1、Designation: D7138 08D7138 16 An American National StandardStandard 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 re
2、vision, 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 Either of two test methods are used to determine the melting temperature of thermoplastic fibers,
3、yarns, or threads.1.2 Method 1 can be used to determine melting temperatures for blends of multiple fiber material types. Method 2 can only beused to determine the melting temperature of a single fiber material type.1.2.1 Method 1, Differential Scanning Calorimetry (DSC), measures changes in heat ca
4、pacity and will detect the glass transition,the crystalline melting and endothermic thermal degradation.1.2.2 Method 2, a visual determination of melting, determines any change that visually appears as a transition from a solid toa liquid state.1.2.3 Due to the differences in what each test method m
5、easures, the results from Method 1 and Method 2 cannot be compared.1.3 The values stated in either SI units or other units are to be regarded separately. The values stated in each system are not exactequivalents; therefore, each system shall be used independently without combining values.1.4 This st
6、andard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 A
7、STM Standard:2D123 Terminology Relating to TextilesD1776 Practice for Conditioning and Testing TextilesD2257 Test Method for Extractable Matter in TextilesD3333 Practice for Sampling Manufactured Staple Fibers, Sliver, or Tow for Testing2.1 ASTM Standards:2D123 Terminology Relating to TextilesD276 T
8、est 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. Terminology3.1
9、Definitions of Terms Specific to This Standard:3.1.1 melting temperature, nthe temperature or range of temperatures at which a substance is observed to transition to aliquid-like state.3.1.2 For all other terminology related to textiles, see Terminology D123.4. Summary of Test Method4.1 Method 1:1 T
10、his test method is under the jurisdiction of ASTM Committee D13 on Textiles and is the direct responsibility of Subcommittee D13.51 on Conditioning and,Conditioning, Chemical and Thermal Properties.Current edition approved July 1, 2008Jan. 1, 2016. Published August 2008February 2016. Originally appr
11、oved in 2007. Last previous edition approved in 20072008 asD7138 - 07. - 08. DOI: 10.1520/D7138-08.10.1520/D7138-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to t
12、he standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes a
13、ccurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United
14、States14.1.1 A specimen of fiber and a reference sample are positioned into the designated heating blocks of a Differential ScanningCalorimetry (DSC) instrument.4.1.2 Use the DSC data to determine the fiber specimen melting temperature.4.2 Method 2:4.2.1 A specimen of fiber is positioned in a meltin
15、g temperature device.4.2.2 The temperature of the device is raised until the fiber specimen reaches its melting temperature as determined by visualobservation.5. Significance and Use5.1 Either of these two test methods is used to determine the temperature at which a synthetic fiber specimen changes
16、from asolid to a liquid-like state.5.1.1 Synthetic fibers may be either amorphous or semi-crystalline thermoplastics or thermosets. Synthetic fibers may changefrom the solid to a liquid-like state on heating because of the glass transition of amorphous polymers, the melting of crystallineregions of
17、semi-crystalline polymers, or at the onset of degradation. Thermoplastic fibers consist of crystalline and amorphousregions and may be manufactured with a range of molecular weights. The amorphous and crystalline fiber structure and variablemolecular weight can lead to a melting temperature range in
18、stead of a discreet melting point (see Table X1.1).5.2 This test method is considered satisfactory for acceptance testing of commercial shipments.5.2.1 If there are differences of practical significance between reported test results for two or more laboratories, performcomparative testing to determi
19、ne if there is a statistical bias between them, using competent statistical assistance. As a minimum,use the samples for such a comparative test that are as homogeneous as possible, drawn from the same lot of material as thesamples that resulted in disparate results during initial testing and random
20、ly assigned in equal numbers to each laboratory. Comparethe test results from the laboratories involved using a statistical test for unpaired data, at a probability level chosen prior to thetesting series. If bias is found, either its cause must be found and corrected, or future test results for tha
21、t material must be adjustedin consideration of the known bias.5.3 This test method is suitable for quality control testing of synthetic fibers and product comparisons of different fibers bymanufacturers, retailers, and users.5.4 If the test method is used to identify fiber material type, it is impor
22、tant to test a known reference material at the samelaboratory with the same test method to confirm the fiber identification. In addition, since some fiber types have similar meltingtemperatures or overlapping melting temperature ranges as show in Table X1.1, secondary methods for fiber identificatio
23、n asdescribed in Test Methods D276 will be required 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 ConfigurationApparatus used consists of an electrically heated stage which has a temperature range from 20C(68F)
24、 to 300C (572F) or at least 10C (18F) above the highest melting temperature to be measured. See Fig. X1.1 for a typicalapparatus.6.2.1.1 The adjustment mechanism shall be able to control the heat input into the stage.6.2.1.2 Thermometer for measuring temperature shall be accurate to +0.5C (+1F).6.2.
