ASTM D4032-94(2001)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D 4032 – 94 (Reapproved 2001)
Standard Test Method for
Stiffness of Fabric by the Circular Bend Procedure
This standard is issued under the fixed designation D 4032; 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 4. Summary of Test Method
1.1 This test method covers the determination of the stiff- 4.1 A plunger forces a flat, folded swatch of fabric through
ness of fabrics by the circular bend procedure. an orifice in a platform. The maximum force required to push
1.2 This test method is generally applicable to all types of the fabric through the orifice is an indication of the fabric
fabrics, including woven, knitted and nonwovens, of any fiber stiffness (resistance to bending).
content.
5. Significance and Use
NOTE 1—For other methods of testing for stiffness, refer to Test
5.1 Test Method D 4032 for testing stiffness of fabrics is
Methods D 1388.
considered satisfactory for quality control testing. It may also
1.3 The values stated in SI units are to be considered as
be used for acceptance testing of commercial shipments since
standard; the values in inch-pound units are included for
the test method has been used extensively in the trade field. In
information only.
cases of differences in values reported by purchaser and seller
1.4 This standard does not purport to address all of the
usingTestMethodD 4032foracceptancetesting,thestatistical
safety concerns, if any, associated with its use. It is the
bias, if any, between the laboratories of the purchaser and the
responsibility of the user of this standard to establish appro-
seller should be determined with each comparison being based
priate safety and health practices and determine the applica-
on the testing of specimens taken homogeneously from a lot of
bility of regulatory limitations prior to use.
material of the type being evaluated. Specimens should be
randomly assigned in equal numbers to each of the laborato-
2. Referenced Documents
ries.
2.1 ASTM Standards:
5.2 The circular bend procedure gives a force value related
D 123 Terminology Relating to Textiles
to fabric stiffness, simultaneously averaging stiffness in all
D 1388 Test Methods for Stiffness of Fabrics
directions.ThestiffnesstestsinTestMethodsD 1388areofthe
D 1776 Practice for Conditioning Textiles for Testing
single directional type.
5.3 The circular bend procedure is simple to perform and
3. Terminology
maybeusedforknitted,woven,ornonwovenfabrics,provided
3.1 Definitions:
gage capacity is in keeping with fabric range tested.
3.1.1 circular bend, n—simultaneous, multidirectional de-
formation of a fabric in which one face of a flat specimen
6. Apparatus
becomes concave and the other becomes convex.
6.1 Circular Bend Stiffness Tester, (Figs. 1 and 2), having
3.1.2 stiffness, n—resistance to bending.
the following parts:
3.1.3 stiffness, n—with regard to the circular bending of
6.1.1 Platform,102by102by6mm(4by4by ⁄4 in.)
textiles, resistance to multidirectional bending.
smooth-polished chrome-plated steel plate with a 38.1-mm
3.2 Fordefinitionsofothertextiletermsusedinthismethod,
(1.50-in.)diameterorifice.Thelapedgeoftheorificeshouldbe
refer to Terminology D 123.
at a 45° angle to a depth of 4.8 mm ( ⁄16 in.) (see Fig. 3).
6.1.2 Plunger, 25.4-mm (1.00-in.) diameter, mounted con-
centric with orifice, 6.4 mm (0.25 in.) clearance on all sides.
This test method is under the jurisdiction ofASTM Committee D13 onTextiles
and is the direct responsibility of Subcommittee D13.60 on Fabric Test Methods,
The bottom of the plunger should be set at 3 mm ( ⁄8 in.) above
Specific.
the top of the orifice plate. From this position, the downward
Current edition approved Jan. 15, 1994. Published April 1994. Originally
stroke length is 57 mm (2 ⁄4 in.).
published as D 4032 – 81. Last previous edition D 4032 – 93.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available from J. A. King and Co., Inc., 2620 High Point Road, Greensboro,
the ASTM website. NC 27420.
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D 4032 – 94 (2001)
FIG. 1 King Manual Operated Dial Model
between rolls of fabric and between specimens from a swatch from a roll
6.1.3 Force-Measurement Gage, dial or digital type (see
of fabric to provide a sampling plan with a meaningful producer’s risk,
9.3).
consumer’s risk, acceptable quality level, and limiting quality level.
6.1.3.1 Dial gages with maximum reading pointer in differ-
7.3 Laboratory Sample—As a laboratory sample for accep-
ent capacities ranging from 1 to 50 lbf, 0.5 to 25 kgf, or 5 to
200 N with 100 graduations minimum; or tance testing, take a full swatch 1 m (1 yd) long from the end
of each roll of fabric in the lot sample, after first discarding a
6.1.3.2 Digital gage with maximum reading “hold” feature
and capacity of 100 lbf, 50 kgf, or 500 N, with 1000 minimum of1m(1yd)of fabric from the very outside of the
rolls.
graduations minimum.
6.1.4 Actuator, manual or pneumatic.
6.2 Specimen Marking Template, (102 by 204 mm) 4.0 by 8. Number and Preparation of Test Specimens
8.0 in.
8.1 Using the specimen marking template specified in 6.2,
6.3 Stop Watch, for checking stroke speed.
mark and cut five test specimens from staggered areas of each
swatchinthelaboratorysample.Theshortsideofthespecimen
7. Sampling
must be parallel to the machine (length) direction of the fabric.
7.1 Lot Size—For sampling purposes, a lot is defined as a
Cut no specimens closer to the selvage than one tenth of the
single shipment of a single style of fabric.Alot may constitute
fabric width. Lay each specimen face down and fold the
all or part of a single customer order.
specimen once to form a square 4 by 4 in. (102 by 102 mm).
7.2 Lot Sample—As a lot sample for acceptance testing;
After folding, use the template and hand pressure to flatten the
take at random the number of rolls of fabric directed in an
crease. Handling of specimens must be kept to a minimum and
applicable material specification or other agreement between
to the edges to avoid affecting stiffness properties.
thepurchaserandthesupplier.Considerrollsoffabrictobethe
NOTE 3—When otherwise agreed upon, as when specified in an
primary sampling units.
applicable material specification, the purchaser and the seller may change
NOTE 2—An adequate specification or other agreement between the the number of test specimens per swatch from the labo
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