ASTM D4120-07(2018)
(Test Method)Standard Test Method for Fiber Cohesion in Roving, Sliver, and Top in Dynamic Tests
Standard Test Method for Fiber Cohesion in Roving, Sliver, and Top in Dynamic Tests
SIGNIFICANCE AND USE
5.1 This test method for the determination of cohesion in sliver, roving, or top in dynamic tests may be used for the acceptance testing of commercial shipments but caution is advised since information on between-laboratory precision is lacking. Comparative tests as directed in 5.1.1 may be advisable.
5.1.1 If there are differences or practical significance between reported test results for two laboratories (or more), comparative test should be performed to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum, test samples that are as homogeneous as possible, drawn from the material from which the disparate test results were obtained, and randomly assigned in equal numbers to each laboratory for testing. The test results from the two laboratories should be compare 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 for that material must be adjusted in consideration of the known bias.
5.2 The cohesive forces overcome in continuous drafting of slivers, rovings, or tops are affected by surface lubricants and such fiber properties as linear density, surface configuration, fiber length, fiber crimp, and fiber-frictional characteristics.
5.2.1 The concept of drafting is one of the most important principles in the production of yarn from fibrous raw stock.
5.2.2 The values of force to maintain drafting determined by this method are induced by mechanical means similar to those used in textile processing.
5.2.3 The attenuation of textile fiber strands while in motion closely approximates actual textile processing conditions, and the relative values of force may be used to predict processing behaviors.
5.3 Fiber cohesion is affected by the alignment of fiber in the textile strand and strand compaction in addition to the factors listed in 5.2. Although fibers are more...
SCOPE
1.1 This test method describes the measurement of fiber cohesion as the dynamic cohesive force required to maintain drafting in rovings, slivers or tops when they are subjected to stress induced by passing between pairs of drafting rolls of different surface speeds. The cohesive force is converted to cohesive tenacity based on the linear density of the material.
Note 1: For static tests refer to Test Method D2612.
1.2 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.3 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.
General Information
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Standards Content (Sample)
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: D4120 − 07 (Reapproved 2018)
Standard Test Method for
Fiber Cohesion in Roving, Sliver, and Top in Dynamic Tests
This standard is issued under the fixed designation D4120; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D3333Practice for Sampling Manufactured Staple Fibers,
Sliver, or Tow for Testing
1.1 This test method describes the measurement of fiber
D4849Terminology Related to Yarns and Fibers
cohesion as the dynamic cohesive force required to maintain
drafting in rovings, slivers or tops when they are subjected to
3. Terminology
stress induced by passing between pairs of drafting rolls of
different surface speeds. The cohesive force is converted to 3.1 For all terminology relating to D13.58, Yarns and
cohesive tenacity based on the linear density of the material. Fibers, refer to Terminology D4849.
3.1.1 The following terms are relevant to this standard:
NOTE 1—For static tests refer to Test Method D2612.
cohesive force, fiber cohesion, roving, sliver, tenacity, top.
1.2 This standard does not purport to address all of the
3.2 For all other terms are related to textiles, refer to
safety concerns, if any, associated with its use. It is the
Terminology D123.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
4. Summary of Test Method
mine the applicability of regulatory limitations prior to use.
1.3 This international standard was developed in accor-
4.1 This test method provides an indication of the ability of
dance with internationally recognized principles on standard- fibers to hold together by measuring the force required to slide
ization established in the Decision on Principles for the
fibers in a direction parallel to their length. Specific lengths of
Development of International Standards, Guides and Recom- roving, sliver, or top are drafted between two pairs of rollers,
mendations issued by the World Trade Organization Technical
witheachpairmovingatadifferentperipheralspeed.Thedraft
Barriers to Trade (TBT) Committee. forces are recorded. Test specimens are then weighed and the
linear density calculated. Drafting tenacity, calculated as the
2. Referenced Documents
draft resisting force per unit linear density, is considered to be
a measure of the dynamic fiber cohesion.
