ASTM D4032-94

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
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Designation: D 4032 – 94
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 5. Significance and Use
1.1 This test method covers the determination of the stiff- 5.1 Test Method D 4032 for testing stiffness of fabrics is
ness of fabrics by the circular bend procedure. considered satisfactory for quality control testing. It may also
1.2 This test method is generally applicable to all types of be used for acceptance testing of commercial shipments since
fabrics, including woven, knitted and nonwovens, of any fiber the test method has been used extensively in the trade field. In
content. cases of differences in values reported by purchaser and seller
using Test Method D 4032 for acceptance testing, the statistical
NOTE 1—For other methods of testing for stiffness, refer to Test
bias, if any, between the laboratories of the purchaser and the
Methods D 1388.
seller should be determined with each comparison being based
1.3 The values stated in SI units are to be considered as
on the testing of specimens taken homogeneously from a lot of
standard; the values in inch-pound units are included for
material of the type being evaluated. Specimens should be
information only.
randomly assigned in equal numbers to each of the laborato-
1.4 This standard does not purport to address all of the
ries.
safety concerns, if any, associated with its use. It is the
5.2 The circular bend procedure gives a force value related
responsibility of the user of this standard to establish appro-
to fabric stiffness, simultaneously averaging stiffness in all
priate safety and health practices and determine the applica-
directions. The stiffness tests in Test Methods D 1388 are of the
bility of regulatory limitations prior to use.
single directional type.
5.3 The circular bend procedure is simple to perform and
2. Referenced Documents
may be used for knitted, woven, or nonwoven fabrics, provided
2.1 ASTM Standards:
gage capacity is in keeping with fabric range tested.
D 123 Terminology Relating to Textiles
D 1388 Test Methods for Stiffness of Fabrics
6. Apparatus
D 1776 Practice for Conditioning Textiles for Testing 3
6.1 Circular Bend Stiffness Tester, (Figs. 1 and 2), having
the following parts:
3. Terminology
6.1.1 Platform,102 by 102 by6mm(4by4by ⁄4 in.)
3.1 Definitions:
smooth-polished chrome-plated steel plate with a 38.1-mm
3.1.1 circular bend, n—simultaneous, multidirectional de-
(1.50-in.) diameter orifice. The lap edge of the orifice should be
formation of a fabric in which one face of a flat specimen
at a 45° angle to a depth of 4.8 mm ( ⁄16 in.) (see Fig. 3).
becomes concave and the other becomes convex.
6.1.2 Plunger, 25.4-mm (1.00-in.) diameter, mounted con-
3.1.2 stiffness, n—resistance to bending.
centric with orifice, 6.4 mm (0.25 in.) clearance on all sides.
3.1.3 stiffness, n—with regard to the circular bending of
The bottom of the plunger should be set at 3 mm ( ⁄8 in.) above
textiles, resistance to multidirectional bending.
the top of the orifice plate. From this position, the downward
3.2 For definitions of other textile terms used in this method,
stroke length is 57 mm (2 ⁄4 in.).
refer to Terminology D 123.
6.1.3 Force-Measurement Gage, dial or digital type (see
9.3).
4. Summary of Test Method
6.1.3.1 Dial gages with maximum reading pointer in differ-
4.1 A plunger forces a flat, folded swatch of fabric through
ent capacities ranging from 1 to 50 lbf, 0.5 to 25 kgf, or 5 to
an orifice in a platform. The maximum force required to push
200 N with 100 graduations minimum; or
the fabric through the orifice is an indication of the fabric
6.1.3.2 Digital gage with maximum reading “hold” feature
stiffness (resistance to bending).
and capacity of 100 lbf, 50 kgf, or 500 N, with 1000
graduations minimum.
This test method is under the jurisdiction of ASTM Committee D-13 on Textiles
6.1.4 Actuator, manual or pneumatic.
and is the direct responsibility of Subcommittee D13.60 on Fabric Test Methods,
Specific.
Current edition approved Jan. 15, 1994. Published April 1994. Originally
published as D 4032 – 81. Last previous edition D 4032 – 93. Available from J. A. King and Co., Inc., 2620 High Point Road, Greensboro,
Annual Book of ASTM Standards, Vol 07.01. NC 27420.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 4032
FIG. 1 King Manual Operated Dial Model
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
swatch in the laboratory sample. The short side of the specimen
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. A lot 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.
the purchaser and the supplier. Consider rolls of fabric to be the
primary sampling units.
NOTE 3—When otherwise agreed upon, as when specified in an
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 laboratory sample.
purchaser and the supplier requires taking into account the variability
between rolls of fabric and between specimens from a swatch from a roll NOTE 4—Fabrics may also be tested face-to-face when the technical
of fabric to provide a sampling plan with a meaningful producer’s risk, back is used for the outer surface or when there are significant differences
consumer’s risk, acceptable quality level, and limiting quality level.
in face and back surface properties. In reporting, indicate that the fabric
was tested face-to-face.
7.3 Laboratory
...