NOTE 1   For editorial reasons, in this document, the term "window" is used for window/door.
NOTE 2   For the purpose of production control, test methods other than those specified in this document can be used.

This document specifies a method of determining the apparent density, i.e. the mass per unit of volume, of loose material (powder or granular material) that can be poured from a funnel of specified design.
NOTE            For a method of determining the apparent density of loose moulding material that cannot be poured from a specified funnel, see ISO 61.

This document specifies a method of determining the apparent density, i.e. the mass per unit of volume, of loose material that cannot be poured from a funnel of specified design.
NOTE            For a method of determining the apparent density of loose moulding material that can be poured from a specified funnel, see ISO 60.
This document is applicable to loose moulding materials such as slice, granular or powder.

This document specifies a method for the determination of volatile matter (predominantly water) in aminoplastic moulding materials, by drying in an oven.

This document describes the principles to be followed in the analysis of microplastics in various environmental matrices. This includes the unique particle size classification of plastics, the use of certain apparatus with regard to sampling, sample preparation, and the determination of representative sample quantities.
The purpose of this document is to specify minimum requirements until specific standards for the different case situations are available. This is important to ensure that the development of the specific standards is done on a consistent basis to ensure that comparison or correlation of results is possible.
This document does not include requirements for monitoring actions.

This document specifies a method suitable for the production control or product development purposes for assessing the heat release rate of essentially flat products exposed in the horizontal orientation to controlled levels of radiant heating with an external igniter. The heat release rate is determined by the use of a thermopile instead of the more accurate oxygen consumption techniques. The time to ignition and sustained flaming are also measured in this test. The mass loss of the test specimen can also be measured optionally.

This document specifies two calcination methods for the determination of the textile glass and mineral filler content of glass-reinforced plastics:
—     Method A: for the determination of the textile glass content when no mineral fillers are present.
—     Method B: for the determination of the textile-glass and mineral-filler content when both components are present.
This document is applicable to the following types of material:
—     prepregs made from yarns, rovings, tapes or fabrics;
—     SMC, BMC and DMC moulding compounds;
—     textile-glass-reinforced thermoplastic moulding materials and granules;
—     filled or unfilled textile-glass laminates made with thermosetting or thermoplastic resins.
The methods do not apply to the following types of reinforced plastic:
—     those containing reinforcements other than textile glass;
—     those containing materials which do not completely burn off at the test temperature (for example, those based on silicone resin);
—     those containing mineral fillers which degrade at temperatures below the minimum calcination temperature.

This document specifies a method of determining the degree of disintegration of plastic materials when exposed to a laboratory-scale composting environment. The method is not applicable to the determination of the biodegradability of plastic materials under composting conditions. Further testing is necessary to be able to claim compostability.

This document specifies two methods for determining the air flow value of flexible cellular polymeric materials:
—     method A, for conventional types of flexible cellular polymeric material;
—     method B, for all types of flexible cellular polymeric material, but especially for materials with a low permeability to air.
For method B, two methods are specified in this document:
—     method B1: with manual measurement;
—     method B2: with automatic measurement.
NOTE 1       Air flow values can be used to give an indication of the effects of formulation and production variables on the cellular structure.
NOTE 2       In this document, the expression “conventional type of flexible cellular polymeric material” means types which are unsuitable for sealing purposes.