2.1 ASTM Standards:
D123Terminology Relating to Textiles
5. Significance and Use
D519Test Method for Length of Fiber in Wool Top
D1440Test Method for Length and Length Distribution of
5.1 This test method for the determination of cohesion in
Cotton Fibers (Array Method)
sliver, roving, or top in dynamic tests may be used for the
D1447Test Method for Length and Length Uniformity of
acceptance testing of commercial shipments but caution is
Cotton Fibers by Photoelectric Measurement
advised since information on between-laboratory precision is
D1575Test Method for Fiber Length of Wool in Scoured
lacking. Comparative tests as directed in 5.1.1 may be advis-
Wool and in Card Sliver
able.
D1776Practice for Conditioning and Testing Textiles
5.1.1 If there are differences or practical significance be-
D2258Practice for Sampling Yarn for Testing
tween reported test results for two laboratories (or more),
D2612Test Method for Fiber Cohesion in Sliver and Top
comparativetestshouldbeperformedtodetermineifthereisa
(Static Tests)
statistical bias between them, using competent statistical assis-
tance.As a minimum, test samples that are as homogeneous as
possible,drawnfromthematerialfromwhichthedisparatetest
ThistestmethodisunderthejurisdictionofASTMCommitteeD13onTextiles
resultswereobtained,andrandomlyassignedinequalnumbers
and is the direct responsibility of Subcommittee D13.58 on Yarns and Fibers.
to each laboratory for testing. The test results from the two
Current edition approved July 1, 2018. Published August 2018. Originally
laboratories should be compare using a statistical test for
approved in 1982. Last previous edition approved in 2012 as D4120–07(2012).
DOI: 10.1520/D4120-07R18.
unpaired data, at a probability level chosen prior to the testing
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
series. If a bias is found either its cause must be found and
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
corrected, or future test results for that material must be
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. adjusted in consideration of the known bias.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4120 − 07 (2018)
within a shipping unit if applicable, and within specimens from a single
5.2 The cohesive forces overcome in continuous drafting of
package,endorotherlaboratorysamplingunittoprovideasamplingplan
slivers, rovings, or tops are affected by surface lubricants and
with a meaningful producer’s risk, consumer’s risk, acceptable quality
such fiber properties as linear density, surface configuration,
level, and limiting quantity level.
fiber length, fiber crimp, and fiber-frictional characteristics.
7.2 Laboratory Sample— —As a laboratory sample for
5.2.1 The concept of drafting is one of the most important
acceptance testing, take at random from each shipping con-
principles in the production of yarn from fibrous raw stock.
tainerinthelotsamplethenumberoflaboratorysamplingunits
5.2.2 Thevaluesofforcetomaintaindraftingdeterminedby
as directed in an applicable material specification or other
this method are induced by mechanical means similar to those
agreement between purchaser and supplier such as an agree-
used in textile processing.
ment to use Practice D3333 or Practice D2258. Preferably, the
5.2.3 Theattenuationoftextilefiberstrandswhileinmotion
same number of laboratory sampling units are taken from each
closely approximates actual textile processing conditions, and
shipping container in the lot sample. If differing numbers of
the relative values of force may be used to predict processing
laboratory sampling units are to be taken from shipping
behaviors.
containers in the lot sample, determine at random which
5.3 Fiber cohesion is affected by the alignment of fiber in
shippingcontainersaretohaveeachnumberoflaboratoryunits
the textile strand and strand compaction in addition to the
drawn.
factorslistedin5.2.Althoughfibersaremorenearlyalignedin
7.2.1 Eachlaboratorysamplingunitshouldbeatleast100m
drawsliverthanincardsliver,thedrawsliverismorecompact.
long.
Thus,foragivenproductionrun,thedraftingforcesarehigher
7.3 Test Specimens— —From each laboratory sampling
for draw sliver than for card sliver.
unit, take one specimen. If the standard deviation determined
5.4 In addition to the aforementioned effects on drafting
for the laboratory sample is more than a value agreed upon
forces, the direction of specimen movement through drafting
between the purchaser and supplier, continue testing one
rollers may give different drafting force. Fibers in slivers may
specimen from each unit in the laboratory sample until the
have hooks of varying severity at one or both ends. Passage
standarddevi
...
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