Plast: allmänt

This European Standard specifies the vocabulary, methods for characterization, and templates for reporting about bio-based polymers, plastics, and plastic products (including semi-finished plastic products and composites).

In particular this European Standard covers: terminology, bio-based content, bio-based carbon content, Life Cycle Assessment, sustainability aspects, and declaration tools.

Biocompatible polymers and plastics for medical applications covered by specific provisions are out of the scope of this European Standard.

The various parts of ISO 6721 specify methods for the determination of the dynamic mechanical properties of rigid plastics within the region of linear viscoelastic behaviour. This part of ISO 6721 is an introductory section which includes the definitions and all aspects that are common to the individual test methods described in the subsequent parts.

Different deformation modes may produce results that are not directly comparable. For example, tensile vibration results in a stress which is uniform across the whole thickness of the specimen, whereas flexural measurements are influenced preferentially by the properties of the surface regions of the specimen.

Values derived from flexural-test data will be comparable to those derived from tensile-test data only at strain levels where the stress-strain relationship is linear and for specimens which have a homogeneous structure.

This part of ISO 6721 specifies two methods (A and B) for determining the linear dynamic mechanical properties of plastics, i.e. the storage and loss components of the torsional modulus, as a function of temperature, for small deformations within the frequency range from 0,1 Hz to 10 Hz.

NOTE The temperature dependence of these properties, measured over a sufficiently broad range of temperatures (for example from −50 °C to +150 °C for most commercially available plastics), gives information on the transition regions (for example the glass transition and the melting transition) of the polymer. It also provides information concerning the onset of plastic flow.

The two methods described are not applicable to non-symmetrical laminates (see ISO 6721-3, Plastics — Determination of dynamic mechanical properties — Part 3: Flexural vibration — Resonance-curve method). The methods are not suitable for testing rubbers, for which the user is referred to ISO 4664-2, Rubber, vulcanized or thermoplastic — Determination of dynamic properties — Part 2: Torsion pendulum methods at low frequencies.

This part of ISO 6721 describes a forced, non-resonance method for determining the components of the tensile complex modulus E* of polymers at frequencies typically in the range 0,01 Hz to 100 Hz.

NOTE Higher frequency measurements can be made, but significant errors may be obtained in the dynamic properties measured (see 10.2.2 and 10.2.3).

The method is suitable for measuring dynamic storage moduli in the range 0,01 GPa to 5 GPa. Although materials with moduli outside this range may be studied, alternative modes of deformation should yield higher accuracy [i.e. a shear mode for G′ < 0,01 GPa (see ISO 6721-6) and a flexural mode for E′ > 5 GPa (see ISO 6721-3 or ISO 6721-5)].

This method is particularly suited to the measurement of loss factors bigger than 0,02 and may therefore be conveniently used to study the variation of dynamic properties with temperature and frequency through most of the glass-rubber relaxation region (see ISO 6721-1). The availability of data determined over wide ranges of both frequency and temperature enables master plots to be derived, using frequencytemperature shift procedures, which display dynamic properties over an extended frequency range at different temperatures.

This part of ISO 6721 describes a flexural, non-resonance method for determining the components of the flexural complex modulus Ef* of polymers at frequencies typically in the range 0,01 Hz to 100 Hz. Higherfrequency measurements can be made, but significant errors may be obtained in the dynamic properties measured (see 10.2.2 and 10.2.3). The method is suitable for measuring dynamic storage moduli in the range 10 MPa to 200 GPa.

NOTE Although materials with moduli less than 10 MPa may be studied, more accurate measurements of their dynamic-mechanical properties can be made using shear modes of deformation (see ISO 6721-6).

This method is particularly suited to the measurement of loss factors greater than 0,02 and may therefore be conveniently used to study the variation of dynamic properties with temperature and frequency through most of the glass-rubber relaxation region (see ISO 6721-1). The availability of data determined over wide ranges of both frequency and temperature enables master plots to be derived, using frequency/temperature shift procedures, which present dynamic properties over an extended frequency range at different temperatures.

