ASTM D5822-13(2019)

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: D5822 −13 (Reapproved 2019)
Standard Test Method for
Determining Seam Strength in Inflatable Restraint
Cushions
This standard is issued under the fixed designation D5822; 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 Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
1.1 This test method covers the measurement of seam
Barriers to Trade (TBT) Committee.
efficiency and the maximum seam strength in inflatable re-
straint cushions composed of woven fabrics when a force is
2. Referenced Documents
applied perpendicular to the seam, using a grab test. For
2.1 ASTM Standards:
evaluating sewing thread, refer to Test Method D204.
D123 Terminology Relating to Textiles
1.2 This test method is restricted to seams that are either
D204 Test Methods for Sewing Threads
obtained from an inflatable restraint cushion or prepared
D1776 Practice for Conditioning and Testing Textiles
off-line, specifically for testing, using fabric blanks, not ob-
D6799 Terminology Relating to Inflatable Restraints
tained from a previously sewn cushion assembly. Seams may
include but are not limited to sewn, OPW, glued, sealed and
3. Terminology
sewn, or fused (chemically or thermally). This test method can
3.1 For all terminology relating to D13.20, Inflatable
be used for either lot testing of production cushions, or for
restraints, refer to Terminology D6799.
research and development purposes.
3.1.1 The following terms are relevant to this standard:
1.3 This test method is used when the measurement of a
seam efficiency, seam failure, seam strength.
resistance to a specified force, a breaking force, a minimum
3.2 For all other terms related to textiles, see Terminology
elongation, or a combination thereof are required to determine
D123.
the seam strength, or seam integrity of a particular fabric for
inflatable restraint use.
4. Summary of Test Method
1.4 Procedures and apparatus other than those stated in this
4.1 Specimens either taken from inflatable restraint cush-
standard may be used by agreement between purchaser and
ions or made off-line using fabric blanks, specifically for
supplier with the specific deviations from the standard ac-
testing, are destructively tested in a tensile testing machine
knowledged in the report.
under laboratory conditions to determine seam strength and
seam efficiency and nature of the failure mode.
1.5 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. The values stated in
5. Significance and Use
each system are not exact equivalents; therefore, each system
must be used independently of the other. 5.1 Seam strength testing is used for design validation and
for lot acceptance.
1.6 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5.2 This test method constitutes the conditions, procedures,
responsibility of the user of this standard to establish appro-
and equipment by which either seams taken from inflatable
priate safety, health, and environmental practices and deter-
restraint cushions, or seam types that can potentially be used
mine the applicability of regulatory limitations prior to use.
for inflatable restraint cushions are tested for seam strength,
1.7 This international standard was developed in accor-
seam efficiency, and failure mode. It is intended to be used as
dance with internationally recognized principles on standard-
a guideline in establishing a written part specification or print.
ization established in the Decision on Principles for the
The specification or agreement of purchaser and supplier may
deviate from the procedures described herein when (based on
This test method is under the jurisdiction ofASTM Committee D13 on Textiles
and is the direct responsibility of Subcommittee D13.20 on Inflatable Restraints. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Jan. 1, 2019. Published January 2019. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1995. Last previous edition approved in 2013 as D5822 – 13. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D5822-13R19. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5822 − 13 (2019)
experience) considerations of equipment, cushion design, or 7. Sampling
other factors dictate otherwise.
7.1 Seam strength testing is a destructive test and therefore
5.3 In cases of dispute arising from differences in reported
necessitates sampling procedures if used in conjunction with
test results when using this test method for acceptance testing
lot acceptance.
of commercial shipments, the purchaser and the supplier
7.2 For acceptance testing, the lot size is the quantity of
should perform comparative tests to determine if there is a
cushions produced in one day.
statistical bias between their laboratories. Competent statistical
assistance is recommended for the investigation of bias. As a
7.3 Lot Sample—For acceptance testing, take at random the
minimum, the two parties should take a group of test speci-
number of cushions directed in an applicable cushion specifi-
mens from the same lot of fabric to be evaluated, which utilize
cation or other agreement between purchaser and supplier.
a like seam assembly (or standard seam assembly) to achieve
Consider the cushions to be the primary sampling units.
seam interaction. The test specimens should then be randomly
7.4 Test Specimens—Select portions of sampled cushions
assigned in equal numbers to each laboratory for testing. If a
containing seam assemblies as directed in an applicable cush-
bias is found, either its cause must be determined and
ion specification or as agreed upon by purchaser and supplier.
corrected, or the purchaser and supplier must agree to interpret
If seam efficiency testing is to be done, select a portion of
future test results in light of the known bias.
unseamed fabric adjacent to the sampled area, from which the
5.4 Test Method D5822 is a reliable test method but
seamed specimen was taken. Wherever possible, such speci-
procedureswhichmayrequirespecialattentionareidentifiedin
mens should contain the same yarns as the seam assemblies
the precision and bias section of this test method.
that are to be placed in the clamps oriented parallel to the
traverse direction of test.
