1、Designation:D673712Standard Test Method forBulk Density of Tapered Paintbrush Filaments1This standard is issued under the fixed designation D6737;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 p
2、arentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers a procedure for measuring theweight of filaments per unit volume.1.2 This method is applicable only to monofilament withtapere
3、d longitudinal profiles.1.3 The values given in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.4 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 standa
4、rd to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Summary of Test Method2.1 The weight,length and diameter of a bundle of taperedfilaments are measured,and the bundle density is calculated.3.Significance and Use3.1 Fila
5、ments are available in a variety of cross-sections andmaterials.Ameasure of bulk density permits the brushmaker toestimate the weight of filament required to prepare a givennumber of brushes.4.Apparatus4.1 The apparatus requires some machining,and is as-sembled as shown in Fig.1 from the following e
6、quipment:4.1.1 Air Valve.24.1.2 Miniature Air Cylinder,dual acting,heavy duty.34.1.3 Assorted parts shown in Fig.1 are machined from 304stainless steel and assembled as shown along with the air valveand cylinder just described.The Pi tape4must be fixed in placeso that it reads accurately the diamete
7、r of a metal calibrationstandard that is 50.8-mm(2.00-in.)diameter.The Pi tape ismounted on an adjustable plate for calibration.4.2 Weighing Device,accurate to 0.1 g to weigh the bundle.4.3 Graduated,Linear Scale,accurate to 0.5-mm(0.02-in.)to measure the bundle length.4.4 Air Supply,with pressure r
8、egulator set for 40 psig.4.5 Calibration Standard,50.8-mm(2.00-in.)in diameter.55.Sampling,Test Specimens and Test Units5.1 The test result depends on the cross-sectional shape,thepolymer,and the length of the bundle selected for the test.Toa lesser extent,it also depends on the filament diameter,si
9、ncethin filaments pack more efficiently than large ones.5.2 The device,as pictured in Fig.1,is designed to measurediameters ranging from 30.5 to 52.3 mm(1.20 to 2.06 in.).Make sure that both ends to be measured are within this range.5.3 Calculations are based on conical bundle shape.6.Procedure6.1 S
10、elect a sample bundle of approximately 50-mm(2.0-in.)diameter.Filament may be removed from a sample so thebundle diameter falls within the scale range 30.5 to 52.3-mm(1.20 to 2.06-in.).One convenient method to adjust the samplediameter to the desired range is to fill a 50-mm(2.0-in.)insidediameter t
11、ube.If the sample is too small,like samples may becombined to adjust the bundle diameter to the desired range.6.2 With rubber bands holding the bundle together,roll itbetween the palms of the hands four times to allow thefilaments to nest.Place the larger end of the bundle inside theloop of measurin
12、g tape in the device shown in Fig.2.6.3 Gently tap the top of the bundle to make certain that allfilaments are making contact with the bottom plate.The bundleshould be kept perpendicular to the bottom plate.The rubberbands must be located where they do not interfere with the1This test method is unde
13、r the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.61 on Paint Application Tools.Current edition approved June 1,2012.Published July 2012.Originally approvedin 2001.Last previous edition approved in 200
14、6 as D6737 01(2006).DOI:10.1520/D6737-12.2Air valve such as Model 6676 available from Hunt Valve Co.,1913 E.StateStreet,Salem,Ohio 44460,or equivalent,has been found suitable for this purpose.3Miniature air cylinder such as Model 047 DXP,34in.(19.0 mm)bore 7 in.(178mm)stroke,dual acting,heavy duty a
15、vailable from Bimba Manufacturing Company,Monee,IL 60449-0068,or equivalent,has been found suitable for this purpose.4Pi tape14in.(6 mm)6 ft(1.8 m)with 0.01 in.graduations.Lufkin modelW606P,or equivalent,has been found suitable for this purpose.5Steel cylinder machined to diameter of 2.000 by tolera
16、nce(0.001 by 0.001)in.(50.8 by tolerance(0.02 by 0.02)mm).Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 measuring tape.Apply minimal downward pressure to restrainthe bundle from moving upwards during stabilization andtesting cycles.With the supply pressure to the air valve set at40 psig,operate the air valve lever 10 times with the bundle inplace to stabilize the system.Actuate the air valve to tighten thesteel tape.Read the bundle
