1、Designation: D 4802 02Standard Specification forPoly(Methyl Methacrylate) Acrylic Plastic Sheet1This standard is issued under the fixed designation D 4802; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This specification covers monolithic methacrylate
3、sheetsproduced by various processes. For this specification, meth-acrylate sheet shall be composed of polymerized acrylicmonomers of which at least 80 % shall be methyl methacrylate.NOTE 1This specification is intended to consolidate the requirementsof the Cast Methacrylate Plastic Sheets portion of
4、 discontinued Fed. Spec.L-P-391D, discontinued Specification D 702. Cast Methacrylate PlasticSheets, Rods, Tubes and Shapes, and discontinued Specification D 1547,Extruded Acrylic Plastic Sheet.1.2 This specification is intended to cover acrylic sheet forgeneral-purpose applications. For specialty a
5、pplications con-sult the appropriate use standards.1.3 The following safety hazards caveat pertains only to thetest methods portion, Section 8, of this specification: Thisstandard does not purport to address all of the safety concerns,if any, associated with its use. It is the responsibility of the
6、userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.1.4 Acrylic sheet is used frequently in applications in whichextreme clarity, lack of optical distortion and absence of anyforeign particulate matter are o
7、f primary significance. Re-ground material may be used as long as careful control is usedto eliminate adverse effects on these properties. The use ofrecycled material in type B-1 and B-2 sheet, may have adverseeffects on these properties which would preclude its use inmost cases. The use of recycled
8、 or reground material is notpossible for type A-1 and A-2 materials since the sheet isproduced directly from monomerNOTE 2This standard is similar to ISO 7823-1:1987 (E) in title only.The technical content is significantly different.2. Referenced Documents2.1 ASTM Standards:2D 256 Test Methods for D
9、etermining the Izod PendulumImpact Resistance of PlasticsD 542 Test Methods for Index of Refraction of TransparentOrganic PlasticD 570 Test Method for Water Absorption of PlasticsD 638 Test Method for Tensile Properties of PlasticsD 648 Test Method for Deflection Temperature of PlasticsUnder Flexura
10、l Load in the Edgewise PositionD 792 Test Methods for Density and Specific Gravity (Rela-tive Density) of Plastics by DisplacementD 883 Terminology Relating to PlasticsD 1003 Test Method for Haze and Luminous Transmittanceof Transparent PlasticsD 1044 Test Method for Resistance of Transparent Plasti
11、csto Surface AbrasionD 1308 Test Method for Effect of Household Chemicals onClear and Pigmented Organic FinishesD 2565 Practice for Xenon Arc Exposure of Plastics In-tended for Outdoor ApplicationsD 3002 Guide for Evaluation of Coatings Applied to Plas-ticsD 3359 Test Method for Measuring Adhesion b
12、y Tape TestD 3892 Practice for Packaging/Packing of PlasticsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications2.2 ISO Standard:ISO 7823-1:1987 (E) PlasticsPoly(Methyl Methacrylate)SheetsTypes, Dimensions, and Characteristics33. Terminology3.1 Definitio
13、ns:3.1.1 GeneralThe definitions given in TerminologyD 883 are applicable to this specification.1This specification is under the jurisdiction of ASTM Committee D20 onPlastics and is the direct responsibility of Subcommittee D20.15 on ThermoplasticMaterials.Current edition approved March 10, 2002. Pub
14、lished May 2002. Originallypublished as D 4802 88. Last previous edition D 4802 01.2For 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 pa
15、ge onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.1*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, Unit
16、ed States.3.2 Definitions of Terms Specific to This Standard:3.2.1 bow warp, ndistortion in the form of a simple curveor arc extending across the sheet and displaced from thehorizontal when the sheet is laying flat.3.2.2 edge kink warpage, ndistortion in the form of atwist, wrinkle, or scallop occur
17、ring along the perimeter of thesheet.3.2.3 “S” warp, ndistortion in the form of a compoundcurve or “S” shape caused by a nonuniform change in internalstresses.4. Classification4.1 Categories:4.1.1 Category A-1Methacrylate sheet typically manufac-tured by the cell-casting process. This category repre
18、sents thebest optical-quality sheet. It is characterized by the highestlong-term design stress and the highest degree of chemicalresistance found in methacrylate sheet.4.1.2 Category A-2Methacrylate sheet typically manufac-tured by the continuous-casting method. The physical, chemi-cal, and thermal
