ASTM D4213-96(2003)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D4213–96(Reapproved2003)
Standard Test Method for
Scrub Resistance of Paints by Abrasion Weight Loss
This standard is issued under the fixed designation D 4213; 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 E 180 Practice for Determining the Precision of ASTM
Methods for Analysis and Testing of Industrial and Spe-
1.1 This test method covers an accelerated procedure for
cialty Chemicals
determining the resistance of paints to erosion caused by
E 691 Practice for Conducting an Interlaboratory Study to
scrubbing. (Note:The term wet abrasion is sometimes used for
Determine the Precision of a Test Method
scrubbing, and wet abrasion resistance or scrubbability for
scrub resistance.) Although scrub resistance tests are intended
3. Summary of Test Method
primarily for interior coatings, they are sometimes used with
3.1 Thematerialundertestisappliedtoablackplasticscrub
exterior coatings as an additional measure of film performance.
testpanel,andafterdryingoneweek,asectionofthetestpanel
1.2 The values stated in SI units are to be regarded as the
is placed in a straight-line abrasion tester, adjacent to a similar
standard. The values given in parentheses are for information
section of a standard calibration panel. The two sections are
only.
scrubbed simultaneously to produce essentially identical abra-
1.3 This standard does not purport to address all of the
sion experiences and the amount of erosion loss in each section
safety concerns, if any, associated with its use. It is the
determined from the panel weights before and after scrubbing.
responsibility of the user of this standard to establish appro-
3.2 The scrub resistance on a dry-film basis is calculated as
priate safety and health practices and determine the applica-
the percent ratio of the weight loss of the calibration panel to
bility of regulatory limitations prior to use.
that of the test panel. From that value, scrub resistance is
2. Referenced Documents calculated on the basis of both dry- and wet-film volume.
2.1 ASTM Standards:
4. Significance and Use
D 562 Test Method for Consistency of Paints Measuring
4.1 Interior paint films often become soiled, especially near
Krebs Unit (KU) Using a Stormer-Type Viscometer
doorways, windows, and play areas, and frequently need to be
D 1193 Specification for Reagent Water
cleaned by scrubbing. This test method covers the determina-
D 1475 Test Method for Density of Liquid Coatings, Inks,
tion of the relative resistance of paints to erosion when
and Related Products
scrubbed.
D 2486 Test Methods for Scrub Resistance of Wall Paints
4.2 The precision of scrub resistance measurements in
D 3450 Test Method for Washability Properties of Interior
absolute physical values, such as Test Methods D 2486 cycles-
Architectural Coatings
to-failureorthistestmethod,microlitresper100cycles,ispoor
D 3980 Practice for Interlaboratory Testing of Paint and
due to the relatively large effect of subtle and difficult-to-
Related Materials
control variables in test conditions. The test method described
D 4828 Test Methods for Practical Washability of Organic
herein minimizes this problem by using a standard calibration
Coatings
panel as an integral part of each scrubbing operation and
E 70 Test Method for pH of Aqueous Solutions with the
relating its weight loss to that of the paint film under test to
Glass Electrode
establish the latter’s scrub resistance.
NOTE 1—The numerical scrub resistance values obtained by this test
method are of significance only in relation to the specific calibration panel
This test method is under the jurisdiction of ASTM Committee D01 on Paint
types with which the value is obtained. Thus, for example, a scrub
and Related Coatings, Materials, andApplications and is the direct responsibility of
resistance value of 83 with a Type X calibration panel would be reported
Subcommittee D01.42 on Architectural Coatings.
as 83X.
Current edition approved Dec. 1, 2003. Published December 2003. Originally
e1
approved in 1983. Last previous edition approved in 1996 as D 4213 – 96 .
4.3 Results obtained by this test method do not necessarily
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
represent the scrub resistance that might be determined if the
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
test film is allowed to dry before testing appreciably longer
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. than the seven-day period specified herein.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D4213–96 (2003)
4.4 Results obtained by this test method do not necessarily 5.7 Drawdown Plate, 6-mm ( ⁄4-in.) thick, clear float glass,
relate to ease of soil or stain removal (also referred to as size adequate to be used as a base for drawdowns on the
“cleanability” or “cleansability”). To test for those character- specified scrub test panels.
istics use Test Methods D 3450 and D 4828. 5.8 Non-Abrasive Scrub Medium, standard wetting liquid.
, ,
7 8 9
Formula and preparation instructions are as follows:
Formula—Parts by Weight
A
Water, reagent, Specification D 1193, Type IV 89.6
Hydroxyethyl cellulose 2.0
Detergent 4.0
Trisodium phosphate, anhydrous 4.0
B
Acetic acid glacial 0.3
Preservative 0.1
100.0
A
Vary to achieve a final consistency of 165 to 220 g (75 to 85 Krebs Units) with
a Stormer viscometer in accordance with Test Method D 562.
