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4.1 The tex system has been approved for general use by the International Organization for Standardization, Technical Committee 38 on Textiles (ISO/TC 38), which has also recommended a list of rounded tex numbers for use with fibers and all types of yarns. Conversion tables showing the rounded tex numbers corresponding to various numbers in different traditional systems are given in Tables D2260 and ISO 2947.4.2 The tex system for designation of the linear density of fibers and yarns is a direct system based on mass per unit length, M/L, and employs metric units of length and mass. The tex unit, grams per kilometre (1000 m) has been approved by ISO/TC 38 for use with all fibers and all types of yarn. The committee has also approved the use of kilotex and decatex numbers for coarse structures and decitex and millitex numbers for fibers.4.3 The tex system relates to the property commonly associated with coarseness, or inverse fineness of a yarn because the tex numbers increase with an increase in the size or mass per unit length of the yarn. The tex system is intended for use by all branches of the textile industry, in all countries, for yarns made from all types of fibers or mixtures of fibers.1.1 This practice covers the use of the tex system to designate the linear density (number, or count) of fibers and of yarns made from any type of fiber or combination of fibers. It is also applicable to other textile materials, including yarn intermediates (slivers, rovings, tops, and so forth), single or plied yarns, cords, and threads.NOTE 1: The mass per unit length concept of linear density is applicable to any material which has a high ratio of length to cross section.1.2 Conversion factors for various indirect and direct yarn numbers to exact tex equivalents can be found in Standard Tables D2260.1.3 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.1.4 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.

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This specification covers the requirements for insect screening and louver cloth made from vinyl-coated glass yarns. Specifically covered here are: commercial standard vinyl-coated glass yarn insect screening designed and woven primarily for installation in or on any dwelling, patio, screening enclosure, building, or structure for the purpose of keeping out flies, mosquitoes, and most insects; and vinyl-coated glass yarn louver cloth used extensively in soffit and louver vents to keep out most large insects, birds, and airborne litter, while at the same time providing for adequate ventilation and air circulation. Products are produced in two basic classes (Classes 1 and 2) based on nominal thickness. Products shall be suitably tested and conform accordingly to specified requirements in tems of appearance, mesh, roll length, mass per unit area, flame resistance, fabric stability, bursting strength, stiffness index, and color stability to accelerated weathering.1.1 This specification covers the requirements for vinyl-coated glass yarn insect screening and louver cloth.1.2 This specification is intended to assist ultimate users by designating the sizes and types of these products that are generally available in the industry.1.3 This specification shows the terminology and requirements for:1.3.1 Commercial standard vinyl-coated glass yarn insect screening designed and woven primarily for installation in or on any dwelling, patio, screening enclosure, building, or structure for the purpose of keeping out flies, mosquitoes, and most insects.1.3.2 Vinyl-coated glass yarn louver cloth used extensively in soffit and louver vents to keep out most large insects, birds, and airborne litter, while at the same time providing for adequate ventilation and air circulation.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 The following precautionary caveat pertains only to the test methods portions, Sections 8 – 19, of this specification. 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.

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ASTM D299/D299M-04(2017) Standard Specification for Asbestos Yarns (Withdrawn 2022) Withdrawn, No replacement 发布日期 :  1970-01-01 实施日期 : 

