ASTM D4018-23

Standard Test Methods for Properties of Continuous Filament Carbon and Graphite Fiber Tows

SIGNIFICANCE AND USE
5.1 The properties determined by these test methods are of value in material specifications, qualifications, data base generation, certification, research, and development.  
5.2 These test methods are intended for the testing of fibers that have been specifically developed for use as reinforcing agents in advanced composite structures. The test results of an impregnated and consolidated fiber should be representative of the strength and modulus that are available in the material when used as intended. The performance of fibers in different resin systems can vary significantly so that correlations between results using these test methods and composite testing may not always be obtained.  
5.3 The reproducibility of test results is dependent upon precise control over all test conditions. Resin type, content and distribution, curing process, filament alignment, gripping in the testing machine, and alignment in the testing machine are of special importance.  
5.4 The measured strengths of fibers are not unique quantities and test results are strongly dependent on the test methods used. Therefore the test method described here will not necessarily give the same mean strengths or standard deviations as those obtained from single filaments, dry fibers, composite laminas, or composite laminates.
SCOPE
1.1 These test methods cover the preparation and tensile testing of resin-impregnated and consolidated test specimens made from continuous filament carbon and graphite yarns, rovings, and tows to determine their tensile properties.  
1.2 These test methods also cover the determination of the density and mass per unit length of the yarn, roving, or tow to provide supplementary data for tensile property calculation.  
1.3 These test methods include a procedure for sizing removal to provide the preferred desized fiber samples for density measurement. This procedure may also be used to determine the weight percent sizing.  
1.4 These test methods include a procedure for determining the weight percent moisture adsorption of carbon or graphite fiber.  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.6 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.  
1.7 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-Aug-2023
• ICS: 59.100.20 - Carbon materials
• Technical Committee: D30 - Composite Materials
• Drafting Committee: D30.03 - Constituent/Precursor Properties

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: D4018 − 23
Standard Test Methods for
Properties of Continuous Filament Carbon and Graphite
1
Fiber Tows
This standard is issued under the fixed designation D4018; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 2. Referenced Documents
2
1.1 These test methods cover the preparation and tensile 2.1 ASTM Standards:
testing of resin-impregnated and consolidated test specimens D70 Test Method for Specific Gravity and Density of Semi-
made from continuous filament carbon and graphite yarns, Solid Asphalt Binder (Pycnometer Method)
rovings, and tows to determine their tensile properties. D1193 Specification for Reagent Water
D3800 Test Method for Density of High-Modulus Fibers
1.2 These test methods also cover the determination of the
D5550 Test Method for Specific Gravity of Soil Solids by
density and mass per unit length of the yarn, roving, or tow to
Gas Pycnometer
provide supplementary data for tensile property calculation.
E4 Practices for Force Calibration and Verification of Test-
1.3 These test methods include a procedure for sizing
ing Machines
removal to provide the preferred desized fiber samples for
E83 Practice for Verification and Classification of Exten-
density measurement. This procedure may also be used to
someter Systems
determine the weight percent sizing.
2.2 Other Document:
3
CRC Handbook of Chemistry and Physics
1.4 These test methods include a procedure for determining
the weight percent moisture adsorption of carbon or graphite
3. Terminology
fiber.
3.1 Definitions:
1.5 The values stated in SI units are to be regarded as
3.1.1 sizing, n—a generic term for compounds which, when
standard. No other units of measurement are included in this
applied to yarn or fabric, form a more or less continuous solid
standard.
film around the yarn and individual fibers.
1.6 This standard does not purport to address all of the
3.2 Definitions of Terms Specific to This Standard:
safety concerns, if any, associated with its use. It is the
3.2.1 desized fiber, n—fiber which has had a sizing removed
responsibility of the user of this standard to establish appro-
from it.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. 3.2.2 fiber, n—continuous filament carbon or graphite yarn,
1.7 This international standard was developed in accor- roving, or tow.
dance with internationally recognized principles on standard-
3.2.3 sized fiber, n—a fiber with a sizing applied to it.
ization established in the Decision on Principles for the
3.2.4 unsized fiber, n—fiber which has never had a sizing
Development of International Standards, Guides and Recom-
applied to it.
mendations issued by the World Trade Organization Technical
3.3 Symbols:
Barriers to Trade (TBT) Committee.
3.3.1 A—Unit conversion factor for tensile strength
1 2
These test methods are under the jurisdiction of ASTM Committee D30 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Composite Materials and are the direct responsibility of Subcommittee D30.03 on contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Constituent/Precursor Properties. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Sept. 1, 2023. Published September 2023. Originally the ASTM website.
3
approved in 1981. Last previous edition approved in 2017 as D4018 – 17. DOI: CRC Press Inc., Boca Raton, Ann Arbor, London, Tokyo, 73rd Edition,
10.1520/D4018-23. 1992–1993.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D4018 − 23
3.3.2 B—Unit conversion factor for tensile modulus agents in advanced composite structures. The test results of an
impregnated and consolidated fiber should be representative of
3.3.3 E—fiber chord modulus
the strength and modulus that are available in the material
3.3.4 ε —Lower strain limit
l
when used as intended. The performance of fibers in different
3.3.5 ε —Upper strain limit
u resin systems can vary significantly so that correlations be-
3.3.6 k —correction factor for density of sizing tween results using these test methods and composite testing
c
may not always be obtained.
3.3.7 L—specimen length
5.3 The reproducibility of
...

