Patent Publication Number: US-2013251901-A1

Title: Apparatus and Method for Coating Particulate Material

Description:
RELATED APPLICATION 
     The present application claims the benefit of the filing of U.S. Provisional Application No. 61/615,574, filed Mar. 26, 2012. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure relates to an apparatus and a method for coating a particulate material. The apparatus and the method may each in one form be applied to the coloring of particulate materials for use as a fill for artificial turf. 
     BACKGROUND OF THE INVENTION 
     Athletic fields, such as football fields, soccer pitches, track, running tracks, playgrounds, “mini-golf” areas and other recreational fields are often covered in either natural turf (e.g., sod grass) or artificial turf. Artificial turf usually has a blade or projected fiber construction and often is supplemented by the addition of a base layer of ground cover that is interspersed or embedded among the blades or fibers. In the case of an athletic field, this base layer is capable of absorbing the energy of impact of feet or other body parts making contact with the turf surface. These ground covers may include any number of types and sizes of particulate material, with examples including sand, rubber or rubberized materials. For aesthetic reasons, it may be desirable for the supporting particulate material to be colored green to mimic the look of natural turf, or may be otherwise colored to create a desired appearance. 
     In other circumstances, a particulate material may be used as an independent ground cover or surface material. Such ground cover materials may be selected from a variety of particulates, including, sand, rubber or rubberized materials, pebbles, wood or other mulch materials, etc. Again, for aesthetic reasons, it may be desirable for the material to be colored to mimic the look of natural material or may be otherwise colored to create a desired appearance. 
     If the selected material is a rubber, the ground cover material may be made of chunk or crumb sized particles. Such materials may be derived from the recycling of automotive and truck scrap tires. For example, in the case of crumb rubber, it may be prepared by removing the steel and fluff portions, leaving the tire rubber with a particulate consistency. The rubber may be further processed with a granulator and/or cracker mill to reduce the size of the particles. Different sized particles may be used depending on the end application. Chunk rubber is typically larger than ½ inch in diameter or along one side, while crumb rubber is typically smaller than ⅜ inch. Other forms and dimensions are possible. 
     The presently contemplated particulate materials have in some circumstances been found to contain metals or other materials that may leach into the surrounding environment and/or emit volatile organic compounds (VOCs). The potential long term effects on the environment and/or the individuals who come in contact with these potentially dangerous or toxic materials have recently become a concern. An environmentally friendly, green-colored coating for application to artificial turf or other substrates that serves as a barrier to VOCs and metal leachates is described in Oien et al, US 2011/0086228; the disclosure therein being herein incorporated by reference. 
     Apparatus and methods for coating landscaping materials and particulate ground cover materials are known. Winistorfer et al, U.S. Pat. No. 6,551,401, shows and describes a machine for coloring landscaping materials, such as wood mulch and the like. The apparatus in this Winistopher et al patent may be used for continuous mixing of the colorant with the mulch material within a multistage mixing bowl. The disclosure in this prior patent is also incorporated herein by reference. 
     Greenberg et al, U.S. Pat. No. 5,910,514, describes a colored rubber material formed to simulate wood mulch. Rondy, U.S. Pat. No. 5,192,587, describes the use of a continuous auger screw within an angled trough for applying colorant to a wood mulch material. Other apparatus and methods are known for coating of materials, including wood mulch and rubber particulate material. Various methods may be performed as a continuous process or on a batch basis. 
     SUMMARY OF THE INVENTION 
     The present disclosure relates to an apparatus and a method for coating a particulate material. A mixer defines a mixing chamber and receives a particulate material. An agitator includes a plurality of arms projecting radially outward from the shaft and a plurality of paddle blades positioned on the ends of the arms. The blades are formed such that the particulate material in the mixing chamber is directed in a rotational direction, a radially inward direction and an axial direction within the mixing chamber. A material feed system is provided for delivering a first coating material into the mixing chamber during rotation of the agitator, a polymer material during mixing of the coated particulate material and a reaction material for causing a reaction between the colorant feed and the polymer feed for creating a coated particulate material. 
     in a further aspect of the present disclosure is defined by a mixer having a defined mixing chamber. Means is provided for directing a quantity of particulate material into the mixing chamber. An agitator is provided in the mixing chamber having a shaft mounted for rotation, a plurality of arms projecting radially outward from the shaft, and a plurality of paddle blades. The blades are positioned on the ends of the projecting arms and are formed such that during rotation of the shaft the particulate material is directed in a rotational direction, a radially inward direction and an axial direction within the mixing chamber. A material feed system is provided and communicates with the mixing chamber. The feed system includes a coating feed for delivery of a first coating material into the mixing chamber during rotation of the agitator and mixing by the rotating paddle blades. A polymer feed is provided for delivery of a polymer material into the mixing chamber during rotation of the agitator and mixing of the coated particulate material. A reaction material is provided for causing a chemical drying reaction between the colorant feed and the polymer feed and for creating a coated particulate material. Means is further provided for discharging the encapsulated particulate material from the mixing chamber. 
     In a further aspect of the apparatus the coating feed and the reaction feed may be combined so as to deliver the first coating material and a reaction material in to the mixing chamber at the same time. 
     In a further aspect of the apparatus the plurality of agitator blades may be directed at varying angles with respect to the agitator shaft. Further, the agitator blades may be positioned at multiple radial positions relative to the agitator shaft. 
     In a further aspect of the apparatus, the polymer feed material may comprise a polyurethane pre-polymer. Further, the reaction material may comprise a catalyst for reacting with the polymer material to create the chemical drying. 
     In a further aspect of the apparatus, the mixing chamber may be defined by an elongated mixer bowl having a longitudinal axis and at least a portion of an inside surface if the bowl defining a cylindrical surface surrounding the axis. Further, the shaft of the agitator may be aligned along the axis of the bowl and at least a portion of the blades are positioned adjacent the inside surface of the bowl and rotated in a closely spaced relationship with the inside bowl wall. 
     In a further aspect of the present disclosure a method of coating a particulate material includes the steps of providing a mixing chamber; feeding a particulate material into the mixing chamber; agitating the particulate material within the mixing chamber; mixing the first coating material with the particulate feed material to create a first coating on the particulate; mixing a reaction catalyst with the coated particulate material; and mixing a pre-polymer material with the catalyst and the coated particulate material. The catalyst and pre-polymer of the method are selected to form a reaction to create chemical drying of the mixed first coating, catalyst and pre-polymer and to form a polyurethane coating that encapsulates the particulate material. 
     In a further aspect of the method, the mixing of the reaction catalyst with the first coating material may occur prior to the mixing of the first coating material with the particulate material. Further an additional reaction catalyst may be provided while mixing the pre-polymer material with the coated particulate material. 
     In a further aspect of the method, the agitating of the particulate material and the mixing of the first coating material with the particulate material may be performed by a plurality of agitator blades rotating within the mixing chamber. Further, the agitator blades may be directed at varying angles with respect to a rotating agitator shaft. The agitator blades may be positioned at multiple radial positions relative to the agitator shaft. 
     In a further aspect of the method, the mixing chamber may be defined by an elongated mixer bowl having a longitudinal axis and at least a portion of an inside surface if the bowl defining a cylindrical surface surrounding the axis. Further, the shaft of the agitator may be aligned along the axis of the mixer bowl. In addition, at least a portion of the blades may be positioned adjacent the inside surface of the bowl and are rotated in a closely spaced relationship with the inside bowl wall. 
     Other features of the present invention and combinations of features will become apparent from the detailed description to follow, taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For the purpose of illustrating the invention, the drawings show forms that are presently preferred. It should be understood that the invention is not limited to the precise arrangements and instrumentalities shown in the drawings. 
         FIG. 1  shows an embodiment of an apparatus for performing a method contemplated by the present disclosure. 
         FIG. 2  shows a mixing bowl portion of the apparatus of  FIG. 1 , with certain structures removed for illustration purposes, and the mixing bowl being shown in a feed position. 
         FIG. 3  shows the mixing bowl portion of the apparatus of  FIGS. 1 and 2 , with the mixing bowl being shown in a mixing position. 
         FIG. 4  shows the mixing bowl portion of the apparatus of  FIGS. 1-3 , with the mixing bowl being shown in a discharge position. 
         FIG. 5  shows the mixing bowl portion of the apparatus of  FIGS. 1-4 , with the mixing bowl being shown in an inspection position. 
         FIG. 6  shows a side elevation view of a positional break for the mixing bowl portion of the apparatus of  FIG. 1 . 
         FIG. 7  shows a front elevation view and partial angled view of the positional break portion of  FIG. 6 . 
         FIG. 8  shows a side elevation view of the mixing bowl portion of the apparatus of  FIG. 1 , with the mixing bowl being shown in the mixing position of  FIG. 3 . 
         FIG. 9  shows a top plan view of the mixing bowl cover plate and its associated plenum structures. 
         FIG. 10A  shows a side view of the cover plate of  FIG. 9  in the closed position relative to the mixing bowl opening. 
         FIG. 10B  shows a side view of the cover plate of  FIG. 9  in the open position relative to the mixing bowl opening. 
         FIG. 11  shows an angled view of the mixing bowl of the apparatus of  FIG. 1 , with certain internal structures shown in phantom. 
         FIG. 12  shows an alternate angled view of the mixing bowl of the apparatus of  FIG. 1 , with certain internal structures shown in phantom. 
         FIG. 13  shows a front elevation view of the mixing bowl portion of the apparatus of  FIG. 1 , with certain internal structures shown in phantom. 
     