This specification covers asbestos yarns having a specified minimum % mass of asbestos fiber, excluding the mass of other inorganic reinforcing strands which may be present. Asbestos yarns covered here are classified based on their structural component as follows: Class A, yarn consisting of asbestos fiber or asbestos and other fibers; Class B, yarn containing wire reinforcements; Class C, yarn containing organic reinforcing strands; Class D, yarn containing nonmetallic inorganic reinforcing strands; and Class E, yarn containing a combination of the reinforcing strands used in Classes B through D. On the other hand, the grades (Commercial, Underwriters', A, AA, AAA, and AAAA) of asbestos yarn are based on the percentage of asbestos content by mass. Yarns shall be sampled, prepared, tested and conform accordingly to physical (asbestos and reinforcement type and content), electromagnetic (magnetic rating and electrical insulation), mechanical (tensile or breaking strength), and dimensional (yarn number, twist direction, and number of turns per unit length) property requirements.1.1 This specification covers asbestos yarns having a minimum of 75  % asbestos fiber by mass, excluding the mass of other inorganic reinforcing strands which may be present.1.2 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.1.3 Warning—Breathing of asbestos dust is hazardous. Asbestos and asbestos products present demonstrated health risks for users and for those with whom they come into contact. In addition to other precautions, when working with asbestos-cement products, minimize the dust that results. For information on the safe use of chrysoltile asbestos, refer to “Safe Use of Chrysotile Asbestos: A Manual on Preventive and Control Measures.”21.4 The following safety hazards caveat pertains only to the test methods, Section 13, described in this specification: 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. See 1.3 for a specific safety hazard statement.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.

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5.1 This test method is used for acceptance testing in the trade for economic reasons even though it is less accurate than the direct method, Test Method D1423.5.1.1 If there are differences or practical significance between reported test results for two laboratories (or more), comparative tests should be performed to determine if their is a statistical bias between them, using competent statistical assistance. As a minimum, the test samples should be used that are as homogeneous as possible, that are drawn from the material from which the disparate test results are obtained, and that 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 The “setting” of twist in some fibers causes excessive contraction when the yarn is retwisted in the reverse direction. Therefore, the number of turns required to bring the specimen back to its original length may be less than the number of turns removed in untwisting. This effect may be partially offset by the use of higher pretensioning loads; but this increases the danger of stretching the yarn. Little information is available on the correct tensions to use for yarns made from different fibers or with different amounts of twist.5.3 In addition to being less tedious, this test method requires fewer specimens than the direct-counting method and the results may be sufficiently accurate for certain purposes. This test method can be useful in those cases where the main objective is to measure variations from an average value. Another possible application is where a large amount of twist testing is required on yarns of similar type and twist. In this case preliminary tests comparing this method and the direct method could be used to determine the correct pretension.5.4 Twist has important effects on the physical properties of yarn. Low-twist yarn is lofty and is usually preferred for knitting because of its softness, covering power, and warmth. Increasing the amount of twist causes an increase in yarn strength by increasing fiber cohesion, but as the twist angle increases beyond an optimum point, strength decreases due to a loss in effective fiber contribution. Maximum yarn strength is obtained by inserting a medium amount of twist to obtain an optimum balance between these two opposing forces. High twist produces yarns of high density (“hard” or “wiry”) and high elongation and may improve the abrasion and impact resistance of fabrics.5.5 The optimum twist for either manufacturing efficiency or physical properties usually increases as staple length decreases.5.6 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. Withdraw the yarn from the package in the direction of normal use, either from the side or over-end. 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 turn (or wrap) on the package.NOTE 2: The difference in twist between unwinding from the side and over-end is 1/πd, where d is the diameter of the package.4 Thus, for a 25-mm [1-in.] diameter package, the difference would be about 13 tpm or about one third tpi.5.7 When a yarn is taken from a more complex yarn structure or from a fabric, the resultant twist should be considered only an approximation of the original value because of alterations that may have occurred as a result of the effects of unwinding, handling, and mechanical strains met in processing.1.1 This test method2 describes the determination of twist in single spun yarns when only an approximation of the true twist is required.NOTE 1: For a more accurate method see Test Method D1423.1.2 This test method is applicable to spun single yarns in continuous lengths, and also to spun yarns raveled from fabrics, provided specimens at least 200 mm [8 in.] long can be obtained.1.3 This test method has been found satisfactory for use in determining the approximate twist content in single ring spun yarns of all types and fiber contents, but not in open-end spun yarns.1.4 This specification shows the values in both inch-pound units and SI units. The “inch-pound” units is the technically correct name for the customary units used in the United States. The “SI” units is the technically corrected name for the system of metric units known as the International System of 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.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.

