1、Designation: E2814 11Standard Guide forIndustrial Woven Wire Filter Cloth1This standard is issued under the fixed designation E2814; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses
2、 indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONIndustrial metal filter cloth is a special type of woven wire cloth that can be produced in manyspecifications, often proprietary in nature. Sometimes refer
3、red to as Dutch weave or Hollander weave,filter cloth can be woven in a variety of metals and is woven with a greater number of wires in onedirection than the other, and utilizing two different wire diameters. This guide covers woven wire filtercloth for industrial use, which is commonly rated by it
4、s micron retention capability. Its purpose is tointroduce standard terms and definitions, to observe common technical considerations that a usershould be aware of, and to present a mathematical model that can be used to predict the micronretention of a filter cloth specification. It should be noted
5、this guide excludes standard industrial wovenwire cloth and sieve cloth from its scope, since these are covered under Specifications E2016 and E11,respectively, as well as excludes plastic and synthetic filter cloth.1. Scope1.1 This guide covers the special grade of industrial wovenwire cloth, refer
6、red to as filter cloth, for general filtrationincluding the separation of solids from fluids (liquids or gases),based on a desired particle size retention. Filter cloth can bemade of any primary metal or metal alloy wire that is suitablefor weaving.1.2 The values stated in inch-pound units are to be
7、 regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the
8、 user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E11 Specification for Woven Wire Test Sieve Cloth and TestSievesE1638 Terminology Relating to Sieves, Sievin
9、g Methods,and Screening MediaE2016 Specification for Industrial Woven Wire ClothF316 Test Methods for Pore Size Characteristics of Mem-brane Filters by Bubble Point and Mean Flow Pore Test2.2 SAE Standards:3ARP901 Bubble-Point Test Method3. Terminology3.1 DefinitionsFor additional terminology, refer
10、 to Termi-nology E1638.3.1.1 bubble point test, ncapillary flow bubble pointmethods are based on the fact that the pressure required toforce an air bubble through filter cloth wetted under a testliquid of known surface tension is inversely proportional to thepore size.3.1.1.1 DiscussionThe pressure
11、observed at the firstbubble location is considered the absolute micron retentionrating (see Test Method F316).3.1.2 cloth thickness, noverall thickness of the filter cloth,nominally estimated by adding the warp wire diameter plustwo times the shute wire diameter.3.1.3 crimp, ncorrugation in the warp
12、 and shute wires.3.1.3.1 DiscussionThe crimp in the wires is formed dur-ing the weaving process, and the tension existing between thewarp and shute wires fundamentally determines the respectiveamount or depth of crimp, which in part establishes thefirmness of the filter cloth. With the exception of
13、reverse filtercloth, the warp wire is tensioned such that it only crimpsminimally if at all, and the shute wire crimps predominatelyaround the warp wire.1This guide is under the jurisdiction of ASTM Committee E29 on Particle andSpray Characterization and is the direct responsibility of Subcommittee
14、E29.01 onSieves, Sieving Methods, and Screening Media.Current edition approved April 1, 2011. Published July 2011. DOI: 10.1520/E2814-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume i
15、nformation, refer to the standards Document Summary page onthe ASTM website.3Available from SAE International (SAE), 400 Commonwealth Dr., Warrendale,PA 15096-0001, http:/www.sae.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.
