1、Designation: D7138 16Standard Test Method toDetermine Melting Temperature of Synthetic Fibers1This standard is issued under the fixed designation D7138; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A n
2、umber in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 Either of two test methods are used to determine themelting temperature of thermoplastic fibers, yarns, or threads.1.2 Method 1 can be u
3、sed to determine melting tempera-tures for blends of multiple fiber material types. Method 2 canonly be used to determine the melting temperature of a singlefiber material type.1.2.1 Method 1, Differential Scanning Calorimetry (DSC),measures changes in heat capacity and will detect the glasstransiti
4、on, the crystalline melting and endothermic thermaldegradation.1.2.2 Method 2, a visual determination of melting, deter-mines any change that visually appears as a transition from asolid to a liquid state.1.2.3 Due to the differences in what each test methodmeasures, the results from Method 1 and Me
5、thod 2 cannot becompared.1.3 The values stated in either SI units or other units are tobe regarded separately. The values stated in each system are notexact equivalents; therefore, each system shall be used inde-pendently without combining values.1.4 This standard does not purport to address all of
6、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 Documents2.1 ASTM Standards:2D123 Terminology Relating
7、 to TextilesD276 Test Methods for Identification of Fibers in TextilesD1776 Practice for Conditioning and Testing TextilesD2257 Test Method for Extractable Matter in TextilesD2258 Practice for Sampling Yarn for TestingD3333 Practice for Sampling Manufactured Staple Fibers,Sliver, or Tow for Testing3
8、. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 melting temperature, nthe temperature or range oftemperatures at which a substance is observed to transition toa liquid-like state.3.1.2 For all other terminology related to textiles, seeTerminology D123.4. Summary of Test Method4
9、.1 Method 1:4.1.1 A specimen of fiber and a reference sample arepositioned into the designated heating blocks of a DifferentialScanning Calorimetry (DSC) instrument.4.1.2 Use the DSC data to determine the fiber specimenmelting temperature.4.2 Method 2:4.2.1 A specimen of fiber is positioned in a mel
10、ting tem-perature device.4.2.2 The temperature of the device is raised until the fiberspecimen reaches its melting temperature as determined byvisual observation.5. Significance and Use5.1 Either of these two test methods is used to determine thetemperature at which a synthetic fiber specimen change
11、s froma solid to a liquid-like state.5.1.1 Synthetic fibers may be either amorphous or semi-crystalline thermoplastics or thermosets. Synthetic fibers maychange from the solid to a liquid-like state on heating becauseof the glass transition of amorphous polymers, the melting ofcrystalline regions of
12、 semi-crystalline polymers, or at the onsetof degradation. Thermoplastic fibers consist of crystalline andamorphous regions and may be manufactured with a range ofmolecular weights. The amorphous and crystalline fiber struc-ture and variable molecular weight can lead to a meltingtemperature range in
13、stead of a discreet melting point (see TableX1.1).5.2 This test method is considered satisfactory for accep-tance testing of commercial shipments.1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.51 on Conditioning, Chem
14、icaland Thermal Properties.Current edition approved Jan. 1, 2016. Published February 2016. Originallyapproved in 2007. Last previous edition approved in 2008 as D7138 - 08. DOI:10.1520/D7138-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at s
15、erviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.2.1 If there are differences of practical significa
16、nce be-tween reported test results for two or more laboratories,perform comparative testing to determine if there is a statisticalbias between them, using competent statistical assistance. As aminimum, use the samples for such a comparative test that areas homogeneous as possible, drawn from the sam
17、e lot ofmaterial as the samples that resulted in disparate results duringinitial testing and randomly assigned in equal numbers to eachlaboratory. Compare the test results from the laboratoriesinvolved using a statistical test for unpaired data, at a prob-ability level chosen prior to the testing se
