1、Designation: D618 13Standard Practice forConditioning Plastics for Testing1This standard is issued under the fixed designation D618; 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 parentheses
2、 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. Scope*1.1 In general, the physical and electrical properties ofplastics are influenc
3、ed by temperature and relative humidity ina manner that materially affects test results. In order to makereliable comparisons between different materials and betweendifferent laboratories, it is necessary to standardize the humid-ity conditions, as well as the temperature, to which specimensof these
4、 materials are subjected prior to and during testing. Thispractice defines procedures for conditioning plastics (althoughnot necessarily to equilibrium) prior to testing, and the condi-tions under which they shall be tested.1.2 For some materials, it is possible that a material speci-fication exists
5、 that requires the use of this practice, but withsome procedural modifications. The material specificationtakes precedence over this practice. Refer to the materialspecification before using this practice. Table 1 in Classifica-tion D4000 lists the ASTM material specifications that cur-rently exist.
6、1.3 This standard does not purport to address all 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 stan
7、dard and ISO 291 address the same subject matter,but differ in technical content. ISO 291 describes only two temperatureand humidity conditions for conditioning or testing, or both.2. Referenced Documents2.1 ASTM Standards:2D709 Specification for Laminated Thermosetting MaterialsD756 Practice for De
8、termination of Weight and ShapeChanges of Plastics UnderAccelerated Service Conditions(Withdrawn 1998)3D4000 Classification System for Specifying Plastic Materi-alsD5032 Practice for Maintaining Constant Relative Humidityby Means of Aqueous Glycerin SolutionsE104 Practice for Maintaining Constant Re
9、lative Humidityby Means of Aqueous Solutions2.2 ISO Standard:ISO 291 PlasticsStandard Atmospheres for Conditioningand Testing43. Terminology3.1 Definitions:3.1.1 room temperaturea temperature in the range from 20to 30C (68 to 86F).3.1.2 standard laboratory atmospherean atmosphere hav-ing a temperatu
10、re of 23C (73.4F) and a relative humidity of50 % with standard tolerances as specified in Section 8 shall bethe standard laboratory atmosphere.3.1.3 standard laboratory temperaturea temperature of23C (73.4F) with standard tolerance as specified in Section 7shall be the standard laboratory temperatur
11、e.4. Significance and Use4.1 Conditioning of specimens is typically conducted: (1)for the purpose of bringing the material into equilibrium withnormal or average room conditions, (2) simply to obtainreproducible results, regardless of previous history ofexposure, or (3) to subject the material to ab
12、normal conditionsof temperature or humidity in order to predict its servicebehavior.4.2 The conditioning procedures prescribed in this practiceare designed to obtain reproducible results and have thepotential to give physical values somewhat higher or somewhatlower than values under equilibrium at n
13、ormal conditions,1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.50 on Durability of Plastics.Current edition approved June 1, 2013. Published July 2013. Originally approvedin 1941. Last previous edition approved in 2008 a
14、s D618 - 08. DOI: 10.1520/D0618-13.2For 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.3The last approved version
15、 of this historical standard is referenced 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 Driv
16、e, PO Box C700, West Conshohocken, PA 19428-2959. United States1depending upon the particular material and test. Depending onthe thickness, type of material and its previous history, it ispossible that it would take 20 to 100 days or more to ensuresubstantial equilibrium under normal conditions of h
17、umidityand temperature. Consequently, conditioning for reproducibil-ity must of necessity be used for general purchase specifica-tions and product control tests.5. Sampling5.1 Sampling shall be in accordance with the ASTM testmethods for the specific properties to be determined.6. Test Specimens6.1
18、The numbers and types of test specimens shall be inaccordance with the ASTM test methods for the specificproperties to be determined.7. Requirements for Conditioning Atmospheres7.1 When data are to be obtained for comparison purposesat a specific temperature, select the test temperature andassociate
19、d tolerance from Table 1.7.1.1 Unless otherwise specified, tolerance for temperatureshall be as given in Table 1.7.1.2 When a tolerance of 61C (61.8F) is required, itshall be specified and shall be reported.7.1.3 The position for measurement of temperature andrelative humidity measurementmeasurement