B
Vary to achieve a final pH from 9.5 to 10.0 in accordance with Test Method
E 70.
FIG. 1 Alignment of Panels for Scrubbing
5.8.1 Slowly add the hydroxyethyl cellulose to the water
while stirring mechanically. Stir until uniform and then slowly
add 2 to 3 drops of 28 % ammonium hydroxide solution while
5. Apparatus and Materials
mixing, and continue mixing until the solution turns clear. In
5.1 Straight-line Scrub Tester, set for 37 6 1 cycles per
the order shown, add the other ingredients separately, stirring
minute, having a minimum intrinsic stroke length of 255 mm
continuously. Be sure each item is uniformly dispersed before
(10 in.), counter for recording the number of scrub cycles, base
addingthenextone.Finally,addthepreservativeandadjustthe
pan, glass support plate, “Lilly” frame, and C-clamps to hold
pH with glacial acetic acid.
down the entire test assembly.
NOTE 3—When a referee test is made the medium should be freshly
5.2 Sponge Holder, stainless steel construction, weight: 450
prepared, or from a previously unopened container that is no more than
610g,approximateinsidedimensions:22by75by95mm( ⁄8
1-year old.
by3by3 ⁄4 in.).
5.9 Analytical Balance With Windshield Enclosure, reading
5.3 Polyurethane Sponges, skin free, open-cell formation,
3 3 to 0.1 mg and accurate to 1 mg.
density 0.032 to 0.040 g/cm (2 to 2.5 lb/ft ), compression
5.10 Static Shield, a thin gage metal plate, size 110 by 165
(25 %deflection)4.8kPa(0.7psi),widthandlength0.08in.(2
1 1
mm (4 ⁄4 by 6 ⁄2 in.), to be placed on the balance pan when
mm) larger than the sponge holder with which it is to be used,
weighing. A satisfactory shield can be made from 175 to 300
thickness such that when inserted into the sponge holder it
mm (7 to 12 mil) thick aluminum or tinplate.
protrudes about 5 to 6 mm (0.25 in.) beyond the skirt (see Fig.
5.11 Oven, adjusted to 50 to 55°C (120 to 130°F).
1).
5.12 Calibration Panels, prepared in advance using paints
5.4 Abrasive Pad, 6-mm ( ⁄4-in.) thick, cut to same size as
of suitable scrub resistance.
the sponge with which it is to be used.
5.5 Film Caster, with horse shoe frame, clearance 175 µm NOTE 4—The procedure for preparing calibration panels is the same as
described in 6.1 and 6.2 for regular test panels, except that the panels shall
(7 mils), film width approximately 135 mm (5 ⁄4 in.).
beagedsufficientlybeforeusetoensurethattheeffectofadditionalageing
5.6 Black Plastic Panels, dimensions: 0.25 6 10 % by 165
on their scrub resistance is negligible. A period of 6 months has been
by 430 mm (0.01 6 10 % by 6.5 by 17 in.). Level and uniform
found adequate. Earlier use requires that in a given test series all
dull black surface, impervious to and unaffected by water or
calibration panels be the same age.
aliphatic solvents, plasticizer-free, density 1.33 6 0.05 g/cm .
5.13 Pycnometer, for example, “weight-per-gallon” cup.
NOTE 2—With dark colored paints use white panels. These should be
the same as the black except for color, and density: 1.41 6 0.05 g/cm .
Non-Abrasive Scrub Medium—Catalog Item SC-1 available from The Leneta
Company is made in accordance with these requirements.
Hydroxyethyl cellulose having a molar substitution (MS) value from 1.8 to 2.5
and a 2 % solution viscosity in the range of 4400 to 6500 cps.
Iso-octylphenoxy polyethoxyethanol detergent, such as Triton X-100 has been
found satisfactory for this purpose.
1,3,5-triethyl hexahydro-sym-triazine (Vancide TH), obtainable from R. T.
Sponges, available from suppliers of scrub testers, cut to precise size for their Vanderbilt Co., 30 Winfield St., Norwalk, CT 06855, has been found satisfactory.
respective holders. Calibration panels may be prepared by individual laboratories for internal use
Abrasive pad—Scotch-Brite #7448 manufactured by 3M Company, 3M Center and for relating their results to those of associated laboratories. Suitably aged and
Bldg., St. Paul, MN 55144-1000 has been found satisfactory. Pads cut to the correct standardized calibration panels, having “poor,” “good,” and “very good” scrub
size are available from suppliers of scrub testers. resistance are available commercially from the Leneta Company. These are
Scrub Test Panels—Black: Form P121-10N and White: Form P122-10N, identified asTypeA, C, and D respectively.The scrub resistance ofTypeAhas been
available from The Leneta Co., 15 Whitney Rd., Mahwah, NJ 07430, have been foundtobeapproximately35 %ofTypeC,andTypeCapproximately50 %ofType
found satisfactory and are in compliance with requirements stated in 5.6. D.
