WO2010030848A2

WO2010030848A2 - System and associated method for applying friction-modifying coatings

Info

Publication number: WO2010030848A2
Application number: PCT/US2009/056611
Authority: WO
Inventors: Jeff Rainwater; Keith Rainwater; Martin Macdonald
Original assignee: High-Friction Surfacing, Llc
Priority date: 2008-09-11
Filing date: 2009-09-11
Publication date: 2010-03-18
Also published as: WO2010030848A3

Abstract

A method for the application of friction-modifying coatings to roadways, walkways, pathways and other areas subject to vehicular, human or animal traffic, the method comprising the controlled, simultaneous application of binder and filler to a surface of a substrate, using a mobile device which passes over the substrate as the binder and filler are being applied. Both the binder and the filler are precisely and accurately metered onto the substrate, ensuring uniform coating thickness and performance. The method of this invention also enables the use of different binding systems and precise control over mixing ratios for multi-component binders.

Description

SYSTEM AND ASSOCIATED METHOD FOR APPLYING FRICTION-MODIFYING COATINGS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/096,114, filed September 11, 2008, which application is hereby incorporated herein by reference, in its entirety.

TECHNICAL FIELD

[0002] The invention relates generally to a system, and associated method for applying friction-modifying coatings to a surface, and more particularly, for automating the application from a mobile platform of friction-modifying coatings to a surface of a substrate.

BACKGROUND

[0003] The construction and public safety industries are constantly looking for means to make substrates, such as roadways, pathways, and other high-use areas, safer for vehicular and human traffic. One developing area is the application of friction-modifying coating to surfaces of substrates to help increase their coefficient of friction, thereby reducing slippage and skidding, making them safer for their intended use. In particular, the roadway industry is trying to reduce the number of accidents caused by loss of tire grip on bridges, curves, intersections, and school zones. Speed, tire condition, and weather conditions can all play a role in these accidents; however, studies have found that increasing the coefficient of friction of the roadway through the use of high friction coatings can increase tire grip, regardless of the weather conditions or nature or condition of the tires.

[0004] Currently, few surfaces are being treated with friction-modifying coatings. The surfaces that have been coated are typically being done manually. For example, in the case of a two-component epoxy system, the most common type of binder, the process conventionally starts when a laborer opens the spigot of a tote containing the epoxy resin, adding it manually to a garbage can or similar container. The spigot is closed when resin reaches a predetermined level in the garbage can. A second spigot on a second tote containing a catalyst hardener is then opened, adding the hardener to the resin until a second, predetermined level is reached in the garbage can. In some instances, five gallon pails of hardener and resin are combined in the garbage can. The resin and hardener are then mixed, using a mixing blade attached to a hand drill. [0005] The mixed epoxy is then poured out onto the surface to be coated by tipping the garbage can over or dipping smaller buckets into the garbage can and then pouring the composite epoxy out of the smaller container onto the surface to be coated. The epoxy is then spread over the surface, using a squeegee or similar device. [0006] Once the epoxy is on the surface of the substrate, laborers manually shovel a friction-modifying filler onto the epoxy binder. Manually operated blowers and similar instruments have also been used to distribute the friction-modifying filler. The most common filler is bauxite which, once applied, partially sinks into the epoxy. The epoxy, when it has hardened, acts to bind the filler to the substrate, creating a uniform coating. Because the filler is irregularly shaped, typically jagged and protruding from the epoxy, it acts to increase the friction coefficient of the surface.

[0007] There are a number of drawbacks to the conventional method of application described above. For example, conventional methods utilize a multi-part binder which is manually poured, mixed, and applied to the substrate. Combining the multi-part binder is done using a significant amount of human judgment and imprecise measuring techniques, which introduce error into the component mixing ratios. Most multi-part systems have an ideal ratio of resin and catalyst. Too much of either one of these components can detrimentally affect the properties and performance of the hardened product including, but not limited to, durability, degradation, filler binding, ductility, and frictional properties. [0008] Furthermore, the conventionally practiced method of coating preparation utilizes manual mixing of the components. There is the potential for the components not to be mixed adequately, resulting in pockets of epoxy wherein the ratio of resin to hardener is not optimal. This variability can ultimately affect the quality of the binder, adhesion to filler, the degree of curing and/or the curing time. [0009] Additionally, if the mixing time of the binder is too long and the binder starts to cure prior to application on the substrate, it may reduce the spreadability and substrate adhesion as well as filler penetration and adhesion.

[0010] Furthermore, in the conventional practice of application, the binder is spread on the surface using a squeegee or the like which results in significant variability in the thickness of the binder across the surface of the substrate. As a result, the binder can be too thick in some places and too thin in others. Thick binder can increase drying times and delay the surface availability. Moreover, it can also diminish the integrity of the coating as well as the performance of the coating if the filler is fully enveloped by the binder and does not stick up from its surface. Similarly, binder that is too thin can reduce the integrity and performance of the binder by not providing enough material to hold the filler in place or adhere it to the substrate.