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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 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 Linear density of elastomeric yarns is used in some calculations for tensile and elastic properties.5.3 The test method is based on elastomeric yarns in lthe “as-produced” condition, but may be used for treated elastomeric yarns provided the treatment is specified. The method does not cover the removal of finish for the determination of linear density of “finish-free” elastomeric yarns.1.1 This test method covers the determination of the linear density of short lengths of “as produced” elastomeric yarns made from rubber, spandex or other elastomers.NOTE 1: For the determination of linear density of elastomeric yarns using skeins, refer to Test Method D6717.1.2 This test method is not applicable to covered, wrapped, or core-spun yarns, or yarns spun from elastomeric staple, or elastomeric yarns removed from fabrics.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 test the US 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.

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5.1 The procedures in these test methods may be used for the acceptance testing of commercial shipments, but caution is advised because technicians may fail to get good agreement between results on certain yarns, cords, or fabrics. Comparative tests as directed in Section 5.1.1 may be advisable.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, test samples should be used that are as homogeneous as possible, that are drawn from the material from which the disparate test results were obtained, and that are 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 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 for that material must be adjusted in consideration of the known bias.5.2 The significance and use of particular properties are discussed in the appropriate sections of the specific test methods.1.1 These test methods cover the testing of industrial yarns made of glass filaments, cords twisted from such yarns, and fabric woven from such cords—products that are made specifically for use in the manufacture of pneumatic tires. By agreement, these test methods may be applied to similar glass yarns and cords used for reinforcing other rubber goods and for other industrial applications. The yarn or cord may be wound on cones, tubes, bobbins, spools, or beams, woven into fabric, or in other forms. These test methods include testing procedures only. These test methods do not include specifications or tolerances.1.2 No procedure is included for the determination of fatigue resistance of cords, but several articles relating to the measurement of fatigue resistance of cords made from man-made filaments and cured in rubber were published in the bibliography of Test Methods D885.1.3 The following sections are included:  SectionAdhesion of Cords to Elastomers 24Breaking Strength (Force) of Conditioned Yarns and Cords 13Breaking Tenacity of Conditioned Yarns and Cords 14Catenary Length of Cords Appendix X1Conditioning 8Construction of Yarns and Cords 18Count of Tire Cord Fabric 22Dip Pick-Up (DPU) on Yarns and Cords 23Elongation at Break of Conditioned Yarns and Cords 15Initial Modulus of Conditioned Yarns and Cords 16Keywords 28Mass of Tire Cord Fabric 22Precision and Bias 25 – 27Sampling of Yarn and Cord 6Sampling of Tire Cord Fabric 7Tensile Properties of Yarns and Cords 9 – 17Terminology 3Thickness of Cords 21Twist in Yarns and Cords 20Width of Tire Cord Fabric 22Yarn Number of Dipped Yarns and Cords 191.4 These test methods show the values in both SI units and in inch-pound units. “SI units” is the technically correct name for the system of metric units known as the International System of Units. “Inch-pound units” is the technically correct name for the customary units used in the United States. The values stated in either acceptable metric units or other units shall be regarded separately as standard. The values expressed in each system may not be exact equivalents; therefore, each system must be used independently of each other without combining values in any way.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 and health practices and determine the applicability of regulatory limitations prior to use.

