BS ISO 15825:2017 pdf download

BS ISO 15825:2017 pdf download.Rubber compounding ingredients — Carbon black — Determination of aggregate size distribution by disc centrifuge photosedimentometry
1 Scope
This document specifies a method for determining the size distribution of carbon black aggregates,using a disc centrifuge photosedimentometer. This technique is based on the hydrodynamic behaviour of carbon black in a centrifugal field. The determination of the aggregate size distribution is important in the evaluation of carbon black used in the rubber industry.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 1124, Rubber compounding ingredients — Carbon black shipment sampling procedures
ISO 3696, Water for analytical laboratory use — Specification and test methods
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1 General terms
3.1.1 carbon black aggregate
discrete, rigid colloidal entity that is the smallest dispersible unit in a suspension
Note 1 to entry: It is composed of extensively coalesced particles.
3.1.2 spin
fluid
inert liquid injected into the disc prior to the sample, through which aggregates sediment
Note 1 to entry: Alkaline conditions minimize agglomeration of dispersed aggregates in most cases.
3.1.3 dispersion fluid
liquid in which aggregates are dispersed
3.1.5
particle density
density of the aggregate in Mg/m 3
Note 1 to entry: For carbon black, 1,86 × 10 3 kg/m 3 (1,86 g/cm 3 ) is used as a typical value.
3.2 Terms concerning aggregate dimensions
3.2.1 Stokes diameter
D st
diameter of a sphere which sediments in a viscous medium in a centrifugal or gravitational field according to the Stokes equation
Note 1 to entry: A non-spherical object, such as a carbon black aggregate, may also be represented in terms of an equivalent Stokes diameter if it is considered as behaving as a smooth, rigid sphere of the same density and with the same sedimentation rate as the object.
Note 2 to entry: For carbon black, Stokes diameter is expressed in nanometres (nm).
3.2.2 mean diameter
average diameter
D mean
average diameter calculated from the differential mass distribution curve
Note 1 to entry: It represents the first moment of the differential distribution.