1、Designation: D685 17Standard Practice forConditioning Paper and Paper Products for Testing1This standard is issued under the fixed designation D685; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numbe
2、r in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice defines the standard atmospheres fornormal preconditioning, conditioning, and testing of paper andpaper products, paperboard,
3、 fiberboard, and containers madefrom them. It also specifies procedures for handling thesematerials in order that they may reach equilibrium with therespective atmosphere.1.2 This practice does not include special conditioning andtesting atmospheres, such as those that attempt to simulatetropical or
4、 arctic environments.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 t
5、o use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarri
6、ers to Trade (TBT) Committee.2. Referenced Documents2.1 ISO Standards:2ISO 187 Paper, Board and PulpsStandard Atmosphere forConditioning and Testing and Procedure for Monitoringthe Atmosphere and Conditioning of Samples2.2 TAPPI Standard:3TAPPI T400 Sampling and Acceptance of a Single Lot ofPaper, P
7、aperboard, Containerboard or Related ProductTAPPI/ANSI T402 Standard Conditioning and Testing At-mosphere for Paper, Board, Pulp Handsheets and RelatedProducts3. Significance and Use3.1 The preconditioning requirement is important becausephysical properties of a sample at 50 % relative humiditydepen
8、d upon whether the sample is brought to 50 % from ahigher or lower relative humidity. A detailed discussion of theimportance of preconditioning may be found in Annex A1.3.2 The conditioning and testing atmospheres are importantbecause both temperature and relative humidity have signifi-cant effects
9、on the physical properties of paper and board. Amore detailed discussion of the importance may be found inAnnex A2.3.3 This standard is technically identical to TAPPI T-402.4. Standard Atmospheres4.1 Preconditioning Atmosphere10 to 35 % relative hu-midity and 22 to 40C (see Annex A1 and Annex A2).4.
10、2 Conditioning Atmosphere50.0 6 2.0 % relative hu-midity and 23.0 6 1.0C.4.3 Testing AtmosphereSame as 4.2.NOTE 1Average values must fall within these limits. Momentaryfluctuations and measurement limitations may cause individual measure-ments to vary up to +2C (+3.6F) and +5 % relative humidity wit
11、houtsignificant impairment of test precision.5. Apparatus5.1 Preconditioning ChamberA room or cabinet in whichsample sheets or specimens may be individually exposed tocirculating air at the preconditioning relative humidity andtemperature.NOTE 2For smaller sheets or specimens, the required precondit
12、ioningmay be achieved easily with a simple cabinet, if no other means areavailable. If this cabinet is operated in a room maintained at 50 % relativehumidity and 23C and so designed that room air is drawn through it, andif the air entering and in the cabinet is heated to a temperature of 39 61C, the
13、 relative humidity in the cabinet will be in the required range (thatis, 20 6 3 % relative humidity). Commercially available forced-ventilation “ovens” should prove satisfactory. Input air to the oven shouldbe drawn from the standard room, output should be vented outside of thestandard room.5.1.1 Fo
14、r many papers and boards, approximately the samepreconditioning moisture content obtained by the above pro-cedure may be achieved by using a sealed cabinet operated in1This practice is under the jurisdiction of ASTM Committee D10 on Packagingand is the direct responsibility of Subcommittee D10.21 on
15、 Shipping Containers andSystems - Application of Performance Test Methods.Current edition approved April 1, 2017. Published June 2017. Originallyapproved in 1942. Last previous edition approved in 2012 as D685 12. DOI:10.1520/D0685-17.2Available from American National Standards Institute (ANSI), 25
16、W43rd St,4th Floor, New York, New York 10036, http:/www.ansi.org.3Available from Technical Association of the Pulp and Paper Industry (TAPPI)15 Technology Parkway South, Norcross GA 30092, http:/www.tappi.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM Internation
17、al, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. 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
