1、Designation: D3236 88 (Reapproved 2014)Standard Test Method forApparent Viscosity of Hot Melt Adhesives and CoatingMaterials1This standard is issued under the fixed designation D3236; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、 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 This test method covers the determination of the appar-ent viscosity of hot melt adhesives and coating ma
3、terialscompounded with additives and having apparent viscosities upto 200 000 millipascal second (mPas) (Note 3) at temperaturesup to 175C (347F).NOTE 1Although precision has not been studied, this procedure maybe adaptable to viscosities higher than the present 200 000-mPas limit andtemperatures ab
4、ove 175C (347F). Equipment described in this testmethod permits testing of materials having viscosities as high as 16 106mPas and provides temperatures up to 260C (500F).NOTE 2For petroleum waxes and their blends having apparentviscosities below 15 mPas, Test Method D445 is especially applicable.NOT
5、E 3One pascal second (Pas) = 1000 centipoise (CP); one milli-pascal second = one centipoise.1.2 The values stated in SI units are to be regarded as thestandard. The values in parentheses are for information only.1.3 This standard does not purport to address all of thesafety concerns, if any, associa
6、ted 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:2D445 Test Method for Kinematic Viscosity of Transparentand O
7、paque Liquids (and Calculation of Dynamic Viscos-ity)3. Terminology3.1 Definitions:3.1.1 apparent viscositythe viscosity determined by thistest method and expressed in millipascal seconds. Its valuemay vary with the spindle and rotational speed selectedbecause many hot melts are non-Newtonian.3.1.2
8、viscositythe ratio of shear stress to shear rate. Theviscosity of a liquid is a measure of the internal friction of theliquid in motion. The unit of dynamic viscosity is the pascalsecond. For a Newtonian liquid, the viscosity is constant at allshear rates. For a non-Newtonian liquid, viscosity will
9、varydepending on shear rate.4. Summary of Test Method4.1 A representative sample of the molten material to betested is maintained in a thermally controlled sample chamber.Apparent viscosity is determined under temperature equilib-rium conditions using a precision rotating spindle type viscom-eter. D
10、ata obtained at several temperatures can be plotted onappropriate semi-logarithmic graph paper and apparent viscos-ity at intermediate temperatures can be estimated.5. Significance and Use5.1 This test method distinguishes between hot melts havingdifferent apparent viscosities. It is believed that a
11、pparentviscosity determined by this procedure is related to flowperformance in application machinery operating under condi-tions of low shear rate. Apparent viscosity as determined bythis test method may not correlate well with end-use applica-tions where high shear rates are encountered.5.2 Materia
12、ls of the type described in this procedure may bequite non-Newtonian and as such, the apparent viscosity willbe a function of shear rate under the conditions of test.Although the viscometer described in this test method gener-ally operates under conditions of relatively low shear rate,differences in
13、 shear effect can exist depending upon the spindleand rotational speed conditions selected for the test program.Maximum correlation between laboratories, therefore, dependsupon testing under conditions of equivalent shear.5.3 Approximate shear rates using various spindles areshown in Table A1.1.1Thi
14、s test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.10.0A on Physical/Chemical Properties.Current edition approved May 1, 2014. Published July 2014. Originally approvedin 1973. Last previ
15、ous edition approved in 2009 as D3236 88 (2009). DOI:10.1520/D3236-88R14.2For 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 A
16、STM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States16. Apparatus6.1 Viscometer, rotating spindle type with leveling stand.36.2 Viscometer Spindles, stainless steel.36.3 Sample Chamber, with precision proportional tempera-ture
17、controller3,4that provides control accuracy of61.0C (1.8F) or better through the range from 100 to 200C(212 to 392F).6.4 Graph Paper, semi-logarithmic.7. Calibration7.1 The viscometer is precalibrated using Newtonian fluidsby the manufacturer. No zero adjustment is provided, sinceexperience has show
