CA2217609A1 - Method for cleaning environmental soils from outdoor unfinished surface - Google Patents

Abstract

A method of diluting concentrated cleaning composition and cleaning outdoor soiled surfaces with the diluted cleaning composition. The concentrated cleaning solution can include an aqueous chlorinated bleach solution, a surfactant, a phosphate and a silicate. The concentrated cleaning solution is diluted with water to form a diluted composition which is applied to the surfaces to be cleaned to effect loosening of soil. Thereafter, the loosened soil is removed by the mechanical action of a water spray. The cleaning composition can be sprayed onto the surface to be cleaned by a hand held sprayer such as an air-gap or closed venturi type of hose end sprayer.

Description

~CA 02217609 1997-10-08 METHOD FOR CLEANING ENVIRONMENTAL SOILS
FROM OUTDOOR UN~ SURFACE

FIELD OF THE INVENTION
The present invention relates to a method for cleaning environmental soils such as mold, mildew, algae, grease, and stains from a variety of outdoor ~nfini.~hed surfaces such as raw wood, sealed wood, and ul-p~ e~l surfaces of stone, masonry, brick, stucco, etc.
BACKGROUND OF THE INVENTION
Current methods for the cleaning of homes vary from scrubbing with common household deLergents to professional pressure cleaning. Although effective, the scrubbing procedures are very labor intensive due to the large surface area involved and can require the use of ladders as well as climbing on top of roofs for two stor~v homes. Professional cleaning is inconvenient and costly.
There are products culleuLly on the market which are considered scrub-free but are based on a special high pressure hose fitted nozzle which produces a very narrow blast of water with siphoned detergents. Most of the soil removing is accomplished due to the force of the water impacting against the soil. This type of system is very time consuming due to the narrow water blast and large surface area involved. It can be ineffective in removing some biological soils such as algae and mold.
Another non-scrub cleaner on the market applies chlorine bleach to the surface in high concentration from a pump-up sprayer. The action of the chlorine attacks and dissolves the biological soils followed by a rinse. Virtually all of the soil removal is accomplished from the cleaner and the rinse plays a minor role. Again the operation is time consuming due to the length of time it takes to apply the cleaner from a pump up sprayer and use of ladders and roof climbing is often required to reach all of the surface.
Numerous cleaning products are ~;ullcu~ly known for cleaning different types of surfaces such as wood, plastic and metal, which are exposed to the outdoor S environment. These materials are used in making decks, fencing, siding and so forth, and each presents unique problems with respect to cleaning. The known products usually require some type of scrubbing or brushing in order to achieve the stated purpose. Further, many of these products require mixing or measuring of some sort and therefore are very susceptible to being mixed improperly thus rendering them ineffective or an environmental and safety hazard. Many of the products also harm plants, fish, animals, or birds, and such products can destroy the landscaping and/or wildlife around the structure being cleaned.
The need for universal, or at least multiple surface compatibility is most relevant in applications where a surface to be cleaned comprises but a part of an overall structure, and where constraints of time and effort discourage a carefulconfining of the cleaning solution exclusively to the soiled surface.
An example of this is the cleaning of outdoor painted or stained surfaces on a house. Typically such surfaces are interrupted by window and door frames comprised of aluminum, steel and/or wood. The cleaning solution should function effectively on each surface to be cleaned without harm to such surrounding othermaterials. This would enable a blanket application of the solution over a large area in a short amount of time. It would also be desirable to apply via spraying a cleaning solution using a garden hose rather than a pump-up sprayer. Also, the cleaning solution should remove soil without brushing or scrubbing. This is highly desirable, again, on the upper portions of a house.
As a cleaning solution, chlorine bleach is known to remove mold, mildew and other organic and inorganic soil from outdoor surfaces. However, chlorine bleach, st~n(ling alone, corrodes metal and hence would be un~uit~hle in blanket applications such as outdoor surfaces on houses with metal window and door frames. Bleach without a surfactant can spread unevenly and stain wood surfaces.

