1、Designation: D 1525 07Standard Test Method forVicat Softening Temperature of Plastics1This standard is issued under the fixed designation D 1525; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number i
2、n parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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. Scope*1.1 This test method covers determination of the tempera-ture at
3、 which 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 value
4、s stated 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 a
5、ll 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 limitations prior to use.NOTE 1This test method and ISO 306:1987(E) are technically equ
6、iva-lent, with the exception of the allowance for creep, prior to beginning thetest, in this test method.2. Referenced Documents2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 883 Terminology Relating to PlasticsD 1898 Practice for Sampling of Plastics3E1 Specification for
7、ASTM Liquid-in-Glass ThermometersE77 Test Method for Inspection and Verification of Ther-mometersE 608/E 608M Specification for Mineral-Insulated, Metal-Sheathed Base Metal ThermocouplesE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE 1137/E 1137M Sp
8、ecification for Industrial Platinum Re-sistance 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 defined in TerminologyD 883, unles
9、s 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. Summary of Test Method4.1 A flat-ended
10、 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:Rate A50 6 5C/hRate B120 6 10C/h
11、The 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 may be used tocompare the heat-softening qualities of thermoplastic materi-als.1This test method is under the jurisd
12、iction ofASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.30 on Thermal Properties(Section D20.30.07).Current edition approved March 1, 2007. Published March 2007. Originallyapproved in 1958. Last previous edition approved in 2006 as D 1525 - 06.2For referenced ASTM
13、 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 American National Standards Institute (ANSI), 25 W. 43
14、rd St.,4th Floor, New York, NY 10036.1*A Summary of Changes section appears at the end of this standard.Copyright 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, and ch
15、aracterization of plastic materials.6. Apparatus6.1 The equipment shall be constructed essentially as shownin Fig. 1 and shall consist of the following:6.1.1 Immersion BathThe bath containing the heat-transfer medium shall be equipped with a stirrer, temperature-measuring device, and heater. The hea
16、ter shall have automaticcontrol of the selected bath temperature-rise rate (see 4.1). Thebath should be constructed to allow the specimens to besubmerged at least 35 mm below the surface of the heat-transfer medium.6.1.2 Heat-Transfer MediumSeveral liquids, such as sili-cone oils, glycerine, ethylen
17、e glycol, and mineral oil have beenused successfully for various plastics.5The medium used shallbe free from contaminants and shall have no short-time effectat elevated temperatures on the material being tested, and shallbe of low viscosity at room temperature. The results of the testmay depend on t
18、he thermal diffusivity of the heat-transfermedium.NOTE 2It is desirable to have a method of cooling the bath in order toreduce the time required to lower the temperature of the bath betweentests. This may be accomplished by using a cooling coil installed in thebath or an external heat-transfer syste
19、m. If the temperature rise rate isadversely affected by the presence of residual coolant in the cooling coils,the coolant should be purged prior to beginning the test.6.1.3 Specimen SupportAsuitable stand or support for thespecimen to be placed in the bath. The vertical members thatattach the specim
20、en support to the upper plate shall be made ofa material having the same coefficient of expansion as that usedfor the rod 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
21、 when the specimen is replaced by a piece ofheat-resistant material.66.1.4 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 may be an analog or digital dial gauge ors
22、imilar device, including an electronic-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
23、of theweight of the needle rod assembly, 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=
24、 force exerted by any penetration-measuring 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,
25、andmw= extra mass applied to attain 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 device
26、s is described in Appendix X1 and Appendix5Silicone oils having a room temperature viscosity of 100 cP have been foundsatisfactory and safe for short-term heat cycles up to 260C.6Borosilicate glass has been found satisfactory for this purpose.FIG. 1 Apparatus for Softening Temperature DeterminationD
27、 1525 072X2. 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. Th
28、e thermometer 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 leas
29、t 60.5C. 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 Specicification E 608/E 608M. Resis-tance thermometers shall comply with the requirements ofSpecification E 1137/E 1137M.6.1.7
30、 NeedleA 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 oth
31、erwise agreed upon between the seller and thepurchaser, sample in accordance with the sections on GeneralSampling Procedures and Specific Sampling Procedures ofPractice D 1898. Sampling based on engineering principles,prior to packaging, shall be considered an acceptable alterna-tive.8. Test Specime
32、n8.1 Use at 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. When necessary touse multiple layers, no more than three layers of material maybe stacked in order to achieve the minimum thickness. Thesp
33、ecimens may be cut from sheet or molded material. The typeof mold and the molding process used to produce test speci-mens will affect the results obtained in the test. Moldingconditions shall be in accordance with the standard for thematerial being tested or should be agreed upon between thecooperat
34、ing laboratories.NOTE 3Discrepancies in test results due to variations in moldingconditions may be 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 materialstandar
35、d 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 5%relative humidity for not less than 40 h in accordance withPractice D 618.NOTE 4Conditioning periods less than the
36、 40 h, as specified byPractice D 618, 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 applicableA
37、STM standards for those materials.10. Procedure10.1 Prepare the immersion bath so that the temperature ofthe heat-transfer medium is between 20 and 23C at the start ofthe test unless previous tests have shown that for a particularmaterial under test no error is introduced by starting at a highertemp
38、erature. The bath should be well stirred.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 starting temperature shall be agreed upon b
39、etween 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 not be nearer than 3 mm to theedge of the specimen. Gently lower the needle rod, without theextra mass, so that the
40、 needle rests on the surface of thespecimen and holds it in position.10.3 Position the temperature measuring device so that thesensing end is located within 10 mm from where the load isapplied to the surface of the specimen. The sensing end shouldnot touch the specimen.10.4 Lower the assembly into t
41、he bath, taking care not to jarit in any way that would damage or dislodge the specimen.10.5 Apply the extra mass required to increase the load onthe specimen 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 tempera
42、ture 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 Aheating requirement shall be considered to be met if over every12-min interval during the test, the temperature of the bathrises 10 6 1C at each sp
43、ecimen location. The Rate B heatingrequirement shall be considered to be met if over every 6-mininterval during the test, the temperature of the bath rises12 6 1C at each specimen location. The selection of the rateof rise shall be agreed upon between cooperating laboratories.SeeAnnexA1 for calibrat
44、ion of single temperature probe units.10.7 Record the temperature of the bath when the needle haspenetrated 1 6 0.01 mm into the test specimen. Take care toensure that an accurate reading of the temperature is madesince the rate of penetration of the specimen will be increasingrapidly at this point.
45、10.8 Express the Vicat softening temperature as the arith-metic mean of the temperature of penetration 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.NO
46、TE 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
47、 penetration by means of a multichannelrecorder or similar data-acquisition device.NOTE 7Some commercially available instruments record the time atwhich the penetration reaches a set depth. If this type of instrument isused, make a time-temperature calibration before the specimens are tested.This ca
48、libration compensates for slight variations in the heating rate.(WarningEven though the variations may be within the specificationsD 1525 073set forth in 10.6, the compounded error over the range of the test canproduce a substantial error in the Vicat softening temperature.)11. Report11.1 Report the
49、 following information:11.1.1 Reference to this test method,11.1.2 Complete identification of the material tested,11.1.3 Method of preparing test specimens, including con-ditioning and annealing methods used,11.1.4 Initial starting temperature,11.1.5 Rate of temperature rise, Rate A (50C/h) or Rate B(120C/h),11.1.6 Total load applied to the specimen, Loading 1(10 6 0.2 N) or Loading 2 (50 6 1.0 N),11.1.7 Thickness of the specimen and the number of layersof the material that were used,11.1.8 Heat-transfer medium,11.1.9 Vicat softening tempe