[0011] The way the filler is added to the binder can also influence the quality, performance and integrity of the coating. In the conventional method of application when the filler is shoveled or blown onto the surface of the wet binder, it has the tendency to impact the surface of the binder and displace it away from the impact zone. Thus the filler uniformity and overall coating density can vary significantly. In areas with too much filler, the integrity of the coating can be reduced. In areas with too little filler, the frictional properties of the coating can be reduced.

[0012] Therefore, what is needed is a system and method for applying friction- modifying coatings to a surface, without incurring the many drawbacks discussed above.

SUMMARY

[0013] The present invention, accordingly, provides a system and method for applying friction-modifying coatings to a surface using automated equipment mounted on a mobile platform, such as a truck, trailer, cart or the like, to make a simultaneous application of binder and filler to a surface of a substrate. The mobile platform is preferably driven or pulled across the surface to be coated while the binder and filler are applied to the substrate. Preferably, the application of binder, which can be single or plural component in nature, is located closer to the front of the mobile platform (i.e., toward the direction of forward movement), such that the binder gets applied to the road and, as the mobile platform moves forward, the filler is then added to the binder. Thus, the time between the application of the binder and the addition of the filler is very short, such as less than a few seconds.

[0014] The method enables the precise and uniform application of the coating by mechanically controlling and metering both the binder and filler. This ensures good control over coating thickness and binder-to-filler ratios, enabling the coating to be optimized to the surface and desired friction performance. In the case of plural component binders, the method of this invention preferably utilizes inline mixers located immediately before the application nozzles to ensure excellent component mixing. [0015] The method of this invention has several advantages over conventional means of applying friction-modifying coatings to substrates. For example, the method of this invention has the benefit of decreasing the amount of manual labor required to apply binder and filler to the substrate. The conventional method employs manual labor to mix binder, apply binder to substrate, apply filler, and remove excess filler. Using the method of this invention, the processes of mixing and application of binder and filler are fully automated, thereby reducing the amount of labor required to apply the system to the substrate.

[0016] A further advantage of this invention is the increased safety benefit to the workers applying the friction-modifying coating. In roadway application, the friction-modifying coating is generally applied after traffic is blocked off in one or more lanes, using barricades and the like. Although signs and markers are used to divert traffic, laborers still are at risk of being hit by vehicular traffic. In the method of this invention, the mixing and application equipment is preferably mounted on the back of a truck or trailer pulled by a motorized vehicle, reducing the number of people required to openly walk on the roadway, exposed to traffic.

[0017] A further benefit of this invention is an increase in the application rate of the friction-modifying coating. The conventional method of application results in an application rate of approximately 1,000 square yards per day. Using the method of this invention, the application rate can be increased to over 10,000 square yards per day, although conventional rates of application are possible if desired. This will have the benefit of decreasing the amount of time required to complete a project as well as a reduction in the disruption of the traffic, due to closure of the surface being coated.

[0018] A further benefit of this invention is a reduction in the time that transpires from the time the binder is applied to the substrate and the time the filler is added to the binder. For the previous methods of application, several minutes can pass before the filler is added to the binder. This is the result of the time required to mix and then manually apply the binder and then the filler to the binder. The method of this invention results in the filler being added almost immediately to the binder in sequence and in virtually a one-step process. The lapsed time between application of the binder and addition of the filler should be short, preferably less than 5 seconds. This results in greater filler penetration and a more durable coating.

[0019] Another benefit of this invention is the uniformity of the friction-modifying coating and filler within the composition. Under the conventional methods of application, the filler is added to the binder either by manually shoveling it, or through the use of a manually operated blower. Both of these conventional methods result in variability in the filler density per square foot of substrate surface, and patches containing too much filler and others not containing enough filler. The method of the present invention results in the uniform application of filler across the width and length of the surface being coated. Thus, there is high uniformity of filler density per square foot, and the filler density can be controlled at an optimal value to ensure a desired friction coefficient with the least amount of filler. The correct filler density also has the added benefit of ensuring the best ratio of filler and binder to produce the greatest coating strength, integrity, and durability.

[0020] In the case of multi-component binders, the method of the present invention has the benefit of enabling accurate metering and control over the component ratio, excellent component mixing, and rapid application after the components are mixed. The use of automated flow controls ensure the desired component flow ratios, and the use of inline mixers located proximate to application ensure good mixing of components. The short duration of time from mixing until application, has the benefit of ensuring that the mixed binder is applied quickly at the ideal curing point and temperature, which in turn will ensure excellent filler penetration, substrate adhesion, and coating uniformity.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

[0022] FIGURE 1 is a schematic view exemplifying a mobile platform embodying features of the present invention; and

[0023] FIGURE 2 is a perspective view of a system for automating the application of friction-modifying coatings from a mobile platform, in accordance with principles of the present invention.

