ASTM D4213-08(2012)
(Test Method)Standard Test Method for Scrub Resistance of Paints by Abrasion Weight Loss
Standard Test Method for Scrub Resistance of Paints by Abrasion Weight Loss
SIGNIFICANCE AND USE
4.1 Interior paint films often become soiled, especially near doorways, windows, and play areas, and frequently need to be cleaned by scrubbing. This test method covers the determination of the relative resistance of paints to erosion when scrubbed.
4.2 The precision of scrub resistance measurements in absolute physical values, such as Test Methods D2486 cycles-to-failure or this test method, microlitres per 100 cycles, is poor due to the relatively large effect of subtle and difficult-to-control variables in test conditions. The test method described herein minimizes this problem by using a standard calibration panel as an integral part of each scrubbing operation and relating its weight loss to that of the paint film under test to 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 types with which the value is obtained. Thus, for example, a scrub resistance value of 83 with a Type X calibration panel would be reported as 83X.
4.3 Results obtained by this test method do not necessarily represent the scrub resistance that might be determined if the test film is allowed to dry before testing appreciably longer than the seven-day period specified herein.
4.4 Results obtained by this test method do not necessarily relate to ease of soil or stain removal (also referred to as “cleanability” or “cleansability”). To test for those characteristics use Test Methods D3450 and D4828.
FIG. 1 Alignment of Panels for Scrubbing
SCOPE
1.1 This test method covers an accelerated procedure for determining the resistance of paints to erosion caused by scrubbing. (Note: The term wet abrasion is sometimes used for scrubbing, and wet abrasion resistance or scrubbability for scrub resistance.) Although scrub resistance tests are intended primarily for interior coatings, they are sometimes used with exterior coatings as an additional measure of film performance.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
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: D4213 − 08 (Reapproved 2012)
Standard Test Method for
Scrub Resistance of Paints by Abrasion Weight Loss
This standard is issued under the fixed designation D4213; 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 E70 Test Method for pH of Aqueous Solutions With the
Glass Electrode
1.1 This test method covers an accelerated procedure for
E180 Practice for Determining the Precision of ASTM
determining the resistance of paints to erosion caused by
Methods for Analysis and Testing of Industrial and Spe-
scrubbing. (Note:The term wet abrasion is sometimes used for
cialty Chemicals (Withdrawn 2009)
scrubbing, and wet abrasion resistance or scrubbability for
E691 Practice for Conducting an Interlaboratory Study to
scrub resistance.) Although scrub resistance tests are intended
Determine the Precision of a Test Method
primarily for interior coatings, they are sometimes used with
exterior coatings as an additional measure of film performance.
3. Summary of Test Method
1.2 The values stated in SI units are to be regarded as the
3.1 Thematerialundertestisappliedtoablackplasticscrub
standard. The values given in parentheses are for information
testpanel,andafterdryingoneweek,asectionofthetestpanel
only.
is placed in a straight-line abrasion tester, adjacent to a similar
1.3 This standard does not purport to address all of the
section of a standard calibration panel. The two sections are
safety concerns, if any, associated with its use. It is the
scrubbed simultaneously to produce essentially identical abra-
responsibility of the user of this standard to establish appro-
sion experiences and the amount of erosion loss in each section
priate safety and health practices and determine the applica-
determined from the panel weights before and after scrubbing.
bility of regulatory limitations prior to use.
3.2 The scrub resistance on a dry-film basis is calculated as
the percent ratio of the weight loss of the calibration panel to
2. Referenced Documents
that of the test panel. From that value, scrub resistance is
2.1 ASTM Standards:
calculated on the basis of both dry- and wet-film volume.
D562 Test Method for Consistency of Paints Measuring
KrebsUnit(KU)ViscosityUsingaStormer-TypeViscom-
4. Significance and Use
eter
4.1 Interior paint films often become soiled, especially near
D1193 Specification for Reagent Water
doorways, windows, and play areas, and frequently need to be
D1475 Test Method For Density of Liquid Coatings, Inks,
cleaned by scrubbing. This test method covers the determina-
and Related Products
tion of the relative resistance of paints to erosion when
D2486 Test Methods for Scrub Resistance of Wall Paints
scrubbed.
