1、Designation: D 3106 07Standard Test Method forPermanent Deformation of Elastomeric Yarns1This standard is issued under the fixed designation D 3106; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numbe
2、r 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 the determination of the perma-nent deformation of bare, continuous elastomeric monofila-ments and filament yarns m
3、ade from rubber, spandex, anidex,or other elastomers subjected to prolonged periods of tension.This test method is applicable to elastomeric yarns having alinear density in the range from 4 to 320 tex (36 to 2900 den.).1.2 This test method is not applicable to covered, wrapped,core-spun yarns, or ya
4、rns spun from elastomeric staple.1.3 This test method was developed using yarns in the“as-received” condition, but may be used for treated yarnsprovided the treatment is specified.1.4 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for information
5、only.1.5 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. Referen
6、ced Documents2.1 ASTM Standards:2D 123 Terminology Relating to TextilesD 2433 Test Methods for Rubber ThreadD 4849 Terminology Relating to Yarns and Fibers3. Terminology3.1 For all terminology relating to D13.58, Yarns andFibers, refer to Terminology D 4849.3.1.1 The following terms are relevant to
7、this standard:breaking force, elastomeric yarn, elongation, elongation atbreak, extension, force, linear density, length distribution,permanent deformation, velveteen.3.2 For all other terminology related to textiles, refer toTerminology D 123.4. Summary of Test Method4.1 The nominal linear density
8、of the sample is known ordetermined and the elongation at the breaking force is deter-mined from representative specimens.4.2 A specimen from the sample is placed in a pair ofline-contact clamps and held at a selected elongation for aspecified period of time. The permanent deformation or non-recover
9、able stretch is measured after a specified recoveryperiod.5. Significance and Use5.1 Test Method D 3106 for testing permanent deformationof elastomeric yarns is considered satisfactory for acceptancetesting of commercial shipments when there is prior agreementas to the exact value of elongation to b
10、e used for testing, sincecurrent estimates of between-laboratory precision are accept-able.5.1.1 If there are differences or practical significance be-tween reported test results for two laboratories (or more)comparative tests should be performed to determine if there isa statistical bias between th
11、em, using competent statisticalassistance. As a minimum, test samples that are as homoge-neous as possible, drawn from the material from which thedisparate test results were obtained, and randomly assigned inequal numbers to each laboratory for testing. The test resultsfrom the two laboratories shou
12、ld be compared using a statis-tical test for unpaired data, at a probability level chosen priorto the testing series. If bias is found, either its cause must befound and corrected, or future test results for that material mustbe adjusted in consideration of the known bias.5.2 Yarns are subjected to
13、long periods of tension resultingin an appreciable amount of stretch during normal use. Aportion of the induced stretch may be permanent. The amountof permanent deformation is influenced by the amount oftension, the time the yarn is under tension and the timeavailable for recovery between successive
14、 uses.1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.58 on Yarns and Fibers.Current edition approved Jan. 1, 2007. Published January 2007. Originallyapproved in 1972. Last previous edition approved in 2001 as D 3106 0
15、12For 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 International, 100 Barr Harbor Drive, PO Box
16、 C700, West Conshohocken, PA 19428-2959, United States.5.3 For optimum processing of elastomeric yarns, the per-manent deformation value should be low or zero.6. Apparatus6.1 Line-Contact Clamps, with one fixed clamp and onemovable clamp, assembled as directed in Appendix X1, and asshown in Fig. 1.6
17、.2 Tensioning Weights, 10 mg to 3 g, to pretension thespecimens before final clamping.NOTE 1Aluminum foil has been found to be suitable for use astensioning weights; the foil may be attached to the yarn by folding it overthe yarn.6.3 Stop Watch or Timer.7. Sampling7.1 Lot SampleAs a lot sample for a
18、cceptance testing,take at random the number of shipping cartons of elastomericyarn as directed in the applicable material specification or otheragreement between the purchaser and supplier. Consider thematerial shipping carton to be the primary sampling unit.7.2 Laboratory SampleAs a laboratory samp
