1、Designation: D 618 05Standard Practice forConditioning Plastics for Testing1This standard is issued under the fixed designation D 618; 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 parenthes
2、es 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 In general, the physical and electrical properties ofplastics are influ
3、enced by temperature and relative humidity ina manner that materially affects test results. In order thatreliable comparisons may be made of different materials andbetween different laboratories, it is necessary to standardize thehumidity conditions, as well as the temperature, to whichspecimens of
4、these materials are subjected prior to and duringtesting. This practice defines procedures for conditioningplastics (although not necessarily to equilibrium) prior totesting, and the conditions under which they shall be tested.1.2 For some materials, there may be a material specifica-tion that requi
5、res the use of this practice, but with someprocedural modifications. The material specification takesprecedence over this practice. Refer to the material specifica-tion before using this practice. Table 1 in Classification D 4000lists the ASTM material specifications that currently exist.1.3 This st
6、andard 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 1ISO 291 is related t
7、o this practice; however, ISO 291 de-scribes only two temperature and humidity conditions for conditioning ortesting, or both.2. Referenced Documents2.1 ASTM Standards:2D 709 Specification for Laminated Thermosetting MaterialsD 756 Practice for Determination of Weight and ShapeChanges of Plastics Un
8、der Accelerated Service ConditionsD 4000 Classification System for Specifying Plastic Mate-rialsD 5032 Practice for Maintaining Constant Relative Humid-ity by Means of Aqueous Glycerin SolutionsE 104 Practice for Maintaining Constant Relative Humidityby Means of Aqueous Solutions2.2 ISO Standard:ISO
9、 291 PlasticsStandard Atmospheres for Conditioningand Testing33. Terminology3.1 Definitions:3.1.1 room temperaturea temperature in the range from20 to 30C 68 to 85F.3.1.2 standard laboratory atmospherean atmosphere hav-ing a temperature of 23C 73.4F and a relative humidity of50 % with standard toler
10、ances as specified in 3.2 shall be thestandard laboratory atmosphere.3.1.3 standard laboratory temperaturea temperature of23C 73.4F with standard tolerance as specified in 3.2 shallbe the standard laboratory temperature.3.2 Tolerances:3.3 relative humiditystandard tolerance shall be 65%.3.3.1 Discus
11、sionWhere the closer tolerance 62 % is re-quired, it may be specified and the tolerance used reported.3.4 standard test temperatures other than standard labora-tory temperaturewhen data are to be obtained for compari-son purposes at a specific temperature either above or belowthe standard laboratory
12、 temperature, the temperature should beselected from the following:TestTemperatures, C FTolerance,plus or minus, C F70 94 2.0 3.655 67 2.0 3.640 40 2.0 3.625 13 2.0 3.60 32 2.0 3.635 95 1.0 1.850 122 2.0 3.670 158 2.0 3.690 194 2.0 3.6105 221 2.0 3.6120 248 2.0 3.6130 266 2.0 3.6155 311 2.0 3.6180 3
13、56 2.0 3.6200 392 3.0 5.4225 437 3.0 5.41This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.50 on Permanence Properties.Current edition approved November 1, 2005. Published November 2005.Originally approved in 1941. Last previ
14、ous edition approved in 2000 as D 618 - 00.2For 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.3Available from Am
15、erican National Standards Institute (ANSI), 25 W. 43rd 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.TestTemperatures, C FTolerance
16、,plus or minus, C F250 482 3.0 5.4275 527 3.0 5.4300 572 3.0 5.4325 617 4.0 7.2350 662 5.0 9.0400 752 6.0 10.8450 842 8.0 14.4500 932 10.0 18.0600 1112 12.0 21.63.5 temperaturestandard tolerance shall be 62C63.6F.3.5.1 DiscussionWhere the closer tolerance 61C61.8F is required, it may be specified an
17、d the tolerance usedreported.3.6 temperature and relative humidity measurementmeasurements shall be made as close as possible to the centerof the room or chamber.3.6.1 DiscussionThe temperature and relative humidityindicated at the control point, or on a recorder, may not berepresentative of a condi