D3450 Test Method for Washability Properties of Interior
Architectural Coatings
4.2 The precision of scrub resistance measurements in
D3980 Practice for Interlaboratory Testing of Paint and
absolute physical values, such as Test Methods D2486 cycles-
Related Materials (Withdrawn 1998)
to-failureorthistestmethod,microlitresper100cycles,ispoor
D4828 Test Methods for Practical Washability of Organic
due to the relatively large effect of subtle and difficult-to-
Coatings
control variables in test conditions. The test method described
herein minimizes this problem by using a standard calibration
panel as an integral part of each scrubbing operation and
This test method is under the jurisdiction of ASTM Committee D01 on Paint
relating its weight loss to that of the paint film under test to
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.42 on Architectural Coatings.
establish the latter’s scrub resistance.
Current edition approved July 1, 2012. Published August 2012. Originally
NOTE 1—The numerical scrub resistance values obtained by this test
approved in 1983. Last previous edition approved in 2008 as D4213 – 08. DOI:
10.1520/D4213-08R12. method are of significance only in relation to the specific calibration panel
For referenced ASTM standards, visit the ASTM website, www.astm.org, or types with which the value is obtained. Thus, for example, a scrub
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
resistance value of 83 with a Type X calibration panel would be reported
Standards volume information, refer to the standard’s Document Summary page on
as 83X.
the ASTM website.
4.3 Results obtained by this test method do not necessarily
The last approved version of this historical standard is referenced on
www.astm.org. represent the scrub resistance that might be determined if the
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4213 − 08 (2012)
test film is allowed to dry before testing appreciably longer 5.7 Drawdown Plate, 6-mm ( ⁄4-in.) thick, clear float glass,
than the seven-day period specified herein. size adequate to be used as a base for drawdowns on the
specified scrub test panels.
4.4 Results obtained by this test method do not necessarily
relate to ease of soil or stain removal (also referred to as
5.8 Non-Abrasive Scrub Medium, standard wetting liquid.
8-10
“cleanability” or “cleansability”). To test for those character-
Formula and preparation instructions are as follows:
istics use Test Methods D3450 and D4828.
Formula—Parts by Weight
A
Water, reagent, Specification D1193, 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 D562.
B
Vary to achieve a final pH from 9.5 to 10.0 in accordance with Test Method E70.
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
FIG. 1 Alignment of Panels for Scrubbing
mixing, and continue mixing until the solution turns clear. In
the order shown, add the other ingredients separately, stirring
continuously. Be sure each item is uniformly dispersed before
5. Apparatus and Materials
addingthenextone.Finally,addthepreservativeandadjustthe
5.1 Straight-line Scrub Tester, set for 37 6 1 cycles per pH with glacial acetic acid.
minute, having a minimum intrinsic stroke length of 255 mm
NOTE 3—When a referee test is made the medium should be freshly
(10 in.), counter for recording the number of scrub cycles, base
prepared, or from a previously unopened container that is no more than
pan, glass support plate, “Lilly” frame, and C-clamps to hold
1-year old.
down the entire test assembly.
5.9 Analytical Balance With Windshield Enclosure, reading
5.2 Sponge Holder, stainless steel construction, weight: 450
to 0.1 mg and accurate to 1 mg.
610g,approximateinsidedimensions:22by75by95mm( ⁄8
5.10 Static Shield, a thin gage metal plate, size 110 by 165
by3by3 ⁄4 in.).
1 1
mm (4 ⁄4 by 6 ⁄2 in.), to be placed on the balance pan when
5.3 Polyurethane Sponges, skin free, open-cell formation,
weighing. A satisfactory shield can be made from 0.175 to
3 3
density 0.032 to 0.040 g/cm (2 to 2.5 lb/ft ), compression
0.300 mm (7 to 12 mil) thick aluminum or tinplate.
(25 %deflection)4.8kPa(0.7psi),widthandlength0.08in.(2
5.11 Oven, adjusted to 50 to 55°C (120 to 130°F).
mm) larger than the sponge holder with which it is to be used,
thickness such that when inserted into the sponge holder it
5.12 Calibration Panels, prepared in advance using paints
protrudes about 5 to 6 mm (0.25 in.) beyond the skirt (see Fig.
of suitable scrub resistance.
1).
NOTE 4—The procedure for preparing calibration panels is the same as
5.4 Abrasive Pad, 6-mm ( ⁄4-in.) thick, cut to same size as
described in 6.1 and 6.2 for regular test panels, except that the panels shall
beagedsufficientlybeforeusetoensurethattheeffectofadditionalageing
the sponge with which it is to be used.
on their scrub resistance is negligible. A period of 6 months has been
5.5 Film Caster, with horseshoe frame, clearance 175 µm (7
found adequate. Earlier use requires that in a given test series all
mils), film width approximately 135 mm (5 ⁄4 in.).
calibration panels be the same age.