19、le for accep-tance testing, take at random the number of packages fromeach shipping carton in the lot sample as directed in theapplicable material specification or other agreement betweenthe purchaser and the supplier. If differing numbers andpackages are to be taken from the shipping cartons in the
20、 lotsample, determine at random which shipping cartons are tohave each number of packages drawn.FIG. 1 Test Apparatus for Permanent SetD3106072NOTE 2An adequate specification or other agreement between thepurchaser and the supplier requires taking into account the variabilitybetween shipping cartons
21、, and the variability of the material within theshipping carton, to provide a sampling plan with a meaningful producersrisk, consumers risk, acceptable quality level, and limiting quality level.7.3 Test SpecimensFrom each package in the laboratorysample, take the number of specimens directed in Sect
22、ion 8.Inspect each package after withdrawing at least five layers ofyarn from the outside of the package. If there is evidence ofdamage, continue to withdraw units of five layers and reinspectuntil there is no discernible damage. Withdraw yarn over theend of the package and cut specimens approximate
23、ly 150 mmlong. Discard specimens that are damaged during withdrawalor cutting. Withdraw at least2mofyarn between specimensfrom a single package.8. Specimens Per Package8.1 Take a number of specimens per package such that theuser may expect at the 95 % probability level that the test resultis no more
24、 than 0.55 percentage points above or below the trueaverage of the package. Determine the number of specimens asfollows:8.1.1 Reliable Estimate of sWhen there is a reliableestimate of s based on extensive past records for similarmaterials tested in the users laboratory as directed in the testmethod,
25、 calculate the required number of specimens perpackage using (Eq 1):n 5 ts/E!2(1)where:n = number of specimens per package (rounded upward toa whole number),s = reliable estimate of the standard deviation of indi-vidual observations on similar materials in the userslaboratory under conditions of sin
26、gle-operator preci-sion,t = value of Students t for two-sided limits, a 95 %probability level, and the degree of freedom associatedwith the estimate of s (see Table 1), andE = 0.55 percentage points, the value of the allowablevariation.8.1.2 No Reliable Estimate of sWhen there is no reliableestimate
27、 of s for the users laboratory, (Eq 1) should not beused directly. Instead, specify the fixed number of ten speci-mens. This number of specimens is calculated using s = 0.87percentage point, which is a somewhat larger value of s than isusually found in practice. When a reliable estimate of s for the
28、users laboratory becomes available, (Eq 1) will usually requirefewer than ten specimens.9. Conditioning9.1 Condition the specimens in the standard atmosphere fortesting textiles, 65 6 2 % relative humidity and 21 6 1C (706 2F) temperature, in moving air for a minimum time of 16h. Preconditioning is
29、not necessary for the currently producedrubber and other elastomers having a moisture regain below1.0 % and low moisture hysteresis.10. Procedure10.1 Test all specimens in the standard atmosphere fortesting textiles.10.2 Determine the elongation at the breaking force for eachspecimen as directed in
30、Test Method D 2433.NOTE 3When Test Method D 3106 is used for acceptance testing, thelaboratory of the purchaser and the laboratory of the supplier should agreeon a specific value of the elongation at the breaking force.10.3 Determine the linear density for the sample as directedin Test Method D 2433
31、. The nominal linear density value maybe used.10.4 Adjust the line-contact clamps for a 100 mm nominalgage length (see Fig. 1). This is the original length of aspecimen.NOTE 4A convenient method for checking the gage length is to placea piece of carbon paper and white paper in the clamps and close t
32、heclamps. The distance between the marks on the whitepaper (made by thecarbon paper) is the nominal gage length. If the test apparatus isassembled as described in Appendix X1, the nominal gage length may beset directly.10.5 Fasten one end of the specimen in the top clamp. Passthe other end of the sp
33、ecimen through the lower clamp facesand through the toggle clamp. Attach a tensioning mass equalto 0.03 mN/tex (0.3 6 0.1 mgf/den.) to the yarn below thelower clamp, allowing the yarn to hang freely between the jawsof the lower clamp. Be sure the specimen remains in a verticalplane. Close the lower
34、clamp and remove the tensioning mass.(See Note 1.)10.6 Lower the movable clamp to stretch the specimen60 % of the average breaking elongation calculated to theTABLE 1 Values of Students tAfor One-Sided and Two-Sided Limits and the 95 % Probability LeveldF One-sided Two-sided dF One-sided Two-sided d
