1、Designation: D 4678 04Standard Practice forRubberPreparation, Testing, Acceptance, Documentation,and Use of Reference Materials1This standard is issued under the fixed designation D 4678; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers materials used on an industry-widebasis as reference materials, which are vital
3、ly important toconduct product, specification, and development testing in therubber and carbon black industry. This practice describes thesteps necessary to ensure that any candidate material, that hasa perceived need, can become a Reference Material. Thepractice sets forth the recommendations on th
4、e preparationsteps for these materials, on the testing that shall be conductedto permit acceptance of any candidate material, and on how thedocumentation needed for the acceptance shall be recorded forfuture use and review.1.2 This practice shall be administered by ASTM Commit-tee D11 in consultatio
5、n on all matters with Committee D24.1.2.1 Important sections of this practice are as follows:SectionSignificance and Use 3Preparation of Industry Reference Materials 4Overview of Industry Reference Material Testing 5Chemical and Physical Specifications for IRM 6Reference Material Documentation 7Assi
6、gnment and Tabulation of Reference Material Numbers 8Typical Reference Material Use 9Recommended Package Size for IRM Annex A1Recommended Sampling Plans for Homogeneity Testing of anIRMAnnex A2Test Plan and Analysis for Homogeneity of an IRM Annex A3Test Plan and Analysis to Evaluate an Accepted Ref
7、erence ValueAnnex A4Statistical Model(s) for IRM Testing Annex A5Example of Annex Calculations for a Typical IRM Appendix X1Two-Way Analysis of Variance for Calculating Sr Appendix X2Inventory of NIST Rubber Compounding SRMs Appendix X31.3 This standard does not purport to address all of thesafety c
8、oncerns, 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.2. Referenced Documents2.1 ASTM Standards:2D 4483 Practice for Evaluating Preci
9、sion for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesE 122 Practice for Calculating Sample Size to Estimate,With a Specified Tolerable Error, the Average for aCharacteristic of a Lot or ProcessE 691 Practice for Conducting an Interlaboratory Study toDetermine the Preci
10、sion of a Test MethodE 826 Practice for Testing Homogeneity of Materials forDevelopment of Reference Materials3. Significance and Use3.1 Reference materials are vitally important in product andspecification testing, in research and development work, intechnical service work, and in quality control o
11、perations in therubber and carbon black industries. They are especially valu-able for referee purposes.3.2 Categories, Classes, and Types of Reference Materials(RM):3.2.1 Reference materials are divided into two categories:3.2.1.1 Industry Reference Materials (IRM)Materials thathave been prepared ac
12、cording to a specified production processto generate a uniform lot; the parameters that define the qualityof the lot are evaluated by a specified measurement program.3.2.1.2 Common-Source Reference Materials (CRM)Materials that have been prepared to be as uniform as possiblebut do not have establish
13、ed property (parameter) values; theknowledge of a common or single source is sufficient forcertain less critical applications.3.2.2 Industry reference materials (IRMs) are divided intoadditional classes and types according to the method ofevaluating the lot parameters and according to the production
14、process for generating the lot material. These are explained1This practice is under the jurisdiction ofASTM Committee D11 on Rubber andis the direct responsibility of Subcommittee D11.20 on Compounding Materials andProcedures.Current edition approved Dec. 1, 2004. Published January 2005. Originallya
15、pproved in 1987. Last previous edition approved in 2001 as D 4678 94 (2001).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 onth
16、e ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.more fully (refer to Annex A3 and Annex A4 for more detailson the discussion in Section 3).3.2.3 The following lot parameters are important for refer-ence material use:3.
