ASTM D3191-10(2014)
(Test Method)Standard Test Methods for Carbon Black in SBR (Styrene-Butadiene Rubber)—Recipe and Evaluation Procedures
Standard Test Methods for Carbon Black in SBR (Styrene-Butadiene Rubber)—Recipe and Evaluation Procedures
SIGNIFICANCE AND USE
3.1 The major portion of carbon black consumed by the rubber industry is used to improve the physical properties, life expectancy, and utility of rubber products. These test methods provide an SBR recipe and directions for evaluating all types of carbon black intended for use in rubber products. Other procedures are available elsewhere in the ASTM standards for the evaluation of carbon black itself.
3.2 These test methods may be used to characterize carbon black in terms of specific properties of the standard compound. These test methods are useful for the quality assurance of carbon black production. They may also be used for the preparation of reference compounds, to confirm the day-to-day reliability of testing operations used in the rubber industry, for the evaluation of experimental compounds, and quality control of production compounds.
SCOPE
1.1 These test methods cover the standard materials, test formula, mixing procedure, and test methods for the evaluation and production control of carbon blacks in styrene butadiene rubber (SBR).
1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
1.3 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 appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D3191 − 10 (Reapproved 2014)
Standard Test Methods for
Carbon Black in SBR (Styrene-Butadiene Rubber)—Recipe
and Evaluation Procedures
This standard is issued under the fixed designation D3191; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D2084 Test Method for Rubber Property—Vulcanization
Using Oscillating Disk Cure Meter
1.1 These test methods cover the standard materials, test
D3182 PracticeforRubber—Materials,Equipment,andPro-
formula, mixing procedure, and test methods for the evaluation
cedures for Mixing Standard Compounds and Preparing
and production control of carbon blacks in styrene butadiene
Standard Vulcanized Sheets
rubber (SBR).
D3674 Test Method for Carbon Black—Relative Extrusion
1.2 The values stated in SI units are to be regarded as the 3
Mass (Withdrawn 1999)
standard. The values in parentheses are for information only.
D4483 Practice for Evaluating Precision for Test Method
1.3 This standard does not purport to address all of the
Standards in the Rubber and Carbon Black Manufacturing
safety concerns, if any, associated with its use. It is the Industries
responsibility of the user of this standard to establish appro-
D5289 Test Method for Rubber Property—Vulcanization
priate safety and health practices and determine the applica- Using Rotorless Cure Meters
bility of regulatory limitations prior to use.
E145 Specification for Gravity-Convection and Forced-
Ventilation Ovens
2. Referenced Documents
3. Significance and Use
2.1 ASTM Standards:
D412 Test Methods forVulcanized Rubber andThermoplas- 3.1 The major portion of carbon black consumed by the
tic Elastomers—Tension
rubber industry is used to improve the physical properties, life
D1646 Test Methods for Rubber—Viscosity, Stress expectancy, and utility of rubber products. These test methods
Relaxation, and Pre-Vulcanization Characteristics provideanSBRrecipeanddirectionsforevaluatingalltypesof
(Mooney Viscometer) carbon black intended for use in rubber products. Other
D1799 Practice for Carbon Black—Sampling Packaged procedures are available elsewhere in theASTM standards for
Shipments the evaluation of carbon black itself.
D1900 Practice for Carbon Black—Sampling Bulk Ship-
3.2 These test methods may be used to characterize carbon
ments
black in terms of specific properties of the standard compound.
These test methods are useful for the quality assurance of
carbon black production. They may also be used for the
These test methods are under the jurisdiction of ASTM Committee D24 on
Carbon Black and are the direct responsibility of Subcommittee D24.71 on Carbon
preparation of reference compounds, to confirm the day-to-day
Black Testing in Rubber.
reliability of testing operations used in the rubber industry, for
Current edition approved Sept. 1, 2014. Published November 2014. Originally
the evaluation of experimental compounds, and quality control
approved in 1973. Last previous edition approved in 2010 as D3191 – 10. DOI:
10.1520/D3191-10R14. of production compounds.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3191 − 10 (2014)
4. Standard Test Formula
Duration, Accumulative,
min min
4.1 Standard Formula:
Set the mill opening at 1.1 mm (0.045 in.) 2.0 2.0
A
Material IRM Quantity,
and band the polymer on the front roll.