16、1.4 filter cake (surface cake), nmaterial that is retainedon the filter cloth during processing.3.1.4.1 DiscussionThe filter cake forms and builds up asparticulate is retained, until the increased flow resistance of thefilter cake requires it be removed from the filter cloth, typicallyby backflushin
17、g. The deposition of material forming the filtercake can aid in filtration by providing depth filtration, whichresults in a lower micron retention.3.1.5 glass bead test, nmethod for determining the filtra-tion rating of filter cloth using a set of presorted precisely sizedspherical glass beads, pass
18、ing them through the filter cloth, andexamining the beads passed or captured.3.1.5.1 DiscussionThe largest bead passed is consideredthe absolute micron retention rating.3.1.6 mesh, nnumber of wires or openings per linear inchor 25.4 mm counted from the center of any wire to a pointexactly 1 in. or 2
19、5.4 mm distant, including the fractionaldistance between either thereof.3.1.7 micron, ncommon filtration reference to a particlesize, properly defined as a micrometre.3.1.8 micron retention, nseparation particle size of thefilter cloth expressed as a diameter in micrometres.3.1.9 micron retention, a
20、bsolute, ndiameter of the largestspherical particle that will pass through the filter cloth underlaboratory conditions representing the maximum pore size.3.1.10 micron retention, nominal, nsubject to user defini-tion, an indication of the average pore size of the filter cloth.3.1.10.1 DiscussionThe
21、nominal rating may refer to: (1)the glass bead or particle size the filter cloth will retain 90 % ofby weight; (2) the bubble point pore size when the tenth bubblelocation appears; or (3) the degree of filtration achieved underspecific process conditions such as operating pressure, concen-tration of
22、 contaminant, and the buildup of filter cake, such that94 % to 98 % of all particles of the nominal value will beretained after a given working period.3.1.11 percent open area, nbecause of the irregulartriangular-shaped opening formed at an angle to the plane ofthe filter cloth surface, the percent
23、open area is generally not aspecified parameter.NOTEReprinted with permission from the Haver notcovered within this guide (see Fig. 3).3.1.13.4 twill, adjfilter cloth in which the shute wires passover two and under two wires (see Fig. 4).3.1.14 warp wires, nthe wires running the long way of thecloth
24、 as woven.3.1.15 weight per unit area, nweight per square foot forfilter cloth can be approximated (without consideration for thesignificant crimp of the shute wire) by the following equation:Wt/ft25 12 Mw12p Dw2/4! r!# 1 12 Ms12p Ds2/4! r!#(1)where:Wt/ft2= weight (lb) per square foot,Mw= mesh warp,
25、Ms= mesh shute,Dw= diameter warp wire,Ds= diameter shute wire,r = density of material (lb/in.3) (0.2836 for stainlesssteel 304),p = constant 3.1416.3.1.15.1 DiscussionThe theoretical mass per unit area canbe similarly calculated with SI units or an approximatemultiplier factor of 4.8824 can be used
26、to obtain kilograms persquare metre.3.1.16 wire diameter, nwire diameter shall be expressedin decimal parts of an inch or the metric equivalent.4. Significance and Use4.1 Industrial filter cloth is a specialized product that can bemanufactured in many specifications. The purpose of this guideis to (
27、1) introduce standard terms and definitions associatedwith wire filter cloth, (2) observe common technical consider-ations that a user should be aware of, and (3) present amathematical model that can be used to predict the micronretention of a filter cloth specification. As often numerousspecificati
28、ons may be developed to result in a common micronretention by varying the weave type, mesh count, and wirediameters, it is recommended that the user consult with theirfilter cloth supplier regarding specific filter cloth specificationsof interest and include in their discussions durability, pressure
29、drop, and cleaning capability requirements. The purpose of thisguide is not to suggest a limited selection of specifications.4.2 The micron retention of a filter cloth specification can bemathematically modeled as well as determined by the use of aglass bead test or the bubble-point test method or b
30、othdepending on the degree of fineness. Typical standard bubble-point test methods (porometry) include Test Methods F316 andSAE ARP901.5. Filter Cloth Specifications5.1 Filter cloth is woven in a variation of sometimesproprietary parameters based on often common nominal meshcount specifications. Thi
31、s is due to minor variations in meshcount and wire diameters used to affect micron retention,porosity, and other factors related to specific operating condi-tions, as well as possibly for manufacturing convenience.Therefore, it is not appropriate to provide a comprehensivetable of common filter spec
32、ifications stating constructionrequirements and resulting parameters. Instead, a mathematicalmodel is presented that can be used to predict the micronretention or separation particle size of any filter cloth specifi-cation a user and producer wish to develop.5.2 This mathematical model is presented
