1、Designation: D 7138 07An American National StandardStandard Test Method toDetermine Melting Temperature of Synthetic Fibers1This standard is issued under the fixed designation D 7138; 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 Either of two test methods are used to determine themelting temperature of thermoplastic fibers, yarns,
3、or threads.1.2 Method 1 can be used to determine metling tempera-tures for blends of multiple fiber material types. Method 2 canonly be used to determine the melting temperature of a singlefiber material type.1.3 The values stated in either SI units or other units are tobe regarded separately. The v
4、alues 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 thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establi
5、sh appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standard:2D 123 Terminology Relating to TextilesD 276 Test Methods for Identification of Fibers in TextilesD 1776 Practice for Conditioning and Testing
6、TextilesD 2257 Test Method for Extractable Matter in TextilesD 2258 Practice for Sampling Yarn for TestingD 3333 Practice for Sampling Manufactured Staple Fibers,Sliver, or Tow for Testing3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 melting temperature, n the temperature or
7、 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 D 123.4. Summary of Test Method4.1 Method 1:4.1.1 A specimen of fiber and a reference sample arepositioned into the designated heating blocks
8、 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 melting tem-perature device.4.2.2 The temperature of the device is raised until the fiberspecimen reaches its me
9、lting 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 changes froma solid to a liquid-like state.5.1.1 Synthetic fibers may be either amorphous or semi-crystalline therm
10、oplastics 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 semi-crystalline polymers, or at the onsetof degradation. Thermoplastic fibers consist of crystalline andamo
11、rphous 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 instead of a discreet melting point (see Table1).5.2 This test method is considered satisfactory for accep-tanc
12、e testing of commercial shipments.5.2.1 If there are differences of practical significance 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 sam
13、ples for such a comparative test that areas homogeneous as possible, drawn from the same lot ofmaterial as the samples that resulted in disparate results during1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.51 on Cond
14、itioning and,Chemical and Thermal Properties.Current edition approved May 1, 2007. Published July 2007.2For 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
15、 Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.initial testing and randomly assigned in equal numbers to eachlaboratory. Compare the test results from the laboratoriesinvolved using a statis
16、tical test for unpaired data, at a prob-ability level chosen prior to the testing series. 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 tes
17、ting ofsynthetic fibers and product comparisons of different fibers bymanufacturers, retailers, and users.6. Apparatus6.1 Apparatus for Method 1, using a DSC instrument :6.2 Apparatus for Method 2:6.2.1 Test Unit ConfigurationApparatus used consists ofan electrically heated stage which has a tempera
18、ture 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 stage.6.2.1.2 Thermometer for measuring temperature shall beaccurat
19、e 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 the fiber specimen rests between the microcovers.6.2.2 Soxhlet extr
20、action device. See Fig. X1.2.7. Preparation of Apparatus7.1 Lot Sample:As a lot sample for acceptance testing, take at random thenumber of laboratory sampling units as directed in an appli-cable material specification or other agreement between thepurchaser and the supplier. In the absence of a mate
21、rialspecification or other agreement, use Practice D 2258 orPractice D 3333, as applicable. Consider containers, such ascartons, bales or other shipping containers to be the primarysampling units.7.2 Laboratory Sample Unit:As a laboratory sampling unit for acceptance testing, take asdirected in Prac
22、tice D 2258 or Practice D 3333, as applicable.If the fiber sample requires cleaning using a Soxhlet extractorproceed to 7.2.1. If cleaning using a Soxhlet extractor is notrequired proceed to 7.3.7.2.1 Place sample in a Soxhlet extractor (see Fig. 1) andperform twenty extractions using a chloroform,
23、USP reagent.Follow extraction procedure in D 2257. Other solvents such asmethanol, ethanol or isopropyl alcohol may be used if they arefound to be effective in removing fiber finishes and coatings.7.2.2 Dry samples and return to equilibrium in accordancewith D 1776.7.3 Test Specimens:7.3.1 Method 1:
24、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 sample, which will be used as the referencesample by closing an em
25、pty 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 in).7.3.2.2 Prepare the five specimens to perform five repli-cate
26、s.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 Table 1).NOTE 1 Use a fiber having a melting temperature similar to thes
27、pecimen to be tested (see Table 1).NOTE 2Avoid using a fiber with a wide melting temperature range asthe verification fiber (see Table 1).8.2.1 Verification is achieved when the melting temperatureof the verification fiber used is within + 1C (+2F) of itsknown value.9. Test Procedure9.1 Procedure fo
28、r 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 to approximately 50Cabove the melting point of the fiber being tested i
29、n accordancewith Table 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 :TABLE 1 List of Typical Fiber Melting Temperatures andTemperature RangesA,B,CFiber Type Melting Temperature, CVinyon HH S
30、oftens at 85PVC About 100Polyolefin 135 - 160Polypropylene 164 -170Chlorofibre 162 - 167SaranT 166 and 170Nytril 176Modacrylic 184Polyamid(Nylon) 6 216 and 219Spandex 230Polyurethane 230-260Polyamide(Nylon)6-6 244 - 260Polyester 244 - 250Polyacrylonitrile 235-330Acetate 260Polycarbonate 294Triacetat
31、e 288 and 300Polytetrafluoroethylene 327AIn some cases degradation takes place prior to or instead of melting.B, Alex and Rollo, Bruce (1973), The WIRA Textile Data Book, Wira, LeedsCPractice D 276 Standard Test Methods for Identification of Fibers in TextilesD71380729.2.1 Place a specimen consistin
32、g of a sufficient quantity offibers to observe specimen melting, approximately 50 cutfibers, on the bottom microcover glass of the test apparatus andcover with the top micro glass.9.2.2 If the fiber melting temperature is known, set the dialof the test apparatus to a temperature 15C (+27F) below the
33、anticipated melting temperature. Proceed to 9.5.9.2.3 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
34、 cool down of the apparatus, at a tempera-ture 20C (36F) lower. If the specimen does not melt, proceedto 9.5.9.2.3.2 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 t
35、he 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 D 7138. Indicatewhether Method 1 o
36、r Method 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.10.2.1 Report the melting
37、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 Bias11.1 Precision and Bias for Method 1:11.2 Precision and Bias for Method 2:11.2.1 PrecisionThe repe
38、atability standard deviation hasbeen determined to be 1.26C for a polyester sample and2.06C for a nylon sample. The 95% confidence limit for thepolyester sample is 240.25 6 2.00C and for the nylon sampleis 237.75 6 3.28 C. The reproducibility of this test method isbeing determined and will be availa
39、ble on or before June 30,2007.11.2.2 BiasNo information can be presented on the biasof the procedure in Test Method D 7138 because no fibermaterial having an accepted reference value is available. It maybe possible to determine bias using non-fiber crystallinematerials, and this will be addressed in
40、 later editions.12. Keywords12.1 differential scanning calorimetry; melting; syntheticfibersAPPENDIXX1. Melting Temperature Apparatus and Typical Fiber Melting TemperaturesX1.1 See Fig. X1.1 and Fig. X1.2.D7138073FIG. X1.1 Melting Temperature ApparatusFIG. X1.2 Soxhlet Extraction ApparatusD7138074AS
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