No.
parts by
3 1
Make ⁄4 cuts every ⁄2 min from alternate
mass
sides.
SBR-1500 . 100.00
Add the sulfur slowly and evenly across 2.0 4.0
B,C
Zinc oxide 91 3.00
the mill at a uniform rate.
B,C
Sulfur 31 1.75
B,C
Stearic acid 21 1.00
Add the stearic acid. Make one ⁄4 cut 2.0 6.0
Carbon black . 50.00
from each side after the stearic acid has
C,D
TBBS . 1.00
been incorporated.
Total 156.75
E
Batch factor:
Add the carbon black evenly across the 10.0 16.0
mill at a uniform rate. When one half the
A
IRM 91 is available from G. H. Chemicals, Ltd., 1550 Brouillette St., P.O. Box
black is incorporated, open the mill to 1.4
456, St. Hyacinthe Quebec Canada, J2S 7B8. IRM 21 and IRM 31 are available 3
mm (0.055 in.) and make one ⁄4 cut from
from Akron Rubber Development Lab, 2887 Gilchrist Road, Akron, OH 44305.
each side. Add the remainder of the
B
FortheMIMprocedure,itisrecommendedthatablendofcompoundingmaterials
carbon black. When all the black has
bepreparedtoimproveaccuracyoftheweighingofthesematerials.Thismaterial
been incorporated, open the mill to 1.8
blendispreparedbyblendingaproportionalmassofeachmaterialinadrypowder 3
mm (0.070 in.) and make one ⁄4 cut from
blender such as a biconical blender or vee blender. A mortar and pestle may be
each side.
used for blending small quantities.
C
Formillmixes,weightherubberandcarbonblacktothenearest1.0g,thesulfur
Note—Do not cut any stock while free
and the accelerator to the nearest 0.02 g, and all of the other compounding
carbon black is evident in the bank or on
materialstothenearest0.1g.ForMIMmixes,weightherubberandmaterialblend
the milling surface. Be certain to return
to the nearest 0.01 g and individual pigments, if used, to the nearest 0.001 g.
any pigments that drop through the mill to
D
TBBS is N-tert-butyl-w-benzothiazolesulfenamide.
the milling stock.
E
Forthemillmixes,abatchfactorshouldbeselectedtothenearest0.5togiveas
largeatotalmassaspossiblethatwillnotexceed525.0g.Calculateallpartstothe
Add the zinc oxide and TBBS at the 3.0 19.0
nearest0.01part.ForMIMmixes,calculateabatchfactortothenearest0.01that
1.8-mm (0.070-in.) setting.
will provide a 75 % loading of the mixing chamber.
Make three ⁄4 cuts from each side and 2.0 21.0
cut the stock from the mill.
5. Sampling and Sample Preparation
Set the rolls at 0.8 mm (0.032 in.). Pass 2.0 23.0
5.1 Samples shall be taken in accordance with Practice
the rolled stock endwise through the mill
D1799 or Practice D1900.
six times.
5.2 The carbon black shall be conditioned before weighing
Open the mill to give a minimum stock 1.0 24.0
thickness of 6 mm (0.25 in.) and pass the
and mixing by heating in a Type 1B oven, as described in
stock through the rolls four times, folding
Specification E145,for1hat125 6 3°C. The black shall be
it back on itself each time.
placed in an open vessel of suitable dimensions so that the
Total Time 24.0
depthofblackisnomorethan10mmduringconditioning.The
6.2.1.1 Sheet off the stock from the mill at a setting to give
blackconditionedasaboveshallbestoredinaclosedmoisture-
a finished gauge of approximately 2.2 mm (0.085 in.). Cool on
proof container until ready for mixing.
a flat dry metal surface.
6.2.1.2 To prevent absorption of moisture, condition the
6. Mixing Procedure
sheeted stock for 1 to8hata temperature of 23 6 3°C in a
closed container after cooling unless the relative humidity is
6.1 For general mixing procedure refer to Practice D3182.
controlled at 35 6 5 % in accordance with Practice D3182.
