Plast: allmänt

ISO 4892-2:2013 specifies methods for exposing specimens to xenon-arc light in the presence of moisture to reproduce the weathering effects (temperature, humidity and/or wetting) that occur when materials are exposed in actual end-use environments to daylight or to daylight filtered through window glass.

This document specifies the requirements for the laboratory testing of the resistivity of specially prepared specimens of plastics rendered conductive by the inclusion of carbon black. The test is suitable for materials of resistivity less than 106 Ω⋅cm (104 Ω⋅m). The result is not strictly a volume resistivity, because of surface conduction, but the effects of the latter are generally negligible.

This document specifies the general terms and definitions relevant for the utilisation of thermoplastics recyclates in thermoplastics pipes, fittings and ancillaries for both pressure and non-pressure piping systems.
This document is intended to be used by specification writers in conjunction with prCEN/TR 14541-2 and prCEN/TR 14541-3 when preparing normative documents under the scope of CEN/TC 155.

This part of ISO 13741 specifies a method for the determination of residual monomers and other (saturated) organic components in aqueous polymer dispersions and latices as well as in related products. It makes use of capillary-column gas chromatography with direct injection of the liquid sample.
Residual monomers and saturated volatiles that have been successfully determined by this method include acrylic and methacrylic esters, acrylonitrile, butadiene, styrene, vinyl acetate, vinyl chloride as well as by-products such as acetaldehyde and ethylbenzene. Butadiene could be co-eluted with cis-2-butene.
NOTE N-butyl acrylate and dibutyl ether cannot be separated with DB1 column. In this case use DB5 column.
Since the chromatograms obtained normally contain a series of peaks, it is only possible to determine the content of those volatiles for which response factors have been determined. For the identification of unknown peaks including SVOC (semi volatile organic compounds), auxiliary methods like mass spectroscopy or the use of a second GC column with a different polarity are advisable. Toluene equivalent can also be used for the alternative quantification method of unknown peaks.

This document specifies a method for the measurement of haze, an optical property resulting from wide-angle scattering of light, in transparent and substantially colourless plastics. This method is applicable to the measurement of haze values of less than 40 %.
NOTE The haze of abraded or matted transparent plastics can be measured, but the value obtained may be erroneously lower than the true value due to light scattering within a narrow angle.

This document specifies two test methods for determining the refractive index of plastics, namely:
— Method A: a refractometric method for measuring the refractive index of moulded parts, cast or extruded sheet or film, by means of a refractometer. It is applicable not only to isotropic transparent, translucent, coloured or opaque materials but also to anisotropic materials.
— Method B: an immersion method (making use of the Becke line phenomenon) for determining the refractive index of powdered or granulated transparent materials by means of a microscope. Monochromatic light should, in general, be used to avoid dispersion effects.
NOTE 1 The refractive index is a fundamental property which can be used for checking purity and composition, for the identification of materials and for the design of optical parts. The change in refractive index with temperature can give an indication of transition points of materials.
NOTE 2 The accuracy of method B is approximately the same as that of method A when an experienced operator uses the method with extreme care.

This document specifies two methods for evaluating the melting behaviour of semi-crystalline polymers.
Melting temperatures determined by the different methods usually differ by several kelvins for the reasons explained in the introduction.
Method A: Capillary tube
This method is based on the changes in shape of the polymer. It is applicable to all semi-crystalline polymers and their compounds.
NOTE 1 Method A can also be useful for the evaluation of the softening of non-crystalline solids.
Method B: Polarizing microscope
This method is based on changes in the optical properties of the polymer. It is applicable to polymers containing a birefringent crystalline phase. It may not be suitable for plastics compounds containing pigments and/or other additives which could interfere with the birefringence of the polymeric crystalline zone.
NOTE 2 Another method applicable to semi-crystalline polymers is described in ISO 11357-3, Plastics — Differential scanning calorimetry (DSC) — Part 3: Determination of temperature and enthalpy of melting and crystallization.

This document covers the determination of the total luminous transmittance, in the visible region of the spectrum, of planar transparent plastics and substantially colourless plastics, using a double-beam scanning spectrophotometer. This document cannot be used for plastics which contain fluorescent materials.
This document is applicable to transparent moulding materials, films and sheets not exceeding 10 mm in thickness.
NOTE 1 Total luminous transmittance can also be determined by a single-beam instrument as in ISO 13468-1.
NOTE 2 Substantially colourless plastics include those which are faintly tinted.
NOTE 3 Specimens more than 10 mm thick can be measured provided the instrument can accommodate them, but the results cannot be comparable with those obtained using specimens less than 10 mm thick.

This document provides a method for assessing the very early oxidative degradation state of polymers during outdoor weathering and indoor accelerated weathering tests and the influence of various additives can also be evaluated.
This method is based on an analytical method in which the degree of progress of the oxidative degradation reaction of a polymer is sensitively detected by measurement of Chemically Induced UPE (ultra-weak photon emission).