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1.1 These test methods cover the testing of industrial yarns made of glass filaments, cords twisted from such yarns, and fabric woven from such cords-products that are made specifically for use in the manufacture of pneumatic tires. By agreement, these test methods may be applied to similar glass yarns and cords used for reinforcing other rubber goods and for other industrial applications. The yarn or cord may be wound on cones, tubes, bobbins, spools, or beams, woven into fabric, or in other forms. These test methods include specifications or tolerances.1.2 No procedure is included for the determination of fatigue resistance of cords, but several articles relating to the measurement of fatigue resistance of cords made from man-made filaments and cured in rubber were published in the bibliography of Test Methods D 885.1.3 The following sections are included: Adhesion of Cords to Elastomers (24); Breaking Strength (Force) of Conditioned Yarns and Cords (13); Breaking Tenacity of Conditioned Yarns and Cords (14); Catenary Length of Cords (Appendix X1); Conditioning (8); Construction of Yarns and Cords (18); Count of Tire Cord Fabric (22); Dip Pick-Up (DPU) on Yarns and Cords (23); Elongation at Break of Conditioned Yarns and Cords (15); Initial Modulus of Conditioned Yarns and Cords (16); Keywords (28); Mass of Tire Cord Fabric (22); Precision and Bias (25-27); Sampling of Yarn and Cord (6); Sampling of Tire Cord Fabric (7); Tensile Properties of Yarns and Cords (9-17); Terminology (3); Thickness of Cords (21); Twist in Yarns and Cords (20); Width of Tire Cord Fabric (22); Yarn Number of Dipped Yarns and Cords (19).1.4 These test methods show the values in both SI units and in inch-pound units. "SI units" is the technically correct name for the system of metric units known as the International System of Units. "Inch-pound units" is the technically correct name for the customary units used in the United States. The values state in either acceptable metric units or other units shall be regarded separately as standard. The values expressed in each system may not be exact equivalents; therefore, each system must be used independently of each other without combining values in any way.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 and health practices and determine the applicability of regulatory limitations prior to use.

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6.1 This method is considered satisfactory for acceptance grading of commercial shipments because it has been used extensively in the trade for this purpose.6.1.1 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.6.2 The appearance of a woven or knitted fabric depends to a large extent on the smoothness, cleanliness, and general appearance of the yarns from which the fabric is manufactured. Instruments are available for the measurement of unevenness and for counting neps and other imperfections in yarn, but the values obtained from such tests are not easily integrated into an over-all expression for actual fabric appearance. Yarn appearance grading affords additional information which the manufacturer of woven or knitted goods may, through experience, correlate with the appearance to be expected in fabrics made from the yarns.1.1 This test method covers the grading of singles spun yarns for appearance.1.2 This test method does not apply to plied yarns.1.3 The values stated in either inch-pound or SI units are to be regarded separately as the standard. The values stated in each system are not exact equivalents, therefore, each system must 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.21.5 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.