18、ries. If bias is found,either its cause must be found and corrected, or future testresults for that material must be adjusted in consideration of theknown bias.5.3 This test method is suitable for quality control testing ofsynthetic fibers and product comparisons of different fibers bymanufacturers,
19、 retailers, and users.5.4 If the test method is used to identify fiber material type,it is important to test a known reference material at the samelaboratory with the same test method to confirm the fiberidentification. In addition, since some fiber types have similarmelting temperatures or overlapp
20、ing melting temperatureranges as show in Table X1.1, secondary methods for fiberidentification as described in Test Methods D276 will berequired to make fiber identifications.6. Apparatus6.1 Apparatus for Method 1, using a DSC instrument:6.2 Apparatus for Method 2:6.2.1 Test Unit ConfigurationAppara
21、tus used consists ofan electrically heated stage which has a temperature range from20C (68F) to 300C (572F) or at least 10C (18F) above thehighest melting temperature to be measured. See Fig. X1.1 fora typical apparatus.6.2.1.1 The adjustment mechanism shall be able to controlthe heat input into the
22、 stage.6.2.1.2 Thermometer for measuring temperature shall beaccurate to +0.5C (+1F).6.2.1.3 The device shall have a low powered magnifyingglass to permit visual examination.6.2.1.4 The device shall have a top and bottom microcoverglass. The top glass shall fit directly over the bottom glass sothat
23、the fiber specimen rests between the microcovers.6.2.2 Soxhlet extraction device. See Fig. X1.2.7. Preparation of Apparatus7.1 Lot Sample: As a lot sample for acceptance testing, takeat random the number of laboratory sampling units as directedin an applicable material specification or other agreeme
24、ntbetween the purchaser and the supplier. In the absence of amaterial specification or other agreement, use Practice D2258or Practice D3333, as applicable. Consider containers, such ascartons, bales or other shipping containers to be the primarysampling units.7.2 Laboratory Sample Unit: As a laborat
25、ory sampling unitfor acceptance testing, take as directed in Practice D2258 orPractice D3333, as applicable. If the fiber sample requirescleaning using a Soxhlet extractor proceed to 7.2.1. If cleaningusing a Soxhlet extractor is not required proceed to 7.3.7.2.1 Place sample in a Soxhlet extractor
26、(see Fig. X1.2)and perform twenty extractions using a chloroform, USPreagent. Follow extraction procedure in D2257. Other solventssuch as methanol, ethanol or isopropyl alcohol may be used ifthey are found to be effective in removing fiber finishes andcoatings.7.2.2 Dry samples and return to equilib
27、rium in accordancewith D1776.7.3 Test Specimens:7.3.1 Method 1:7.3.1.1 DSC Sample PreparationCut the samples intovery small pieces with scissors and puta5to7mgspecimeninto the aluminum pan. Make a small hole on the lid with aneedle and close the pan with the help of a sample crimper.Make another sam
28、ple, which will be used as the referencesample by closing an empty pan with lid.7.3.1.2 Prepare five specimens and five references to per-form five replicates.7.3.2 Method 2:7.3.2.1 From each laboratory sampling unit, cut five fibersamples into specimens having a length of approximately 2mm (.0625 i
29、n).7.3.2.2 Prepare the five specimens to perform five repli-cates.8. Calibration8.1 Follow the manufacturers instructions to calibrate themelting temperature apparatus (see Appendix X1).8.2 Verify the melting temperature apparatus performanceby using fiber of a known melting temperature (see TableX1
30、.1).NOTE 1 Use a fiber having a melting temperature similar to thespecimen to be tested (see Table X1.1).NOTE 2Avoid using a fiber with a wide melting temperature range asthe verification fiber (see Table X1.1).8.2.1 Verification is achieved when the melting temperatureof the verification fiber used
31、 is within +1C (+2F) of its knownvalue.9. Test Procedure9.1 Procedure for Method 1:9.1.1 Put the specimen and the reference in the designatedheating blocks (in accordance with the instrument manufactur-ers manual) inside the heater chamber. Close the chamber, andstart heating at the rate of 10C/min
32、to approximately 50Cabove the melting point of the fiber being tested in accordancewith Table X1.1.9.1.2 Record the temperature. Cool the chamber, and repeatthe measurement on a new specimen until five specimens arecompleted.9.2 Procedure for Method 2:9.2.1 Place a specimen consisting of a sufficien
