1、Designation: D1525 09Standard Test Method forVicat Softening Temperature of Plastics1This standard is issued under the fixed designation D1525; 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
2、parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method covers determination of the tempera-ture at whi
3、ch a specified needle penetration occurs whenspecimens are subjected to specified controlled test conditions.1.2 This test method is not recommended for ethyl cellu-lose, nonrigid poly(vinyl chloride), poly(vinylidene chloride),or other materials having a wide Vicat softening range.1.3 The values st
4、ated in SI units are to be regarded asstandard.1.4 Due to the potential safety and environmental hazardsassociated with mercury-filled thermometers, the use of alter-native temperature measuring devices (such as thermocouplesand RTDs) is encouraged.1.5 This standard does not purport to address all o
5、f 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 limitations prior to use.NOTE 1This test method is equivalent to ISO 306 in all sections wi
6、ththe exceptions of the allowance for creep, prior to the beginning of the testand the allowance of the fluidized powder as a heat transfer medium.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD1898 Practice for Sam
7、pling of Plastics3E1 Specification for ASTM Liquid-in-Glass ThermometersE77 Test Method for Inspection and Verification of Ther-mometersE608/E608M Specification for Mineral-Insulated, Metal-Sheathed Base Metal ThermocouplesE691 Practice for Conducting an Interlaboratory Study toDetermine the Precisi
8、on of a Test MethodE1137/E1137M Specification for Industrial Platinum Resis-tance Thermometers2.2 ISO Standards:4ISO 306 PlasticsThermoplastic MaterialDeterminationof Vicat Softening Temperature3. Terminology3.1 DefinitionsDefinitions of plastics used in this testmethod are in accordance with those
9、defined in TerminologyD883, unless otherwise specified.3.1.1 Vicat softening temperaturethe temperature atwhich a flat-ended needle of 1-mm2circular cross section willpenetrate a thermoplastic specimen to a depth of 1 mm undera specified load using a selected uniform rate of temperaturerise.4. Summa
10、ry of Test Method4.1 A flat-ended needle loaded with a specified mass isplaced in direct contact with a test specimen. The mass appliedcan be one of two accepted loads, as follows:Loading 110 6 0.2 NLoading 250 6 1.0 NThe specimen and needle are heated at either of two permis-sible rates, as follows
11、:Rate A50 6 5C/hRate B120 6 10C/hThe temperature at which the needle has penetrated to a depthof 1 6 0.01 mm is recorded as the Vicat softening temperature.5. Significance and Use5.1 Data obtained by this test method is used to compare theheat-softening qualities of thermoplastic materials.1This tes
12、t method is under the jurisdiction ofASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.30 on Thermal Properties(Section D20.30.07).Current edition approved Nov. 15, 2009. Published December 2009. Originallyapproved in 1958. Last previous edition approved in 2007 as D
13、1525 - 07. DOI:10.1520/D1525-09.2For 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.3Withdrawn.4Available from Am
14、erican National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2 This test method is useful in the areas of quality control,development,
15、and characterization of plastic materials.6. Apparatus6.1 The instrument shall have a heating system consisting ofa heated bath (see Fig. 1) or a contact heating system (see Fig.2):The equipment shall be constructed essentially as shown inand shall consist of the following:6.1.1 Immersion BathAn imm
16、ersion bath containing theheat-transfer medium shall be equipped with an agitationsystem, temperature-measuring device, and heater. The heatershall have automatic control of the selected bath temperature-rise rate (see 4.1). The bath should be constructed to allow thespecimens to be submerged at lea
17、st 35 mm below the surfaceof the heat-transfer medium.6.1.1.1 Heat-Transfer MediumShall be a liquid or fluid-ized powder.5Several liquids, such as silicone oils, glycerine,ethylene glycol, and mineral oil have been used successfullyfor various plastics.6The medium used shall be free fromcontaminants
18、 and shall have no short-time effect at elevatedtemperatures on the material being tested, liquid mediums shallbe of low viscosity at room temperature. The results of the testsome times depend on the thermal diffusivity of the heat-transfer medium.6.1.2 Contact Heating UnitShall consist of heater an
19、dheater blocks which, through conductive heating, raises thetemperature of the specimen at the required controlled rateuntil the VICAT Softening Temperature is reached.NOTE 2It is desirable to have a method of cooling the bath or heatedblocks in order to reduce the time required to lower the tempera
