Plast

Kommittébeteckning: SIS/TK 156 (Plast)
Källa: CEN
Svarsdatum: den 13 feb 2018
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This document specifies a method for exposing specimens made from poly(vinyl chloride) (PVC) based profiles to xenon-arc radiation, in order to assess changes in characteristics.

It is applicable to PVC based profiles including those covered with foil, lacquered or coextruded.

NOTE The determination of changes in colour and variations of properties after exposure of PVC based profiles to xenon-arc radiation is described in an informative Annex A.

Ämnesområden: Plast: allmänt
Kommittébeteckning: SIS/TK 156 (Plast)
Källa: ISO
Svarsdatum: den 21 feb 2018
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This International Standard describes three methods for the exposure of plastics in a marine environment. Method A covers exposures where specimens float on the surface, method B covers exposures where specimens are partially immersed and method C covers exposures where specimens are completely immersed. Although intended for marine (salt water) exposure, the methodology might be used with outdoor brackish water and fresh-water exposures as well. Direct weathering of plastics on land is described in ISO 877.

Method A is particularly applicable to enhanced-degradability plastics where the environmental degradation under marine floating exposure is expected to be accelerated relative to that of regular plastic materials.

This International Standard specifies the general requirements for the apparatus, and procedures for using the test methods described.

It lists properties that may be used to evaluate changes in plastics subjected to marine exposure. More specific information about methods for determining the changes in properties of plastics on exposure and reporting these results is given in ISO 4582.

Ämnesområden: Termoplastmaterial
Kommittébeteckning: SIS/TK 156 (Plast)
Källa: CEN
Svarsdatum: den 7 mar 2018
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This International Standard specifies a method for the determination of the viscosity number of dilute solutions of polyamides in certain specified solvents.

Polyamide samples must be completely soluble in the solvents mentioned. Additives such as flameretardants and modifiers often interfere with the viscosity measurement, having an increasing effect on the viscosity number in formic acid and a decreasing effect on the viscosity number in sulfuric acid. The extent of the effect for polyamide compounds depends on the additive, the quantity of the additive, the presence of other additives and the compounding conditions.

For pure polyamides or polyamides containing additives that do not interfere with the viscosity measurement, the determination of the viscosity number of a polyamide provides a measure of the molecular mass of the polymer. The viscosity number of pure polyamides or polyamides which contain additives that do not interfere with the viscosity measurement can be converted from one solvent to another.

The viscosity number of polyamides containing additives that do interfere with the viscosity measurement is specific to the solvent used and the material composition. In this case, the measured viscosity number cannot be converted from one solvent to another.

The method is applicable to the polyamides designated PA 46, PA 6, PA 66, PA 69, PA 610, PA 612, PA 11, PA 12, PA 6T/66, PA 6I/6T, PA 6T/6I/66, PA 6T/6I, PA 6I/6T/66 and PA MXD6 as defined in ISO 1874-1, as well as to copolyamides, compounds of polyamides and other polyamides that are soluble in one of the specified solvents under the specified conditions.

The method is not applicable to polyamides produced by anionic polymerization of lactams or produced with cross-linking agents; such polyamides are normally insoluble in the specified solvents.

The viscosity number is determined by the general procedure specified in ISO 1628-1, observing the particular conditions specified in this International Standard.