iTeh StandardsiTeh Standards
EURUSD
Your shopping cart is empty.
ASTM

ASTM D2731-07

(Test Method)

Standard Test Method for Elastic Properties of Elastomeric Yarns (CRE Type Tensile Testing Machines)

Standard Test Method for Elastic Properties of Elastomeric Yarns (CRE Type Tensile Testing Machines)

SCOPE
p>1.1 This test method covers the determination of elastic properties of "as produced" elastomeric yarns made from rubber, spandex or other elastomers. Elastic properties include force at specified elongations, permanent deformation and stress decay. Other hysteresis related properties can be calculated.
For a method designed specifically for testing rubber threads, refer to Test Method D 2433.
1.2 This test method is not applicable to covered, wrapped, or core-spun yarns or yarns spun from elastomeric staple.
1.3 This test method is applicable to elastomeric yarns having a range of 40 to 3200 dtex (36 to 2900 denier).
1.4 The values stated in either SI units or U.S. Customary units are to be regarded separately as standard. Within the text, the U.S. Customary units are in parentheses. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other.
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.

General Information

Status
Historical
Publication Date
31-Dec-2006
ICS
59.080.20 - Yarns
Technical Committee
D13 - Textiles
Drafting Committee
D13.58 - Yarns and Fibers
Current Stage
Ref Project

Relations

Replaces
ASTM D2731-01 - Standard Test Method for Elastic Properties of Elastomeric Yarns (CRE Type Tensile Testing Machines)
Effective Date
01-Jan-2007
Replaced By
ASTM D2731-07(2012) - Standard Test Method for Elastic Properties of Elastomeric Yarns (CRE Type Tensile Testing Machines)
Effective Date
01-Jul-2012

Buy Standard

ASTM D2731-07 - Standard Test Method for Elastic Properties of Elastomeric Yarns (CRE Type Tensile Testing Machines)ASTM D2731-07 - Standard Test Method for Elastic Properties of Elastomeric Yarns (CRE Type Tensile Testing Machines)
PreviousNext
Standard
ASTM D2731-07 - Standard Test Method for Elastic Properties of Elastomeric Yarns (CRE Type Tensile Testing Machines)
English language
5 pages
sale 15% off
Preview
sale 15% off
Preview

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
Designation:D2731–07
Standard Test Method for
Elastic Properties of Elastomeric Yarns (CRE Type Tensile
1
Testing Machines)
This standard is issued under the fixed designation D2731; 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 D2591 Test Method for Linear Density of Elastomeric
Yarns (Short Length Specimens)
1.1 This test method covers the determination of elastic
D2653 Test Method for Tensile Properties of Elastomeric
properties of “as produced” elastomeric yarns made from
Yarns (CRE Type Tensile Testing Machines)
rubber, spandex or other elastomers. Elastic properties include
D4848 Terminology Related to Force, Deformation and
force at specified elongations, permanent deformation and
Related Properties of Textiles
stress decay. Other hysteresis related properties can be calcu-
D4849 Terminology Related to Yarns and Fibers
lated.
D6717 Test Method for Linear Density of Elastomeric
NOTE 1—For a method designed specifically for testing rubber threads,
Yarns (Skein Specimens)
refer to Test Method D2433.
3. Terminology
1.2 This test method is not applicable to covered, wrapped,
or core-spun yarns or yarns spun from elastomeric staple.
3.1 For all terminology relating to D13.58, Yarns and
1.3 This test method is applicable to elastomeric yarns
Fibers, refer to Terminology D4849.
having a range of 40 to 3200 dtex (36 to 2900 denier).
3.1.1 The following terms are relevant to this standard:
1.4 The values stated in either SI units or U.S. Customary
deformation, elastomeric yarn, elongation, force at specified
units are to be regarded separately as standard. Within the text,
elongation,lineardensity,permanentdeformation,stress,stress
the U.S. Customary units are in parentheses. The values stated
decay.
in each system are not exact equivalents; therefore, each
3.2 For definitions of other terms related to force and
system shall be used independently of the other.
deformation, refer to Terminology D4848. For all other terms
1.5 This standard does not purport to address all of the
related to textiles, refer to Terminology D123.
safety concerns, if any, associated with its use. It is the
4. Summary of Test Method
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 4.1 Aspecimen, mounted in a CRE-type tensile machine, is
bility of regulatory limitations prior to use.
initially subjected to a series of five loading/unloading cycles
in which the specimen is extended and relaxed between zero
2. Referenced Documents
and 75 % of the elongation at first filament break (FFB).
2
2.1 ASTM Standards:
During the fifth cycle, the specimen is held at the maximum
D76 Specification for Tensile Testing Machines for Textiles
extension point for 30 s, then unloaded to allow a return to its
D123 Terminology Relating to Textiles
original gage length position. The specimen is then subjected
D1776 Practice for Conditioning and Testing Textiles
to a sixth load/unload cycle.
D2258 Practice for Sampling Yarn for Testing
4.2 Force at specified elongations are calculated from the
D2433 Test Methods for Rubber Thread
force-elongation curve for the first and fifth loadings and for
thefifthunloading.Stressdecayiscalculatedonthefifthcycle.
Extension at a specified force is determined on the sixth
1
This test method is under the jurisdiction ofASTM Committee D13 onTextiles
loading and is used to calculate the permanent deformation.
and is the direct responsibility of Subcommittee D13.58 on Yarns and Fibers.
Current edition approved Jan. 1, 2007. Published January 2007. Originally
5. Significance and Use
approved in 1968. Discontinued 1979 and reinstated as D2731 – 01. Last previous
edition approved in 2001 as D2731–01. DOI: 10.1520/D2731-07.
5.1 This test method is considered satisfactory for accep-
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
tance testing of commercial shipments since current estimates
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
of between-laboratory precision are acceptable and the method
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. is used extensively in the trade for acceptance testing.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
D2731–07
5.1.1 If there are differences of practical significance be- 6.4 Computer or Microprocessor, interfaced, with auto-
tween reported test results for two laboratories (or more),
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.