20、ture of thebath between tests. This may be accomplished by using a cooling coilinstalled in the bath or an external heat-transfer system. If the temperaturerise rate is adversely affected by the presence of residual coolant in thecooling coils, the coolant should be purged prior to beginning the tes
21、t.5Aluminum Oxide has been found satisfactory and safe for short-term heatcycles up to 500C.6Silicone oils having a room temperature viscosity of 100 cP have been foundsatisfactory and safe for short-term heat cycles up to 260C.FIG. 1 Apparatus for Softening Temperature Determination (Immersion Bath
22、)Key1 Weight2 Displacement-measurement device3 Heater(s) (Note that multiple heaters are placed symmetricallythroughout the instrument and not just in the one location shown.)4 Heating block (contains lower contact plate)5 Load rod with needle6 Temperature-measuring device7 Test specimen8 Contact pl
23、ateFIG. 2 Apparatus for Softening Temperature Determination(Direct Contact)D1525 0926.1.3 Specimen SupportAsuitable stand or support for thespecimen to be placed in the bath or be part of the contactheating structure. The vertical members that attach the speci-men support to the upper plate shall be
24、 made of a materialhaving the same coefficient of expansion as that used for therod through which the load is applied in order that thepenetration-measuring device reading caused by differentialexpansion over the intended temperature range does not exceed0.02 mm when the specimen is replaced by a pi
25、ece ofheat-resistant material.76.1.4 Penetration-Measuring DeviceThe device used formeasuring the penetration of the specimen shall be capable ofmeasuring a penetration depth of at least 1 6 0.01 mm. Themeasuring device shall be an analog or digital dial gauge orsimilar device, including an electron
26、ic-displacement sensingapparatus.6.1.5 MassesA set of masses of suitable sizes shall besupplied so that the net force on the needle point shall be equalto 10 6 0.2 N (Loading 1) or 50 6 1.0 N (Loading 2) when theapparatus is assembled. The net force shall consist of theweight of the needle rod assem
27、bly, the force attributed to actionof the penetration-measuring device, and the extra weight thatis required to balance the system. The required mass iscalculated as follows:Required mass, mw5F 2 Fs!/9.80665 2 mrF = total force to be applied to the specimen, N,Fs= force exerted by any penetration-me
28、asuring device,N (this is a positive value if the thrust of the springis towards the specimen (downward), a negativevalue if the thrust of the spring is opposing thedescent of the rod, or zero if no such device isinvolved),mr= mass of the needle rod assembly, kg, andmw= extra mass applied to attain
29、the desired force, kg.Verification of the load should be made on new equipmentand after replacing penetration-measuring devices, or at anytime to ensure that the equipment is in calibration. Thecalibration procedure for dial-gauge-type penetration-measuring devices is described in Appendix X1 and Ap
30、pendixX2. The methods for determination of the thrust contributed bydial-gauge-type penetration-measuring devices are also givenin Appendix X1 and Appendix X2.6.1.6 Temperature-Measuring DeviceAthermocouple, re-sistance thermometer (RTD), or thermometer adequate to coverthe range being tested. The t
31、hermometer shall be one of thefollowing, or its equivalent, in accordance with SpecificationE1: Thermometer 1C or 2C, having ranges from 20 to 150Cor 5 to 300C, respectively, depending on the test range. Thethermocouple or resistance thermometer and related electronicsshall be accurate to at least 6
32、0.5C. Liquid-in-glass thermom-eters shall be calibrated for the depth of immersion in accor-dance with Test Method E77. Thermocouples shall complywith the requirements of Specification E608/E608M. Resis-tance thermometers shall comply with the requirements ofSpecification E1137/E1137M.6.1.7 NeedleA
33、flat-tipped, hardened steel needle with across-sectional area of 1.000 6 0.015 mm2(diameter of 1.120to 1.137 mm) shall be used. The tip shall be free of burrs andbe perpendicular to the axis of the rod. The needle shallprotrude at least 2 mm from the end of the rod.7. Sampling7.1 Unless otherwise ag
34、reed upon between the seller and thepurchaser, sample in accordance with the sections on GeneralSampling Procedures and Specific Sampling Procedures ofPractice D1898. Sampling based on engineering principles,prior to packaging, shall be considered an acceptable alterna-tive.8. Test Specimen8.1 Use a