Various cleaning compositions which incorporate an aqueous bleach component are disclosed in U.S. Patent Nos. 4,057,505; 4,071,463; 4,113,645;
4,116,851; 4,789,495; and 4,806,263. The '505 patent incorporates a synthetic alcohol sulfate surface active agent and 0.05 to 2% (as used herein, % refers to wt.
% unless otherwise indicated) alkali stabilizer such as sodium hydroxide, sodiumcarbonate or sodium orthophosphate in an aqueous solution of 3 to 7% alkali metal hypochlorite for laundry cleaning purposes. The '463 patent acknowledges the problem of lack of stability when ingredients are combined with hypochlorite bleaches. In addition, the '463 patent incorporates an alkali metal alkyl sulfate, an alkylated diphenyl oxide sulfonic acid alkali metal salt such as sodium dodecyl diphenyl oxide disulfonate ("DOWFAX 2Al"), a branched chain alkyl aryl sulfonateor mixtures thereof in an aqueous solution of 0.25 to 1.0% sodium hypochlorite with an ~lk~line builder such as sodium carbonate, trisodium phosphate, sodium metasilicate or sodium hydroxide to m~int:~in the pH above 11Ø The '645 patentdiscloses a perfumed 1 to 15% hypochlorite bleach composition which is stable over long periods of time by lltili7ing perfume oils resistant to the oxidative effects of the bleach. The '851 patent incorporates up to 15% of a builder, up to 10% of a surfactant, 0.25 to 20% of a thickening agent and 0.5 to 9% of an alkali metal silicate such as sodium silicate in a 1 to 10% aqueous solution of sodium hypochlorite used for cleaning kitchen utensils. The '495 patent discloses a cleaner for tiles, porcelain, floors, drains and laundry which incorporates 0.1 to 3 % of a tertiary alcohol, a 0.5 to 7% of a hypochlorite-compatible surfactant, and up to 10% of an alkali metal hydroxide, an optional sodium silicate corrosion inhibiter in an aqueous solution of 0.5 to 10% sodium hypochlorite having a pH above 10 and shelf stability of at least three months. The '263 patent discloses a cleaner for solid surfaces which can be applied by a sprayer and which incorporates 0.003 to 0.4% of a water insoluble fungicide, algicide or mixture thereof, 1.0 to 6.0% de~ergellt, 3 to 10% of a pH adjuster such as boric acid to adjust the pH to 4.0 to 8.5 prior to addition of an oxidizing agent, a thickener, and up to 1.0% of a chelating/sequestering agent such as sodium tripolyphosphate or trisodium phosphate in an aqueous solution of 5.25%
sodium hypochlorite.
Although the foregoing patents disclose aqueous solutions of sodium hypochlorite for various cleaning purposes, these patents do not specifically address the need for a cleaner which removes foreign matter such as mold, mildew, algae,grime, pollen, pollution, etc., which build up on outdoor un~lni~hed surfaces.
Moreover, these patents do not address the need for a cleaner which is biodegradable and which does not attack exposed glass and metal surfaces on such buildings.
There is hence a need in the art for a cleaning solution which functions effectively in cle~ning llnfini~hed surfaces such as wood, brick, concrete, etc., and which can be used effectively in blanket applications without worry of damage toadjacent metal or wood and glass surfaces. There is also a need in the art for acleaning solution which is effective without the need for brushing and scrubbing to remove soll.
SUMMARY OF THE INVENTION
The invention provides a method for cleaning environmental soils such as mold, mildew, algae, and/or dirt from unfini.~hed outdoor surfaces, such as raw wood, sealed wood, unpainted stone, unpainted masonry, nnr~inteA brick, unpainted stucco and the like, the method comprising the steps of forming a diluted cleaning composition by feeding a concentrated aqueous cleaning composition cont~ining bleach and water into a mixing chamber of a spray gun; spraying the diluted cleaning composition from the spray gun onto the outdoor nnfini~hed surface to be cleaned;
allowing the diluted cleaning composition to remain on the surface to be cleaned for a period of time sufficient to loosen material to be removed from the surface to be cleaned; and optionally removing the loosened material and diluted cleaning composition from the surface to be cleaned by spraying rinsing water onto the surface to be cleaned. The concentrated cleaning composition is preferably a solution in a container attached to the spray gun and the water is supplied by a water hose attached to the spray gun.

According to a L,l~relred embodiment of the method, the water is fed into the mixing chamber through a first inlet in the spray gun, the concentrated cleaningcomposition is fed into the mixing chamber through a second inlet in the spray gun and the diluted cleaning composition and/or the rinsing water are sprayed from the spray gun through at least one outlet in the spray gun. The spray gun can include first and second outlets to allow the diluted cleaning composition to be sprayed only from the first outlet and the rinsing water to be sprayed only from the second outlet.
The spray gun can be an aspirator type spray gun such as an air-gap or a closed venturi type spray gun.
Water is mixed with the concentrated cleaning composition to dilute the concentrated cleaning composition by amounts such as 1:0.5 to 1:200, preferably about 1:1 to 1:50 and more preferably about 1:1 to 1:10 parts concentrated cleaning solution to water during the step of forming the diluted cleaning composition. The diluted cleaning composition can be sprayed from the spray gun at a first flow rate and the rinsing water can be sprayed from the spray gun at a second flow rate, the second flow rate being less than, equal to or greater than the fIrst flow rate. The diluted cleaning composition can be sprayed from the spray gun in a first paKern and the rinsing water can be sprayed from the spray gun in a second pattern, the second pattern being smaller and at a higher velocity than the first pattern. The velocity of the water in the rinsing step can be from about five meters per second to about 30 meters per second and the volume of water applied to the surface in the rinsing step can be from about 1 to about 10 liters per square meter of surface.

BRIEF DESCRIPIION OF THE DRAWINGS
FIG. 1 shows a venturi-type sprayer useful for carrying out the method of the invention in a partially exploded and cross-sectional view;
FIG. 2 shows a cross-sectional view of a housing of the sprayer shown in FIG. l;
FIGS. 3a-c show details of the cover shown in FIG. 1, wherein FIG. 3a shows a lon~ (lin~l cross-sectional view of the cover, FIG. 3b shows a transverse cross-sectional view taken along the line A-A in FIG. 3a and FIG. 3c shows a topview of the cover shown in FIG. 3a;
FIG. 4 shows details of the multi-position valve shown in FIG. l;
FIGS. 5a-d show details of an antisiphoning device shown in FIG. 1 wherein FIG. Sa is an axial end view of a cylindrical member, FIG. Sb is a cross-sectional side view of the cylindrical member of FIG. Sa, FIG. Sc is a perspective side view of the cylindrical member shown in FIGS. Sa-b and FIG. 5d is a side view of a conical member which together with the cylindrical member forms the antisiphoning device;
FIGS. 6a-b show details of the housing of the sprayer shown in FIG. 1, FIG. 6a showing an axial end view in partial cross-section of the housing and FIG. 6b showing a top view of the housing;
FIGS. 7a-c show details of an embodiment of the housing of the sprayer shown in FIG. 1, FIG. 7a showing a top view in cross-section of a snap-on spray pattern member, FIG. 7b showing a side view in cross-section of the member shownin FIG. 7a, and FIG. 7c showing a front view of the member shown in FIG. 7a;
FIGS. 8a-b show details of an embodiment of the orifice plate shown in FIG.
l;
FIGS. 9a-e show details of a modification of the sprayer in FIG. l;
FIG. 10 shows an air-gap sprayer useful for carrying out the method of the invention; and FIGS. lla-f show details of deflectors which can be incorporated in the sprayers shown in FIGS. 1 and 10.

