ASTM D1388-23

Standard Test Method for Stiffness of Fabrics

SIGNIFICANCE AND USE
5.1 In general, these procedures are more suitable for testing woven fabrics than knit fabrics.  
5.2 Both test options in this test method are considered satisfactory for acceptance testing of commercial shipments since current estimates of between-laboratory precision are acceptable and the method is used extensively in the trade for acceptance testing.  
5.2.1 In case of a dispute arising from differences in reported test results when using this test method for acceptance testing of commercial shipments, the purchaser and the supplier should conduct comparative tests to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the two parties should take a group of test specimens that are as homogeneous as possible and that are from a lot of material of the type in question. Test specimens should then be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories should be compared using the appropriate statistical analysis and an acceptable probability level chosen by the two parties before testing is begun. If a bias is found, either its cause must be found and corrected or the purchaser and the supplier must agree to interpret future test results with consideration to the known bias.  
5.3 The stiffness of a fabric may change with storage.  
5.4 No evidence has been found showing that bending length is dependent on the width of the test specimen. The tendency for specimens to curl or twist will affect the result, because of the rigidity provided at the edge of the specimen. Consequently, the wider the strip, the less important is the edge effect. For fabrics having only a slight tendency to curl, a 2.5 cm wide strip has been found to be satisfactory. As the tendency to curl increases, this width may be increased (see Note 10).  
5.5 This method differs from Test Method F3260 which requires tracking of...
SCOPE
1.1 This test method covers the measurement of stiffness properties of fabrics. Bending length is measured and flexural rigidity is calculated. Two procedures are provided.  
1.1.1 Option A—Cantilever Test, employing the principle of cantilever bending of the fabric under its own mass.  
1.1.2 Option B—Heart Loop Test, employing the principle of a loop formed in a fabric strip and hung vertically.  
1.2 This test method applies to most fabrics including woven fabrics, air bag fabrics, blankets, napped fabrics, knitted fabrics, layered fabrics, pile fabrics. The fabrics may be untreated, heavily sized, coated, resin-treated, or otherwise treated.  
1.2.1 This method may be used to determine the stiffness of nonwoven materials (for example, hydroentangled, dry laid, needlepunch, resin bonded, thermal, and wet laid) or refer to Test Method D5732. To determine the stiffness of medical textiles (for example, surgical mesh, films, and membranes), refer to Test Method F3260.  
Note 1: The formula to calculate flexural rigidity in D5732-95 (2001) is incorrect and should not be used. Utilize the formula presented in 11.5 of Test Method D1388.  
1.3 Units—The values stated in SI units are to be regarded as the standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
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 appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 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...

General Information

• Status: Published
• Publication Date: 31-Jul-2023
• ICS: 59.080.30 - Textile fabrics
• Technical Committee: D13 - Textiles
• Drafting Committee: D13.60 - Fabric Physical Test Methods B

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: D1388 − 23
Standard Test Method for
1
Stiffness of Fabrics
This standard is issued under the fixed designation D1388; 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* mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This test method covers the measurement of stiffness
properties of fabrics. Bending length is measured and flexural
2. Referenced Documents
rigidity is calculated. Two procedures are provided.
2
2.1 ASTM Standards:
1.1.1 Option A—Cantilever Test, employing the principle of
D123 Terminology Relating to Textiles
cantilever bending of the fabric under its own mass.
D1776 Practice for Conditioning and Testing Textiles
1.1.2 Option B—Heart Loop Test, employing the principle
D2904 Practice for Interlaboratory Testing of a Textile Test
of a loop formed in a fabric strip and hung vertically.
Method that Produces Normally Distributed Data (With-
1.2 This test method applies to most fabrics including 3
drawn 2008)
woven fabrics, air bag fabrics, blankets, napped fabrics, knitted
D2906 Practice for Statements on Precision and Bias for
fabrics, layered fabrics, pile fabrics. The fabrics may be 3
Textiles (Withdrawn 2008)
untreated, heavily sized, coated, resin-treated, or otherwise
D3776 Test Methods for Mass Per Unit Area (Weight) of
treated.
Fabric
1.2.1 This method may be used to determine the stiffness of
D4850 Terminology Relating to Fabrics and Fabric Test
nonwoven materials (for example, hydroentangled, dry laid,
Methods
needlepunch, resin bonded, thermal, and wet laid) or refer to
D5732 Test Method for Stiffness of Nonwoven Fabrics
Test Method D5732. To determine the stiffness of medical 3
Using the Cantilever Test (Withdrawn 2008)
textiles (for example, surgical mesh, films, and membranes),
F3260 Test Method for Determining the Flexural Stiffness of
refer to Test Method F3260.
Medical Textiles
NOTE 1—The formula to calculate flexural rigidity in D5732-95 (2001)
3. Terminology
is incorrect and should not be used. Utilize the formula presented in 11.5
of Test Method D1388.
3.1 For all terminology relating to D13.59, Fabric Test
1.3 Units—The values stated in SI units are to be regarded
Methods, General, refer to Terminology D4850.
as the standard. The values given in parentheses after SI units
3.1.1 The following terms are relevant to this standard:
are provided for information only and are not considered
bending length, cross-machine direction, (CD), fabric, flexural
standard.
rigidity, machine direction, (MD), stiffness.
1.4 This standard does not purport to address all of the
NOTE 2—Machine direction (MD) may represent wale and warp
safety concerns, if any, associated with its use. It is the
directions and cross-machine direction (CD) may represent course and
responsibility of the user of this standard to establish appro- weft directions in knit fabrics or woven fabrics or both.
priate safety, health, and environmental practices and deter-
3.2 For all other terminology related to textiles, refer to
mine the applicability of regulatory limitations prior to use.
Terminology D123.
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard- 4. Summary of Test Method Options
ization established in the Decision on Principles for the
4.1 Option A, Cantilever Test—A specimen is slid at a
Development of International Standards, Guides and Recom-
specified rate in a direction parallel to its long dimension, until
1 2
This test method is under the jurisdiction of ASTM Committee D13 on Textiles For referenced ASTM standards, visit the ASTM website, www.astm.org, or
and is the direct responsibility of Subcommittee D13.60 on Fabric Physical Test contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Methods B. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Aug. 1, 2023. Published August 2023. Originally the ASTM website.
3
approved in 1956. Last previous edition approved in 2018 as D1388–18. DOI: The last approved version of this historical standard is referenced on
10.1520/D1388-23. www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. Un
...