33、by Reiner Titteland Rolf Berndt4with further conclusions by Denis Blackmore(see Appendix X1). The model assumes rigid, spherical par-ticles that pass through various planes or cross sections of thefilter cloth created by shute wires stretched around warp wiresand positioned geometrically adjacent to
34、 one another. Theseparation particle size is determined for the applicable geo-metric plane based on the weave type and specification ratios.5.3 While five geometric planes of the filter cloth areconsidered (three of interest as the outer two are symmetrical),Plane 3, designated the geometric middle
35、 plane of the filtercloth, is the primary plane of interest. Accordingly, the sepa-ration particle size (dTr3) is determined for plain weave withwarp wire to shute wire diameter ratios within the range 1.00to 1.50 (see Annex A1). For twill weave with warp pitch towarp wire diameter ratios greater th
36、an 3.22, Plane 2 is consid-ered and the separation particle size (dTr2) is determined. Forthe calculation of dTr2, Blackmore concludes that for theequated Tittel and Berndt equations, the coordinate origin ratio(t/t1) and the geometric dimension (x) can both be expressed asa function of the warp-to-
37、shute-wire diameters (b) (see AnnexA2). The model is not applicable for reverse weave filter cloth.5.4 A selection of typical woven wire filter cloth specifica-tions are presented with their particle size retentions asdetermined by the Tittel and Berndt model in conjunction withthe Blackmore conclus
38、ions (see Appendix X2). These specifi-cations are only for example, as countless others may beconsidered for weaving. Check with a weaver to determine thefeasibility of others. Note that the physical properties of thewire to be woven may have an impact on overall filter clothquality.6. Technical Con
39、siderations6.1 Wire TolerancesThe diameter tolerance for wire be-fore weaving commonly should be in accordance with indus-trial standards. It is recognized that mechanical deformation ofparticularly the shute wire occurs during weaving. Therefore,4Tittel, R. and Berndt, R., “Zur bestimmung der trenn
40、teilchengr e vonfiltergeweben,” Faserforschung und Textiltechnik, Vol 24, 1973, pp. 505510.E2814 113the diameter measured after weaving can only be used as aguide to the original nominal diameter.6.2 Filter Cloth Tolerances:6.2.1 Industrial filter cloth can be woven from a greatvariety of metals and
41、 alloys. Metals other than 300 seriesstainless steel may not be possible depending on the particularspecification and should be discussed with the supplier.6.2.2 Tolerances on parameters such as mesh count andmicron retention should be discussed with the supplier.6.2.3 The shute wires should be stre
42、tched around the warpwires and positioned adjacent to one another. Irregular gapsbetween the shute wires may indicate irregular retentioncapability.6.3 Filter Cloth BlemishesFilter cloth may exhibit someblemishes or defects that are inherent to the weaving process.The permissible number of major ble
43、mishes or defects shouldbe discussed with the supplier.Any irregular opening in an areaof filter cloth, as a result of any various cause, shall beconsidered a defect if the agreed to micron retention isexceeded.6.4 Delivery Requirements:6.4.1 Except when specifically agreed to otherwise, the totalqu
44、antity of filter cloth furnished should be within 610 % of thequantity ordered. The invoice should be based on the actualquantity furnished.6.4.2 A standard roll is 100 linear feet (30.5 m) 6 10 linearfeet (3 m), but each specification should be discussed with thesupplier.6.4.3 The nominal width of
45、the roll should be specified, aswell as the permissible tolerance if applicable, and whether theroll may be delivered with or without selvage edges.6.4.4 The percentage of yield of the filter cloth shall beagreed on with the customer and will vary according to thespecification and size of the produc
46、t.6.4.5 The flatness of woven filter cloth with regard to bothcurl and waviness should be discussed with the supplier.6.4.6 Some filter cloth specifications may exhibit frayededges.6.4.7 Firmness is a subjective term referring to the planarrigidity of filter cloth established by the tensile strength
47、 of thematerial, the relationship of the mesh to wire diameters, thetype of weave, the amount of crimp in the wires, and thetension on the warp wires during the weaving. The absence offirmness in woven wire filter cloth is termed sleaziness. Wovenwire filter cloth should normally exhibit satisfactor
48、y firmness;that may be discussed with the supplier.6.4.8 Woven filter cloth may be covered with a film of oil orother lubricant as a result of the manufacturing process. Thewire may show traces of products used in or markings causedby the drawing process.6.4.9 The tolerances that can be held on cut-
49、to-size pieces offilter cloth can be dependent on the piece size, the mesh, wirediameters, type of weave, and firmness of the weave. Thesefactors should be considered in the discussion of toleranceswith the supplier.7. Procedure7.1 Filter cloth is best inspected using a backlight to observeirregular and defective openings.7.2 The mesh count of filter cloth may be checked using acounting glass compatible with the degree of fineness. All testapparatus should be calibrated against standards traceable tothe National Institute of Standards and Technology.8
