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 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 referred 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 its 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 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, referred 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 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 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, Sieving 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 Definitions:3.1.1 For additional terminology, refer to TerminologyE1638.3.1.2 bubble point test, n—capillary 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.3.1.2.1 Discussion—The pressure observed at the firstbubble location is considered the absolute micron retentionrating (see Test Method F316).3.1.3 cloth thickness, n—overall thickness of the filter cloth,nominally estimated by adding the warp wire diameter plustwo times the shute wire diameter.3.1.4 crimp, n—corrugation in the warp and shute wires.3.1.4.1 Discussion—The crimp in the wires is formed dur-ing the weaving process, and the tension existing between thewarp and shute wires fundamentally determines the respective1This guide is under the jurisdiction of ASTM Committee E29 on Particle andSpray Characterization and is the direct responsibility of Subcommittee 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

[email protected] For Annual Book of ASTMStandards volume information, refer to the standard’s Document Summary page onthe ASTM website.3Available from SAE International (SAE), 400 Commonwealth Dr., Warrendale,PA 15096-0001, http://www.sae.org.Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1amount or depth of crimp, which in part establishes thefirmness of the filter cloth. With the exception of reverse filtercloth, the warp wire is tensioned such that it only crimpsminimally if at all, and the shute wire crimps predominatelyaround the warp wire.3.1.5 filter cake (surface cake), n—material that is retainedon the filter cloth during processing.3.1.5.1 Discussion—The 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 backflushing. The deposition of material forming the filtercake can aid in filtration by providing depth filtration, whichresults in a lower micron retention.3.1.6 glass bead test, n—method for determining the filtra-tion rating of filter cloth using a set of presorted precisely sizedspherical glass beads, passing them through the filter cloth, andexamining the beads passed or captured.3.1.6.1 Discussion—The largest bead passed is consideredthe absolute micron retention rating.3.1.7 mesh, n—number of wires or openings per linear inchor 25.4 mm counted from the center of any wire to a pointexactly 1 in. or 25.4 mm distant, including the fractionaldistance between either thereof.3.1.8 micron, n—common filtration reference to a particlesize, properly defined as a micrometre.3.1.9 micron retention, n—separation particle size of thefilter cloth expressed as a diameter in micrometres.3.1.10 micron retention, absolute, n—diameter of the largestspherical particle that will pass through the filter cloth underlaboratory conditions representing the maximum pore size.3.1.11 micron retention, nominal, n—subject to userdefinition, an indication of the average pore size of the filtercloth.3.1.11.1 Discussion—The 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 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.3.1.12 percent open area, n—because of the irregulartriangular-shaped opening formed at an angle to the plane ofthe filter cloth surface, the percent open area is generally not aspecified parameter.3.1.13 shute wires, n—wires running the short way of, oracross the cloth, as woven (also referred to as the shoot, fill, orweft wires).3.1.14 types of weaves, n—3.1.14.1 double warp, adj—filter cloth (either plain or twill)in which two warp wires are used instead of one for each warppitch thus reducing the micron retention of a similar regularsingle-warp wire specification (see Fig. 1).3.1.14.2 plain, adj—filter cloth in which the shute wirespass over one and under one warp wire (see Fig. 2).3.1.14.3 reverse weave, adj—filter cloth in which the warpand shute wires are woven in a reverse configuration; notcovered within this guide (see Fig. 3).3.1.14.4 twill, adj—filter cloth in which the shute wires passover two and under two wires (see Fig. 4).3.1.15 warp wires, n—the wires running the long way of thecloth as woven.3.1.16 weight per unit area, n—weight per square foot forfilter cloth can be approximated (without consideration for thesignificant crimp of the shute wire) by the following equation:Wt/ft25 @12Mw~12π ~Dw2/4! ρ!#