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5.1 Acceptance Testing—Option A1 of Test Method D2256 is considered satisfactory for acceptance testing of commercial shipments because the test method has been used extensively in the trade for acceptance testing. However, this statement is not applicable to knot and loop breaking force tests, tests on wet specimens, tests on oven-dried specimens, or tests on specimens exposed to low or high temperatures and should be used with caution for acceptance testing because factual information on between-laboratory precision and bias is not available.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 Fundamental Properties—The breaking tenacity, calculated from the breaking force and the linear density, and the elongation are fundamental properties that are widely used to establish limitations on yarn processing or conversion and on their end-use applications. Initial modulus is a measure of the resistance of the yarn to extension at forces below the yield point. The chord modulus is used to estimate the resistance to imposed strain. The breaking toughness is a measure of the work necessary to break the yarn.5.3 Comparison to Skein Testing—The single-strand method gives a more accurate measure of breaking force present in the material than does the skein method and uses less material. The skein-breaking force is always lower than the sum of the breaking forces of the same number of ends broken individually.5.4 Applicability—Most yarns can be tested by this test method. Some modification of clamping techniques may be necessary for a given yarn depending upon its structure and composition. To prevent slippage in the clamps or damage as a result of being gripped in the clamps, special clamping adaptations may be necessary with high modulus yarns made from fibers such as glass or extended chain polyolefin. Specimen clamping may be modified as required at the discretion of the individual laboratory providing a representative force-elongation curve is obtained. In any event, the procedure described in this test method for obtaining tensile properties must be maintained.5.5 Breaking Strength—The breaking strength of a yarn influences the breaking strength of fabrics made from the yarn, although the breaking strength of a fabric also depends on its construction and may be affected by manufacturing operations.5.5.1 Because breaking strength for any fiber-type is approximately proportional to linear density, strands of different sizes can be compared by converting the observed breaking strength to breaking tenacity (centinewtons per tex, grams-force per tex, or grams-force per denier).5.6 Elongation—The elongation of a yarn has an influence on the manufacturing process and the products made. It provides an indication of the likely stretch behavior of garment areas such as knees, elbows, or other points of stress. It also provides design criteria for stretch behavior of yarns or cords used as reinforcement for items such as plastic products, hose, and tires.5.7 Force-Elongation Curve—Force-elongation curves permit the calculation of various values, not all of which are discussed in this test method, such as elongation at break, elongation at specified force, force at specified elongation, initial elastic modulus which is resistance to stretching, compliance which is ability to yield under stress, and is the reciprocal of the elastic modulus, and area under the curve, a measure of toughness, which is proportional to the work done.NOTE 3: Force-elongation curves can be converted to stress-strain curves if the force is converted to unit stress, such as to centinewtons per tex, or pounds per square inch, or pascals, or grams-force per tex, or grams-force per denier, and the elongation is based on change per unit length.5.8 Knot and Loop Breaking Force—The reduction in breaking force due to the presence of a knot or loop is considered a measure of the brittleness of the yarn. Elongation in knot or loop tests is not known to have any significance and is not usually reported.5.9 Rate of Operation—In general, the breaking force decreases slightly as time-to-break increases.5.9.1 Operation of CRT, CRE, and CRL tension testing machines at a constant time-to-break has been found to minimize differences in test results between the three types of tension testing machines. When tensile tests are performed at a fixed time-to-break, then reasonable agreement in breaking force has generally been found to exist between CRT and CRE tension testing machines.4 Consistent results are also obtained between different manufacturers of CRL tension testing machines when they are operated at the same time-to-break. The agreement is not necessarily good, however, between CRE or CRT tension testing machines on the one hand and CRL tension testing machines on the other even when they are all operated at the same time-to-break. The CRE-type tester is the preferred tension testing machine.5.9.2 This test method specifies an average time-to-break of 20 ± 3 s as recommended by Specification D76/D76M. It also provides for alternate speeds, such as 300 ± 10 mm [12 ± 0.5 in.]/min when using a 250-mm [10-in.] gauge length. See 9.2.5.9.3 The tolerance of ±3 s for the time-to-break is wide enough to permit convenient adjustment of the tension testing machine's rate of operation, and it is narrow enough to ensure good agreement between tests. The difference in breaking force between tests at 17 and 23 s will usually not exceed 1.5 % of the higher value.5.9.4 In case a tension testing machine is not capable of being operated at 20-s time-to-break, alternative rates of operation are included in this test method. These alternative rates may be used only by agreement between the parties concerned or when required in an applicable material specification.5.10 Tests on Wet Specimens—Tests on wet specimens are usually made only on yarns which show a loss of breaking force when wet or when exposed to high humidity, for example, yarns made from animal fibers and man-made fibers based on regenerated and modified cellulose. Wet tests are made on flax yarns to detect adulteration by failure to show a gain in breaking force.5.11 Tests on Oven-Dried Specimens and Specimens at High Temperatures—Tests on oven-dried specimens at standard or high temperatures are usually made only on yarns that will be used at high temperatures or will be used under very dry conditions which will affect the observed breaking force, for example, on rayon yarns intended for use in tire cords and yarns for other industrial purposes. Note that results obtained when testing oven-dried specimens at standard temperature will not necessarily agree with the results obtained when testing oven-dried yarns at high temperatures.5.12 Tests on Specimens at Low Temperatures—Tests on specimens exposed to low temperatures are usually made only on yarns that will be used at low temperatures, for example, yarns used in outerwear designed for cold climates or outer-space situations. Low-temperature tests are made on coated yarns used in the manufacture of materials used in outdoor applications, such as screening fabrics.1.1 This test method covers the determination of tensile properties of monofilament, multifilament, and spun yarns, either single, plied, or cabled with the exception of yarns that stretch more than 5.0 % when tension is increased from 0.05 to 1.0 cN/tex [0.5 to 1.0 gf/tex].1.2 This test method covers the measurement of breaking force and elongation of yarns and includes directions for the calculation of breaking tenacity, initial modulus, chord modulus, and breaking toughness.1.2.1 Options are included for the testing of specimens in: (A) straight, (B) knotted, and (C) looped form.1.2.2 Conditions of test are included for the testing of specimens that are: (1) conditioned air, (2) wet, not immersed, (3) wet, immersed, (4) oven-dried, (5) exposed to elevated temperature, or (6) exposed to low temperature.NOTE 1: Special methods for testing yarns made from specific fibers; namely, glass, flax, hemp, ramie, and kraft paper and for specific products; namely, tire cords and rope, have been published: Test Methods D885, and Specification D578.NOTE 2: For directions covering the determination of breaking force of yarn by the skein method refer to Test Method D1578.1.3 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, 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.

