1、Designation: D 3944 88 (Reapproved 2005)An American National StandardStandard Test Method forSolidification Point of Petroleum Wax1This standard is issued under the fixed designation D 3944; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a procedure for rapidly deter-mining the solidification point of petroleu
3、m wax.NOTE 1This test method is also applicable to similar materials such assynthetic waxes but the precision may vary.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of the
4、safety problems, 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:2D87 Test Method for Melting
5、Point of Petroleum Wax(Cooling Curve)D 127 Test Method for Drop Melting Point of PetroleumWax Including PetrolatumD 938 Test Method for Congealing Point of PetroleumWaxes Including PetrolatumE1 Specification for ASTM Thermometers3. Terminology3.1 Definitions: Related to This Standard:3.2 solidificat
6、ion point of petroleum waxthat temperaturein the cooling curve of the wax where the slope of the curvefirst changes significantly as the wax sample changes from aliquid to a solid state.4. Summary of Test Method4.1 A 50-mg sample of wax is placed in a test tube atambient temperature and heated above
7、 the solidification pointof the wax sample. A thermocouple probe, attached to arecorder, is inserted into the wax sample, which is allowed tocool at room temperature. The thermocouple response of thecooling wax traces a curve on the chart paper of the recorder.The first significant change in the slo
8、pe of the curve is thesolidification point.5. Significance and Use5.1 The related methods of determining the melt point ofpetroleum wax are relatively time-consuming. This methodendeavors to reduce the duration of testing significantly and atthe same time maintain a reasonable precision. This method
9、can be useful for quality control of petroleum waxes as well asresearch and product development work on these waxes.5.2 For methods used for testing melt points of petroleumwaxes, see Tests Method D 87, D 127, including Petrolatumand Test Method D 938.6. Apparatus6.1 Thermocouple, with an iron-const
10、antan junction.36.2 Recorder capable of recording voltage and equippedwith a time-base module. The recorder should have thefollowing minimum specifications:6.2.1 Span, 0 to 10 mV or other suitable ranges.6.2.2 Accuracy, 0.25 % of full scale.6.2.3 Step Response Time, 1-s full scale, 3-s full scale is
11、 alsoappropriate.6.2.4 Zero Junction/Reference Junction/Temperature Com-pensated JunctionMust be included.6.3 TFE-Fluorocarbon Holder AdapterSee Fig. 1 andFig. 2.46.4 TFE-Fluorocarbon Disk Centering GuideSee Fig. 1and Fig. 2.46.5 Test Tubes, 6 by 50-mm.6.6 Vial, 25 by 52-mm.1This test method is unde
12、r the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.10 on Properties of Petroleum Wax (Joint ASTM TAPPI).Current edition approved May 1, 2005. Published May 2005. Originallyapproved in 1980. Last previous edition approved i
13、n 2000 as D 3944 88 (2000).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 Document Summary page onthe ASTM website.3Suitable thermocouples are availa
14、ble from: Claud S. Gordon Co., 5710Kenosha St., Richmond, IL 60071, (815) 678-2211. For “J” (iron-constantan)junction the following is suitable: Xactpak Type MM Assembly, Catalog No.402-1101.Junction: grounded (G)Transition fitting: TH 2780-020Thermocouple wire: J30-1-305L (length of metal sheath)E
15、(lead length): specify length desired.4Not commercially available and hence must be made in a machine shop orelsewhere.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.7 Apparatus for Calibrating Temperature Recorder:6.7.1 Stainless
16、 Steel Beaker, 1000-mL.6.7.2 Heating Mantle,tofit6.7.1.6.7.3 Autotransformer to control heat to 6.7.2.6.7.4 Variable-Speed-Stirrer.6.7.5 Thermometer, ASTM No. 61C or 61F, 79-mm immer-sion.6.8 Methods for Heating Specimen:6.8.1 Hot Air Blower at 1000 W, 1200 W, or other suitablepower. This could be a
17、 laboratory or a household hair dryertype.6.8.2 Aluminum Heating Block, about 50 by 50 by 50 mm.In the center of one face of the block, a hole is made 7 mm indiameter and 37 mm deep to accommodatea6by50-mm testtube and another hole adjacent to it to accommodate a 110-V,30-W cartridge heater, about 9
