ASTM F766-1982(2005) Standard Test Method for Melting Point of Waxes《蜡的熔点试验方法》.pdf

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1、Designation: F 766 82 (Reapproved 2005)Standard Test Method forMelting Point of Waxes1This standard is issued under the fixed designation F 766; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in

2、 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 initialand final melting points and recovery point of waxes using ahot stage and microscope.1.

3、2 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. See Section 8 fo

4、r aspecific precautionary statement.2. Referenced Documents2.1 ASTM Standards:2E 105 Practice for Probability Sampling of MaterialsE 122 Practice for Calculating Sample Size to Estimate,With a Specified Tolerable Error, the Average for Charac-teristic of a Lot or Process3. Descriptions of Terms Spec

5、ific to This Standard3.1 final melting pointthe temperature in degrees celsiusobserved on the hot-stage thermometer at the time the wax iscompletely melted into droplets.3.2 initial melting pointthe temperature in degrees celsiusobserved on the hot-stage thermometer at the time the firstmovement is

6、noted in the wax.3.3 recovery point the temperature in degrees celsiusobserved on the hot-stage thermometer at the time the firstcrystal is observed forming in the melted wax during cooling.4. Summary of Test Method4.1 A few shavings or granules from representative waxsample are placed on a microsco

7、pe slide and covered with acover glass. The slide assembly is set up on the hot stage withthe microscope lighted and focused for best viewing. The hotstage is heated rapidly at first and then adjusted so that itstemperature will increase approximately 2C/min during thelast 10C preceding the expected

8、 melting point. The waxshavings or granules are observed through the microscope, andthe temperature at which first movement of wax is noted isrecorded as initial melting point. The temperature at the timethe wax is observed to be completely melted is recorded as thefinal melting point. The hot stage

9、 is slowly cooled and thetemperature at which the first crystal appears in the melted waxis recorded as the recovery point. The recorded temperaturesare adjusted, where applicable, by appropriate temperaturecorrection factors.5. Significance and Use5.1 This test method determines the initial melting

10、 point andmelting range of waxes. The data obtained are important in theapplication of waxes in one-time carbon inks.6. Apparatus6.1 Controlled Micro Hot Stage and Microscope,40to503power or suitable alternative.6.2 Microscope Slides,1by112 in.6.3 No. 2 Cover Slides (glasses), 18 mm square.7. Materi

11、als7.1 Test Reagent Set, containing substances with knownmelting points for checking the accuracy of the hot-stagethermometer3.8. Precautions8.1 Not all waxes exhibit a uniform flow. Some waxesexhibit a sharp initial flow while others may exhibit a slower,gradual plastic flow.9. Sampling9.1 Ensure t

12、hat the sample represents the material tested andthat the portion of the test sample is representative of the wholesample. (Practices E 122 and E 105.)1This test method is under the jurisdiction ofASTM Committee F05 on BusinessImaging Products and is the direct responsibility of Subcommittee F05.02

13、on InkedTransfer Imaging Products.Current edition approved June 1, 2005. Published August 2005. Originallyapproved in 1982. Last previous edition approved in 2000 as F 766 82 (2000)e1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm

14、.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The sole source of supply of the apparatus known to the committee at this timeis Thomas Scientific, PO Box 99, Swedesboro, NJ 08085. If you are aware ofalternative suppliers, p

15、lease provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United Stat

16、es.9.2 Prepare sufficient wax to give 10 6 2 mg of sample foreach melting point determination. Brittle wax (such as car-nauba) is prepared by grinding the sample in a mortar andpestle or other suitable means and passing the wax through a200-mesh sieve. Non-brittle wax (such as paraffin) is preparedb

17、y shaving off a few small particles with a razor or other sharpinstruments.10. Calibration10.1 Check the hot-stage apparatus and thermometer regu-larly with test reagents having known melting points. To ensuremaximum accuracy, record at least three readings over therange of the thermometer utilized

18、and average each group ofreadings to obtain temperature corrections. Record any tem-perature corrections for the thermometer tested.10.2 The heat control dial of the hot-stage apparatus isgenerally graduated. The temperature gradient produced by thevarious settings of the control must be predetermin

19、ed tomaintain a specific heating rate when determining meltingpoint. Periodically check these temperature gradients andrecord any revisions regarding the heat control dial heatingrate.11. Procedure11.1 Using a spatula, transfer 10 6 2 mg of the prepared testwax onto a microscope slide.11.2 Cover the

20、 wax sample with a cover glass and carefullyplace the sample assembly on the hot stage. Follow themanufacturers instructions for the instruments being used.11.3 Adjust the microscope lamp or the mirror, or both, forbest viewing. Focus the microscope using 40 to 503 power tobring the selected wax sam

21、ple into sharp detail.11.4 Turn on the hot-stage heat control and set the control sothat the stage will heat to within 10C of the expected meltingpoint of the sample at a rate of approximately 3C/min.11.5 When the temperature of the stage reaches to approxi-mately 10C of the expected melting point,

22、reset the heatcontrol so that the temperature of the stage increases approxi-mately 2C/min.11.6 Observe the wax through the microscope and recordthe temperature of initial (first movement of wax) and final(wax completely melted) melting points.11.7 Rotate the ocular for maximum definition and contin

23、ueobserving the melted wax. Reduce the heat control setting andrecord the temperature at which the first crystal appears as therecovery point.12. Calculation and Results12.1 Correct the observed temperature in accordance withthe thermometer calibration and report to the nearest 1C.13. Precision13.1

24、Repeatability Duplicate determinations (one opera-tor and apparatus) on uniform samples should not differ bymore than 2C.13.2 Reproducibility Melting point differences betweenseparate testing facilities using different manufacturers testinstruments could exist because of variability between theseins

25、truments.14. Keywords14.1 melting; melting point; waxesASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent

26、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 technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either

27、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 hear

28、ing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).F 766 82 (2005)2