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: D4018 − 17 D4018 − 23
Standard Test Methods for
Properties of Continuous Filament Carbon and Graphite
1
Fiber Tows
This standard is issued under the fixed designation D4018; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 These test methods cover the preparation and tensile testing of resin-impregnated and consolidated test specimens made from
continuous filament carbon and graphite yarns, rovings, and tows to determine their tensile properties.
1.2 These test methods also cover the determination of the density and mass per unit length of the yarn, roving, or tow to provide
supplementary data for tensile property calculation.
1.3 These test methods include a procedure for sizing removal to provide the preferred desized fiber samples for density
measurement. This procedure may also be used to determine the weight percent sizing.
1.4 These test methods include a procedure for determining the weight percent moisture adsorption of carbon or graphite fiber.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 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 healthsafety, health, and environmental practices and determine
the applicability of regulatory limitations prior to use.
1.7 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:
D70 Test Method for Specific Gravity and Density of Semi-Solid Asphalt Binder (Pycnometer Method)
D1193 Specification for Reagent Water
D3800 Test Method for Density of High-Modulus Fibers
D5550 Test Method for Specific Gravity of Soil Solids by Gas Pycnometer
E4 Practices for Force Calibration and Verification of Testing Machines
1
These test methods are under the jurisdiction of ASTM Committee D30 on Composite Materials and are the direct responsibility of Subcommittee D30.03 on
Constituent/Precursor Properties.
Current edition approved Jan. 15, 2017Sept. 1, 2023. Published January 2017September 2023. Originally approved in 1981. Last previous edition approved in 20112017
as D4018 – 11.D4018 – 17. DOI: 10.1520/D4018-17.10.1520/D4018-23.
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 ----------------------
D4018 − 23
E83 Practice for Verification and Classification of Extensometer Systems
2.2 Other Document:
3
CRC Handbook of Chemistry and Physics
3. Terminology
3.1 Definitions:
3.1.1 sizing, n—a generic term for compounds which, when applied to yarn or fabric, form a more or less continuous solid film
around the yarn and individual fibers.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 desized fiber, n—fiber which has had a sizing removed from it.
3.2.2 fiber, n—continuous filament carbon or graphite yarn, roving, or tow.
3.2.3 sized fiber, n—a fiber with a sizing applied to it.
3.2.4 unsized fiber, n—fiber which has never had a sizing applied to it.
3.3 Symbols:
3.3.1 A—Unit conversion factor for tensile strength
3.3.2 B—Unit conversion factor for tensile modulus
3.3.3 E—fiber chord modulus
3.3.4 ε —Lower strain limit
l
3.3.5 ε —Upper strain limit
u
3.3.6 k —correction factor for density of sizesizing
c
3.3.7 L—specimen length
3.3.8 MUL—the mass per unit length of the sized fiber
3.3.9 MUL —the mass per unit length of the impregnated and consolidated fiber
I
3.3.10 P—maximum load
3.3.11 P —tensile load at lower strain limit
l
3.3.12 P —tensile load at upper strain limit
u
3.3.13 ρ —density of the fiber
f
3.3.14 ρ —density of the fiber
...