ASTM D3493-21

Standard Test Method for Carbon Black—Oil Absorption Number of Compressed Sample (COAN)

SIGNIFICANCE AND USE
4.1 The oil absorption number of a carbon black is related to the processing and vulcanizate properties of rubber compounds containing the carbon black.  
4.2 The difference between the regular oil absorption number and the oil absorption number of compressed sample is some measure of the stability of the structure of the carbon black.
SCOPE
1.1 This test method covers the procedure for the mechanical compression of a carbon black sample and the determination of the oil absorption number of the compressed sample.  
1.2 The values stated in SI units are to be regarded as the standard. The values given 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-May-2021
• ICS: 83.040.20 - Rubber compounding ingredients
• Technical Committee: D24 - Carbon Black
• Drafting Committee: D24.11 - Carbon Black Structure

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D3493 − 21
Standard Test Method for
Carbon Black—Oil Absorption Number of Compressed
1
Sample (COAN)
This standard is issued under the fixed designation D3493; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope StandardsintheRubberandCarbonBlackManufacturing
Industries
1.1 This test method covers the procedure for the mechani-
cal compression of a carbon black sample and the determina-
3. Summary of Test Method
tion of the oil absorption number of the compressed sample.
3.1 Asample of carbon black is compressed four times in a
1.2 The values stated in SI units are to be regarded as the
compression cylinder at a pressure of 165 MPa (24000 psi)
standard. The values given in parentheses are for information
and then tested in an absorptometer to determine the oil
only.
absorption number.
1.3 This standard does not purport to address all of the
3.2 n-Dibutyl phthalate, paraffin oil, or EFAoil is added by
safety concerns, if any, associated with its use. It is the
means of a constant-rate buret to the compressed sample of
responsibility of the user of this standard to establish appro-
carbonblackinthemixerchamberofanabsorptometer.Asthe
priate safety, health, and environmental practices and deter-
sample absorbs the oil, the mixture changes from a free-
mine the applicability of regulatory limitations prior to use.
flowing state to one of a semiplastic agglomeration, with an
1.4 This international standard was developed in accor-
accompanying increase in viscosity.This increased viscosity is
dance with internationally recognized principles on standard-
transmitted to the torque-sensing system of the absorptometer.
ization established in the Decision on Principles for the
When the viscosity of the mixture reaches a predetermined
Development of International Standards, Guides and Recom-
torque level, the absorptometer and buret will simultaneously
mendations issued by the World Trade Organization Technical
shut off. The volume of oil added is read from the direct
Barriers to Trade (TBT) Committee.
reading buret.The volume of oil per unit mass of carbon black
is the oil absorption number. Either DBP, paraffin oil, or EFA
2. Referenced Documents
oil is acceptable for use with many standard pelleted grades of
2
2.1 ASTM Standards:
N-series carbon blacks found in Classification D1765. COAN
D1765Classification System for Carbon Blacks Used in
testing using paraffin oil or EFA oil on some specialty blacks
Rubber Products
and powder blacks may result in significant differences when
D1799 Practice for Carbon Black—Sampling Packaged
compared to COAN testing using DBP oil. Referee testing
Shipments
betweensuppliersandusersshoulduseDBPoiluntilsuchtime
D1900Practice for Carbon Black—Sampling Bulk Ship-
that precision data is available for paraffin and EFA oils.
ments
4. Significance and Use
D2414Test Method for Carbon Black—Oil Absorption
Number (OAN)
4.1 Theoilabsorptionnumberofacarbonblackisrelatedto
D4821Guide for Carbon Black—Validation of Test Method
theprocessingandvulcanizatepropertiesofrubbercompounds
Precision and Bias
containing the carbon black.
D4483Practice for Evaluating Precision for Test Method
4.2 The difference between the regular oil absorption num-
ber and the oil absorption number of compressed sample is
1
some measure of the stability of the structure of the carbon
This test method is under the jurisdiction ofASTM Committee D24 on Carbon
Black and is the direct responsibility of Subcommittee D24.11 on Carbon Black
black.
Structure.
3
CurrenteditionapprovedJune1,2021.PublishedJuly2021.Originallyapproved
5. Apparatus
in 1976. Last previous edition approved in 2020 as D3493–20. DOI: 10.1520/
D3493-21.
5.1 Balance, analytical, 0.01-g sensitivity.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3
Standards volume information, refer to the standard’s Document Summary page on Each apparatus is to be operated and maintained in accordance with the
the ASTM website. manufacturer’s directions for optimum performance.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D3493 − 21
5.2 Oven, gravity-convection type, capable of maintaining 8. Calibration and Standardization
125°C 6 5°C.
8.1 See Test Method D2414.
5.3 Carbon Bl
...

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: D3493 − 20 D3493 − 21
Standard Test Method for
Carbon Black—Oil Absorption Number of Compressed
1
Sample (COAN)
This standard is issued under the fixed designation D3493; 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 This test method covers the procedure for the mechanical compression of a carbon black sample and the determination of the
oil absorption number of the compressed sample.
1.2 The values stated in SI units are to be regarded as the standard. The values given 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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
D1765 Classification System for Carbon Blacks Used in Rubber Products
D1799 Practice for Carbon Black—Sampling Packaged Shipments
D1900 Practice for Carbon Black—Sampling Bulk Shipments
D2414 Test Method for Carbon Black—Oil Absorption Number (OAN)
D4821 Guide for Carbon Black—Validation of Test Method Precision and Bias
D4483 Practice for Evaluating Precision for Test Method Standards in the Rubber and Carbon Black Manufacturing Industries
3. Summary of Test Method
3.1 A sample of carbon black is compressed four times in a compression cylinder at a pressure of 165 MPa (24 000 psi) and then
tested in an absorptometer to determine the oil absorption number.
3.2 n-Dibutyl phthalate, paraffin oil, or EFA oil is added by means of a constant-rate buret to the compressed sample of carbon
black in the mixer chamber of an absorptometer. As the sample absorbs the oil, the mixture changes from a free-flowing state to
one of a semiplastic agglomeration, with an accompanying increase in viscosity. This increased viscosity is transmitted to the
torque-sensing system of the absorptometer. When the viscosity of the mixture reaches a predetermined torque level, the
1
This test method is under the jurisdiction of ASTM Committee D24 on Carbon Black and is the direct responsibility of Subcommittee D24.11 on Carbon Black Structure.
Current edition approved Dec. 1, 2020June 1, 2021. Published January 2021July 2021. Originally approved in 1976. Last previous edition approved in 20192020 as
D3493 – 19a.D3493 – 20. DOI: 10.1520/D3493-20.10.1520/D3493-21.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D3493 − 21
absorptometer and buret will simultaneously shut off. The volume of oil added is read from the direct reading buret. The volume
of oil per unit mass of carbon black is the oil absorption number. Either DBP, paraffin oil, or EFA oil is acceptable for use with
many standard pelleted grades of N-series carbon blacks found in Classification D1765. COAN testing using paraffin oil or EFA
oil on some specialty blacks and powder blacks may result in significant differences when compared to COAN testing using DBP
oil. Referee testing between suppliers and users should use DBP oil until such time that precision data is available for paraffin and
EFA oils.
4. Significance and Use
4.1 The oil absorption number of a carbon black is related to the processing and vulcanizate properties of rubber compounds
containing the carbon black.
4.2 The difference between the regular oil absorption number and the oil absorption number of compressed sample is some
measure of the stability of the structure of the carbon black.
3
5. Apparatus
5.1 Balance, analytical, 0.01-g sensitivity.
5.2 Oven, gravity-convection t
...