1、Designation: D 5591 04Standard Test Method forThermal Shrinkage Force of Yarn and Cord With a ThermalShrinkage Force Tester1This standard is issued under the fixed designation D 5591; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、 the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers preparation and procedures tomeasure the thermal shrinkage force of yarns and co
3、rds in air.1.2 This test method is applicable to measurement of thethermal shrinkage force of yarns and cords whose shrinkageforce at 180 6 2C (355 6 4F) in air does not exceed 20 N(4 lbf). This test method is applicable to nylon, polyester, andaramid yarns and cords within the applicable range of t
4、hermalshrinkage force, as well as to comparable yarns and cords fromother polymers.1.2.1 Test specimens may be taken from yarn or cordpackages, or retrieved from fabrics.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 T
5、his 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. Specific hazardssta
6、tements are given in Section 8.2. Referenced Documents2.1 ASTM Standards:2D 123 Terminology Relating to TextilesD 885 Methods for Tire Cords, Tire Cord Fabrics, andIndustrial Filament Yarns Made from ManufacturedOrganic-Base FibersD 2258 Practice for Sampling Yarn for TestingD 6477 Terminology Relat
7、ing to Tire Cord and Fabrics3. Terminology3.1 Definitions:3.1.1 For definitions of terms relating to tire cord, bead wire,hose wire, and tire cord fabrics, refer to Terminology D 6477.3.1.1.1 The following terms are relevant to this standard:adhesive-treated tire cord, cord, greige cord, greige tire
8、 cord,pneumatic tire, retraction, in yarns and cords, standard atmo-sphere for testing textiles, thermal shrinkage force, thermalshrinkage force tester, and tire.3.2 For definitions of other terms related to textiles, refer toTerminology D 123.3.2.1 The following terms are relevant to this standard:
9、yarn.4. Summary of Test Method4.1 A specified length of yarn or cord is conditioned in arelaxed state, mounted with a pretension of 5 6 1 mN/tex (0.056 0.01 gf/den), then exposed to dry heat at a temperature of180 6 2C (355 6 4F) for 120 6 5s.4.2 The shrinkage force induced in the specimen is readfr
10、om the tester.5. Significance and Use5.1 This test method may be used for the acceptance testingof commercial shipments of yarns and cords.5.1.1 If there are differences of practical significance be-tween reported test results for two laboratories (or more),comparative tests should be performed to d
11、etermine if there isa statistical bias between them, using competent statisticalassistance. As a minimum, test samples should be used that areas homogeneous as possible, that are drawn from the materialfrom which the disparate test results were obtained, and thatare randomly assigned in equal number
12、s 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 a statistical test for unpaired data, ata probability level chosen prior to the testing series. If a bias isfound, either its
13、cause must be found and corrected, or futuretest results for that material must be adjusted in considerationof the known bias.5.2 Experience shows that yarns or cords on would pack-ages, usually being under tension, exhibit a contraction inlength (and a resulting increase in linear density) whenremo
14、ved from the package and allowed to relax over a period1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.19 on Tire Cord and Fabrics.Current edition approved Oct. 1, 2004. Published October 2004. Originallypublished as D
15、 5591 95. Last previous edition D 5591 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM Int
16、ernational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.of time at room temperature. Consequently, it they are testedwithout being allowed to relax, they will register higherthermal shrinkage force values as the relaxation shrinkage willbe incorrectly included
17、 as the thermal shrinkage force.5.2.1 Retractive forces vary widely by polymer type, beingalmost nil within aramids and significant within most nylons.For example, the exposure of untensioned skeins of nylon yarnor cord to 95 to 100 % relative humidity at room temperaturefor two days and recondition
18、ing under standard laboratoryconditions will cause most of the length change that is possibleat room temperature to occur within a sample. This reductionin length is accompanied by some lowering of thermal shrink-age force.5.3 The thermal shrinkage force of nylon, polyester, andaramid fiber is relat
19、ed to the polymer of origin and itsmanipulation in processing. Thermal shrinkage force measure-ment can be used to control product uniformity.5.4 The level of thermal shrinkage force is critical in theusers subsequent operations, such as the drum-set (originallength of cord) required to build a tire
