Standard Test Method for Bow and Skew in Woven and Knitted Fabrics

SIGNIFICANCE AND USE
5.1 This test method is considered satisfactory for acceptance testing of commercial shipments.  
5.1.1 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.  
5.2 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.  
5.3 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 ...
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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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
Designation: D3882 − 08 (Reapproved 2016)
Standard Test Method for
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.
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—Astraightedgeisplacedacrossthefabricbetween
each system may not be exact equivalents; therefore, each
two points at which a marked filling yarn, knitting course,
system shall be used independently of the other. Combining
designated printed line, or designated design meets the two
values from the two systems may result in non-conformance
selvages or edges. The greatest distance between the straight-
with the standard.
edge and the marked filling line, knitting course, designated
1.4 This standard does not purport to address all of the
printed line, or designated design is measured parallel to the
safety concerns, if any, associated with its use. It is 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
selvage or edge.
2. Referenced Documents
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 (With-
3 tween reported test results for two laboratories (or more),
drawn 2008)
comparative tests should be performed to determine if there is
D2906 Practice for Statements on Precision and Bias for
3 a statistical bias between them, using competent statistical
Textiles (Withdrawn 2008)
assistance. As a minimum, the test samples to be used are as
D3990 Terminology Relating to Fabric Defects
homogeneous as possible, are drawn from the material from
which the disparate test results were obtained, and are ran-
3. Terminology
domlyassignedinequalnumberstoeachlaboratoryfortesting.
3.1 For all terminology related to Fabric Defects see Termi-
Other fabrics with established test values may be used for this
nology D3990.
purpose. The test results from the two laboratories should be
compared using a statistical test for unpaired data, at a
This test method is under the jurisdiction ofASTM Committee D13 on Textiles
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,
found, either its cause must be found and corrected, or future
Specific.
test results must be adjusted in consideration of the known
Current edition approved July 1, 2016. Published July 2016. Originally approved
ε1
in 1980. Last previous edition approved in 2012 as D3882 – 08(2012) . DOI:
bias.
10.1520/D3882-08R16.
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.
3 of bow or skew in a roll may be determined but are not
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
D3882 − 08 (2016)
5.3 Bow or skew can be induced during fabric accordance with Practice D1776 or, if applicable, in the
manufacturing, dyeing, tentering, finishing, or other operations specified atmosphere in which the testing is to be performed.
where a potential exists for uneven distribution of tensions 8.1.1 When full rolls or bolts of fabric cannot be properly
across the fabric width. Bow and skew are more visually conditioned in a reasonable time with available facilities,
displeasing in colored, patterned fabrics such as plaids and perform the test without conditioning and report the actual
horizontal stripes rather than in solid colors because the condition prevailing at the time of the test. Such results may
contrast makes the distortion more prominent. These defects not correspond with the results obtained when testing condi-
may cause sewing problems in such fabrics and draping tioned specimens at the standard atmosphere for testing tex-
problems in finished products. In some cases, a specified tiles.
amount of skew is needed, for example, to prevent twisting of
pant legs made of twill fabric. Matching plaids from distorted
9. Procedure
patterns may create serious problems for the garment manu-
9.1 Test the test specimens in the standard atmosphere for
facturer or home sewer. Wavy or sharp breaks in the bow line
testing textiles in accordance with Section 8.
are more detrimental to the appearance of small parts of a
9.2 Handle the test specimens carefully to avoid altering the
garment (such as collars, pockets, and so forth) than a gradual
natural state of the material.
slope from a straight line.
5.3.1 Automotive interior textiles used for seat bolsters,
9.3 Lay the fabric on a smooth, horizontal surface without
cushions, headrests and door panels may be susceptible to bow
tension in any direction or use the optional fabric inspection
and skew, especially when visually patterned fabrics are joined
table.
or mated to a straight edge surface.
9.4 Bow:
9.4.1 Measure the bow in three places spaced as widely as
6. Apparatus
possible along the length of the fabric or along a minimum of
6.1 Measuring Stick or Steel Tape, graduated in 1-mm
1 m (1 yd). If possible, make no measurement closer to the
( ⁄16-in.) divisions and longer than the width of the fabric that
ends of the roll or piece of fabric than1m(1 yd).
is to be measured.
9.4.2 Follow a distinctive color yarn or pattern line across
the width of the fabric. Trace one filling yarn, knitting course,
6.2 Rigid Straightedge or t-square, longer than the width of
or printed line across the full width of the fabric using a soft
the fabric that is to be measured.
pencil or suitable marker.
