1、Designation: D6778 12Standard Classification System and Basis for Specification forPolyoxymethylene Molding and Extrusion Materials (POM)1This standard is issued under the fixed designation D6778; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 of revision, 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. Scope*1.1 This classification system covers polyoxymethylene ma-terials suitable for molding and extr
3、usion. This classificationsystem allows for the use of polyoxymethylene plastic mate-rials that are recycled, reconstituted, recycled-regrind, recov-ered, or reprocessed, or combination thereof, provided that therequirements as stated in this specification are met. It is theresponsibility of the sup
4、plier and the buyer of recycled,reconstituted, recycled-regrind, recovered, or reprocessedpolyoxymethylene plastic materials, or combination thereof, toensure compliance. (See Guide D7209).1.2 The properties included in this standard are thoserequired to identify the compositions covered. Other requ
5、ire-ments necessary to identify particular characteristics importantto specialized applications are to be specified by using suffixesas given in Section 5.1.3 This classification system and subsequent line callout(specification) are intended to provide a means of calling outplastic materials used in
6、 the fabrication of end items or parts.It is not intended for the selection of materials. Materialselection can be made by those having expertise in the plasticfield only after careful consideration of the design and theperformance required of the part, the environment to which itwill be exposed, th
7、e fabrication process to be employed, thecosts involved, and the inherent properties of the material otherthan those covered by this standard.1.4 The values stated in SI units are to be regarded as thestandard.1.5 The following precautionary caveat pertains only to thetest method portion, Section 11
8、, of this classification system.This standard does not purport to address all of the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatoryrequirements pri
9、or to use.NOTE 1This classification system is similar to ISO 9988-1/-2, al-though the technical content is significantly different.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD1600 Terminology for Abbreviated Term
10、s Relating toPlasticsD3892 Practice for Packaging/Packing of PlasticsD4000 Classification System for Specifying Plastic Materi-alsD5630 Test Method for Ash Content in PlasticsD7209 Guide for Waste Reduction, Resource Recovery, andUse of Recycled Polymeric Materials and ProductsD6100 Specification fo
11、r Extruded, Compression Moldedand Injection Molded Polyoxymethylene Shapes (POM)E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications2.2 ISO Standards:3ISO 75-1 PlasticsDetermination of Temperature of De-flection under LoadPart 1: General Test MethodISO 7
12、5-2 PlasticsDetermination of Temperature of De-flection under LoadPart 2: Plastics and EboniteISO 179-1 PlasticsDetermination of Charpy ImpactPropertiesPart 1: Non-instrumented Impact TestISO 294-1 PlasticsInjection Moulding of Test Specimensof Thermoplastic MaterialsPart 1: General Principles,and M
13、oulding of Multipurpose and Bar Test SpecimensISO 527-1 PlasticsDetermination of Tensile PropertiesPart 1: General PrincipalsISO 527-2 PlasticsDetermination of Tensile PropertiesPart 2: Test Conditions for Moulding and ExtrusionPlasticsISO 1133 PlasticsDetermination of the Melt-Mass FlowRate (MFR) a
14、nd the Melt Volume-Flow Rate (MVR) ofThermoplasticsISO 11357-3 PlasticsDifferential Scanning Calorimetry(DSC)Part 3: Determination of Temperature and En-thalpy of Melting and CrystallizationISO 1183 PlasticsMethods for Determining the Density1This classification is under the jurisdiction of ASTM Com
15、mittee D20 onPlastics and is the direct responsibility of Subcommittee D20.15 on ThermoplasticMaterials.Current edition approved May 1, 2012. Published June 2012. Originallyapproved in 2002. Last previous edition approved in 2006 as D6778 - 06. DOI:10.1520/D6778-12.2For referenced ASTM standards, vi
16、sit 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 American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New Yor
17、k, NY 10036, http:/www.ansi.org.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.of Non-Cellular PlasticsPart 1: Immersion Method,Liquid Pyknometer and Titration Method
18、ISO 3167 PlasticsMultipurpose Test SpecimensISO 3451-1 PlasticsDetermination of AshPart 1: Gen-eral MethodsISO 9988-1 PlasticsPolyoxymethylene (POM) Mouldingand Extrusion MaterialsPart 1: Designation System andBasis for SpecificationsISO 9988-2 PlasticsPolyoxymethylene (POM) Mouldingand Extrusion Ma
19、terialsPart 2: Preparation of TestSpecimens and Determination of Properties3. Terminology3.1 The terminology used in this classification system is inaccordance with Terminologies D883 and D1600.4. Classification4.1 Polyoxymethylene materials are classified into groupsaccording to their composition.