20、 of a particular size.5.5 The thermal shrinkage force is critical to the final shapeand size of fiber-reinforced articles. For example, thermalshrinkage force affects the final size of V-belts and their abilityto maintain tension during their operation.5.6 This test method is in agreement with the n
21、ominalprocedures of Methods D 885 for the determination of thermalshrinkage force in yarns and cords.5.6.1 Shrinkage force is measured while the specimen iswithin an oven at a specified temperature and after a specifiedlength of time.6. Interferences6.1 If the chamber in which the specimen is heated
22、 is openon three sides, air drafts can effectively shorten the length ofspecimen experiencing the prescribed temperature environ-ment. The results obtained without a shield are generally lowerthan those obtained with a shield.6.2 The accurate control of temperature at any prescribedsetting is of utm
23、ost importance. Differences between the setpoint temperature and the temperature experienced by thespecimen are a major cause of the bias of test results. Thetemperature that the specimen experiences may be checked byattaching a small calibrated thermocouple to a piece of cordand suspending it in th
24、e specimen position such that the tip ofthe thermocouple is in the center of the oven cavity. Thethermocouple must not touch the oven walls. Either correct anyset point/sample temperature bias or determine the proper setpoint to give the specified specimen temperature. An intralabo-ratory comparison
25、 is the preferred method to determinewhether a bias exists.6.3 The differences in the amount of pre-relaxation of yarnscan cause differences in thermal shrinkage force, as noted in5.2.1.6.4 Shrinkage force is a combination of pretension force andthe force that is developed in the specimen as a resul
26、t of thespecimen being heated.6.5 Shrinkage force can be affected by the pretension, thelength of specimen exposure, improper location of the speci-men within the oven, and oven-surface contact of any part ofthe specimen. Specimens that are spun, textured, or crimped(such as those removed from a fab
27、ric) may allow filaments tocome into contact with interior surfaces of the thermal shrink-age force oven. Such physical contact will cause inaccuratereadings of the thermal shrinkage force.7. Apparatus7.1 Thermal Shrinkage Oven, consisting of a specimenheating cavity capable of heating up to 250C (4
28、80F), a meansof accurately controlling the temperature of the cavity 6 2C(4F), and a means for measuring and displaying the shrinkageforce up to 0.1 N (0.02 lbf).7.2 Stopwatch or Time, capable of reading to 6 1.0 s.7.3 Clip-On Tensioning Masses.7.4 Draft Shield for Shrinkage Oven, if the oven does n
29、othave one provided.8. Hazards8.1 Do not touch the oven while it is in operation because itcan reach temperatures up to 200C (390F).8.2 Do not leave the oven unattended if a specimen isinstalled.9. Sampling9.1 Lot SampleAs a lot sample for acceptance testing,randomly select the number of shipping co
30、ntainers directed inan applicable material specification or other agreement be-tween the purchaser and the supplier. In the absence of such anagreement or material specification, proceed as directed inPractice D 2258. Consider shipping containers of yarn, cordand rolls of fabric to be the lot sampli
31、ng units.NOTE 1An adequate specification or other agreement between thepurchaser and the supplier requires taking into account the variabilitybetween shipping containers, between laboratory sampling units within ashipping container, and between test specimens within a laboratorysampling unit to prod
32、uce a sampling plan with a meaningful producersrisk, consumers risk, acceptable quality level, and limiting quality level.9.2 Laboratory SampleAs a laboratory sample for accep-tance testing, proceed as follows:9.2.1 For yarn or cord, take at random the number ofpackages per shipping container in the
33、 lot sample as directed inan applicable material specification or other agreement be-tween the purchaser and the supplier. In the absence of such anagreement or material specification, proceed as directed inPractice D 2258.9.2.2 For fabric, take a full-width swatch at least 1-m (1-yd)long from the o
34、utside of each roll of fabric in the lot sample,after first discarding all fabric from the outside of the rolls thatcontains creases, fold marks, disturbed weave, or contamina-tion by foreign material.9.3 Test Specimens:9.3.1 For yarns and cords, strip at least 50 m (55 yd) fromthe outside of each p