DETAILED DESCRIPTION

[0024] The invention relates to the controlled preparation and application of friction- modifying coatings, comprising a binder and filler, to surfaces subject to vehicular, human, and/or animal traffic. Friction-modifying coatings are applied to areas where the friction coefficient of the surface needs to be increased in order to reduce skidding or slipping, making it safer and/or better for its intended purpose. Included in the many substrate surfaces which can benefit from the application of these coatings are pathways, walkways, highways and roadways, bridge decks, parking lots, school zones, road crossings, railway crossings, dangerous intersections, bike lanes, toll lanes, sharp corners, intersections, overpasses, hospital zones, playgrounds, gymnasiums and the like.

[0025] In the discussion of the FIGURES, the same reference numerals will be used throughout to refer to the same or similar components. In the interest of conciseness, various other components known to the art, such as metering devices, pumps, positive displacement pumps, screw pumps, extruders, valves, control valves, orifices, flow controllers, nozzles, spray nozzles, extruders, brushes, jets, impellers, blowers, rollers, orifices, pipes, tubes, knives, ribboners, motorized mixers, mixing screws, paddles, impellers, propellers, in-line mixers, static mixers, minerals, rocks, metals, metal oxides, hydrates, hydroxides, salts, silicates, epoxy hardener and resin, and the like, have not been shown or discussed in any detail as such are considered to be well-known to those skilled in the art.

[0026] Referring to FIGURE 1 of the drawings, the reference numeral 100 generally designates a multi-part coating system embodying features of the present invention. The system 100 includes a mobile platform 102 on which are positioned a number of components of the invention. One or more storage vessels or containers 102 are positioned on the platform 102 for containing various binder components, discussed in further detail below. These storage vessels may be operated at atmospheric or elevated pressure. One or more metering devices 108, such as pumps, positive displacement pumps, screw pumps, extruders, valves, control valves, orifices, flow controllers or the like, or a combination thereof, as know to those skilled in the art, are coupled via lines 106 to the containers 104 for conveying or metering the components contained within the containers. At least one mixer 112 is preferably, though optionally, coupled via lines 110 to one or more pumps 108 for receiving and mixing components pumped from the pumps 108, although mixing can alternatively occur directly in lines 114 and 116 if the mixer 112 is not present. The mixer 112 is preferably coupled via lines 114 and 116 to one or more binder application nozzles 118, such as spray nozzles, extruders, brushes, jets, impellers, blowers, rollers, orifices, pipes, tubes, knives, ribboners, and the like, effective for applying fluids to a substrate.

[0027] A hopper 122 is preferably also positioned on the mobile platform 102 for storing filler to be added to the binder, as discussed in further detail below. Preferably, one or more flow zones and/or zone flow controllers 120 are coupled to the hopper for metering filler to be applied onto the binder. The number of hopper flow control zones is preferably the same as the number of binder nozzles. A curing zone 124 is optionally identified proximate to the filler hopper 122. Preferably positioned proximate to the curing zone would be equipment or means for expediting or facilitating binder curing, including equipment for blowing air onto the binder, or applying to the binder radiation, infrared (IR) light, ultraviolet (UV) light, heat, microwaves, and/or the like. [0028] In a preferred embodiment of the invention, a portion of the surface of the substrate 202 is designated as a heating zone 125 which is heated or dried, prior to application of the binder, using any suitable technique, such as hot air, radiation, UV light, IR light, microwaves or the like, to prepare the surface of the substrate and facilitate adhesion of the binder to the surface.

[0029] The method of the invention comprises the use of a multi-part coating system, preferably comprising a binder and a filler embedded in the binder. The binder acts as a matrix to suspend and hold the filler in place and cause it to adhere to the surface of the substrate. The filler acts to change the friction coefficient of the surface by protruding from the binder or otherwise increasing the overall coefficient of friction. This is similar, for example, to how sandpaper, a totally different product, works. In sandpaper, paper forms a substrate, the binder is an adhesive, and the filler is sand. The adhesive acts to bind the sand to the paper in such a way as to keep a portion of the pieces of sand above the surface of the adhesive, thereby changing the friction coefficient of the paper. In a comparable way, the method of the invention applies binder and filler to surfaces of a substrate (e.g., roads, highways, and the like) subject to traffic, thereby modifying the frictional properties of the surfaces.

[0030] According to a preferred method of the invention, the filler and binder are metered and applied to the substrate in an automated, continuous, virtually one-step process that results in better coating integrity, uniformity, durability, and reduced application time. The binder is preferably a single or plural component binder that is preferably stored in one or more storage vessels or containers 104 on the mobile platform 102. In the case of a single component binder that is solid at ambient conditions, heat may optionally be added to storage containers 104 and/or lines 106 to liquefy the binder and enable it to be more readily transferred through lines, piping, or the like. The flow of the binder is precisely metered using metering devices 108, such as positive pumps, displacement pumps, screw pumps, extruders, valves, control valves, orifices, or the like, or a combination thereof.

