1、Designation: D4802 16Standard Specification forPoly(Methyl Methacrylate) Acrylic Plastic Sheet1This standard is issued under the fixed designation D4802; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、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*1.1 This specification covers monolithic methacrylat
3、e 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
4、of discontinued Fed. Spec.L-P-391D, discontinued Specification D702. Cast Methacrylate PlasticSheets, Rods, Tubes and Shapes, and discontinued Specification D1547,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 is suitable for use as long as careful control isused to eliminate adverse effects on these properties. The use ofrecycled material in type B-1 and B-2 sheet, is not suitable foruse when these properties are adversely affected. The use ofrecycled or regroun
8、d material is not possible for type A-1 andA-2 materials since the sheet is produced directly frommonomerNOTE 2This standard and ISO 7823-1 address the same subjectmatter, but differ in technical content.2. Referenced Documents2.1 ASTM Standards:2D256 Test Methods for Determining the Izod PendulumIm
9、pact Resistance of PlasticsD542 Test Method for Index of Refraction of TransparentOrganic PlasticsD570 Test Method for Water Absorption of PlasticsD618 Practice for Conditioning Plastics for TestingD638 Test Method for Tensile Properties of PlasticsD648 Test Method for Deflection Temperature of Plas
10、ticsUnder Flexural Load in the Edgewise PositionD792 Test Methods for Density and Specific Gravity (Rela-tive Density) of Plastics by DisplacementD883 Terminology Relating to PlasticsD1003 Test Method for Haze and Luminous Transmittanceof Transparent PlasticsD1044 Test Method for Resistance of Trans
11、parent Plastics toSurface AbrasionD1308 Test Method for Effect of Household Chemicals onClear and Pigmented Organic FinishesD3002 Guide for Evaluation of Coatings Applied to Plastics(Withdrawn 2016)3D3359 Test Methods for Measuring Adhesion by Tape TestD3892 Practice for Packaging/Packing of Plastic
12、sE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications2.2 ISO Standard:ISO 7823-1 (E) PlasticsPoly(Methyl Methacrylate)SheetsTypes, Dimensions, and Characteristics43. Terminology3.1 Definitions:1This specification is under the jurisdiction of ASTM Committ
13、ee D20 onPlastics and is the direct responsibility of Subcommittee D20.15 on ThermoplasticMaterials.Current edition approved May 1, 2016. Published May 2016. Originallyapproved in 1988. Last previous edition approved in 2015 as D4802 15.DOI:10.1520/D4802-16.2For referenced ASTM standards, visit the
14、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.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from Ame
15、rican National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.*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 States13.1.1 General
16、The definitions given in Terminology D883are applicable to this specification.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 w
17、arpage, ndistortion in the form of atwist, wrinkle, or scallop occurring 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 typi
18、cally manufac-tured by the cell-casting process. This category represents 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
19、the continuous-casting method. The physical,chemical, and thermal properties are similar to Category A-1sheet. The optical quality is lower than Category A-1 sheet.This category has better thickness control than that of CategoryA-1 sheet.4.1.3 Category B-1Methacrylate sheet manufactured byany of sev
20、eral processes (typically described as continuouslymanufactured sheet). This sheet possesses lower heat,chemical, and stress-craze resistance than Category A-1 andCategory A-2 sheet. It has equivalent or better optical qualityand thickness tolerances than Category A-2 sheet.4.1.4 Category B-2Methacr
21、ylate sheet typically manufac-tured by conventional extrusion 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
22、following are suitable specified finishes ofmethacrylate sheet. The 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 coa
23、ted.4.2.3.1 Finish 3 material can be of any category provided itmeets 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 f
24、or protection of items sensitive tosunlight or UV radiation.4.2.5 Type 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 speci
25、fied, materials will usually contain UVabsorbers only sufficient to 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 specifi
26、ed limits in thisspecification. For purposes of determining conformance 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
27、digits used in expressing thelimiting value, in accordance with the 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
28、with 8.1.7.5.4 Thermal StabilitySheet shall show no evidence ofbubbling 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 propertiess