This May Also Interest You

ASTM
ASTM D6611-23(Test Method)
Standard Test Method for Wet and Dry Yarn-on-Yarn Abrasion Resistance

SIGNIFICANCE AND USE
5.1 This test method is intended for testing dry and wet abrasion resistance of manufactured fiber yarns. This test method is useful for ropes intended for use in the marine environment and for knitted hoses for various applications. The test method has been used with yarns having linear densities ranging from 65 tex to 335 tex, but may be used with yarns outside these ranges.  
5.2 Yarn to yarn friction is known to have a significant influence on abrasion resistance. To determine the coefficient of friction, use Test Method D3412.  
5.3 Limited interlaboratory correlation testing has been conducted to date. Single-laboratory testing, in accordance with ASTM practices, has been conducted. Test results should be used with caution.  
5.4 This test method is intended to provide additional data for specific applications such as mentioned in 5.1 and is not intended for quality control or test reports.  
5.5 If there are differences of practical significance between reported test results for two or more laboratories, 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 used should be as homogeneous as possible, be drawn from the material from which the disparate test results were obtained and be randomly assigned in equal numbers to each laboratory for testing. Other materials with established test values may be used for this purpose. The test results from the two or more laboratories should be compared using a statistical test for unpaired data, at a probability level chosen prior to testing. 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.  
5.6 This test method is conducted at one or several applied tensions that may depend upon the yarn material and size. The number and magnitudes of applied tensions and the number of eight specimen sets generally are agreed up...
SCOPE
1.1 This test method describes the measurement of abrasion resistance properties for manufactured fiber yarns in dry and wet conditions.  
1.2 This test method applies to manufactured yarns used in rope and knitted hose making.  
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are provided for information only.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 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.

  • Standard
    7 pages
    English language
    sale 15% off
  • Standard
    7 pages
    English language
    sale 15% off
ASTM
ASTM D1059-17(2022)(Test Method)
Standard Test Method for Yarn Number Based on Short-Length Specimens