6. Apparatus
NOTE 2—Specimens are usually specified to be taken from a cushion at
6.1 Tensile Testing Machine, of the CRE, CRL or CRT type
a location on the cushion seam(s) where the greatest stresses are
conforming to Specification D76, with respect to force
anticipated. In seams involving woven fabric, this is usually where the
indication, working range, capacity, and elongation indicator,
warp or filling yarns are parallel to the seam. Cushion design may indicate
and designed for operation at a speed of 300 6 10 mm/min (12
other stress points of concern.
6 0.5 in./min); or, a variable speed drive, change gears, or
NOTE 3—Use caution in selecting specimens from areas of the cushion
interchangeable weights as required to obtain a 20 6 3-s
where the seams exhibit sharp radius turns. During seam strength testing,
these areas will exhibit uneven point loading at the edges of the test
time-to-break (see 12.4). The constant-rate-of-extension type
specimen.
of tensile testing machine is preferred in this test method.
NOTE 4—Unless otherwise specified for driver-side cushions, select
6.2 Clamp and Jaw Faces, adjustable clamps compatible
specimens taken from the perimeter seam at the 0 rad (0°), 0.79 rad (45°),
with tensile testing machine, the jaws of which have smooth,
and 1.57 rad (90°) positions, relative to the warp direction of the fabric in
the front panel.
flat, metallic gripping surfaces parallel to each other.
6.2.1 Each clamp shall have a front (or top) jaw face
7.4.1 Cut each specimen 100 61mm(4 6 0.05 in.) wide
measuring 25 6 1 mm (1.0 6 0.02 in.) perpendicular to the
by at least 150 mm (6 in.) long (Note 5) with the long
direction of the application of the force, and not less than 25
dimension parallel to the direction of testing and force appli-
nor more than 50 mm (1.0 nor more than 2.0 in.) parallel to the
cation. For seamed specimens, the seam shall be centrally
direction of the application of the force. The back, or bottom,
located perpendicular to the application of force.
jawfaceofeachclampshallbeatleastaslargeasitsmate.Use
of a larger face for the second jaw reduces the problem of front NOTE 5—The length of the specimen depends on the type of clamps
being used. The specimen should be long enough to extend through the
and back jaw misalignment.
clamps and project at least 10 mm (0.5 in.) at each end. The specimen
length may be calculated using Eq 1 or Eq 2:
NOTE 1—Front (or top) faces measuring 25 by 50-mm (1.0 by 2.0-in.)
will not necessarily give the same value as 25 by 25-mm (1.0 by 1.0-in.)
Specimen length, mm 5 C12W (1)
faces. For many materials, the former are preferable because of the larger
gripping area which tends to reduce slippage.While both sizes of gripping
Specimen length, in. 5 K12W (2)
surface are permitted, the face sizes used must be the same for all samples
in the test and must be recorded in the report. where:
C = 95 mm (constant based on a gage length of 75 plus 20
6.2.2 At least one clamp should be supported by a free
mm for projections beyond the clamp),
swivel or universal joint to allow the clamp to rotate in the
K = 4in.(constantbasedonagagelengthof3plus1in.for
plane of the fabric.
projections beyond the clamps), and
6.3 For inflatable restraints, all test equipment used in
W = jaw face width in direction of force, mm (in.).
accordance with this test method shall be certified for calibra-
7.4.2 To aid in aligning the specimens in the clamps of the
tion annually by an independent agency or equipment manu-
facturer whose results are traceable to the National Institute of tensile testing machine, draw vertical lines parallel to the long
direction (and along a yarn of woven fabric) located 37 6 1
Science and Technology (NIST) or other national standards
laboratory.The test parameters of the equipment shall be tested mm (1.5 6 0.02 in.) in from the edge of both sides of the
specimen. The parallel lines serve as a guide to ensure that the
within the operating ranges covered in the cushion specifica-
tion or equivalent document. same yarns in the direction of test are gripped in both clamps.
D5822 − 13 (2019)
8. Conditioning 9.6 Record the maximum seam
...