1、Designation: D2131 97 (Reapproved 2016)Standard Classification forNatural Muscovite Mica Splittings1This standard is issued under the fixed designation D2131; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisio
2、n. 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 specification covers the determination of muscovitemica splittings of standard commercial grades and specifies themaximum all
3、owable physical defects for each grade. It isapplicable to commercially available natural muscovite micasplittings regardless of the basic color of the mica or its source.1.2 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation o
4、nly.1.3 This standard is very similar to ISO 6386. It is expectedthat materials would be classified identically using the criteriaof either standard. The grades shown under “ASTM GradeNo.” in Table 1 and Table 2 are shown under “Old Grade No.”in ISO 6386-1981.2. Referenced Documents2.1 ASTM Standard
5、s:2D351 Classification for Natural Muscovite Block Mica andThins Based on Visual QualityD1711 Terminology Relating to Electrical Insulation2.2 ISO Publications:ISO 6386-1981 Muscovite Mica SplittingsGrading andVisual Classification33. Terminology3.1 For definitions relating to mica and for terms app
6、licableto this standard, refer to Terminology D1711, and Classifica-tion D351.4. Classification4.1 Mica splittings are classified by size, form, and visualquality and properties.4.2 Thirteen grades, based on size and form, are describedas given in Table 1.4.3 Within the grades, up to thirteen catego
7、ries of visualquality may be separately specified, as listed in Section 6. Notall of the visual quality categories are available in all grades.5. Physical Properties5.1 Natural muscovite mica splittings shall meet the sizerequirements specified in Table 1. Classification D351, Table 1and Fig. 1 , de
8、fine more completely the areas and minimumdimensions that define the size grades, and which should beused in conjunction with Table 1 of this specification.5.2 There shall not be more than the maximum allowabletotal defects specified in Table 2 based on percentage weight.Such defects shall not lie p
9、redominantly in any one category.5.3 There shall not be more of any single defect than thepercentages specified where a specific percentage is allowedfor such defect.5.4 There shall not be any foreign matter included amongthe splittings.6. Visual Quality6.1 Where specified, the visual quality shall
10、conform to thedescription of the visual category specified, as given inClassification D351:6.1.1 V-1Clear,6.1.2 V-2Clear and Slightly Stained,6.1.3 V-3Fair Stained,6.1.4 V-4Good Stained,6.1.5 V-5Stained A Quality,6.1.6 V-5.1Stained D351 Quality,6.1.7 V-6Stained B Quality,6.1.8 V-7Heavy Stained,6.1.9
11、 V-8Densely Stained,6.1.10 V-9Black Dotted,6.1.11 V-10Black Spotted,6.1.12 V-11Black Stained, and6.1.13 V-12Black/Red Stained6.2 Refer to Classification D351 for a complete descriptionof the visual quality categories.1This specification is under the jurisdiction of ASTM Committee D09 onElectrical an
12、d Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.19 on Dielectric Sheet and Roll Products (Disbanded 4/2016).Current edition approved May 15, 2016. Published May 2016. Originallyapproved in 1962. Last previous edition approved in 2008 as D2131 97 (2008)1.DOI: 10.
13、1520/D2131-97R16.2For 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 website.3Available from American National Standards
14、Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1TABLE 1 Requirements for Size and Average Thickness of SplittingsNOTE 1Splittings shall not be of the m
15、inimum area specified, but shall contain a fair proportion of sizes throughout the range specified.NOTE 2The areas specified do not refer to the total area of the splittings but to the usable rectangular size that each grade will produce. For example,Grade 5 splittings should be large enough to prov
16、ide rectangular pieces measuring 112 by2,3by2,2by213 in., etc.ASTM Grade Form Size, in.2AMinimumDimension of Us-ableRectangle, in.BThickness of 10Splittings, in.B4 Bookform 6 to 10, excl 112 (38) 0.006 to0.009,inclC5 Bookform 3 to 6, excl 1 (25) 0.006 to0.009,inclC512 Bookform 2Dto 3, excl78 (22) 0.
