ISO 2476:1996 pdf download – Rubber, butadiene (BR) – Solution-polymerized types – Evaluation procedures
1 Scope
This International Standard specifies
– physical and chemical tests on raw rubbers;
– standard materials, standard test formulations,equipment and processing methods for evalu- ating the vulcanization characteristics of solution-polymerized butadiene rubbers (BR), including oil-extended types (OEBR), and the tensile stress-strain properties of vulcanized mixes.
2 Normative references
The following standards contain provisions which,through reference in this text, constitute provisions of this International Standard. At the time of publication,the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to in-vestigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain registers of currently valid In-ternational Standards.
IS0 37: 1994, Rubber, vulcanized or thermoplastic – Determination of tensile stress-s train properties.
IS0 247:1990, Rubber – Determination of ash.
IS0 248:1991, Rubbers, raw – Determination of volatile-matter content.
a) Cool the internal mixer to a temperature of 40 °C+5 °C with full cool- ing water on the rotors. Start the motor and raise the ram.
b) Leave the cooling water on and the steam off. Roll all the sulfur and the TBBS into one-half of the mas- terbatch and load into the mixer Add the remaining portion of the masterbatch L ower the ram.
c) Allow the batch to mix until a temperature of 110 °C or a total time of 3 min is reached, whichever occurs first.
d) Immediately pass the batch through a laboratory mill with a mill opening set at 0,8 mm and at a temperature of 50 °C+5 °C.
e) Pass the rolled batch endwise through the rolls six times.
f) Sheet the batch to approximately 6 mm Check- weigh the batch (see ISO 2393). If the mass of the batch differs from the theoretical value by more than + 0,5 % or – 1,5 %, discard the batch and re-mix. Remove sufficient material for cure- meter testing.
g) Sheet the batch to approximately 2.2 mm for preparing test sheets or to the appropriate thick- ness for preparing ISO ring specimens in accord- ance with ISO 37.
5.2.2.2.2 Stage 2 – Final mill mixing procedure
Cut 720,0 g (in the case of non-oil-extended rubber) or 660,0 g (in the case of oil-extended rubber containing 37,5 % oil) from the masterbatch. Weigh out four times the formula mass of the curatives (i.e. 6,0 g of sulfur, 3,6 g of TBBS, etc.). A good rolling bank at the nip of the rolls shall be maintained during mixing. If this is not obtained with the nip settings specified hereunder, make small ad- justments to the mill openings.