6.1.1 Mixing shall be done with the mill roll temperature
6.2.2 Test Method B—Internal Mixer:
maintained at 50 6 5°C. The indicated mill openings are
6.2.2.1 BR Banbury: Water cooled (not over 16°C) rotors at
approximate and should be adjusted to maintain a good
8.06 rad/s (77 r/min). Start loading when Banbury temperature
working bank at the nip of the rolls. The following three
recorder indicates 32°C.
mixing procedures are offered:
6.2.2.2 Before mixing the first batch, adjust the internal
(1)Test Method A—Mill Mix,
mixer temperature to achieve the discharge conditions outlined
(2)Test Method B—Internal Mixer, and
in the table below. Close the gate.
(3)Test Method C—Miniature Internal Mixer.
Duration, Accumulative,
6.1.1.1 Check and record the stock mass. If it differs from
min min
thetheoreticalvaluebymorethan0.5 %,rejectthebatch.From
Raise ram, add SBR-1500 and zinc 0.75 0.75
this stock, cut enough sample to allow testing of compound
oxide, and lower ram.
viscosity in accordance with Test Methods D1646, and curing
characteristicsinaccordancewithTestMethodD2084,orboth, Raise ram, add all other ingredients
except TBBS, and lower ram.
and extrudability of unvulcanized compounds in accordance
with Test Method D3674, if these are desired.
Raise ram, sweep, lower ram. 1.25 2.0
6.2 Mixing Cycle:
Dump at 3.5 min but not over 71°C. 1.5 3.5
Total Time 3.5
6.2.1 Test Method A—Mill Mix:
D3191 − 10 (2014)
6.2.2.3 Mill in accordance with Practice D3182, 6-by-12 in. 6.2.3.4 Check the batch mass and record. Reject the batch if
mill with water cooling. (Before using the mill warm up with more than 60.5 % differ from the theoretical mass.
a batch of rubber. Start mill operations when roll surface 6.2.3.5 For testing of stress-strain, pass the batch through
temperature is 32°C.) the mill to produce a stock thickness of 2.2 mm (0.085 in.).
6.2.3.6 For testing of curing characteristics in accordance
6.2.2.4 Sheet out on the mill, weigh, and check batch mass.
with Test Method D2084, pass the batch through the mill to
Discard if more than 0.5 % different from theoretical mass.
produce a minimum stock thickness of 6 mm (0.25 in.).
Duration, Accumulative,
min min 6.2.3.7 To prevent absorption of moisture, condition the
sheeted stock for 1 to8hata temperature of 23 6 3°C in a
Return to mill, set at 1.8 mm (0.070 in.) 2.5 2.5
closed container after cooling unless the relative humidity is
between rolls, band on mill, add TBBS, and
make five ⁄4 cuts from each side. controlled at 35 6 5 % in accordance with Practice D3182.
Total Time 2.5
Vulcanize and test in accordance with Section 7.
6.2.2.5 Remove stock from the mill in a sheet and allow to
7. Preparation and Testing of Vulcanizates
rest1hona flat, dry metal surface.
6.2.2.6 Weigh 650 g, roll, and pass endwise nine times, 7.1 For stress-strain testing, prepare test slabs and vulcanize
them in accordance with Practice D3182.
without banding through the mill set at 0.5 mm (0.020 in.)
between rolls. Start with a surface temperature of 32°C. 7.1.1 The recommended standard cure is 50 min at 145°C.
7.1.2 Conditionvulcanizatesofcompoundsatatemperature
6.2.2.7 Sheet out stock to a thickness of about 2.2 mm
of 23 6 2°C (73 6 3.6°F) for at least 16 h and for not more
(0.085 in.) and cool on a flat, dry metal surface.
than 96 h before preparing and testing, unless otherwise
6.2.2.8 Unless otherwise specified, condition the sheeted
specified.
compoundfor1to24hat23 63°C(73.4 65.4°F)atarelative
humidity not greater than 55 %. For maximum precision,
NOTE 1—Quality control of rubber production may require testing
condition for 1 to 24 h in a closed container to prevent within 1 to6hto provide close surveillance of the plant operation;
however, slightly different results may be obtained.
absorption of moisture from the air, or in an area controlled at
35 6 5 % relative humidity in accordance with Practice
7.1.3 PreparethetestspecimensinaccordancewithPractice
D3182. Vulcanize and test in accordance with Section 7.
