ASTM D6737-01

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D6737–01
Standard Test Method for
Bulk Density of Tapered Paintbrush Filaments
This standard is issued under the fixed designation D 6737; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope standard that is 50.8-mm (2.00-in.) diameter. The Pi tape is
mounted on an adjustable plate for calibration.
1.1 This test method covers a procedure for measuring the
4.2 Weighing Device, accurate to 0.1 g to weigh the bundle.
weight of filaments per unit volume.
4.3 Graduated, Linear Scale, accurate to 0.5-mm (0.02-in.)
1.2 This method is applicable only to monofilament with
to measure the bundle length.
tapered longitudinal profiles.
4.4 Air Supply, with pressure regulator set for 40 psig.
1.3 The values given in SI units are to be regarded as the
4.5 Calibration Standard, 50.8-mm (2.00-in.) in diameter.
standard. The values given in parentheses allow for calculating
the bulk density in g/in. , a commonly used form.
5. Sampling, Test Specimens and Test Units
1.4 This standard does not purport to address all of the
5.1 The test result depends on the cross-sectional shape, the
safety concerns, if any, associated with its use. It is the
polymer, and the length of the bundle selected for the test. To
responsibility of the user of this standard to establish appro-
a lesser extent, it also depends on the filament diameter, since
priate safety and health practices and determine the applica-
thin filaments pack more efficiently than large ones.
bility of regulatory limitations prior to use.
5.2 The device, as pictured in Fig. 1, is designed to measure
2. Summary of Test Method diameters 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.
2.1 The weight, length and diameter of a bundle of tapered
5.3 Calculations are based on conical bundle shape.
filaments are measured, and the bundle density is calculated.
6. Procedure
3. Significance and Use
6.1 Select a sample bundle of approximately 50-mm (2.0-
3.1 Filamentsareavailableinavarietyofcross-sectionsand
in.) diameter. Filament may be removed from a sample so the
materials.Ameasure of bulk density permits the brushmaker to
bundle diameter falls within the scale range 30.5 to 52.3-mm
estimate the weight of filament required to prepare a given
(1.20 to 2.06-in.). One convenient method to adjust the sample
number of brushes.
diameter to the desired range is to fill a 50-mm (2.0-in.) inside
4. Apparatus diameter tube. If the sample is too small, like samples may be
combined to adjust the bundle diameter to the desired range.
4.1 The apparatus requires some machining, and is as-
6.2 With rubber bands holding the bundle together, roll it
sembled as shown in Fig. 1 from the following equipment:
between the palms of the hands four times to allow the
4.1.1 Air Valve.
filaments to nest. Place the larger end of the bundle inside the
4.1.2 Miniature Air Cylinder, dual acting, heavy duty.
loop of measuring tape in the device shown in Fig. 2.
4.1.3 Assorted parts shown in Fig. 1 are machined from 304
6.3 Gently tap the top of the bundle to make certain that all
stainless steel and assembled as shown along with the air valve
filaments are making contact with the bottom plate.The bundle
and cylinder just described.The Pi tape must be fixed in place
should be kept perpendicular to the bottom plate. The rubber
so that it reads accurately the diameter of a metal calibration
bands must be located where they do not interfere with the
measuring tape.Apply minimal downward pressure to restrain
This test method is under the jurisdiction of ASTM Committee D01 on Paint
the bundle from moving upwards during stabilization and
and Related Coatings, Materials, andApplications and is the direct responsibility of
testing cycles. With the supply pressure to the air valve set at
Subcommittee D01.61 on Paint Application Tools.
40 psig, operate the air valve lever 10 times with the bundle in
Current edition approved Dec. 10, 2001. Published February 2002.
Air valve such as Model 6676 available from Hunt Valve Co., 1913 E. State
Street, Salem, Ohio 44460, or equivalent, has been found suitable for this purpose.
3 5
Miniature air cylinder such as Model 047 DXP, ⁄4
...