1、Designation: D1525 171Standard 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 U.S. Department of Defense.1NOTEEditorial changes were made throughout the standard in September
3、2017.1. Scope*1.1 This test method covers determination of the tempera-ture at which a specified needle penetration occurs whenspecimens are subjected to specified controlled test conditions.1.2 This test method is not recommended for ethylcellulose, nonrigid poly(vinyl chloride), poly(vinylidenechl
4、oride), or other materials having a wide Vicat softeningrange.1.3 The values stated in SI units are to be regarded asstandard. No other units are included in this standard.1.4 Due to the potential safety and environmental hazardsassociated with mercury-filled thermometers, the use of alter-native te
5、mperature measuring devices (such as thermocouplesand RTDs) is encouraged with liquid-in-glass thermometerscontaining mercury, the use of alternative measuring devices,such as digital thermometers using thermocouple of RTDsensors is encouraged.1.5 This standard does not purport to address all of the
6、safety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health and environmental practices and deter-mine the applicability of regulatory limitations prior to use.NOTE 1This test method is equivalent to ISO 306 in all s
7、ections withthe exceptions of the allowance for creep, prior to the beginning of the testand the allowance of the fluidized powder as a heat transfer medium.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the
8、Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating
9、to PlasticsD1898 Practice for Sampling of Plastics (Withdrawn 1998)3E1 Specification for ASTM Liquid-in-Glass ThermometersE77 Test Method for Inspection and Verification of Ther-mometersE608/E608M Specification for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 Conductin
10、g an Interlaboratory Study toDetermine the Precision of a Test MethodE879 Specification for Thermistor Sensors for General Pur-pose and Laboratory Temperature MeasurementsE1137/E1137M Specification for Industrial Platinum Resis-tance ThermometersE2251 Specification for Liquid-in-Glass ASTM Thermom-e
11、ters with Low-Hazard Precision LiquidsE2935 Practice for Conducting Equivalence Testing inLaboratory Applications2.2 ISO Standards:4ISO 306 PlasticsThermoplastic MaterialDeterminationof Vicat Softening Temperature3. Terminology3.1 Definitions:3.1.1 Definitions of plastics used in this test method ar
12、e inaccordance with those defined in Terminology D883, unlessotherwise specified.3.1.2 Vicat softening temperaturethe temperature at whicha flat-ended needle of 1-mm2circular cross section willpenetrate a thermoplastic specimen to a depth of 1 mm under1This test method is under the jurisdiction ofAS
13、TM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.30 on Thermal Properties(Section D20.30.07).Current edition approved Aug. 1, 2017. Published August 2017. Originallyapproved in 1958. Last previous edition approved in 2009 as D1525 - 09. DOI:10.1520/D1525-17E01.2For re
14、ferenced 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.3The last approved version of this historical standard is referenced
15、 onwww.astm.org.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 1942
16、8-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Techni
17、cal Barriers to Trade (TBT) Committee.1a specified load (force) perpendicular to the test specimenusing a selected uniform rate of temperature rise.4. Summary 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 on
18、e of two accepted loads, as follows:Loading1 2 1060.2NLoading2 2 5061.0NThe specimen and needle are heated at either of two permis-sible rates, as follows:RateA 2 5065C/hRateB 2 120610C/hThe temperature at which the needle has penetrated to adepth of 1 6 0.01 mm is recorded as the Vicat softeningtem
19、perature.5. Significance and Use5.1 Data obtained by this test method is used to compare theheat-softening qualities of thermoplastic materials.5.2 This test method is useful in the areas of quality control,development, and characterization of plastic materials.6. Apparatus6.1 The instrument shall h
20、ave 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 inFig. 2 and shall consist of the following:6.1.1 Immersion BathAn immersion bath containing theheat-transfer medium shall be equipped with an
21、agitationsystem, temperature-measuring device, and heater. The heatershall have automatic control of the selected bath temperature-rise rate (see 4.1). The bath shall be constructed to allow thespecimens to be submerged at least 35 mm below the surfaceof the heat-transfer medium.FIG. 1 Apparatus for
22、 Softening Temperature Determination (Immersion Bath)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 Tem
23、perature-measuring device7 Test specimen8 Contact plateFIG. 2 Apparatus for Softening Temperature Determination (Di-rect Contact)D1525 17126.1.1.1 Heat-Transfer MediumShall be a liquid or fluid-ized powder.5Several liquids, such as silicone oils, glycerine,ethylene glycol, and mineral oil have been
24、used successfullyfor various plastics.6The medium used shall be free fromcontaminants and shall have no short-time effect at elevatedtemperatures on the material being tested, liquid mediums shallbe of low viscosity at room temperature.NOTE 2The results of the test can depend on the thermal diffusiv
25、ity ofthe heat-transfer medium.6.1.2 Contact Heating UnitShall consist of heater andheater blocks which, through conductive heating, raises thetemperature of the specimen at the required controlled rateuntil the VICAT Softening Temperature is reached.NOTE 3It is desirable to have a method of cooling