D3182, and obtain modulus, tensile, and elongation parameters
in accordance with Test Methods D412. Typically, a test
6.2.3 Test Method C—Miniature Internal Mixer:
specimen is prepared using the current Industry Reference
6.2.3.1 Prepare the rubber by passing it through a mill one
Black, for example IRB 7, with each set of mixes and the data
time with the mill temperature at 50 6 5°C and a mill opening
obtained is reported as a difference from the IRB.
at 0.51 mm (0.020 in.).
Duration, Accumulative, 7.2 An alternative to measuring stress-strain properties of
min min
vulcanizates is the cure-meter measurement of vulcanization
parameters with an Oscillating Disk cure meter in accordance
With the head temperature of the 1.0 1.0
miniature internal mixer maintained at 60
with Test Method D2084 or a Rotorless Cure Meter Test in
± 3°C and the unloaded slow rotor speed
accordance with Test Method D5289.
at 6.3 to 6.6 rad/s (60 to 63 r/min), feed
7.2.1 The recommended standard Oscillating Disk test con-
the rubber into the mixing chamber and
start the timer as soon as all the rubber is
ditions are: 1.7 Hz oscillation frequency, 61° amplitude of
added. Break down the rubber. While the
oscillation, 160°C die temperature, 30-min test time, and no
rubber is breaking down, set the powder
preheating. The recommended test conditions for the Rotorless
chute in place.
Cure Meter are: 1.7 Hz oscillation frequency, 60.5° of arc for
Add the sulfur, zinc oxide, stearic acid, 1.0 2.0
torsional shear cure meters, 6 0.05 mm for linear shear cure
and TBBS followed by the carbon black.
meters, 160°C die temperature, 30-min test time, and no
Quickly insert the ram in the chute and
place a 1-kg mass on the ram.
preheating. Tolerances for the listed conditions are included in
the specified test methods.
When the ram positon indicates that the 1.0 3.0
7.2.2 The recommended standard test parameters are M ,
carbon black has been added, remove the
L
chute and sweep the remaining carbon
M ,t ,t' (50), and t' (90).
H s1 c c
black from the ram and chute cavity into
the mixing chamber.
8. Precision and Bias
Allow the compound to mix. 6.0 9.0
8.1 This precision and bias statement has been prepared in
Total time 9.0
accordance with Practice D4483. Refer to Practice D4483 for
6.2.3.2 Turn off the motor, raise the ram, remove the mixing
terminology and other statistical details.
chamber,andunloadthebatch.Recordthebatchtemperatureif
8.2 Precision—The precision results in this precision and
desired.
bias section give an estimate of the precision of this test
6.2.3.3 With the mill at room temperature, pass the batch
methodwiththematerials(rubbers,carbonblacks,etc.)usedin
through the mill set at 0.80 mm (0.032 in.). Fold it on itself and
feed it back through the mill five more times, always keeping
the grain in the same direction and folding it on itself each
Supporting data have been filed at ASTM International Headquarters and may
time. be obtained by requesting Research Report RR:D24-1030.
D3191 − 10 (2014)
the particular interlaboratory program described in 8.3 through have come from different sample populations. Such a decision
8.4.2.3. The precision parameters should not be used for dictates that some appropriate action be
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D3191 − 10 D3191 − 10 (Reapproved 2014)
Standard Test Methods for
Carbon Black in SBR (Styrene-Butadiene Rubber)—Recipe
and Evaluation Procedures
This standard is issued under the fixed designation D3191; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 These test methods cover the standard materials, test formula, mixing procedure, and test methods for the evaluation and
production control of carbon blacks in styrene butadiene rubber (SBR).