SIGNIFICANCE AND USE
5.1 This is a quick method used for the determination of the approximate yarn number of short-length specimens taken from packages or fabrics.  
5.2 Because any error present in the reported length of the specimen is multiplied many times when calculating the theoretical yarn number using Eq 2 or Eq 3, it is extremely important that the length be measured as precisely as practicable.  
5.3 For the analysis of fabrics, this test method is adequate for estimating the approximate yarn number of the yarn used to weave or knit the fabric, but the results obtained by this test method may not agree with the nominal yarn number of the yarns actually used to make the fabric because of the changes in the yarn number produced by the weaving or knitting operations, the finishing treatments, and the dissecting operations. This test method is suitable for the evaluation of yarns as they occur in the finished fabric, when that information is needed.  
5.4 The yarn number obtained from the lengths taken from packages should not be expected to agree exactly with the values obtained by the use of the more precise methods of determining the yarn number included in Test Method D1907. If a sufficient number of consecutive specimens were tested, however, a close agreement with Option 1 of Test Method D1907 can be expected.  
5.5 This test method is designed to measure the yarn number of the single yarns present as a component of a plied yarn and the yarn number of the original single yarns used to produce a high twist yarn for a crepe fabric.  
5.6 This test method is not recommended for acceptance testing because of the short lengths used. In some cases, the purchaser and the supplier may have to test a commercial shipment of one or more specific materials by the best available method, even though the method has not been recommended for acceptance testing of commercial shipments.  
5.6.1 In such a case, if there is disagreement arising from the differences in values reported by th...
SCOPE
1.1 This test method covers the determination of the yarn number of all types of cotton, woolen, worsted, and man-made fiber yarns taken from packages; or from any textile fabrics in which the yarns are intact and can be removed in measurable lengths. The test method is not applicable to yarns taken from napped or cut pile fabrics. Because this test method is based on short-length specimens, the results should only be considered as approximations of yarn number.
Note 1: For a more precise procedure for the determination of yarn number, refer to Test Method D1907.
Note 2: The following additional methods for the determination of yarn number have been approved for yarns made from specific fibers: Specification D541, D578, and D681.  
1.2 This test method is applicable to yarns which stretch less than 5 % when tension on yarn is increased from 0.25 to 0.75 cN/tex (0.25 to 0.75 gf/tex). By mutual agreement it may be adapted to yarns which stretch more than 5 % by use of tension lower than that specified in the method for elastomers or use of tension higher than that specified in the method to pull the crimp out of textured yarns.  
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 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) Co...

  • Standard
    6 pages
    English language
    sale 15% off
ASTM
ASTM D5344-22(Test Method)
Standard Test Method for Extension Force of Partially Oriented Yarn

SIGNIFICANCE AND USE
5.1 This test method is considered satisfactory for acceptance testing of commercial shipments because current estimates of between-laboratory precision are acceptable and the method is used extensively in the trade for acceptance testing.  
5.1.1 If there are differences or 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 are obtained, and are assigned randomly in equal numbers to each laboratory for testing. Other materials 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 Elapsed time between spinning and testing has a marked effect on the results of the draw tension test, especially during the first 24 h. Therefore, if tested within 24 h of spinning, specimens should be compared only if tested after the same elapsed time. No specimen should be tested within 4 h of spinning because the aging process is at its most rapid rate during this period, and the differences in rate due to fiber structure are most pronounced.  
5.3 The extension force of manufactured filament yarns is related to the alignment of the molecules in the yarn filaments, which influences the yarn processing behavior. Knowledge of this property of partially oriented yarn is useful to determine processing conditions.
SCOPE
1.1 This test method covers the measurement of extension force developed while drawing a partially oriented filament yarn between pairs of draw rolls of different surface speeds.  
1.2 Extension force provides an estimate of the yarn orientation.  
1.3 This test method applies to partially oriented filament yarns less than 33.3 tex (300 denier), but it can be used for higher deniers by applying the test conditions as directed in Appendix X1.  
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are provided for information only.  
1.5 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.  
1.6 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.

  • Standard
    6 pages
    English language
    sale 15% off
  • Standard
    6 pages
    English language
    sale 15% off
ASTM
ASTM D4974/D4974M-22(Test Method)
Standard Test Method for Hot Air Thermal Shrinkage of Yarn and Cord Using a Thermal Shrinkage Oven

SIGNIFICANCE AND USE
5.1 This test method may be used for the acceptance testing of commercial shipments of yarns and cords. Caution is advised because yarn and cord may contract in length over a period of time due to room temperature retraction. Thermal shrinkage values are reduced proportionately by the amount of room temperature retraction.
Note 1: Experience, especially with nylon, shows that yarn retraction, which may be observed directly as shortening of length (or indirectly as denier increase), will occur in unrestrained yarn or cord that is not at equilibrium (equilibrium in this case being defined as essentially zero thermal shrinkage yarn or fully relaxed yarn). Normally, retractive forces are present in most wound packages of yarn and cord; thus, unrestrained yarn near the surface is likely, with time, to undergo some retraction. After retraction, such yarns exhibit lower thermal shrinkage values than yarn or cord deeper within the package. The opposite condition of yarn on the surface exists with yarn or cord wound against or near a rigid package core, such as a metal or hardwood wind-up spool. Such core yarn or cord cannot move against this restraint, and thus, will exhibit thermal shrinkage values even several weeks later near to those which were measured immediately from the surface of the freshly wound package. Elevated humidity will accelerate retraction of unrestrained yarn, but moisture content in itself will have little influence on thermal shrinkage. Exposure of untensioned skeins of yarn or cord to 95 to 100 % relative humidity at room temperature for two days and reconditioning under standard laboratory conditions will cause most of the room temperature retraction that is possible within a sample to occur.  
5.1.1 In case of differences of practical significance in reported test results from two or more laboratories conduct comparative tests to determine if there is a statistical bias between them. Competent statistical assistance is recommended for the invest...
SCOPE
1.1 This test method covers the measurement of shrinkage of yarns and cords when exposed in a thermal shrinkage oven.  
1.2 This test method is applicable to yarns and cords made of nylon, polyester, and other polymers not detrimentally affected by the temperature used and with linear densities in the range from 20 to 700 tex [180 to 6300 denier].  
1.2.1 Yarns or cords for testing may be taken from yarn or cord packages or from fabrics.  
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 are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. Referee decisions are to use SI units.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific hazard statements are given in Section 8.  
1.5 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.

