1、Designation: D4678 15aStandard Practice forRubberPreparation, Testing, Acceptance, Documentation,and Use of Reference Materials1This standard is issued under the fixed designation D4678; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () 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 vitally
3、 important toconduct product, specification, and development testing in therubber industry. This practice describes the steps necessary toensure that any candidate material, that has a perceived need,can become a Reference Material. The practice sets forth therecommendations on the preparation steps
4、 for these materials,on the testing that shall be conducted to permit acceptance ofany candidate material, and on how the documentation neededfor the acceptance shall be recorded for future use and review.1.2 This practice shall be administered by ASTM Commit-tee D11.1.2.1 Important sections of this
5、 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 7Typical Reference Material Use 8Recommended Package Size for IRM Annex A
6、1Recommended 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 Reference ValueAnnex A4Statistical Model(s) for IRM Testing Annex A5Example of Annex Calculations for a Typical IRM Appendix X1T
7、wo-Way Analysis of Variance for Calculating Sr Appendix X21.3 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-bil
8、ity of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesD5900 Specification for Physical and Chemical Properties ofIndustry Reference Materials (IRM)E1
9、22 Practice for Calculating Sample Size to Estimate, WithSpecified Precision, the Average for a Characteristic of aLot or ProcessE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE826 Practice for Testing Homogeneity of a Metal Lot orBatch in Solid Form
10、by Spark Atomic Emission Spec-trometry3. 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 operations in therubber industry. They are especially valuable for refere
11、epurposes.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 according to a specified production processto generate a uniform lot; the parameters that defin
12、e 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 established property (parameter) values; theknowledge of a common or single source is sufficient force
13、rtain less critical applications.1This 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 July 1, 2015. Published August 2015. Originallyapproved in 1987. Last previo
14、us edition approved in 2015 as D4678 15. DOI:10.1520/D4678-15A.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 websit
15、e.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.2 Industry reference materials (IRMs) are divided intoadditional classes and types according to the method ofevaluating the lot parameters and according to the productionprocess fo
16、r generating the lot material. These are explainedmore 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:3.2.3.1 Accepted Reference Value (AR Value)An averageIRM property or parameter val
17、ue established by way of aspecified test program.3.2.3.2 Test Lot Limits (TL Limits)These are limits definedas 63 times the standard deviation of individual IRM testresults across the entire lot for the property or parameter(s) thatdefines lot quality; the measurements are conducted in thelaboratory
18、 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-typicalportions in assessing the homogeneity of the lot is done on thebasis of 62 time
19、s 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; howeverthe AR value may be obtained in one of two ways to produceone of two classes of A
20、R 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 obtained inone laboratory or at one location, usually the laboratoryresponsible for prepa
21、ration 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 establish anAR-value are not equivalent to a system or population typicalof industri
22、al 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 onlyrandom variations that cannot be removed. Thus, the recom-mended limits on all
23、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 completedocumentation is supplied to justify the limits.3.2.6 The homogeneity or u
24、niformity 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 blendingthe IRM portions or parts that constitute the lot, to ensure ahigh degree of uniform
25、ity 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-form or highest level of homogeneity that can be attained bythe use of a specified
26、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 uniformity that is attained by the use ofa specified test formeasuring the parameter
27、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 Laboratory Self EvaluationThe IRM may beused in a given laboratory (or with a giv
28、en 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 EvaluationThe IRM may be usedbetween two or more laboratories to determine if the tests
29、ystems 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 performance.3.3.4 Reference liquid IRMs may be used for immersiontesting of various candid
30、ate 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 known as “test bias:” a difference between two(or more) laboratories that is essent
31、ially 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 a corrected test result; this corrected value is used as themeasure of performance
32、 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 as the arithmetic mean.3.5 The various characteristics of IRMs and CRMs(categories
33、, classes, types) are listed in summary form in Table1.3.6 This practice and the IRM program it describes wasdeveloped to replace a standardization program conducted byTABLE 1 Categories of Reference MaterialsAIRM CRMAR Value Global Local NoneHomogeneity Type B Type NB Type B Type NB Single Source(T
34、L Limits) (UL-1) (UL-2) (UL-1) (UL-2) Materialor (UL-1) or (UL-1)AAR value = accepted reference value.TL limits = test lot limits.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
35、.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.See Annex A3 and Annex A4 for more information.D4678 15a2the National Institute of Standards and Technology (NIST) thatbegan in 1948 and has been phased out.3.7 It is not fea
36、sible to write into this practice all thenecessary specifications, modes of preparation, sampling, andtesting protocols, for the wide variety of materials that willeventually become IRM. Therefore this practice is published togive general guidelines for IRMs.3.8 A permanent IRM Steering Committee wi
37、thin Subcom-mittee D11.20 shall be constituted by Subcommittee D11.90 toassist in the utilization of this practice and to make technicaland, where required, policy decisions regarding the preparationand administration of IRM.4. Preparation of Industry Reference Materials4.1 Basic Preparation Steps:4
38、.1.1 An IRM should be 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 themanuf
39、acturing steps, or both.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 manufact
40、uringsteps to ensure 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, sulf
41、ur, and reference test (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
42、are filled. Nominally 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 m
43、asses or volumes.4.2.2 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
44、 IRM. All precautionsshall 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 Da
45、te of manufacture or 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-laborat
46、ory limits.4.3 Packaging 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
47、Date of manufacture or 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 e
48、stablish 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 usual
49、ly the laboratory ofthe organization that produces the IRM. The lot size isdetermined and samples are drawn from the lot. Guidance forthe size and number of samples is given in Annex A2. Thesamples taken from the lot are tested according to the instruc-tions given in Annex A3. This latter annex also addresses theconcept of different uniformity levels for an IRM and theimportance of this in IRM development and use.5.2.2 It is important that each sample represents a fraction orportion of the total lot that can be physically separated from theremainder of the lot, in t
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