29、hown in Table 1.5.6 WorkmanshipSheet, as delivered, shall be free fromwarpage, cracks, scratches, blisters, voids, foreign matter, dielines, and other defects that affect appearance or serviceability.5.6.1 Flatness of SheetSheet shall be free from edge kinkwarpage and from edge “S” warp when lying o
30、n a flat surface.Overall bow warp is permitted for all types of 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 disappea
31、rs or becomesbow warp when turned over is permitted.5.6.2 Chips 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 frequenc
32、y greaterthan 1 chip per 0.4 m2(4.3 ft2) of sheet area. Chips less than 0.8mm (0.031 in.) are to be disregarded unless they form aconcentrated pattern that affects serviceability. Chips from 0.8mm (0.031 in.) to the maximum permissible size shall not havea frequency greater than 1 per 0.4 m2(4.3 ft2
33、). Chips out oftolerance in size when knifed off are considered acceptable ifTABLE 1 Finish 3 Abrasion Resistant MaterialProperty Test Method RequirementAbrasion resistance, 100 cycles at500 g loadD1044Haze, max, % 4.0Coating adhesion, percent retention,minsee 8.1.14 Minimum Classification4B, Fig. 1
34、, TestMethods D3359Chemical resistance, visualexaminationD1308 no changeD4802 162the remaining blemish can be removed by polishing, except forFinish 3 sheet which cannot be easily polished. For Finish 3sheet, the maximum permissible chip size shall be 4.75 mm(0.187 in.); all other requirements above
35、 apply except as noted.5.6.2.2 Chips in Sheet of Thicknesses Greater Than 51 mm(2.008 in.)Chips acceptable providing they do not extendmore 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
36、and contaminants less than 0.8 mm (0.031 in.) shall bedisregarded unless they form a concentrated pattern that affectsthe 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
37、(4.3 ft2) of sheet area for thickness up to and 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 lin
38、es that can be removed bypolishing, shall be permitted 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
39、including 51 mm (2.004 in.),defects within 25 mm (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.) are permitted providing they do notextend more than 0.4 mm (0.01
40、6 in.) below the surface. Sideletgoes for unmasked sheets thicker than 6.0 mm (0.236 in.) upto and including 51 mm (2.004 in.) shall be allowed within a 50mm (1.97 in.) band from the untrimmed edge of the sheet. ForFinish 3 sheet, the maximum permissible length for moldscratches shall be 25 mm (0.98
41、4 in.); the maximum permissiblelength for medium or 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 conc
42、entrated pattern that affectsthe serviceability of the sheet. For Finish 3 sheet, the maximumpermissible frequency for allowable scratches and abrasions asdefined above shall be one per 0.4 m2(4.3 ft2) of sheet area.6. Sampling6.1 Unless otherwise indicated in Section 8 or Table 2,select a sample fr
43、om a sheet 3.0 mm thick sufficient todetermine conformance of the material to this specification.TABLE 2 Detail Requirements for Poly(Methyl Methacrylate) Acrylic Plastic SheetProperty Test MethodCategoryA-1 A-2 B-1 B-2Tensile strength, min, MPa (psi) D638 62 (9.0 k) 62 (9.0 k) 62 (9.0 k) 62 (9.0 k)
44、Elongation at break, min, % D638 2222AIndex of refraction D542min: 1.48 1.48 1.48 1.48Amax: 1.50 1.50 1.50 1.50Specific gravity D792min: 1.18 1.18 1.18 1.18Amax: 1.20 1.20 1.20 1.20Luminous transmittance, min, % D10034.5 mm (0.177 in.) #32 mm (1.259 in.) 89 89 89 8932.0 mm (1.259 in.)# 51.0 mm (2.00
45、0 in.) 87 87 87 87Spectral transmittance, max, % see 8.1.12Type UVF only 200 to 390 nm 5 5 5 5All thicknessesType UVT only 290 to 400 nm(3.0 mm, 0.118 in.)290 nm 40 40 40 40310 nm 70 70 70 70340 nm 85 85 85 85400 nm 86 86 86 86Haze, max,% D1003 3333Dimensional tolerance, max:Thickness, % see Table 3
46、 10 5 5Length 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, max, % see 8.1.7 2.8 2.8 . .Transverse: . . 0.0 5.0Machine: . . 3.0 8.0Water absorption, % D570 (24-h method) see Fig. 1 .ADeflection temperature under flexura
47、l load, 1820kPa (264 psi), C (F), minD64812.0 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 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 D2
48、56, Method A 16.0 (0.3) 16.0 (0.3) 16.0 (0.3) 16.0 (0.3)AAFor Category B-2 sheet only, it is acceptable to determine properties on the resin or test specimens molded from the resin from which the sheet is extruded.BNot applicable.D4802 163TABLE 3 Permissible Thickness Variations for Category A-1 Cas
49、tMethacrylate 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 (0.049) +0.152 (0.006)ENAFNAF0.254 (0.010)1.5 (0.059) +0.381 (0.015) +0.610 (0.024) NAF0.483 (0.019) 0.686 (0.027)2.0 (0.079) +0.356 (0.014) +0.559 (0.022) NAF0.508 (0.020) 0.711 (0.028)2.5 (0.098) +0.330 (0.013) +0.533 (0.021) NAF0.533 (0.021) 0.737 (0.029)2.5 (0.100) +0.330 (0.013) +0.533 (0.021 NAF0.533 (0.021)