6.3 Flat Surface, of sufficient length to unroll or unfold the
9.4.3 Place a rigid straightedge across the fabric connecting
fabric (see 6.4).
the points at which the distinctive color yarn or pattern line, or
6.4 Fabric Inspection Table (Optional), to unroll and roll
marked yarn meets the two selvages or edges.
fabric rolls or unfold and fold fabric bolts with sufficient
9.4.4 Measure the distance along the straightedge between
lighting that provides transmitted light from underneath the
the two selvages or edges to the nearest 1 mm ( ⁄16 in.) and
fabric to make the defect more clearly visible.
record as the baseline distance (BL).
9.4.4.1 Forcertainenduseswhereseveralnarrowpanelsare
7. Sampling and Test Specimens
sewn in a garment, it will be necessary to measure the bow
across a narrower distance than the total width of the fabric, for
7.1 Primary Sampling Unit—Consider rolls or bolts of
example, a width of 38 cm (15 in.).This distance is used as the
fabric or fabric components of fabricated systems to be the
fabric width when calculating the bow.
primary sampling unit, as applicable.
9.4.4.2 For automotive or other applications where narrow
7.2 Laboratory Sampling Unit—As a laboratory sampling
panels or cut pieces are used, it will be necessary to measure
unit take the entire roll or bolt after removing a first 1-mm
bowacrossanarrowerdistancethanacrossthefullwidthofthe
(1-yd)length.Forfabriccomponentsoffabricatedsystems,use
fabric, for example, a width of 400 mm (16 in.). Use this
the entire system.
distance as the fabric width when calculating bow.
7.3 Test Specimens—As test specimens, select 3 test areas
9.4.5 Measure the greatest distance parallel to the selvages
from each laboratory sampling unit. Exclude the first and last
oredgesbetweenthestraightedgeandthedistinctivecoloryarn
fifth of the roll or bolt or piece length. Select test areas at
orpatternline,ormarkedyarntothenearest1mm( ⁄16in.)and
random but no closer to one another than one fifth of the roll
record as the bow distance (D) including the type. (See Fig. 1).
or bolt or piece length.
9.4.5.1 If double bow is evident, measure and record both
7.3.1 Optical test specimens—Select 3 test areas from each
distances.
sampling unit. Exclude the first and last 10 m (11 yd) of a roll
NOTE 1—Fig. 1 represents typical examples of bows in a fabric that do
and test random areas within the roll.
not have any skew. Many variations in the shape or deepest portion of the
7.3.1.1 Cut pieces that are at least 400 mm (16 in.) in width
arc can occur in actual fabrics. No provision is made to measure bow in
can be measured for bow and skew.
the presence of s
...


This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation: D3882 − 08 (Reapproved 2012) D3882 − 08 (Reapproved 2016)
Standard Test Method for
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.
ε NOTE—The language in 9.5.2 and 9.5.5 was corrected editorially to match Fig. 2 in July 2012.
1. 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.
2. Referenced Documents
2.1 ASTM Standards:
D123 Terminology Relating to Textiles
D1776 Practice for Conditioning and Testing Textiles
D2904 Practice for Interlaboratory Testing of a Textile Test Method that Produces Normally Distributed Data (Withdrawn 2008)
D2906 Practice for Statements on Precision and Bias for Textiles (Withdrawn 2008)
D3990 Terminology Relating to Fabric Defects
3. Terminology
3.1 For all terminology related to Fabric Defects see Terminology D3990.
3.2 The following terms are relevant to this standard: bow, double bow, double hooked bow, double reverse bow, hooked bow,
knitted fabric, skew, standard atmosphere for testing textiles.
3.3 For definitions of all other textile terms see Terminology D123.
4. Summary of Test Method
4.1 Bow—A straightedge is placed across the fabric between two points at which a marked filling yarn, knitting course,
designated printed line, or designated design meets the two selvages or edges. The greatest distance between the straightedge and
the marked filling line, knitting course, designated printed line, or designated design is measured parallel to the selvage.
4.2 Skew—The straight-line distortion of a marked filling yarn, knitting course, designated printed line, or designated design is
measured from its normal perpendicular to the selvage or edge.
5. Significance and Use
5.1 This test method is considered satisfactory for acceptance testing of commercial shipments.
This test method is under the jurisdiction of ASTM Committee D13 on Textiles and is the direct responsibility of Subcommittee D13.60 on Fabric Test Methods, Specific.