DETAILED DESCRIPIION OF l~IE PREFERRED EMBODIMENTS
One object of the invention is to provide a method of cleaning environmental soils from outdoor lmfini~hed surfaces such as masonry, stucco, concrete, brick,etc., or raw or sealed wood without damage to the surrounding environment. For instance, the method preferably utilizes a cleaning composition which does not aKack and/or corrode surrounding metal and/or glass surfaces and can be rinsed from the soiled outdoor surfaces without harm to a-lj?cPnt plant and/or animal life.
The cleaning composition used in the method according to the invention preferably is an aqueous chlorinated bleach solution which may contain a surfactant in an amount effective for weKing of the surface, penetration into the soil and minimi7e destabilization of the available chlorine in the bleach solution. The cleaning composition can also contain a phosphate in an amount effective for stabilizing the available chlorine in the bleach solution by m~int~ining the pH of the bleach solution at a level which retards oxidation of the available chlorine.
Moreover, a silicate can be incorporated in the cleaning composition in an amount effective for protecting metal and/or glass surfaces which come into contact with the bleach solution by forming a molecular film on the metal and glass surfaces.
The silicate and phosphate are preferably added together since the phosphate reduces the adverse effects of hard water on the silicate and-the surfactant. Further, since bleach degrades over time and produces acid thus lowering the pH of the cleaning composition and the bleach degrades very rapidly when the pH of the cleaning composition lowers to about 10, a phosphate can be added to the cleaning solution for purposes of taking up acids and thus prolonging the life of the bleach solution.
The cleaning composition can include a cationic, anionic or non-ionic surfactant to help spread the cleaning composition over the surface or surfaces to be cleaned. For instance, the surfactant can comprise a sulfonated surfactant such as "DOWFAX 2Al" (sodium dodecyl diphenyloxide disulfonate) sold by DOW
Chemical Co. The surfactant acts as a weKing agent which aids water in spreading over the surface to be cleaned and/or penetration of the blearhing agent through soil to be removed from the surface to be cleaned.
The cleaning composition can include an anti-corrosive agent such as a silicate to protect metal surfaces such as alllmimlm. The silicate can be present in an amount sufficient to protect metal surfaces but below an amount which can attack (e.g., etch) the metal or surrounding glass surfaces and/or form a deposit on such surfaces which is difficult to remove. In situations where the cleaning solution is mixed with hard water, it is advantageous to also include a phosphate water softening agent such as TSP (trisodium phosphate) and/or STPP (sodium tripolyphosphate). Otherwise, the sodium metasilicate would react with the hard water and the effectiveness of thesodium metasilicate in protecting the metal surfaces would be lowered.
The silicate provides protection of glass and/or al~ ll surfaces which come into contact with the cleaning composition. An especially plerellcd silicate is an alkali silicate such as sodium silicate (NatO SiO2) since sodium silicate forms a protective molecular film on ~luminllm surfaces. For example, a useful sodium silicate is sodium metasilicate or "SILICATE D" made by the PQ Corporation located in Valley Forge, PA. On the other hand, calcium silicate is not effective in protecting alnminllm surfaces. The Na:Si ratio preferably ranges from 1:1 to 1:4since such ratios are effective in providing a molecular SiO film on all-minllm The content of the silicate in the cleaning solution preferably provides the protective SiO
film but avoids staining of metal and glass surfaces. Surprisingly, as little as 0.1%
sodium silicate in the concentrated cleaning composition has been found to provide adequate film forming properties.
The cleaning composition can be in the form of a concentrated bleach cont~ining solution and a hand-held portable spray gun attached directly or indirectly to a container of the concentrated cleaning composition can be used to dilute and apply the cleaning composition to a surface to be cleaned. For instance, the container can be conn~ctecl to the spray gun by tubing or the container can be held on the spray gun. The cleaning composition can be any bleach cont~ining solution such as of the type disclosed in commonly-owned U.S. Patent No. 5,376,296, the disclosure of which is hereby incorporated by reference which discloses bleach compositions including 0.1 to 10% surfactant, 0.1 to 8% alcohol and the balance a 1-4% aqueous chlorinated bleach solution. However, bleach solutions with or without alcohol or additional ingredients such as fragrances, sealants, biocides, tinting agents, silicone, wax, etc., can be used to clean the llnfini~hed surfaces.
The spray gun can include an inlet port attached to a garden hose for supplying pressurized water and at least one outlet port for spraying the diluted cleaned composition onto the surface to be cleaned or spraying only water to rinse the surface to be cleaned. The diluted cleaning composition can be sprayed onto an outside surface, allowed to remain on the surface for a period of time (e.g., 10miml~los) sufficient to loosen and/or bleach the soil to be removed and subsequently the loosened soil can be mechanically blasted from the surface due to the force of the water spray impacting against the loosened soil. Thus, a very weak cleaning solution can be used which is not detrimental to the surrounding environment. However, depending on the porosity of the surface to be cleaned, its orientation (e.g., vertical, horizontal, etc.) and the strength/effectiveness of the cleaning composition, the relative concentration of the ingredients in the concentrated and diluted forms can be adjusted accordingly.
In order to provide the greatest ease of application of the cleaning compositionand/or rinsing of the surface to be cleaned, the spray gun can be designed to spray a pattern of diluted cleaning composition or jet of only water a distance sufficient to reach the outdoor surface to be cleaned, e.g., the spray may be projected a distance sufficient to reach at least a first floor and even up to a second story of a house or building to be cleaned. Such distances will be achievable if the water pressure is sufficient. However, for other applications such as cleaning outdoor wooden decks, patios, driveways, etc., the spray gun can be designed to provide a spray pattern which is delivered a short distance.
The invention overcomes the ineffectiveness and/or inefficiencies of the practices and products cu.lelltly on the market. Specifically, the invention is a do-it-yourself cleaning system that combines the effectiveness of chlorine bleach with the efficiency of a hose-end sprayer. This results in a non-scrub cleaning system where the soil removal comes from a combination of chemical attack of the chlorine on the soil which weakens its bond to the soiled surface followed by an optional rinse with enough force to remove the weakened soil.
The effectiveness and efficiency of the inventive wash system for the removal of difficult soils comes from the contribution of both the diluted cleaner and the force of rinse in such a way that 1) an exceptionally strong concentrate is not needed so that the efflciency of a hose-end sprayer can be used which by its nature dilutes and thereby weakens the cleaner and 2) an exceptionally strong rinse force is not needed so that the pressures usually available to the consumer will provide an adequate force against the preweakened soil in order to remove it. This system is intended to be safe for plants, ~nim~ and non-corrosive to the skin or eyes. However, the removal of the environmental soils from the lmfini~hed surfaces can be achieved without rinsing, e.g., t_e system can be used with no-rinse cleaners or the consumer can rely on rain water to remove the loosened soils.
The sprayer can be designed to spray short distances or reach up to 20 feet high which is necessary for two-story homes thereby minimi~ing the need for ladders and unsafe climbing onto roofs. Further, chlorine stability to the liquid cleaner formula is desired so that the performance of the product is m~int~ined for a length of time (e.g., at least three months) beyond that which the product would normally be used after purchase by the consumer. The cleaning composition can be formulated so as not to damage other building materials which may be in the immediate vicinity of the soiled surface such as glass, al--minl-m and galvanized steel.
Various surfactants can be used in the cleaning composition such as anionic, cationic and non-ionic surfactants. For instance, surfactants suitable for the concentrated cleaning solution based on compatibility with chlorine and wetting power include:

