ASTM D2646-24

Standard Guide for Backing Fabric Characteristics of Pile Yarn Floor Coverings

SIGNIFICANCE AND USE
5.1 These test methods may be used for acceptance testing of commercial shipments; however, caution is advised because information about between interlaboratory precision is incomplete. Comparative tests as directed in 5.1.1 may be advisable.  
5.1.1 If there are differences of practical significance between reported test results for two laboratories (or more), comparative tests should be performed to determine if there is statistical bias between them using competent statistical assistance. As a minimum, use test samples for such comparative tests that are as homogeneous as possible, drawn from the same lot of material as the samples that resulted in the disparate results during initial testing, and that are randomly assigned in equal numbers to each laboratory for testing. The test results from the laboratories should be compared using statistical test for unpaired data at a probability level chosen prior to the testing series. If a bias is found either its cause must be found and corrected, or future test results for that material must be adjusted in consideration of the known bias.  
5.2 These test methods are useful to evaluate quality and cost control during the manufacture of pile yarn floor covering.  
5.3 The significance and uses of particular properties and test methods are discussed in the appropriate sections of the specified test methods.
SCOPE
1.1 This guide covers the procedures listed as follows for testing woven, knitted and nonwoven backing fabrics designed for use in the manufacture of pile yarn floor coverings. The procedures appear in the following order:    
Section  
Bow and Skewness of Woven Fabrics  
8  
Breaking Force of Woven and Nonwoven Fabrics  
15  
Breaking Force After Tufting of Woven and Nonwoven Fabrics  
16  
Extractable Matter  
9  
Fabric Count of Woven Fabrics  
12  
Fabric Count of Knitted Fabrics  
13  
Length of Woven Fabrics  
11  
Mass per Unit Area (Weight) of Woven Fabrics  
14  
Width of Woven Fabrics  
10  
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
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-Dec-2023
• ICS: 59.080.30 - Textile fabrics
• Technical Committee: D13 - Textiles
• Drafting Committee: D13.21 - Pile Floor Coverings

Relations

• Replaces: ASTM D2646-18 - Standard Guide for Backing Fabric Characteristics of Pile Yarn Floor Coverings
• Effective Date: 01-Jan-2024
• Referred By: ASTM D5684-19a - Standard Terminology Relating to Pile Floor Coverings
• Effective Date: 01-Jan-2024
• Referred By: ASTM D7983-17(2022) - Standard Test Method for Shrinkage of Carpet Backing Fabrics
• Effective Date: 01-Jan-2024
• Referred By: ASTM D6719-22e1 - Standard Guide for Standard Test Methods and Practices for Evaluating Pile Yarn Floor Covering
• Effective Date: 01-Jan-2024

Overview

ASTM D2646-24 is the latest revision of the internationally recognized standard guide for assessing the backing fabric characteristics of pile yarn floor coverings. Published by ASTM International, this guide outlines procedures for testing woven, knitted, and nonwoven backing fabrics specifically designed for use in carpet and textile floor coverings with pile yarns. The standard provides methodologies for determining essential physical properties, supporting quality control and ensuring product consistency within the flooring industry. This document is developed in accordance with internationally agreed standardization principles, aligning with the WTO Technical Barriers to Trade (TBT) Committee guidelines.

Key Topics

ASTM D2646-24 encompasses a comprehensive set of test methods and acceptance criteria for floor covering backing fabrics, including:

• Bow and Skewness of woven and knitted fabrics
• Extractable Matter to evaluate components added during production
• Width and Length of woven fabrics, ensuring dimensional accuracy
• Fabric Count for both woven and knitted fabrics, supporting structural evaluations
• Mass per Unit Area (Weight) of woven fabrics
• Breaking Force for both woven and nonwoven fabrics, before and after tufting

The standard also emphasizes:

• Sampling procedures for laboratory analysis, including defining lot and laboratory samples
• Use of statistical methods to identify and address potential laboratory biases
• Conditioning procedures patterned after standardized textile testing atmospheres

Applications

ASTM D2646-24 is vital to a range of stakeholders in the floor covering sector:

• Manufacturers rely on the guide to maintain consistent quality, control costs, and ensure products meet industry specifications.
• Quality assurance and compliance teams use these test methods for the acceptance testing of commercial shipments of pile yarn floor coverings.
• Laboratories apply the standard’s detailed test methods to assess the physical characteristics of backing fabrics, including strength, mass, fabric count, and dimensional stability.
• Purchasers and suppliers benefit from shared terminology and clearly defined acceptance criteria, which facilitate transparent transactions and contracts.
• Product development teams utilize the standard to compare material performance and support innovation in carpet and textile floor covering products.

By defining best practices for sampling, testing, and comparing results between laboratories, the standard supports reliable and repeatable results that underpin international trade and market access.