18、 and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1a room maintained at 23 6 1C and using a saturated solutionof lithium chloride (LiCl) to obtain a relative humidity of about12 to 13 %.5.1.2 For larger rooms needed for preconditioning sealedcont
19、ainers and large sheets, the required low relative humiditymay be achieved by drawing air over a refrigerator expansioncoil operating at a few degrees above freezing temperature.5.2 Conditioning and Testing ChamberOne or morerooms or cabinets in which sample sheets or specimens may beindividually ex
20、posed to circulating air at the conditioningrelative humidity and temperature, and then tested under thesame conditions.NOTE 3The required relative humidity (50.0 6 2.0 %) and tempera-ture (23.0 6 1.0C) are difficult to achieve and therefore careful attentionmust be given to the design, evaluation,
21、and maintenance of the “standardroom.”5.3 HygrometerAny instrument that can indicate directlyor indirectly the relative humidity of the air with a calibratedaccuracy of 60.5 % relative humidity.5.4 ThermometerEither the dry bulb of a psychrometer(that is, a hygrometer of the wet- and dry-bulb type)
22、or aseparate thermometer of any convenient design. If a separatethermometer, it should be graduated to 0.2C or closer withscale errors not exceeding these values. (Psychrometer ther-mometers must be graduated and correct to 0.1C or closer andcarefully matched to each other to give the required accur
23、acyand repeatability in the measurement of relative humidity.)6. Procedure6.1 Obtain and preserve the sample in accordance withTAPPI T400. In particular, avoid exposure of the sample todirect sunlight, to extremes of temperature, and, to relativehumidities above 58 % (see Annex A1). If the sample is
24、 to beheld for some time before testing, preserve it at a temperaturebelow 25C and relative humidity below 58 %, but not below10 % as the paper may curl or cockle and change in otherrespects.NOTE 4It has been reported that low-temperature storage below 10Cslows aging effects. Samples should be prote
25、cted against condensation.6.2 Cut the specimens from a sample where critical dimen-sions are involved only after conditioning the sample. Wherethere are no critical dimensions, the specimens may be cutbefore preconditioning or conditioning.6.3 If shipping containers are to be sealed with aqueousadhe
26、sives, make the seal prior to preconditioning.6.4 Expose the sample sheets or specimens to the precon-ditioning atmosphere so that both surfaces of single sheets andexterior surfaces of laminated products or sealed containers arefreely exposed. This is best achieved by suspending them fromoverhead o
27、r supporting them on a wire grid or rack.6.5 Precondition the sample sheets or specimens by expos-ing them as specified in 6.4 to the preconditioning atmosphere.Precondition for a minimum of 24 h, unless a lesser time hasbeen found to give satisfactory results.NOTE 5For preconditioning apparatus of
28、ample capacity and aircirculation, the following preconditioning times have usually been foundsatisfactory: single sheets of paper, less than 1 h; liners corrugatingmedium, chip board, box board, 1 to 2 h; corrugated and solid fiber boardin sheet form, 5 to 10 h; sealed boxes and shipping containers
29、, 12 to 16 h;specially treated water vapor resistant papers and boards, 24 h and more.NOTE 6If the sample is to be stored for some time afterpreconditioning, store at a temperature below 25C and a relativehumidity below 40 % but not below 10 %.6.6 Condition the sample sheets or specimens by exposing
30、them as specified in 6.4 to the standard conditioning atmo-sphere for a sufficient time for them to come into equilibriumwith the atmosphere. Determine that equilibrium has beenobtained by weighing the sheets or specimens at time intervalswhich increase roughly geometrically. Plot the weight against
31、log time (that is, on semilogarithmic paper); the desiredequilibrium exists when the plotted curve becomes essentiallyparallel to the time axis.NOTE 7With good air circulation and ample capacity, a conditioningperiod of4hisusually sufficient for paper of ordinary weight andcomposition. A minimum tim
32、e of exposure of 5 to 8 h will be required forboards, and unsealed boxes, with a minimum time of 16 h or more forsealed fiberboard boxes, and much longer periods for boards of heavysubstances and specially treated water-vapor resistant papers (for example,a minimum of 72 h for wax treated containers