  • Standard
    7 pages
    English language
    sale 15% off
  • Standard
    7 pages
    English language
    sale 15% off
ASTM
ASTM D6774-22(Test Method)
Standard Test Method for Crimp and Shrinkage Properties for Textured Yarns Using a Dynamic Textured Yarn Tester

SIGNIFICANCE AND USE
5.1 Test Method D6774, for determining maximum total contraction, crimp, and residual fiber shrinkage in textured filament yarns is suitable 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, use the samples for such a comparative tests that are as homogeneous as possible, drawn from the same lot of material as the samples that resulted in disparate results during initial testing and randomly assigned in equal numbers to each laboratory. The test results from the laboratories involved should be compared using a statistical test for unpaired data, 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 properties and their variability as measured by this method relate to bulk appearance, stretch and recovery of fabrics and dyeability of yarns.  
5.3 For some yarns, elapsed time between processing and testing has a marked effect on the results, of this test, especially during the first 72 h. The effect is caused by stress decay which is known to be minimal beyond the seventh day and after which time the yarn remains relatively stable. Therefore, specimens should only be compared if tested after the same elapsed time. Samples can be tested at-line, thus having little to no elapsed time between processing and testing.
SCOPE
1.1 This test method covers the determination of crimp contraction, residual fiber shrinkage and their variability of all types of filament yarns (partially oriented yarn (POY), fully oriented yarn (FOY), flat yarns, textured and bulked continuous filament (BCF) carpet yarns) using an automated tester.
Note 1: For another method of testing crimp in textured yarns, refer to Test Method D4031.  
1.1.1 This method may also be used for non-textured yarns.  
1.2 This test method is limited to crimped, multi-filament yarns ranging from 22.0 dtex to 890 dtex (15 denier to 800 denier) and for BCF yarns from 890 dtex to 4200 dtex (800 denier to 3800 denier).  
1.3 The values stated in SI units are to be regarded as standard. Inch-pound units in parentheses after SI units are provided for information only and are not considered 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 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.

  • Standard
    6 pages
    English language
    sale 15% off
ASTM
ASTM D6612-00(2022)(Test Method)
Standard Test Method for Yarn Number and Yarn Number Variability Using Automated Tester

SIGNIFICANCE AND USE
5.1 Test Method D6612 for yarn number and yarn number variability is satisfactory for acceptance of commercial shipments and is used in the trade.  
5.1.1 If there are differences of practical significance between the reported test results for two or more laboratories, comparative tests should be performed by those laboratories to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum, samples used for each comparative tests should be as homogeneous as possible, drawn from the same lot of material as the samples that results in disparate results during initial testing, and randomly assigned in equal numbers to each laboratory. Other fabrics with established tests values are used for this purpose. The test results from the laboratories involved should be compared appropriate statistical analysis and a probability level chosen by the two parties before testing begins, 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 adjusted in consideration of the known bias.  
5.1.2 The average results from the two laboratories should be compared using appropriate statistical analysis and a probability level chosen by the two parties before the testing is begun. If a bias is found, either its cause must be found and corrected or the purchaser and the supplier must agree to interpret future test results with consideration to the known bias.  
5.2 Test Method D6612 also is used for the quality control of filament yarns.  
5.3 Indices of Variability:  
5.3.1 Coefficient of Variation—%CV is a standard statistical calculation and is the most common index of yarn unevenness. For most textile applications in the 80 to 330 dtex (70 to 300 denier) range, a 1.0 to 1.3 %CV is adequate. %CV of yarns coarser than 666 dtex (600 denier) is not routine and usually not meaningful. %CV is less discriminating that %DS.  
5.3.2 Bad/Good Test—%BGT...
SCOPE
1.1 This test method covers the measurement of yarn number up to 4000 dtex (3600 denier) and related variability properties of filament and spun yarns using an automated tester with capability for measuring mass variability characteristics.  
1.2 Yarn number variability properties include percent density spread (%DS), coefficient of variation (%CV), density frequency variation.  
Note 1: For determination of yarn number by use of reel and balance, refer to Test Method D1907. For another method of measuring variability (unevenness) in yarn, refer to Test Method D1425.  
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 are not necessarily exact equivalents; therefore to ensure conformance with this standard, each system shall be used independently of the other, and values from the two systems shall not be combined.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 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.

