1、Designation: D 2970/D 2970M 04Standard Test Methods forTesting Tire Cords, Tire Cord Fabrics, and Industrial YarnsMade From Glass Filaments1This standard is issued under the fixed designation D 2970/D 2970M; the number immediately following the designation indicates theyear of original adoption or,
2、in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover the testing of industrial yarnsmade of glass filaments,
3、 cords twisted from such yarns, andfabric woven from such cordsproducts that are made spe-cifically for use in the manufacture of pneumatic tires. Byagreement, these test methods may be applied to similar glassyarns and cords used for reinforcing other rubber goods and forother industrial applicatio
4、ns. The yarn or cord may be woundon cones, tubes, bobbins, spools, or beams, woven into fabric,or in other forms. These test methods include testing proce-dures only. These test methods do not include specifications ortolerances.1.2 No procedure is included for the determination offatigue resistance
5、 of cords, but several articles relating to themeasurement of fatigue resistance of cords made from man-made filaments and cured in rubber were published in thebibliography of Test Methods D 885.1.3 The following sections are included:SectionAdhesion of Cords to Elastomers 24Breaking Strength (Force
6、) 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 Mo
7、dulus 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
8、 of Dipped Yarns and Cords 191.4 These test methods show the values in both SI units andin inch-pound units. “SI units” is the technically correct namefor the system of metric units known as the InternationalSystem of Units. “Inch-pound units” is the technically correctname for the customary units u
9、sed in the United States. Thevalues stated in either acceptable metric units or other unitsshall be regarded separately as standard. The values expressedin each system may not be exact equivalents; therefore, eachsystem must be used independently of each other withoutcombining values in any way.1.5
10、This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Docum
11、ents2.1 ASTM Standards:2D 76 Specification for Tensile Testing Machines for TextilesD 123 Terminology Relating to TextileD 578 Specification for Glass Fiber StrandsD 885 Methods for Tire Cords, Tire Cord Fabrics, andIndustrial Filament Yarns Made from ManufacturedOrganic-Base FibersD 1423 Test Metho
12、d for Twist in Yarns by the Direct-Counting MethodD 2258 Practice for Sampling Yarn for TestingD 4393 Test Method for Strap Peel Adhesion of ReinforcingCords or Fabrics to Rubber CompoundsD 4848 Terminology of Force, and Deformation Propertiesof TextilesD 6477 Terminology Relating to Tire Cord and F
13、abrics3. Terminology3.1 Definitions:3.1.1 For definitions of terms related to tire cord, bead wire,hose wire, and tire cord fabrics, refer to Terminology D 6477.1These test methods are under the jurisdiction of ASTM Committee D13 onTextiles and are the direct responsibility of Subcommittee D13.19 on
14、 Tire Cord andFabrics.Current edition approved Oct. 1, 2004. Published October 2004. Originallypublished as D 2970M 80. Discontinued November 1995 and reinstated asD 2970 95. Last previous edition D 2970/D 2970M 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM
15、Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.1.1 The following terms are
16、 relevant to this standard”catenary length, cord twist, dip, dip pickup, in textile cord orfabric, industrial yarn, standard atmosphere for testing textiles,tabby sample, tire cord, and tire cord fabric.3.1.2 For definitions of terms related to force and deforma-tion in textiles, refer to Terminolog
17、y D 4848.3.1.2.1 The following terms are relevant to this standard:breaking force, breaking tenacity, initial modulus, tensilestrength.3.1.3 For definitions of other terms related to textiles, referto Terminology D 123.3.1.3.1 The following terms are relevant to this standard:fabric3.2 Abbreviation:
18、3.2.1 CREconstant-rate-of-extension4. Summary of Test Methods, General4.1 A summary of the directions prescribed for the determi-nation of specific properties is stated in the appropriate sectionsof specific test methods or the referenced standard.5. Significance and Use5.1 The procedures in these t
19、est methods may be used forthe acceptance testing of commercial shipments, but caution isadvised because technicians may fail to get good agreementbetween results on certain yarns, cords, or fabrics. Compara-tive tests as directed in Section 5.1.1 may be advisable.5.1.1 If there are differences of p
