ASTM D3882-08e1
(Test Method)Standard Test Method for Bow and Skew in Woven and Knitted Fabrics
Standard Test Method for Bow and Skew in Woven and Knitted Fabrics
SIGNIFICANCE AND USE
This test method is considered satisfactory for acceptance testing of commercial shipments.
If there are differences of practical significance between reported test results for two laboratories (or more), comparative tests should be performed to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum, the test samples to be used are as homogeneous as possible, are drawn from the material from which the disparate test results were obtained, and are randomly assigned in equal numbers to each laboratory for testing. Other fabrics with established test values may be used for this purpose. The test results from the two laboratories should be compared using a statistical test for unpaired data, at a probability level chosen prior to the testing series. If a bias is found, either its cause must be found and corrected, or future test results must be adjusted in consideration of the known bias.
Individual rolls are normally accepted or rejected on the basis of the maximum amount of bow or skew in a specific roll of fabric. The average bow or skew in a roll or lot or the range of bow or skew in a roll may be determined but are not normally used in the trade for acceptance or rejection.
Bow or skew can be induced during fabric manufacturing, dyeing, tentering, finishing, or other operations where a potential exists for uneven distribution of tensions across the fabric width. Bow and skew are more visually displeasing in colored, patterned fabrics such as plaids and horizontal stripes rather than in solid colors because the contrast makes the distortion more prominent. These defects may cause sewing problems in such fabrics and draping problems in finished products. In some cases, a specified amount of skew is needed, for example, to prevent twisting of pant legs made of twill fabric. Matching plaids from distorted patterns may create serious problems for the garment manufacturer or home sewer. Wavy or sharp breaks in t...
SCOPE
1.1 This test method covers the determination of bow and skew of filling yarns in woven fabrics and the courses in knitted fabrics.
1.2 This test method can also be used to measure the bow and skew of printed geometric designs.
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 may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
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.
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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
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Designation:D3882–08
Standard Test Method for
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Bow and Skew in Woven and Knitted Fabrics
This standard is issued under the fixed designation D3882; 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.
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´ NOTE—Section 3 was updated editorially in September 2011 in accordance with the Committee D13 Terminology policy.
1. Scope 3.2 The following terms are relevant to this standard: bow,
double bow, double hooked bow, double reverse bow, hooked
1.1 This test method covers the determination of bow and
bow, knitted fabric, skew, standard atmosphere for testing
skew of filling yarns in woven fabrics and the courses in
textiles.
knitted fabrics.
3.3 For definitions of all other textile terms seeTerminology
1.2 This test method can also be used to measure the bow
D123.
and skew of printed geometric designs.
1.3 The values stated in either SI units or inch-pound units
4. Summary of Test Method
are to be regarded separately as standard. The values stated in
4.1 Bow—A straightedge is placed across the fabric be-
each system may not be exact equivalents; therefore, each
tween two points at which a marked filling yarn, knitting
system shall be used independently of the other. Combining
course, designated printed line, or designated design meets the
values from the two systems may result in non-conformance
two selvages or edges. The greatest distance between the
with the standard.
straightedge and the marked filling line, knitting course,
1.4 This standard does not purport to address all of the
designated printed line, or designated design is measured
safety concerns, if any, associated with its use. It is the
parallel to the selvage.
responsibility of the user of this standard to establish appro-
4.2 Skew—The straight-line distortion of a marked filling
priate safety and health practices and determine the applica-
yarn, knitting course, designated printed line, or designated
bility of regulatory limitations prior to use.
design is measured from its normal perpendicular to the
2. Referenced Documents selvage or edge.
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2.1 ASTM Standards:
5. Significance and Use
D123 Terminology Relating to Textiles
5.1 This test method is considered satisfactory for accep-
D1776 Practice for Conditioning and Testing Textiles
tance testing of commercial shipments.
D2904 Practice for Interlaboratory Testing of a Textile Test
5.1.1 If there are differences of practical significance be-
Method that Produces Normally Distributed Data
tween reported test results for two laboratories (or more),
D2906 Practice for Statements on Precision and Bias for
3 comparative tests should be performed to determine if there is
Textiles
a statistical bias between them, using competent statistical
D3990 Terminology Relating to Fabric Defects
assistance. As a minimum, the test samples to be used are as
3. Terminology homogeneous as possible, are drawn from the material from
which the disparate test results were obtained, and are ran-
3.1 For all terminology related to Fabric Defects see Termi-
domlyassignedinequalnumberstoeachlaboratoryfortesting.
nology D3990.
Other fabrics with established test values may be used for this
purpose. The test results from the two laboratories should be
compared using a statistical test for unpaired data, at a
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This test method is under the jurisdiction ofASTM Committee D13 onTextiles
probability level chosen prior to the testing series. If a bias is
and is the direct responsibility of Subcommittee D13.60 on Fabric Test Methods,
Specific.
found, either its cause must be found and corrected, or future
Current edition approved July 1, 2008. Published August 2008. Originally
test results must be adjusted in consideration of the known
approved in 1980. Last previous edition approved in 2006 as D3882 – 99 (2006).
bias.
DOI: 10.1520/D3882-08.
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5.2 Individual rolls are normally accepted or rejected on the
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
basis of the maximum amount of bow or skew in a specific roll
Standards volume information, refer to the standard’s Document Summary page on
of fabric. The average bow or skew in a roll or lot or the range
the ASTM website.
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of bow or skew in a roll may be determined but are not
Withdrawn. The last approved version of this historical standard is referenced
on www.astm.org. normally used in the trade for acceptance or rejection.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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