This part of ISO 6721 describes a forced, non-resonance method for determining the components of the shear complex modulus G* of polymers at frequencies typically in the range 0,01 Hz to 100 Hz. Higherfrequency measurements can be made, but significant errors may be obtained in the dynamic properties measured (see 10.2.2 and 10.2.3). The method is suitable for measuring dynamic storage moduli in the range 0,1 MPa to 50 MPa.

NOTE Although materials with moduli greater than 50 MPa may be studied, more accurate measurements of their dynamic shear properties can be made using a torsional mode of deformation (see parts 2 and 7 of ISO 6721).

This method is particularly suited to the measurement of loss factors greater than 0,02 and may therefore be conveniently used to study the variation of dynamic properties with temperature and frequency through most of the glass-rubber relaxation region (see ISO 6721-1). The availability of data determined over wide ranges of both frequency and temperature enables master plots to be derived, using frequency/temperature shift procedures, which display dynamic properties over an extended frequency range at different temperatures.

This part of ISO 6721 describes a torsional, non-resonance method for determining the components of the shear complex modulus G* of solid polymers in the form of bars or rods at frequencies typically in the range 0,001 Hz to 100 Hz. Higher-frequency measurements can be made, but significant errors may be obtained in the dynamic properties measured (see 10.2.1 and 10.2.2). The method is suitable for measuring dynamic storage moduli ranging from about 10 MPa, which is typical of values obtained for stiff rubbers, to values of about 10 GPa which are representative of fibre-reinforced plastics. Although materials with moduli less than 10 MPa may be studied, more accurate measurements of their dynamic properties can be made using simple shear (see ISO 6721-6) or torsional deformations of thin layers between parallel plates.

This method is particularly suited to the measurement of loss factors greater than 0,02 and may therefore be conveniently used to study the variation of dynamic properties with temperature and frequency through most of the glass-rubber relaxation region (see ISO 6721-1). The availability of data determined over wide ranges of both frequency and temperature enable master plots to be derived, using frequencytemperature shift procedures, which display dynamic properties over an extended frequency range at different temperatures.

NOTE Although loss factors below 0,1 may be more accurately determined using the torsion pendulum (see ISO 6721-2), the method described in this part of ISO 6721 enables a much wider and continuous frequency range to be covered.

This document specifies a method for the determination of the penetration temperature of thermoplastics using thermomechanical analysis.

NOTE This method can also be used to measure the softening point.

This document specifies the general principles of a method, using an inclined-tube falling-ball viscometer, for determining the viscosity of polymers and resins in the liquid emulsified or dispersed state. It is intended for application to liquids over a viscosity measurement range of 0,6 mPa·s to 250 000 mPa s (temperature range −20 °C to +120 °C) for which the shear stress and shear rate are proportional, i.e. the viscosity is independent of the shear rate. This ideal behaviour is commonly known as Newtonian behaviour. If a liquid differs significantly from this behaviour, different results can be obtained with the different balls of a falling-ball viscometer or from viscometers with different geometries, such as capillary and rotational viscometers.

This International Standard specifies methods for determining the deterioration of plastics due to the action of fungi and bacteria and soil microorganisms. The aim is not to determine the biodegradability of plastics.

The type and extent of deterioration may be determined by

a) visual examination

and/or

b) changes in mass

and/or

c) changes in other physical properties.

The tests are applicable to all plastics that have an even surface and that can thus be easily cleaned. The exceptions are porous materials, such as plastic foams.

This International Standard uses the same test fungi as IEC 60068-2-10. The IEC-method, which uses so-called "assembled specimens", calls for inoculation of the specimens with a spore suspension, incubation of the inoculated specimens and assessment of the fungal growth as well as any physical attack on the specimens.

The volume of testing and the test strains used will depend on the application envisaged for the plastic. These parameters should therefore be agreed upon before the tests and should be stated in the test report.

This document specifies three methods for the determination of the density of non-cellular plastics in the form of void-free moulded or extruded objects, as well as powders, flakes and granules.

— Method A: Immersion method, for solid plastics (except for powders) in void-free form.

— Method B: Liquid pyknometer method, for particles, powders, flakes, granules or small pieces of finished parts.

— Method C: Titration method, for plastics in any void-free form.

