ASTM D6476-02

Standard Test Method for Determining Dynamic Air Permeability of Inflatable Restraint Fabrics

SCOPE
1.1 This test method covers the procedures used to determine under dynamic airflow conditions the high pressure permeability of permeable fabrics typically used for inflatable restraints. For the determination of air permeability of inflatable restraint fabrics under low pressure conditions at steady-state air flow, refer to Test Method D737.
1.2 Procedures and apparatus other than those stated in this test method may be used by agreement of purchaser and supplier with the specific deviations from the standard acknowledged in the report
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other.
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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Apr-2002
• ICS: 43.040.60 - Bodies and body components
• ICS: 59.080.30 - Textile fabrics
• Technical Committee: D13 - Textiles
• Drafting Committee: D13.20 - Inflatable Restraints

Relations

• Replaced By: ASTM D6476-05 - Standard Test Method for Determining Dynamic Air Permeability of Inflatable Restraint Fabrics
• Effective Date: 01-Apr-2005
• Referred By: ASTM D5446-08(2019) - Standard Practice for Determining Physical Properties of Fabrics, Yarns, and Sewing Thread Used in Inflatable Restraints
• Effective Date: 10-Apr-2002

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D 6476 – 02
Standard Test Method for
Determining Dynamic Air Permeability of Inflatable Restraint
1
Fabrics
This standard is issued under the fixed designation D 6476; 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 (e) indicates an editorial change since the last revision or reapproval.
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1. Scope Determine the Precision of a Test Method
1.1 This test method covers the procedures used to deter-
3. Terminology
mine under dynamic airflow conditions the high pressure
3.1 Definitions:
permeability of permeable fabrics typically used for inflatable
3.1.1 For definitions of other textile and statistical terms
restraints. For the determination of air permeability of inflat-
used in this standard, refer to Terminology D 123, D 2906 and
able restraint fabrics under low pressure conditions at steady-
Terminology D 6799.
state air flow, refer to Test Method D 737.
1.2 Procedures and apparatus other than those stated in this
4. Summary of Test Method
test method may be used by agreement of purchaser and
4.1 A volume of dessicated compressed air at known vol-
supplier with the specific deviations from the standard ac-
ume and pressure passes through a fabric specimen into the
knowledged in the report.
standard atmosphere for testing textiles. During the portion of
1.3 The values stated in either SI units or inch-pound units
the test cycle which simulates airbag inflation, the pressure
are to be regarded separately as standard. The values stated in
differential pressure across the specimen rises to a value
each system are not exact equivalents; therefore, each system
corresponding to a peak inflation pressure. During the portion
must be used independently of the other.
of the test cycle which simulates airbag deflation, the pressure
1.4 This standard does not purport to address all of the
differential drops to 0 kPa as the air passes through the
safety concerns, if any, associated with its use. It is the
specimen. The time to reach the maximum pressure and the
responsibility of the user of this standard to establish appro-
subsequent time to correspond to similar times in an airbag
priate safety and health practices and determine the applica-
deployment.
bility of regulatory limitations prior to use.
4.2 Software algorithms integral to the apparatus smooth
2. Referenced Documents out the pressure data and determine the values for ADAP and
EXP.
2.1 ASTM Standards:
2
D 123 Terminology Relating to Textiles
5. Significance and Use
D 737 Test Method for Air Permeability of Textile Prod-
5.1 For matters relating to lot acceptance of commercial
2
ucts
2 shipments and conformity to specification or other standard,
D 1776 Practice for Conditioning Textiles for Testing
refer to Section 13 of this test method.
D 2904 Practice for Interlaboratory Testing of a Textile Test
2 5.2 This test method is useful in the selection and design
Method that Produces Normally Distributed Data
validation of fabrics used in inflatable restraint cushions. The
D 2906 Practice for Statements on Precision and Bias for
2 dynamicconditionsandhigherpressuredifferentialsofthistest
Textiles
3 method may better simulate the inflation and deflation cycle of
D 6799 Terminology Relating to Inflatable Restraints
an airbag module during deployment than do the steady-state
E 691 Practice for Conducting an Interlaboratory Study to
conditions of Test Method D 737.
5.3 Within the limits of variance expressed in Section 12,
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this test method is useful for design validation and may be
This test method is under the jurisdiction ofASTM Committee D13 onTextiles
and is the direct responsibility of Subcommittee D13.20 on Inflatable Restraints.
suitable for incorporation in a material specification or for lot
Current edition approved April 10, 2002. Published June 2002. Originally
published as D 6476–00. Last previous edition D 6476–00a.
2
Annual Book of ASTM Standards, Vol 07.01.
3
4
Annual Book of ASTM Standards, Vol 07.02.
Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D 6476
acceptance testing of commercial shipments. Caution is ad- 6.6 Data Acquisition System, suitable for recording the
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vised on very low permeability fabrics or with the 200 cm . output of the pressure transducers versus elapsed time of
size test heat because between-laboratory precision as pre- airflow.
sented in Section 12 may be as high as 21 %. 6.7 Filter Requirements, data sampling rate, transducer
frequency response, and amplifier frequency response shall be
5.4 This test method may be used for ma
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