    
    
     DETAILED DESCRIPTION 
     In the figures, where like numerals identify like elements, there is shown an embodiment of various machinery for performing a process for mixing particulate material with a coating, preferably including a colorant. The mixing apparatus is designated generally by the numeral  10  in  FIG. 1  and, as illustrated, is defined as a batch mixer. The mixer  10  is preceded by feed means  12  for delivering raw particulate material to the mixer  10 . A coating feed means  18  also communicates with the mixer  10  and directs the constituent parts of the coating to the particulate material within the mixer  10 . A discharge means  14  is provided downstream of the mixer  10  to move the coated particulate material away from the mixer  10  and direct it for further processing. The discharge means  14  is shown as depositing the finished product into a pile  16  for initial storage prior to packaging or other distribution. Other processing steps, packaging operations or storage methods may be utilized or added, as desired. 
     In the feed means  12  of the machinery, the particulate feed  20  is initially directed into a surge hopper  22 . The feed  20  may include any number of materials, such as sand, wood mulch, chipped or crumb rubber or plastic materials. The feed  20  may be loaded into the surge hopper  22  in any number of ways. It is contemplated that the particulate feed  20  will be stored in bulk and loaded, such as by a front end loader (not shown), into the top of the surge hopper  22 . The surge hopper  22  may include a number of means for spreading and controlling the flow of particulate. A conveyor structure  24  is shown in the base of the surge hopper  22  to direct the particulate to a discharge opening  26  at one end of the hopper  22 . The conveyor end  28  extends past the discharge opening  26  and moved the particulate onto the base  32  of an angled feed conveyor  30 . The discharge opening  26  may be opened and closed to control the flow of particulate feed from the surge hopper  22  to the angled conveyor  30 . The angled conveyor  30  moves the feed material from the surge hopper  22  to the mixer  10 . The base  32  of the angled conveyor  30  is positioned relatively below the top  34  of the conveyor  30 . The top end  34  of the conveyor is positioned adjacent a mixer opening  36 , when the mixer  10  is in the feed position, as shown in  FIG. 2 . 
     The bowl  38  is illustrated in  FIGS. 2-5  in various rotated positions about its central axis. Means is provided for causing rotation of the bowl  38 . Means is further provided for fixing the position of the bowl within the operative positions. These means for positioning the bowl are discussed further below. In  FIG. 2 , the feed position of the mixer  10  is shown. The mixer bowl  38  is shown in partial cross section with the bowl opening  36  positioned adjacent the top  34  of the angled conveyor  24 . The opening  36  defines a feed means for the mixer and communicates with the interior of the bowl  38 . The bowl  38  defines a mixing chamber that is generally cylindrical. An agitator  40  is provided at the center of the bowl  38  and aligns along the longitudinal axis of the bowl. As shown, the agitator  40  includes both inside agitator blades  42  and outside agitator blades  44 , each operating at different radial positions within the bowl  38 . A separate rotation means for the agitator is provided on the mixer  10  and is discussed further below. A cover plate  46  is provided adjacent the bowl  38  and is movable into and out of an engagement position. In  FIG. 2 , the cover plate  46  is shown in a non-engaged position as represented by the arrow  50 . The cover plate  46  includes a plurality of feed manifolds  48  for directing coating materials or drying gas into the bowl. 
     In  FIG. 3 , the mixer  10  is shown in the mixing position, with the mixer opening  36  rotated away from the feed position ( FIG. 2 ) and engaged with the cover plate  46 . The mixer bowl  38  is rotated about its axis and held in the mixing position and the cover plate  46  is moved into engagement as illustrated by arrow  52 . 
     In  FIG. 4 , the mixer  10  is shown in the discharge position, with the mixer opening  36  rotated to the bottom and open to the discharge means  14 . In this position, the rotation of the bowl  38 , the rotation of the agitator  40  and position of the bowl  38  define a discharge means for the mixer. The cover plate  46  is shown in the out-of-engagement position, as represented by the arrow  50 . The discharge means  14  is shown as being a second angled conveyor  60 , with the base  54  being provided below the bowl  38 . The processed particulate is directed from the bowl  38 , through the mixer opening  36  and into the receiving hopper  56  at the base  54  of the conveyor  60 . A shield  58  is provided above the hopper  56  and adjacent the outside surface of the bowl  38 . As the mixer opening  36  moves (counterclockwise) from the mixing position ( FIG. 3 ) to the discharge position ( FIG. 4 ), the shield  58  may loose catch material projected out of the opening  36  during bowl rotation. The shield  58  directs the loose material downwardly into the hopper  56 . The discharge conveyor  60  angles upwardly from the base  54 . 
     In  FIG. 5 , the mixer  10  is shown in the inspection position, with the bowl  38  rotated adjacent an inspection station  62 . The cover plate  46  is shown in the out-of-engagement position as represented by arrow  50 . The inspection position provides access to the interior of the bowl  38 , including the agitator  40  and its blades  42 ,  44 . 
     In  FIGS. 6 and 7 , there is shown a means  64  for fixing the rotated position of the mixer bowl  38 . The fixing means  64  generally comprises a brake  66  that engages a flange  68  fixed to the outside surface of the bowl  38 . The brake  66  is composed of a caliper  70  having a u-shaped channel  72  therein with brake pads  74  positioned on opposing sides of the channel  72 , with the bowl flange  68  positioned between the pads  74 . A hydraulic piston  76  feeds fluid to the caliper  72  to control activation of the brake pads  74  into engagement with the bowl flange  68 . An activation lever  78  is provided on the piston apparatus  72  for manual control of engagement of the pads  74  with the flange  68 . One source for dual disk brakes of the type illustrated is Tolomatic, Inc. of Hamel, Minn. A system controller  80  (see  FIG. 1 ) may also be programmed to activate the brake  66 . In operation, the fixing means  64  is engaged upon setting the desired position of the bowl  38  (see  FIGS. 2-5 ) to fix the bowl  38  in it operative position. 
     A bowl drive motor  82  is shown in  FIG. 8  and is connected to the bowl  38  via a connecting shaft  86  (see  FIG. 13 ). The bowl drive  82  is used to rotate the bowl  38  to the various operative positions ( FIGS. 2-5 ). A separate agitator drive motor  88  (see  FIG. 13 ) is provided to rotate the agitator shaft  90  and the connected agitator  40 . As shown, the mixing of the particulate feed and the coating materials is performed while the bowl  38  is stationary (i.e., not rotating), as set by the fixing means  64 . The system controller  80  and appropriate sensors (not shown) are used to identify the rotated position of the bowl  38 . The controller  80  may set the bowl drive  82  to rotate the bowl  38  a fixed amount. The controller  80  may also control the fixing means  64  during rotation of the bowl or the fixing means  64  may serve solely to lock the bowl  38  once it reached the desired position. The bowl drive motor  82  is contemplated to be smaller in size than the agitator drive  88 . For example, a 2 HP motor for rotation, of the bowl to its desired operational positions may be sufficient, while a 50 HP motor may be required for agitator rotation. It is noted that rotation of the agitator  40  may occur during rotation of the bowl  38  by means of drive  82 . When the bowl includes particulate material and/or coating chemicals therein, the rotation of the agitator will assist in rotation of the bowl. The bowl drive  82  and agitator drive  88  are contemplated to operate in either rotational direction. Although the bowl  38  may be permitted to rotate a full 360 degrees, it is contemplated that rotation would occur only between the end points of the missing position ( FIG. 3 ) and the inspection position ( FIG. 5 ), while passing through the feed position ( FIG. 2 ) and the discharge position ( FIG. 4 ). A gear reduction and torque arms are also contemplated for efficient operation of the mixer  10 . Other drive forms are possible including the use of a chain drive and/or shifting transmissions. 
     In  FIG. 8 , the mixer  10  is shown mounted on a base frame  92 , which surrounds the discharge conveyor base  54  and the receiving hopper  56 . A support frame  94  is positioned on the base frame  92  and supports the mixer bowl  38  and associated hardware, including the bowl drive  82  (and the agitator drive  88  as shown in  FIG. 13 ). The brake  66  is fixed to the support frame  94  and the bowl shaft  86  is supported by bearings  84  at each end (see also  FIG. 13 ). As shown in  FIG. 8 , the bowl  38  is rotated to the mixing position, as is also shown in cross section in  FIG. 3 , with the opening  36  closed by the cover plate  46 . As indicated by arrow  52 , the cover plate is moved to the engagement position. 
     Details of the cover plate  46  are shown in  FIG. 9 , which is a top plan view of the cover plate  46  showing means for feeding various components of the coating materials into the mixer bowl  38 . Various feed manifolds  48  are positioned on the cover plate  46 . Three liquid manifolds  48 A,  48 B,  48 C are designated for directing various coating materials into the bowl, when the plate  46  is engaged with the bowl opening  36  (see  FIGS. 3 and 8 ). 
