BS ISO 4658:2020 pdf download.Acrylonitrile-butadiene rubber (NBR) — Evaluation procedure.
4 Sampling and sample preparation
4.1 Take a sample of mass approximately 1,5 kg by the method described in ISO 1795.
4.2 Prepare the test portion in accordance with ISO 1795.
5 Physical and chemical tests on raw rubber
5.1 Mooney viscosity
Determine the Mooney viscosity in accordance with ISO 289-1, on a test portion prepared as indicated in 4.2. Record the result as M L (1+4) at 100 °C.
5.2 Volatile matter
Determine the volatile matter content by the method specified in ISO 248-1 or ISO 248-2.
5.3 Ash
Determine the ash in accordance with ISO 247-1 or ISO 247-2.
6 Preparation of the test mix for evaluation
6.1 Standard test formulation
The standard test formulation is given in Table 1.
The materials shall be national or international standard reference materials, unless no standard
reference materials are available in which case the materials to be used shall be agreed between the interested parties.
6.2 Equipment and procedure
Equipment and the procedure for preparation, mixing and vulcanization shall be in accordance with ISO 2393.
6.3 Mixing procedures
6.3.1 General
The three following alternative mixing procedures are specified:
— method A1: single stage mixing with LIM (laboratory internal mixer) which is the preferred method;
— method A2: two stage mixing using a LIM for initial mixing and mill mixing for final mixing;
— method B: mill mixing.
9 Precision
See Annex A.
10 Test report
The test report shall include the following information:
a) a reference to this document including its year of publication, i.e. ISO 4658:2020;
b) all details necessary for the identification of the sample;
c) the procedure used to prepare the standard test formulation;
d) the reference materials used;
e) the sampling method for Mooney viscosity measurement (milled or un-milled);
f) the method used to determine the volatile-matter content (ISO 248-1or ISO 248-2);
g) the method used to determine the ash (ISO 247-1 or ISO 247-2);
h) the time used to measure M H in Clause 7;
i) the curemeter method used in Clause 7 (ISO 6502-2 or ISO 6502-3);
j) the vulcanization temperature and times used in Clause 8;
k) any unusual features noted during the determination;
l) any operation not included in this document or in the International Standards to which reference is made, as well as any operation regarded as optional;
m) the results and the units in which they have been expressed;
n) the date of the test.BS ISO 4658 pdf download.