ISO 1658-2015 pdf free download

ISO 1658-2015 pdf free download.Natural rubber (NR) — Evaluation procedure Caoutchouc naturel (NR) — Méth ode d’évaluation.
g) Cut sufficient material from the batch for curemeter testing and, if required, for determination of the Mooney viscosity of the unvulcanized batch in accordance with ISO 289-1. Sheet the batch to approximately 2,2 mm for preparing test slabs or to the appropriate thickness for preparing ISO ring test pieces.
h) Condition the batch for 2 h to 24 h after mixing and prior to vulcanizing, if possible at standard temperature and humidity as defined In ISO 23529.
5.3.3 Mill mixing procedure for formulae I and 2 (gum compounds) using masterbatches
Compounding materials such as accelerators, sulfur or fillers can be incorporated into the rubber as masterbatches. This technique improves the accuracy of compounding-material incorporation and is also more convenient.
The procedure for preparing masterbatches and test mixes for the gum compounds is given in Annex A.
5.3.4 Mixing procedures for formula 3 (black-filled compound)
5.3.4.1 Mill mixing
5.3.4.1.1 Measurement of rapid plasticity number
Load the rubber on to the mill with the mill opening set at 0,5 mm. Masticate until a smooth band and rolling bank are obtained.
After mastication, determine the rapid plasticity number in accordance with ISO 2007. The rapid plasticity number shall not exceed 45, which is approximately equivalent to a viscosity of 70 Mooney units determined in accordance with ISO 289-i.
5.3.4.1.2 Mixing
The standard laboratory mill batch mass, in grams, shall be four times the formulation batch mass (i.e.
144,95 g x 4, = 579,8 g, for formula 3). Maintain the surface temperature of the rolls at 70 °C ± 5 °C and
a good rolling bank at the nip of the rolls during mixing. If this is not obtained with the nip settings
specified hereunder, small adjustments to the mill openings may be necessary.
g) Check the mass of the batch. If the mass of the batch differs from the theoretical value by more than + 0,5 % or — 1,5 %, discard the batch and remix.
h) Cut sufficient material from the batch for curemeter testing and, if required, for determination of the Mooney viscosity of the unvulcanized batch in accordance with ISO 289-1. Sheet the batch to approximately 2,2 mm for preparing test slabs or to the appropriate thickness for preparing ISO ring test pieces.
i) Condition the batch for 2 h to 24 h after mixing and prior to vulcanizing, if possible at standard temperature and humidity as defined in ISO 23529.
5.3.4.2 Mixing using a laboratory internal mixer (LIM)
5.3.4.2.1 General
For laboratory internal mixers having nominal capacities of 65 cm3 to about 2 000 cm3, the batch mass shall be equal to the nominal mixer capacity, in cubic centimetres, multiplied by the density of the compound, in grams per cubic centimetre. This means that, if the laboratory internal mixer has a nominal capacity of 750 cm3, the batch mass for formula 3 is 750 x 1,103 g (= 827,25 g).
For each batch mixed during the preparation of a series of identical mixes, the laboratory internal mixer conditions shall be the same. At the beginning of each series of test mixes, a machine-conditioning batch shall be mixed using the same formulation as the mixes under test. The laboratory internal mixer shall be allowed to cool down to 60°C between the end of one test batch and the start of the next. The temperature setting shall not be altered during the mixing of a series of test batches.
5.3.4.2.2 Single-stage mixing
The mixing technique shall be such as to obtain a good dispersion of all the ingredients.
The final temperature of the batch discharged after mixing shall not exceed 120 °C. If necessary, adjust the batch mass or the head temperature so that this condition is met.
NOTE 1 The mixing conditions given In Tabiefl.5 for each size of laboratory internal mixer may be helpful.
NOTE 2 Compounding materials other than rubber, carbon black and oil can be added to laboratory internal mixer batches more precisely and with greater ease if they are previously blended together in the proportions required by the formulation. Such blends can be made using a mortar and pestle, by mixing for 10 mm in a biconical blender with intensifier bar turning, or by mixing in a blender for five 3 s periods and scraping the inside of the blender to dislodge materials stuck to the sides after each 3 s mix. A Waring blender has been found suitable for this method. Caution: if mixed for longer than 3 s, the stearic acid can melt and prevent good dispersion.
An example of a mixing procedure for a laboratory internal mixer is given in a) to h) hereafter.ISO 1658-2015 pdf free download.