1、Designation: D6737 12Standard 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 numbe
2、r in parentheses 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
3、withtapered 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
4、of this standard 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. Significan
5、ce and Use3.1 Filaments 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
6、 from the following equipment: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 rea
7、ds accurately the diameter 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 lengt
8、h.4.4 Air Supply, with pressure regulator 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, i
9、t also depends on the filament diameter, sincethin 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
10、 based on conical bundle shape.6. Procedure6.1 Select 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 desir
11、ed range is to fill a 50-mm (2.0-in.) insidediameter tube. 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. Pla
12、ce the larger end of the bundle inside theloop of measuring 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
13、where they do not interfere with the1This test method is under 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
14、. Originally approvedin 2001. Last previous edition approved in 2006 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
15、 Model 047 DXP,34 in. (19.0 mm) bore 7 in. (178mm) stroke, dual acting, heavy duty available from Bimba Manufacturing Company,Monee, IL 60449-0068, or equivalent, has been found suitable for this purpose.4Pi tape14 in.(6mm)6ft(1.8 m) with 0.01 in. graduations. Lufkin modelW606P, or equivalent, has b
16、een found suitable for this purpose.5Steel cylinder machined to diameter of 2.000 by tolerance (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 States1measuring tape. Apply minimal dow
17、nward 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 bund
18、le diameter to the nearest 0.25-mm(0.01-in.) from where the pointer indicates on the Pi tape,shown in Fig. 3.FIG. 1 Apparatus to Measure Bundle DiameterFIG. 2 Assembled Bundle Diameter ApparatusD6737 1226.4 Release the bundle. Reverse the bundle end for end andrepeat 6.3 to measure the smaller end d
19、iameter. Prevent thestrap from moving up from the tip as it tightens.6.5 Repeat steps 6.2-6.4 on the same bundle to gather twosets of measurements on each bundle.6.6 Weigh the sample bundle to the nearest 0.1 g (W). Makesure that the weight excludes the wrap or rubber bands used tohold the filament
20、together.6.7 Measure the lengths of five individual filaments, re-moved from the center of the bundle, to the nearest 0.5-mm(0.02-in.) with a graduated linear scale and average the lengthsto determine bundle length (L).6.8 Calculate the bulk density as described in 7.3, using theaverage of the two m
21、easurements made for each bundlediameter. Bulk density is expressed in g/cm3(g/in3).7. Calculation or Interpretation of Results7.1 The shape of a tapered filament bundle most closelyapproximates that of a frustum of a right circular cone. Afrustum is the part of a solid cone next to the base that is
22、formed by cutting off the top by a plane parallel to the base.7.2 The volume of the tapered bundle can be calculated asfollows:Volume of bundle 5S13DpL R121R1R21R22! (1)where:L = bundle length, in. (cm),R1= larger end bundle diameter, in. (cm),R2= smaller end bundle diameter, in. (cm).In terms of co
23、rresponding bundle diameters:Volume of bundle 5S13DpLS14D D121D1D21D22! (2)7.3 Bulk Density is generally expressed as Weight/Volume.Therefore, the equation for the Bulk Density of a TaperedFilament Bundle becomes:Bulk Density 5 12 3W/L 3p D121D1D21D22!# (3)where:W = bundle weight, g.The Bulk Density
24、 equation above yields results expressed ing/in.3.8. Precision and Bias8.1 PrecisionNot determined.8.2 BiasSince there is no accepted reference materialsuitable for determining the bias for the procedure in TestMethod for measuring Bulk Density of tapered paintbrushfilaments, no statement on bias ca
25、n be made.9. Keywords9.1 bulk density; density; filaments; paint brushASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of a
26、ny 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 andif not revised, either reapproved or withdrawn. Your comments are
27、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, which you may attend. If you feel that your comments have not recei
28、ved 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
29、 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).FIG. 3 Tapered Bundle PlacementD6737 123