33、).6.7 Handle the preconditioned and conditioned sheets orspecimens as little as possible; especially avoid touching orbreathing on test areas.6.8 Test the specimens in the standard testing atmosphere.7. Report7.1 The report shall include the following:7.1.1 Temperature, relative humidity, and total
34、time of:7.1.1.1 Preconditioning,7.1.1.2 Conditioning before testing,7.1.2 Minimum and maximum temperature and relativehumidity during testing, and7.1.3 Any variations in procedure from this practice.8. Precision and Bias8.1 No statement is made about either the precision or thebias of the practice s
35、ince it merely states the environmentalconditions under which paper tests are to be carried out. Theycould affect the precision and bias of the test methods, but sucheffects are reflected in the precision and bias statement appear-ing in the individual test method.9. Keywords9.1 conditioning; paper;
36、 paper products; reconditioning;standard atmosphereD685 172ANNEXES(Mandatory Information)A1. IMPORTANCE OF PRECONDITIONINGA1.1 The physical properties of a sample at 50 % relativehumidity depend on whether the sample was brought to 50 %from higher or lower relative humidities. This “humidityhysteres
37、is effect” is 5 to 25 % of the test value for manyphysical properties. For example, a hysteresis effect of 1.5 %moisture content (or 25 % of the test value of 6 % moisturecontent) is typical. Preconditioning on the dry side within therange specified will avoid most of the hysteresis effect andresult
38、 in the moisture content of a given sample beingestablished within 0.15 % when the sample is later conditionedto 50 % relative humidity and 23 C. Conditioning down to50 % gives most papers a moisture content very nearly thesame as conditioning up to 60 %.A1.2 For the sake of obtaining close interlab
39、oratoryagreement, especially on physical properties, a specified pre-conditioning procedure is necessary but not always sufficient.While preconditioning practically eliminates the hysteresiseffect, it has little influence on strain relaxation effects. Thelatter depend on the entire previous moisture
40、 history of thesample, especially on the conditions of initial drying andtension, and on the duration and degrees of subsequentexcursions to high humidities (that is, above about 58 %relative humidity). Consequently, for very close interlaboratoryagreement a standardized procedure for handling the s
41、amplefrom manufacture to testing is required.A1.3 For mill control and similar intra-laboratory purposes,the preconditioning step may often be eliminated. For someproperties and materials, preconditioning may not benecessary, either because of the smallness of the humidityhysteresis effect or becaus
42、e of lower test accuracyrequirements.A2. IMPORTANCE OF TEMPERATUREA2.1 A tolerance of 1.0C has been adopted in a number ofcountries. It is recommended along with 62 % relative humid-ity by the technical committee, ISO/TC 125 on Enclosures andConditions for Testing, whenever close tolerances are requ
43、ired,as in paper and board testing. Both temperature and relativehumidity have significant effects on the physical properties ofpaper and board. For some properties of paper and board (forexample, MD tensile and CD stretch) a change of 1C mayhave nearly as much effect as a change of 2 % relativehumi
44、dity. For synthetic fibers and plastic laminates the tem-perature effect may be greater than the relative humidity effect.SUMMARY OF CHANGESCommittee D10 has identified the location of selected changes to this standard since the last issue (D685 12)that may impact the use of this standard. (Approved
45、 April 1, 2017.)(1) Removed previous Subsection 2.1 and renumbered subse-quent subsections accordingly.(2) Revised Subsections 2.1 and 2.2.(3) Added new Subsection 3.3.(4) Revised Note 1.(5) Revised 6.1.D685 173ASTM International takes no position respecting the validity of any patent rights asserte
46、d in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by th
47、e responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive
48、careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM Internat
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