[0031] For multi-component binders, the various components are preferably mixed by way of a mixer 112, and are then passed via lines 114 and 116 to application nozzles 118, such as spray nozzles, extruder, rollers, orifices, pipe, tube, knives, ribboners, and the like, effective for applying fluids to a substrate. For single component binders, the mixer 112 is not needed, and the binder preferably flows directly to application nozzles 118 (b-zone 1 to b-zone x). Similarly, multi-component binders may be mixed in lines 114 and 116. [0032] Within a short time, preferably less than five seconds, of application of the binder to the substrate 202 (FIG. 2), the filler contained in hopper 122 is metered through zone flow controllers 120 (f-zone 1 to f-zone x) and applied onto the binder. The number of hopper flow control zones 120 is preferably the same as the number of binder nozzles 118. The width of application is controlled by controlling the number of binder application nozzles and hopper flow control zones used. Additional conveyers (not shown) may be used to more uniformly distribute the filler across the width of the binder. Following application of binder, and either before or after the application of filler, accelerators such as UV or IR radiation, heat, microwaves, and/or the like, may be used to facilitate or accelerate the curing of the binder. [0033] For plural component binders, the binder first flows through lines 110 to one or more mixers 112, through the lines 114 and 116, and then through the application nozzles 118. The one or more mixers 112 preferably comprise contained motorized mixers, mixing screws, paddles, impellers, propellers, in-line mixers, static mixers, and/or the like, effective for uniformly mixing a plurality of components. The binder then flows to application nozzles 118 proximate to b-zone 1 to b-zone x, the nozzles comprising spray nozzles, extruder, rollers, orifices, pipe, tube, knives, ribboners and the like, effective for applying fluids to a substrate. The filler is preferably applied as discussed above after the binder has been applied to the substrate 202.

[0034] In one alternative embodiment of the invention, the filler and binder are mixed prior to application and then applied at the same time. In accordance with this embodiment, the filler and binder are metered into a mixing zone comprising a section, such as a vessel, tank, channel, pipe, box, or other suitable means effective for creating contact between a plurality of components prior to application on the substrate. A mixing device such as a paddle, blade, impeller, propeller, screw, conveyor, tumbler or the like, effective for mixing a plurality of components, may be used to mix the filler and binder.

[0035] The binder can be a one or multiple part system, comprising one or more of polymers, elastomers, thermoplastics, thermosets or the like including vulcanized rubbers, Bakelites, urea-formaldehydes, melamine resins, epoxy resins, polyamides, plastics, peroxides, silanes, cross-linked metallic compounds, isocyanates, resins, polyethylenes, polypropylenes, polystyrene, polymethylmethacrylate, vinyls, Polybutylene terephthalates, polyureas, polycarbonates, Polyethylene terephthalates Acrylonitrile butadiene styrene (ABS) acrylics, celluloids, cellulose acetates, ethylene -vinyl acetates, ethylene vinyl alcohols, fluoroplastics, ionomers, Kydex, liquid crystal polymers, polyacetals, polyacrylates, Polyacrylonitriles, polyamides, Polyamide-imides, polyaryletherketones, polybutadienes, polybutylenes, Polybutylenes terephthalates, polycaprolactones, polychlorotrifluoroethylenes, natural Rubbers, synthetic polyisoprenes, butyl rubbers, halogenated butyl rubbers, polybutadienes, styrene- butadiene rubbers, polybutadiene, nitrile Rubber, hydrogenated nitrile rubbers, polychloroprenes, ethylene propylene rubbers, ethylene propylene diene rubbers, epichlorohydrin rubbers, polyacrylic rubbers, silicone rubbers, fluorosilicone rubbers, fluoroelastomers, Vitons, Tecnoflons, fluorels, aflas, Dai-Els, perfluoroelastomers, tecnoflon PFR, Kalrez, Chemraz, Perlast, polyether Block Amides, chlorosulfonated Polyethylenes, ethylene -vinyl acetates, thermoplastic elastomers, thermoplastic vulcanizates, thermoplastic Polyurethane, thermoplastic olefins, polysulfide Rubbers, polyethylene terephthalates, polycyclohexylene dimethylene terephthalates, polycarbonates, polyhydroxyalkanoates, polyketones, polyesters, polyethylenes, polyetheretherketones, polyetherimides, polyethersulfone, polysulfones, polyethylenechlorinates, polyimides, polylactic acids, polymethylpentenes, polyphenylene oxides, polyphenylene sulfides, plyphthalamides, polypropylenes, polystyrenes, polysulfones, polyurethanes, polyvinyl acetates, polyvinyl chlorides, polyvinylidene chlorides, spectral on, styrene-acrylonitrile and/or the like. Various additives such as viscosity modifiers, catalysts, accelerators, UV protectors, inhibitors, anti-oxidants, repellants, oils, and the like can be added to the binder to change its physical or chemical properties to enhance characteristic such as pumpability, spreadability, curing rate, cured binder properties, ductility, motility, hardness, adhesion cohesion sprayability, extrudability, durability, wear rate, applyability, oxidative stability, thermal stability, UV stability, and the like.