20、s shall be madeas close as possible to the center of the room or chamber.7.1.3.1 It is possible that the temperature and relativehumidity measured are not representative of a conditionelsewhere in an enclosure or room because of local effects ordeficiency in circulation of air. If required, addition
21、al measure-ments shall be made throughout the area to show compliance tothe temperature and relative humidity conditions specified.7.2 Relative Humidity:7.2.1 When tolerance for temperature is 62C, the tolerancefor relative humidity shall be 610 %.7.2.2 When tolerance for temperature is 61C, the tol
22、erancefor relative humidity shall be 65%.NOTE 2Annex B of ISO 291 provides background information on thecalculation of tolerance for relative humidity based on the allowedfluctuation in set point temperature.8. Designations for Conditioning8.1 Designation for Conditioning Prior to Test:8.1.1 Designa
23、te conditioning of test specimens as follows:8.1.1.1 A number indicating in hours the duration of theconditioning,8.1.1.2 A number indicating in degrees Celsius the condi-tioning temperature, or8.1.1.3 A number indicating relative humidity, wheneverrelative humidity is controlled, or a word to indic
24、ate immersionin a liquid.8.1.2 The numbers shall be separated from each other byslant marks. A sequence of conditions shall be denoted by useof a plus ( + ) sign between successive conditions. “Des” shallbe used to indicate desiccation over anhydrous calcium chlo-ride. Temperature and relative humid
25、ity tolerances shall be inaccordance with Section 7, unless otherwise specified.NOTE 3Examples:Condition 96/23/50Condition 96 h at 23C and 50 % relative humidity.Condition 48/50/waterCondition 48 h at 50C in water.Condition 48/50 + 96/23/50Condition 48 h at 50C; then condition 96 hat 23C and 50 % re
26、lative humidity.Condition 48/50 + DesCondition 48 h at 50C followed by desiccation.8.2 Designation for Test Condition:8.2.1 Designate test conditions as follows:8.2.1.1 A capital letter “T” following the prior conditioningdesignation and separated therefrom by a colon.8.2.1.2 A number indicating in
27、degrees Celsius the testtemperature;8.2.1.3 A number indicating the relative humidity in the testwhenever relative humidity is controlled.8.2.2 The numbers shall be separated from each other by aslant mark, and from the “T” by a dash. Temperature andrelative humidity tolerances shall be in accordanc
28、e withSection 7, unless otherwise specified.NOTE 4Examples:Condition 24/180: T180Condition 24 h at 180C: Test at 180C.Condition 96/35/90: T3590Condition 96 h at 35C and 90 %relative humidity: Test at 35C and 90 % relative humidity.9. Standard Procedures for Conditioning Prior to Test9.1 Procedure AC
29、ondition 40/23/50 for specimens 7 mm(0.25 in.) or under in thickness, 88/23/50 for specimens over 7mmCondition test specimens 7 mm or under in thickness inthe standard laboratory atmosphere for a minimum of 40 hTABLE 1 Test Temperatures and TolerancesTestTemperatures, C (F)ATolerance,plus or minus,
30、C (F)70 (94) 2.0 (3.6)55 (67) 2.0 (3.6)40 (40) 2.0 (3.6)25 (13) 2.0 (3.6)0 (32) 2.0 (3.6)23 (73)B2.0 (3.6)35 (95) 2.0 (3.6)50 (122) 2.0 (3.6)70 (158) 2.0 (3.6)90 (194) 2.0 (3.6)105 (221) 2.0 (3.6)120 (248) 2.0 (3.6)130 (266) 2.0 (3.6)155 (311) 2.0 (3.6)180 (356) 2.0 (3.6)200 (392) 3.0 (5.4)225 (437)
31、 3.0 (5.4)250 (482) 3.0 (5.4)275 (527) 3.0 (5.4)300 (572) 3.0 (5.4)325 (617) 4.0 (7.2)350 (662) 5.0 (9.0)400 (752) 6.0 (10.8)450 (842) 8.0 (14.4)500 (932) 10.0 (18.0)600 (1112) 12.0 (21.6)AThe test temperature is the temperature at which the chamber or room iscontrolled. The tolerance is the maximum
32、 allowable variation of the temperatureindicated by the temperature output device during equilibrium conditions. If theindicated temperature is outside the limit defined by the test temperature plus orminus the tolerance, immediately implement procedures to correct the problem.BStandard Laboratory T
33、emperature.D618 132immediately prior to testing. Treat test specimens over 7 mm inthickness as above, except that the minimum time shall be88 h. Provide adequate air circulation on all sides of the testspecimens by placing them in suitable racks, hanging themfrom metal clips or laying them on wide-m
34、esh, wire screenframes with at least 25 mm (1 in.) between the screen and thesurface of the bench.NOTE 5Procedure A is generally satisfactory and is recommendedunless other methods are specified. Note that Procedure A of PracticeD618 differs from Condition A of Specification D709 and of the Military
