1、Designation: D788 12D788 14Standard Classification System forPoly(Methyl Methacrylate) (PMMA) Molding and ExtrusionCompounds1This standard is issued under the fixed designation D788; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、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.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope Scope*1.1 The purpose o
3、f this classification system is to provide a method of adequately identifying PMMA materials using a systemconsistent with that of Classification System D4000. It further provides a means for specifying these materials by the use of asimple line callout designation.1.2 This classification system cov
4、ers poly(methyl methacrylate) molding and extrusion compounds. These compounds arepolymers based on methyl methacrylate, and at least 70 % of the polymer shall be polymerized from methyl methacrylate.1.3 The properties in this classification system are those required to identify the compositions cov
5、ered. Other requirementsnecessary to identify particular characteristics important to specific applications shall be described by using the suffixes as givenin Section 5.1.4 Acrylic molding and extrusion compounds are used frequently in applications where extreme clarity and the ability to retaintha
6、t clarity and color under severe weathering and other environmental exposures are of primary significance. While the testspecimen properties of this document extend to the evaluation of nonvirgin materials, the user must take precautions to ensure thatparts made from these materials meet the desired
7、 end-use requirements. Accordingly, this specification allows for the use of thoseacrylic plastic materials that can be recycled, reconstituted, and reground provided the following:1.4.1 The requirements as stated in this specification are met,1.4.2 The material has not been modified in any way to a
8、lter its conformance to food contact regulations or similar requirements,and1.4.3 The requirements of the particular end-use application are met.1.5 This classification system and subsequent line callout (specification) are not intended for the selection of materials, but onlyas a means to call out
9、plastic materials to be used for the manufacture of parts. The selection of these materials is to be made bypersonnel with expertise in the plastics field in which the environment, inherent properties of the materials, performance of theparts, part design, manufacturing process, and economics are co
10、nsidered.NOTE 1This classification system is similar to ISO 8257-1:1987 in title only. The technical content is significantly different.1.6 The values stated in SI units are to be regarded as standard.1.7 This standard does not purport to address all of the safety concerns, if any, associated with i
11、ts use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D149 Test Method for Dielectric Breakdown Voltage and Dielectric Strength
12、 of Solid Electrical Insulating Materials atCommercial Power FrequenciesD150 Test Methods for AC Loss Characteristics and Permittivity (Dielectric Constant) of Solid Electrical Insulation1 This classification system is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct respon
13、sibility of Subcommittee D20.15 on ThermoplasticMaterials.Current edition approved Aug. 1, 2012Aug. 1, 2014. Published September 2012September 2014. Originally approved in 1944. Last previous edition approved in 2012 asD788D788 12. - 11. DOI: 10.1520/D0788-12.10.1520/D078814.2 For referencedASTM sta
14、ndards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an
15、ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as publish
16、ed by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1D257 Test Methods for DC Resistance or Conductance of Insulating Mat
17、erialsD618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD1003 Test Method for Haze and Luminous Transmittance of Transparent PlasticsD1238 Test Method for Melt Flow Rates of Thermoplastics by Extrusion PlastometerD1600 Terminology for Abbreviated Terms Relating
18、to PlasticsD3641 Practice for Injection Molding Test Specimens of Thermoplastic Molding and Extrusion MaterialsD3892 Practice for Packaging/Packing of PlasticsD4000 Classification System for Specifying Plastic MaterialsE29 Practice for Using Significant Digits in Test Data to Determine Conformance w
19、ith Specifications2.2 ISO Standards and Recommendations:3ISO 179 PlasticsDetermination of Charpy Impact PropertiesPart 1: Non-Instrumented Impact TestISO 294 PlasticsInjection Moulding of Test Specimens of Thermoplastic MaterialsPart 1: General Principles, and Mouldingof Multipurpose and Bar Test Sp