[0036] It is preferable that the binder, once applied and cured, be solid or semi-solid at the normal, or ambient, operating conditions of the substrate. The binder is preferably applied as a liquid which then solidifies once it is applied to the substrate; however, it is possible to apply solids such as powders, pellets, or the like directly to the substrate and subsequently melt, react, or dissolve them to form a uniform coating. In the case of a liquid binder, the binder is applied as a liquid which cures and hardens after application to the substrate through chemical or physical changes, such as cross-linking, curing or solidification, and/or the like. For example, if a thermo-plastic is used as the binder, the thermoplastic may be heated above its melting point, prior to its application to the substrate, until it becomes a fluid. Thereafter, the fluid cools to a uniform solid. If a multi-component liquid binder is used, then the liquid parts are preferably combined prior to application and cure into a solid. Heating may be used depending on the binder to change the physical properties of the binder to enhance pumping and/or ease of application. Optionally, a liquid binder may be applied to the substrate, and radiation, heat, microwaves, light, and/or the like may be used to cure the binder.

[0037] The binder is preferably applied to the substrate by spraying, rolling, brushing, extruding, wiping, squeegeeing, ribboning, baring and/or the like. [0038] The filler is preferably added to the binder prior to hardening or curing in a metered fashion at a rate calculated to attain a desired density and respective coating frictional properties. The filler preferably comprises one or more minerals, rocks, metals, metal oxides, hydrates, hydroxides, salts, silicates, plastics, polymers, glasses, halides, sulfides, phosphates, carbonates, carbon, oxides, ores, and/or the like. The filler is preferably applied to the binder through a hopper or similar device which temporarily stores the filler. Application of the filler to the binder preferably occurs through a drop or rotary spreader, blower, conveyor, screw, or similar material transfer device.

[0039] Other fillers, catalysts, or performance-enhancing materials can also be added to the binder to enhance the properties of the friction-modifying coating. By way of example, but not limitation, fillers, catalysts, or performance-enhancing materials may include catalysts, compatabilizers, ultra-violet stabilizers, thermal stabilizers, oxidative stabilizers, chemical stabilizers, wear resistance modifiers, reflectivity enhancers, water repellants, oil repellants, ice repellants, co-polymers, rubbers, pigments, and/or the like, effective for changing the properties or performance of the coating. [0040] The application of the binder and filler are preferably mechanically linked in close proximity to each other on a mobile platform 202, such as a truck or trailer, which passes over the substrate to be coated. However, in an alternative embodiment, the binder can be applied from one mobile platform and the filler can be applied from another mobile platform. As the mobile platform(s) moves forward, the binder is precisely metered and applied to the substrate 202. Within a short period of time, because the platform(s) is (are) moving forward, the filler is metered and precisely added on top of the binder. Both the binder and filler are added in proportion to the speed of the mobile platform(s) to ensure the proper application thickness and proportions of filler and binder. Once the binder has hardened, the excess filler is collected and reused. [0041] FIGURE 2 is a drawing of one preferred embodiment of the invention. In the preferred embodiment of the invention, the friction-modifying coating is applied to the surface, whose properties are to be modified, from the back of a truck, trailer, or similar mobile platform 100 which travels over a substrate 202 at between about 0.1 and 5 miles per hour, although speeds of up to 30 miles per hour or even faster could be used in certain applications. The mobile platform 100 will travel over the surface or substrate 202 to be coated, and apply the coating as it moves forward. The mobile platform 100 is typically between about 1 and 30 feet wide, and preferably between about 8 and 12 feet wide. [0042] The preferred binder is a two part epoxy comprising a catalyst (hardener) and a resin. The hardener and resin are stored in receiving vessels 104 on the mobile platform 100. Each part of the epoxy, individually, is preferably filtered and then conveyed using positive displacement pumps 108, or similar means of material transfer and control, to one large static mixer 112, or preferably a series of smaller static mixers 112, located in close proximity to a series of application nozzles 118. The ratio of the two parts of the epoxy is precisely controlled by adjusting the ratio of the flow or hardener to the flow of resin using a hardener pump and/or resin pump. The ratio of resin to hardener differs with the epoxy system, but conventionally varies from approximately 5 parts resin and 1 part hardener to 1 part resin and 5 parts hardener. In one preferred embodiment, an approximate ratio of one part resin to one part hardener is used. [0043] In the preferred embodiment of the invention, the application rate of the binder is adjusted to produce a thickness of between about 1 mil and 500 mils, and preferably between 40 and 80 mils. The desired application thickness is determined by the substrate 202 properties, service, climate, filler properties, desired frictional properties, and/or the like. Using the method of this invention the thickness can be precisely controlled by varying the speed of the mobile platform 100 and the total flow rate of the binder.