NOTE This document is applicable to pellets as long as they are void-free. Density is frequently used to follow variations in physical structure or composition of plastic materials. Density might also be useful in assessing the uniformity of samples or specimens. Often, the density of plastic materials will depend upon the choice of specimen preparation method. When this is the case, precise details of the specimen preparation method will have to be included in the appropriate material specification. This note is applicable to all three methods.

This document specifies a gradient column method for the determination of the density of non-cellular moulded or extruded plastics in void-free form. Density gradient columns are columns containing a mixture of two liquids, the density in the column increasing uniformly from top to bottom.

NOTE This document is applicable to pellets as long as they are void-free. Density is frequently used to follow variations in physical structure or composition of plastic materials. Density may also be useful in assessing the uniformity of samples or specimens. Often the density of plastic materials will depend upon the choice of specimen preparation method. When this is the case, precise details of the specimen preparation method will have to be included in the appropriate material specification.

This International Standard is used to determine the degree of disintegration of plastic materials in a pilot-scale aerobic composting test under defined conditions. It forms part of an overall scheme for the evaluation of the compostability of plastics as outlined in ISO 17088. The test method laid down in this International Standard can also be used to determine the influence of the test material on the composting process and the quality of the compost obtained. It cannot be used to determine the aerobic biodegradability of a test material. Other methods are available for this (e.g. see ISO 14851, ISO 14852 or ISO 14855-1 and ISO 14855-2.

This International Standard specifies proper methods for measuring antiviral activity on plastics and other non-porous surfaces of antiviral-treated products.

Test Viruses used in this International Standard are as follows:

— Influenza: An enveloped virus known to cause respiratory tract infection in humans.

— Feline calicivirus: A non-enveloped virus used in place of noroviruses known to cause enteric pathogens due to similar biological properties.

This document specifies a general method for determining the average molecular weight and the molecular weight distribution of polymers using SEC-LS, i.e. size-exclusion chromatography coupled with light-scattering detection. The average molecular mass and the molecular mass distribution are calculated from molecular weight data and weight concentrations determined continuously with elution time. The molecular weight at each elution time is determined absolutely by combining a light-scattering detector with a concentration-sensitive detector. Therefore, SEC-LS is classified as an absolute method.

For the applicability of the method, see ISO 16014-1:—, Clause A.1.

This part of ISO 6721 describes an ultrasonic wave propagation method for determining the storage components of the longitudinal complex modulus L* and the shear complex modulus G* of polymers at discrete frequencies typically in the range 0,5 MHz to 5 MHz. The method is suitable for measuring materials with storage moduli in the range 0,01 GPa to 200 GPa and with loss factors below 0,1 at around 1 MHz. With materials that have a higher loss, significant errors in velocity measurement are introduced through waveform distortion and can only be reduced using procedures that are outside the scope of this standard.

The method allows measurements to be made on small specimens, typically 50 mm × 20 mm × 5 mm, or small regions of larger specimens or sheets. It is therefore possible to obtain information on the homogeneity or anisotropy (see 10.5) of modulus in a specimen.

This part of ISO 6721 describes a pulse propagation method for determining the storage component of the complex tensile modulus E' of polymers at discrete frequencies typically in the range 3 kHz to 10 kHz. The method is suitable for measuring materials with storage moduli in the range 0,01 GPa to 200 GPa and with loss factors below 0,1 at around 10 kHz. With materials having a higher loss, significant errors in velocity measurement are introduced through decay of amplitude.

The method allows measurements to be made on thin films or fine fibres and long specimens, typically tapes of 300 mm × 5 mm × 0,1 mm or fibres of 300 mm × 0,1 mm (diameter).

This method may not be suitable for cellular plastics, composite plastics and multilayer products.

This document specifies general methods, with suitable test conditions, for the determination of the ash of a range of plastics (resins and compounds). The particular conditions chosen may be included in the specifications for the plastic material in question.

Particular conditions applicable to poly(alkylene terephthalate) materials, unplasticized cellulose acetate, polyamides and poly(vinyl chloride) plastics, including some specific filled, glass-fibre-reinforced and flame-retarded materials, are specified in ISO 3451-2, ISO 3451-3, ISO 3451-4 and ISO 3451-5.