     As shown, manifold  48 A is provided to direct the polyurethane pre-polymer into the bowl. The manifold is formed by a plurality of nozzles  128  provided a spaced positions along the length of the cover plate  46  (and, thus, the length of the bowl). In  FIG. 9 , eight nozzles are shown, with each being fed from a common valve assembly  130 . The valve assemble  130  is provided to control the recirculation of the pre-polymer material during other operational steps. The valve assembly  130  is normally open, preventing the pre-polymer material from being directed into the nozzles  128 . However, a certain pumping force is provide to maintain a flow of material from the valve  130  to a return line  132 , which is directed back to the storage means  122  ( FIG. 1 ). The feed line  134  also connects the storage means  122  to the valve assembly  130 . When the valve  130  is closed, pre-polymer material flows to the nozzles and is sprayed into the bowl  38 . The nozzles for feed of the pre-polymer material may be ¼ inch SCP valve nozzles from Adhesive Systems Technology Corp of Minneapolis, Minn. Such nozzles may have an auto closing feature and may further be sealed by a grease packing material during shut down of the mixer. 
     The second manifold  48 B is designated for introducing the first coating material or colorant into the mixer bowl. As shown, two nozzles  136  are provided from directing liquid into the bowl  38 . The nozzles are connected to a feed pipe  138 , which is feed from the colorant storage means  126  ( FIG. 1 ). As discussed further herein, it is contemplated that the flow of the first coating material into the bowl  38  may be at a relatively high rate and does not create by itself a buildup problem upon introduction into the mix. 
     The third manifold  48 C is provided for introduction of a reaction means or catalyst into the bowl to assist in the curing process for the colorant and pre-polymer materials. The catalyst flow is directed into the bowls through nozzles  140 , which are fed by feed line  142  that in turn communicates with storage means  124  ( FIG. 1 ). Additional feed lines are shown. These feed lines may be provided for directing water into the bowl  38  or an additional gas into the bowl or to assist in the flow of the liquid material through the nozzles. For example, forced air may be used to actuate the pre-polymer nozzles  128  and/or the catalyst nozzles  140 . 
     Openings  48 D are provided in the cover plate for directing gas into or withdrawing gas out of the bowl  38 . As shown, the gas blower  96  (See  FIG. 8 ) is connected to the cover plate  46  at an opening  48 D on one side of the cover plate  46 . The blower serves to input gas into the bowl during the drying step, or otherwise, while the opposite side openings  48 D serve as a gas exhaust. Flexible hosing is provided between the blower  96  (see, e.g., hose  106  in  FIG. 8 ) and its mounting position on the opening  48 D on the cover plate  46 . Other flexible connections (not shown) may connect the coating feed means  18  and the various manifolds  48 A,  48 B,  48 C to allow from movement of the cover plate  46 . 
     In  FIGS. 10A and 10B , there is shown the movement of the cover plate  46  into and out of engagement with the mixer bowl  30 . In  FIG. 10A , the bowl  38  is provided in the mixing position, with the bowl opening  36  adjacent the cover plate  46 . The cover plate is brought into engagement with the opening  36  as represented by arrow  52 . Movement of the cover plate  46  is created by pistons  98  (see also  FIG. 9 ) connected by linkage  100  to the plate  46 . The pistons are supported on a cover frame  102 , which is supported on the bowl support frame  94  (see  FIG. 13 ). The cover plate is further supported on linear tracks  104 , to control travel of the plate  46 . In  FIG. 10B , the cover plate is disengaged from the opening  36  of the mixer bowl  38  as represented by arrow  50 . The shafts of pistons  98  extend outward to drive the linkage  100  and the plate  46  away from the bowl  38 . As shown, the blower  96  is connected to the plate by hose  106 , which flexes to allow for relative movement of the plate with respect to the blower  96 . Similar flexible connections are made with the manifolds  48 A,  48 B,  48 C and the coating feed means ( 18 ). Once the cover plate  46  is separated from the opening  36 , the mixer bowl may rotate about its axis to another operational position (as shown by, e.g.,  FIGS. 2-5 ). 
       FIGS. 11 and 12  show various external and internal structures of the mixer  10 . The bowl  38  includes a hollow, cylindrical body  110  and two end plates  112 ,  114 . The bowl opening  36  is defined by a projecting rim  116 . The agitator  40  is supported within the center of the bowl body  110 , with agitator shaft  118  positioned along the axis of the bowl  38 . The shaft  118  extends outwardly from both end plates  112 ,  114 . One end of the shaft is connected to the agitator drive  88 , positioned adjacent the end plate  114 . The other shaft end projects from the end plate  112  adjacent the bowl drive  82 . As shown in  FIG. 13 , bearings  84  support the ends of the agitator shaft  118 . Multiple bearings are contemplated to be included to support both the agitator  88  and the bowl shaft  86 . As also shown in  FIG. 13 , the brake flange  68  for the fixing means  64  and its associated caliper  70  are provided on end plate  114 , although the flange may be provided on the opposing end plate or a fixing mean of another form may be provided for holding the bowl in a desired rotated position. 
     As shown in  FIGS. 8 and 13 , the bowl support frame  94  is mounted on the base frame  92 . A plurality of load cells  120  are provided under the posts of bowl frame  94  and are supported by the adjacent portions of the base frame  92 . The load cells serve to measure the weight of the bowl  38  and its contents for purposes of controlling the particulate feed and the coating process. The load cells  120  are connected to the system controller  80 , which in turn controls the operation of the particulate feed means  12 , rotation of the agitator  40 , position of the mixer bowl  38 , the addition of coating materials through the manifolds  48 , the discharge means  16 , etc. The load cells may take the form of model WM-II (No. 70210) as sold by Artech Industries, Inc. (Riverside, Calif.). These specific load cells are designed for double ended beams in tank weighing. Other weight measuring devices may be utilized. 
     In operation, the feed particulate material  20  is loaded into the surge hopper  22 , while its conveyor  24  is running. The internal structures of the surge hopper  22  and its metering means at the discharge opening  26  direct a relatively controlled flow of particulate onto the angled conveyor  30 . The angled conveyor  30  moves the particulate feed to the bowl  38  and directs the feed into the bowl opening  36 , which is set in the feed position of  FIG. 2 . The load cells  120  serve to measure the weight of the particulate within the bowl  38 . Upon reaching a predetermined load, the system controller  80  turns off the conveyor  24  in the surge hopper  22  and the angled conveyor  30 . Hence, the feed into the bowl  38  is stopped. A signal is sent to the brake  66 , such that the caliper  70  releases from engagement of the bowl disk  68 . A further signal from the system controller  80  causes the bowl drive motor  82  rotated the bowl  38  from the feed position of  FIG. 2  to the mixing position of  FIG. 3 . A further signal directs the cover plate  46  into engagement (arrow  52 ,  FIG. 10B ) with the bowl opening  36 . The agitator  40  may be rotated at various times and speeds to assist in the feed and bowl rotation. For example, it is contemplated that rotation of the agitator during the particulate feed will assist in effective distribution of particulate material throughout the bowl and in effect speed up the feed portion of the process. 
     When the bowl  38  is ready ( FIG. 3 ) for mixing of the particulate material with the coating chemicals, the load cells  120  may again be utilized to measure the quantities of the coating chemicals, and the like, added to the bowl  38 . The coating feed means  18  includes one or more pumps that are controlled by the system controller SO, which in turn responds to signals generated by the load cells  120 . 
     A plurality of storage means  122 ,  124 ,  126  (see  FIG. 1 ) are provided for retaining constituent parts of the coating to be applied to the particulate retained with in the mixer bowl  38 . The controller  80  starts a pump that feeds coating chemicals from one or more of the storage means  122 ,  124 ,  126  into a correspond manifold  48 A,  48 B,  48 C on the cover plate  46  (see  FIG. 9 ). A diaphragm pump is contemplated for directing the coating chemicals from storage to the bowl. The cut off signal from the controller  80  may take into account the typical amount of continued flow of material from the manifold after the pump is stopped. Hence, the control signal may take into account the actual measured weight determined from the four load cell signals and the predicted flow after pump stop in fixing the desired amount of the coating chemical introduced into the bowl. A more detailed description of coating materials and processes, useful with the apparatus herein described, are provided below. 
     The agitator  40  as shown in various figures includes a series of inside blades  42  rotating at an inner radius position within the mixer bowl  38  and a series of outside blades  44  rotating at an outer radius position relatively close to the inside surface of the bowl  38 . The blades  42 ,  44  are attached to a common shaft  90  positioned co-axial with the bowl axis. Each of the blades has a paddle portion positioned on the projected end of a blade shaft. The blade shafts include a kink or bend at about their midsection. The paddle ends include a relatively broad face and an outer lip. The kink in the blade shaft and the form of the paddle end are intended to create a lifting of the particulate material within the bowl. The blades  42 ,  44  are located at various positions along the length of the shaft  90  within the mixer bowl  38  (see, e.g.,  FIGS. 11-13 ). The kink in the blade shaft and the lip on the paddle portions serve to create a radially inward or lifting movement to the particulate. Further, the paddle ends are directed a various axial angles to move the particulate in multiple axial directions within the bowl. The two blade series  42 ,  44  serve to agitate the particulate material at multiple levels to provide a better mixing action. The position of the outside blades  44  is contemplated to pass along the linear length of the entire cylindrical surface of the bowl  38 . 