17、006 to0.009,inclC6 Bookform 1 to 2, excl34 (19) 0.0006to0.010,inclC4 Loose with powder 6 to 10, excl 112 (38) 0.006 to0.009, incl5 Loose with powder 3 to 6, excl 1 (25) 0.006 to0.009, incl512 Loose with powder 112 to 3, excl78 (22) 0.007 to0.010, incl6 Loose with powder 1 to 112, excl34 (19) 0.007 t
18、o0.010, incl6-1st Loose At least 70 % shall be 1 to 112, exclNot more than 3 % shall pass through a screen hav-ing34-in. square openings.0.007 to0.010, incl6 Intermediate Loose At least 60 % shall be 1 to 112, exclAt least 25 % shall be34 to 1Not more than 3 % shall pass through a screen hav-ing58-i
19、n. square openings.0.007 to0.010, incl6-2nd Loose At least 50 % shall be 1 to 112, exclNot more than 5 % shall pass through a screen hav-ing58-in. square openings.0.007 to0.011, incl6-3rd Loose At least 65 % shall have a minimum area of34 in.2Not more than 8 % shall pass through a screen hav-ing58 i
20、n. square openings.0.007 to0.011, incl6-4th Loose At least 30 % shall have a minimum area of12 in.2and100 % shall pass over a screen having14-in. squareopenings.0.007 to0.012, inclA1in.2= 6.45 cm2.B1 in. = 25.4 mm (exact).CMinimum and maximum thickness of a single splitting in the case of bookform s
21、plittings shall be agreed upon between the purchaser and the seller.DUpon agreement between the buyer and the seller, the minimum area may be 112 in.2(9.7 cm2).TABLE 2 DefectsASTMGradeNo.FormUnder-size,%AStain,%BWavi-nessTears,Fracturesand HolesThickSplittings,%ThinSplittingsV cutsRoughorBurredEdges
22、OtherDefectsTotalAllowableDefects,%CMaximumAllowableIndividualDefects,%4 bookform 3DDD,EDDDD,FD15 45 bookform 3, ,15 4512 bookform 3DDD,EDDDD,FD15 46 bookform 5, ,15 54 loose withpowder10DDDDDDD,GD25 75 loose withpowder10DDDDDDD,GD25 7512 loose withpowder10DDDDHHD,GD25 76 loose withpowder10DDD3D,GD2
23、0 76-1st looseI12 35-inter-mediatelooseI16 36-2nd looseI20 46-3rd looseI20 5 looseI8ANot to be included with total allowable defects.BLots that contain more than 2 % of stained splittings in which the sum of the major dimensions of the stains exceed14 in. (6.4 mm) shall not be regarded as meetingthe
24、se standards. No mineral stain shall be permitted in Bookform Splittings. No more than 30 % of the stain in Nos. 4, 5, and 512 Loose with Powder shall be mineral stain.No more than 40 % of the stain in Nos. 6 Loose with Powder, 6-1st, 6-2nd, and 6-3rd Loose, shall be mineral stain.CTo include an eva
25、luation of undersize splittings for other defects.DExamine for the defect listed.ENo hole shall be permitted.FCount as a defect if more than 20 % of the periphery is rough or burred.GSame as FootnoteFexcept 35 %.HDo not examine for the defect listed.IDetermine undersize in accordance with Table 1.D2
26、131 97 (2016)27. Sampling7.1 BookformFifty books shall be drawn at random fromeach case sampled.At least 10 % of the cases in the lot shall besampled.7.2 Loose with PowderA minimum of a 1-oz (28-g)sample from each case sampled shall be taken.At least 10 % ofthe cases in the lot shall be sampled.7.3
27、Method of CalculationSplittings shall be examined fordefects in the order of separate values listed and counteddefective for the first defective characteristic noted. Defects forwhich separate values are not given may be aggregated. Eachgroup shall be weighed to determine the percentage it repre-sen
28、ts of the total sample weight less undersizes (see FootnoteA, Table 2). In computing percentages,12 % or more shall beconsidered 1 %; less than12 % shall be considered zero.8. Keywords8.1 area; bookform; classification; form; grades; loose withpowder; mica splittings; muscovite mica; size; thickness
29、;visual qualityASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of s
30、uch rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for add
31、itional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to t
32、he ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at th
33、e aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 97 (2016)3