18、tion elsewhere in an enclosure or roombecause of local effects or deficiency in circulation of air.Additional measurements shall be made throughout the area toshow compliance to the temperature and relative humidityrequired.4. Significance and Use4.1 Conditioning of specimens may be undertaken: (1)
19、forthe purpose of bringing the material into equilibrium withnormal or average room conditions, (2) simply to obtainreproducible results, regardless of previous history of expo-sure, or (3) to subject the material to abnormal conditions oftemperature or humidity in order to predict its service behav
20、ior.4.2 The conditioning procedures prescribed in this practiceare designed to obtain reproducible results and may givephysical values somewhat higher or somewhat lower thanvalues under equilibrium at normal conditions, depending uponthe particular material and test. To ensure substantial equilib-ri
21、um under normal conditions of humidity and temperature,however, may require from 20 to 100 days or more dependingupon thickness and type of material and its previous history.Consequently, conditioning for reproducibility must of neces-sity be used for general purchase specifications and productcontr
22、ol tests.5. Sampling5.1 Sampling shall be in accordance with the ASTM testmethods for the specific properties to be determined.6. Test Specimens6.1 The numbers and types of test specimens shall be inaccordance with the ASTM test methods for the specificproperties to be determined.7. Designations for
23、 Conditioning7.1 Designation for Conditioning Prior to Test:7.1.1 Conditioning of test specimens may be designated asfollows:7.1.1.1 A number indicating in hours the duration of theconditioning,7.1.1.2 A number indicating in degrees Celsius the condi-tioning temperature, or7.1.1.3 A number indicatin
24、g relative humidity, wheneverrelative humidity is controlled, or a word to indicate immersionin a liquid.7.1.2 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 indic
25、ate desiccation over anhydrous calcium chlo-ride. Temperature and relative humidity tolerances shall be inaccordance with Section 3, unless otherwise specified.NOTE 2Examples:Condition 96/23/50Condition 96 h at 23C and 50 % relative humidity.Condition 48/50/waterCondition 48 h at 50C in water.Condit
26、ion 48/50 + 96/23/50Condition 48 h at 50C; then condition 96 hat 23C and 50 % relative humidity.Condition 48/50 + DesCondition 48 h at 50C followed by desiccation.7.2 Designation for Test Condition:7.2.1 Test condition may be designated as follows:7.2.1.1 A capital letter “T” following the prior con
27、ditioningdesignation and separated therefrom by a colon.7.2.1.2 A number indicating in degrees Celsius the testtemperature;7.2.1.3 A number indicating the relative humidity in the testwhenever relative humidity is controlled.7.2.2 The numbers shall be separated from each other by aslant mark, and fr
28、om the “T” by a dash. Temperature andrelative humidity tolerances shall be in accordance withSection 3, unless otherwise specified.NOTE 3Examples: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 %
29、relative humidity.8. Standard Procedures for Conditioning Prior to Test8.1 Procedure ACondition 40/23/50 for specimens 7 mm0.25 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 himme
30、diately 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-mesh, wire screenframes
31、with at least 25 mm 1 in. between the screen and thesurface of the bench.NOTE 4Procedure A is generally satisfactory and is recommendedunless other methods are specified. Note that Procedure A of PracticeD 618 differs from Condition A of Specification D 709 and of the MilitarySpecifications MIL-P de
32、signation in that Condition A means “as received,no special conditioning.”NOTE 5If for any particular material or test, a specific longer time ofconditioning is required, the time shall be agreed upon by the interestedparties. Shorter conditioning times may be used for thin specimensprovided equilib
33、rium is substantially obtained.8.2 Procedure BCondition 48/50 + DesCondition thespecimens 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 aD618052desiccator over anhydrous calcium chloride f
34、or 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 6Procedure B is commonly used for the purpose of obtainingreproducible test results on the thermosetting materials by means of ashort-