20、ractical significance be-tween reported test results for two laboratories (or more),comparative tests should be performed to determine if there isa statistical bias between them, using competent statisticalassistance. As a minimum, test samples should be used that areas homogeneous as possible, that
21、 are drawn from the materialfrom which the disparate test results were obtained, and thatare randomly assigned in equal numbers to each laboratory fortesting. Other materials with established test values may beused for this purpose. The test results from the two laboratoriesshould be compared using
22、a statistical test for unpaired data, ata probability level chosen prior to the testing series. If a bias isfound, either its cause must be found and corrected, or futuretest results for that material must be adjusted in considerationof the known bias.5.2 The significance and use of particular prope
23、rties arediscussed in the appropriate sections of the specific testmethods.SAMPLING AND CONDITIONING6. Sampling of Yarn and Cord6.1 Lot SampleAs a lot sample for acceptance testing,take at random the number of shipping cases or beams directedin an applicable material specification or Practice D 2258
24、.Consider shipping cases to be the primary sampling unit.6.2 Laboratory Sample:6.2.1 Yarn or Cord in CasesAs a laboratory sample foracceptance testing, select packages at random from eachshipping case in the lot sample. Take the number of packagesfor the laboratory sample as directed in an applicabl
25、e materialspecification or Practice D 2258. Preferably, the same numberof packages should be taken from each shipping case in the lotsample. If differing numbers of packages are to be taken fromshipping cases in the lot sample, the cases from which aspecific number of packages are to be drawn should
26、 bedetermined at random.6.2.2 Yarn on BeamsAs a laboratory sample for accep-tance testing, select ends at random from each beam in the lotsample. Take the number of ends for the laboratory sample asdirected in an applicable material specification or PracticeD 2258. Wind the laboratory samples on a t
27、ube or spool usinga winder with a tension of 5 6 1 mN/tex (0.05 6 0.01 gf/den)using the general technique directed in Practice D 2258.6.2.2.1 Take laboratory samples from the outside of thebeams unless there is a question or disagreement about ashipment. In that case, take laboratory samples after r
28、emovinga radial depth of 6 mm (14 in.) or more to minimize the effectsof handling and atmospheric changes that occurred duringshipment or storage. Place the laboratory samples in a moistureresistant container to protect them from atmospheric changesuntil the yarn is conditioned in the atmosphere for
29、 testing tirecords and industrial yarns.6.3 Test SpecimensTake the number of specimens fromeach laboratory sampling unit as directed in each test method.6.3.1 Preparation of SpecimensUnwind and discard atleast six layers of yarn or cord from the package to eliminateultraviolet and physically damaged
30、 material (except frombeams). If specimens are not taken directly from the originalpackage, it is advisable to wind the sample on a tube or spoolby means of a winder using a tension of 5 6 1 mN/tex (0.05 60.01 gf/den). If the specimen is collected as a loosely woundpackage, or in the form of a skein
31、, report that the observedresults were determined on a relaxed sample. Use care inhandling the specimen. Discard any specimen subjected to anychange of twist, kinking or making any bend with a diameterless than 6 mm (14 in.). Place the specimen in a moistureresistant polyethylene bag or other moistu
32、re resistant containerto protect it from atmospheric changes until ready to conditionin the atmosphere for testing industrial yarns and tire cords.6.3.2 If the yarn or cord has been treated with a resorcinol-formaldehyde-latex (RFL) type adhesive, samples should beprotected against exposure to ultra
33、violet light, high humidity(over 60 % relative humidity) and high temperature (over 38C(100F).7. Sampling of Tire Cord Fabric7.1 Lot SampleAs a lot to be sampled for acceptancetesting, take tire cord fabric produced on only one loom creel.As a primary sampling unit, select one roll of fabric from th
34、elot and prepare tabby sample to yield the laboratory samplingunits as directed in Section 7.2.7.2 Preparation of Laboratory SampleTake a sampleequal to the length of cord between the regular tabby woven atthe end of the roll and a special tabby woven a short distancefrom the end when the roll of fa
35、bric is manufactured. For rollsthat do not have a special woven tabby, improvise a tabby bythe use of gummed tape or strips of cemented fabric appliedacross a section of the cord fabric. The length of the tabbysample shall be as agreed upon by the purchaser and thesupplier. The recommended minimum i
