CEN/TC 366/WG 2 - Physical characteristics

This document specifies a method for the determination of low specific surface area of powders ELTs rubber by measuring the amount of physically adsorbed krypton gas and applying the theoretical multipoint Brunauer, Emmett and Teller (BET) method.
This document defines a specific method for powders taking into account that, in order to obtain an accurate value of specific surface area, a representative sample of the material to be tested is taken according to the principle that every particle of the sample that represents the lot have an equal probability of being included in the sample.

The purpose of this document is to provide information about a procedure based on the determination of a visual index correlated with the content of textile fibres, which are free and bounded to the rubber, of granulates. This approach is currently used by Spanish grinders in order to control the efficiency of their processes and is effective for granulates with particle sizes the bottom limit of which is more than 0,5 mm, and upper limit less than 10 mm.
NOTE   Part of this document is also the presentation of a study carried by Valoriza Servicios Medioambientales and Geneus Canarias S.L.
A test procedure for the determination of a visual index of the content of the textile fibre of a granulate sample, which is free and bounded to the rubber, from the ELT’s processing is described in UNE 53936:2015 EX: Materials produced from end of life tyres. Rubber granulates.

This document specifies a method for obtaining a sample of rubber granulates or powders derived from End-of-life tyres which have been stored in big-bags.
Several sample increments at different levels within the big-bag are obtained, which represent the average particle size distribution within the big-bag. From these sample increments, a representative sample is derived.

This document sets out methods and test protocols used to determine the true density of granulates produced from ELTs based on water pycnometry.

This document specifies methods for obtaining a sample of rubber granulates or powders derived from end-of-life tyres which have been stored in big-bags and small-bags.
Sample increments at different levels within the bag are obtained, which represent the average particle size distribution within the bag. From these sample increments, a representative sample is derived.
The methods specified in this document are applicable, for example, when the samples are to be tested for e.g. bulk density, durability, particle size distribution, moisture content, ash content, ash melting behaviour, calorific value, chemical composition, impurities.

This document specifies methods and test protocols used to determine the true density of granulates and powders produced from ELTs, based on water pycnometry.
This document is applicable for powders and granulates below 12 mm.