BS ISO 2302:2020 pdf free.Isobutene-isoprene rubber (IIR)一Evaluation procedure.
BS ISO 2302 For laboratory internal mixers having a nominal capacity 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. For each batch mixed, the laboratory internal mixer conditions shall be the same during the preparation of a series of identical mixes. 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 control conditions shall not be altered during the mixing of a series of test batches. The mixing technique shall be such as to obtain a good dispersion of all the ingredients. The temperature of the batch discharged on completion of mixing shall not exceed 120 °C. If necessary, adjust the batch mass or the mixer head starting temperature so that this condition is met In the following procedure, compounding materials other than rubber and carbon black, may be added to the batch more precisely and with greater ease if they are previously blended together in the proportions required by the formulation. Such blends may be made using one of the following: a mortar and pestle; a double-cone mixer (mix for 10 min with the intensifier bar turning); a blender (mix for five periods of 3 s each, scraping the inside of the blender to dislodge material stuck to the sides after each 3 s period) (a “Waring”-type blender has been found suitable for this method). If required, sheet the batch to approximately 2,2 mm for preparing test sheets or to the appropriate thickness for preparing ISO ring or dumbbell test pieces in accordance with ISO 37. To obtain the effects of mill direction, pass the folded batch four times between mill rolls set at50 °C士5 °C  and at the appropriate mill opening. Cool on a flat, dry surface. BS ISO 2302 pdf download.