35、ackage in the laboratory sample. Inspectthe outside of the package after stripping off the yarn. If thereis visible damage, continue to strip off units of 50 m (55 yd)and reinspect until there is no visible damage. Take at leastthree specimens, 600-mm (24-in.) long, from each package inthe laborator
36、y sample. Discard and replace specimen lengthsthat are visibly damaged.D55910429.3.2 For tire cord fabrics, remove a minimum of fivelengths of warp yarn or cord 600-mm (24-in.) long from eachswatch in the laboratory sample, with the specimens beingtaken at least 75 mm (3 in.) from the selvage of the
37、 swatch. Forfabrics other than tire cord fabric, such as square-wovenfabrics, also take from each swatch in the laboratory sample aminimum of five lengths of filling yarn or cord 600-mm(24-in.) long after discarding those portions within 75 mm (3in.) of the selvage of the swatch.9.3.2.1 The instruct
38、ions on number of test specimens givenin 9.3.2 assume that the mean value of three thermal shrinkageforce results will characterize adequately the thermal shrinkageforce of the laboratory sample from which the specimens weretaken. The extra two specimens from fabric are taken to ensurethat a specime
39、n free of handling damage is available afterconditioning. If the applicable material specification or otheragreement between the purchaser and the supplier specifiestesting more than three specimens per laboratory sample, anadditional two specimens above the number specified shouldbe taken from the
40、laboratory sample and conditioned.9.4 Exercise caution that the specimens do not change twistin handling.10. Preparation of Apparatus10.1 Preheat the oven 45 min prior to testing with the draftshield covering the three open sides of the heating chamber.10.2 Test in the standard atmosphere for testin
41、g industrialyarns (see 3.1).10.3 Adjust the oven temperature controller set point to180C (355F).11. Conditioning11.1 Condition unrestrained specimens or segments of un-tensioned fabric in the atmosphere for testing industrial yarns(see 3.1). Ensure that no change in twist occurs while conduct-ing th
42、is procedure.11.1.1 Condition and relax the yarn and greige cord speci-mens 12 to 28 h.11.1.2 Condition and relax the adhesive-treated cordsamples 16 to 28 h, unless immediate testing (5 to 20 min afterprocessing) is agreed upon between the purchaser and thesupplier. Immediate testing must be report
43、ed as an exception tothis test method (see Section 13).12. Procedure12.1 For yarns or cords, use a pretension load of 5 6 1mN/tex (0.05 6 0.01 gf/den).12.2 Pull the specimen transport carriage assembly forwardagainst the front stops.12.3 Insert one end of the specimen through the open righthand clam
44、p and guide the end through to the opposite clampatop the load cell post.12.4 Zero the load cell.12.5 Close the right hand clamp, firmly securing the righthand end of the specimen.12.6 Apply the prescribed pretensioning mass to the freeend of the specimen (see Table 1) outside the left hand post.12.
45、7 Close the left hand clamp, securing the specimen atopthe load cell post.NOTE 2Take care that during the closing of the clamp on top of theload cell, the reading stays on zero.12.8 Remove the pretensioning mass.12.9 Push the carriage assembly back into the oven. Ensurethat the specimen is centered
46、in the oven and that no part of itis in contact with oven surfaces.12.10 Start the timer at the moment the carriage assembly isin the oven, if the apparatus does not have an automatic startfeature.12.11 At the end of 120 6 5 s, read the maximum shrinkageforce on the instrument scale to the nearest 0
47、1 N (0.02 lbf).12.12 Pull the carriage to the front and discard the speci-men.13. Report13.1 State that the specimens were tested as directed inD 5591. Describe the material(s) or product(s) tested and themethod of sampling used. Report the following information:13.1.1 Individual thermal shrinkage
48、force results as readfrom the indicator dial to the nearest tenth of a unit. Exercisecaution that the final shrinkage force is reported. Somecomputerized data printout options available may show theaverage force for a defined time interval.13.1.2 Pretension force used.13.1.3 Measurements as “immedia
49、te testing” if not condi-tioned for the standard period (see 11.1.1 and 11.1.2).13.1.4 Measurements as “package testing” if the specimenstaken from packages are not relaxed prior to testing.14. Precision and Bias14.1 Interlaboratory Test DataAn interlaboratory test wasrun in 1995 in which randomly drawn samples of threematerials, 1260/2 denier nylon cord, 1000/1 denier polyesteryarn, and 1500/2 denier polyester cord, were tested in each offive laboratories. Two operators in each laboratory tested threespecimens of each material on each of two days. For eachTABLE
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