1、Designation: D3236 88 (Reapproved 2014)D3236 15Standard 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 r
2、evision, 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. Scope Scope*1.1 This test method covers the determination of the apparent viscosity of hot melt adhesives
3、and coating materials compoundedwith additives and having apparent viscosities up to 200 000 millipascal second (mPas) (Note 3) at temperatures up to 175C(347F).175 C (347 F).NOTE 1Although precision has not been studied, this procedure may be adaptable to viscosities higher than the present 200 000
4、-mPas200 000 mPaslimit and temperatures above 175C (347F).175 C (347 F). Equipment described in this test method permits testing of materials having viscosities ashigh as 16 106 mPas and provides temperatures up to 260C (500F).260 C (500 F).NOTE 2For petroleum waxes and their blends having apparent
5、viscosities below 15 mPas, Test Method D445 is especially applicable.NOTE 3One pascal second (Pas) = 1000 centipoise (CP);(cP); one millipascal second = one millipascal-second = one centipoise.1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for inf
6、ormation only.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2.
7、Referenced Documents2.1 ASTM Standards:2D445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)3. Terminology3.1 Definitions:3.1.1 apparent viscositythe viscosity determined by this test method and expressed in millipascal seconds. Its value
8、may varywith the spindle and rotational speed selected because many hot melts are non-Newtonian.3.1.2 viscositythe ratio of shear stress to shear rate. The viscosity of a liquid is a measure of the internal friction of the liquidin motion. The unit of dynamic viscosity is the pascal second. For a Ne
9、wtonian liquid, the viscosity is constant at all shear rates.For a non-Newtonian liquid, viscosity will vary depending on shear rate.4. Summary of Test Method4.1 A representative sample of the molten material to be tested is maintained in a thermally controlled sample chamber.Apparent viscosity is d
10、etermined under temperature equilibrium conditions using a precision rotating spindle type viscometer. Dataobtained at several temperatures can be plotted on appropriate semi-logarithmic graph paper and apparent viscosity at intermediatetemperatures can be estimated.5. Significance and Use5.1 This t
11、est method distinguishes between hot melts having different apparent viscosities. It is believed that apparent viscositydetermined by this procedure is related to flow performance in application machinery operating under conditions of low shear rate.Apparent viscosity as determined by this test meth
12、od may not correlate well with end-use applications where high shear rates areencountered.1 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.10.0A on Physical/Chemical Properties.Cu
13、rrent edition approved May 1, 2014April 1, 2015. Published July 2014May 2015. Originally approved in 1973. Last previous edition approved in 20092014 asD3236 88 (2009).(2014). DOI: 10.1520/D3236-88R14.10.1520/D3236-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactAST
14、M Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made
15、 to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Su
16、mmary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.2 Materials of the type described in this procedure may be quite non-Newtonian and as such, the apparent viscosity will bea
17、function of shear rate under the conditions of test.Although the viscometer described in this test method generally operates underconditions of relatively low shear rate, differences in shear effect can exist depending upon the spindle and rotational speedconditions selected for the test program. Ma
18、ximum correlation between laboratories, therefore, depends upon testing underconditions of equivalent shear.5.3 Approximate shear rates using various spindles are shown in Table A1.1.6. Apparatus6.1 Viscometer, Concentric Cylinder Rotationalrotating spindle type with leveling stand.The essential ins
19、trumentationrequired providing the minimum rational viscometer analytical capabilities include:6.1.1 Drive motor, to apply a unidirectional rotational displacement to the specimen at a rate of 0.5 rmin to 60 rmin constantto 61 %.6.1.2 Force sensor, to measure the torque developed by the specimen in