25、1.3 The device shall have a low powered magnifying glass to permit visual examination.6.2.1.4 The device shall have a top and bottom microcover glass. The top glass shall fit directly over the bottom glass so thatthe fiber specimen rests between the microcovers.6.2.2 Soxhlet extraction device. See F
26、ig. X1.2.7. Preparation of Apparatus7.1 Lot Sample: As a lot sample for acceptance testing, take at random the number of laboratory sampling units as directed inan applicable material specification or other agreement between the purchaser and the supplier. In the absence of a materialspecification o
27、r other agreement, use Practice D2258 or Practice D3333, as applicable. Consider containers, such as cartons, balesor other shipping containers to be the primary sampling units.7.2 Laboratory Sample Unit: As a laboratory sampling unit for acceptance testing, take as directed in Practice D2258 or Pra
28、cticeD3333, as applicable. If the fiber sample requires cleaning using a Soxhlet extractor proceed to 7.2.1. If cleaning using a Soxhletextractor is not required proceed to 7.3.7.2.1 Place sample in a Soxhlet extractor (see Fig. X1.2) and perform twenty extractions using a chloroform, USP reagent.Fo
29、llow extraction procedure in D2257. Other solvents such as methanol, ethanol or isopropyl alcohol may be used if they are foundto be effective in removing fiber finishes and coatings.7.2.2 Dry samples and return to equilibrium in accordance with D1776.D7138 1627.3 Test Specimens:7.3.1 Method 1:7.3.1
30、.1 DSC Sample PreparationCut the samples into very small pieces with scissors and put a 5 to 7 mg specimen into thealuminum pan. Make a small hole on the lid with a needle and close the pan with the help of a sample crimper. Make anothersample, which will be used as the reference sample by closing a
31、n empty pan with lid.7.3.1.2 Prepare five specimens and five references to perform five replicates.7.3.2 Method 2:7.3.2.1 From each laboratory sampling unit, cut five fiber samples into specimens having a length of approximately 2 mm (.0625in).7.3.2.2 Prepare the five specimens to perform five repli
32、cates.8. Calibration8.1 Follow the manufacturers instructions to calibrate the melting temperature apparatus (see Appendix X1).8.2 Verify the melting temperature apparatus performance by using fiber of a known melting temperature (see Table X1.1).NOTE 1 Use a fiber having a melting temperature simil
33、ar to the specimen to be tested (see Table X1.1).NOTE 2Avoid using a fiber with a wide melting temperature range as the verification fiber (see Table X1.1).8.2.1 Verification is achieved when the melting temperature of the verification fiber used is within +1C (+2F) of its knownvalue.9. Test Procedu
34、re9.1 Procedure for Method 1:9.1.1 Put the specimen and the reference in the designated heating blocks (in accordance with the instrument manufacturersmanual) inside the heater chamber. Close the chamber, and start heating at the rate of 10C/min to approximately 50C above themelting point of the fib
35、er being tested in accordance with Table X1.1.9.1.2 Record the temperature. Cool the chamber, and repeat the measurement on a new specimen until five specimens arecompleted.9.2 Procedure for Method 2:9.2.1 Place a specimen consisting of a sufficient quantity of fibers to observe specimen melting, ap
36、proximately 50 cut fibers,on the bottom microcover glass of the test apparatus and cover with the top micro glass.9.2.2 If the fiber melting temperature is known, set the dial of the test apparatus to a temperature 15C (+27F) below theanticipated melting temperature. Proceed to 9.2.5.9.2.3 If the me
37、lting temperature is not known before testing, it can be determined by using the following approach:9.2.3.1 Place the specimen in the apparatus and elevate the temperature to 140C (284F). If the specimen melts, test the nextspecimen, after cool down of the apparatus, at a temperature 20C (36F) lower
38、. If the specimen does not melt, proceed to 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) per minute until the fiber demonstrates melting.9.2.5 Observe the specimen using the magnifying glass.9.2.6 Read the temperature to nearest
39、degree C (F) on the test apparatus when it is observed that the solid demonstrates a liquidflow.10. Final Test Report10.1 Report that the melting temperature of fibers was determined as directed in Test Method D7138. Indicate whether Method1 or Method 2 was used to determine the melting temperature.