17、2.3.1 Accepted Reference Value (AR Value)An averageIRM property or parameter value established by way of aspecified test program.3.2.3.2 Test Lot Limits (TL Limits)These are limits de-fined as 63 times the standard deviation of individual IRM testresults across the entire lot for the property or par
18、ameter(s) thatdefines lot quality; the measurements are conducted in thelaboratory of the organization producing the IRM.3.2.3.3 Although the limits as defined in 3.2.3.2 are given interms of 63 times the standard deviation, the rejection ofindividual portions of the lot as being outlier or non-typi
19、calportions in assessing the homogeneity of the lot is done on thebasis of 62 times the appropriate standard deviation, that is, onthe basis of a 95 % confidence interval. See Annex A3 andAnnexA4 for more information and the evaluation procedures.3.2.4 All IRMs have an AR value and TL limits; howeve
20、rthe AR value may be obtained in one of two ways to produceone of two classes of AR values:3.2.4.1 Global AR ValueThis AR value is obtained froman interlaboratory test program where the word “global”indicates an average value across many laboratories.3.2.4.2 Local AR ValueThis is an AR value obtaine
21、d inone laboratory or at one location, usually the laboratoryresponsible for preparation of the homogeneous lot.3.2.5 An additional parameter is of importance for IRMsthat have a global AR value:3.2.5.1 Between-Laboratory Limits (BL)The group oflaboratories that conduct interlaboratory testing to es
22、tablish anAR-value are not equivalent to a system or population typicalof industrial production operations that use the usual 63standard deviation limits. Such production operations aresystems that have been purged of all assignable causes ofvariation and are in a state of statistical control with o
23、nlyrandom variations that cannot be removed. Thus, the recom-mended limits on all IRMs are the 62 standard deviation limitsthat pertain to a 95 % confidence level. If for serious reasonsthat can be totally justified, 63 standard deviation limits arerequired, these may be used provided that full and
24、completedocumentation is supplied to justify the limits.3.2.6 The homogeneity or uniformity of the lot, whichdetermines the magnitude of the TL limits, may be designatedas one of two different levels of uniformity. The key factor thatdetermines the level of uniformity is the capability of blendingth
25、e IRM portions or parts that constitute the lot, to ensure ahigh degree of uniformity from the blending process. IRMsthat cannot be blended will have an extra residual amount ofvariation (portion to portion) that lowers the level of unifor-mity.3.2.6.1 Uniformity Level 1 (UL-1)This is the most uni-f
26、orm or highest level of homogeneity that can be attained bythe use of a specified test for measuring the parameter thatdefines lot quality; it is obtained by the use of a blendedmaterial and is referred to as a Type B (B = blended) IRM.3.2.6.2 Uniformity Level 2 (UL-2)This is the lesser degreeof uni
27、formity that is attained by the use ofa specified test formeasuring the parameter that defines lot quality; it is normallyobtained for non-blended materials and is referred to as a TypeNB (not blended) IRM.3.3 IRMs have a number of use applications in the technicalareas, as cited in 3.1.3.3.1 Single
28、 Laboratory Self EvaluationThe IRM may beused in a given laboratory (or with a given test system) tocompare the test results within the laboratory to the acceptedreference value for the IRM. An IRM can also be used forinternal statistical quality control (SQC) operations.3.3.2 Multi-Laboratory Evalu
29、ationThe IRM may be usedbetween two or more laboratories to determine if the testsystems in the laboratories are operating within selectedcontrol limits.3.3.3 One or more IRMs may be used in the preparation ofcompounds to be used for evaluating non-reference materialsin compound testing and performa
30、nce.3.3.4 Reference liquid IRMs may be used for immersiontesting of various candidate or other reference compounds.Such immersion testing is important due to the deleteriousinfluences of immersion liquids on rubber compounds.3.3.5 IRMs may also be used to eliminate interlaboratorytesting variation k
31、nown as “test bias:” a difference between two(or more) laboratories that is essentially constant between thelaboratories for a given test property level, irrespective of thetime of the test comparisons. In such applications a differentialtest measurement value, (IRM experimental material), be-comes
32、a corrected test result; this corrected value is used as themeasure of performance rather than the “as-measured” testvalue on the experimental material of interest.3.4 Average values play an important role in various opera-tions and decisions in this practice. For this practice, “average”is defined
33、as the arithmetic mean.3.5 The various characteristics of IRMs and CRMs (catego-ries, classes, types) are listed in summary form in Table 1.3.6 This practice and the IRM program it describes is beingdeveloped to replace a standardization program conducted bythe National Institute of Standards and Te
