1、Designation:D723308(Reapproved 2012)Standard Test Method forTesting Fracture of Level Paintbrush Filaments1This standard is issued under the fixed designation D7233;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last rev
2、ision.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 This test method covers a procedure for determining thenumber of fractures present when paintbrush filaments arebent.1.2 This metho
3、d is applicable only to monofilaments withconsistent longitudinal cross sectional dimensions commonlyreferred to as“level”filaments.1.3 The values derived are in percent fractured filaments.For example,2 fractured out of 18 filaments tested=218or11%.1.4 The values stated in inch-pound units are to b
4、e regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the us
5、er 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 Filaments are clamped in place and bent to a specificdisplacement.While bent and still in the fixture,they areevaluated for fr
6、acture by visually determining whether thefilaments have cracked or been permanently deformed and willnot recover to virtually straight filaments.(See Fig.1 and Fig.2).3.Significance and Use3.1 This method is intended to evaluate filaments for suit-ability of use in paintbrushes prior to manufacture
7、.Filamentfracture resistance is very important because paintbrushes arebent or flexed during painting and it is necessary that thefilaments are not permanently deformed with usage.4.Apparatus24.1 The apparatus for this method is shown in Fig.3.Filaments are secured between two clamps.The handwheel o
8、nthe front of the gauge is rotated to bring the ends of thefilaments toward each other as measured by the dial indicatorat the top of the gauge.4.2 The device is very delicate and care should be used in itsoperation.To prevent instrument damage,the clamps must notbe brought together closer than a re
9、ading of 0.750 in.(19.0mm)on the dial indicator.5.Sampling,Test Specimens and Test Units5.1 Record the polymer type,filament size and filamentcross-sectional shape.5.2 The sample filaments shall be conditioned for one(1)hat 73.5 6 3.5F(23.0 6 2.0C)and 50 65%relative humidity.5.3 The sample filaments
10、 shall be cut to a minimum of 1.5in.(38.1 mm).5.4 The distance between clamps on the test unit shall be 1.0in.(25.4 mm)at a reading of 0.0(zero deflection).(See Fig.4.)6.Procedure6.1 Select three distinct sections of the bundle,box or lot offilaments to be evaluated.Do not include filaments from the
11、perimeter of a bundle.Pull six(6)filaments from each sectionat equally dispersed intervals.6.2 Set the clamps in a parallel horizontal position with thedial indicator set at 0.0(zero deflection).(See Fig.4.)6.3 Place the six(6)filaments in the clamps.Be sure that nofilament overlaps or is on top of
12、another filament.Close clampsto secure.6.4 Rotate the handwheel counterclockwise to deflect thefilaments until the dial indicator reads 0.650 in.(16.5 mm)travel distance(see Fig.5).1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applicatio
13、ns and is the direct responsibility ofSubcommittee D01.61 on Paint Application Tools.Current edition approved Nov.1,2012.Published November 2012.Originallyapproved in 2008.Last previous edition approved in 2008 as D7233 08.DOI:10.1520/D7233-08R12.2The sole source of supply of the assembled fracture
14、gauge test device known tothe committee at this time is T.S.Simms and Co.,33 Bridge Rd.,St.John,NewBrunswick,Canada.If you are aware of alternative suppliers,please provide thisinformation to ASTM International Headquarters.Your comments will receivecareful consideration at a meeting of the responsi
15、ble technical committee,1whichyou may attend.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.5 Immediately inspect each filament for fracture.Frac-tured filaments will exhibit a sharp point of fracture,will bekinked and will not be stra
16、ight(see Fig.1).Filaments withoutfracture will recover to be straight or will exhibit a deformationat the radius of bend(see Fig.2).6.6 Repeat steps 6.2-6.5 for remaining two(2)sets of six(6)filaments.6.7 Report the results as fractured filaments per number offilaments tested.For example,2 fractured out of 18 filamentstested=218or 11%.7.Calculation or Interpretation of Results7.1 Calculate the percent(%)fractured filaments and com-pare results to product specifications.For example,(218)100=11%.7