20、These groups are subdividedinto classes and grades, as shown in the Basic Property Table(Table POM).D6778 122TABLE POM Polyoxymethylene Materials, Detail Requirements (Natural and Black Color Only)A,B,CGroup Description Class Description Grade DescriptionFlow RateISO 1133,D,EG/10 minMeltingPoint,ISO
21、11357-3FC, minDensity,ISO 1183,g/cm3TensileStrength,ISO 527,GMPa, minTensileModulus,ISO 527HMPa, minCharpyImpactResistance,ISO 179I/1eA, kJ/m2,minDeflectionTemperature,ISO 75/Method AfJ1.82 MPa,C, min01 Homopolymer 1 general purpose andhigh flow1 percent by weight in the form of glass beads, spheres
22、,or balls. The reinforcement letter designations and associatedtolerance levels are shown in Table 1. Form and structure letterdesignations are shown in Table 1A.Table 1A Symbols for the Form or Structure ofFillers and Reinforcing MaterialsSymbol Form or StructureC Chips, cuttingsD Fines, powdersE B
23、eads, spheres, ballsF FiberG GroundH WhiskerK Knitted fabricL LayerM Mat (fabric, thick)N Non-woven (fabric, thin)P PaperR RovingS FlakeT CordV VeneerW Woven fabricYYarnX Not specified4.2.2 Specific requirements for reinforced, filled, lubricatedor special polyoxymethylene materials shall be shown b
24、y asix-character designation. The designation will consist of theletter “A” or “B” and the five digits comprising the cellnumbers for the property requirements in the order as theyappear in Tables A or B.4.2.2.1 Although the values listed are necessary to includethe range of properties available in
25、existing materials, notevery possible combination of the properties exists or can beobtained.4.2.3 When the grade of the basic material is not known ordoes not meet the Table POM requirements, the use of the “0”grade classification shall be used for reinforced materials inthis classification system.
26、NOTE 5An example of this classification for a reinforced polyoxym-ethylene material is given as follows. The specificationPOM0210G25A65380 indicates the following material requirement:POM = Polyoxymethylene (acetal) as found in Terminology D1600,02 = Copolymer (group),1 = General purpose and high fl
27、ow (class),0 = Other (grade),G25 = Glass-reinforced at 25 % nominal level,A = Table A property requirements,6 = Tensile strength, 110 MPa, min,5 = Tensile modulus, 5500 MPa, min,3 = Charpy impact, 3.0 kJ/m2, min,8 = Deflection temperature, 150C, min, and0 = Unspecified.If no properties are specified
28、, the designation would bePOM0210G25A00000.NOTE 6When a grade of polyoxymethylene is not fully identified bya standard callout, it is possible to specify all table properties by the useof an addition of Classification D4000 suffixes. Suffix values will overridethe POM table values.4.3 Table B has be
29、en incorporated into this classificationsystem to facilitate the classification of special materials whereTable POM or Table A does not reflect the required properties.Table B shall be used in the same manner as Table A.NOTE 7The mechanical properties of pigmented or colored poly-oxymethylene materi
30、als can differ from the mechanical properties ofnatural and black polyoxymethylene material, depending on the choice ofcolorants and the concentration. The main property affected is ductility, asillustrated by a reduction in impact strength. If specific properties ofpigmented materials are necessary
31、, Table B should be employed to specifyproperty requirements.NOTE 8An example of a special polyoxymethylene material usingthis classification system is as follows. The designation POM0110B44250indicates:POM = Polyoxymethylene (acetal) as found in Terminol-ogy D1600,01 = Homopolymer (group),1 = Gener
32、al purpose and high flow (class),0 = Other (grade),B = Table B property requirements,4 = Tensile strength, 40 MPa, min,4 = Tensile modulus, 1400 MPa, min,2 = Charpy impact, 2.0 kJ/m2, min,5 = Deflection temperature, 90C, min, and0 = Unspecified.NOTE 9An example of the use of this classification in a
33、 productspecification is found in Specification D6100, subsection 4.2 and TableS-POM.5. Suffix Requirements5.1 When additional requirements are needed that are notcovered by the basic requirements or cell-table requirements,they shall be indicated through the use of suffixes.5.2 A list of suffixes c
34、an be found in Classification SystemD4000 (Table 3) and are to be used for additional requirementsas appropriate. Additional suffixes will be added to thatstandard as test methods and requirements are developed andrequested.6. General Requirements6.1 Basic requirements from the property tables or ce
35、lltables are always in effect unless superseded by specific suffixrequirements, which always take precedence.D6778 1256.2 The plastics composition shall be uniform and shallconform to the requirements specified herein.7. Detail Requirements7.1 The materials shall conform to the requirements inTables
36、 POM, A, and B and suffix requirements, as they apply.7.2 For the purposes of determining conformance, all speci-fied limits for a specification (line callout) based on thisclassification system are absolute limits, as defined in PracticeE29.7.3 With the absolute method, an observed value or acalcul
37、ated value is not rounded, but is to be compared directlywith the limiting value. Conformance or nonconformance isbased on this comparison.8. Sampling8.1 Sampling shall be statistically adequate to satisfy therequirements of 12.4.8.2 A batch or lot shall be constituted as a unit of manufac-ture as p
38、repared for shipment, and can consist of a blend of twoor more “production runs.”9. Specimen Preparation9.1 Test pieces for relevant test methods shall be based onthe injection molded ISO 3167 Type 1A multipurpose testspecimen. The following pieces are to be used for the listedrelevant test methods.