Mono and Dialkyl diphenyl oxide disulfonates- Typical examples are the DOWFAX Surf~t~nt.~, a trade name of the Dow Chemir~l Co.

.

Sodium Lauryl Sulfate- A typical example is STEPANOL WAC, a trade name of the Stepan Co.
Sodium Dodecylbenzenesulfonate- A typical example is the neutralized form of BIOSOFT S-100, a trade name of the Stepan Co.

If desired, various builders can be included in the cleaning composition. For instance, the builders can include carbonates and water soluble phosphates such as alkali metal carbonates, alkali metal phosphates, STP, TSP, pyrophosphates, hexametaphosphates, orthophosphates, and tripolyphosphates. Two phosphates whichhave been successfully used for this application are sodium tripolyphosphate andtrisodium phosphate. While both work well to counter the water hardness effect, trisodium phosphate was found to have an advantage over the tripolyphosphate in its alkaline buffering character. This buffering effect which absorbs acids produced by the degradation products produced by the attack of chlorine on the surfactant and any other organics in the formula, slows the rate of pH reduction and thus slows the rate of Cl loss. For instance, the pH of the hypochlorite solution drops as the Cl level decreases and the rate of Cl loss increases rapidly when the pH falls below 10.
Other ingredients which can be included in the cleaning solution include anticorrosive agents such as silicates, disinfectants such as EPA registered bleach, etc., oxidizing agents such as bleach, sodium perborate, peroxygen acid, peroxy compounds, etc., and other desired ingredients.
Preferred Formulations of the concentrated cleaning composition are as follows:

Ingredients (in weight %) A B C D E F
5.25 % Sodium Hypochlorite 96.7596.75 96.55 96.75 96.75 96.55 Solution Trisodium phosphate (TSP) 1.00 - 1.00 Sodium Metasilicate 0.25 0.25 0.25 0.25 0.25 0.25 Pentahydrate Ingredients (in weight %) A B C D E F
Sodium Lauryl Sulfate 2.00 2.00 2.00 (STS) Sodium Tripolyphosphate 1.00 1.00 - 1.00 1.00 (STPP) fragrance - - 0.20 - - 0.20 DOWFAX 2A1 2.00 2.00 2.00 The concentrated cleaning solution can be applied with a suitable spray gun such as a sprayer sold by Green Garden Inc., of Somerset, Pennsylvania. This type of sprayer is known as Green Garden's K-l Sprayer, Model No. 103-B. The sprayer has two roles: it is used to dilute and apply the concentrated cleaning solution to soiled outdoor surfaces and again to remove stains and soils loosened by the cleaner using forceful rinsing. The K-l accomplishes this with one exit hole that delivers one spray pattern.
The K-l sprayer is illustrated in FIG. 10 which shows a sprayer 200. This particular sprayer applies and removes the product using a 3- position selector 204 which has an "on" position 205, a "water only" position 206 and an "off" position 207. When attached to a garden hose 208, the sprayer can deliver a stream of diluted mixture of product, a stream of water for rinsing, or be completely turned off. In the "on" position, when dilution is occurring, a pick-up tube 209 serves as a basic siphon. This tube 209 is dipped into the product bottle 210 and the entire sprayer is fastened to the bottle. The siphon, known as an aspirator, is created when flowing water passes over a depression/hole 211 in the bottom of a mixing chamber 212 ofthe sprayer. A vacuum forms at the top of this hole opening which draws the product upward through the pick-up tube and into the passing water stream where it is diluted/mixed. The resulting product to water ratio delivered through exit hole 203 by the current model 103-B sprayer typically falls in the range of 1:17 to 1:25.

