1、Designation: D3954 15Standard Test Method forDropping Point of Waxes1This standard is issued under the fixed designation D3954; 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 parentheses indi
2、cates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the ASTMdropping point for waxes.1.2 The values stated in SI units are to be regarded asstandard. No other units of
3、measurement are included in thisstandard.1.3 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
4、 limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D566 Test Method for Dropping Point of Lubricating Grease3. Summary of Test Method3.1 In this test method, the dropping point is defined as thetemperature at which the wax suspended in a cylindrical cup,with a 2.8-mm diameter hole
5、in the bottom, flows downward adistance of 19 mm to interrupt a light beam as the sample isheated at a constant rate in air.4. Significance and Use4.1 Waxes do not go through a sharp solid-liquid phasechange when heated and therefore do not have a true meltingpoint. As the temperature rises, waxes g
6、radually soften orbecome less viscous. For this reason, the determination of thesoftening point must be made by an arbitrary but closelydefined method if test values are to be reproducible.4.2 This test is useful in determining the consistency ofwaxes, and as one element in establishing the uniformi
7、ty ofshipments or source of supply.4.3 This test method has been found suitable for all types ofwaxes including paraffin, microcrystalline polyethylene, andnatural waxes.5. Apparatus5.1 Suitable apparatus that meets the requirements of 5.1.1,5.1.2, and 5.1.3 can be used to determine dropping points
8、bythis test method. Instruments are available commercially3consisting of a control unit with a digital temperature recorder,matched furnace, sample cartridges, and accessories. Thecontrol unit automatically maintains the furnace temperatureand controls the heating rate with a precision of 0.1C. Thed
9、ropping point is automatically recorded, and the furnaceheating program is turned off when the sample interrupts thelight beam and triggers the photocell detector.5.1.1 Control UnitThis unit shall provide a continuouslinear temperature control from 25 to 250C at a 2C/min rate.A digital readout shall
10、 record the softening point with anaccuracy of 0.1C.5.1.2 Furnace UnitThis unit shall be capable of heating asample cup assembly as described in 5.1.3 at 2C 6 0.3C/minlinear rate from 25 to 250C. It shall include a sensing systemcapable of detecting the softening point with an accuracy of0.1C.5.1.3
11、Sample Cup AssemblyA chromium-plated brass cupconforming to the dimensions shown in Test Method D566.Itshall be placed in an assembly so that the sample flows downa distance of 19 mm to interrupt a light beam to cause digitaldisplay of the softening point.6. Preparation of Sample6.1 For waxes heat t
12、he sample to 15 to 20C above itsmelting point to form a pourable liquid. Place the sample cupson glass slides and pour the melted sample into the cup to alevel even with the upper rim of the cup. Allow the sample tostand at room temperature for 2 h before running.1This test method is under the juris
13、diction ofASTM Committee D21 on Polishesand is the direct responsibility of Subcommittee D21.02 on Raw MaterialsCurrent edition approved Oct. 1, 2015. Published October 2015. Originallyapproved in 1980. Last previous edition approved in 2010 as D3954 94 (2010).DOI: 10.1520/D3954-15.2For referenced A
14、STM 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.3To the knowledge of the committee at this time, the only instruments whichsat
15、isfy the requirements of 5.1.1, 5.1.2, and 5.1.3 are Mettler-Toledo model DP70and model DP90 fitted with FP83HT sample cup. These are available fromMettler-Toledo, LLC, 1900 Polaris Parkway, Columbus, OH 43240, .If you are aware of alternative suppliers, please provide this information to ASTMIntern
16、ational Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States17. Preparation of Apparatus7.1 Ensure that
17、 the furnace unit and the sample cup assem-bly are clean and bright, since tarnished or dirty apparatus willchange the apparent dropping point. After each determination,check to see if the apparatus requires cleaning.NOTE 1It is advisable to keep the equipment covered when not in use.8. Procedure8.1
18、 The procedure for measuring the dropping point ofwaxes with the Mettler instrument has been developed toduplicate the results obtained by Test Method D566.8.2 Preheat or cool the furnace unit to a temperature of 20 to25C less than the expected dropping point (Note 2)ofthesample and maintain at this
19、 temperature. Place the cartridgeassembly containing the sample in position in the furnace,taking care that the slits for the light beam are properlypositioned. When the ready light becomes steady, indicatingthe sample and furnace have equilibrated at the presenttemperature, initiate the 2C/min heat
20、ing rate by pressing theSTART LEVEL. Heating will then continue automatically untilthe drop point occurs and the dropping point temperature isdisplayed on the digital readout.NOTE 2In the event of a dispute, the purchaser and the seller shouldagree on the exact starting temperature to be used.8.3 Im
21、mediately remove the cartridge assembly uponcompletion of the test. Check to determine if the sample haspassed the light beam slot and no pretrigger has occurred.Inspect the dropping point apparatus to be sure no dirt,particles, or residue remain.8.4 Clean the sample cups by placing them upside down
22、 ona hard surface and punching out the residue material. Use aspatula shaped to the contours of the cup, to remove theremaining particles with a gentle twirling motion.9. Report9.1 Report the dropping point recorded on the digitalreadout to the nearest 0.1C. If converted to degreesFahrenheit, report
23、 to the nearest 0.2F. Experience has indi-cated that duplicate runs are not necessary. If a known error inexperimental procedure is made, the result should be discardedand a second run should be made.10. Precision10.1 The following criteria shall be used for judging theacceptability of results (95 %
24、 probability) for the Mettlerdropping point:10.1.1 RepeatabilityDuplicate results by the same opera-tor shall not be considered suspect unless they differ by morethan 0.5C.10.1.2 ReproducibilityThe results reported by each of twolaboratories shall not be considered suspect unless the reportedvalues
25、differ by more than 1.5C.10.1.3 The procedure in this test method has no bias becausethe values derived for the drop point of waxes are defined onlyin terms of this test method.11. Keywords11.1 drop point; waxesASTM International takes no position respecting the validity of any patent rights asserte
26、d 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 riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by th
27、e 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 this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive
28、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 shown below.This standard is copyrighted by ASTM Internat
29、ional, 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). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 152