35、Specifications MIL-P designation in that Condition A means “as received,no special conditioning.”NOTE 6If for any particular material or test, a specific longer time ofconditioning is required, the time shall be agreed upon by the interestedparties. It is acceptable to use shorter conditioning times
36、 for thinspecimens provided equilibrium is substantially obtained.9.2 Procedure BCondition 48/50 + DesConditionspecimens for a period of 48 h in a circulating-air oven at atemperature of 50 6 2C (122 6 3.6F). Remove the speci-mens from the oven and cool to the room temperature in adesiccator over an
37、hydrous calcium chloride for a period of atleast 5 h for specimens 7 mm (0.25 in.) or under in thickness,and at least 15 h for specimens over 7 mm in thickness,immediately prior to testing.NOTE 7Procedure B is commonly used for the purpose of obtainingreproducible test results on the thermosetting m
38、aterials by means of ashort-time conditioning period, or where the specific effects of moderatedrying are to be determined. The use of other enclosures, desiccants, ordesiccating techniques that produce and maintain an atmosphere equiva-lent to that over anhydrous calcium chloride is acceptable. Not
39、e thatProcedure B of Practice D618 is the same as Condition E-48/50 ofSpecifications D709 and of the Military Specifications MIL-P designation.9.3 Procedure CCondition 96/35/90Condition speci-mens for a period of 96 h in an atmosphere of 90 % relativehumidity at a temperature of 35C (95F). The toler
40、ances forthis procedure shall be as follows:Time, h 2Temperature, C (F) 1 (1.8)Humidity, % 2NOTE 8Procedure C is recommended wherever the specific effects ofexposure to severe atmospheric moisture are to be determined.NOTE 9It has been found that, for certain tests and materials, morereliable data a
41、re obtained in enclosures with circulating air rather than stillair. In such cases use enclosures with circulating air.9.4 Procedure DCondition 24/23/waterConditionspecimens by immersion in distilled water for 24 612 hat236 1C (73.4 6 1.8F).9.5 Procedure ECondition 48/50/water + 1/23/waterCondition
42、specimens by immersion in distilled water for 48 612 hat506 1C (122 6 1.8F), and cool them by immersionin a sufficient quantity of distilled water to reduce the tempera-ture to 23C (73.4F) within 1 h.NOTE 10Procedures D and E have been found useful in ASTMelectrical and mechanical tests, and are use
43、d extensively in MilitarySpecifications MIL-P designation.9.6 Procedure FCondition /23/96 (time as specified inapplicable materials specification)Condition specimens in anatmosphere of 96 6 1 % relative humidity at a temperature of23 6 1C (73.4 6 1.8F) for a period of time as specified in theapplica
44、ble materials specification.9.7 Procedure GCondition 40/27/65 for specimens 7 mm(0.25 in.) or under in thickness, 88/27/65 for specimens over 7mmCondition test specimens in the standard laboratoryatmosphere for the minimum of 40 or 88 hours prior to testing.NOTE 11Procedure G has been found useful i
45、n tropical climates.9.8 Constant relative humidity can be obtained only bycareful temperature control. Procedures for maintaining closetolerances are described in Practice E104. When use of acid orsalt solutions has a deleterious effect on materials being tested,use glycerin solutions in accordance
46、with Practice D5032 tocontrol relative humidity.NOTE 12A considerable number of other procedures that might beconsidered as functional are outlined in Practice D756.NOTE 13It has been found that, for certain tests and materials, morereliable data are obtained in enclosures with circulating air rathe
47、r than stillair. In such cases enclosures with circulating air should be used.10. Tests at Normal Temperatures10.1 Unless otherwise specified, test materials conditionedin the standard laboratory atmosphere in the same atmosphere.10.2 Unless otherwise specified, test materials conditionedin accordan
48、ce with Procedure B at room temperature condi-tions. Start the test as soon as possible, but do not allow morethan12 h to elapse between removal of the specimens from thedesiccator and the start of the tests.10.3 Unless otherwise specified, test materials conditionedin accordance with Procedures C a
49、nd F in the same atmo-sphere.10.4 Unless otherwise specified, wipe materials conditionedin accordance with Procedures D and E immediately with adamp cloth, then with a dry cloth, and test them at roomtemperature. Specimens should only be removed from thewater as the tests are ready to be conducted. Start the testsimmediately and complete them as soon as possible.11. Tests at Other Standard Test Temperatures11.1 When tests are desired at standard test temperaturesprescribed in Section 7, transf
