This invention relates generally to synthetic ground coverings.  In particular, the invention is directed to the use of rubber combined with prepolymeric binders which are used for protective ground coverings in such areas as fitness rooms, playgrounds, factories and the like. 
There are many situations in which hard flooring is not beneficial to the human body.  In areas of high traffic, hard floors can cause various ailments such as bad knees and the like.  On factory floors and other areas in which people must stand, hard floors can cause back and other problems.  In fitness rooms and physical therapy facilities, the use of hard floors is also minimized to prevent injury.  Playgrounds are a prime example of where injuries can be caused by contact with hard surfaces.  As people continue to exercise and children continue to play, the chance of injury caused by contact with a hard floor or ground surface continues to increase.  In order to minimize the risk of injury, protective ground covering has been introduced in areas such as playgrounds, weight rooms, jogging tracks, exercise rooms, factory floors, etc.  These protective floorings can come in various shapes and use various materials.  Unconsolidated loose fill materials such as sand, sawdust, and wood chips are in widespread use in several of these fall or impact zones.  Rubber flooring is another alternative to minimize impact.  The rubber flooring can be used in all of the environments described above.  Examples of such flooring for playgrounds are sold and marketed by Dodge-Regupol, Inc. under the Playbound, Playguard and FX Tile brand names.  Examples of such flooring for exercise facilities and the like include Everoll, Everlast and ECO tiles also marketed and sold by Dodge-Regupol, Inc. These floors generally consist of a top layer or wear surface and a backing layer that provides the cushioning and shock absorption characteristics required for the particular application. 
While these types of rubber floorings are effective for providing cushioning and protecting against injury from impact, current products offered in the market have various limitations.  The material and the manufacturing process used limits the applicability of the rubber flooring in various environments.  In environments in which liquids may be spilled, such as restaurants, the use of porous surfaces allows the penetration of the liquid into the tile, which can result in damage to the tile.  Therefore, it would be beneficial to provide a rubber tile and process of manufacture resulting in a tile having a top layer that is less porous.  Also, the products currently used for protective flooring are limited in their aesthetic nature by the limitation of color and patterns available.  Due to the materials used and the process of manufacture, the options relating to appearance are severely limited, thereby making the use of rubber flooring less appealing to potential customers.  It would, therefore, be advantageous to provide flooring tile in which the aesthetic nature of the product is enhanced
A protective flooring surface is disclosed which provides the protection and cushioning characteristics required, while enhancing the durability and aesthetics of the flooring.  The method of manufacturing of the flooring is also disclosed. 
A protective flooring tile is disclosed.  The protective flooring tile has a durable and water resistant prefabricated top layer which is made of rubber material.  The top layer has a top surface and a bottom surface, with the bottom surface having voids which extend from bottom surface toward the top surface.  A resilient bottom layer extends from the top surface and is made of granulated rubber.  The bottom layer has a prepolymer material provided between the granulated rubber which bonds the granulated rubber together.  The prepolymer material flows from the bottom layer into the voids of the top layer during the manufacture of the protective flooring tile to bond the top layer to the bottom layer. 
The density of the top layer of the protective flooring tile is greater than the density of the bottom layer, which allows the top layer to provide the water resistant characteristics required for harsh environments.  The prefabricated top layer may also have controlled geometric patterns provided therein. 
The invention is also directed to a method of manufacturing the protective flooring tile.  The method utilizes a molding press which has at least one mold cavity provided thereon.  The mold cavity is either preheated or heated as the material is provided therein.  Backing material is mixed and poured into the mold cavity.  The backing material is generally mixed at room temperature.  A prefabricated rubber mat is positioned in the mold cavity on top of the backing material.  The prefabricated rubber mat is dimensioned to have larger dimensions than the inside dimensions of the mold cavity, thereby allowing the rubber mat to be compression molded, which facilitates the positioning of the rubber mat on the backing material and helps to insure that the rubber mat will lay flat on the backing material to avoid air pockets forming therebetween.  Pressure is applied to the rubber mat and the backing material, causing a prepolymer material of the backing mixture to flow into voids provided on the rubber mat.  The heat and pressure are applied for a predetermined time to allow the prepolymer material to vulcanize or cure, thereby insuring that the rubber mat will permanently adhere to the backing material when the protective flooring tile is removed from the mold cavity.  Utilizing this method, the rubber mat will expand to conform to the inside dimensions of the mold cavity when the rubber mat is exposed to the heat of the mold cavity.