18、n that the zero point will not vary due tochanges in the spring. The viscometer and spindles are preci-sion equipment and should be kept from undue shock andmishandling. Physical damage to the instrument will oftenreveal itself as erratic or no oscillation of the pointer when theinstrument, with or
19、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.7.2 The instrument may be further calibrated using standardreference fluids. Suitable fluids are available in nominalviscosities up to 15 000 mPas
20、 at 149C (300F).5The proce-dure for instrument calibration using standard reference fluidsis that encompassed by this test method. Results obtained usingstandard reference fluids should not deviate from the nominalviscosity by more than 2 %.7.3 The temperature controller of the type recommended fort
21、his procedure is factory calibrated and has control capabilityof 60.5 % of the control point (61.0C at 175C). To furthercheck the controller and further establish controller settings,use the following procedure: Place a sufficient quantity of lowviscosity (500 mPas or less) hot melt in the sample co
22、ntainerto permit immersion of the appropriate ASTM thermometer tothe proper depth. Do not permit the thermometer bulb to rest onthe bottom of the sample container. Suitable thermometers areshown in Table 1.NOTE 4Particular care must be taken not to overflow the samplechamber when using the 100C, 76-
23、mm immersion thermometer.7.3.1 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 reading to mi
24、nimize 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 betweenlaboratories, depending upon the controller, but should in nocase exceed 60.5C (0.9F). Repeat this
25、 procedure for any testtemperature desired within the scope of this test method.8. Procedure8.1 Selection of SpindleFrom the estimated viscosity ofthe sample and Table A1.1 in the Annex, select a viscometerand spindle combination that will produce readings in thedesired range.NOTE 5Use only the spin
26、dle shown to be appropriate for theviscometer to be used.8.1.1 Where more than one spindle is available for the rangeselected, choose the spindle that produces results nearest themidpoint of the measurable viscosity range. Viscometer scalereadings must be within the 10 to 95 range.NOTE 6Care must be
27、 taken in the storage and handling of spindles andassemblies. Protect them from dust, corrosive deposits, and mechanicalabuse.Avoid touching the calibrated section of the spindle with the hands.Clean the spindle and sample chamber thoroughly after each use. Arecommended cleaning procedure is include
28、d in Annex A2.8.2 Preparation of SamplePlace the required amount ofrepresentative sample (see Table 2) measured to the nearest0.005 g (or 0.05 mL if handled in the molten state) in thesample chamber. Melt the sample in an oven set at the desiredtest temperature or in the thermo-container preheated t
29、o thedesired test temperature. Avoid excessive or prolonged heatingof the sample to minimize thermal and oxidative effects. Use afresh sample for each temperature for which a determination isto be made.8.3 System Alignment and Spindle InsertionAfter thesample is completely melted, lower the properly
30、 aligned andleveled viscometer until the tips of the alignment bracket just3The sole source of supply of the viscometers and accessories known to thecommittee at this time is Brookfield Engineering Laboratories, Inc., Stoughton, MA02072. If you are aware of alternative suppliers, please provide this
31、 information toASTM International Headquarters. Your comments will receive careful consider-ation at a meeting of the responsible technical committee,1which you may attend.4The sole source of supply of the temperature controller known to the committeeat this time isAthena Controls, Inc., 2 Union Roa
32、d, West Conshohocken, PA19428.If you are aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.5The sole source of supply of the cali
33、bration fluids known to the committee atthis time is Brookfield Engineering Laboratories, Inc., Stoughton, MA 02072 orCannon Instrument Co., P. O. Box 16, State College, PA 16801. If you are aware ofalternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your commen
34、ts will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.TABLE 1 Suitable ASTM ThermometersTemperature RangeImmersion,mmScaleError,maxASTM ThermometerNumber90C to 170C 51 0.2C 35C-62194F to 338F 51 0.5F 35F-62145C to 205C 76 0.4C 100C-68TABLE 2 S
35、ample Size RequirementSpindleApproximateVolume, mLApproximate SampleWeight, gASC 4-18 8.00 6.40SC 4-21 8.00 6.40SC 4-27 10.50 8.40SC 4-28 11.50 9.20SC 4-29 13.00 10.40SC 4-31 10.00 8.00SC 4-34 9.50 7.60ABased on typical molten specific gravity of 0.800. If the specific gravity of thematerial to be t