  • Standard
    4 pages
    English language
    sale 15% off
ASTM
ASTM D1423/D1423M-16(2022)(Test Method)
Standard Test Method for Twist in Yarns by Direct-Counting

SIGNIFICANCE AND USE
5.1 Test Method D1423 for testing twist in yarns by direct-counting is considered satisfactory for acceptance testing of commercial shipments because current estimates of between-laboratory precision are acceptable and the method has been used extensively in the trade for acceptance testing.  
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 use the samples for such comparative tests as homogeneous as possible, drawn from the same lot of material that resulted in the disparate test results and randomly in equal numbers to each laboratory. The test results from the laboratories involved 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 for that material must be adjusted in consideration of the known bias.  
5.2 The determination of twist in a straight section of a yarn is not the simple straightforward operation it appears to be, for the test results may be greatly influenced by variations in test procedures and techniques. In all manipulations, extreme care is necessary to prevent specimen rotation altering the twist level before testing begins.  
5.3 The twist in a yarn before it is packaged may be different from that of the yarn after it has been withdrawn from the package because of changes in tension and the effect of the method of withdrawal. If the yarn is withdrawn over-end, a slight increase or decrease in twist will take place, depending upon the direction of the twist in the yarn, the direction of winding on the package, and the length of the wrap on the package.  
5.4 When a yarn is incorporated into or removed from a more complex structure, alterations may occur as a result of ...
SCOPE
1.1 This test method covers the determination of the amount and direction of twist at the completion of any stage of twisting in single (spun or filament), plied, cabled, or novelty (exclusive of long-term repeat patterns) yarns. The procedures are designed primarily for yarns in packages, but, with special precautions, they are applicable to yarns taken from fabrics. The procedure for spun yarn in 9.2 is also applicable to rovings.  
1.2 For plied yarns, this test method covers the determination of the twist of the plied yarns and the twist of the single yarn before plying. For cabled yarns, the test method covers the determination of the cable or hawser twist; the twist of the plied yarn after plying, but prior to the last twisting operation; and the twist of the single yarn before plying. Procedures are also included for the determination of the twists of the single and plied yarn components as they lie in the final structure. Also, directions are included for the determination of twist in plied yarn made with direct cabling technology.  
1.3 This test method is not intended for yarns that extend more than 5.0 % when tension is increased from 2.5 to 7.5 mN/tex [0.25 to 0.75 gf/tex]. Following the procedures of this test method for such yarns would be independent of the bias and precision determined for this test method. The report from such testing should include the tension used for this testing.  
1.4 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.
Note 1: For a more rapid but less accurate method of determining twist in single spun yarns, refer to Test Method D1422.
Note 2: This test method has been evaluated for use in de...

  • Standard
    7 pages
    English language
    sale 15% off
ASTM
ASTM D2258/D2258M-16(2022)(Practice)
Standard Practice for Sampling Yarn for Testing

