1、Designation: D 2131 97 (Reapproved 2003)An American National StandardStandard Classification forNatural Muscovite Mica Splittings1This standard is issued under the fixed designation D 2131; the number immediately following the designation indicates the year oforiginal adoption or, in the case of rev
2、ision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers the determination of muscovitemica splittings of standard commercial gra
3、des and specifies themaximum allowable 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
4、parentheses are forinformation only.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 6386.2. Referenced
5、 Documents2.1 ASTM Standards:D 351 Classification for Natural Muscovite Block Mica andThins Based on Visual Quality2D 1711 Terminology Relating to Electrical Insulation22.2 ISO Publications:ISO 6386-1981 Muscovite Mica SplittingsGrading andVisual Classification33. Terminology3.1 For definitions rela
6、ting to mica and for terms applicableto this standard, refer to Terminology D 1711, and Classifica-tion D 351.4. 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 t
7、he grades, up to thirteen categories 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. Classificat
8、ion D 351, Table 1and Fig. 1 , define 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 we
9、ight.Such defects shall not lie predominantly 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 spe
10、cified, the visual quality shall conform to thedescription of the visual category specified, as given inClassification D 351:6.1.1 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 Quality,6.1.7 V-6Stained B Quality
11、,6.1.8 V-7Heavy Stained,6.1.9 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 D 351 for a complete descriptionof the visual quality categories.1This specification is under the jurisdiction of ASTM
12、 Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.19 on Dielectric Sheet and Roll Products.Current edition approved March 10, 2003. Published April 2003. Originallyapproved in 1962. Last previous edition approved in 1997 as D 2131 97.
13、2Annual Book of ASTM Standards, Vol 10.01.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7. Sampling7.1 BookformFifty books s
14、hall 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 Method of CalculationSplittings shall be examine
15、dfor defects 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-sents of the total sample weight less undersizes (s
16、ee 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;visual qualityTABLE 1 Requirements for Size and
17、 Average Thickness of SplittingsNOTE 1Splittings shall not be of the minimum 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
18、produce. For example,Grade 5 splittings should be large enough to provide 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
19、6, excl 1 (25) 0.006 to0.009,inclC512 Bookform 2Dto 3, excl78(22) 0.006 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 112to 3, excl78(22) 0.00
20、7 to0.010, incl6 Loose with powder 1 to 112, excl34(19) 0.007 to0.010, 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 be3
21、4to 1Not more than 3 % shall pass through a screen hav-ing58-in. 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
22、in.2Not more than 8 % shall pass through a screen hav-ing58 in. square openings.0.007 to0.011, incl6-4th Loose At least 30 % shall have a minimum area of12in.2and100 % shall pass over a screen having14-in. squareopenings.0.007 to0.012, inclA1 in.2= 6.45 cm2.B1 in. = 25.4 mm (exact).CMinimum and maxi
23、mum thickness of a single splitting in the case of bookform splittings 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).D 2131 97 (2003)2ASTM International takes no position respecting the validity o
24、f 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 such rights, are entirely their own responsibility.This standard is subject to
25、 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 additional standardsand should be addressed to ASTM International Headquarters.
26、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 the ASTM Committee on Standards, at the address shown below.This standard is c
27、opyrighted 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 the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm
28、.org (e-mail); or through the ASTM website(www.astm.org).TABLE 2 DefectsASTMGradeNo.FormUnder-size,%AStain,%BWavi-nessTears,Fracturesand HolesThickSplittings,%ThinSplittingsV cutsRoughorBurredEdgesOtherDefectsTotalAllowableDefects,%CMaximumAllowableIndividualDefects,%4 bookform 3DDD,EDDDD,FD15 45 bo
29、okform 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,GD20 76-1st looseI12 35-inter-mediatelooseI16 36-2nd looseI20 46-3rd looseI20 5 looseI8ANot to be included
30、 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 meetingthese standards. No mineral stain shall be permitted in Bookform Splittings. No more than 30 % of the stai
31、n 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 evaluation 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.D 2131 97 (2003)3
