1、Designation: D 7377 09Standard Practice forEvaluating the Water Wash-Off Resistance of Traffic Paintsusing a Water Faucet1This standard is issued under the fixed designation D 7377; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, t
2、he year of last revision. 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 Atraffic paint film freshly applied to a roadway, air strip,or parking lot may be exposed to rain of varyin
3、g intensitiesshortly after application. This practice was designed to deter-mine the relative water wash-off resistance of an applied trafficpaint film under controlled laboratory conditions using a waterfaucet to simulate a heavy rain. This laboratory practice canalso be used to compare conventiona
4、l and fast-dry waterbornetraffic paints and the effects of binders and other components intraffic for their relative ability to withstand a heavy rain soonafter application.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.
5、3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Doc
6、uments2.1 ASTM Standards:2D 562 Test Method for Consistency of Paints MeasuringKrebs Unit (KU) Viscosity Using a Stormer-Type Viscom-eterD711 Test Method for No-Pick-Up Time of Traffic PaintD 823 Practices for Producing Films of Uniform Thicknessof Paint, Varnish, and Related Products on Test Panels
7、D 1005 Test Method for Measurement of Dry-Film Thick-ness of Organic Coatings Using MicrometersD 1212 Test Methods for Measurement of Wet Film Thick-ness of Organic CoatingsD 4414 Practice for Measurement of Wet Film Thickness byNotch Gages3. Terminology3.1 Definitions:3.1.1 conventional waterborne
8、traffc paint, nan aqueoustraffic paint that uses a conventional (non-fast-dry) latexbinder.3.1.1.1 DiscussionTypical no-pick-up dry times for con-ventional traffic paints by Test Method D711are 20 to 45 min.These paints are often used for zone marking of parking lotsand garages.3.1.2 durable fast-dr
9、y waterborne traffc paint, nan aque-ous traffic paint that uses a durable fast-dry latex binder.3.1.2.1 DiscussionAir or airless spray application onroadways is typically 0.65 mm (25 mils) wet or about 0.41 mm(16 mils) dry. The range of application for durable waterbornepaints is 0.56 to 0.89 mm (22
10、 to 35 mils) wet, but sometimesdurable paints are striped at standard line thickness. Typicalno-pick-up dry times by Test Method D711for durable paintsapplied at standard line thickness are 5 to 8 min.3.1.3 effective water wash-off dry time, nthe traffic paintdry time required for no visible loss of
11、 coating when conduct-ing the water wash-off Standard Practice.3.1.4 fast-dry waterborne traffc paint, nan aqueous trafficpaint that uses a fast-dry traffic latex binder.3.1.4.1 DiscussionThese paints are sometimes also re-ferred to as fast-hardening since they still may contain asubstantial amount
12、of moisture even though they feel dry.Typical no-pick-up dry times by Test Method D711 forfast-dry traffic paints are 10 min.3.1.5 standard line fast-dry waterborne traffc paint, nanaqueous traffic paint that uses a standard fast-dry latex binder.3.1.5.1 DiscussionAir or airless spray application on
13、roadways is typically 0.38 mm (15 mils) wet or about .223 mm(9 mils) dry. Typical no-pick-up dry times for standard linetraffic paints by Test Method D711are 5 to 8 min.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applications and is the
14、 direct responsibility ofSubcommittee D01.44 on Traffic Coatings.Current edition approved June 1, 2009. Published July 2009. Originally approvedin 2007. Last previous edition approved in 2008 as D 7377 - 08.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer
15、 Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.6 waterborne traffc paint, nan aque
16、ous traffic paint(usually white or yellow) containing either a conventional orfast-dry latex binder.3.1.7 water wash-off resistance, nthe resistance of a trafficpaint line to partial or complete wash-out during a rain.4. Summary of Practice4.1 This standard practice involves preparing a series ofuni
17、form thickness films of traffic paint on standard substrates.The films are allowed to dry over different time periods, andthen each paint film is subsequently tested with the water-wash-off test to determine the relative amount of coatingremaining at the end of the wash off period.5. Significance an
18、d Use5.1 After waterborne traffic paints are applied to a road,airstrip, or parking lot pavement, it is important that the paintfilms be sufficiently hardened, coalesced, or cured so they willnot be removed by rain. This practice can be used to determinethe relative performance of binders and other
19、componentswithin traffic paint for their effect on the water-wash offresistance of the coating. Some key elements of the coating thatmay affect water-wash-off performance are the quality and typeof latex binder, the dry time of the coating (often conducted byTest Method D711), pigment volume concent
20、ration (PVC),and the relative water sensitivity of additives (for example,pigment dispersants, and surfactants) in the coating.6. Apparatus and Equipment6.1 Paddle Type Viscometer, to measure viscosity (in Krebsunits) of the traffic paint prior to application.6.2 Conditioning Room, to provide a cons
21、tant standardenvironment of 23 6 2C (73.5 6 3.5F) and 50 6 5%relative humidity during film draw-downs and film drying.6.3 Conditioning Chamber, convenient to provide a con-stant standard high humidity environment of 23 6 2C (73.5 63.5F) and 90 6 3 % relative humidity during film draw-downsand film d
22、rying.6.4 Graduated Cylinder, to determine and adjust water flowrate from faucet.6.5 Humidity Gauge, to record relative humidity during thedrying period.6.6 Thermometers, to record the air and water temperatures.6.7 Spatula, to mix the paint prior to application.6.8 Glass Plates, for film draw-downs
23、 (see also option forcharts in 6.9).6.9 Draw-Down Chart, preferred option for film draw-downs. Black Scrub Test Panels are preferred and can be cut inhalf to give two test panels of 16.5 by 21.6 cm (612 by 812 in.)size. Use of these charts instead of a glass plate allows for apermanent record of the