However, the optimum mixing ratio ultimately depends on the strength of the concentrated cleaning composition. -The volume of water being delivered by the K-1 sprayer pro~,-ides acceptable rinsing power and range of distance for delivery of diluted product/rinsing water.
However, a large volume of product may be drawn from the boKle while m~int~ininga 1:20 ratio resulting in that the boKle is emptied quickly. This water volume/product volume relationship is directly proportional (i.e., as water volume increases so must product volume) and serves to define the efficiency of the sprayer in terms of product usage and conservation. Accordingly, other sprayer arrangements which optimize rinsing power, spray distance and conserve product can be used.
Other sprayers can be used to apply a diluted cleaning solution onto soiled outdoor surfaces in accordance with the invention. For instance, the sprayer can be of the types disclosed in comrnonly-assigned U.S. Patent Application Serial Nos.08/651,952 and 08/511,142 (now U.S. Patent No. 5,595,345), the disclosures of which are hereby incorporated by reference.
The sprayer designs disclosed in commonly-assigned U.S. Patent No.
5,595,345 can provide improved consistency in water/product mixing ratios, range of delivery and/or different spray paKerns for a water-only rinse or water/product mixture. The sprayer can incorporate an air-gap or closed venturi system, an orifice plate delivery mechanism and/or a dual charnber exit for delivery of water-only from one exit hole and product from the other exit hole. The sprayer can also include a three-position valve for supplying water-only in a first position, a water/product mixture in a second position and preventing outflow of product or water in a third position. However, the water/product mixture and rinsing water can be sprayed from the sarne outlet or the sprayer can omit the rinsing function, in which case, a two way valve can be used for turning the sprayer on and off.
As shown in FIG. 1, sprayer 2 is ~ h~ble to a free end of a hose 4 such as a residential garden hose. The sprayer is also ~tt~h~hle to a container 6 of product such as a concentrated cleaning solution. The concentrated cleaning solution can be a cleaning solution suitable for cleaning vinyl siding such as the cleaning solution disclosed in commonly owned U.S. Patent No. 5,605,578, or the painted/artificially stained wood wash product disclosed in comrnonly owned U.S. Patent No. .
5,567,247, the disclosures of which are hereby incorporated by reference. The product is withdrawn from container 6 and mixed with a pressurized liquid such as water supplied by hose 4.
The sprayer 2 includes a first internally threaded fitting 8 for ~ rllment to a threaded end 10 of hose 4 and a second internally threaded rotatable fitting 12 for attachment to a threaded outlet of 14 of container 6. Alternatively, a rotatable fitting could be used for attaching the hose 4 to the sprayer. Further, other methods ofattaching hose 4 and container 6 could be substituted for the threaded fittings 8, 12, e.g., snap fittings, compression fittings, etc.
According to one embodiment, sprayer 2 includes a housing 20, cover 30 and valve member 40. As shown in FIG. 2, the housing 20 has a dual outlet arrangement wherein an upper outlet 21 is a water-only outlet and a lower outlet 22 is a diluted product outlet. Likewise, as shown in FIGS. 3a-c, the cover 30 has an upper water-only outlet 31 and a lower diluted product outlet 32. The upper outlet 31 is supplied water through upper passage 23 in housing 20 and the lower outlet 32 is supplieddiluted product through lower passage 24 in housing 20. With this arrangement, outlets 31, 32 can have different shapes and/or sizes to selectively provide desired spray patterns for the water-only and diluted product sprayed from the sprayer. For instance, by proper choice of the outlet size and/or shape, it is possible to apply the diluted product in a wide pattern and/or with moderate impact force on a surface to be coated with the diluted product. On the other hand, since the water-only rinse is applied through a different outlet, it is possible to apply the water-only rinse to the surface with a more narrow spray pattern and/or with greater impact force compared to the diluted product spray pattern.
With the dual outlet arrangement, it is desirable to utilize a multi-position valve member 40, as shown in FIG. 4, for selectively applying the water-only or diluted product to the respective outlets 31, 32. The valve member 40 is movable to first, second and third positions whereby outlets 31, 32 are prevented from spraying water-only or diluted product when valve member 40 is in the third position, outlet 32 is supplied diluted product and outlet 31 is prevented form spraying water-only when valve member 40 is in the second position and outlet 31 is supplied water-only S and outlet 32 is prevented from spraying diluted product when valve member 40 is in the first position.
As shown in FIG. 4, the valve member 40 includes a cylindrical body 41 having upper passage 42 and lower passage 43. In order to supply water from hose 4 to passages 42 and 43, housing 20 includes a cavity 26 which is in fluid communication with upper and lower passages 42, 43. Body 41 is rotatably mountedin bore 25 of housing 20 such that upper passage 42 supplies water to upper outlet 31 through upper passage 23 when valve member 40 is in the first position. By rotating valve member 40 to the second position, upper passage 42 is rotated out of fluidcolnlllu,lication with upper passage 23 and lower passage 43 in body 41 is aligned with lower passage 24 so that diluted product can be supplied to lower outlet 32. By rotating valve member 40 to the third position, upper passage 42 is out of fluidcommunication with upper passage 23 and lower passage 43 is out of fluid communication with lower passage 24. To prevent leakage, body 41 includes seal member 44 which sealingly engages inlets of passages 23, 24 and upper O-ring 45 and lower O-ring 46 prevent leakage between valve member 40 and housing 20.