20、response to the rotational displacement.6.1.3 Coupling shaft, or other means to transmit the rotational displacement from the motor to the specimen.NOTE 4It is helpful to have a mark on the shaft to indicate appropriate test fluid level.6.1.4 Stainless steel rotational element, spindle, or tool, for
21、 the type shown in Fig. 1 to fix the specimen between the draft shaftand a stationary position.6.1.5 Data collection device, to provide a means of acquiring, storing, and displaying measured or calculated signals, or both.The minimum output signals required for rotational viscometry are torque, rota
22、tional speed, temperature, and time.NOTE 5Manual observation and recording of data are acceptable.6.1.6 Temperature measuring device, to provide an indication of the specimen temperature over their range of 100 C to 200C to within 60.2 C.6.1.7 Stand, to support, level, and adjust the height of the d
23、rive motor, shaft and rotational element.6.1.8 Specimen container, fitted with an insulated cover, to contain the test specimen during testing.6.1.9 Auxiliary instrumentation considered necessary or useful in conducting this method includes:6.1.9.1 Data analysis capability to provide viscosity, stre
24、ss, or other useful parameters derived from measured signals.6.1.9.2 Level to indicate the vertical plumb of the drive motor, shaft, and rotational element.6.1.9.3 A guard to protect the rotational element from mechanical damage.6.2 Viscometer Spindles, stainless steel.36.2 Sample Chamber,Temperatur
25、e Bath with and precision proportional temperature controller3, that provides control accuracyof 61.0C (1.8F) or better through the range from 100 to 200C (212 to 392F). a controlled isothermal temperature environmentover the range of 100 C to 200 C (212 F to 392 F) constant to accuracy of 61.0 C (1
26、.8 F).6.3 Graph Paper,paper, semi-logarithmic.7. Calibration7.1 The viscometer is precalibrated using Newtonian fluids by the manufacturer. No zero adjustment is provided, sinceexperience has shown that the zero point will not vary due to changes in the spring. torque sensor. The viscometer and spin
27、dlesare precision equipment and should be kept from undue shock and mishandling. Physical damage to the instrument will oftenreveal itself as erratic torque indication or no oscillation of the pointershaft when the instrument, with or without the spindle inplace, is operated in air. When operating n
28、ormally, the pointer torque indication will be stable and have free oscillation about thezero point in air.7.2 The instrument may be further calibrated using standard reference fluids. Suitable fluids are available in nominal viscositiesup to 15 000 mPas at 149C (300F).15 000 mPas at 149 C (300 F).4
29、 The procedure for instrument calibration using standardreference fluids is that encompassed by this test method. Results obtained using standard reference fluids should not deviate fromthe nominal viscosity by more than 2 %.7.3 The temperature controller of the type recommended for this procedure i
30、s factory calibrated and has control capability of60.5 % of the control point (61.0C at 175C). To further check the controller and further establish controller settings, use the3 The sole source of supply of the viscometers and accessories known to the committee at this time is Brookfield Engineerin
31、g Laboratories, Inc., Stoughton, MA 02072.If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consideration at a meetingof the responsible technical committee,1 which you may attend.3 The sole source of supp
32、ly of the temperature controller known to the committee at this time isAthena Controls, Inc., 2 Union Road,Rd., West Conshohocken, PA19428.If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consideration at
33、 a meetingof the responsible technical committee,1 which you may attend.4 The sole source of supply of the calibration fluids known to the committee at this time is Brookfield Engineering Laboratories, Inc., Stoughton, MA 02072 or CannonInstrument Co., P. O. Box 16, State College, PA 16801. If you a
34、re aware of alternative suppliers, please provide this information to ASTM International Headquarters. Yourcomments will receive careful consideration at a meeting of the responsible technical committee,1 which you may attend.D3236 152following procedure: Place a sufficient quantity of low viscosity
35、 (500 mPas (500 mPas or less) hot melt in the sample containerto permit immersion of the appropriate ASTM thermometer to the proper depth. Do not permit the thermometer bulb to rest onthe bottom of the sample container. Suitable thermometers are shown in Table 1.NOTE 6Particular care must be taken n