24、 test results.6.10 Film Applicator (15 cm (6 in.) width, to obtain 0.38mm (15 mil) wet thickness for standard traffic paints or 0.64mm (25 mil) wet thickness for durable traffic paints.6.11 Wet Film Gauge, to measure wet film thickness.6.12 Sink with combined hot and cold tap water faucet,toapply wa
25、ter stream onto test panel film during the waterwash-off testing.6.13 Lab Jack, to support the applied paint film, and tocontrol distance from the water nozzle.6.14 Timer, to time the film-drying and the water wash-offperiods.6.15 Camera, to record the image of the panel after comple-tion of the tes
26、t.7. Reagents7.1 Tap Water (Cold)applied to the film preferably with astandard nozzle, at controlled flow rate, controlled watertemperature, and constant distance from the test paint films.7.2 Acetoneto clean glass plates prior to application (notneeded for draw-down charts since they are not reused
27、).8. Procedure8.1 Paint Consistency:8.1.1 Determine the Krebs (KU) viscosity of the paint inaccordance with Test Method D 562 using a paddle-typeviscometer as prescribed by Test Method D 562. This determi-nation is optional but can be important since the dry time of thetraffic paint and water wash-o
28、ff performance can be affected bythe paint viscosity.8.2 Application of Paint Films:8.2.1 For most consistent results and for testing undercontrolled conditions, it is recommended that paint film draw-downs be applied and allowed to dry in a controlledtemperature/controlled humidity (CTCH) room and/
29、or in asmall conditioning chamber. The conditioning chamber isconvenient for high humidity testing. Standard conditions areshown in 6.2 and 6.3 respectively. Select the appropriatedraw-down bar to obtain the desired film thickness. A 0.38 mm(15 mil) wet film thickness is typical for standard-line tr
30、afficpaints, and a 0.64 mm (25 mil) wet film thickness is typical fordurable traffic paints. The film thickness determination shouldbe made in advance using Practice D 823 by making a series ofdraw-downs with different applicator gaps and measuring thewet-film thickness of each using Test Method D 1
31、212 or TestMethod D 4414. The actual wet film thickness is often muchlower than the indicated film applicator gap, for example, a 25mil gap may produce a 15 mil wet film thickness. Dry filmthickness can optionally be determined using Test MethodD 1005. Clean a series of four glass plates with aceton
32、e, oroptionally use the preferred black draw-down charts for thefilm draw-downs.Allow the glass plates or charts to equilibrateto room temperature. Place about 10 ml of paint on the topcenter of the glass plate or draw-down chart and drag thedraw-down bar over the paint to produce a coating of unifo
33、rmthickness. Immediately start a timer for each film drawn-down,and allow the films to dry undisturbed for the designated timeperiod. Let one film dry for exactly 15 min., one for 30 min.,one for 45 min., and one for 60 min. At the end of each drytime period, the water wash-off test is conducted on
34、the paintfilm (see 8.3).8.3 Running Water Wash-Off Test:8.3.1 Select a sink deep enough for the wash-off test with aminimum of 40 cm (16 in.) distance from the faucet nozzle tobottom of sink. Place a lab jack in the sink and adjust the heightfrom the platform to the water faucet nozzle to keep thedi
35、stance constant. A distance of 30.5 cm (12 in.) is standard.D7377092This adjustment is important particularly if different sinks areused for the test. The drain should remain unobstructed so thatthe sink does not fill with water during the test. Turn both thecold and hot water faucets on, and adjust
36、 the flow rate andwater temperature to 5.7 L/min (1.5 gal/min) and 25Crespectively. The flow rate can be determined using a graduatedcylinder to measure the volume over a fixed period of time. Thestandard nozzle opening is 1.0 cm (0.40 in.). Any deviationfrom nozzle size, flow rate, or water tempera
37、ture will givedifferent results and should be recorded if not standard. A flowregulator to control the water pressure may be helpful toprovide the correct predetermined flow rate.8.3.2 When the dry time is expired for a paint test film andwith the water flow/temperature already adjusted, place thegl
38、ass panel or draw-down chart on the lab jack. Move thefaucet over the panel with the flow impinging on the center ofthe paint film and immediately start the timer. Watch the paintfilm and record the time it takes for the water to break throughthe film. Allow the film to remain under the flow of wate
39、r fora full 5 min. and then remove it. Note any blistering orsoftening of the remaining paint film. At the appropriate times,test the remaining film panels in similar fashion. A camera canbe used to obtain a picture for a comparative record of the testresults. The black chart substrates are particul
40、arly good forcontrast of the area washed off (black substrate will showthrough) with the remaining white or yellow paint films. Ifglass panels are used, they can be placed on a black substratefor similar contrast. For clean-up of glass plates, run the platesunder hot water to loosen the film and the
41、n scrape the paint offwith a razor blade scraper. The draw-down charts can simplybe discarded or retained for visual record.8.4 Relative Running Water Wash-Off Performance for aTest Series, see Fig. 1.9. Report9.1 The following ideally should be recorded when usingthis practice:9.1.1 Viscosity of th
42、e paint in Krebs Units (KU),9.1.2 Drying conditions (temperature and humidity), wetfilm thickness, and dry times for each draw-down,9.1.3 Water temperature, distance to panel, and water flowrate, and9.1.4 Relative water wash-off performance comparisons fora given set of panels, that is, panels can b
43、e ranked from best toworst or pictures can be taken as a relative performance record,or both.10. Keywords10.1 rain resistance; traffic paint; water resistance; waterwash-off; water wash-outFIG. 1 Illustrative Example of Water Wash-Off Performance for a Traffic Paint Test SeriesD7377093ASTM Internati
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45、r own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should b
46、e addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standard
47、s, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D7377094
