ASTM D6476-05

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D 6476 – 05
Standard Test Method for
Determining Dynamic Air Permeability of Inflatable Restraint
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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.
1. Scope 3. Terminology
1.1 This test method covers the procedures used to deter- 3.1 Definitions:
mine under dynamic airflow conditions the high pressure 3.1.1 For definitions of other textile and statistical terms
permeability of permeable, uncoated fabrics typically used for used in this standard, refer to Terminology D 123, D 2906 and
inflatable restraints. For the determination of air permeability Terminology D 6799.
of inflatable restraint fabrics under low pressure conditions at
4. Summary of Test Method
steady-state air flow, refer to Test Method D 737.
1.2 Procedures and apparatus other than those stated in this 4.1 A volume of dessicated compressed air at known vol-
ume and pressure passes through a fabric specimen into the
test method may be used by agreement of purchaser and
supplier with the specific deviations from the standard ac- standard atmosphere for testing textiles. During the portion of
the test cycle which simulates airbag inflation, the pressure
knowledged in the report.
1.3 The values stated in either SI units or inch-pound units differential pressure across the specimen rises to a value
corresponding to a peak inflation pressure. During the portion
are to be regarded separately as standard. The values stated in
each system are not exact equivalents; therefore, each system of the test cycle which simulates airbag deflation, the pressure
differential drops to 0 kPa as the air passes through the
must be used independently of the other.
1.4 This standard does not purport to address all of the specimen. The time to reach the maximum pressure and the
subsequent time to correspond to similar times in an airbag
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- deployment.
4.2 Software algorithms integral to the apparatus smooth
priate safety and health practices and determine the applica-
out the pressure data and determine the values for ADAP and
bility of regulatory limitations prior to use.
EXP.
2. Referenced Documents
2 5. Significance and Use
2.1 ASTM Standards:
D 123 Terminology Relating to Textiles 5.1 For matters relating to lot acceptance of commercial
shipments and conformity to specification or other standard,
D 737 Test Method forAir Permeability of Textile Products
D 1776 Practice for Conditioning Textiles for Testing refer to Section 13 of this test method.
5.2 This test method is useful in the selection and design
D 2904 Practice for InterlaboratoryTesting of aTextileTest
Method that Produces Normally Distributed Data validation of permeable, uncoatable fabrics used in inflatable
restraint cushions.The dynamic conditions and higher pressure
D 2906 Practice for Statements on Precision and Bias for
Textiles differentials of this test method may better simulate the
inflation and deflation cycle of an airbag module during
D 6799 Terminology Relating to Inflatable Restraints
E 691 Practice for Conducting an Interlaboratory Study to deployment than do the steady-state conditions of Test Method
D 737.
Determine the Precision of a Test Method
5.2.1 Only uncoated, permeable fabrics should be used. Use
of coated fabrics may yield invalid results and potentially
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This test method is under the jurisdiction ofASTM Committee D13 onTextiles
damage the test apparatus.
and is the direct responsibility of Subcommittee D13.20 on Inflatable Restraints.
5.3 Within the limits of variance expressed in Section 12,
Current edition approved April 1, 2005. Published May 2005. Originally
approved in 2000. Last previous edition approved in 2002 as D 6476–02.
this test method is useful for design validation and may be
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
suitable for incorporation in a material specification or for lot
contactASTM Customer Service at service@astm.org. ForAnnual Book ofASTM
acceptance testing of commercial shipments. Caution is ad-
Standards volume information, refer to the standard’s Document Summary page on
3
the ASTM website. vised on very low permeability fabrics or with the 200 cm .
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D6476–05
size test heat because between-laboratory precision as pre- 6.7 Filter Requirements, data sampl
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