1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
1.3 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 appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D412 Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension
D1646 Test Methods for Rubber—Viscosity, Stress Relaxation, and Pre-Vulcanization Characteristics (Mooney Viscometer)
D1799 Practice for Carbon Black—Sampling Packaged Shipments
D1900 Practice for Carbon Black—Sampling Bulk Shipments
D2084 Test Method for Rubber Property—Vulcanization Using Oscillating Disk Cure Meter
D3182 Practice for Rubber—Materials, Equipment, and Procedures for Mixing Standard Compounds and Preparing Standard
Vulcanized Sheets
D3674 Test Method for Carbon Black—Relative Extrusion Mass (Withdrawn 1999)
D4483 Practice for Evaluating Precision for Test Method Standards in the Rubber and Carbon Black Manufacturing Industries
D5289 Test Method for Rubber Property—Vulcanization Using Rotorless Cure Meters
E145 Specification for Gravity-Convection and Forced-Ventilation Ovens
3. Significance and Use
3.1 The major portion of carbon black consumed by the rubber industry is used to improve the physical properties, life
expectancy, and utility of rubber products. These test methods provide an SBR recipe and directions for evaluating all types of
carbon black intended for use in rubber products. Other procedures are available elsewhere in the ASTM standards for the
evaluation of carbon black itself.
3.2 These test methods may be used to characterize carbon black in terms of specific properties of the standard compound. These
test methods are useful for the quality assurance of carbon black production. They may also be used for the preparation of reference
compounds, to confirm the day-to-day reliability of testing operations used in the rubber industry, for the evaluation of
experimental compounds, and quality control of production compounds.
These test methods are under the jurisdiction of ASTM Committee D24 on Carbon Black and are the direct responsibility of Subcommittee D24.71 on Carbon Black
Testing in Rubber.
Current edition approved Jan. 1, 2010Sept. 1, 2014. Published February 2010November 2014. Originally approved in 1973. Last previous edition approved in 20092010
ε1
as D3191 – 09D3191 – 10. . DOI: 10.1520/D3191-10.10.1520/D3191-10R14.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3191 − 10 (2014)
4. Standard Test Formula
4.1 Standard Formula:
A
Material IRM Quantity,
No.
parts by
mass
SBR-1500 . 100.00
B,C
Zinc oxide 91 3.00
B,C
Sulfur 31 1.75
B,C
Stearic acid 21 1.00
Carbon black . 50.00
C,D
TBBS . 1.00
Total 156.75
E
Batch factor:
A
IRM 91 is available from G. H. Chemicals, Ltd., 1550 Brouillette St., P.O. Box 456, St. Hyacinthe Quebec Canada, J2S 7B8. IRM 21 and IRM 31 are available from Akron
Rubber Development Lab, 2887 Gilchrist Road, Akron, OH 44305.
B
For the MIM procedure, it is recommended that a blend of compounding materials be prepared to improve accuracy of the weighing of these materials. This material blend
is prepared by blending a proportional mass of each material in a dry powder blender such as a biconical blender or vee blender. A mortar and pestle may be used for
blending small quantities.
C
For mill mixes, weigh the rubber and carbon black to the nearest 1.0 g, the sulfur and the accelerator to the nearest 0.02 g, and all of the other compounding materials
to the nearest 0.1 g. For MIM mixes, weigh the rubber and material blend to the nearest 0.01 g and individual pigments, if used, to the nearest 0.001 g.
D
TBBS is N-tert-butyl-w-benzothiazolesulfenamide.
E
For the mill mixes, a batch factor should be selected to the nearest 0.5 to give as large a total mass as possible that will not exceed 525.0 g. Calculate all parts to the
nearest 0.01 part. For MIM mixes, calculate a batch factor to the nearest 0.01 that will provide a 75 % loading of the mixing chamber.
5. Sampling and Sample Preparation
5.1 Samples shall be taken in accordance with Practice D1799 or Practice D1900.
5.2 The carbon black shall be conditioned before weighing and mixing by heating in a Type 1B oven, as described in
Specification E145, for 1 h at 125 6 3°C. The black shall be placed in an open vessel of suitable dimensions so that the depth of
black is no more than 10 mm during conditioning. The black conditioned as above shall be stored in a closed moisture-proof
container until ready for mixing.
6. Mixing Procedure
6.1 For general mixing procedure refer to Practice D3182.
6.1.1 Mixing shall be done with the mill roll temperature maintained at 50 6 5°C. The indicated mill openings are approximate
and should be adjusted to maintain a good working bank at the nip of the rolls. The following three mixing procedures are offered:
(1) Test Method A—Mill Mix,
(2) Test Method B—Internal Mixer, and
(3) Test Method C—Miniature Internal Mixer.