SIGNIFICANCE AND USE
5.1 Assigning a value to any property of the material in a container or in a lot, consignment, or delivery involves a measurement process that includes both sampling and testing procedures. The correctness of the value assigned depends upon the variability due to testing and sampling plan. Even when the variability due to testing is minimized by carefully developed procedures, correct and consistent estimates of the true value of the property are possible only when the sampling procedure avoids systematic bias, minimizes variations due to sampling, and provides a laboratory sample of adequate size.  
5.2 Practice D2258 may not give the most efficient sampling plan that might be devised in special situations but does present a general procedure that gives satisfactory precision with an economical amount of sampling. Many plans that include stratified sampling can be found in textbooks and through the use of statistical software tools and calculators.  
5.2.1 If not specified by the purchaser, the manufacturer will define suitable production lots based on one or more of the following: supply lot, production shift/time segment, production equipment or production line, operator, designated shipment, production run, or a combination herein.  
5.2.2 If not specified by the purchaser, the manufacturer will define sampling and testing frequency based on the following: process capability or capability analysis, historical trends, level of detection rate required, confidence level requirements, known variations or special causes, or both. Every attempt to ensure conforming product is being produced, identify potential nonconforming product or proper isolation and identification, will be carried out by the manufacturer.  
5.2.3 Sampling count and number of specimens will be based on standard practice listed within the document. Increase or decrease in count or frequency might be applied based on typical standard deviation, precision and confidence level, Measurement System...
SCOPE
1.1 This practice describes a procedure for the division of shipments of yarn into test lots and the sampling of such lots for testing.  
1.1.1 This practice can be used for lot sample testing of yarns for both pre-fabric production and post-fabric production.  
1.2 This practice is applicable to single, plied, or cabled yarns, and cords, made of any fiber or mixture of fibers, and supported on any form of package, including beams.  
1.3 This practice also describes procedures for the sampling of yarn(s) removed from woven or knitted fabrics; however, when thus sampled, the yarns are usually not representative of entire shipments, as referred to in 1.1. Consequently, the resultant sampling can only be used to determine the characteristics of the yarn and is usually not used for acceptance testing. Moreover, it should be recognized that the characteristics of yarns from fabrics may be different than the characteristics of the same yarn(s), prior to being entered into the fabric manufacturing process.  
1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.  
1.5 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.  
1.6 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...

  • Standard
    4 pages
    English language
    sale 15% off
ASTM
ASTM D3693-02(2021)(Specification)
Standard Specification for Labeled Length per Holder of Sewing Thread

ABSTRACT
This specification covers the requirements for the labeled lengths per holder of sewing threads of all materials. The test specimen is a thread holder whether a cone, tube, spool, ready-made bobbin, or any other holders. The observed length for all holders such as home sewing spools, ready-made bobbins, or all other holders which depends on the sampling size shall equal or exceed a certain percentage of the minimum allowable labeled length.
SCOPE
1.1 This specification covers requirements for the labeled lengths of sewing threads of all materials.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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.

  • Technical specification
    2 pages
    English language
    sale 15% off
ASTM
ASTM D2731-21(Test Method)
Standard Test Method for Elastic Properties of Elastomeric Yarns (CRE Type Tensile Testing Machines)

SIGNIFICANCE AND USE
5.1 This test method is considered satisfactory for acceptance testing of commercial shipments since current estimates of between-laboratory precision are acceptable and the method is used extensively in the trade for acceptance testing.  
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, use samples for such comparative tests that are as homogeneous as possible, drawn from the same lot of material as the samples that resulted in disparate results during initial testing, and randomly assigned in equal numbers to each laboratory. The test results from the laboratories involved should be compared using a statistical test for unpaired data, at a probability level chosen prior to the testing series. If 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 Force at Specified Elongation (FASE) is a measure of the tensile force occurring while extending a textile material within specified limits. This characteristic of elastomeric yarn indicates the resistance that will have to be overcome by the wearer while putting on a garment made of the material and is also an indication of the garment's resistance to deformation caused by normal body movements during wear. The elongations used for these measurements are typically 100 %, 200 % and 300 %.  
5.3 Permanent Deformation (set) is a measure of the increase in length of an elastomeric yarn resulting from cyclic stretching and relaxation. The characteristic is a visible indication of the realignment of intermolecular bonds within the elastic material. As with stress decay, the amount of set increases with yarn extension; however, for any particular extension, little or no additional set takes place after...
SCOPE
1.1 This test method covers the determination of elastic properties of “as produced” elastomeric yarns made from rubber, spandex or other elastomers. Elastic properties include force at specified elongations, permanent deformation and stress decay. Other hysteresis related properties can be calculated.
Note 1: For a method designed specifically for testing rubber threads, refer to Test Method D2433.  
1.2 This test method is not applicable to covered, wrapped, or core-spun yarns or yarns spun from elastomeric staple.  
1.3 This test method is applicable to elastomeric yarns having a range of 40 to 3200 dtex (36 to 2900 denier).  
1.4 The values stated in either SI units or U.S. Customary units are to be regarded separately as standard. Within the text, the U.S. Customary units are in parentheses. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other.  
1.5 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.  
1.6 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.

  • Standard
    6 pages
    English language
    sale 15% off
  • Standard
    6 pages
    English language
    sale 15% off