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BS ISO 2476:2014 pdf free

BS ISO 2476:2014 pdf free.Butadiene rubber (BR)-Solution-polymerized types一Evaluation procedures
Five mixing procedures are specified, a procedure using a laboratory internal mixer is preferred.
– method A1: single-stage mixing using a laboratory internal mixer;
– method A2: two-stage mixing using a laboratory internal mixer for both initial and final mixing;
– method B: two-stage mixing using a laboratory internal mixer for initial mixing and a mill for final mixing.
The smaller laboratory internal mixers do not provide enough compound for the final mill mixing since a batch mass of four times the formula mass is required. In these cases, the laboratory internal mixer should be used for the final mixing. The mixer head starting temperature or the batch mass can be adjusted, so that the final temperature of the discharged batch does not exceed 120 °C.
– method C1 and C2: mill mixing.
NOTE 1 These procedures can give different results.
NOTE 2 Mill mixing of solution-polymerized butadiene rubbers is more difficult than with other rubbers, and mixing is best accomplished by using an internal mixer. With some types of butadiene rubber, it is not possible to obtain a satisfactory mix using a mill-mixing procedure.
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. 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 a specified temperature (60 °C has been found to be
suitable) 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.
NOTE 1 The mixing conditions given in Table A.Z for various sizes of laboratory internal mixer might be helpful.BS ISO 2476 pdf download.

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