36、ot to overflow the sample chamber when using the 100C, 76-mm immersion thermometer.Do not permit thetemperature sensor to rest on the bottom of the sample container.7.3.1 Insert the thermometer temperature sensor through the insulating cover of the sample container and hold it in place at thepoint r
37、equired for proper immersion depth. Adjust the thermal controller to provide the desired test temperature. Rotate thethermometer temperature sensor during temperature reading to minimize the effect of thermal gradients in the sample. Continuetemperature readings and controller adjustment until minim
38、um deviation from test temperature is obtained. Minimum deviationmay vary between laboratories, depending upon the controller, but should in no case exceed 60.5C (0.9F).60.5 C (0.9 F).Repeat this procedure for any test temperature desired within the scope of this test method.8. Procedure8.1 Selectio
39、n of SpindleThe measurement range of the rotational viscometer is determined by the dimensions of the spindle,the rotational speed, the size and shape of the container and the full scale range of the motor. From the estimated viscosity of theFIG. 1 Apparatus for Viscosity DeterminationSpindle Config
40、urationD3236 153sample and Tablethe A1.1 in the Annex, operations manual for the viscometer, select a viscometerspindle and spindle rotationalspeed combination that will produce readings in the desired range.NOTE 7Use only the spindle shown to be appropriate for the viscometer to be used.8.1.1 Where
41、 more than one spindle is available for the range selected, choose the spindle that produces results nearest themidpoint of the measurable viscosity range. Viscometer torque scale readings mustshall be within the 1010 % to 9595 % range.NOTE 8Care must be taken in the storage and handling of spindles
42、 and assemblies. Protect them from dust, corrosive deposits, and mechanical abuse.Avoid touching the calibrated section of the spindle with the hands. Clean the spindle and sample chamber thoroughly after each use. A recommendedcleaning procedure is included in Annex A2A1.8.2 Preparation of SamplePl
43、ace Using a fresh sample for each measurement, place the required amount of representativesample (see Table 2) measured to the nearest 0.005 g (or 0.05 mL 0.005 g (or 0.05 mL if handled in the molten state) in the samplechamber.specimen container. Melt the sample in an oven set at the desired test t
44、emperature or in the thermo-container temperaturebath preheated to the desired test temperature. Avoid excessive or prolonged heating of the sample to minimize thermal andoxidative effects. Use a fresh sample for each temperature for which a determination is to be made.NOTE 9Avoid excessive or prolo
45、nged heating of the sample to minimize thermal and oxidative effects.8.3 System Alignment and Spindle InsertionAfter the sample is completely melted, lower the properly aligned and leveledviscometer until the tips of the alignment bracket just touch the top of the thermo-container, making contact di
46、rectly behind thelocating ring. Raise the viscometer, positioning the tips of the alignment bracket 2 mm (116 in.) above the top of thethermo-container. Using both hands, gently slide the thermo-container base until the tips of the alignment bracket just touch thelocating ring. Do not forcibly displ
47、ace the alignment bracket (see Fig. 1). Screw the link coupling nut onto the viscometer couplingnut (note left-hand thread). Connect the coupling link to the spindle (and the coupling nut). Lower the spindle into the samplechamber and connect the link coupling nut to the viscometer coupling nut, not
48、ing the left-hand thread. Pick up the insulating capand place it over the sample chamber (see spindle into the specimen container. Place the insulating cap over the specimencontainer.Fig. 1).8.4 Viscosity DeterminationDetermination: Ensure that the material in the sample chamber is completely molten
49、 and thattemperature controller settings are proper. Turn on the viscometer and allow the spindle to rotate at the lowest spindle speedavailable to minimize temperature gradients in the sample as well as possible shear effects. When temperature equilibrium isindicated, turn off the viscometer, remove the insulating cap, raise the viscometer and spindle, and inspect the liquid level on thespindle shaft. It should extend about 3 mm (18 in.) up the spindle shaft beyond the upper, tapered portion of the spindle. If