35、F One-sided Two-sided1 6.314 12.706 11 1.796 2.201 22 1.717 2.0742 2.920 4.303 12 1.782 2.179 24 1.711 2.0643 2.353 3.182 13 1.771 2.160 26 1.706 2.0564 2.132 2.776 14 1.761 2.145 28 1.701 2.0485 2.015 2.571 15 1.753 2.131 30 1.697 2.0426 1.943 2.447 16 1.746 2.120 40 1.684 2.0217 1.895 2.365 17 1.7
36、40 2.110 50 1.676 2.0098 1.860 2.306 18 1.734 2.101 60 1.671 2.0009 1.833 2.262 19 1.729 2.093 120 1.658 1.98010 1.812 2.228 20 1.725 2.086 1.645 1.960AValues in this table were calculated using Hewlett Packard HP 67/97 Users Library Programs 03848D, “One-sided and Two-sided Critical Values of Stude
37、nts t” and00350D,“ Improved Normal and Inverse Distribution.” For values at other than the 95 % probability level, see published tables of critical values of Students t in any standardstatistical test (2), (3), (4), and (5).D3106073nearest 1 mm. Take about5stolower the clamp and hold thespecimen in
38、this stretched condition for 10 6 1s.10.7 After the 10-s holding period, raise the lower clampuntil the specimen has a residual stretch of 20 % of the averagebreaking elongation calculated to the nearest 1 mm. Thismovement should take about 5 s. Hold the yarn in this positionfor4h6 10 min.NOTE 5Resu
39、lts have been found to be dependent upon the time tostretch as well as the amount of stretch imparted to the yarn. It isrecommended that prior to actual testing, the operator familiarize himselfwith the rate of stretch required to effect the total required stretch withinthe specified time limit.10.8
40、 At the end of the 4-h period, raise the lower clamp untilthe specimen has enough slack to prevent its coming undertension (becoming taut) as it recovers. Start the stop watch ortimer and hold the specimen in this condition for 10 min 6 30s.10.9 At the end of the recovery period, lower the moveablec
41、lamp until the specimen is just straight without beingstretched and measure the length of the specimen to the nearest0.5 mm. The measured length is the stretched length of aspecimen after a 10-min relaxation time.10.10 Raise the lower clamp immediately after measuringthe specimen, allowing enough sl
42、ack to prevent the specimenfrom becoming taut due to recovery. Hold the specimen in thiscondition for 100 6 5 min as measured by the stop watch ortimer.10.11 Remeasure the length of the specimen as directed in10.9. This is the stretched length of a specimen after a 100minrelaxation time.11. Calculat
43、ion11.1 Calculate the permanent deformation to the nearest0.5 % using (Eq 2):Permanent deformation, % 5 S 2 L!/L 3 100 (2)11.1.1 When L = 100 mm, (Eq 2) simplifies to the follow-ing:Permanent deformation, % 5 S 2 100 (3)where:S = stretched length of specimen at specified time, mm,andL = original len
44、gth of specimen, mm.11.2 Calculate the average permanent deformation after10-min and 100-min relaxation times.11.3 Calculate the coefficient of variation, if requested.12. Report12.1 State that the specimens were tested as directed in TestMethod D 3106. Describe the material or product sampled andth
45、e method of sampling used.12.2 Report the following information:12.2.1 The average breaking elongation,12.2.2 The average permanent deformation at 10-min and100min relaxation times to the nearest 0.5 %.12.2.3 The number of specimens tested, and12.2.4 The coefficient of variation, if calculated.13. P
46、recision and Bias13.1 SummaryIn comparing two averages of five obser-vations, the differences should not exceed .8 percentage pointsof the grand average of all of the observations in approximately95 cases out of 100 when all of the observations are taken bythe same well-trained operator using the sa
47、me piece of testequipment and specimens drawn randomly from the samesample of material.13.2 Interlaboratory Test DataAn interlaboratory test wasrun in 1969, in which two laboratories tested five specimensfrom each of three materials. Each laboratory used oneoperator to test each material. The within
48、-laboratory precisionand between-laboratory precision are expressed as standarddeviations, as follows:Single-operator component 0.62 percentage pointBetween-laboratory component 1.00 percentage point13.3 Critical DifferencesFor the components of variancereported in 13.1, two averages of observed val
49、ues should beconsidered significantly different at the approximate 95 %probability level, if the difference equals or exceeds the criticaldifference listed as follows:Critical Difference, Percentage Points, for the Condition NotedANumber of Observationsin Each AverageSingle-OperatorPrecisionBetween-LaboratoryPrecision2 1.2 3.05 0.8 2.910 0.5 2.8_AThe values for the critical differences were calculated using t = 1.960, which isbased on infinite degrees of freedom.NOTE 6This is a general statement with respect to between-laboratoryprecis