34、chnology (NIST) thatwas begun in 1948 and is being phased out. The standardmaterials developed by the NIST program are referred to asStandard Reference Materials or SRM.3.7 To provide for some continuity in the “phase-outphase-in” operation, Appendix X3 lists the rubber and com-pounding materials st
35、ill carried by NIST on an interim basis.TABLE 1 Categories of Reference MaterialsAIRM CRMAR Value Global Local NoneHomogeneity Type B Type NB Type B Type NB Single Source(TL Limits) (UL-1) (UL-2) (UL-1) (UL-2) Materialor (UL-1) or (UL-1)AAR value = accepted reference value.TL limits = test lot limit
36、s.Global = AR value obtained from an interlaboratory test program.Local = AR value obtained from one laboratory.Type-B = IRM that has been blended to ensure high uniformity.Type-NB = IRM that cannot be blended.UL-1 and UL-2 = levels of uniformity in the IRM lot; UL-1 is higher uniformitythan UL-2.Se
37、e Annex A3 and Annex A4 for more information.D4678042Appendix X3 will be retained in this practice until such time asNIST materials are no longer used.3.8 It is not feasible to write into this practice all thenecessary specifications, modes of preparation, sampling, andtesting protocols, for the wid
38、e variety of materials that willeventually become IRM. Therefore this practice is published togive general guidelines for IRMs.3.9 A permanent IRM Steering Committee within Subcom-mittee D11.20 shall be constituted by Subcommittee D11.90 inconsultation with Committee D24 to assist in the utilization
39、 ofthis practice and to make technical and, where required, policydecisions regarding the preparation and administration of IRM.The IRM Steering Committee shall have members of bothCommittees D11 and D24.4. Preparation of Industry Reference Materials4.1 Basic Preparation Steps:4.1.1 An IRM should be
40、 prepared in a way that ensures thatthe entire quantity or lot of the material is as homogeneous, incomposition and vital performance properties, as is possible.4.1.2 For particulate and liquid materials this implies athorough physical blending operation during or after themanufacturing steps, or bo
41、th.4.1.3 For materials not easily blended after manufacture,two options to ensure homogeneity are recommended:4.1.3.1 Use highly homogeneous components or other ma-terials that are required in the manufacturing steps or conductcertain blending operations at intermediate manufacturingsteps to ensure
42、maximum homogeneity.4.1.3.2 Use intensive statistical quality control proceduresto ensure a specified degree of homogeneity among thepackets, bales, or other discrete units of the material.4.1.4 Examples, as cited in 4.1.3.1, are such materials asaccelerators, antioxidants, sulfur, and reference tes
43、t (liquid)fuels.4.1.5 Examples, as cited in 4.1.3.2, are various syntheticrubbers.4.2 Packaging of Industry Reference Materials:4.2.1 Industry reference materials should be packaged pref-erably in small quantities or packages. The packages shall beconsecutively numbered as they are filled. Nominally
44、 the sizeshould be the smallest amount that the average user of thematerial would require for normal volume testing. High vol-ume users could therefore order multiple package lots. The useof such minimum volume (mass) packages will of course vary,but Annex A1 gives recommended masses or volumes.4.2.
45、2 Industry reference materials shall be suitably pack-aged to prevent or retard the change of IRM values with thepassage of time or inadvertent exposure to heat, light, moisture,or combinations thereof, in normal storage. The stringency ofthis requirement varies with the type of IRM. All precautions
46、shall be taken to make IRMs as stable as possible.4.2.3 Packages shall be dispensed by the manufacturing ordistribution organization with a document that shall furnish thefollowing general information:4.2.3.1 Name and number of the IRM,4.2.3.2 Name of the manufacturer,4.2.3.3 Date of manufacture or
47、preparation,4.2.3.4 Storage conditions, and4.2.3.5 Reference to ASTM research report for documenta-tion of testing.4.2.4 For each test property measured to assess lot qualityreport the following:4.2.4.1 Accepted reference value,4.2.4.2 Test lot limits, and4.2.4.3 Between-laboratory limits.4.3 Packag
48、ing of CommonSource Reference Materials:4.3.1 CRMs shall be packaged and dispensed in the samemanner as for IRMs. Each CRM package shall be furnishedwith a documentation sheet with the following information:4.3.1.1 Name and number of the CRM,4.3.1.2 Name of manufacturer,4.3.1.3 Date of manufacture o
49、r preparation,4.3.1.4 Storage conditions, and4.3.1.5 Reference to ASTM research report.5. Overview of Industry Reference Material Testing5.1 Testing is conducted to (1) demonstrate the uniformityof the IRM lot to some selected limits and evaluate the test lotlimits, and (2) to establish an accepted reference value for thelot and as a secondary goal to evaluate the between-laboratorylimits for interlaboratory testing of the IRM where this isapplicable.5.2 Testing for Homogeneity:5.2.1 Homogeneity testing is ideally conducted in onehighly qualified laboratory, which is
