ASTM D3958-06(R2021) pdf free download

ASTM D3958-06(R2021) pdf free download.Standard Test Methods for Rubber—Evaluation of BIIR and CIIR (Halogenated Isobutene—Isoprene Rubber)
1. Scope
1.1 These test methods cover the standard materials, test formula, mixing procedures, and test methods for the evalua- tion of halogenated isobutene-isoprene rubbers (BIIR and CIIR). 1.2 Both mill and miniature internal mixer procedures are given. 1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.5 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
6. Mixing Procedures
6.1 For general mixing procedures, refer to Practice D3182. 6.1.1 The compound may be prepared either on a mill, in a miniature internal mixer, or a lab internal mixer, although slightly different results may be obtained. 6.2 Mixing Cycles: 6.2.1 Method A: Mill Mix—See Table 2. 6.2.1.1 Mix with the mill roll temperature maintained at 40 6 5°C (104 6 9°F). The indicated mill openings should be maintained insofar as possible to provide a standard for uniform breakdown of the rubber due to milling. Necessary adjustments may be made to maintain a good working bank at the nip of the rolls.6.2.1.2 Condition the carbon black in accordance with 5.6 of Practice D3182. This is critical with halogenated IIR when the simple zinc oxide cure is used. 6.2.1.3 After mixing according to Table 2, measure and record the batch mass. Ifit differs from the theoretical value by more than 0.5 %, discard the batch. 6.2.1.4 If required, cut samples from the batch to allow testing ofcompound viscosity and processability in accordance with Test Methods D1646 or D6204, and vulcanization char- acteristics in accordance with Test Methods D2084 or D5289. 6.2.1.5 If tensile stress strain tests are required, sheet off to a finished thickness of approximately 2.2 mm (0.087 in.) and condition the compound according to Practice D3182. 6.2.2 Method B: Miniature Internal Mixer (MIM) Mix—See Table 3. 6.2.2.1 Mix with the head temperature of the miniature internal mixer maintained at 60 6 3°C (140 6 5°F) and the empty chamber rotor rotational frequency at 1 to 1.05 r/s (60 to 63 rpm). 6.2.2.2 Condition the carbon black in accordance with 5.6 of Practice D3182. This is critical with halogenated butyl rubber when the simple zinc oxide cure is used. 6.2.2.3 After mixing according to Table 3, turn off the motor, raise the ram, remove the head, and discharge the batch. Record the batch temperature. 6.2.2.4 Immediately pass the discharge from the mixer twice through a standard mill maintained at 40 6 5°C (104 6 9°F) with a roll separation of 0.5 mm (0.020 in.) once, then twice at a separation of 3 mm (0.12 in.) in order to dissipate heat. Pass the rolled batch endwise through the mill six times with an opening of0.8 mm (0.31 in.) to enhance the dispersion. 6.2.2.5 Measure and record the batch mass. Ifit differs from the theoretical value by more than 0.5 %, discard the batch. 6.2.2.6 If required, cut samples from the batch to allow testing ofcompound viscosity and processability in accordance with Test Methods D1646 or D6204, and vulcanization char- acteristics in accordance with Test Methods D2084 or D5289. 6.3.2 Mixing Cycle-Initial Mix—See Table 4. 6.3.2.1 After mixing according to Table 4, determine and record the batch mass; if the mass differs by more than 0.5 % of the theoretical mass, discard the batch. 6.3.2.2 Pass the batch immediately through the standard laboratory mill three times, set at 6.0 mm (0.25 in.) and 40 6 5°C (104 6 9°F). 6.3.2.3 Allow the batch to rest for 1 to 24 h. 6.3.3 Final Mix—See Table 5. 6.3.3.1 After mixing according to Table 5, measure and record the batch mass. Ifit differs from the theoretical value by more than 0.5 %, discard the batch. 6.3.3.2 If required, cut samples from the batch to allow testing ofcompound viscosity and processability in accordance with Test Methods D1646 or D6204, and vulcanization char- acteristics in accordance with Test Methods D2084 or D5289. 6.3.3.3 If tensile stress strain tests are required, sheet off to a finished thickness of approximately 2.2 mm (0.087 in.) and condition the compound according to Practice D3182.