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: D1388 − 18 D1388 − 23
Standard Test Method for
1
Stiffness of Fabrics
This standard is issued under the fixed designation D1388; 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 Scope*
1.1 This test method covers the measurement of stiffness properties of fabrics. Bending length is measured and flexural rigidity
is calculated. Two procedures are provided.
1.1.1 Option A—Cantilever Test, employing the principle of cantilever bending of the fabric under its own mass.
1.1.2 Option B—Heart Loop Test, employing the principle of a loop formed in a fabric strip and hung vertically.
1.2 This test method applies to most fabrics including woven fabrics, air bag fabrics, blankets, napped fabrics, knitted fabrics,
layered fabrics, pile fabrics. The fabrics may be untreated, heavily sized, coated, resin-treated, or otherwise treated.
1.2.1 This method may be used to determine the stiffness of nonwoven materials (for example, hydroentangled, dry laid,
needlepunch, resin bonded, thermal, and wet laid) or refer to Test Method D5732. To determine the stiffness of medical textiles
(for example, surgical mesh, films, and membranes), refer to Test Method F3260.
NOTE 1—The formula to calculate flexural rigidity in D5732-95 (2001) is incorrect and should not be used. Utilize the formula presented in 11.5 of Test
Method D1388.
1.3 Units—The values stated in SI units are to be regarded as the standard. The U.S. customary units may be approximate.values
given in parentheses after SI units are provided for information only and are not considered standard.
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 appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.5 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:
1
This test method is under the jurisdiction of ASTM Committee D13 on Textiles and is the direct responsibility of Subcommittee D13.60 on Fabric Test Methods,
SpecificPhysical Test Methods B.
Current edition approved July 1, 2018Aug. 1, 2023. Published October 2018August 2023. Originally approved in 1956. Last previous edition approved in 20142018 as
ɛ1
D1388–14–18. . DOI: 10.1520/D1388-18.10.1520/D1388-23.
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.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D1388 − 23
D123 Terminology Relating to Textiles
D1776 Practice for Conditioning and Testing Textiles
3
D2904 Practice for Interlaboratory Testing of a Textile Test Method that Produces Normally Distributed Data (Withdrawn 2008)
3
D2906 Practice for Statements on Precision and Bias for Textiles (Withdrawn 2008)
D3776 Test Methods for Mass Per Unit Area (Weight) of Fabric
D4850 Terminology Relating to Fabrics and Fabric Test Methods
3
D5732 Test Method for Stiffness of Nonwoven Fabrics Using the Cantilever Test (Withdrawn 2008)
F3260 Test Method for Determining the Flexural Stiffness of Medical Textiles
3. Terminology
3.1 For all terminology relating to D13.59, Fabric Test Methods, General, refer to Terminology D4850.
3.1.1 The following terms are relevant to this standard: bending length, cross-machine direction, CD,(CD), fabric, flexural rigidity,
machine direction, MD,(MD), stiffness.
NOTE 2—Machine direction (MD) may represent wale and warp directions and cross-machine direction (CD) may represent course and weft directions
in knit fabrics or woven fabrics
...