6.1.1.1 Check and record the stock mass. If it differs from the theoretical value by more than 0.5 %, reject the batch. From this
stock, cut enough sample to allow testing of compound viscosity in accordance with Test Methods D1646, and curing
characteristics in accordance with Test Method D2084, or both, and extrudability of unvulcanized compounds in accordance with
Test Method D3674, if these are desired.
6.2 Mixing Cycle:
6.2.1 Test Method A—Mill Mix:
D3191 − 10 (2014)
Duration, Accumulative,
min min
Set the mill opening at 1.1 mm (0.045 in.) 2.0 2.0
and band the polymer on the front roll.
3 1
Make ⁄4 cuts every ⁄2 min from alternate
sides.
Add the sulfur slowly and evenly across 2.0 4.0
the mill at a uniform rate.
Add the stearic acid. Make one ⁄4 cut 2.0 6.0
from each side after the stearic acid has
been incorporated.
Add the carbon black evenly across the 10.0 16.0
mill at a uniform rate. When one half the
black is incorporated, open the mill to 1.4
mm (0.055 in.) and make one ⁄4 cut from
each side. Add the remainder of the
carbon black. When all the black has
been incorporated, open the mill to 1.8
mm (0.070 in.) and make one ⁄4 cut from
each side.
Note—Do not cut any stock while free
carbon black is evident in the bank or on
the milling surface. Be certain to return
any pigments that drop through the mill to
the milling stock.
Add the zinc oxide and TBBS at the 3.0 19.0
1.8-mm (0.070-in.) setting.
Make three ⁄4 cuts from each side and 2.0 21.0
cut the stock from the mill.
Set the rolls at 0.8 mm (0.032 in.). Pass 2.0 23.0
the rolled stock endwise through the mill
six times.
Open the mill to give a minimum stock 1.0 24.0
thickness of 6 mm (0.25 in.) and pass the
stock through the rolls four times, folding
it back on itself each time.
Total Time 24.0
6.2.1.1 Sheet off the stock from the mill at a setting to give a finished gauge of approximately 2.2 mm (0.085 in.). Cool on a
flat dry metal surface.
6.2.1.2 To prevent absorption of moisture, condition the sheeted stock for 1 to 8 h at a temperature of 23 6 3°C in a closed
container after cooling unless the relative humidity is controlled at 35 6 5 % in accordance with Practice D3182.
6.2.2 Test Method B—Internal Mixer:
6.2.2.1 BR Banbury: Water cooled (not over 16°C) rotors at 8.06 rad/s (77 r/min). Start loading when Banbury temperature
recorder indicates 32°C.
6.2.2.2 Before mixing the first batch, adjust the internal mixer temperature to achieve the discharge conditions outlined in the
table below. Close the gate.
Duration, Accumulative,
min min
Raise ram, add SBR-1500 and zinc 0.75 0.75
oxide, and lower ram.
Raise ram, add all other ingredients
except TBBS, and lower ram.
D3191 − 10 (2014)
Raise ram, sweep, lower ram. 1.25 2.0
Dump at 3.5 min but not over 71°C. 1.5 3.5
Total Time 3.5
6.2.2.3 Mill in accordance with Practice D3182, 6-by-12 in. mill with water cooling. (Before using the mill warm up with a
batch of rubber. Start mill operations when roll surface temperature is 32°C.)
6.2.2.4 Sheet out on the mill, weigh, and check batch mass. Discard if more than 0.5 % different from theoretical mass.
Duration, Accumulative,
min min
Return to mill, set at 1.8 mm (0.070 in.) 2.5 2.5
between rolls, band on mill, add TBBS, and
make five ⁄4 cuts from each side.
Total Time 2.5
6.2.2.5 Remove stock from the mill in a sheet and allow to rest 1 h on a flat, dry metal surface.
6.2.2.6 Weigh 650 g, roll, and pass endwise nine times, without banding through the mill set at 0.5 mm (0.020 in.) between rolls.
Start with a surface temperature of 32°C.
6.2.2.7 Sheet out stock to a thickness of about 2.2 mm (0.085 in.) and cool on a flat, dry metal surface.
6.2.2.8 Unless otherwise specified, condition the sheeted compound for 1 to 24 h at 23 6 3°C (73.4 6 5.4°F) at a relative
humidity not greater than 55 %. For maximum precision, condition for 1 to 24 h in a closed container to prevent absorption of
moisture from the air, or in an area controlled at 35 6 5 % relative humidity in accordance with Practice D3182. Vulcanize and
test in accordance with Section 7.