39、 All test pieces are to be tested as moldedand conditioned. Annealing is not allowed.Test Piece Relevant Test MethodISO 3167 Type 1A Bar Tensile strength and modulus byISO 52780 6 2mmby106 0.2 mmby 4 6 0.2 mm cut from thecenter portion of ISO 3167Type 1A BarCharpy impact resistance byISO 179/1eADefl
40、ection temperature byISO 75/Method AfSpecimen approximately10 by 10 by 4 mm cut fromcenter of ISO 3167Type 1A BarDensity by ISO 11839.2 The test specimens shall be molded by injection mold-ing in accordance with ISO 294-1 and ISO 9988-2. Recom-mended processing conditions are shown in Table 2.10. Co
41、nditioning10.1 Test specimens shall be conditioned in the standardlaboratory atmosphere for a minimum of 16 h (Condition16/23/50, Practice D618) before performing the required tests.10.2 Conduct tests in the standard laboratory atmosphere of23 6 2C and 50 6 10 % relative humidity in accordance withP
42、ractice D618.11. Test Methods11.1 Determine the properties enumerated in this classifica-tion system by means of the test methods in 2.11.1.1 The number of tests shall be consistent with therequirements of Section 8 and 12.4.12. Inspection and Certification12.1 Inspection and certification of the ma
43、terial suppliedwith reference to a specification based on this classificationsystem shall be for conformance to the requirements specifiedherein.12.2 Lot-acceptance inspection shall be the basis on whichacceptance or rejection of the lot is made. The lot-acceptanceinspection shall consist of:12.2.1
44、Melt Flow Rate, or12.2.2 Reinforcement content.12.3 Periodic check inspection with reference to a specifi-cation based on this classification system shall consist of thetests for all requirements of the material under the specifica-tion. Inspection frequency shall be adequate to ensure thematerial i
45、s certifiable in accordance with 12.4.12.4 Certification shall be that the material was manufac-tured by a process in statistical control; sampled, tested, andinspected in accordance with this classification system and thatthe average values for the lot meet the requirements of thespecification (lin
46、e callout).NOTE 10The ASTM publication Manual on Presentation of Data andControl Chart Analysis, 7thEdition, stock number MNL7A, providesdetailed information about statistical process control.12.5 A report of test results shall be furnished when re-quested. The report shall consist of the results of
47、 the lot-acceptance inspection for the shipment and the results of themost recent periodic-check inspection. If requested, the reportshall include the percent by weight of recycled, reconstituted,recycled-regrind, recovered, or reprocessed polyoxymethyleneplastic, or combination thereof, as defined
48、in 3.1.47 of GuideD7209.13. Packaging and Marking13.1 The provisions of Practice D3892 apply to packaging,packing, and marking of containers for plastic materials.14. Keywords14.1 acetal; acetal copolymer; acetal homopolymer; acetalterpolymer; classification; classification system; line callout;L-P-
49、392A; MIL-P-46137A (MR); plastic materials; polyform-aldehyde; polyoxymethylene; polyoxymethylene copolymer;polyoxymethylene homopolymer; polyoxymethylene terpoly-mer; POM; recycle; specificationTABLE 2 Conditions for Injection Molding of Test SpecimensMaterialMeltTemperature,CMoldTemperature,CAverageInjectionVelocity, mm/sHomopolymer, MFR 4 215 90 300 6 100Homopolymer, impactmodified, MFR 4 205 90 200 6 100Copolymer impactmodified205 80 200 6 100Copolymer, MFR 4 205 90 140 6 100Copolymer, high modulus, MFR 4 210 100 140 6 100D6778 126APPENDI