33、t quantity offibers to observe specimen melting, approximately 50 cutfibers, on the bottom microcover glass of the test apparatus andcover with the top micro glass.D7138 1629.2.2 If the fiber melting temperature is known, set the dialof the test apparatus to a temperature 15C (+27F) below theanticip
34、ated melting temperature. Proceed to 9.2.5.9.2.3 If the melting temperature is not known beforetesting, it can be determined by using the following approach:9.2.3.1 Place the specimen in the apparatus and elevate thetemperature to 140C (284F). If the specimen melts, test thenext specimen, after cool
35、 down of the apparatus, at a tempera-ture 20C (36F) lower. If the specimen does not melt, proceedto 9.2.5.9.2.3.2 Continue this process until the fiber does not melt.9.2.4 Gradually raise the temperature at 3C (+5F) perminute until the fiber demonstrates melting.9.2.5 Observe the specimen using the
36、magnifying glass.9.2.6 Read the temperature to nearest degree C (F) on thetest apparatus when it is observed that the solid demonstrates aliquid flow.10. Final Test Report10.1 Report that the melting temperature of fibers wasdetermined as directed in Test Method D7138. Indicatewhether Method 1 or Me
37、thod 2 was used to determine themelting temperature. Describe the material or product sampledand the method of sampling used.10.2 Report the following information for the laboratorysampling unit and for the lot as applicable to a materialspecification or contract order. For Method 1, if a fiber blen
38、dsample is tested, report the results for each fiber type in theblend sample.10.2.1 Report the melting temperature of each of the fivereplicates to the nearest degree C (F).10.2.2 Calculate and report the average melting temperatureof the five replicates to the nearest degree C (F).11. Precision and
39、 Bias11.1 Precision and Bias for Method 1:11.2 Precision and Bias for Method 2:11.2.1 PrecisionThe repeatability standard deviation hasbeen determined to be 1.3C for a polyester sample and 2.1Cfor a nylon sample. The 95 % confidence limit for the polyestersample is 240 6 2C and for the 66 nylon samp
40、le is 238 63C. The reproducibility of this test method is being deter-mined and will be available on or before January 31, 2009.11.2.2 BiasNo information can be presented on the bias ofthe procedure in Test Method D7138 because no fiber materialhaving an accepted reference value is available. It may
41、 bepossible to determine bias using non-fiber crystalline materials,and this will be addressed in later editions.12. Keywords12.1 differential scanning calorimetry; melting; syntheticfibersAPPENDIXX1. Melting Temperature Apparatus and Typical Fiber Melting TemperaturesX1.1 The purpose of the melting
42、 or apparent meltingtemperatures and melting temperature ranges listed in TableX1.1 is to assist in establishing the starting temperature for afiber melting or apparent temperature determination when thefiber type is known. It is not known whether the listed meltingtemperatures were determined by Me
43、thod 1 or Method 2.X1.2 ApparatusSee Fig. X1.1 and Fig. X1.2.D7138 163TABLE X1.1 List of Approximate Fiber Melting or Apparent Melting Temperatures and Temperature RangesA,BFiber TypeGlass TransitionTemperature, CMeltingTemperature, CDecompositionTemperature, CAcetate 230 260Aromatic homocyclicpolys
44、ter330Benzoxazole, p-phenylene 650Carbon 650Chlorofibre 162 167m-Aramid 340 n/aC550Modacrylic 184p-Aramid 275 n/a 400Polyacrylonitrile 235 330 317Polyamide 6 50 210 225Polyamide 6-6 50 252 265 400Polycarbonate 143 223 252Polyester 75 240 255Polyethylene HDPE 120 144 155Polyethylene LDPE 120 110 140P
45、olypropylene 15 170Polytetrafluoroethylene 126 327Polyurethane 230 260Polyvinylchloride 87 182 140Saran 177Spandex 232Triacetate 288 and 300Vinyon HH 85Viscose 290AData originates from different sources and may be subjected to deviations introduced by the use of different measuring procedures.BRefer
46、ences:Potter, C., Thermal Analysis of Textile Fibers, AATCC Review, Sept./Oct. 2012, pp. 39-45.van ver Vegt, A. K., and Govaert, L. E., Polymeren van keten tot kunststof, ISBN 9789071301483, 2005.Rea, A., and Rollo, B., The WIRA Textile Data Book, ISBN 9780900820076, 1973.van Krevelen, D. W., and te
47、n Nijenhuis, K., Properties of Polymers, ISBN 9780080548197, 2009.Kohan, Melvin I., Nylon Plastics Handbook, ISBN 1569901899.CNot applicable.FIG. X1.1 Melting Temperature ApparatusD7138 164ASTM International takes no position respecting the validity of any patent rights asserted in connection with a
48、ny item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technica
49、l committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address sh