[0044] In the preferred embodiment of the invention, a series of between 1 and 20 inline mixers 112, preferably helical static mixers, are used to combine and uniformly mix the two parts of the epoxy, although other mixer types can also be used. Preferably, the number of inline mixers 112 corresponds to the number of application nozzles 118; however, it is possible to use one mixer and then feed each of the application nozzles 118 from the one mixer. The inline mixers 112 are designed to ensure thorough mixing of the hardener and resin prior to application through the nozzles 118.

[0045] The binder is preferably applied to the surface of the substrate by spraying, ribboning, extruding, and/or similar means of application, through between 1 and 20 nozzles 118. The application nozzles 118 are located over the width of the mobile platform 100 in such a way as to produce a uniform coating across that width on the substrate 202. Flow to each application nozzle 118 can be adjusted or turned off, thereby enabling the overall width of the binder to be adjusted to the desired application width. In a preferred embodiment, 4 to 12 application nozzles 118 are used, depending on the desired coating width. A bar, squeegee, and/or the like, can be used to help regulate binder uniformity and thickness.

[0046] Within a short time after the binder is applied to the substrate, preferably less than 5 seconds, the filler is added to the binder. The time lapse between the application of the filler and the application of the binder should be sufficiently short to ensure that the filler adequately penetrates the binder and good adhesion occurs. In the preferred embodiment of this invention, the filler is applied from hopper 122 through 1 to 20 zone flow controllers, and preferable 4 to 12 zone flow controllers 120 onto the binder at a rate of between about 0.5 and 45 kilograms per square meter, and preferably between about 3.5 and 9 kilograms per square meter. The zone flow controllers 120 may comprise broadcast spreaders, drop spreaders, blowers, pumps, screws, conveyors, or other similar device. The filler is contained in a hopper 122 positioned on the mobile platform 100. The preferred filler is bauxite with a particle size in the range of between about 10 microns and 100,000 microns, and preferable between about 800 microns and 2,000 microns. The bauxite filler preferably flows by gravity, although mechanical conveyance can be used, through a flow control zone gates 120 on the bottom of the hopper 122, which meters the flow rate, onto a distributor 208 and finally onto the surface of the binder. Because the density of the bauxite is greater than that of the epoxy, it will tend to sink down into the epoxy. A sufficient quantity of filler is added to ensure that a portion of the filler is left protruding from the binder. As the epoxy hardens, it will bind to both the filler and the substrate, creating a strong, uniform coating.

[0047] In an alternate embodiment of this invention, a thermoplastic binder is used instead of an epoxy binder. In this embodiment, thermoplastic melting units are positioned on the mobile platform 100 which act to liquefy the plastic, making it pumpable. A pressurization and material metering device is used as described herein to provide a means of material transfer and control. In this embodiment, static mixers are not used and the thermoplastic flows directly to the nozzles, where it is applied to the substrate.

[0048] In a further alternate embodiment of this invention, reflective material is mixed with the filler or added through a separate hopper, in close sequence with the addition of the filler, to the binder. The reflective material preferably comprises glass beads or other suitable material, which would help to increase the light reflectivity of the coating. This provides the additional benefit of making potentially hazardous areas more visible at night. Similarly, pigments or other colored fillers could be added to change the appearance of the coating. [0049] In a still further alternate embodiment of this invention, the filler is added to the binder by blowing it onto the surface, using air conveyance. The filler is aspirated into an air stream and blown through one or more nozzles onto the binder surface. This process may have the added benefit of providing a greater downward force for the filler, resulting in greater binder penetration and adhesion.

[0050] In a still further alternate embodiment of the invention, the filler is applied to the binder by means of a conveyor or other such flow control devices used to move and meter solids. In this instance the speed of the conveyor can be used to control the flow of filler and adjust the ratio of filler to binder. [0051] In a still further alternate embodiment of this invention, more than one mobile platform 102 can be used to store, heat, meter, mix and apply the binder and store, meter, and apply the filler. For example, the binder storage, metering, mixing, and application could be performed from one mobile platform, and the storage, metering, and application of the filler from another mobile platform. In this embodiment, a first mobile platform comprising the binder system would apply the binder to the substrate, and a second mobile platform comprising the filler would follow the first platform and would add the filler to the binder.

[0052] Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered obvious and desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.

Claims

1. A method for applying a friction-modifying coating to a surface of a substrate of which it is desirable to modify the friction coefficient, the method comprising steps of: applying a binder from a mobile platform to the surface of the substrate; and applying a friction-modifying filler from the mobile platform to the binder.

2.The method according to claim 1 wherein the binder is an adhesive.

3. The method according to claim 1 wherein the binder is a multi-component adhesive.

4.The method according to claim 1 wherein the binder is polymeric based.

