ASTM D7233-08(2012)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D7233 − 08 (Reapproved 2012)
Standard Test Method for
Testing Fracture of Level Paintbrush Filaments
This standard is issued under the fixed designation D7233; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Apparatus
1.1 This test method covers a procedure for determining the 4.1 The apparatus for this method is shown in Fig. 3.
Filaments are secured between two clamps. The handwheel on
number of fractures present when paintbrush filaments are
the front of the gauge is rotated to bring the ends of the
bent.
filaments toward each other as measured by the dial indicator
1.2 This method is applicable only to monofilaments with
at the top of the gauge.
consistent longitudinal cross sectional dimensions commonly
4.2 Thedeviceisverydelicateandcareshouldbeusedinits
referred to as “level” filaments.
operation. To prevent instrument damage, the clamps must not
1.3 The values derived are in percent fractured filaments.
be brought together closer than a reading of 0.750 in. (19.0
For example, 2 fractured out of 18 filaments tested = ⁄18 or
mm) on the dial indicator.
11 %.
5. Sampling, Test Specimens and Test Units
1.4 The values stated in inch-pound units are to be regarded
as standard. The values given in parentheses are mathematical
5.1 Record the polymer type, filament size and filament
conversions to SI units that are provided for information only
cross-sectional shape.
and are not considered standard.
5.2 The sample filaments shall be conditioned for one (1) h
1.5 This standard does not purport to address all of the
at73.5 63.5°F(23.0 62.0°C)and50 65 %relativehumidity.
safety concerns, if any, associated with its use. It is the
5.3 The sample filaments shall be cut to a minimum of 1.5
responsibility of the user of this standard to establish appro-
in. (38.1 mm).
priate safety and health practices and determine the applica-
5.4 Thedistancebetweenclampsonthetestunitshallbe1.0
bility of regulatory limitations prior to use.
in.(25.4mm)atareadingof0.0(zerodeflection).(SeeFig.4.)
2. Summary of Test Method
6. Procedure
2.1 Filaments are clamped in place and bent to a specific
6.1 Select three distinct sections of the bundle, box or lot of
displacement. While bent and still in the fixture, they are
filaments to be evaluated. Do not include filaments from the
evaluated for fracture by visually determining whether the
perimeter of a bundle. Pull six (6) filaments from each section
filamentshavecrackedorbeenpermanentlydeformedandwill
at equally dispersed intervals.
not recover to virtually straight filaments. (See Fig. 1 and Fig.
2).
6.2 Set the clamps in a parallel horizontal position with the
dial indicator set at 0.0 (zero deflection). (See Fig. 4.)
3. Significance and Use
6.3 Place the six (6) filaments in the clamps. Be sure that no
3.1 This method is intended to evaluate filaments for suit- filamentoverlapsorisontopofanotherfilament.Closeclamps
ability of use in paintbrushes prior to manufacture. Filament to secure.
fracture resistance is very important because paintbrushes are
6.4 Rotate the handwheel counterclockwise to deflect the
bent or flexed during painting and it is necessary that the
filaments until the dial indicator reads 0.650 in. (16.5 mm)
filaments are not permanently deformed with usage.
travel distance (see Fig. 5).
1 2
This test method is under the jurisdiction of ASTM Committee D01 on Paint The sole source of supply of the assembled fracture gauge test device known to
and Related Coatings, Materials, andApplications and is the direct responsibility of the committee at this time is T. S. Simms and Co., 33 Bridge Rd., St. John, New
Subcommittee D01.61 on Paint Applicatio
...