ASTM D2562-1994(2002)e1 Standard Practice for Classifying Visual Defects in Parts Molded from Reinforced Thermosetting Plastics《增强热固塑料模制部件中可视缺陷的分类的标准操作规程》.pdf

1、Designation: D 2562 94 (Reapproved 2002)e1Standard Practice forClassifying Visual Defects in Parts Molded from ReinforcedThermosetting Plastics1This standard is issued under the fixed designation D 2562; the number immediately following the designation indicates the year oforiginal adoption or, in t

2、he case of revision, 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.e1NOTEEditorially revised 1.2 in March 2002.1. Scope1.1 This practice covers acceptance criteria

3、 for visual in-spection of parts molded from reinforced thermosetting plasticsby compression and transfer molding.1.2 This practice presents word descriptions of possibledefects to serve as a guide for contracts, drawings, productspecifications, and final inspection.1.3 This practice also categorize

4、s different inspection re-quirements for grades of product quality.1.4 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It

5、 is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE 1There is no known ISO equivalent to this practice.2. Acceptance Criteria2.1 The method and frequency of sampling and

6、the allow-able defects may be previously agreed to by the purchaser andthe seller.2.2 Dimensions and TolerancesMolded parts shall beinspected for conformance with the dimensions and tolerancesspecified on the product drawing. Parts with any dimensionsfalling outside the specified limits shall be rej

7、ected.2.3 InsertsAll inserts, nuts, studs, and lugs shall not bedamaged in any way, nor coated with molding materials insuch a way as to impair function or mechanical fit. Threads inmolded-in inserts shall be clean, smooth, and free of nicks,tears, or other damage. There shall be no molding material

8、 orflash on the threads. If necessary, threaded inserts may beretapped to clean them or remove flash. Threads containinglocking features may not be retapped.2.4 Molded-In Threads or Cored Holes Molded-inthreads or cored holes shall be free of visible defects, such asnicks, cracks, shorts, etc. Molde

9、d-in threads may be retappedor repaired unless otherwise specifically noted on the productdrawing.2.5 WorkmanshipWorkmanship shall be in accordancewith good commercial practices.2.6 Critical AreasAreas in which the presence of imper-fections is considered to be detrimental to the proper functionof t

10、he part shall be designated as critical areas. The areas of apart that are critical structurally, aerodynamically, or electri-cally shall be uniform and free of defects as listed in Table 1,if so stated on the product drawing. Critical areas may bedesignated on the product drawing by one of the foll

11、owingmeans,2.6.1 Encircle critical areas, or2.6.2 Cross-hatch areas to designate areas of various levels,or2.6.3 Word description.2.7 Acceptable DefectsUnless otherwise specified, thefollowing defects shall be acceptable in all instances:2.7.1 Ripple SurfaceGenerally occurs in parts moldedfrom long,

12、 glass-fiber-filled, high-impact-type plastics. Such asurface is a phenomenon resulting from the difference inshrinkage between the resin binder and reinforcement.2.7.2 Shrink-MarkAdimple-like depression in the surfaceof a molding where it has retracted from the mold, and whichhas well-rounded edges

13、. A shrink-mark generally occurs onone surface of a part where there is a boss, flange, rib, or otherheavy section on the opposite surface. The shrink-mark may becaused by the difference in total shrinkage when there is asudden change in section along the surface of the part.2.7.3 Resin VoidsApplica

14、ble to chopped fabric-reinforcedmolding compounds only, appearing as multiple surface inter-ruptions which conform to the pattern of the cloth weave. Thisis usually due to an insufficient flow or shrinkage of the resin,1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis t

15、he direct responsibility of Subcommittee D20.18 on Reinforced ThermosettingPlastics.Current edition approved February 15, 1994. Published April 1994. Originallypublished as D 2562 66 T. Last previous edition D 2562 70(1988).1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Cons

16、hohocken, PA 19428-2959, United States.which fails to fill all of the interstices of the fabric reinforce-ment. These defects occur only at the surface layer of resin incontact with the mold.2.7.4 Surface DiscolorationAn apparent nonuniformityof a material, evidenced by the appearance of dark streak

17、s.Surface streaks are frequently caused by incorporation into theplastic of ejector pin lubricant, mold release, or metallic matterabraded from ejector pins.2.7.5 Weld- or Knit-LinesMarks on, or weaknesses in, amolded plastic, formed by the union of two or more streams ofplastic flowing together, th

18、at do not result in a break orinterruption of the molded surface.2.8 Allowable DefectsDefects which, by nature, content,or frequency, do not affect serviceability of the part. Theseallowable defects shall be fully described as to type, size,number, extent allowed, and spacing. The appropriate accep-

19、tance level (Table 1) for defects in these areas must bespecified. Defects in excess of those listed as allowable in theproduct specifications, drawings, or contracts for the part shallbe cause for rejection.2.9 Repairable DefectsRepairable defects, if any, shallconsist of those which can be repaire

20、d without affecting theserviceability of the part, unless otherwise specifically prohib-ited on the product drawing.Acceptable methods of repair shallTABLE 1 Allowable DefectsName DefinitionVisual Acceptance LevelsLevel I Level II Level IIIChip a small piece broken off an edge or surface none maximu

21、m dimension of break, 3.0mm (18 in.)maximum dimension ofbreak, 6.5 mm (14 in.)Crack an actual separation of the part, visible onopposite surfaces, and extending through thethicknessnone none noneCrack, surface crack existing only on the surface of the part none maximum length, 3.0 mm (18 in.) maximu