35、t least two specimens to test each sample. Thespecimen shall be flat, between 3 and 6.5 mm thick, and at least10 by 10 mm in area or 10 mm in diameter. If an individuallayer of the specimen is less than 3 mm it is permissible tostack not more than three (3) layers to achieve the minimumthickness. Th
36、e specimens shall be cut from sheet or moldedmaterial. The type of mold and the molding process used toproduce test specimens will affect the results obtained in thetest. Molding conditions shall be in accordance with thestandard for the material being tested or should be agreed uponbetween the coop
37、erating laboratories.NOTE 3Discrepancies in test results due to variations in moldingconditions often are minimized by annealing the test specimens before thetest. Since different materials require different annealing conditions,annealing procedures shall be employed only if required by the material
38、standard or if agreed upon between the cooperating laboratories.9. Conditioning9.1 If conditioning of the specimens is required, the testspecimens shall be conditioned at 23 6 2C and at 50 6 10 %relative humidity for not less than 40 h in accordance withPractice D618.NOTE 4Conditioning periods less
39、than the 40 h, as specified byPractice D618, may be used when it is shown that the Vicat softeningtemperature is not affected by the shorter conditioning time. Longerconditioning times may be required for some materials that take longer toreach temperature and humidity equilibrium. Refer to the appl
40、icableASTM standards for those materials.10. Procedure10.1 Prepare the instrument so that the temperature of theheat-transfer medium or contact plates is between 20 and 23Cat the start of the test unless previous tests have shown that fora particular material under test no error is introduced bystar
41、ting at a higher temperature. The immersion bath systemshall be well agitated.NOTE 5Under certain conditions, it may be difficult to bring thetemperature of the heat-transfer medium down to 20 to 23C. In thesecases, the test may be started with the bath temperature at 30C. Theselection of the starti
42、ng temperature shall be agreed upon between thecooperating laboratories.10.2 Place the specimen, which is at room temperature, onthe specimen support so that it is approximately centered underthe needle. The needle should be at least 3 mm from the edge7Borosilicate glass or Quartz has been found sat
43、isfactory for this purpose.D1525 093of the specimen. Gently lower the needle rod, without the extramass, so that the needle rests on the surface of the specimenand holds it in position.10.3 Position the temperature measuring device so that thesensing end is located within 10 mm from where the load i
44、sapplied to the surface of the specimen. The sensing end shouldnot touch the specimen.10.4 Lower the assembly into the bath or close the contactplates, taking care not to jar it in any way that would damageor dislodge the specimen.10.5 Apply the extra mass required to increase the load onthe specime
45、n to 10 6 0.2 N (Loading 1) or 50 6 1.0 N(Loading 2). After a 5-min waiting period, set the penetrationindicator to zero.10.6 Start the temperature rise. The rate of temperatureincrease shall be either 50 6 5C/h (Rate A) or 120 6 10C/h(Rate B) and shall be uniform throughout the test. The Rate Aheat
46、ing requirement shall be considered to be met if over every12-min interval during the test, the temperature of the bath orcontact plates rises 10 6 1C at each specimen location. TheRate B heating requirement shall be considered to be met ifover every 6-min interval during the test, the temperature o
47、f thebath or contact plates rises 12 6 1C at each specimen loca-tion. The selection of the rate of rise shall be agreed uponbetween cooperating laboratories. See Annex A1 for calibra-tion of single temperature probe units.10.7 Record the temperature of the bath or contact plateswhen the needle has p
48、enetrated 1 6 0.01 mm into the testspecimen. Take care to ensure that an accurate reading of thetemperature is made since the rate of penetration of thespecimen will be increasing rapidly at this point.10.8 Express the Vicat softening temperature as the arith-metic mean of the temperature of penetra
49、tion of all specimenstested. If the range of penetration temperatures for the indi-vidual test specimens exceeds 2C, record the individualresults and repeat the test, using at least two new specimens.NOTE 6If a permanent record is desired, either read and record thepenetration for each 5C rise in temperature until the penetration reaches0.4 mm, and at 2C intervals thereafter, or attach a displacementtransducer, having the same resolution as the gauge, to each rod andcontinuously record the rate of penetration by means of a multichannelreco
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