6.2.3 Test Method C—Miniature Internal Mixer:
6.2.3.1 Prepare the rubber by passing it through a mill one time with the mill temperature at 50 6 5°C and a mill opening at
0.51 mm (0.020 in.).
Duration, Accumulative,
min min
With the head temperature of the 1.0 1.0
miniature internal mixer maintained at 60
± 3°C and the unloaded slow rotor speed
at 6.3 to 6.6 rad/s (60 to 63 r/min), feed
the rubber into the mixing chamber and
start the timer as soon as all the rubber is
added. Break down the rubber. While the
rubber is breaking down, set the powder
chute in place.
Add the sulfur, zinc oxide, stearic acid, 1.0 2.0
and TBBS followed by the carbon black.
Quickly insert the ram in the chute and
place a 1-kg mass on the ram.
When the ram positon indicates that the 1.0 3.0
carbon black has been added, remove the
chute and sweep the remaining carbon
black from the ram and chute cavity into
the mixing chamber.
Allow the compound to mix. 6.0 9.0
Total time 9.0
6.2.3.2 Turn off the motor, raise the ram, remove the mixing chamber, and unload the batch. Record the batch temperature if
desired.
6.2.3.3 With the mill at room temperature, pass the batch through the mill set at 0.80 mm (0.032 in.). Fold it on itself and feed
it back through the mill five more times, always keeping the grain in the same direction and folding it on itself each time.
6.2.3.4 Check the batch mass and record. Reject the batch if more than 60.5 % differ from the theoretical mass.
6.2.3.5 For testing of stress-strain, pass the batch through the mill to produce a stock thickness of 2.2 mm (0.085 in.).
6.2.3.6 For testing of curing characteristics in accordance with Test Method D2084, pass the batch through the mill to produce
a minimum stock thickness of 6 mm (0.25 in.).
6.2.3.7 To prevent absorption of moisture, condition the sheeted stock for 1 to 8 h at a temperature of 23 6 3°C in a closed
container after cooling unless the relative humidity is controlled at 35 6 5 % in accordance with Practice D3182. Vulcanize and
test in accordance with Section 7.
7. Preparation and Testing of Vulcanizates
7.1 For stress-strain testing, prepare test slabs and vulcanize them in accordance with Practice D3182.
7.1.1 The recommended standard cure is 50 min at 145°C.
D3191 − 10 (2014)
7.1.2 Condition vulcanizates of compounds at a temperature of 23 6 2°C (73 6 3.6°F) for at least 16 h and for not more than
96 h before preparing and testing, unless otherwise specified.
NOTE 1—Quality control of rubber production may require testing within 1 to 6 h to provide close surveillance of the plant operation; however, slightly
different results may be obtained.
7.1.3 Prepare the test specimens in accordance with Practice D3182, and obtain modulus, tensile, and elongation parameters in
accordance with Test Methods D412. Typically, a test specimen is prepared using the current Industry Reference Black, for
example IRB 7, with each set of mixes and the data obtained is reported as a difference from the IRB.
7.2 An alternative to measuring stress-strain properties of vulcanizates is the cure-meter measurement of vulcanization
parameters with an Oscillating Disk cure meter in accordance with Test Method D2084 or a Rotorless Cure Meter Test in
accordance with Test Method D5289.
7.2.1 The recommended standard Oscillating Disk test conditions are: 1.7 Hz oscillation frequency, 61° amplitude of
oscillation, 160°C die temperature, 30-min test time, and no preheating. The recommended test conditions for the Rotorless Cure
Meter are: 1.7 Hz oscillation frequency, 60.5° of arc for torsional shear cure meters, 6 0.05 mm for linear shear cure meters,
160°C die temperature, 30-min test time, and no preheating. Tolerances for the listed conditions are included in the specified test
methods.
7.2.2 The recommended standard test parameters are M , M , t , t' (50), and t' (90).
L H s1 c c
8. Precision and Bias
8.1 This precision and bias statement has bee
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