     The form of the agitator blades  42 ,  44  is contemplated to impart rotational motion to the particulate. In addition, the agitator blades impart a motion to the particulate in directions both parallel (axial) and perpendicular (radial) relative to the shaft  90  of the agitator  40 . At relatively higher rotational speeds, a scrubbing or rubbing action for the particulate and coating chemicals may be created, assisting in the mixing of the coating materials. Other blade styles and agitator forms may also be used along with the contemplated coating process and coating materials. The agitator  40  is contemplated to be made of steel and be coated or otherwise formed to resist adherence of the coating chemicals. The blade shafts and agitator shaft are welded together with a high degree of finishing of the joints being provided. 
     A liner may be included in the bowl for protection of the bowl wall and to make the mixer resistant to buildup of coating material. The liner may be a single sheet of material that is formed or positioned into engagement with the bowl wall. Brackets may be provided at the mixer opening  36  to secure the one piece liner to the inside surface of the bowl. Clearance is provided between the liner and the agitator blades  44 , which are the blades positioned closest to the bowl wall. End liners may also be fastened on to the end plates  112 ,  114 . These end liners may have a single piece construction or may be assembled from multiple parts. Fasteners are contemplated to secure the end liners to the end plates. The fasteners preferably are countersunk into the material of the end liners (or the bowl liner) to provide a relatively smooth interior surface. One possible liner material may be ultra-high-molecular-weight polyethylene (UHMW). 
     A variety of sensors may be included in the mixer  10  and the other components that serve to control overall operation, preferably through a programmable logic controller (PLC) or similar device within the system controller  80 . For example, sensors may be provided to continuously determine the rotational position of the agitator shaft  90  with logic to determine the position of the paddles relative to the manifolds  48  on the cover plate  46 . Because of the potential adhesive nature of some materials that may be used in coating the particulate, it may be advantageous to sequence the fluid delivery (by means of a spray, jet, etc.) into the mixer bowl  38  and to discontinued delivery at the time when the paddle portions of the agitator blades  42 ,  44  are in proximity to the nozzle outlets of the manifolds  48  on the cover plate  46 . Proximity sensors may be utilized separately or in conjunction with the positional locators for the rotation of the agitator shaft. The sensors signals serve to cut off flow through the nozzles (or the like) approximately  2  times per revolution. This nozzle control may be applied at all times during the coating process or may occur only when adding certain materials which may cause adhesion to the agitator blades (or similar structures). 
     As discussed in more detail below, a polyurethane pre-polymer material may be used in the coating process contemplated. The nozzles ( 128 , see  FIG. 9 ) for directing this material into the mixer bowl  38  from the manifold ( 48 A, see  FIG. 9 ) on the cover plate  46  may be standard polyurethane nozzles of the type without an included needle valve at the output end. Such nozzles forms are defined by a nozzle opening having a specific length and width. The polyurethane pre-polymer material will typically not “drip” from the nozzle, depending on viscosity. 
     It is contemplated that the coating feed means  18  may include heating means to control the temperature of the pre-polymer (or other) coating chemicals during processing, where control of the viscosity, temperature or other characteristic of the material is desired. The heating means may take the form of a heating blanket wrapped around the storage container for the pre-polymer material. Such a blanket may be a Powerblanket® product as sold by Powerblanket, LLC of Salt Lake City, Utah. In use, the pre-polymer material has been found to have acceptable flow characteristics when maintained at a temperature of 90 degrees Fahrenheit, although other temperatures and conditions may be applied and found acceptable. 
     Further, the feed of pre-polymer (or other coating chemicals) may be defined by a closed loop, where a certain pressure is required for the material to be directed into the nozzle portion of the manifold. The material will be directed into a return loop and feed back into the storage means  122 ,  124  or  126 , unless the valve is closed. The heating may be a heating blanket wrapped around one of the storage means containing the pre-polymer. A nitrogen gas may be directed into the storage means to seal the material in an uncured state during periods between coating operations. The material may also cure at the nozzle ( 128 ,  FIG. 9 ) to temporarily seal the nozzle during operation. Pressure from the feed pump to the fees line ( 134 ,  FIG. 9 ) may also be used to purge the temporary seal. A sealing grease or petroleum jelly may be applied to the nozzles to maintain the feed lines closed for longer periods, such as while the mixer is out of use. 
     As shown in  FIG. 1 , the discharge means  14  deposits the finished product into a pile  16  for initial storage. This bulk storage may be included as part of an additional packaging and distribution system. For example, the discharge means may direct the coated particulate material to a bagging operation, including a metering of the finished product into the associate bag or package. The packages may have any desired size or configuration. Larger “bulk” storage sacks, capable of handling weight loads in the range of 1000 lbs. to 2000 lbs, which may then be supported on a shipping pallet, are presently considered economical. Alternatively, the finished product may be loaded, by front end loader or the like, into a truck and delivered in a relatively large volume. Again, other processing steps, packaging operations or storage methods may be utilized or added, as desired. The form of storage and packaging may dictate adjustments within the coating process so as to maintain the finished product in a relatively loose, particulate form, without the need for further processing to separate product that has adhered together during storage or packaging. 
     The coating processes as contemplated for use with the apparatus described above generally contemplates the coating of a particulate material while generally maintaining the particle size of the feed material within the final product. Further, a colorant may be added to the coating for adaptation of the particulate product to specific applications. In one specific example, the coating may be used for coloring crumb rubber particles for use as a filler material for artificial turf fields. 
     In one example, the coating is applied to the particulate in two or more stages. The first stage in this example includes a green color and the second stage coating is a topcoat of polyurethane. The green coating is preferably opaque, to hide the raw color of the crumb rubber. Preferably, the topcoat material is based on polyurethane pre-polymer based on methylene diphenyl diisocyanate (MDI), which uses moisture available from the first stage chemicals to initiate a curing or drying reaction. The polyurethane pre-polymer is combined with a reactive material or catalyst that creates a chemical reaction, drying the coating materials and encapsulating the particles. 
     The overall coating process of the present example may typically involve a number of steps, including the two stage application of the chemicals. First, the crumb rubber particulate material is loaded into a mixer, such as the mixing apparatus  10  as discussed above. The mixer  10  receives the particulate based on weight, which is generally associated with a desired volume of material in the mixing bowl. The batch weight of the particulate is determined within the mixer  10  by means of the four load cells  120  provided on the base of the support frame  94 . The load cells generate signals that are calibrated by the system controller  80  to a weight of the material added to the bowl  38 . It is contemplated that up to about 60% of the bowl volume is occupied by the particulate during processing of a single batch. The agitator  40  moves the particulate material within the bowl  30 , while a quantity of the first stage coating chemicals is added. Again, measurement of the first stage coating chemicals is contemplated to be based on weight, determined by the load cells  120 . A contemplated range for the weight of the first stage colorant, in the contemplated example, is 1% to 5% by weight of the colorant to the rubber particulate. 
     Mixing of the first stage materials and the particulate occurs for a defined period of time, contemplated to be in the rage of about 1 to 10 minutes. Upon completion of the mixing step, a specific weight of the second stage, polyurethane pre-polymer, in the range of 1% to 8% by weight of the second stage material to the existing materials (first stage chemical and the particulate combined). At the time the second stage chemicals are added, the first stage chemicals are coated on the particulate and are still in a relatively wet condition. Again, the mixer  10  proceeds to agitate the materials in the bowl as the second stage material is added. The agitation serves to add a further coating onto the particulate and uniformly spread the second stage coating throughout the mixer bowl  38 . The chemical reaction, described in further detail below, between the first and second stage causes the color and the topcoat to dry, encapsulating the underlying particulate. The reactive catalyst may be provided as part of the first stage coating material or may be added to the pre-polymer material within the both. Once the drying process has completed to a desired extent, the mixer bowl  38  may be rotated to the discharge position ( FIG. 4 ) and the coated/encapsulated particulate is removed by the discharge means, and the discharge conveyor moves the material away from the mixer for further processing. 
     As discussed above, one example the first stage coating material is contemplated to be an opaque (hiding) green color coat. A general formula for this first stage coating may be defined as follows: 
     