[email protected]~12π ~Ds2/4! ρ!# (1)where:Wt/ft2= weight (lb) per square foot,Mw= mesh warp,Ms= mesh shute,Dw= diameter warp wire,Ds= diameter shute wire,ρ = density of material (lb/in.3) (0.2836 for stainlesssteel 304),π = constant 3.1416.3.1.16.1 Discussion—The theoretical mass per unit area canbe similarly calculated with SI units or an approximatemultiplier factor of 4.8824 can be used to obtain kilograms persquare metre.3.1.17 wire diameter, n—wire diameter shall be expressed indecimal 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 (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 micronNOTE 1—Reprinted with permission from the Haver 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-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. Packaging and Labeling8.1 Packaging—Depending on the specification, woven fil-ter cloth may be rolled on a wooden or cardboard roll or moredurable specifications without a center roll, but in any case, themethod of packaging should take into account the likelihood ofbeing damaged.Any special packaging should be specified andagreed to with the supplier.8.2 Labeling:8.2.1 Filter cloth should be labeled with the followinginformation:8.2.1.1 The name of the manufacturer;8.2.1.2 The material of the wire;8.2.1.3 The mesh designation of the specification;8.2.1.4 The type of weave; and8.2.1.5 The quantity, that is, length and width, or the sizeand number of pieces.8.2.2 Other labeling requirements may be subject to agree-ment between the customer and the supplier.9. Certification9.1 At the time of ordering, customers may request a testcertificate containing the following information or partsthereof:9.1.1 Chemical Analysis of the Weaving Wires—For thechemical analysis of the material, the wire manufacturer’sbatch, heat, or melt number analysis is applicable.9.1.2 Mesh count or additional tests as agreed between thecustomer and the supplier.10. Keywords10.1 Dutch weave; filter cloth; micron retention; wire clothE2814 − 114ANNEXES(Mandatory Information)A1. CALCULATION OF dTr3FOR SEPARATION PARTICLE SIZE IN ACCORDANCE WITH TITTEL AND BERNDT (1973)4A1.1 For 24 × 110 mesh plain:A1.1.1 Pitch warp wires (t1):t15 1/245 0.0417in. 5 1.0583mmA1.1.2 Warp wire diameter (dk):dk5 0.015in. 5 0.381 mmA1.1.3 Shute wire diameter (ds):ds5 0.010in. 5 0.254mmA1.1.4 Ratio of warp to shute wire diameters (b):b 5 dk/ds5 1.50A1.2 For the “Plane 3” pore triangle:A1.2.1 Base of triangle (g):g 5 ds*S11~11b!2*0.66*~1 2 b*ds/

[email protected]~11b!2*0.436#0.52 1Dg 5 0.2250A1.2.2 Height of triangle (ht):ht5 t1*0.5*S111 2 @11~11b!2*0.436#0.5~11b!2*0.662 ~b*ds/t1!Dht5 0.2194A1.2.3 Particle size (dTr3):dTr35 g*

[email protected]~g/~2*ht!!211#0.52 g/~2*ht!%dTr35 0.137 mm 5 137 µmA2. CALCULATION OF dTr2FOR SEPARATION PARTICLE SIZE IN ACCORDANCE WITHTITTEL AND BERNDT (1973)4WITH BLACKMORE (2009) (Appendix X1)A2.1 For 20 × 250 mesh twill:A2.1.1 Pitch warp wires (t1):t15 1/205 0.050 in. 5 1.270 mmA2.1.2 Warp wire diameter (dk):dk5 0.010 in. 5 0.254 mmA2.1.3 Shute wire diameter (ds):ds5 0.0085 in. 5 0.216 mmA2.1.4 Ratio of warp to shute wire diameters (b):b 5 dk/ds5 1.1765A2.1.5 Ratio of warp pitch to warp wire diameter:t1/dk5 5.00A2.2 For the “Plane 2” pore triangle:A2.2.1 Coordinate origin ratio (t/t1):t/t15 @~11b!213#/@2*~~11b!211!#t/t15 0.6743A2.2.2 Geometric dimension (x):x 5 ds*