D4213–96 (2003)
6. Procedure
6.1 Stir the test paint well by hand. (Do not shake). Strain if
necessarytoremoveskinsandlargeparticles.Cleanthesurface
of the glass drawdown plate carefully, then dust the scrub test
panel making sure both sides are free of specks. Immediately
after cleaning and dusting, place the panel on the drawdown
plate (see 5.7) and tape or otherwise fasten it to the far end.
Rub the panel against the plate with a lint free cloth to develop
static attraction.
6.2 Position the applicator at the fastened end of the panel,
with its 7-mil (175-µm) clearance edge down, and evenly
distribute approximately 12 mLof test paint across the front of
the blade. Draw the paint down at a uniform rate of speed. The
rate of application should be fairly slow (3 to 4 s from
beginning to end) to prevent formation of pinholes or holidays
in the film. Air dry for one week in a horizontal position, in a
FIG. 2 Abrasion Boat Components
well ventilated area kept at 23 6 2°C (73 6 3.5°F) and 50 6
10 % relative humidity.
6.11 Distribute an additional 15 mL of scrub medium along
6.3 At the end of the specified drying time cut the panel
the scrub path then start the machine. (No additional scrub
accurately in half with a paper cutter across the short dimen-
medium is required during the test).
sion, and set aside one of the half-sections for a second test.
6.12 Scrub until either one of the two center sections has
Take the other half-section and make two subsections by
been worn down sufficiently for the black substrate to become
cutting again, parallel to and 75 mm (3 in.) from the previous
faintlyvisiblewithoutactualbreak-through.Inanycase,donot
cut.
exceed800cycles.Duringthefirst200cycles(ifbothfilmslast
6.4 Weigh the narrower subsection in grams to four decimal
that long) reverse the direction of the pad every 50 cycles, and
places.Itisessentialwhileweighing,forthestaticshieldtorest
above200cycles,reverseafterevery100,sothatthepadisrun
on the weighing pan and the panel to rest fully and flatly on the
about the same number of cycles in each direction. Record the
static shield.
number of scrub cycles at the stopping point.
NOTE 5—Weighing to four places is needed to ensure accuracy in the
NOTE 7—If the scrub medium obscures the abrasion path, making it
third (viz., to the nearest mg).
difficult to observe the show-thru status of the film, stop the machine at
6.5 Place the two subsections in the machine, on the glass convenient intervals and sweep the surface briefly with a 50-mm (2-in.)
paint brush dampened with water.
supportplate,withthefirst-cutedgeacrosstheexactcenterline
of the scrub path, and the wider subsection positioned so that
6.13 Remove and wash off the two center (narrow) subsec-
the two second-cut edges are adjacent.
tions with tap water. Press them between paper towels to
6.6 Repeat procedures 6.3, 6.4 and 6.5 using the selected
absorb free moisture, then oven-dry for 15 min at 50 to 55°C
calibration panel (see Note 6 below), placing the first-cut edge (120 to 130°F). After drying reweigh the two subsections to
of the calibration panel adjacent to that of the test panel. See
determine their weight losses, recording them as M and M
test n
Fig. 1 for the configuration of the panel subsections on the in grams to four decimal places (“n” indicates identifying letter
support plate at this point.
of the calibration panel type being used in the particular test,
for example M , M , M , etc.).
A C D
NOTE 6—Use a calibration panel type similar in scrub resistance to that
6.14 Starting with 6.3, repeat the subsequent steps with the
of the test paint, unless a single standard is required for a widely varying
other halves of the test and calibration panels, to obtain two
group of paints. In the latter case use calibration panels that can be
sets of weight loss values. For this second test use a fresh pad
characterized as having “good” or intermediate scrub resistance.
and reverse the positions of the test and calibration panel
6.7 Place the Lilly frame (see 5.1) on the panel assembly
sections in the machine.
and clamp it down firmly to prevent any shift in the test
6.15 Determine the density (D) of the paint in g/mL, in
assembly while scrubbing.
accordance with Test Method D 1475.
6.8 Soak the sponge in tapwater and squeeze to a weight of
6.16 Determinethenonvolatilefractionbyweight(N)ofthe
about 20 g, then place it i
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