       
         
           
               
               
               
             
               
                   
                   
               
             
            
               
                   
                 Water 
                 10-20% 
               
               
                   
                 Dispersant 
                  1-10% 
               
               
                   
                 Defoamer 
                 0.1-1%   
               
               
                   
                 pH control agent 
                 0.1-1%   
               
               
                   
                 Yellow Oxide Pigment 
                 25-50% 
               
               
                   
                 Titanium Dioxide 
                  1-10% 
               
               
                   
                 Phthalo Green Pigment 
                  2-10% 
               
               
                   
                 Rheology Modifier 
                 0.1-2%   
               
               
                   
                 Catalyst 
                 1-8% 
               
               
                   
                 Resin Solution 
                  2-12% 
               
               
                   
                   
               
            
           
         
       
     
     The elements within the above general formula are provided for various purposes. For example, the dispersant is provided to aid in separation and suspension of the pigments and to provide stability such that the pigments do not settle and remain suspended. The purpose of the defoamer is to reduce the amount of foam generated during the pigment dispersion step and mixing. The pH control agent also aids in the pigment dispersion and in conjunction with rheology modifier provides viscosity stability within the finished product. The resin solution has the purpose of aiding the grinding of the pigment; that is, to reduce the particle size in order to develop the color within mixture. The yellow oxide pigment, titanium dioxide and phthalo green pigment provided to create the desired color (within the green example). The purpose of the catalyst is described above. 
     In addition to the above defined elements, a water based acrylic polymer may optionally be included in the color coat at levels from 5 to 20% (by weight). This acrylic polymer is intended to improve adhesion of the color to the particulate material, particularly to crumb rubber. 
     The second stage coating is contemplated in the present example to be polyurethane pre-polymer. The polyurethane pre-polymer is added to create a polyurethane topcoat that encapsulates the underlying particulate and colorant. Further, the combination of the pre-polymer and the reactive catalyst creates a chemical “drying” or curing that is sufficient to continue the coated material in a particulate form after mixing is complete. 
     Polyurethanes are in the class of compounds called reaction polymers. A urethane linkage is produced by reacting an isocyanate group, —N═C═O with alcohol (hydroxyl group: OH). Polyurethanes are generally produced by the polyaddition reaction of a polyisocyanate with a polyalcohol (polyol), often in the presence of catalyst(s) and other additives. When polyols are reacted with a molar excess of a polyisocyanate, the resultant product (pre-polymer) contains urethane linkages and isocyanate end groups—the latter of which will further react upon mixture with any molecule containing active hydrogen such as additional polyols or water. 
     The pre-polymer contemplated for the second stage additive to the present process example is intended to be reacted with ambient water within the first stage materials to form the final coating and is generally referred to as moisture curing polyurethane. Such moisture curing polyurethane pre-polymers will react with themselves, through the isocyanate groups, in the presence of moisture in the air. This moisture curing reaction can be accelerated by the addition of catalyst(s). The moisture curing reaction proceeds when isocyanate groups react with water, forming an amine with carbon dioxide being released. The resulting amine reacts with an additional isocyanate to form urea linkages. The polyurea functionality may, in turn, react with additional isocyanate groups to form a crosslinking branched network. 
     The curing process creates chemical bonds called “crosslink sites” throughout the coating matrix. The crosslink site density is affected by the polyurethane pre-polymer isocyanate functionality, the polyol selected in the preparation of the pre-polymer, and the catalyst used. The two main classes of catalyst that typically used are organometallics and amines. Organometallics are generally used to accelerate the reaction and formation of urethane linkages. Amines can promote the formation of urethane linkage, and are often used as well to promote the crosslinking through the moisture cure reaction, in essence creating a chemical drying. 
     Stability prior to application of the polyurethane pre-polymer is typically important to the contemplated process. The polyurethane pre-polymer is maintained in an inert environment that is free of moisture, since atmospheric moisture may start the crosslinking reaction. Polyurethane pre-polymers are generally packaged in tightly closed containers with a nitrogen blanket to remove trace amounts of air-borne moisture before sealing the package. If catalyst is present in the polyurethane pre-polymer and moisture is available the package stability may be lost. At the time of application of the coating to the particulate, the speed of the curing of the top coat may be an important factor for operational efficiencies. A catalyst may be used to promote the speed of curing process. 
     In the present example, the catalyst is provided in the (waterborne) latex color coating. This eliminates the step of handling and adding the catalyst separately. The polyurethane pre-polymer is introduced to the water and catalyst at the same time in a two step application process. Hence, in the first stage, the color coat containing water and catalyst is applied to the particulate substrate, followed by the addition of the polyurethane pre-polymer while first stage coating is still “wet”. A water stable 2,2-dimorpholinodiethylether amine or other catalyst in the same family is provided in the first stage color coating. The catalyst creates a curing mechanism and is separately added and thus promotes curing at the application stage, without risk to shelf life stability of the polyurethane pre-polymer. As the polyurethane pre-polymer is spread across the colored rubber particulate substrate, it comes into contact with the water and catalyst, and thus promoting fast and efficient curing. 
     As a variant to the overall process, the coating chemical may be applied in segregated, sub-stage amounts. As one example, a portion of the added water in the first stage may be added separately from the other chemical components. Hence, the curing process may be further controlled by a separate introduction of the water to the mixture. Additional drying may be created by forced air or other gases. In the mixing apparatus  10  as shown, the gases may be introduced into the bowl  38  through the blower  96 , which is connected to openings within the cover plate  46  by the flexible hose  106 . 
     In the following examples, a green-colored coating is provided on a rubber particulate material and mixed in a designated manner. The examples vary between the use of a chunk rubber particulate and a rubber particulate falling within the crumb rubber size designation. In each example, a mixing device essentially was utilized within the apparatus as shown and described herein to prepare the finished product. 
     EXAMPLE 1 
     Green Color Coating for Chunk Rubber 
     In the present example, the components of Tables 1 and 2 are combined to create a first coating material that is mixed according to the process described. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Chemical 
                   
                 Weight 
               
               
                 Material Type 
                 Name 
                 Supplier (Location) 
                 % 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Water 
                 — 
                 — 
                 46.16 
               
               
                 Resin Solution 
                 Joncryl 678 
                 BASF Corp (New 
                 8.85 
               
               
                   
                   
                 Jersey) 
               
               
                 Defoamer 
                 DEE FO 3030 
                 Munzing Co. (New 
                 0.10 
               
               
                   
                   
                 Jersey) 
               
               
                 Colorant - Yellow 
                 Chemik CB313 
                 Chemik Co. Ltd. (China; 
                 33.52 
               
               
                 Iron Oxide 
                   
                 other distributor: Royale 
               
               
                   
                   
                 Pigments, (New Jersey)) 
               
               
                 Colorant - Titanium 
                 Ti-Pure ® 
                 DuPont Co. (Delaware) 
                 3.93 
               
               
                 Dioxide 
                 R-706 
               
               
                   
               
            
           
         
       
     
     The components of Table 1 are blended in a laboratory by combining the chemicals together for about 30 minutes at a blending rate of 1600 revolutions per minute (RPM). The blended combination is then placed at rest (0 RPM) for a period of about 2 minutes. The components shown in Table 2 are then added and blended for about 10 minutes at a rate of 300 RPM. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                   
                 Chemical 
                   
                   
               
               
                 Material Type 
                 Name 
                 Supplier (Location) 
                 Weight % 
               
               
                   
               
             
            
               
                 Defoamer 
                 DEE FO 3030 
                 Munzing Co. (New 
                 0.10 
               
               
                   
                   
                 Jersey) 
               
               
                 Modifier 
                 Rheolate ® 1 
                 Elementis Specialties, 
                 0.27 
               
               
                   
                   
                 Inc. (New Jersey) 
               
               
                 Catalyst 
                 KA4 
                 ITWC, Inc. (Iowa) 
                 1.00 
               
               
                 Colorant - Phthalo 
                 DG008-356 
                 Spectra Colorants 
                 6.07 
               
               
                 Green Pigment 
                   
                 (South Carolina) 
               
               
                   
               
            
           
         
       
     