20、ecimensISO 306 PlasticsThermoplastic MaterialsDetermination of Vicat Softening TemperatureISO 489 PlasticsDetermination of the Refractive Index of Transparent PlasticsISO 527 PlasticsDetermination of Tensile PropertiesISO 1133 PlasticsDetermination of the Melt Flow Rate of ThermoplasticsISO 3167 Pla
21、sticsPreparation and Use of Multipurpose Test SpecimensISO 8257-1 PlasticsPoly(Methyl Methacrylate) (PMMA) Moulding and Extrusion MaterialsPart 12.3 SAE Standards:4SAE J576 SEP86SAE Recommended Practice for Plastic Materials for Use in Optical Parts such as Lenses and Reflectors forMotor Vehicle Lig
22、hting DevicesSAE J1885 AUG87SAE Recommended Practice for Accelerated Exposure of Automotive Interior Trim Components Usinga Controlled Irradiance Water Cooled Xenon Arc ApparatusSAE J1960 JUN89SAE Standard for Accelerated Exposure of Automotive Exterior Materials Using a Controlled IrradianceWater C
23、ooled Xenon Arc Apparatus3. Terminology3.1 DefinitionsThe terminology used in this classification system is in accordance with Terminologies D883 and D1600.4. Basis of Classification4.1 Poly(methyl methacrylate) molding and extrusion compounds are classified into groups in accordance with theircompo
24、sition. These groups are subdivided into classes and grades as shown in Table 3. A complete classification must includereference to melt-flow rate, as discussed in 4.2 and 5.1.4.4.1.1 To facilitate the incorporation of future or special materials, the “other/unspecified” category (0) for group, clas
25、s, andgrade is given in Table 3.4.1.2 When the grade of the basic material is not shown, or is not important, the use of “0” grade classification shall be usedin this classification system.4.2 The melt-flow rate can vary within a given group, class, and grade and can overlap classes or grades. For t
26、his reason, themelt-flow rate shall be specified using Suffix V.3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.4 Available from SAE International (SAE), 400 Commonwealth Dr., Warrendale, PA 15096-0001, http:/www.sae.or
27、g.TABLE 1 Transmission of Grade 2 Materials at VariousWavelengthsA,BWavelength, nm Transmission, min, %400 86340 85310 70290 50280 26270 12A Measured with UV spectrophotometer using an integrating sphere and a samplethickness of 3.2 mm.B These requirements are in addition to the luminous transmittan
28、ce requirementsgiven in Table 3.D788 1424.2.1 Although the values listed in Suffix V are necessary to include the range of properties available in existing materials, usersmust not infer that every melt-flow rate exists for each class or grade.NOTE 2An example of this classification system is as fol
29、lows:The designation PMMA0112 indicates:PMMA = poly(methyl methacrylate) as found in Terminology D1600,01 = unmodified (group),1 = minimum 77C Vicat, etc. (class) and2 = ultraviolet transmitting (grade).(See Note 4 for a more complete example.)NOTE 3Major industries using these materials now require
30、 internationally accepted test methods for product specifications. For this reason, ISO testmethods have been used in Table 3 and elsewhere in this classification system where appropriate. Similar ASTM standards have been listed in Section2. Many of these ASTM standards are now or soon will be equiv
31、alent. In future editions, a note in the ASTM standard will indicate the degree ofequivalency with a particular international standard. The corresponding ASTM test method is to be substituted as long as the specimen size and all otherconditions of the test method noted in this classification system
32、as applying to the ISO test method are also applied to the ASTM standard.4.3 Grade 1 materials are used where special ultraviolet transmission, filtering, or stabilization characteristics are not required.4.4 Grade 2 materials are used for those specialized applications in which the greatest amount
33、of transmission of UV light isrequired. The transmission properties are given in Table 1.4.5 Grade 3 materials (transparent UV stabilized or transparent UV absorbing) are used when either special resistance to slightcolor change over long exposure times or high-intensity UV radiation is required, or
34、 when the material is required to filter outultraviolet light. These applications are varied and require specific light transmission or color-stability properties to be specifiedby the user.5. Suffixes5.1 When additional requirements are needed, based on the application, that are not covered by the
35、basic cell-table requirements,they shall be indicated through the use of suffixes. In general, suffixes consist of a suffix letter, which gives the requirement needed,a first digit, which gives the test condition, and a second digit, which gives the specific requirement.5.1.1 Suffix E = Electrical r
