1、Designation: D1986 91 (Reapproved 2012)Standard Test Method forDetermining the Apparent Viscosity of Polyethylene Wax1This standard is issued under the fixed designation D1986; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar 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 This test method covers the determination of the viscos-ity in centipoise of polyethylene wax using the Brookfie
3、ld LVTor LVF viscometer and thermosel system.1.2 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 regula
4、tory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E1 Specification for ASTM Liquid-in-Glass Thermometers3. Terminology3.1 Definitions:3.1.1 polyethylene waxpolymerized ethylene with a mo-lecular weight 2,000 to 10,000 and a density of 0.9 to 1.0 g/cm3. These polymers can be ox
5、idized or copolymerized but shouldhave a melt point lower than 140C.3.1.2 viscositythe ratio of shear stress to shear rate. Theviscosity of a liquid is a measure of the internal friction of theliquid in motion. The units of viscosity is the pascal second.For a Newtonian liquid, the viscosity is cons
6、tant at all shearrates. For a non-Newtonian liquid, viscosity will vary depend-ing on shear rate.3.1.3 apparent viscositythe viscosity determined by thistest method and expressed in millipascal seconds. Its valuemay vary with the spindle and rotational speed selectedbecause many waxes are non-Newton
7、ian.4. Significance and Use4.1 This test method is used to determine a physicalproperty of a wax and may determine the utility of the wax, aswell as being a significant quality control test.5. Apparatus5.1 Brookfield Thermosel System, with LVT, LVF, or LVD111 viscometer and SC 4-31 spindle.36. Calib
8、ration6.1 The viscometer is precalibrated using Newtonian fluidsprovided by the manufacturer. No zero adjustment is providedsince experience has shown that the zero point will not varydue to changes in the spring. The viscometer and spindles areprecision equipment and should be kept from undue shock
9、 andmishandling. Physical damage to the instrument will oftenreveal itself as erratic or no oscillation of the pointer when theinstrument, with or without the spindle in place, is operated inair. When operating normally, the pointer will be stable andhave free oscillation about the zero point in air
10、.6.2 The instrument may be further calibrated using standardreference fluids. Suitable fluids are available in nominalviscosities up to 15 000 mPas at 149C (300F).3The proce-dure for instrument calibration using standard reference fluidsis not encompassed by this test method. Results obtained usings
11、tandard reference fluids should not deviate from the nominalviscosity by more than 2 %.6.3 The temperature controller of the type recommended forthis procedure is factory calibrated and has control capabilityof 60.5 % of the control point (61.0C at 175C). To furthercheck the controller and further e
12、stablish controller settings,use the following procedure. Place a sufficient quantity ofpolyethylene wax in the sample container to permit immersionof the appropriate ASTM thermometer to the proper depth. Donot permit the thermometer bulb to rest on the bottom of thesample container. Suitable thermo
13、meters are shown in Speci-fication E1.6.4 Insert the thermometer through the insulating cover ofthe sample container and hold it in place at the point requiredfor proper immersion depth. Adjust the thermal controller toprovide the desired test temperature. Rotate the thermometerduring temperature re
14、ading to minimize the effect of thermalgradients in the sample. Continue temperature readings andcontroller adjustment until minimum deviation from test tem-perature is obtained. Minimum deviation may vary between1This test method is under the jurisdiction ofASTM Committee D21 on Polishesand is the
15、direct responsibility of Subcommittee D21.02 on Raw Materials.Current edition approved Oct. 1, 2012. Published October 2012. Originallyapproved in 1991. Last previous edition approved in 2007 as D1986-91(2007). DOI:10.1520/D1986-91R12.2For referenced ASTM standards, visit the ASTM website, www.astm.
16、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.3Available from Brookfield Engineering Laboratories, Inc. 11 CommerceBoulevard, Middleboro, MA 02346.Copyright ASTM Internatio
17、nal, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1laboratories, depending upon the controller, but should in nocase exceed 60.5C (0.9F). Repeat this procedure for any testtemperature desired within the scope of this procedure.7. Procedure7.1 Use spindle number
18、31 for this test.7.2 Preparation of SamplePlace8gorapproximately 10mL of sample in the sample chamber. Melt the sample in thethermo-container preheated and set at 140C. If polyethylenewax has a melt point higher than 135C, the procedure shouldbe run at 150C. Heat for 15 min with insulating cap on sa
19、mplechamber. Avoid excessive or prolonged heating of the sampleto minimize thermal and oxidative effects.7.3 System Alignment and Spindle InsertionWith the vis-cometer raised, connect the spindle to the coupling nut (noteleft-hand thread). Lower the leveled viscometer and insert thespindle in the sa
20、mple chamber until the tips of the alignmentbracket is 2 mm (116 in.) above the top of the thermo containerand in contact with the back of the locating ring. Placeinsulating cap over the sample chamber.7.4 Turn on viscometer at the lowest RPM setting. Whentemperature equilibrium is indicated, turn o
21、ff viscometer,remove the cap, raise the viscometer and spindle and inspectthe liquid level on the spindle shaft. The liquid should extendabout 0.6 to 1.3 cm (14 to12 in.) up the spindle shaft. If theliquid level varies significantly from this, add or removesample.7.5 Lower viscometer and spindle and
22、 turn it on at thelowest RPM setting and wait for the temperatures to reachequilibrium. After equilibrium is reached, select a spindlespeed (RPM), that will produce a scale reading nearest themidpoint of the scale between 10 to 95 unit range. Allow thespindle to rotate at this speed for 15 min befor
23、e engaging thepointer clutch and stopping the motor to record the scalereadings. Restart the motor, and allow at least five additionalrevolutions before taking a reading. Repeat this operation untilthree consecutive readings differ by no more than 0.5 units.8. Calculations8.1 Convert the average of
24、these three readings to millipas-cal seconds, by multiplying this value by the appropriate factortaken from instrument instruction manual.9. Report9.1 Report the following information:9.1.1 Report the apparent viscosity at a given temperaturealong with the particulars of the instrument model, the sp
25、indlenumber and rotational speed.9.1.2 Conversion:One pascal second Pas! 5 1000 cP (1)One millipascal second mPas! 5 1 cP (2)10. Precision and Bias10.1 PrecisionDuplicate results by the same operator andusing the same model (LVT or LVF) viscometer shall not beconsidered suspect unless they differ by
26、 more than 60.3non-convert reading (95 % confidence limits for average).(This precision statement will be expanded in the future.)10.2 BiasThe procedure in this test method for measuringthe apparent viscosity of polyethylene wax has no bias becausethe value for the viscosity is defined only in terms
27、 of this testmethod.11. Keywords11.1 Brookfield viscometer; polish; polyethylene wax; ther-mosel; viscosity; waxASTM 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 advis
28、ed 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 the responsible technical committee and must be reviewed every five years andif not revised, either r
29、eapproved 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 careful consideration at a meeting of theresponsible technical committee, which you may attend. If
30、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 International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individu
31、al 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 ASTM website (www.astm.org/COPYRIGHT/).D1986 91 (2012)2