22、m length, 6.5 mm(14 in.)Crazing fine cracks at or under the surface of a part none maximum diameter of crazing, 13mm (12 in.)maximum diameter ofcrazing, 25 mm (1 in.)frequency to be determined by customerFracture rupture of the plastic surface withoutcomplete penetrationnone maximum dimension, 21 mm

23、 (1316in.) in diametermaximum dimension, 29 mm(118 in.) in diameterAir bubble air entrapment within and between thereinforcement, usually spherical in shapenone maximum diameter, 1.5 mm (116in.); 2 per in.2maximum diameter, 3.0 mm(18 in.); 4 per in.2Blister rounded elevation of the surface of a part

24、,with boundaries that may be more or lesssharply defined, somewhat resembling inshape a blister on the human skinnone maximum diameter, 3.0 mm (18in.); height from surface not to beoutside drawing tolerancemaximum diameter, 6.5 mm(14 in.); height from surfacenot to be outside drawingtoleranceOrange-

25、peel uneven surface somewhat resembling anorange peelnone maximum diameter, 13 mm (1732in.)maximum diameter, 29 mm(118 in.)Pimple small, sharp, or conical elevation on thesurface of a partnone none maximum diameter, 3.0 mm(18 in.)Pit (pinhole) small crater in the surface of the part, with itswidth a

26、pproximately of the same order ofmagnitude as its depthnone maximum diameter, 0.25 mm(0.010 in.); depth less than 10 %of wall thicknessmaximum diameter, 0.50mm (0.020 in.); depth lessthan 20 % of wall thicknessfrequency to be determined by customerPorosity presence of numerous visible pits (pinholes

27、) none maximum of 25 pits in porousarea of size listed in Level IImaximum of 50 pits inporous area of size listed inLevel IIIWeld- or knit-linea mark on a molded plastic part formed bythe union of two or more streams of plasticflowing togethernone allowable only if surface is not brokenDry-spot area

28、 of incomplete surface film where thereinforcement has not been wetted with resinnone maximum dimension, 10 mm (1332in.)maximum dimension, 13 mm(1732 in.)Foreign inclu-sion (metal-lic)metallic particles included in a part which areforeign to its compositionnone none, if for electrical use;maximum di

29、mension, 0.8 mm (132in.), 1 per 0.09 m2(1 ft2), if formechanical usenone, if for electrical use;maximum dimension, 1.5mm (116 in.), 1 per 0.09m2(1 ft2), if for mechanicaluseForeign inclu-sion (non-metallic)nonmetallic particles of substance included ina part which seem foreign to its compositionnone

30、 maximum dimension, 0.8 mm (132in.); 1 per 0.09 m2(1 ft2)maximum dimension, 1.5mm (116 in.); 1 per 0.09m2(1 ft2)Resin-pocket an apparent accumulation of excess resin ina small localized area within the partnone maximum diameter, 3.0 mm (18in.)maximum diameter, 5.0 mm(316 in.)Short in a laminate, an

31、incompletely filled outcondition.NoteThis may be evident either throughan absence of surface film in some areas, oras lighter unfused particles of materialshowing through a covering surface film,accompanied possibly by thin-skinnedblisters.none none noneD 2562 94 (2002)e12have been agreed to previou

32、sly by the purchaser and the seller,and shall be fully described on the product specifications,drawings, or contracts for parts.3. Acceptance Levels3.1 Visual InspectionEach part shall be checked visuallywithout the aid of magnification. Defects shall be classified asto type and level, as shown in T

33、able 1 (see Note 2). Theacceptable quality level shall be determined by reference to thepart drawing for the applicable acceptance level for allowabledefects. If none of the first three levels (Levels I, II, and III) isconsidered applicable, the level shall be Level IV, and allow-able defects must b

34、e specified on the product drawing. Anyexcess of defects, as specified under the required level, shall because for rejection. Unless otherwise specified, dimensions aresurface dimensions.NOTE 2Typical defects as outlined in the word descriptions of Table1 are illustrated in Fig. .23.2 Acceptance Lev

35、el IPresence of any defects in excessof those listed in Table 1, Level I, shall be cause for rejection.3.3 Acceptance Level IIPresence of more than one defectof those listed in Table 1, Level II, per estimated 10 in.2ofsurface, shall be cause for rejection. No defect area shall be lessthan 2 in. fro

36、m another.3.4 Acceptance Level IIIPresence of more than two de-fects of those listed in Table 1, Level III, per estimated 5 in.2of surface area, shall be cause for rejection. No defect areashall be less than 1 in. from another.3.5 Acceptance Level IVAny defect not specifically de-fined by size or sh

37、ape in Levels I, II, and III, which falls intoa category between Levels I and II or Levels II and III, orbeyond Level III, and is considered acceptable, shall bedesignated as Level IV, and shall be specified on the productdrawing. Any such defect shall be fully described as to size,shape, number, ex

38、tent, and spacing on the product drawing,product specification, or contracts for parts.4. Keywords4.1 reinforced thermosetting plastics; visual defects2Full-size (8 by 10-in.) glossy prints of these typical defects are available at anominal charge from ASTM Headquarters. Order Adjunct: ADJD2562.D 25

39、62 94 (2002)e13FIG. 1 Typical Defects (see Table 1)D 2562 94 (2002)e14FIG. 1 Typical Defects (see Table 1) (continued)D 2562 94 (2002)e15ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this sta

40、ndard 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 revision at any time by the responsible technical committee and must be reviewed every five years an

41、dif 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. Your comments will receive careful consideration at a meeting of theresponsible technical committee,

42、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 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 the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 2562 94 (2002)e16