ASTM D5426-2008 866 Standard Practices for Visual Inspection and Grading of Fabrics Used for Inflatable Restraints《充气减震织物的外观检查和等级评定的标准实施规程》.pdf

1、Designation: D 5426 08Standard Practices forVisual Inspection and Grading of Fabrics Used for InflatableRestraints1This standard is issued under the fixed designation D 5426; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year

2、 of last revision. 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 These practices cover procedures for the inspection andgrading of coated and uncoated woven flat and one-piecewove

3、n (OPW) fabrics, and for the inspection and culling of cutparts made of such fabrics, all of which are used in themanufacture of inflatable restraint cushions.1.2 For ease of reference, the scope, summary of practice,significance and use, apparatus, sampling, procedure, andreport sections are listed

4、 separately for each inspection prac-tice.Inspection Practice SectionFabric Rolls 7Cut Pieces subsequently, pieces will be cut fromthe rolls and those pieces that contain imperfections restrictedin Tables 1-5 will be culled at that time.5.5 The accuracy in the results from visually inspectingfabric

5、using these practices is affected by the ability of theinspector to detect, identify, and evaluate the severity of animperfection in a moving fabric or in a cut part. Such abilitycan be affected by visual acuity, viewing distance, fabrictraverse speed, lighting conditions, inspector discipline andtr

6、aining, and the availability and accuracy of suitable visualaids.TABLE 3 DiscolorationImperfection DefinitionLimitsMaximum SizeAMinimumSeparationMaximumFrequencyBStain an area of discoloration that penetrates the fabric surface mustbe from a known source which is demonstrated to have noadverse effec

7、t on fabric properties or the presence ofmarking ink in an area of fabric not provided for identificationby an applicable specification.3-mm diameteror15 mm diameter10 per 400 cm2or2 per 400 cm2Yarn streak discoloration or stain of an individual yarn that does not affectadjacent yarns1000-mm lengthc

8、umulative1AFor diameter call outs, an equivalent area is permissible.BPer linear m (yd) or unit of area indicated. For cut pieces, limits apply to cut pieces # 2 meters in longest dimension. For cut pieces 2 meters in longest dimension,multiply limits by 1.5.TABLE 4 MiscellaneousImperfection Definit

9、ionLimitsMaximum SizeAMinimumSeparationMaximumFrequencyBHole an opening not characteristic of the normal weave patternwhere one or more yarns is cut, torn, or shiftednone allowedMissing yarn a yarn discontinuity resulting in a change in weave pattern none allowedAFor diameter call outs, an equivalen

10、t area is permissible.BPer linear m (yd) or unit of area indicated. For cut pieces, limits apply to cut pieces # 2 meters in longest dimension. For cut pieces 2 meters in longest dimension,multiply limits by 1.5.TABLE 5 Weave Non-UniformityImperfection DefinitionLimitsMaximum SizeAMinimumSeparationM

11、aximumFrequencyBAbrasion a localized concentration of multiple broken filaments. none allowedFold over a hard ridge where a layer is overlapped upon itself where ifapplicable coating integrity is compromisednone allowedLong float a warp or filling yarn extending over six or more filling or warpyarns

12、 with which it should be interlacednone allowedShort float a warp or filling yarn extending over five or fewer filling or warpyarns with which it should be interlaced5 per 400 cm2nonewithin the linewhere two OPWinflatable layersinterfaceBruise a shift in the squareness of the weave pattern in an are

13、a thathas been subjected to impact or pressure35-mm diameter 500 mm 2Tight yarn a yarn with less crimp than surrounding fibers that may createpuckering, which may appear to be shinier or to lie straighterin the weave pattern, or a combination thereof35-mm length 500 mm 2Misweave a change in the weav

14、e pattern visually indicated by incorrectinterlacing or incorrect insertion of a single unbroken yarn ora single missing yarn. (includes mispick, missing yarn,wrong draw, jerk-in).)1000-mm length 1Filling bar a temporary change in the filling-wise density of the weavepattern that:(synonym: stop/star

15、t mark)1. is in compliance with the specified count no limit2. is not in compliance with the specified count none allowedStitching (OPW only) the presence of an inter-lace between two layersof fabric in an area not provided for interlacing by anapplicable specification.none allowedAFor diameter call

16、 outs, an equivalent area is permissible.BPer linear m (yd) or unit of area indicated. For cut pieces, limits apply to cut pieces # 2 meters in longest dimension. For cut pieces 2 meters in longest dimension,multiply limits by 1.5.D54260835.6 Systematic bias may result from using these practiceswhen