     In the coating process, the mixer  10  is run with the internal agitator  40  rotating and the rubber particulate fee directed into the mixer bowl  38 . The rate of rotation of the agitator  40  is set at a loading speed of about 15 RPM. The mixer bowl  38  is filled with 2,000 pounds (lbs) of chunk rubber as determined by the load cells  120 . The rate of feed into the mixer  10  is relatively fast and is contemplated to take a total time of about 1 minute. 
     The mixer  10  in the present example is sized in the present example whereby the particulate load occupies about half of the internal volume of the bowl. This general volume range is considered advantageous for exposing the surface area of the particles during mixing. Using this range, a large mixer would be provided to batch process a greater load of particulate. As a further example, the mixer handling a 2000 lbs load of rubber may have a bowl with an internal volume of about 160 cubic feet. A mixer handling a load of rubber of 4000 lbs may have a volume of about 320 cubic feet. As discussed in other examples below, a mixer handling a batch load of 20 lbs may have a bowl volume of about 1.5 cubic feet. These volumetric numbers are provided as illustrative examples and are not considered limiting on the form of the mixer. Moreover, linear scaling of bowl volume is again not a specific requirement, but illustrative of preferred construction. 
     Upon determination of the desired load of rubber particulate by the load cells  120 , the mixer bowl  38  is moved (rotated) from the feed position ( FIG. 2 ) to the mixing position ( FIG. 3 ) with the cover plate  46  engaged (arrow  52 ) over the opening  36 . The rotation of the agitator  40  is adjusted to a color addition speed of about 10 RPM. The colorant material for the first coating in the formulas of Tables 1 and 2 is pumped into the mixer bowl  38  through one or more manifolds  48 , with the load cells  120  measuring the total weight added to the bowl  38 . For the batch prepared in the current example, 20 lbs of the first coating is added, which is 1% of the weight of the rubber particulate in the batch. The rate of pumping of the first coating into the bowl  38  is relatively quick, resulted in a total pumping time of about 30 seconds. The rubber and first coating material is then mixed by the agitator  40  with in the mixer bowl  38  for about 1 minute. 
     The addition of the second coating material, which is the pre-polymer, the mixer speed is set to an addition speed of about 10 RPM. The pre-polymer utilized in the present example is Lupranate 5080 obtained from BASF (New Jersey). The total weight of the coating materials in this example is 26 lbs. Hence, the total weight of the pre-polymer coating is 1.3% of the weight of the rubber material. The total pumping time to add the second coating pre-polymer to the mixer bowl  38  is about 90 seconds. After mixing the pre-polymer with the coated particle, a further quantity of the catalyst is added. This additional catalyst in the present example is about 3% of the weight of the first coating. (The particular KA4 catalyst provided is a 2,2, Dimorpholinodiethylether material.) The coated rubber, including the first coating, the pre-polymer and the additional catalyst is mixed until dry-to-touch, which occurred in about 22 minutes. It is contemplated that the final mixing time may range between about 15 to 30 minutes depending on color, catalyst amount, temperature and other ambient conditions. The “dry-to-touch” test in the present examples is performed by observing that there is no color transfer to a gloved hand when inserted into the mixture in the bowl (with the agitator not rotating, for safety concerns). 
     The addition of catalyst may be adjusted to control the overall reaction. It has been found that the addition of too much catalyst may result in a reduction of the durability of the coating, causing flaking or chipping of the coating. It is generally believed that this durability reaction is the result of a curing process that is too fast. Alternatively, too little catalyst may extraordinarily extend the curing time or result in the coating taking on an adhesive quality, creating conglomeration of the particulate. An additional factor in the process may also be the form and speed of the mixer. 
     Upon determining desired dryness in the Example 1, the agitator  40  within the mixer bowl  38  is adjusted to the discharge speed of about 15 RPM. The coated product is then discharged from bowl  38  ( FIG. 4 ), taking about 3 to 5 minutes, including an inspection to make sure all project had been discharged. At this point, the product is moved away from the mixer  10  by the discharge conveyor  14 . Upon full discharge, the mixer bowl  38  may be rotated back to the feed position ( FIG. 2 ) and made ready for preparation of the next batch of feed material. 
     EXAMPLE 2 
     Green Color Coating for Crumb Rubber 
     The components of Tables 3 and 4 are combined in this example to create a first coating that is blended according to the process as described. In the prior example, the particulate is chunk rubber. In the current example, the particulate is smaller is size and falls within the classification of crumb rubber. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 3 
               
               
                   
               
               
                   
                 Chemical 
                   
                   
               
               
                 Material Type 
                 Name 
                 Supplier (Location) 
                 Weight % 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Water 
                 — 
                 — 
                 25.00 
               
               
                 Resin Solution 
                 Joncryl 678 
                 BASF (New Jersey) 
                 4.54 
               
               
                 Dispersant 
                 Tamol 731A 
                 Dow Chemical 
                 0.40 
               
               
                   
                   
                 (Michigan) 
               
               
                 pH Modifier 
                 MIPA (mono 
                 Dow Chemical 
                 1.14 
               
               
                   
                 isopropanol 
                 (Michigan) 
               
               
                   
                 amine) 
               
               
                 Water 
                 — 
                 — 
                 1.14 
               
               
                 Defoamer 
                 DEE FO 47J 
                 Munzing Co. New 
                 0.02 
               
               
                   
                   
                 Jersey) 
               
               
                 Colorant - Yellow 
                 Chemik CB313 
                 Chemik Co. Ltd. (China; 
                 34.09 
               
               
                 Iron Oxide 
                   
                 other distributor: Royale 
               
               
                   
                   
                 Pigments, (New Jersey)) 
               
               
                 Colorant - Clay 
                 ASP ® 172 
                 BASF (New Jersey) 
                 17.05 
               
               
                 Pigment 
               
               
                   
               
            
           
         
       
     
     The coating components of Table 3 are prepared in a laboratory by combining the materials together for about 2 minutes at a blending rate of 500 RPM. The materials identified in Table 4 are then added to the combination and blended for about 30 minutes at a rate of 1400 RPM. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 4 
               
               
                   
               
               
                 Material Type 
                 Chemical Name 
                 Supplier (Location) 
                 Weight % 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Water 
                 — 
                 — 
                 13.60 
               
               
                 Colorant - Phthalo 
                 GN7 
                 Spectra Colorants 
                 3.00 
               
               
                 Green Pigment 
                   
                 (South Carolina) 
               
               
                 Defoamer 
                 DEE FO 3030 
                 Munzing Co. (New 
                 0.02 
               
               
                   
                   
                 Jersey) 
               
               
                   
               
            
           
         
       
     
     In process, the internal agitator  40  is rotated at about 15 RPM within the mixer bowl  38 . During the rotation, the bowl  38  is filled with 2,000 lbs of crumb rubber. The rate of feed into the mixer  10  results in a total feed time of about 45 seconds. Upon determination of the desired load of rubber particulate by the load cells  120 , the mixer bowl  38  is rotated from the feed position ( FIG. 2 ) to the mixing position ( FIG. 3 ). The agitator  40  is then increased in speed to about 30 RPM. The first coat material resulting from the chemicals within Tables 3 and 4 is pumped into the mixer bowl  38  through manifolds  48 , with the load cells  120  measuring the total weight added. In the current example, the first coat materials added is 40 lbs (or 2% of the weight of the rubber particulate). The pumping rate for the first coat material into the bowl  38  may occur is approximately 1 minute. The rubber and first coating material are then mixed within the bowl  38  for at least 1 minute to ensure proper coating of the particulate. 
     During the addition of the second coating, or pre-polymer, material, the mixer speed is set to about 10 RPM. The pre-polymer in the present example is QPZ 14, supplied by ITWC Inc. of Malcolm, Iowa. The total weight of coating materials added is 60 lbs (or about 3.0% of the weight of the rubber material). The total pumping time to add the second coating to the mixer bowl  38  is about 3 minutes. A catalyst is then added to the mixture. The catalyst in the present example is KA4 (from ITWC Inc. of Malcolm, Iowa). The total catalyst added is 1.6 lbs (or about 4% of the weight of the first coat material). 
     The rubber, first coating, pre-polymer material and catalyst is mixed in the mixer bowl  38  by the agitator  40  until dry-to-touch (as herein discussed), which may occur in about 25 minutes. Again, the final mixing time typically may range between about 20 to 30 minutes, depending on color, catalyst amount and temperature conditions. 
     Upon determining the desired dryness, the agitator  40  within the mixer bowl  38  is adjusted to the discharge speed of about 15 RPM. The coated product is then discharged from bowl  38  ( FIG. 4 ) in about 2 to 3 minutes, including an inspection to make sure the entire product is discharged. The product is moved away from the mixer  10  by the conveyor. Upon full discharge, the mixer bowl  38  may again be rotated back to the feed position, ready for preparation of the next batch. 
     EXAMPLE 3 
     Green Color Coating for Crumb Rubber 
     The components of Tables 5, 6 and 7 were combined to create a first coating that is mixed with a crumb rubber particulate in the process described. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 5 
               
               
                   
               
               
                 Material Type 
                 Chemical Name 
                 Supplier (Location) 
                 Weight % 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Water 
                 — 
                 — 
                 17.30 
               
               
                 Resin Solution 
                 Joncryl 678 
                 BASF Corp. (New 
                 8.86 
               
               
                   
                   
                 Jersey) 
               
               
                 Dispersant 
                 Tamol 731A 
                 Dow Chemical 
                 0.29 
               
               
                   
                   
                 (Michigan) 
               
               
                 pH Modifier 
                 MIPA 
                 Dow Chemical 
                 0.77 
               
               
                   
                   
                 (Michigan) 
               
               
                 Defoamer 
                 DEE FO 3030 
                 Munzing Co. (New 
                 0.05 
               
               
                   
                   
                 Jersey) 
               
               
                   
               
            
           
         
       
     
     The coating components of Table 5 are prepared by combining the materials together for about 5 minutes at a blending rate of 600 RPM. The materials identified in Table 6 are then added to the combination and blended for about 30 minutes at a rate of 1400 RPM. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 6 
               
               
                   
               
               
                   
                 Chemical 
                   
                   
               
               
                 Material Type 
                 Name 
                 Supplier (Location) 
                 Weight % 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Colorant - Yellow 
                 Chemik 
                 Chemik Co. Ltd. (China; 
                 40.10 
               