In another embodiment, concentrated product in container 6 is supplied to lower passage 24 via an orifice plate arrangement 50 mounted in tubular projection 27 in housing 20. In particular, concentrated product is withdrawn from container 6 through tube Sl, passes through a plurality of holes 52a,52b in orifice plate 52, through passage 28 in housing 20 and into lower passage 24. As shown in FIG. 2, plate 52 tightly fits within an opening 29 defined by tubular projection 27 and a free end of tube Sl sealingly engages the opening 29 such that plate 52 is located between tube Sl and passage 28. The orifice plate arrangement provides more unifollll and consistent mixing of concentrated product with water within a desired range of water/product mixing ratios (e.g. 10 to 30 parts water to 1 part concentrated liquid product) over a wide range of water pressures (e.g., 40 to 60 psi) typically supplied by household exterior faucets.
Compared to air-gap sprayers which utilize an open air mixing chamber, sprayer 2 achieves mixing of concentrated product from container 6 and water from hose 4 in lower passage 24 by providing passage 24 with a small diameter upstream portion 24a and a large diameter downstream portion 24b. To enhance mixing, upstream portion 24a can have a non-circular cross-section and downstream portion 24b can have a circular cross-section. Passage 28 is in fluid communication withdownstream portion 24b and water passing under pressure through upstream passage24a drops in pressure in downstream passage 24b thus creating a partial vacuum in an area of passage 28 and drawing concentrated product up through tube 51 and into downstream passage 24b wherein the concentrated product is thoroughly mixed withthe water.
According to another embodiment, fitting 8 is integral with housing 20, e.g., fitting 8 and housing 20 can be injection molded from plastic in one piece, as shown in FIG. 2. In this case, the housing can be screwed onto the hose 4 prior to attaching the container 6. To allow easier ~ hment of container 6, housing 20 can include a tubular projection 60 which has an annular recess 61 on the outer periphery thereof. Fitting 12 snap fits over projection 60 by eng~ging recess 61 with a suitable mating annular flange (not shown) whereby end 14 of container 6 can be screwed into fitting 12 by rotating fitting 12. If desired, another rotatable fitting arrangement as used to attach container 6 can be used to attach hose 4.
The sprayer 2 can include an antisiphoning device 70 to prevent backflow of concentrated liquid product outwardly of inlet 8 and into hose 4. As shown in FIGS. Sa-d, device 70 includes cylindrical member 71 having a central passage 72therein for directing water to cavity 26, O-ring 72 for sealingly eng~ging an outer periphery of member 71 with an inner wall of fitting 8 and conical member 74 having a conical wall 75 and central passage 76 in fluid COllullul~iCatiOn with passage 72.
The antisiphoning device includes a flapper (not shown) to prevent backflow of fluid in the hose 4. The antisiphoning device can have other suitable configurations such as of the type incorporated in aspiration-type sprayers made by Hayes Products or comprise a backflow valve as disclosed in U.S. Patent No. 2,646,063.
As shown in FIGS. 6a-b, housing 20 includes snap fitting member 80 which engages mating projection 34 on cover 30 (see FIG. 3a). With this arrangement, cover 30 can be replaced or interchanged with another cover having different size and/or shaped outlets 31, 32. Also, cover 30 can include a deflector for diverting the water-rinse or diluted product sprayed from exit holes 31 and/or 32. For instance, as shown in phantom in FIG. 3a, cover 30 can include deflector 35 for diverting thediluted product spray thus providing a wide spray pattern for spraying the diluted product on nearby horizontal surfaces such as wooden decks, driveways, etc.
With the sprayer arrangement described above, it is possible to mix highly concentrated cleaning solution with water supplied from a garden hose and apply the thus diluted cleaning solution to outdoor surfaces. The sprayer can provide a one-foot wide spray pattern at a distance of 8 feet. Further, at a water pressure of 60 psi at the hose end, the sprayer can deliver the diluted product to heights of 30 feet and provide a rinsing spray of water-only at such distances. Moreover, the delivery of product and water-only rinse to the desired distances such as the top of a two-story wall of a building can be achieved while m~int~ining any desired yet substantially constant water/product mix ratio, e.g., 1:20 product to water ratio.
In accordance with one embodiment, a mixing ratio of about 1:20 product to water is achieved using an orifice disk with two holes having diameters of 0.031 inch and configuring the lower passage 24 such that the upstream portion 24a has a diameter of 0.092 inch and the downstream portion 24b has a diameter of 0.116 inch.
Also, water and concentrated product are mixed in downstream portion 24b which has length of 0.875 inch. The upper passage 23 for the water rinse has a diameter of 0.140 inch. This arrangement was compared to a single orifice arrangement having a orifice disk with a single hole having a diameter of 0.042 inch. The results of the testing are set forth in the following Table 1.