36、equirements, as designated by the following digits:TABLE 2 Electrical Properties of Unmodified PMMAProperty TestMethod RequirementInsulation resistance, min, Mohm D257 1 107Dielectric strength min, kV/mmA D149 13.8Dielectric constant at 1 MHz, max D150 4.5Dissipation factor at 1 MHz, max D150 0.05A
37、kV/mm 25.4 = V mil.D788 143TABLE 3 PMMA Poly(Methyl Methacrylate) Materials Detail RequirementsNoteThe values listed were developed for natural colors. Colorants or other additives, or both, have the potential to alterthese properties.Group Description Class DescriptionA Grade DescriptionACharpyImpa
38、ct,TestMethodISO 179BkJ/m2, minTensileStrength,TestMethodISO 527,CDMPa, minLuminousTransmittance,Test MethodD1003,DE%, minHaze,TestMethodD1003,DE%, maxIndex ofRefraction,TestMethodISO 489DETensileModulus,TestMethodISO 527,CMPa, minVicatSofteningTemperature,Test MethodISO 306,EFC, min01 UnmodifiedF 1
39、 Formerly 1 General purpose . 58 90 2.5 1.48-1.50 2700 7701 UnmodifiedG 1 Formerly 1 General purpose . 58 90 2.5 1.48-1.50 2700 77Grade 5 2 UV transmittingG . 58 90 2.5 1.48-1.50 2700 77Grade 5 2 UV transmittingH . 58 90 2.5 1.48-1.50 2700 77(D788 - 84) 3 UV stabilizedH . 58 90 2.5 1.48-1.50 2700 77
40、(D788 - 84) 3 UV stabilizedI . 58 90 2.5 1.48-1.50 2700 772 Formerly 1 General purpose . 62 90 2.5 1.48-1.50 2700 86Grade 6 2 UV transmittingG . 62 90 2.5 1.48-1.50 2700 86Grade 6 2 UV transmittingH . 62 90 2.5 1.48-1.50 2700 86(D788 - 84) 3 UV stabilizedH . 62 90 2.5 1.48-1.50 2700 86(D788 - 84) 3
41、UV stabilizedI . 62 90 2.5 1.48-1.50 2700 863 Formerly 1 General purpose . 65 90 2.5 1.48-1.50 2700 95Grade 8 2 UV transmittingG . 65 90 2.5 1.48-1.50 2700 95Grade 8 2 UV transmittingH . 65 90 2.5 1.48-1.50 2700 95(D788 - 84) 3 UV stabilizedH . 65 90 2.5 1.48-1.50 2700 95(D788 - 84) 3 UV stabilizedI
42、 . 65 90 2.5 1.48-1.50 2700 954 Higher VicatSofteningPoint thanFormerGrade 81 General purpose . 65 90 2.5 1.48-1.50 2700 1042 UV transmittingG . 65 90 2.5 1.48-1.50 2700 1042 UV transmittingH . 65 90 2.5 1.48-1.50 2700 1043 UV stabilizedH . 65 90 2.5 1.48-1.50 2700 1043 UV stabilizedI . 65 90 2.5 1.
43、48-1.50 2700 10402 Impact 1 1 1.2 51 88 4.0 1.48-1.50 2600 95modifiedI 0 Other/unspecified. . . . . . .modifiedJ 0 Other/unspecified. . . . . . .2 1 2.0 38 88 4.0 1.48-1.50 2500 903 1 4.3 31 88 4.0 1.48-1.50 1700 854 1 3.0 31 88 4.0 1.48-1.50 1700 8503Heat-ResistancemodifiedJ1 1 General purpose . 65
44、 90 2.5 1.48-1.50 2700 11303 Heat-Resis-tancemodi-fiedK1 1 Generalpurpose. 65 90 2.5 1.48-1.50 2700 1132 UV trans-mittingG. 65 90 2.5 1.48-1.50 2700 1132 UV transmittingH . 65 90 2.5 1.48-1.50 2700 1133 UVstabi-lizedH. 65 90 2.5 1.48-1.50 2700 1133 UVstabi-lizedI. 65 90 2.5 1.48-1.50 2700 1134 Impac
45、t modified also tbd 56 88 4.0 1.48-1.50 tbd 1132 1 General purpose . 65 90 2.5 1.48-1.50 2700 1222 UV transmittingG . 65 90 2.5 1.48-1.50 2700 1222 UV transmittingH . 65 90 2.5 1.48-1.50 2700 1223 UV stabilizedH . 65 90 2.5 1.48-1.50 2700 1223 UV stabilizedI . 65 90 2.5 1.48-1.50 2700 12200 Other 0
46、0 Other/unspecified . . . . . . .ANo descriptions are listed unless needed to describe a special grade or class. All other categories are listed by requirements.BPreferred test specimens are 4 Method designation shall be ISO 179/1eA. Specimen shall be type 1 (4 by 10 by 80 mm 80 mm) with a type A no
47、tch radius of 0.25 mmwith 8-mm depth below notch (Type 1) and are tested by MethodA. When necessary, to fit existing equipment, these specimens must be cut to 63.5-mm length.Annealingis neither required nor prohibited.0.25 mm and shall positioned edgewise for impact. Specimens shall be conditioned i
48、n an oven for 16 hours at a set temperature that is25C below the Vicat softening temperature.C Test specimens are tensile bars with dimensions corresponding to the ISO 3167 multipurpose test specimen, tested at a crosshead speed of 1 mm/min to obtain tensilemodulus. As an option, the crosshead speed
49、 is increased to 5mm/min to obtain the tensile strength value when the test specimen has reached a minimum of 0.3 %elongation.Annealing is neither required nor prohibited.Method designation shall be ISO 527-2/1A/1. Specimens shall be type 1Aand tested at 1 mm/min. Specimens shallbe conditioned in an oven for 16 hours at a set temperature that is 25C below the Vicat softening temperature.DMethod designation shall be ISO 527-2/1A/5. Specimens shall be type 1A and tested at 5 mm/min. Specimens shall be conditioned in an oven for 16 hours at a settemp