               
                 Iron Oxide 
                 CB313 
                 other distributor: Royale 
               
               
                   
                   
                 Pigments, (New Jersey)) 
               
               
                 Colorant - Titanium 
                 Ti-Pure ® 
                 DuPont Co. (Delaware) 
                 4.82 
               
               
                 Dioxide 
                 R-706 
               
               
                   
               
            
           
         
       
     
     Prior to the addition of the materials identified in Table 7, the blending speed is reduced to about 600 RPM. The components of Table 7 are added to the mixture and blended for about 10 minutes at a rate of 600 RPM. The resulting combination may then be used as the first coat colorant for the crumb rubber particulate. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 7 
               
               
                   
               
               
                   
                 Chemical 
                   
                   
               
               
                 Material Type 
                 Name 
                 Supplier (Location) 
                 Weight % 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Acrylic Polymer 
                 Fulatex ® 
                 HB Fuller (Minnesota) 
                 19.28 
               
               
                 Colorant - 
                 PD-3802 GN7 
                 Spectra Colorants 
                 8.19 
               
               
                 Phthalo Green 
                   
                 (South Carolina) 
               
               
                 Pigment 
               
               
                 Modifier 
                 Rheolate ® 1 
                 Elementis Specialties, 
                 0.48 
               
               
                 (thickener) 
                   
                 Inc. (New Jersey) 
               
               
                 Defoamer 
                 DEE FO 3030 
                 Munzing Co. (New 
                 0.05 
               
               
                   
                   
                 Jersey) 
               
               
                 Catalyst 
                 KA4 
                 ITWC, Inc. (Iowa) 
                 4.82 
               
               
                   
               
            
           
         
       
     
     In process, the internal agitator  40  within the mixer  10  is rotated at about 15 RPM during receipt of the rubber particulate feed into the mixer bowl  38 . The bowl  38  is sized for receipt of 2,000 lbs of crumb rubber, which may occur in about 45 seconds. Upon completion of the desired load, the mixer bowl  38  is moved to the mixing position ( FIG. 3 ) and the agitator  40  rotated at about 30 RPM. The first coating material as defined in Tables 5, 6 and 7 is pumped into the mixer bowl  38 , with the load cells  120  measuring the total weight added. In the present example, 40 lbs of the first coating material (or 2% of the weight of the rubber particulate) is added to the bowl in approximately 1 minute. The rubber and first coating material are then mixed for at least 1 minute to fully coat the particulate. 
     During the addition of the second coating material, the agitator  40  within the mixer  10  is rotated at about 10 RPM. The second coating material or pre-polymer selected in the present example is Lupranate 5230, as supplied by BASF (New Jersey). The total weight of pre-polymer added is 60 lbs (or 3% by weight of the rubber material). The total pumping time to add the pre-polymer is contemplated to be about 3 minutes. The catalyst in the present example is included within the first coating material and is reacted with the pre-polymer during mixing. The coated rubber and second coating/pre-polymer material is mixed until dry-to-touch (as herein discussed), which typically occurs in about 25 minutes. Again, the final mixing time may range between about 20 to 30 minutes, depending on color, catalyst amount, temperature and other ambient conditions. 
     Upon determining desired dryness, the agitator  40  within the mixer bowl  38  is adjusted to the discharge speed of about 15 RPM. The coated product is discharged from bowl  38  ( FIG. 4 ) in about 3 minutes, including inspection time. The coated product is moved away from the mixer  10  and the mixer is prepared for processing a further batch. 
     The foregoing examples are defined for both chunk and crumb size rubber particles and result in an opaque green colored coating. Variations in the green color and in the opacity of the coating are possible. Other colors are also possible and are contemplated. Landscape and playground materials are known to be colored blue, yellow, green, red, silver, brown, khaki, mustard and black (among others). Chunk rubber or similar sized materials may be used in these environments, with any of the identified colors preferably applied as part of the first coating material in the process. Similar colors may be utilized to coat the crumb rubber or similar sized materials for typical applications in sports fields and playgrounds. These materials may also be fixed into mats or sheets by the additional application of an adhesive polymer to the dry (coated) particles. 
     EXAMPLE 4 
     Red Color Coating for Chunk Rubber 
     The components of Tables 8, 9 and 10 are combined to create a (brick) red coating and blended according to the process as described. In the present example, the blending is performed within a laboratory and then the resulting coating is applied in a mixer as otherwise contemplated herein. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 8 
               
               
                   
               
               
                 Material Type 
                 Chemical Name 
                 Supplier (Location) 
                 Weight % 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Water 
                 — 
                 — 
                 17.00 
               
               
                 Resin Solution 
                 Joncryl 678 
                 BASF (New Jersey) 
                 3.60 
               
               
                 pH Modifier 
                 MIPA (mono 
                 Dow Chemical 
                 0.80 
               
               
                   
                 isopropanol amine) 
                 (Michigan) 
               
               
                   
               
            
           
         
       
     
     The coating components of Table 8 are blended for about 5 minutes at a blending rate between 700 RPM. The materials identified in Table 9 are then added in the order specified and blended at the same rate for about 15 minutes. The blender speed is then increased to 900 RPM for about 45 minutes. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 9 
               
               
                   
               
               
                 Material Type 
                 Chemical Name 
                 Supplier (Location) 
                 Weight % 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Defoamer 
                 DEE FO 3030 
                 Munzing Co. (New 
                 0.01 
               
               
                   
                   
                 Jersey) 
               
               
                 Thickener 
                 Kelzan ® S 
                 CP Kelco (Oklahoma) 
                 0.29 
               
               
                   
                 Xanthan Gum 
               
               
                 Colorant - Red 
                 Chemik CB 130 
                 Chemik Co. Ltd. (China; 
                 56.00 
               
               
                 Iron Oxide 
                   
                 other distributor: Royale 
               
               
                   
                   
                 Pigments, (New Jersey)) 
               
               
                 Defoamer 
                 DEE FO 3030 
                 Munzing Co. (New 
                 0.04 
               
               
                   
                   
                 Jersey) 
               
               
                   
               
            
           
         
       
     
     The blender is stopped (0 RPM) for about 2 minutes. As indicated in Table 10, additional water is added to the combination. The blender is set to a blend rate of 300 RPM. A catalyst is then added, along with a (further) quantity of defoamer. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 10 
               
               
                   
               
               
                 Material Type 
                 Chemical Name 
                 Supplier (Location) 
                 Weight % 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Water 
                 — 
                 — 
                 19.25 
               
               
                 Defoamer 
                 DEE FO 3030 
                 Munzing Co. (New 
                 0.01 
               
               
                   
                   
                 Jersey) 
               
               
                 Catalyst 
                 KA4 
                   
                 3.00 
               
               
                   
               
            
           
         
       
     
     The total catalyst weight added is 3% of the total weight of the coating. The batch is mixed at the 300 RPM rate for about 10 minutes. The coating material is then ready for application to the chunk rubber. 
     Mixing of the chunk rubber particulate with the coating materials in the present example is performed in a mixer generally of the type shown, having lifting-type paddle blades with the mixer bowl. In the present example, the bowl is sized for 20 lbs of particulate and, as discussed above has an internal bowl volume of 1.5 cubic feet. Due to the size of the bowl and batch, a lower number of agitator blades are provided, as compared to the device illustrated in the present drawings (see, e.g.,  FIGS. 11-13 ). In the example, the mixer includes and agitator with four paddle arms with the blades on the ends of the arms positioned adjacent the bowl wall. (Hence, in the example mixer, the blades are not positioned at different radii, as in the figures.) The blades on the ends of the arms are formed an varying angles and provide a lift function to direct the material radially inward for exposing the particulate to the coating materials. 
     Chunk rubber (sized to about ¾ inch) is added to the mixer and with the agitator rotated at a speed of about 15 RPM. The first coating material according to the formula above is added to the rubber. The weight of the first coating is 1% of the weight of the rubber, or in the present batch about 2 lbs. The rubber and first coating are initially mixed for about 1 minute. The pre-polymer material is then added. The weight of the pre-polymer is 1.3% of the weight of the rubber. In the present example, the pre-polymer is 2.6 lbs of Lupranate 5080 (BASF (New Jersey)). Mixing is performed until dry-to-touch (as noted above). 
     EXAMPLE 5 
     Blue Color Coating for Chunk Rubber 
     The components of Tables 11, 12 and 13 were combined to create a blue colored coating that is blended according to the process as described. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 11 
               
               
                   
               
               
                 Material Type 
                 Chemical Name 
                 Supplier (Location) 
                 Weight % 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Water 
                 — 
                 — 
                 24.36 
               
               
                 Resin Solution 
                 Joncryl 678 
                 BASF (New Jersey) 
                 10.0 
               
               
                 Defoamer 
                 DEE FO XHD 47J 
                 Munzing Co. (New 
                 0.10 
               
               
                   
                   
                 Jersey) 
               
               
                   
               
            
           
         
       
     