19、properties are similar to Category A-1 sheet.The optical quality is lower than Category A-1 sheet. Thiscategory has better thickness control than that of Category A-1sheet.4.1.3 Category B-1Methacrylate sheet manufactured byany of several processes (typically described as continuouslymanufactured sh
20、eet). This sheet possesses lower heat, chemi-cal, and stress-craze resistance than Category A-1 and Cat-egory A-2 sheet. It has equivalent or better optical quality andthickness tolerances than Category A-2 sheet.4.1.4 Category B-2Methacrylate sheet typically manufac-tured by conventional extrusion
21、processes. This sheet is char-acterized by excellent thickness control similar to CategoryA-2 and Category B-1 sheet. This sheet has reduced long-termdesign stress, chemical resistance, optical quality, and thermalstability.4.2 FinishThe following finishes of methacrylate sheetmay be specified. The
22、physical and optical properties in thisspecification are based on Finish 1 material unless otherwisenoted.4.2.1 Finish 1Smooth or polished.4.2.2 Finish 2Patterned, including textures and frosting.4.2.3 Finish 3Abrasion-resistant coated.4.2.3.1 Finish 3 material can be of any category provided itmeet
23、s the requirements of that category plus the additionalrequirements listed in Table 1.4.2.4 Type UVF (UV-Filtering)Materials that contain anultraviolet absorber to limit the transmission of UV radiationthrough the sheet especially for protection of items sensitive tosunlight or UV radiation.4.2.5 Ty
24、pe UVT (UV-Transmitting)Materials that do notcontain any UV absorbers and are used where there is a needto transmit a greater portion of UV radiation.4.2.6 For general-purpose applications neither type need bespecified. If not specified, materials will usually contain UVabsorbers only sufficient to
25、protect the polymer from degrada-tion from exposure to direct sunlight or UV radiation. There areno specific UV-transmission requirements for material ofunspecified type.5. Detail Requirements5.1 The following applies to all specified limits in thisspecification. For purposes of determining conforma
26、nce withthis specification, an observed value or a calculated value shallbe rounded to the nearest 1 MPa (100 psi) for tensile strength,and for all other properties shall be rounded to the nearest unitin the last righthand place of digits used in expressing thelimiting value, in accordance with the
27、rounding method ofPractice E29.5.2 Sheet shall conform to the requirements prescribed inTable 2. In addition, Category A-1 sheet shall conform to thepermissible-thickness variations listed in Table 3.5.3 ShrinkageTest in accordance with 8.1.7.5.4 Thermal StabilitySheet shall show no evidence ofbubbl
28、ing or blistering when tested in accordance with 8.1.8.5.5 Abrasion-Resistant MaterialFinish 3 material(abrasion-resistant coated material) shall meet the requirementsof the substrate material it is designated as and the propertiesshown in Table 1.5.6 WorkmanshipSheet, as delivered, shall be free fr
29、omwarpage, cracks, scratches, blisters, voids, foreign matter, dielines, and other defects that may affect appearance or service-ability.5.6.1 Flatness of SheetSheet shall be free from edge kinkwarpage and from edge “S” warp when lying on a flat surface.Overall bow warp is permitted for all types of
30、 sheet to amaximum of 6.3 mm (0.250 in.) displacement from thehorizontal for each 4-ft length, or fraction thereof, of a sheetunder its own weight when laying in the horizontal position ona flat continuous surface. “S” warp that disappears or becomesbow warp when turned over is permitted.5.6.2 Chips
31、 and Dirt in Sheet:5.6.2.1 Chips in Sheet of Thickness Equal to or Less Than51 mm (2.008 in.)The maximum permissible chip size shallbe 3.2 mm (0.125 in.). Chips that are approximately themaximum permissible size shall not have a frequency greaterthan 1 chip per 0.4 m2(4.3 ft2) of sheet area. Chips l
32、ess than 0.8mm (0.031 in.) are to be disregarded unless they form aconcentrated pattern that may affect serviceability. Chips from0.8 mm (0.031 in.) to the maximum permissible size shall nothave a frequency greater than 1 per 0.4 m2(4.3 ft2). Chips outof tolerance in size may be knifed off and consi
33、dered accept-able if the remaining blemish can be removed by polishing,except for Finish 3 sheet which cannot be easily polished. ForFinish 3 sheet, the maximum permissible chip size shall be4.75 mm (0.187 in.); all other requirements above apply exceptas noted.TABLE 1 Finish 3 Abrasion Resistant Ma
34、terialProperty Test Method RequirementAbrasion resistance, 100 cycles at500 g loadD 1044Haze, max, % 4.0Coating adhesion, percent retention,minsee 8.1.14 Minimum Classification4B, Fig. 1, TestMethods D 3359Chemical resistance, visualexaminationD 1308 no changeD48020225.6.2.2 Chips in Sheet of Thickn