¦ Water Pressure40 P.S.I. 50 P.S.I. 60 P.S.I.
TimetlO Gals. Water/Product 7 Min. 5 Sec.6 Min. 10 Sec. 5 Min. 35 Sec.
Single Product Flow 54 Ozs. 64 Ozs. 76 Ozs.
Orifice Water/Product Ratio 22.70:1 19:1 15.84:1 Time/24 Ozs. Product3 Min. 9 Sec.2 Min. 19 Sec.1 Min. 46 Sec.
Time/10 Gals. Water/Product 7 Min. 6 Min. 5 Sec. 5 Min. 30 Sec.
Double Product Flow 56 Ozs. 56 Ozs. 571/2 Ozs.
Orifice Waterlproduct Ratio 21.85: 1 21.85: 1 21.26: 1 Time/24 Ozs. Product 3 Min. 2 Min. 36 Sec.2 Min. 18 Sec.

As shown in the above Table 1, with the double orifice arrangement, it is possible to m~int~in a desired product/water ratio of about 1:21 to 1:22 over a water pressure range of 40-60 psi whereas with a single orifice arrangement the product:
water ratio varied widely from about 1:16 to 1:23 over the same water pressure range.
A variation of the cover 30 is shown in FIGS. 7a-c. In this embodiment, outlets 31,32 of cover 30 can be omitted and instead a larger single opening 36 can be provided in cover 30, as shown in phantom in FIG. 3b. Opening 36 should be large enough to allow rinse water flowing through passage 23 or diluted product flowing through passage 24a to pass therethrough. In order to provide desired spray patterns for the rinse and diluted product, respectively, snap-on spray pattern member 80 includes outlets 31a,32a extending therethrough. Outlet 31a is aligned with passage 23 and outlet 32a is aligned with passage 24a when member 80 is attached to cover 30. In order to attach member 80 to cover 30, cover 30 includes openings 37,38 (as shown in phantom in FIG. 3c) and member 80 includes snap-fit projections 81,82 thereon for eng~ging openings 37,38. Each of the exit portions of outlets 31a,32a is rectangular in shape, as shown in FIG. 7c. Each outlet 31a,32a includes a first V-shaped tapered portion 83 and a second rectangular shaped portion 84 of uniform cross-section, as shown in FIG. 7a. As shown in FIG. 7c, the tapered portion 83 is formed by a pair of planar vertical walls which converge towards the portion 84 of uniform cross-section. In the embodiment shown, the outlets 31a,32a have exit openings in the shape of rectangles which are 0.092 inch in horizontaldimension and 0.20 inch in vertical dimension. The tapered portion 83 has an entrance opening in the shape of a square with dimensions of 0.20 inch on each side.
The outlets 31a,32a, however, can have any suitable size and/or shape. Thus, thearrangement shown in FIG. 7a-c allows the spray pattern to be easily changed by att~rhing member 80 having the desired size and/or shaped outlets therein.
Alternatively, a desired spray pattern for the rinse and/or diluted product can be created by a permanent or removable deflector. For instance, for applying the diluted product to horizontal surfaces such as decks and driveways, the spray gun can include a snap-on deflector which directs the diluted product downwardly into a fan shaped pattern.
As shown in FIGS. 8a-b, the orifice plate 52 can be mounted in the upper end of the tube 51. In this case, orifice plate 52 can include a single orifice 52c extending axially through projection 53. Projection 53 tightly fits within the opening of tube 51, thus allowing easy mounting of the orifice plate and simple adjustment of product dilution ratios based on the size of the opening 52c. Tube 51 can comprise a standard dip tube having an inner diameter of 0.1875 inch and an outer diameter of 0.25 inch. Projection 53 and orifice plate 52 can be molded as a single piece ofplastic or other material having a length of about 0.125 inch. With this arrangement, orifice plate 52 can be located between tube 51 and passage 28 with tube 51 sealingly eng~ging opening 29. Product dilution ratios obtainable with different hole sizes 52c are exemplified in the following Table 2.

Product/ 1:10 1:11 1:12 1:13 1:14 1:15 1:16 1:17 1:18 1:19 1:20 Water Ratio Orifice 0.043 0.042 0.041 0.040 0.039 0.038 0.037 0.036 0.035 0.034 0.033 Diarneter (inch) If desired, the orifice plate 52 can be omitted and passage 28 in housing 20 can be used to provide any desired dilution ratio. For instance, to achieve ratios of 1:1, 1:3 or 1:5, the passage 28 can be sized a~lopliately to achieve the required dilution ratio and desired flow rate (e.g., 1/6 gallon/minute). The passage 28 can comprise one or more openings provided when the housing 20 is molded. This provides a more simplified arrangement than the orifice plate arrangement. Further, while the orifice plate arrangement provides a substantially constant dilution ratio, omission of the orifice plate and sizing of passage 28 to achieve a desired ratio provides a consistent enough dilution ratio adequate for cleaning outdoor surfaces in accordance with the invention.
Fig. 9a shows the insert fitted in spray gun 100. The recess 120 in the spray gun 100 has an end wall 136 located 0.160 inch above the central axis of upstream passage 24a and upper end 132 of the insert provides an abutment which fits against the end wall 136. As shown in Fig. 9a, the inlet passage 114 has a smaller diameter than the outlet passage 116, the outlet passage 116 has a smaller diameter than the upstream passage 24a and the upstream passage 24a has a smaller diameter than the downstream passage 24b. The supply passage 118 has a diameter larger than that of inlet passage 114 but smaller than that of outlet passage 116. With this arrangement, mixing of the concentrated product occurs in the space where the water supply passage 114 and product supply passage 118 open into outlet passage 116.
The step change between water supply passage 114 and outlet passage 116 create a pressure drop which draws concentrated product through product supply passage 118 into outlet passage 116. For instance, the outlet passage 116 can be at least 50% larger in cross section than the inlet passage 114. In the embodirnentshown, the water supply passage 114 has a cross sectional area about 18% of the cross sectional area of outlet passage 116. Such an arrangement creates enough of a siphon effect to draw concentrated product upwardly through the product supply passage 118, which has a cross sectional area of about 12% of that of outlet passage 116. It will be apparent to those skilled in the art that alternative arrangements could be used for supplying the concentrated product to mix with the water.
The foregoing dimensions provide an arrangement wherein the concentrated cleaning solution can be diluted 75 % with water in a ratio of 3 parts water to 1 part concentrated cleaning solution. It will be apparent to those skilled in the art that the foregoing dimensions of the various passages can be changed relative to each other to obtain any desirable flow characteristic and/or dilution of product supplied through tube 51 whereby water:concentrated product ratios, e.g., 0.5:1 to 200:1, can be obtained.
The spray gun can include various types of deflector arrangements to deflect the water/product mixture sprayed from the spray gun in a desired direction or pattern. Examples of deflector arrangements are shown in FIGS. 11a-f, FIGS. 11a, c and e showing top views and FIGS. 11b, d and f showing side views, respectively.The rectangular deflector 300 shown in FIGS. 11a-b includes a concave bubble or recess 302 to spread a stream of water or water/product mixture into a desired pattern such as a fan-shaped pattern. The deflector 300 includes a tab 304 which fits into a mating hole in part of the spray gun, e.g. the mating hole can be in the main body or in a removable cover attached to the spray gun. FIGS. 11c-d show a deflector 310having a triangular shape, a small bubble/recess 312 for deflecting a jet stream of water or water/product mixture into a desired pattern (as illustrated by the arrows in FIG. 11d), and a tab 304 for ~ rhing the deflector 310 to a spray gun. The semi-circular deflector 320 shown in FIGS. 1 le-f includes a bubble/recess 322 and tab 304.
As shown in the side views of FIGS. 11b, d and f, the deflectors 300, 310 and 320 have thin profiles and can be relatively straight (FIG. 1 lb), bent with an obtuse angle in the middle (FIG. 11d) or bent with a small bend at the location of the tab (FIG. 11f).