36、s 0.5 m (18 in.). TheD 2970/D 2970M 042width of the sample shall be at least one tenth of the roll width.Cut the warp cords of the fabric along the center line of thespecial tabby across for a distance equal to the width of therequired sample. If this distance is less than the full width ofthe fabri
37、c, cut the filling yarns of the sample and of the specialand regular tabbies in the direction parallel with the warpcords. The resulting section of cord fabric is the tabby sample.Attach the tabby sample to a piece of cardboard or fiber board,the length of which shall be equal to at least the length
38、 of thecord warp between tabbies. Fold the tabby portions of thesample over each end of the board, and secure the sample to theboard with pressure-sensitive tape or staples. Use care to avoidcontact of tape or staples with the area to be tested. Handle thesample carefully and hold it under sufficien
39、t tension in the warpdirection to prevent the cords from kinking. The board with thesample may be folded lengthwise and parallel with the warp forconvenience. Place the board with the fabric sample in apolyethylene bag, or wrap it with several layers of polyethyl-ene film to protect the sample from
40、changes in atmosphericmoisture content until ready to condition in the atmosphere fortesting industrial yarns and tire cords. Use care during subse-quent handling of the sample to prevent any change in the cordtwist and to avoid kinking of the cords in the area to be tested.7.3 Test SpecimensTake th
41、e number of specimens atrandom from each laboratory sampling unit as directed in eachof the specific test methods.8. Conditioning8.1 Bring all specimens of yarn, cord, and fabric to moistureequilibrium for testing in the atmosphere for testing industrialyarns and tire cords.TENSILE PROPERTIES OF YAR
42、NS AND CORDS9. Scope9.1 These tests are used to determine the tensile propertiesof yarns and cords.10. Summary of Test Method10.1 A continually increasing force is applied longitudinallyto a conditioned specimen of yarn or cord placed in the clampsof a tensile testing machine until broken. The break
43、ing forceand elongation are observed depending upon the option em-ployed. Two clamping options are provided: Option 1, drumclamp; and Option 2, pneumatically-operated clamps havingfixed snubbing surfaces that are integral with one of theclamping surfaces. Elongation and modulus are calculatedfrom th
44、e force-extension curve when using Option 2. Breakingtenacity is calculated using yarn number.11. Significance and Use11.1 In some laboratories, the output of the CRE-type oftensile testing machine may be connected with electronicrecording and computing equipment that may be programmedto calculate a
45、nd print the results of tests for each requiredproperty. Because of the variety of electronic equipmentavailable, and the various possibilities for recording test data,use of this type of equipment is not covered in this test method.11.2 The levels of tensile properties obtained when testingindustri
46、al yarns and tire cords are dependent to a certain extenton the age and history of the sample and on the specificconditions used during the test. Among these conditions arerate of tensioning, type of clamps, gage length of specimen,temperature and humidity of the atmosphere, rate of airflowacross th
47、e specimen, and temperature and moisture content ofthe specimen. Testing conditions accordingly are specifiedprecisely to give reproducible test results on a specific sample.11.3 Because the load-bearing ability of a reinforced rubberproduct is related to the strength of the yarn or cord used as are
48、inforcing material, breaking strength is used in engineeringcalculations when designing various types of textile reinforcedrubber products. When intrinsic strength characteristics ofyarns and cords of different sizes or different types of fiber areto be compared, breaking tenacity is very useful, be
49、cause formost types of fiber, breaking force is approximately propor-tional to linear density.11.4 The drum clamp option gives a more accurate measureof strength since it minimizes the effect of clamping and isrecommended when strength only is required. Elongation andmodulus are not readily measured by this option.11.5 The pneumatic-type clamp option provides for themeasurement of strength, elongation, and modulus. However,the strength of the yarn or cord may be lower and subject togreater variation due to the effect of clamping.11.6 Elongation of yarn or cord is t