5. The method according to claim 1 wherein the binder is a multi-component polymer having two parts.

ό.The method according to claim 1 wherein the binder is an epoxy.

7.The method according to claim 1 wherein the binder is a multi-component adhesive or polymer constituting part of a coating system manufactured by at least one of Ennis Paint, Cargill, Prismo, Crafco, SSI, Epoplex, and Polycarb.

8.The method according to claim 1 wherein the binder is applied through at least one of spraying, extruding, ribboning, brushing, blowing, pressing, rolling, pouring, ironing, and smoothing.

9.The method according to claim 1 further comprising the step of applying the binder through multiple zones.

10. The method according to claim 1 wherein the binder is a multi-component adhesive, and wherein the method further comprises the step of mixing the components of said binder immediately prior to application.

11. The method according to claim 1 wherein the binder is a multi-component adhesive, and wherein the method further comprises the step employing mechanical means to mix the components of said binder immediately prior to application.

12. The method according to claim 1 wherein the binder is a multi-component adhesive, and wherein the method further comprises the step employing an in-line mixer to mix the components of said binder immediately prior to application.

13. The method according to claim 1 wherein the binder is a multi-component adhesive, and wherein the method further comprises the step employing a helical, static in-line mixer to mix the components of said binder immediately prior to application.

14. The method according to claim 1 further comprising the step of mechanically metering the binder to control its flow rate.

15. The method according to claim 1 wherein the binder is a multi-component adhesive, and wherein the method further comprises the step mechanically metering the components of said binder prior to mixing to ensure at least one of optimal blending ratios and flow rate.

16. The method according to claim 1 wherein the binder is a multi-component adhesive, and wherein the method further comprises the step mechanically metering the components of said binder prior to mixing to ensure optimal blending ratios, wherein the step of metering is performed using at least one of pumps, control valves, positive displacement devices, and orifices.

17. The method according to claim 1 wherein the friction-modifying filler comprises at least one of rock, mineral, metal, and polymeric materials, said polymeric materials including at least one of oxides, hydroxides, sulfides, sulfates, nitrides, nitrates, silicates, salts and derivatives thereof, and wherein a principal component of the filler is mineral, metallic, or polymeric -based.

18. The method according to claim 16 wherein the friction-modifying filler is silica- based.

19. The method according to claim 16 wherein the friction-modifying filler comprises bauxite.

20. The method according to claim 16 wherein the friction-modifying filler comprises bauxite which is defined by a mesh size between 10 and 10,000 microns.

21. The method according to claim 1 further comprising the step of adding property- modifying components, comprising at least one of fillers, pigments, glass, chemicals, minerals, rubbers, and polymers, to at least one of the binder and the friction-modifying filler to enhance specific properties of the coating including at least one of color, visibility, reflectivity, water repellency, ice and snow formation or adhesion, hardness, degradation, aging, wear resistance, oxidization, UV resistance, hardness, cure rate, and thickness.

22. The method according to claim 1 further comprising the step of adding at least one of pigments, dyes, powders, inks, stains, and paints to at least one of the binder and the friction-modifying filler to modify the color of the friction-modifying coating.

23. The method according to claim 1 further comprising the step of adding viscosity modifiers comprising at least one of resins, starches, polymers, plastics, rubbers, oils, esters, powders, methacrylates, isoprenes, stryrenes, and copolymers to the at least one of the binder or the filler to change the viscosity of the binder or the friction-modifying coating.

24. The method according to claim 1 further comprising the step of adding reflectivity modifiers comprising at least one of beads, glass, silicates, metals, rock, and plastics to at least one of the filler and the binder to change the reflective properties of the friction-modifying coating.

25. The method according to claim 1 wherein the degradation protectors comprise at least one of stabilizers, antioxidants, free radical scavengers, UV absorbers, thiols, phenols, polyphenols, amines, and wherein the method further comprises the step of adding said degradation protectors to at least one of the filler and the binder to reduce degradation of the friction-modifying coating.

26. The method according to claim 1 wherein the wear resistant modifiers comprise at least one of polymers, minerals, plastics, rubbers, metals, salts, rocks, aggregate, and organic fibers, and said method further comprises adding said wear resistant modifiers to at least one of the filler and the binder to change the physical properties of the friction-modifying coating.

27. The method according to claim 1 wherein the step of applying a friction- modifying filler further comprises using mechanical means to apply said friction-modifying filler from said mobile platform to said binder.

28. The method according to claim 1 wherein the step of applying a friction- modifying filler further comprises using at least one of a conveyor, blowers, and drop and/or rotary spreader to apply said friction-modifying filler.

29. The method according to claim 1 further comprising the step of metering the filler onto the binder.

30. The method according to claim 1 further comprising the step of using mechanical means to meter the binder onto the surface of said substrate.

31. The method according to claim 1 further comprising the step of metering the binder by controlling the size of at least one of an opening, a gate or an orifice.