Current edition approved July 1, 2012July 1, 2016. Published August 2012July 2016. Originally approved in 1980. Last previous edition approved in 20082012 as
ε1
D3882 – 08(2012) . DOI: 10.1520/D3882-08R12E01.10.1520/D3882-08R16.
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 the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3882 − 08 (2016)
5.1.1 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.
5.2 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.
5.3 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 the bow line are more
detrimental to the appearance of small parts of a garment (such as collars, pockets, and so forth) than a gradual slope from a straight
line.
5.3.1 Automotive interior textiles used for seat bolsters, cushions, headrests and door panels may be susceptible to bow and
skew, especially when visually patterned fabrics are joined or mated to a straight edge surface.
6. Apparatus
6.1 Measuring Stick or Steel Tape, graduated in 1-mm ( ⁄16-in.) divisions and longer than the width of the fabric that is to be
measured.
6.2 Rigid Straightedge or t-square, longer than the width of the fabric that is to be measured.
6.3 Flat Surface, of sufficient length to unroll or unfold the fabric (see 6.4).
6.4 Fabric Inspection Table (Optional), to unroll and roll fabric rolls or unfold and fold fabric bolts with sufficient lighting that
provides transmitted light from underneath the fabric to make the defect more clearly visible.
7. Sampling and Test Specimens
7.1 Primary Sampling Unit—Consider rolls or bolts of fabric or fabric components of fabricated systems to be the primary
sampling unit, as applicable.
7.2 Laboratory Sampling Unit—As a laboratory sampling unit take the entire roll or bolt after removing a first 1-mm (1-yd)
length. For fabric components of fabricated systems, use the entire system.
7.3 Test Specimens—As test specimens, select 3 test areas from each laboratory sampling unit. Exclude the first and last fifth
of the roll or bolt or piece length. Select test areas at random but no closer to one another than one fifth of the roll or bolt or piece
length.
7.3.1 Optical test specimens—Select 3 test areas from each sampling unit. Exclude the first and last 10 m (11 yd) of a roll and
test random areas within the roll.
7.3.1.1 Cut pieces that are at least 400 mm (16 in.) in width can be measured for bow and skew.
8. Conditioning
8.1 Condition the test specimens to moisture equilibrium for testing in the standard atmosphere for testing textiles in accordance
with Practice D1776 or, if applicable, in the specified atmosphere in which the testing is to be performed.
8.1.1 When full rolls or bolts of fabric cannot be properly conditioned in a reasonable time with available facilities, perform
the test without conditioning and report the actual condition prevailing at the time of the test. Such results may not correspond with
the results obtained when testing conditioned specimens at the standard atmosphere for testing textiles.
9. Procedure
9.1 Test the test specimens in the standard atmosphere for testing textiles in accordance with Section 8.
9.2 Handle the test specimens carefully to avoid altering the natural state of the material.
9.3 Lay the fabric on a smooth, horizontal surface without tension in any direction or use the optional fabric inspection table.
9.4 Bow:
9.4.1 Measure the bow in three places spaced as widely as possible along the length of the fabric or along a minimum of 1 m
(1 yd). If possible, make no measurement closer to the ends of the roll or piece of fabric than 1 m (1 yd).
D3882 − 08 (2016)
9.4.2 Follow a distinctive color yarn or pattern line across the width of the fabric. Trace one filling yarn, knitting course, or
printed line across the full width of the fabric using a soft pencil or suitable marker.
9.4.3 Place a rigid straightedge across the fabric connecting the points at which the distinctive color yarn or pattern line, or
marked yarn meets the two selvages or edges.
9.4.4 Measure the distance along the straightedge between the two selvages or edges to the nearest 1 mm ( ⁄16 in.) and record
as the baseline distance (BL).
9.4.4.1 For certain end uses where several narrow panels are sewn in a garment, it will be necessary to measure the bow across
a narrower distance than the total width of the fabric, for example, a width of 38 cm (15 in.). This distance is used as the fabric
width when calculating the bow.
9.4.4.2 For automotive or other applications where narrow panels or cut pieces are used, it will be necessary to measure bow
across a narrower distance than across the full width of the fabric, for example, a width of 400 mm (16 in.). Use this distance as
the fabric width when calculating bow.
9.4.5 Measure the greatest distance parallel to the selvages or edges between the straightedge and the distinctive color yarn or
pattern line, or marked yarn to the near
...

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