Related Standards

ASTM D2646-24 references several other ASTM standards to ensure harmonization across textile and floor covering testing:

• ASTM D2257: Extractable Matter in Textiles
• ASTM D3773/D3773M: Length of Woven Fabric
• ASTM D3774: Width of Textile Fabric
• ASTM D3775: End (Warp) and Pick (Filling) Count of Woven Fabrics
• ASTM D3776/D3776M: Mass Per Unit Area (Weight) of Fabric
• ASTM D3882: Bow and Skew in Woven and Knitted Fabrics
• ASTM D3887: Tolerance for Knitted Fabrics
• ASTM D5034: Breaking Strength and Elongation of Textile Fabrics (Grab Test)
• ASTM D5684: Terminology Relating to Pile Floor Coverings
• ASTM D123: Terminology Relating to Textiles
• ASTM D1776/D1776M: Conditioning and Testing Textiles

Using these related standards alongside ASTM D2646-24 ensures a robust, consistent approach to evaluating backing fabric characteristics, supporting both domestic quality goals and global trade requirements.

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Keywords: ASTM D2646-24, backing fabric, pile yarn floor coverings, carpet, woven backing, nonwoven fabric, fabric count, extractable matter, textile standards, breaking force, mass per unit area, floor covering industry, quality control.

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: D2646 − 24
Standard Guide for
Backing Fabric Characteristics of Pile Yarn Floor Coverings
This standard is issued under the fixed designation D2646; 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 D2257 Test Method for Extractable Matter in Textiles
D3773/D3773M Test Methods for Length of Woven Fabric
1.1 This guide covers the procedures listed as follows for
D3774 Test Method for Width of Textile Fabric
testing woven, knitted and nonwoven backing fabrics designed
D3775 Test Method for End (Warp) and Pick (Filling) Count
for use in the manufacture of pile yarn floor coverings. The
of Woven Fabrics
procedures appear in the following order:
D3776/D3776M Test Methods for Mass Per Unit Area
Section
(Weight) of Fabric
D3882 Test Method for Bow and Skew in Woven and
Bow and Skewness of Woven Fabrics 8
Breaking Force of Woven and Nonwoven Fabrics 15
Knitted Fabrics
Breaking Force After Tufting of Woven and Nonwoven Fabrics 16
D3887 Specification for Tolerance for Knitted Fabrics
Extractable Matter 9
Fabric Count of Woven Fabrics 12 (Withdrawn 2017)
Fabric Count of Knitted Fabrics 13
D5034 Test Method for Breaking Strength and Elongation of
Length of Woven Fabrics 11
Textile Fabrics (Grab Test)
Mass per Unit Area (Weight) of Woven Fabrics 14
Width of Woven Fabrics 10 D5684 Terminology Relating to Pile Floor Coverings
1.2 The values stated in inch-pound units are to be regarded
3. Terminology
as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only
3.1 For definitions of terms relating to Pile Floor Coverings,
and are not considered standard.
D13.21, refer to Terminology D5684.
3.1.1 The following terms are relevant to this standard:
1.3 This standard does not purport to address all of the
backing fabric, carpet, dents per unit width, extractable matter,
safety concerns, if any, associated with its use. It is the
finished, finished pile yarn floor covering, floor covering,
responsibility of the user of this standard to establish appro-
nonwoven fabric, pile, pile yarn floor covering, textile floor
priate safety, health, and environmental practices and deter-
covering, tufted fabric, wale, wires per unit width.
mine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accor-
3.2 For all other terminology related to textiles, refer to
dance with internationally recognized principles on standard-
Terminology D123.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
4. Summary of Test Methods, General
mendations issued by the World Trade Organization Technical
4.1 A summary of the directions prescribed for the determi-
Barriers to Trade (TBT) Committee.
nation of specific properties is stated in the appropriate sections
of specific test methods.
2. Referenced Documents
2.1 ASTM Standards:
5. Significance and Use
D123 Terminology Relating to Textiles
5.1 These test methods may be used for acceptance testing
D1776/D1776M Practice for Conditioning and Testing Tex-
of commercial shipments; however, caution is advised because
tiles
information about between interlaboratory precision is incom-
plete. Comparative tests as directed in 5.1.1 may be advisable.
This guide is under the jurisdiction of ASTM Committee D13 on Textiles and
5.1.1 If there are differences of practical significance be-
is the direct responsibility of Subcommittee D13.21 on Pile Floor Coverings.
tween reported test results for two laboratories (or more),
Current edition approved Jan. 1, 2024. Published February 2024. Originally
comparative tests should be performed to determine if there is
approved in 1967. Last previous edition approved in 2018 as D2646 – 18. DOI:
10.1520/D2646-24.
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 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
D2646 − 24
between rolls or pieces of floor covering and between specimens from a
statistical bias between them using competent statistical assis-
roll or pieces of floor covering to provide a sampling plan with a
tance. As a minimum, use test samples for such comparative
meaningful producer’s risk, consumer’s risk, acceptable quality level, and
tests that are as homogeneous as possible, drawn from the same
limiting quality level.
lot of material as the samples that resulted in the disparate
6.2 Laboratory Sample—For acceptance testing, take a
results during initial testing, and that are randomly assigned in
sample from a roll approximately 1.5 yd (1.5 m) long extend-
equal numbers to each laboratory for testing. The test results
ing the width of the material from each roll or piece in the lot,
from the laboratories should be compared using statistical test
unless otherwise specified in the specific test method. For rolls
for unpaired data at a probability level chosen prior to the
of floor covering, take a sample that will exclude fabric from
testing series. If a bias is found either its cause must be found
the outer wrap of the roll or the inner wrap around the core.
and
...