18、 by 38 mm, commerciallyavailable (see Fig. 2).6.8.2.1 Autotransformer, to control heat in 6.8.2.7. Procedure7.1 Calibrate the recorder at least every 60 days when infrequent use (see Annex A1).7.2 Obtain a wax sample representative of the material to betested.7.3 Using a balance accurate to at least
19、 1 mg, weight 50 + 5mg of sample by putting a few tiny pieces of solid wax into atared 6- by 50-mm test tube.FIG. 1 Solidification Point ApparatusFIG. 2 Apparatus for Heating Wax SampleD 3944 88 (2005)27.4 Start the temperature recorder.Ahorizontal pen speed ofabout 150 mm (5 in.)/10 min for a X-Y r
20、ecorder or a chart speedof about 150 mm (5 in.)/10 min for a strip chart recorder isusually appropriate.7.5 Heat the sample by any convenient method, such as byuse of:7.5.1 A hot air blower.7.5.2 An aluminum heating block.7.6 When using any method of heating a sample, note thatthe wax absorbs heat s
21、lowly. Hence caution must be used notto overheat the surface near the heating medium. Overheatedwax can degrade. A minute amount of degradation affectsresults.7.7 When the sample melts, insert the thermocouple probeinto the melted wax.7.8 Let the wax sample temperature rise 10 to 15C abovethe expect
22、ed solidification point.7.9 Transfer the 6- by 50-mm test tube, together with itsheated specimen, from the heating medium to a 25- by 52-mmvial which acts as a cooling chamber (See Fig. 1).7.10 Let the specimen cool until the curve traced by thecooling wax on the recorder chart paper levels off.7.11
23、 Determine the point in the curve which shows the firstsignificant change in the slope of the curve (see Fig. 3). This isthe solidification point.8. Report8.1 Report the solidification point to the nearest 0.1C.9. Precision and Bias59.1 The precision of this test method as determined bystatistical e
24、xamination of interlaboratory results is as follows:9.1.1 RepeatabilityThe difference between two test re-sults, obtained by the same operator with the same apparatusunder constant operating conditions on identical material,would in the long run, in the normal and correct operation ofthe test method
25、, exceed the following values only in one casein twenty:Distillate waxes 0.6 C (1.0 F)Residual waxes 0.7 C (1.3 F)9.1.2 ReproducibilityThe difference between two singleand independent results obtained by different operators work-ing in different laboratories on identical test material would, inthe l
26、ong run, in the normal and correct operation of the testmethod, exceed the following values only in one case intwenty:Distillate waxes 1.2 C (2.2 F)Residual waxes 2.4 C (4.3 F)9.2 The precision data were obtained in an interlaboratorystudy involving five laboratories in which solidification pointsof
27、 five distillate waxes (51 to 69 C/123 to 155 F) and fiveresidual waxes (53 to 85 C/128 to 185 F) were determined.9.3 BiasThe procedure in this test method has no biasbecause the value of solidification point can be defined only interms of a test method.10. Keywords10.1 petroleum wax; solidification
28、 print; wax5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D02-1133.FIG. 3 A Typical CurveD 3944 88 (2005)3ANNEX(Mandatory Information)A1. CALIBRATION OF RECORDERA1.1 Set up a calibration assembly consisting of a 1000mL-beaker,
29、 with the thermocouple probe suspended in thecenter and with a thermometer suspended in a closely adjacentposition at the proper immersion level. The thermometershould have a range as shown below and conform to therequirements as prescribed in Specification E1, or in Specifi-cations for IP Standard
30、Thermometers:Thermometer Range Thermometer Number32 to 127C90 to 260F61C61FA1.2 Place hot water which is near boiling at about 95C inthe beaker and stir thoroughly with a variable speed stirrer.Start the recorder. As the water cools, record the exactthermometer reading and the recorder pen reading (
31、in milli-volts), taking a series of readings at intervals of even 5C onthe thermometer until the bath cools to 50C.A1.3 Plot a calibration curve, showing the pen reading onthe abscissa (X-axis) and the corrected value (certified ther-mometer readings) on the ordinate (Y-axis). Use this plot forobtai
32、ning corrected solidification points.ASTM 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 rights, and the ri
33、skof 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 for revision of th
34、is 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
35、 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).D 3944 88 (2005)4