5.6 Black Plastic Panels, dimensions: 0.25 6 10 % by 165
5.13 Pycnometer, for example, “weight-per-gallon” cup.
by 430 mm (0.01 6 10 % by 6.5 by 17 in.). Level and uniform
dull black surface, impervious to and unaffected by water or
aliphatic solvents, plasticizer-free, density 1.33 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.
NOTE 2—With dark colored paints use white panels. These should be
Hydroxyethyl cellulose having a molar substitution (MS) value from 1.8 to 2.5
the same as the black except for color, and density: 1.41 6 0.05 g/cm .
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.
4 10
Sponges, available from suppliers of scrub testers, cut to precise size for their 1,3,5-triethyl hexahydro-sym-triazine (Vancide TH), obtainable from R. T.
respective holders. Vanderbilt Co., 30 Winfield St., Norwalk, CT 06855, has been found satisfactory.
5 11
Abrasive pad—Scotch-Brite #7448 manufactured by 3M Company, 3M Center Calibration panels may be prepared by individual laboratories for internal use
Bldg., St. Paul, MN 55144-1000 has been found satisfactory. Pads cut to the correct and for relating their results to those of associated laboratories. Suitably aged and
size are available from suppliers of scrub testers. standardized calibration panels, having “poor,” “good,” and “very good” scrub
Scrub Test Panels—Black: Form P121-10N and White: Form P122-10N, resistance are available commercially from the Leneta Company. These are
available from The Leneta Co., 15 Whitney Rd., Mahwah, NJ 07430, were used in identified asTypeA, C, and D respectively.The scrub resistance ofTypeAhas been
the round-robin for this method. Other charts that are in compliance with foundtobeapproximately35 %ofTypeC,andTypeCapproximately50 %ofType
requirements stated in 5.6 may be used also. D.
D4213 − 08 (2012)
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
FIG. 2 Abrasion Boat Components
in the film. Air dry for one week in a horizontal position, in a
well ventilated area kept at 23 6 2°C (73 6 3.5°F) and 50 6
6.11 Distribute an additional 15 mL of scrub medium along
10 % relative humidity.
the scrub path then start the machine. (No additional scrub
6.3 At the end of the specified drying time cut the panel
medium is required during the test).
accurately in half with a paper cutter across the short
6.12 Scrub until either one of the two center sections has
dimension, and set aside one of the half-sections for a second
been worn down sufficiently for the black substrate to become
test. Take the other half-section and make two subsections by
faintlyvisiblewithoutactualbreak-through.Inanycase,donot
cutting again, parallel to and 75 mm (3 in.) from the previous
exceed800cycles.Duringthefirst200cycles(ifbothfilmslast
cut.
that long) reverse the direction of the pad every 50 cycles, and
6.4 Weigh the narrower subsection in grams to four decimal
above200cycles,reverseafterevery100,sothatthepadisrun
places.Itisessentialwhileweighing,forthestaticshieldtorest
about the same number of cycles in each direction. Record the
on the weighing pan and the panel to rest fully and flatly on the
number of scrub cycles at the stopping point.
static shield.
NOTE 7—If the scrub medium obscures the abrasion path, making it
NOTE 5—Weighing to four places is needed to ensure accuracy in the
difficult to observe the show-thru status of the film, stop the machine at
third (viz., to the nearest mg).
convenient intervals and sweep the surface briefly with a 50-mm (2-in.)
paint brush dampened with water.
6.5 Place the two subsections in the machine, on the glass
supportplate,withthefirst-cutedgeacrosstheexactcenterline
6.13 Remove and wash off the two center (narrow) subsec-
of the scrub path, and the wider subsection positioned so that
tions with tap water. Press them between paper towels to
the two second-cut edges are adjacent.
absorb free moisture, then oven-dry for 15 min at 50 to 55°C
(120 to 130°F). After drying reweigh the two subsections to
6.6 Repeat procedures 6.3, 6.4 and 6.5 using the selected
determine their weight losses, recording them as M and M
calibration panel (see Note 6), placing the first-cut edge of the
test n
in grams to four decimal places (“n” indicates identifying letter
calibration panel adjacent to that of the test panel. See Fig. 1
of the calibration panel type being used in the particular test,
for the configuration of the panel subsections on the support
for example M , M , M , etc.).
plate at this point.
A C D
6.14 Starting with 6.3, repeat the subsequent steps with the
NOTE 6—Use a calibration panel type similar in scrub resistance to that
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 scrubb
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