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: D2646 − 18 D2646 − 24
Standard Guide for
Backing Fabric Characteristics of Pile Yarn Floor Coverings
This standard is issued under the fixed designation D2646; 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 guide covers the procedures listed as follows for testing woven, knitted and nonwoven backing fabrics designed for use
in the manufacture of pile yarn floor coverings. The procedures appear in the following order:
Section
Bow and Skewness of Woven Fabrics 8
Breaking Force of Woven and Nonwoven Fabrics 15
Breaking Force After Tufting of Woven and Nonwoven Fabrics 16
Extractable Matter 9
Fabric Count of Woven Fabrics 12
Fabric Count of Knitted Fabrics 13
Length of Woven Fabrics 11
Mass per Unit Area (Weight) of Woven Fabrics 14
Width of Woven Fabrics 10
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
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
2.1 ASTM Standards:
D123 Terminology Relating to Textiles
D1776D1776/D1776M Practice for Conditioning and Testing Textiles
D2257 Test Method for Extractable Matter in Textiles
D3773D3773/D3773M Test Methods for Length of Woven Fabric
D3774 Test Method for Width of Textile Fabric
D3775 Test Method for End (Warp) and Pick (Filling) Count of Woven Fabrics
D3776D3776/D3776M Test Methods for Mass Per Unit Area (Weight) of Fabric
This guide is under the jurisdiction of ASTM Committee D13 on Textiles and is the direct responsibility of Subcommittee D13.21 on Pile Floor Coverings.
Current edition approved Jan. 1, 2018Jan. 1, 2024. Published February 2018February 2024. Originally approved in 1967. Last previous edition approved in 20112018 as
D2646 – 11.D2646 – 18. DOI: 10.1520/D2646-18.10.1520/D2646-24.
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
D2646 − 24
D3882 Test Method for Bow and Skew in Woven and Knitted Fabrics
D3887 Specification for Tolerance for Knitted Fabrics (Withdrawn 2017)
D5034 Test Method for Breaking Strength and Elongation of Textile Fabrics (Grab Test)
D5684 Terminology Relating to Pile Floor Coverings
3. Terminology
3.1 For definitions of terms relating to Pile Floor Coverings, D13.21, refer to Terminology D5684.
3.1.1 The following terms are relevant to this standard: backing fabric, carpet, dents per unit width, extractable matter, finished,
finished pile yarn floor covering, floor covering, nonwoven fabric, pile, pile yarn floor covering, textile floor covering, tufted fabric,
wale, wires per unit width.
3.2 For all other terminology related to textiles, refer to Terminology D123.
4. Summary of Test Methods, General
4.1 A summary of the directions prescribed for the determination of specific properties is stated in the appropriate sections of
specific test methods.
5. Significance and Use
5.1 These test methods may be used for acceptance testing of commercial shipments; however, caution is advised because
information about between interlaboratory precision is incomplete. Comparative tests as directed in 5.1.1 may be advisable.
5.1.1 If there are differences of practical significance between reported test results for two laboratories (or more), comparative tests
should be performed to determine if there is statistical bias between them using competent statistical assistance. As a minimum,
use test samples for such comparative tests that are as homogeneous as possible, drawn from the same lot of material as the samples
that resulted in the disparate results during initial testing, and that are randomly assigned in equal numbers to each laboratory for
testing. The test results from the laboratories should be compared using statistical test for unpaired data at a probability level
chosen prior to the testing series. If a bias is found either its cause must be found and corrected, or future test results for that
material must be adjusted in consideration of the known bias.
5.2 These test methods are useful to evaluate quality and cost control during the manufacture of pile yarn floor covering.
5.3 The significance and uses of particular properties and test methods are discussed in the appropriate sections of the specified
test methods.
6. Sampling
6.1 Lot Sample—As a lot sample for acceptance testing, take at random the number of rolls or pieces, as directed in an applicable
material specification or other agreement between the purchaser and the supplier. Consider the rolls or pieces of material to be the
primary s
...