17、ever the precision or scale of the visual aids used toidentify and quantify imperfections differs between the pur-chaser and supplier.6. Visual Aids6.1 A calibrated measuring device or clear template ofsufficient size to contain an array of circles whose diametersequal the length, diameter, separati

18、on, or area limits listed inTables 1-5, with labeling corresponding to the terminology foreach imperfection: 3, 10, 15, 35, 50, 200, 225, 300, 400 and500 mm. The template should be positioned such that themaximum number of imperfections is captured.6.1.1 Dimensions on the measuring device or templat

19、e shallbe traceable to the National Institute for Standards and Tech-nology (NIST) (or similarly recognized standards facility) viaa master reference standard to ensure accuracy.6.2 Reference photographs of each imperfection listed inTables 1-5 based on ADJD5426.7. Practice for Inspecting Fabric Rol

20、ls7.1 ScopeThis practice describes a procedure for theinspection and grading of coated and uncoated woven fabricsused in the manufacture of inflatable restraint cushions.7.2 Summary of Practice:7.2.1 Rolls of fabric are visually inspected for the presenceof imperfections and graded at an inspection

21、station. Rolls offabric are unwound and rewound as the fabric traverses theinspection station, with provision for interruption of thetraverse for stationary inspection.NOTE 1In accordance with an applicable material specification, fabricis inspected full width or within a specified distance of the o

22、uter edge ofthe selvage, or if its in one-piece woven fabric within a specified distanceof the visible line created where the two inflatable layers initially interlace.7.2.2 Fabric inspectors grade imperfections for severity interms of their size, relative separation, and frequency per unitarea in a

23、ccordance with Tables 1-5 of these practices.7.2.3 A count of imperfections is recorded, and the roll isfurther processed in accordance with the applicable materialspecification.7.3 Significance and Use:7.3.1 This practice for inspecting rolls of fabric is used toidentify imperfections on a unit are

24、a basis and to flag them inaccordance with an applicable material specification.7.3.2 The suitability of a roll of fabric for further use orprocessing is not determined by the presence or severity ofimperfections, but by the limits placed on rolls of fabric, if any,in the applicable material specifi

25、cation.7.3.3 This practice for inspecting rolls of fabric does notdifferentiate between rolls of fabric intended for incorporationin driver side, passenger side, or side impact cushions, or forincorporation in front or rear panels of such cushions.7.3.4 Whenever differences arise between the grading

26、 re-sults reported by the supplier and those determined by thepurchaser, entire rolls of fabric are set aside by the purchaser orsupplier for joint visual inspection and grading. Material isaccepted or rejected subsequently by mutual agreement basedon the criteria in this practice and the applicable

27、 materialspecification.7.4 Apparatus:7.4.1 A suitable fabric inspection machine that provides aflat viewing surface and an interruptible speed-controlledfabric rewind that measures roll length.7.4.2 An overhead, reflected lighting source mounted par-allel to the viewing surface so as to illuminate w

28、ith directperpendicular impinging light rays and a minimum surfaceillumination level of 1075 lux (100 foot candles), and employ-ing fluorescent lamps having a correlated color temperature of4100 to 4500 k with white reflectors and without baffles.7.4.3 Optional side-mounted reflected lighting source

29、 usedto determine how significantly contamination protrudes fromthe surface of fabric in a roll or a cut piece, mounted obliquelyto the viewing surface so as to illuminate with direct impinginglight rays and a minimum surface illumination level of 1075lux (100 foot candles), and employing fluorescen

30、t lampshaving a correlated color temperature of 4100 to 4500 k withwhite reflectors and without baffles.7.4.4 Optional back lighting (transmitted light) or otherauxiliary lighting sources such as ultraviolet sources mountedas necessary for optimal visual detection of imperfections in aparticular fab

31、ric.7.5 SamplingThis practice for inspecting fabric rolls re-quires 100% inspection of the entire length and surface area ofevery roll of fabric used in the manufacture of inflatablerestraint cushions.7.6 Procedure:7.6.1 Visually inspect and grade the face side of the fabricfrom a viewing distance o

32、f 1 m (yd) while the fabric is inmotion.7.6.2 Traverse the fabric longitudinally (warp-wise) throughthe inspection apparatus at a visual inspection speed slowenough to spot imperfections listed in Tables 1-5.7.6.3 Using the reference photographs as guides, inspect thetotal length of each roll, inter

33、rupting the movement to measurethe size, separation, or frequency of each imperfection.7.6.3.1 Flag each imperfection, signaling its location in thevicinity of the imperfection or along the selvage using only themethod described in the material specification. Flagging de-vices or marks may interfere

34、 with subsequent processing. Donot flag imperfections unless the material specification requiresit, and then only in the manner described.7.6.3.2 Unless otherwise specified, if a imperfection extendslonger than 1 m (yd) in the warp direction, flag only itsbeginning and end, but record its entire len