35、esses Greater Than 51 mm(2.008 in.)Chips may be accepted providing they do notextend more than 0.4 mm (0.016 in.) above the surface.5.6.2.3 Dirt and ContaminantsThe maximum permissibledirt and contamination dimension shall be 3.2 mm (0.125 in.).Dirt and contaminants less than 0.8 mm (0.031 in.) shal
36、l bedisregarded unless they form a concentrated pattern that mayaffect the serviceability of the sheet. The maximum permissiblefrequency for dimensions ranging from 0.8 mm (0.031 in.) tothe maximum permissible for each type of sheet shall be 1 per0.4 m2(4.3 ft2) of sheet area for thickness up to and
37、 including12.0 mm (0.472 in.). For Finish 3 sheet the maximumpermissible dimension for dirt and contaminants shall be 4.8mm (0.187 in.); all other requirements above apply.5.6.2.4 Other DefectsMinor defects, such as mold orhandling scratches, or die lines that can be removed bypolishing, shall be pe
38、rmitted provided these are not objection-able individually or in group patterns. Excluding side letgoesfor masked and unmasked sheets in thicknesses greater than 51mm (2.004 in.) and for unmasked sheets that are thicker than6.0 mm (0.236 in.) up to and including 51 mm (2.004 in.),defects within 25 m
39、m (0.984 in.) of the untrimmed edge of thesheet, that do not significantly reduce mechanical strength ofthe sheet, shall be permitted. Side letgoes for sheets thickerthan 51 mm (2.004 in.) may exist providing they do not extendmore than 0.4 mm (0.016 in.) below the surface. Side letgoesfor unmasked
40、sheets thicker than 6.0 mm (0.236 in.) up to andincluding 51 mm (2.004 in.) shall be allowed within a 50 mm(1.97 in.) band from the untrimmed edge of the sheet. ForFinish 3 sheet, the maximum permissible length for moldscratches shall be 25 mm (0.984 in.); the maximum permissiblelength for medium or
41、 heavy handling scratches or abrasionsshall be 50 mm (1.97 in.); the maximum permissible length oflight-handling scratches or abrasions shall be 153 mm (6.024in.); and scratches or abrasions less than 6 mm shall bedisregarded unless they form a concentrated pattern that mayaffect the serviceability
42、of the sheet. For Finish 3 sheet, themaximum permissible frequency for allowable scratches andabrasions as defined above shall be one per 0.4 m2(4.3 ft2)ofsheet area.6. Sampling6.1 Unless otherwise indicated in Section 8 or Table 2,select a sample from a sheet 3.0 mm thick sufficient todetermine con
43、formance of the material to this specification.NOTE 3When 6.0-mm-thickness sheet is not available for samplingfor spectral-transmittance measurement, other thicknesses may be used forsampling with adjustment of the values found to 6.0-mm thickness. SheetTABLE 2 Detail Requirements for Cast Methacryl
44、ate Plastic SheetsProperty Test MethodCategoryA-1 A-2 B-1 B-2Tensile strength, min, MPa (psi) D 638 62 (9.0 k) 62 (9.0 k) 62 (9.0 k) 62 (9.0 k)Elongation at break, min, % D 638 2 2 2 2AIndex of refraction D 542min: 1.48 1.48 1.48 1.48Amax: 1.50 1.50 1.50 1.50Specific gravity D 792min: 1.18 1.18 1.18
45、 1.18Amax: 1.20 1.20 1.20 1.20Luminous transmittance, min, % D 10034.5 mm (0.177 in.) #32 mm (1.259 in.) 89 89 89 8932.0 mm (1.259 in.)# 51.0 mm (2.000 in.) 87 87 87 87Spectral transmittance, max, % see 8.1.12Type UVF only 200 to 400 nm 5 5 5 5(6.0 mm, 0.236 in.)Type UVT only 290 to 400 nm(3.0 mm, 0
46、.118 in.)290 nm 40 40 40 40310 nm 70 70 70 70340 nm 85 85 85 85400 nm 86 86 86 86Haze, max,% D 1003 3333Dimensional tolerance, max:Thickness, % see Table 3 610 65 65Length and width, mm (in.) 0.0, + 6.4 (0.0,+ 0.250)0.0, + 6.4 (0.0,+ 0.250)0.0, + 6.4 (0.0,+ 0.250)0.0, + 6.4 (0.0,+ 0.250)Shrinkage, m
47、ax, % see 8.1.7 2.8 2.8 . .Transverse: . . 0.0 5.0Machine: . . 3.0 8.0Water absorption, % D 570 (24-h method) see Fig. 1Fig. 1 .ADeflection temperature under flexural load, 1820kPa (264 psi), C (F), minD 64812.0 mm (0.472 in.) #24.0 mm (0.944 in.) 88 (190.4) 88 (190.4) 88 (190.4) N/AB24.0 mm (0.944
48、in.) #100 mm (3.937 in.) 93 (199.4) 93 (199.4) N/ABN/ABThermal stability see 8.1.8.1 see 8.1.8.1 see 8.1.8.2 see 8.1.8.2Impact strength, Izod, J/m (ft-lb/in.), min D 256, Method A 16.0 (0.3) 16.0 (0.3) 16.0 (0.3) 16.0 (0.3)AAFor Category B-2 sheet only, properties noted may be determined on the resi
49、n from which the sheet is extruded.BNot applicable.D4802023thicker than 3.0 mm may be selected when agreed upon between thepurchaser and the manufacturer. In that case, it may be necessary tomachine test specimens to 3.2-mm thickness, which is required for sometests.TABLE 3 Permissible Thickness Variations for Category C-1 CastMethacrylate Plastic SheetsNominal Thickness,mm (in.)APermissible Thickness Variation, mm (in.)Size 1BSize 2CSize 3D0.75 (0.030) +0.178 (0.007)ENAFNAF0.229 (0.009)1.0 (0.039) +0.152 (0.006)ENAFNAF0.254 (0.010)1.25 (
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