35、time conditioning period, or where the specific effects of moderatedrying are to be determined. Other enclosures, desiccants, or desiccatingtechniques may be used that produce and maintain an atmosphereequivalent to that over anhydrous calcium chloride. Note that Procedure Bof Practice D 618 is the
36、same as Condition E-48/50 of SpecificationsD 709 and of the Military Specifications MIL-P designation.8.3 Procedure CCondition 96/35/90Condition thespecimens for a period of 96 h in an atmosphere of 90 %relative humidity at a temperature of 35C 95F. The toler-ances for this procedure shall be as fol
37、lows:Time, h 62Temperature, C F 61 1.8Humidity, % 62NOTE 7Procedure C is recommended wherever the specific effects ofexposure to severe atmospheric moisture are to be determined.NOTE 8It has been found that, for certain tests and materials, morereliable data are obtained in enclosures with circulati
38、ng air rather than stillair. In such cases enclosures with circulating air should be used.8.4 Procedure DCondition 24/23/waterCondition thespecimens by immersion in distilled water for 24 612 hat236 1C 73.4 6 1.8F.8.5 Procedure ECondition 48/50/water + 1/23/waterCondition the specimens by immersion
39、in distilled water for 48612 hat506 1C 122 6 1.8F, and cool them byimmersion in a sufficient quantity of distilled water to reducethe temperature to 23C 73.4F within 1 h.NOTE 9Procedures D and E have been found useful in ASTMelectrical and mechanical tests, and are used extensively in MilitarySpecif
40、ications MIL-P designation.8.6 Procedure FCondition /23/96 (time as specified inapplicable materials specification)Condition the specimensin an atmosphere of 96 6 1 % relative humidity at a tempera-ture of 23 6 1C 73.4 6 1.8F for a period of time asspecified in the applicable materials specification
41、.NOTE 10Constant relative humidity can be obtained only by carefultemperature control. Procedures for maintaining close tolerances aredescribed in Practice E 104. When use of acid or salt solutions has adeleterious effect on materials being tested, use glycerin solutions inaccordance with Practice D
42、 5032 to control relative humidity.NOTE 11A considerable number of other procedures that might beconsidered as functional are outlined in Practice D 756.NOTE 12It has been found that, for certain tests and materials, morereliable data are obtained in enclosures with circulating air rather than still
43、air. In such cases enclosures with circulating air should be used.9. Tests at Normal Temperatures9.1 Unless otherwise specified, test materials conditioned inthe standard laboratory atmosphere in the same atmosphere.9.2 Unless otherwise specified, test materials conditioned inaccordance with Procedu
44、re B at room temperature conditions.Start the test as soon as possible, but do not allow more than12h to elapse between removal of the specimens from thedesiccator and the start of the tests.9.3 Unless otherwise specified, test materials conditioned inaccordance with Procedures C and F in the same a
45、tmosphere.9.4 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 testsimmed
46、iately and complete them as soon as possible.10. Tests at Other Standard Test Temperatures10.1 When tests are desired at standard test temperaturesprescribed in 3.4, transfer materials to the test conditionswithin12 h, preferably immediately, after completion of thepreconditioning (in accordance wit
47、h Procedure A or B). Holdthe specimens at the test temperature for no more than 5 h priorto test, and in no case for less than the time required to ensurethermal equilibrium.NOTE 13Specific materials, specimen geometries, or physical condi-tioning arrangements require more than5htoreach thermal equi
48、librium.In these cases, or for materials that are not adversely affected by longerconditioning times, it is permissible to use conditioning times longer than5h.11. Selection of Conditioning Procedure11.1 In the case of materials covered by ASTM specifica-tions, reference should be made thereto to de
49、termine theconditioning procedures to be used.11.2 In the case of all other materials, the choice betweenprocedures should preferably be based on the one that gives themost reproducible test results.12. Report12.1 The report of any test referencing this practice shallstate:12.1.1 Conditioning procedure used,12.1.2 Conditioning time used, to the nearest1