[email protected]~11b!617*~11b!417*~11b!211#0.52*~~11b!211!2 1Dx 5 0.1087A2.2.3 Particle size (d0):d05 ds*~$~x/ds11!2/@~x/ds11!22 0.25#0.5% 2 1!d05 0.1283A2.2.4 Correction factor (Z):Z 5 t1/@t122 ds2*~11b!2#0.5Z 5 1.0764A2.2.5 Particle size (dTr2):dTr25 d02 @0.4*ds*~Z 2 1!#dTr25 0.122 mm 5 122 µmE2814 − 115APPENDIXES(Nonmandatory Information)X1. DENNIS BLACKMORE NOTES ON TITTEL AND BERNDT (1973)4Notes on the Tittel-Berndt Filter Fabric ModelDenis BlackmoreDepartment of Mathematical Sciences and Center for Applied Mathematics and Statistics, NJITDecember 21, 2009X1.1 IntroductionX1.1.1 Our purpose is to clarify some points in the modeldeveloped in Tittel and Berndt (1973). In particular, we shalltry to clarify the derivations of Equations (2) and (3) of Titteland Berndt, which we believe are presented in the wrong orderand therefore mislabeled (although ultimately the order isirrelevant). This can be accomplished by imbedding the vari-ous elements of the fabric—namely the basic fabric planes andvarious weft wires (in Figure 3 and Figure 5 of Tittel andBerndt)—in a three-dimensional euclidean coordinate system.X1.2 Euclidean Coordinate Representation of FabricConfigurationX1.2.1 We start by introducing cartesian coordinates(X, Y, Z) in 3-space R3so that the pore plane lies in theXY-plane. More precisely, we position the origin in ourcoordinate system at a point in the pore plane Ƥ midwaybetween the warp wires K1and K2(having diameters dk)sothat the parallel axes of symmetry of these wires are parallel tothe X-axis (the position of the origin corresponds to the darkdot in the upper portion of Figure 5 of Tittel and Berndt(1973)). Then the wires are represented as the solid cylinders:K1: 5HX 5 ~X, Y, Z!:SY 2t12D21Z2#Sdk2D2J(X1.1)K2: 5HX 5 ~X, Y, Z!:SY1t12D21Z2#Sdk2D2Jand the pore plane is characterized by:Ƥ: 5 $X 5 ~X, Y,0!:~X, Y! ϵ R2% (X1.2)X1.2.2 Next we have to find the representations of the weftwires in Figure 3 and Figure 5 of Tittel and Berndt (1973). Weshall denote these cylindrical wires as w1, w2, and w3(eachhaving a common diameter of ds), and describe them withreference to Figure 3 and Figure 5. As the wires are (ideally)cylindrical tubes, they can be specified by their centerlines. Wesee from Figure 5 that the centerline of w1—at least between itsfirst intersection points with K1and K2—has the (parametric)form:ℓ1:X~α! 5Sds2~11α!,~1 2 2α!t12 D2,D2D(X1.3)where:D: 5 ds1dkand the parameter α (not to be confused with the angle inFigure 4 of Tittel and Berndt (1973)) ranges over all realnumbers, and the wire is tangent to K1whenα = α1:= –(2t1)–1D and tangent to K2when α = α2:=1+α1.Similarly, we find from Figure 3 that the centerlines ℓ2and ℓ3of w2and w3, respectively (between their first intersectionpoints with K1and K2), have the parametric forms:ℓ2:X~β! 5 S 2ds2~11β!,~t12 D!2~1 2 2β!, D Œt12 Dt11D~1 2 2β!D(X1.4)ℓ3:X~γ! 5 Sds2~1 2 γ!,~t11D!2~1 2 2γ!,2D Œt11Dt12 D~1 2 2γ!DX1.2.3 We n