1、Designation: D5591 04 (Reapproved 2011)Standard Test Method forThermal Shrinkage Force of Yarn and Cord With a ThermalShrinkage Force Tester1This standard is issued under the fixed designation D5591; the number immediately following the designation indicates the year oforiginal adoption or, in the c
2、ase of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () 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
3、of yarns and cords 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 applic
4、able range of thermalshrinkage 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 inform
5、ationonly.1.4 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. Spec
6、ific hazardsstatements are given in Section 8.2. Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD885 Test Methods for Tire Cords, Tire Cord Fabrics, andIndustrial Filament Yarns Made from ManufacturedOrganic-Base FibersD2258 Practice for Sampling Yarn for TestingD6477 T
7、erminology Relating to Tire Cord, Bead Wire,Hose Reinforcing Wire, 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 D6477.3.1.1.1 The following terms are relevant to this standard:adhesive-
8、treated tire cord, cord, greige cord, greige tire 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 D123.3.2.1 Th
9、e following terms are relevant to this standard: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 s
10、hrinkage force induced in the specimen is readfrom 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
11、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 are drawn from the materialfrom which the disparate test results were obtaine
12、d, 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 a statistical test for unpaired data, ata probability level chosen prior to th
13、e 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 Experience shows that yarns or cords on would pack-ages, usually being under tension, exhibit a contraction inlength (and
14、a resulting increase in linear density) whenremoved from the package and allowed to relax over a periodof time at room temperature. Consequently, it they are tested1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.19 on
15、Industrial Fibers andMetallic Reinforcements.Current edition approved Jan. 1, 2011. Published March 2011. Originallyapproved in 1995. Last previous edition approved in 2004 as D5591 04. DOI:10.1520/D5591-04R11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Custo
16、mer 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.without being allowed to relax, they
17、 will register higherthermal shrinkage force values as the relaxation shrinkage willbe incorrectly included 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 s
18、keins of nylon yarnor cord to 95 to 100 % relative humidity at room temperaturefor two days and reconditioning 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 lowerin
19、g of thermal shrink-age force.5.3 The thermal shrinkage force of nylon, polyester, andaramid fiber is related 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 critica
20、l in theusers subsequent operations, such as the drum-set (originallength of cord) required to build a tire 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
21、and their abilityto maintain tension during their operation.5.6 This test method is in agreement with the nominalprocedures of Methods D885 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 temperat
22、ure and after a specifiedlength of time.6. Interferences6.1 If the chamber in which the specimen is heated 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 lowerth
23、an those obtained with a shield.6.2 The accurate control of temperature at any prescribedsetting is of utmost 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 experi
24、ences may be checked byattaching a small calibrated thermocouple to a piece of cordand suspending it in the 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 o
25、r determine the proper setpoint to give the specified specimen temperature. An intralabo-ratory comparison 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 Shri
26、nkage force is a combination of pretension force andthe force that is developed in the specimen as a result 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
27、of any part ofthe specimen. Specimens that are spun, textured, or crimped(such as those removed from a fabric) 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. Ap
28、paratus7.1 Thermal Shrinkage Oven, consisting of a specimenheating cavity capable of heating up to 250C (480F), 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 o
29、f reading to 6 1.0 s.7.3 Clip-On Tensioning Masses.7.4 Draft Shield for Shrinkage Oven, if the oven does nothave 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
30、.9. Sampling9.1 Lot SampleAs a lot sample for acceptance testing,randomly select the number of shipping containers 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 dire
31、cted inPractice D2258. Consider shipping containers of yarn, cord androlls of fabric to be the lot sampling units.NOTE 1An adequate specification or other agreement between thepurchaser and the supplier requires taking into account the variabilitybetween shipping containers, between laboratory sampl
32、ing units within ashipping container, and between test specimens within a laboratorysampling unit to produce 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, proc
33、eed as follows:9.2.1 For yarn or cord, take at random the number ofpackages per shipping container in the 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
34、 directed inPractice D2258.9.2.2 For fabric, take a full-width swatch at least 1-m (1-yd)long from the outside 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 mate
35、rial.9.3 Test Specimens:9.3.1 For yarns and cords, strip at least 50 m (55 yd) fromthe outside of each package 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
36、no visible damage. Take at leastthree specimens, 600-mm (24-in.) long, from each package inthe laboratory sample. Discard and replace specimen lengthsthat are visibly damaged.D5591 04 (2011)29.3.2 For tire cord fabrics, remove a minimum of fivelengths of warp yarn or cord 600-mm (24-in.) long from e
37、achswatch in the laboratory sample, with the specimens beingtaken at least 75 mm (3 in.) from the selvage of the 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
38、-in.) long after discarding those portions within 75 mm (3in.) of the selvage of the swatch.9.3.2.1 The instructions 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
39、sample from which the specimens weretaken. The extra two specimens from fabric are taken to ensurethat a specimen free of handling damage is available afterconditioning. If the applicable material specification or otheragreement between the purchaser and the supplier specifiestesting more than three
40、 specimens per laboratory sample, anadditional two specimens above the number specified shouldbe taken from the 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
41、draftshield covering the three open sides of the heating chamber.10.2 Test in the standard atmosphere for testing 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
42、the atmosphere for testing industrial yarns(see 3.1). Ensure that no change in twist occurs while conduct-ing this 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 t
43、o 20 min afterprocessing) is agreed upon between the purchaser and thesupplier. Immediate testing must be reported 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 carr
44、iage assembly forwardagainst the front stops.12.3 Insert one end of the specimen through the open righthand clamp 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 App
45、ly the prescribed pretensioning mass to the freeend of the specimen (see Table 1) outside the left hand post.12.7 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
46、 the pretensioning mass.12.9 Push the carriage assembly back into the oven. Ensurethat the specimen is centered 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 star
47、tfeature.12.11 At the end of 120 6 5 s, read the maximum shrinkageforce on the instrument scale to the nearest 0.1 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 inD5591. Describe the material(s) or product(
48、s) tested and themethod of sampling used. Report the following information:13.1.1 Individual thermal shrinkage 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
49、 show theaverage force for a defined time interval.13.1.2 Pretension force used.13.1.3 Measurements as “immediate 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 laboratori