26、 or heating the bathin order to reduce the time required to change the temperature of the bathbetween tests more quickly. This may be accomplished by using a coolingcoil installed in the bath or an external heat-transfer system. If thetemperature rise rate is adversely affected by the presence of re
27、sidualcoolant in the cooling coils, the coolant should be purged prior tobeginning the test.6.1.3 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
28、shall be 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
29、 by a piece 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
30、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 of theweight of the needle r
31、od 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, mw5 F 2 Fs!/9.80665 2 mrwhere:F = total force to be applied to the specimen, N,Fs= force exerted by any
32、 penetration-measuring device, N(this is a positive value if the thrust of the spring istowards the specimen (downward), a negative value ifthe thrust of the spring is opposing the descent of therod, or zero if no such device is involved),mr= mass of the needle rod assembly, kg, andmw= extra mass ap
33、plied to attain the desired force, kg.Verification of the load shall be made on new equipment andafter replacing penetration-measuring devices, or at any time toensure that the equipment is in calibration. The calibrationprocedure for dial-gauge-type penetration-measuring devices isdescribed in Appe
34、ndix X1 and Appendix X2. The methods fordetermination of the thrust contributed by dial-gauge-typepenetration-measuring devices are also given in Appendix X1and Appendix X2.6.1.6 Temperature-Measuring Device, consisting of a sensor(for example, thermocouple, resistance thermometer (RTD),thermistor p
35、robe (E879), or platinum resistance thermometer(PRT).6.1.6.1 Digital ThermometerA digital indicating deviceincorporating a sensor (that is, thermocouple probe, thermistorprobe, or platinum resistance thermometer (PRT) with asso-ciated conditioning, conversion, and readout instrumentationadequate to
36、cover the range being tested. The sensor andrelated electronics shall be accurate to at least 60.5C.Thermocouples shall comply with the requirements of Speci-fication E608/E608M. Resistance thermometers shall complywith the requirements of Specification E1137/E1137M.6.1.6.2 Liquid-in-Glass Thermomet
37、erOlder systems stillin existence use a thermometer for temperature measurement ateach individual test station. The thermometer shall be one ofthe following, or its equivalent, as prescribed in SpecificationE1: Thermometer 1C or 2C, having ranges from 20 to 150Cor 5 to 300C, respectively, whichever
38、temperature range ismost suitable. Liquid-in-glass thermometers (refer to Specifi-cation E2251) shall be calibrated for the depth of immersion inaccordance with Test Method E77.NOTE 4WARNINGMercury has been designated by EPAand manystate agencies as a hazardous material that can cause central nervou
39、ssystem, kidney and liver damage. Mercury, or its vapor, may be hazardousto health and corrosive to materials. Caution should be taken whenhandling mercury and mercury containing products. See the applicableproduct Material Safety Data Sheet (MSDS) for details and EPAswebsite- http:/www.epa.gov/merc
40、ury/faq.htm - for additional informa-tion. Users should be aware that selling mercury and/or mercury contain-ing products into your state may be prohibited by state law.6.1.7 NeedleA flat-tipped, hardened steel needle with across-sectional area of 1.000 6 0.015 mm2(diameter of 1.120to 1.137 mm) shal
41、l 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 agreed upon between the seller and thepurchaser, sample in accordance with the sections on GeneralSampling Procedures a
42、nd 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 at least two specimens to test each sample. Thespecimen shall be flat, between 3 and 6.5 mm thick, and at least10 by 1
43、0 mm in area or 10 mm in diameter. If an individual5Aluminum 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.7Borosilicate glass or
44、Quartz has been found satisfactory for this purpose.D1525 1713layer of the specimen is less than 3 mm it is permissible tostack not more than three (3) layers to achieve the minimumthickness. The specimens shall be cut from sheet or moldedmaterial. The type of mold and the molding process used topro
45、duce test specimens will affect the results obtained in thetest. Molding conditions shall be in accordance with thestandard for the material being tested or be agreed uponbetween the cooperating laboratories.NOTE 5Discrepancies in test results due to variations in moldingconditions often are minimiz
46、ed by annealing the test specimens before thetest. Since different materials require different annealing conditions,annealing procedures shall be employed only if required by the materialstandard or if agreed upon between the cooperating laboratories.9. Conditioning9.1 If conditioning of the specime
47、ns 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 withProcedure A of Practice D618, unless otherwise specified byagreement or the relevant ASTM material specification. Incases of disagreement, the tolerances shall
48、 be 61C and 65%relative humidity.NOTE 6Conditioning periods less 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 longe
49、r toreach temperature and humidity equilibrium. Refer to the applicableASTM 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 bystarting at a higher temperature. The immersion bath systemshall be well agitated.10.1.1 If it is not possible to reduce the temperature of theheat-transfer medium to 20-23C, it is permi