36、ested varies greatly from this value, sample size must be adjustedto ensure proper liquid level on the spindle shaft.D3236 88 (2014)2touch the top of the thermo-container, making contact directlybehind the locating ring. Raise the viscometer, positioning thetips of the alignment bracket 2 mm (116 in
37、.) above the top ofthe thermo-container. Using both hands, gently slide thethermo-container base until the tips of the alignment bracketjust touch the locating ring. Do not forcibly displace thealignment bracket (see Fig. 1). Screw the link coupling nutonto the viscometer coupling nut (note left-han
38、d thread).Connect the coupling link to the spindle (and the coupling nut).Lower the spindle into the sample chamber and connect thelink coupling nut to the viscometer coupling nut, noting theleft-hand thread. Pick up the insulating cap and place it overthe sample chamber (see Fig. 1).8.4 Viscosity D
39、eterminationEnsure that the material in thesample chamber is completely molten and that temperaturecontroller settings are proper. Turn on the viscometer and allowthe spindle to rotate at the lowest spindle speed available tominimize temperature gradients in the sample as well aspossible shear effec
40、ts. When temperature equilibrium isindicated, turn off the viscometer, remove the insulating cap,raise the viscometer and spindle, and inspect the liquid level onthe spindle shaft. It should extend about 3 mm (18 in.) up thespindle shaft beyond the upper, tapered portion of the spindle.If the liquid
41、 level varies significantly from this, add or removesample to provide this level. Replace the insulating cap, andallow the unit to reestablish temperature equilibrium with thespindle rotating at the lowest available speed. Continue spindlerotation for 15 min after apparent equilibrium. Increase thes
42、pindle speed to that required to produce a scale readingnearest the midpoint of the scale, but in no case outside the 10to 95-unit range. Engage the pointer clutch and stop theviscometer motor when the pointer is in view. Record the scaleFIG. 1 Apparatus for Viscosity DeterminationD3236 88 (2014)3re
43、ading. Restart the viscometer motor, and allow at least fiveadditional revolutions of the spindle. Engage the pointer clutchand stop the viscometer motor with the pointer in view. Recordthe second dial reading. Repeat the above operation until threeconsecutive scale readings are obtained that differ
44、 by no morethan 0.5 unit.9. Calculation9.1 Determine the average of the three consecutive scalereadings which differ by no more than 0.5 scale unit. Toconvert to millipascal seconds, multiply this value by theappropriate factor taken from either the instrument instructionmanual or Table A1.2. Repeat
45、 this for each temperature.NOTE 7If it is necessary to interpolate for viscosity values atintermediate temperatures, plot a series of observed apparent viscosityvalues on the logarithmic scale and the corresponding test temperatures onthe linear scale of appropriate semi-logarithmic paper, using a s
46、eries of atleast three different temperatures. From the plot, determine the apparentviscosity at any temperature requested, within the range of test tempera-tures.10. Report10.1 Report the apparent viscosity at a given temperaturealong with the particulars of the instrument model, the spindlenumber
47、and rotational speed. Example: Apparent viscosity at125C (RVT, SC 4-28, 20 rpm)20 000 mPas.NOTE 8If it is desired to report the shear rate corresponding to theinstrument/spindle/speed combination, refer to Table A1.1 for the appro-priate calculation.11. Precision and Bias11.1 The precision of this t
48、est method as determined bystatistical examination of interlaboratory results is as follows:11.1.1 RepeatabilityThe difference between two testresults, obtained by the same operator with the same appa-rataus under constant operating conditions on identical testmaterial would, in the normal and corre
49、ct operation of the testmethod, exceed the following values in one case in twenty:8.8% of the mean of the two results. (1)11.1.2 ReproducibilityThe difference between two singleand independent results obtained by different operators work-ing in different laboratories in identical test material would, inthe long run, exceed the following value only in one case intwenty:25.4% of the mean of the two results. (2)NOTE 9The precision of this test method is based on a round-robinconducted using six wax-based hot melt materials that