     The coating components of Table 11 are combined together for about 5 minutes at a blending rate between 640 RPM. The materials identified in Table 12 are then added to the combination and blended for 30 minutes at the same rate. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 12 
               
               
                   
               
               
                 Material Type 
                 Chemical Name 
                 Supplier (Location) 
                 Weight % 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Colorant - 
                 Ti-Pure ® R-706 
                 DuPont Co. (Delaware) 
                 45.0 
               
               
                 Titanium 
               
               
                 Oxide 
               
               
                 Thickener 
                 Kelzan ® S 
                 CP Kelco (Oklahoma) 
                 0.17 
               
               
                   
                 Xanthan Gum 
               
               
                   
               
            
           
         
       
     
     The blending is stopped (0 RPM) and the components in Table 13 are added. The combination is blended for about 10 minutes at a rate of 300 RPM. The coating material is then ready for application to the chunk rubber. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 13 
               
               
                   
               
               
                 Material Type 
                 Chemical Name 
                 Supplier (Location) 
                 Weight % 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Defoamer 
                 DEE FO 3030 
                 Munzing Co. (New 
                 0.10 
               
               
                   
                   
                 Jersey) 
               
               
                 Colorant - Blue 
                 Spectra DB 153-002 
                 Spectra Colorants 
                 17.27 
               
               
                   
                   
                 (South Carolina) 
               
               
                 Catalyst 
                 KA4 
                 ITWC, Inc. (Iowa) 
                 3.00 
               
               
                   
               
            
           
         
       
     
     Mixing of the chunk rubber particulate with the coating materials in the present example is performed in a mixer generally of the type shown, having lifting-type paddle blades with the mixer bowl. Again, in the present example the bowl is sized for 20 lbs of particulate, although other size mixers are possible (as in the other examples), with scaling up of the coating materials to match the quantities of particulate to be mixed. Chunk rubber (sized to about ¾ inch) is added to the mixer and with the agitator rotated at a speed of about 15 RPM. The first coating material according to the formula above is added to the rubber. The weight of the first coating is 1% of the weight of the rubber, or in the present batch about 2 lbs. The rubber and first coating are initially mixed for about 1 minute. The pre-polymer material is then added. The weight of the pre-polymer is 1.3% of the weight of the rubber. Again, in the present example, the pre-polymer is 2.6 lbs of Lupranate 5080 (BASF (New Jersey)). Mixing is performed until dry-to-touch (as noted above). 
     EXAMPLE 6 
     Brown Color Coating for Chunk Rubber 
     The components of Tables 14, 15 and 16 are combined to create a brown colored coating and then mixed with chunk rubber particles. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 14 
               
               
                   
               
               
                 Material Type 
                 Chemical Name 
                 Supplier (Location) 
                 Weight % 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Water 
                 — 
                 — 
                 14.00 
               
               
                 Dispersant 
                 HC 850-32 
                 Harcross Chemicals, 
                 0.67 
               
               
                   
                   
                 Inc. (Kansas) 
               
               
                 pH Modifier 
                 MIPA (mono 
                 Dow Chemical 
                 0.80 
               
               
                   
                 isopropanol 
                 (Michigan) 
               
               
                   
                 amine) 
               
               
                 Colorant -- Carbon 
                 N326 
                 Sid Richardson 
                 6.31 
               
               
                 Black 
                   
                 (Texas) 
               
               
                   
               
            
           
         
       
     
     The coating components of Table 14 are combined together for about 30 minutes at a blending rate of 1400 RPM. The materials identified in Table 15 are then added with the blender continuing to run at 1400 RPM for 30 minutes. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 15 
               
               
                   
               
               
                   
                 Chemical 
                   
                   
               
               
                 Material Type 
                 Name 
                 Supplier (Location) 
                 Weight % 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Water 
                 — 
                 — 
                 5.00 
               
               
                 Resin Solution 
                 Joncryl 678 
                 BASF (New Jersey) 
                 4.00 
               
               
                 Colorant - Red Iron 
                 Chemik 
                 Chemik Co. Ltd. (China; 
                 45.75 
               
               
                 Oxide 
                 CB 130 
                 other distributor: Royale 
               
               
                   
                   
                 Pigments, (New Jersey)) 
               
               
                   
               
            
           
         
       
     
     The components of Table 16 are added after a 2 minute rest (0 RPM). The blending rate is then increased to 300 RPM for 10 minutes. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 16 
               
               
                   
               
               
                 Material Type 
                 Chemical Name 
                 Supplier (Location) 
                 Weight % 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Water 
                 — 
                 — 
                 19.50 
               
               
                 Defoamer 
                 DEE FO 3030 
                 Munzing Co. (New 
                 0.03 
               
               
                   
                   
                 Jersey) 
               
               
                 Modifier 
                 Rheolate ® 1 
                 Elementis Specialties, 
                 0.94 
               
               
                   
                   
                 Inc. (New Jersey) 
               
               
                 Catalyst 
                 KA4 
                 ITWC, Inc. (Iowa) 
                 3.00 
               
               
                   
               
            
           
         
       
     
     Mixing of the chunk rubber particulate with the coating materials in the present example is performed in a mixer having lifting-type paddle blades with the mixer bowl. In the present example the bowl is sized for 20 lbs of particulate (with scaling up of the coating materials to match the quantities of particulate to be mixed in larger mixers being possible). Chunk rubber is added to the mixer and with the agitator rotated at a speed of about 15 RPM. The first coating material according to the formula above is added to the rubber. The weight of the first coating is 1% of the weight of the rubber, or in the present batch about 2 lbs. The rubber and first coating are initially mixed for about 1 minute. The pre-polymer material is then added. The weight of the pre-polymer is 1.3% of the weight of the rubber. Again, in the present example, the pre-polymer is 2.6 lbs of Lupranate 5080 (BASF (New Jersey)). Mixing is performed until dry-to-touch (as noted above). 
     Evaluative Testing 
     Using the examples provided, further testing was performed on the durability of the coating. A test for evaluating durability is defined as follows. A 100 grams (0.22 lbs) portion of coated and cured rubber particulate is added to a 200 grams (0.44 lbs) quantity of water. The coated particulate is a placed within a 1 pint container and shaken for 5 minutes in a paint shaker-type mixing machine. The particulate is then separated from the water and the water evaluated for appearance. A rating scale is provided for the water rubbing evaluation test: 
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 Evaluation 
                 Rating 
               
               
                   
                   
               
             
            
               
                   
                 Clear water 
                 0 
               
               
                   
                 No color tint/with small particles 
                  0+ 
               
               
                   
                 Slight visible color tint 
                 1/2 
               
               
                   
                 Colored tint (varying intensity) 
                 1 to 3 
               
               
                   
                 Intensely colored and transparent 
                 4 
               
               
                   
                 Intensely colored and opaque 
                 5 
               
               
                   
                   
               
            
           
         
       
     
     In the defined test, the wet rubbing of the particulate may cause abrasion of the particles against each other and affect the coating adhesion and durability. The amount of color in the water is correlated to the abrasion resistance, with the lower rating being the more resistant the material. 
     In Table 16 there is a provided a comparative testing of the coatings of Examples 4, 5 and 6 when processed in a mixer of the type shown in the present drawings and another “standard” mixer. In the present test, the “standard” batch of coated particulate is prepared in a cement mixer having a rotating bowl with agitating vanes on the inside surface. The results of the comparison are shown. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 16 
               
               
                   
                   
               
               
                   
                   
                   
                 Mixing/Drying Time 
                 Durability 
               
               
                   
                 Color 
                 Mixer Type 
                 (minutes) 
                 Rating 
               
               
                   
                   
               
             
            
               
                   
                 Red 
                 Paddle 
                 15 
                  0+ 
               
               
                   
                 Red 
                 Standard 
                 30 
                 3 
               
               
                   
                 Blue 
                 Paddle 
                 17 
                  0+ 
               
               
                   
                 Blue 
                 Standard 
                 27 
                 4 
               
               
                   
                 Brown 
                 Paddle 
                 17 
                  0+ 
               
               
                   
                 Brown 
                 Standard 
                 25 
                 1/2 
               
               
                   
                   
               
            
           
         
       
     
     As shown, the use of a standard mixer resulted in a significant increase in the time to reach dry-to-touch (measured from the addition of the pre-polymer to the coated particulate). This comparison utilized the same formulation for the initial coating and the same quantities of particulate, coating and pre-polymer. In addition, the durability of the coating was significantly better when process in the paddle mixer as compared to the standard mixer. It is believed that the improvement is the result of the mixing operation in the paddle mixer. As contemplated by the present disclosure, the agitator is formed by a plurality of arms having an angles paddle blades, with the blades preferably having a lifting function resulting from the blade form and position. The mixer thus repeatedly exposes the surface of the particulate both to the coating materials and to the ambient environment. This paddle agitation creates a more efficient drying and further results in an increase in durability of the coating material. 
     The present disclosure includes a description and illustration of a number of exemplary embodiments. It should be understood by those skilled in the art from the foregoing that various other changes, omissions and additions may be made therein, without departing from the spirit and scope of the invention, with the invention being identified by the foregoing claims.