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ASTM D2259-21 Standard Test Method for Shrinkage of Yarns Active 发布日期 :  1970-01-01 实施日期 : 

5.1 Test Method D2259 for testing yarn for shrinkage in boiling water, saturated steam, dry heat, or solvents is considered satisfactory for acceptance testing of commercial shipments of yarn because the test method has been used extensively in the trade for that purpose.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 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 Results obtained by this test method can be used for the following purposes:5.2.1 As an aid in predicting the dimensional stability of fabrics to wet processing,5.2.2 As an aid in predicting the dimensional stability of fabrics during processing at elevated temperatures, and5.2.3 As a control measure in the manufacture of some types of fibers.5.3 The shrinkage medium to be used in the test depends on the requirements of the parties involved.5.4 The procedure for shrinkage in boiling water is described in Section 12, for shrinkage in dry heat in Section 13, for shrinkage in saturated steam in Section 14, and for shrinkage in solvents in Section 15. A 30-min exposure time is prescribed for boiling water. In exposure to dry heat, saturated steam, or solvents, the extent of change in the length of yarn is dependent upon the fiber type and upon the time and temperature of the exposure. Fiber types differ in their reaction to elevated temperature as well as the nature of the specific solvent, and prior fiber history can have a great influence upon the heat and solvent shrinkage of a yarn. Therefore, the time and temperature conditions to be used to determine dry heat or saturated steam shrinkage must be agreed upon for the particular product involved. In addition, time and temperature conditions, and solvent to be used must be agreed upon for solvent shrinkage determination for the particular product involved.1.1 This test method is used to determine the shrinkage of yarns in skein form when treated in boiling water, dry heat, saturated steam, or solvents. This test method is applicable to yarns made from any fiber or combination of fibers where the tex of the yarn is known or can be determined. This test method is not recommended for elastomeric yarns and those yarns that stretch more than 5 % under the tension loadings prescribed, although it has been used for the latter.NOTE 1: Procedures for determining yarn shrinkage and bulk properties of textured yarns are covered in Test Method D4031.1.2 This test method shows the values in both SI and inch-pound units. “SI” units is the technically correct name for the system of metric units known as the International System of Units. “Inch-pound” units is the technically correct name for the customary units used in the United States. The values stated in either SI units or in other units shall be regarded as standard. The values expressed in each system may not be exact equivalents; therefore each system must be used independently of the other without combining in any way.1.3 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.1.4 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.

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