40、 Describe the material or product sampled and the method ofsampling used.10.2 Report the following information for the laboratory sampling unit and for the lot as applicable to a material specificationor contract order. For Method 1, if a fiber blend sample is tested, report the results for each fib
41、er type in the blend sample.10.2.1 Report the melting temperature of each of the five replicates to the nearest degree C (F).10.2.2 Calculate and report the average melting temperature of the five replicates to the nearest degree C (F).11. Precision and Bias11.1 Precision and Bias for Method 1:11.2
42、Precision and Bias for Method 2:11.2.1 PrecisionThe repeatability standard deviation has been determined to be 1.3C for a polyester sample and 2.1C for anylon sample. The 95 % confidence limit for the polyester sample is 240 6 2C and for the 66 nylon sample is 238 6 3C. Thereproducibility of this te
43、st method is being determined and will be available on or before January 31, 2009.D7138 16311.2.2 BiasNo information can be presented on the bias of the procedure in Test Method D7138 because no fiber materialhaving an accepted reference value is available. It may be possible to determine bias using
44、 non-fiber crystalline materials, and thiswill be addressed in later editions.12. Keywords12.1 differential scanning calorimetry; melting; synthetic fibersAPPENDIXX1. Melting Temperature Apparatus and Typical Fiber Melting TemperaturesX1.1 The purpose of the melting or apparent melting temperatures
45、and melting temperature ranges listed in Table X1.1 is to assistin establishing the starting temperature for a fiber melting or apparent temperature determination when the fiber type is known.It is not known whether the listed melting temperatures were determined by Method 1 or Method 2.D7138 164X1.
46、2 ApparatusSee Fig. X1.1 and Fig. X1.2.TABLE X1.1 List of Approximate Fiber Melting or Apparent Melting Temperatures and Temperature RangesA,B ,CFiber Type Melting Temperature, CVinyon HH Softens at 85PVC About 100Polyethylene 135 - 160Polypropylene 164 - 170Chlorofibre 162 - 167Saran 166 and 170Nyt
47、ril 176Modacrylic 184Polyamid (Nylon) 6 216 and 219Spandex 230Polyurethane 230 - 260Polyamide (Nylon) 6-6 238 - 260Polyester 240 - 250Polyacrylonitrile 235 - 330Acetate 260Polycarbonate 294Triacetate 288 and 300Polytetrafluoroethylene 327TABLE X1.1 List of Approximate Fiber Melting or Apparent Melti
48、ng Temperatures and Temperature RangesA,BFiber Type Glass TransitionTemperature, C MeltingTemperature, C DecompositionTemperature, CAcetate 230 260Aromatic homocyclicpolyster330Benzoxazole, p-phenylene 650Carbon 650Chlorofibre 162 167m-Aramid 340 n/aC 550Modacrylic 184p-Aramid 275 n/a 400Polyacrylon
49、itrile 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 140Polypropylene 15 170Polytetrafluoroethylene 126 327Polyurethane 230 260Polyvinylchloride 87 182 140Saran 177Spandex 232Triacetate 288 and 300Vinyon HH 85Viscose 290A In some cases degradation takes place prior to or instead of melting. Data originates from different sources and may be subjected to deviations introduced by
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