The foregoing has described the principles, preferred embodiments and modes of operation of the present invention. However, the invention should not be construed as being limited to the particular embodiments discussed. Thus, the above-described embodiments should be regarded as illustrative rather than restrictive, and it should be appreciated that variations may be made in those embodiments by workers skilled in the art without departing from the scope of the present invention as defined by the following claims.

Claims (20)

1. A method for cleaning environmental soils such as mold, mildew, algae, grease and/or stains from a soiled unfinished outdoor surface including raw wood, sealed wood, unpainted concrete, unpainted brick, unpainted stucco or unpainted masonry, comprising the steps of:
forming a diluted cleaning composition by feeding a concentrated aqueous cleaning composition containing bleach and feeding water into a mixing chamber of a hand held hose end spray gun;
spraying the diluted cleaning composition from the spray gun onto the unfinished outdoor surface to be cleaned;
allowing the diluted cleaning composition to remain on the surface to be cleaned for a period of time sufficient to loosen material to be removed from the surface to be cleaned; and optionally removing the diluted cleaning composition from the surface to be cleaned by spraying rinsing water onto the surface to be cleaned.

2. The method of Claim 1, wherein water is fed into the mixing chamber through a garden hose attached to a first inlet in the spray gun, the diluted cleaning composition is fed from a container attached to the spray gun into the mixing chamber through a second inlet in the spray gun and the diluted cleaning composition and/or the rinsing water are sprayed from the spray gun through at least one outlet in the spray gun.

3. The method of Claim 2, wherein the at least one outlet comprises first and second outlets, the diluted cleaning composition being sprayed only from the first outlet and the rinsing water being sprayed only from the second outlet.

4. The method of Claim 1, wherein the diluted cleaning composition comprises an aqueous bleach solution having an available chlorine content of 0.05 to about 4.0%, an optional phosphate in an amount effective for water softening, anoptional surfactant in an amount effective for wetting of the soiled surface andpenetration into the soil, and an optional silicate in an amount effective for protecting metal and/or glass surfaces which come into contact with the cleaning composition.

5. The method of Claim 1, wherein the diluted cleaning composition is deflected and sprayed from the spray gun and deflected in a substantially uniform pattern.

6. The method of Claim 1, wherein the concentrated cleaning solution is mixed with the water to provide a 1:1 to 1:5 ratio of the concentrated cleaning solution to the water and the water is fed into the mixing chamber at a rate of 0.1 to 1.0 gal/minute.

7. The method of Claim 1, wherein the spray gun provides a dilution ratio of the concentrated cleaning solution to the water of less 1:10.

8. The method of Claim 1, wherein the spray gun comprises a closed venturi-type spray gun.

9. The method of Claim 1, wherein the diluted cleaning composition includes at least one of a builder, surfactant, corrosion inhibitor and disinfectant.

10. A method of cleaning environmental soils from outdoor unfinished surfaces including raw wood, sealed wood, unpainted masonry, unpainted concrete,unpainted stucco or unpainted brick by using a portable double barrel hand held hose end spray gun to selectively spray a water-rinse through a first outlet and spray a diluted liquid product through a second outlet, spray gun including a first inlet attached to a water hose and second inlet attached to a container of a concentrated aqueous cleaning composition containing bleach, the method comprising:

mixing the concentrated cleaning composition with water to form a diluted product and spraying the diluted product onto a surface to be treated, the diluted product being sprayed through the second outlet of the spray gun by moving a valve member of the spray gun to a position at which the first and second inlets are in fluid communication with the second outlet; and optionally removing the diluted product from the surface by spraying a water-only rinse onto the surface, the water-only rinse being sprayed through the first outlet of the spray gun by moving the valve member of the spray gun to a position at which the first inlet is in fluid communication with the first outlet.

11. The method of Claim 10, wherein the concentrated liquid product is siphoned from the container and passes through a passage in the spray gun which provides a desired dilution ratio over water pressure variations in the water supplied through the inlet ranging from 20 to 90 psi.

12. The method of Claim 10, wherein the spray gun includes a housing having first and second passages, the first passage being in fluid communication with the first outlet and the first inlet, the second passage being in fluid communication with the second outlet and the first and second inlets, the mixing being carried out in the second passage and the water-only rinse being supplied through the first passage.

13. The method of Claim 10, wherein the spray gun includes a housing having the first and second outlets therein and a cover mounted on the housing, the cover including a first outlet in fluid communication with the first outlet of the housing and a second outlet in fluid communication with the second outlet of thehousing, the first and second outlets in the cover providing different spray patterns of the water-only rinse and diluted product, respectively.

14. The method of Claim 10, wherein the valve member includes first and second passages therethrough, the first passage being in fluid communication with the first inlet and first outlet when the valve member is in the first position and the second passage being in fluid communication with the first inlet and the second outlet when the valve member is in the second position.

15. The method of Claim 10, wherein during the mixing step the concentrate is diluted 1:0.5 to 1:200 concentrated cleaning solution to water.

16. The method of Claim 10, wherein the concentrated liquid product is siphoned from the container and is mixed with the water in a mixing chamber of the spray gun.

17. The method of Claim 10, wherein the housing includes a removable deflector which deflects and spreads the diluted product in a substantially uniform pattern.

18. The method of Claim 10, wherein the spray gun includes a housing having the first and second outlets therein and a cover mounted on the housing, the cover including a first outlet in fluid communication with the first outlet of the housing and a second outlet in fluid communication with the second outlet of thehousing, each of the first and second outlets in the cover including a tapered portion receiving the diluted product or water-only rinse sprayed through the first and second outlets of the housing.

19. The method of Claim 10, wherein the spray gun provides a dilution ratio of the concentrated cleaning solution to the water of less 1:10.

20. The method of Claim 10, wherein the spray gun comprises a hand held hose end sprayer of the closed venturi type.