32. The method according to claim 1 further comprising the step of using multiple control zones to regulate the placement and flow rate of said filler.

33. The method according to claim 1 wherein the steps of applying binder and of applying filler are performed in one continuous operation.

34. A method according to claim 1 wherein the steps of applying binder and of applying filler are preformed using two or more mobile platforms in tandem.

35. The method according to claim 1 wherein the steps of applying the binder and applying the filler are performed in one continuous operation and wherein the binder is applied first followed by the filler.

36. The method according to claim 1 wherein the mobile platform is at least one of a truck and trailer, and wherein the method further comprises the step of precisely controlling the speed of said mobile platform.

37. The method according to claim 1 wherein the mobile platform comprises at least one of a truck, trailer, cart, and flatbed.

38. The method according to claim 1 wherein the steps of applying the binder and applying the filler further comprise mechanically adjusting the application rate of the binder and filler according to the speed of the mobile platform.

39. The method according to claim 1 wherein the substrate is one of asphalt, concrete, and polymeric.

40. The method according to claim 1 wherein the substrate is one of a roadway, runway, parking lot, playground, traffic circle, and bridge.

41. The method according to claim 1 further comprising the step of heating the substrate prior to the step of applying the binder.

42. The method according to claim 1 further comprising the step of heating the binder prior to the step of applying the binder.

43. The method according to claim 1 wherein the binder is a multi-component adhesive, and wherein said method further comprises steps of heating each component of said binder and then mixing together each component of said binder.

44. The method according to claim 1 further comprising a step of curing of the binder using at least one of forced air, UV radiation, microwaves, infra red radiation, and heat.

45. The method according to claim 1 further comprising steps of storing binder in at least one binder storage vesseland operating said at least one binder storage vessel under pressure.

46. The method according to claim 1 further comprising steps of storing binder in at least one binder storage vessel and heating said at least one binder storage vessel.

47. The method according to claim 1 further comprising the steps of heating at least one of the filler and the binder prior to the respective steps of applying said binder and applying said filler.

48. The method according to claim 1 wherein the step of applying the filler is performed within one minute of performing the step of applying the binder to the surface of the substrate.

49. The method according to claim 1 wherein the step of applying the filler to the binder is performed from a height of no greater than two feet above the substrate.

50. The method according to claim 1 wherein the step of applying binder is performed continuously over a width of between one foot and twenty feet

51. A method for applying a friction-modifying coating to the surface of a substrate of which it is desirable to modify the friction coefficient, the method comprising steps of: preparing a binder; metering the binder into an applicator system; applying the binder to the surface of the substrate; and applying a friction-modifying filler to the binder.

52. The method of claim 51 further comprising the step of curing the binder.

53. The method according to claim 51 further comprising the step of curing the binder using one or more of forced air, radiation, microwave, thermal, ultraviolet, and infrared treatment.

54. A method for the automated application of a friction-modifying coating to the surface of a substrate of which it is desirable to modify the friction coefficient, the method comprising steps of: applying a binder from a series of mobile platforms to the surface of said substrate; and applying a friction-modifying filler from said series of mobile platforms to the binder.

55. The method according to claim 54 wherein said series of mobile platforms comprises at least a first mobile platform for performing the step of applying the binder and at least a second mobile platform for performing the step of applying the filler.

56. A system for the automated application of a friction-modifying coating, the system comprising: a vehicle; at least one binder storage vessel positioned on the vehicle; at least one binder pump positioned on the vehicle and coupled to the at least one binder; at least one binder application nozzle coupled to the at least one binder pump; at least one filler hopper coupled to the at least one binder application nozzle; and at least one filler metering device coupled to the at least one binder.

57. The system according to claim 56 wherein said vehicle is at least one of a truck and a trailer.

58. A system comprising: one or more pressurized binder component storage vessels positioned on a mobile platform; and one or more binder control valves coupled to said one or more pressurized binder component storage vessels to control conveyance of the binder from said one or more pressurized binder storage vessels.

59. The system according to claim 58 further comprising motorized mixers interposed between said one or more pressurized binder storage vessels and said one or more binder control valves for mixing said binder.

60. The system according to claim 58 further comprising spray nozzles or extruders coupled to the application nozzles for controlling the application of binder from the nozzles.

61. The system according to claim 58, wherein said mobile platform comprises a truck, and said system further comprises: one or more binder pumps coupled to said one or more pressurized binder storage vessels; one or more binder mixers coupled to said one or more mixers; one or more binder application nozzles coupled to said one or more binder mixers; one or more filler hoppers positioned on said truck; and one or more filler metering devices coupled to said one or more filler hoppers.

62. A method for the application of friction-modifying coatings to the surface of a substrate of which it is desirable to modify the friction coefficient, the method comprising steps of: mixing at least two of a binder, a filler and other additives; metering the binder into an applicator system; and applying the binder from a mobile platform to the surface of the substrate.