35、gth in the report.7.6.4 Using the clear template and reference photographs asguides, flag imperfections if they are not allowed according toTables 1-5 or if their size, separation, or frequency areexcessive (exceed the limits of Tables 1-5).7.6.4.1 The inspection limits of Tables 1-5 may be relaxed

36、ifpurchaser and supplier mutually agree that experience anddesign considerations allow for imperfections not to be flaggedthat in the absence of such agreement would otherwise beflagged according to the limits listed in Tables 1-5. In suchcase, flag the imperfections if they exceed the relaxed limit

37、s.7.6.5 Record the total length of the roll and the location ofeach imperfection on an inspection report, one roll per report.D54260847.6.6 Record the total count of imperfections for the roll onthe inspection report.Record the total length of the roll and the location of eachimperfection on an insp

38、ection report, one roll per report.7.6.6.1 If more than one imperfection is detected within ameter (yard) of fabric, include only one in the grading counttotal of the entire roll.7.6.6.2 Except for those imperfections listed as having nonumerical limit to their maximum allowable frequency, dis-simil

39、ar imperfections must be separated by a minimum of 500mm.7.6.7 If the material specification establishes a maximumallowable limit for the number of imperfections, adjust the totalcount of imperfections per roll to account for variations in rolllength. Calculate the adjusted count using (Eq 1):Ca5 Ct

40、3 Ls4 Lm(1)where:Ca= adjusted count,Ct= total count recorded,Ls= standard roll length, m (yd), andLm= measured roll length, m (yd).ExampleThe adjusted total count for a 140-m roll of fabricwith a count of seven imperfections adjusted to a standard100-m roll length is 5:Cs5 Ct3 Ls1 Lm5 7 3 100 4 140

41、5 5 (2)7.7 Report:7.7.1 State that the rolls of fabric were inspected as directedin accordance with Practice D 5426.7.7.2 The purchaser and supplier shall determine the exactform of the inspection report, providing the following infor-mation:7.7.2.1 Roll identification and lot traceability,7.7.2.2 N

42、ame of inspector,7.7.2.3 Date of inspection,7.7.2.4 Fabric designation,7.7.2.5 Relevant specification,7.7.2.6 Space for recording imperfections, and7.7.2.7 Deviations from standard practice procedures andapparatus.8. Practice for Inspecting and Culling Cut Parts8.1 ScopeThis practice describes a pro

43、cedure for theinspection and culling of pieces cut from coated and uncoatedwoven fabrics for subsequent incorporation into inflatablerestraint cushions.8.2 Summary of Practice:8.2.1 Prior to being incorporated into inflatable restraintcushions, individual cut pieces of fabric are visually inspectedf

44、or imperfections. Cut pieces containing the imperfectionslisted in Tables 1-5 of these practices are culled from use, andthe remaining parts are approved for incorporation into airbagcushions.8.2.2 Culled pieces are saved for subsequent review by thepurchaser and supplier.8.3 Significance and Use:8.

45、3.1 This practice for inspecting cut parts does not differ-entiate between cut pieces intended for incorporation in driverside, passenger side, or side impact cushions, or for incorpo-ration in front or rear panels of a cushion. Such differentiationmay be allowed by the applicable cushion specificat

46、ion.8.3.2 Whenever differences arise between the grading re-sults reported by the supplier and those determined by thepurchaser, cut pieces of fabric are set aside by the purchaser orsupplier for joint visual inspection and grading. Material isaccepted or rejected subsequently by mutual agreement ba

47、sedon the criteria in this practice.8.3.3 For the purposes of this practice, the terms pieces,parts, and panels are synonymous.8.4 SamplingThis practice for inspecting and culling cutparts requires 100 % inspection of every cut part used in themanufacture of inflatable restraint cushions.8.5 Procedu

48、re:8.5.1 Remove a single cut panel from the stack of parts.Orient the coated side facing the inspector if the fabric iscoated.8.5.2 Hold the panel up to the light or place it on a backlittable top. Using the clear template and reference photographsas guides, reject parts if they contain imperfection

49、s that are notallowed according to Tables 1-5 or if their size, separation, orfrequency are excessive (exceed the limits of Tables 1-5).NOTE 2Experience may indicate that for certain secondary fabriccomponents such as heat shielded and tethers the limitations of Tables 1-5may be too restrictive or not sufficiently restrictive, causing the rejectionof otherwise acceptable parts or acceptance of non-conforming material.In such cases, deviations from Tables 15 shall be in accordance with andreported according to the applicable material specification.8.5.2.1 For front and back faces o