Patent Publication Number: US-2012023850-A1

Title: Method of Manufacturing Terrazzo Tiles, Terrazzo Tiles and Flooring System Assembled with Terrazzo Tiles

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 12/059,531, entitled “Method of Manufacturing Terrazzo Tiles, Terrazzo Tiles and Flooring System Assembled with Terrazzo Tiles” filed on Mar. 31, 2008, the application of which claims priority to related U.S. Provisional Application Ser. No. 60/920,667, entitled “Method of Manufacturing Terrazzo Tiles, Terrazzo Tiles and Flooring System Assembled with Terrazzo Tiles” filed Mar. 29, 2007, the disclosures of which are specifically incorporated in there entirety by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a method of manufacturing resin (terrazzo) tiles which are polished to a smooth surface, and to tiles made in that manner. More specifically, the invention also relates to a flooring system using such tiles which will add an appearance and functionality similar to poured in place terrazzo floors. 
     2. Discussion of Existing Systems 
     In the past, for most commercial applications, the flooring of choice is what is known as a terrazzo floor. Such floors typically are monolithic floors, i.e., a single surface with no breaks, which are poured in place over a substrate floor surface such as a concrete surface. The manufacture of such floors is well known and dates back for decades. 
     Typically, in the manufacture of such floors, a concrete surface is prepared and smoothed and then a resin and stone chips are mixed in with a curing agent. The resultant mixture is poured over the entire concrete subsurface. Skilled craftsmen then work the poured surface, much as skilled craftsmen work poured concrete floors in order to ensure a smooth, flat, and uniform surface for the poured terrazzo floor. Thereafter, the floor is allowed to cure and prepared for use. One desirable aspect of terrazzo floors is that the designer can obtain exactly the color desired by selection of an appropriate coloring agent or dye (pigment), and the poured in place floor is “monolithic,” i.e., does not have separate and discontinuous sealing inherent between tiles in a tile system. 
     A problem with poured in place floors, however, is that it is labor intensive and requires highly skilled craftsmen. The poured in place floors hinders adjacent construction and prolongs clean up from the floor finishing process. More specifically, while smoothing of poured concrete is a relatively simple task because the surface need not be particularly smooth, this is not the case with poured in place floors because they are generally used in high human traffic areas and are required to provide an aesthetically pleasing environment. Thus, the skill level of craftsmen working on poured in place floors needs to be very high, and the process is labor intensive, thereby resulting in a relatively high cost. 
     Past attempts to replace poured in place floors with tile systems have resulted in numerous attempts to manufacture terrazzo floor tile, but all resulted in thick and uneven tiles, and there was no way to provide a monolithic surface with such tiles as is possible with poured in place floors. 
     Accordingly, the problems of the prior art described with poured in place floors and the attempted substitute with terrazzo tiles are avoided in accordance with the invention which is described in greater detail further herein. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with the invention, in one aspect, there is provided a method of manufacturing terrazzo tiles for assembly into a floor, having characteristics similar to poured in place terrazzo floors. The method includes the steps of mixing a resin, filler, catalyst and a selected color dye or pigment in an amount sufficient to form a curable composition. The curable composition is poured into a mold, or a plurality of molds, in an amount sufficient to allow adding of stone chips, in an amount of such that the mold does not overflow. Stone chips are then poured into the mold so as to have a greater amount of stone chips settle toward the bottom of the mold in the composition than toward the top, to thereby form a composition and stone chip mixture therein. The composition and stone chip mixture is cured to form a rough tile. The tile is then ground and polished to result in a polished tile in which the upper surface of the tile is the side toward which the greater amount of stone chips settled. Typically, the composition is made up of five components. A first component is a flexible polyester resin. 
     Other components include coarse calcium carbonate filler and fine calcium carbonate filler. A pigment or dye is added for color and a catalyst is added as a hardener. 
     These components are mixed and poured into the mold, and the stone chips, typically marble chips and/or glass chips, are then poured into the mold. 
     In the case of preparing a grout for pouring into grout lines between assembled tiles on a flooring system, the flexible polyester resin, course calcium carbonate filler, fine calcium carbonate filler, pigment and optionally terrazzo chips are mixed at a factory and shipped to the job site. The catalyst is then added and the grout injected into grout lines with a caulking gun or grout bag. 
     In a more specific aspect, the molds are no more than about ⅜ inch deep. Preferably, the tiles are polished by being conveyed on a conveyer means having sidewalls to limit side to side movement of the tiles to ensure the entire top surface is polished. Polishing bricks of sequentially finer grade are arranged in sequence to polish the tiles, with all bricks bearing on each tile at all times during polishing to allow polishing of tiles of a depth of as small as about ⅛ inch without damage thereto. The constant contact avoids “buckling.” 
     In another aspect, the invention is related to terrazzo tiles made according to the method described herein. 
     In a still further aspect, the invention relates to a terrazzo floor system. The floor system includes a plurality of tiles manufactured according to the method described herein and assembled to both a solid floor subsurface or surface and a wall subsurface or surface, and spaced sufficiently from each other to define grout lines. A floor to wall transition member having a vertical extension and a horizontal extension is provided with the vertical extension and the horizontal extension connected by a curved transition section. The transition member is made flexible and of the same cured resin matrix as that of the tiles, but “tweaked” in a manner well known to be more flexible than the tiles. The transition member is adhered to a wall surface and floor surface in a manner defining a grout line between tiles adhered to the floor surface and the horizontal extension thereof, and tiles adhered to the wall surface and the vertical extension thereof. Each grout line is filled with a cured resin, or alternatively with a mix of cured resin and terrazzo chips. The cured resin is essentially the same as the cured resin matrix of the tiles. The cured resign or cured resign mixed with terrazzo chips is filled in the grout line in a manner flush with the tiles and with the vertical and horizontal extensions of the transition member to result in a floor to wall tile system which is sealed against penetration by materials spilled thereon. 
     In a more specific aspect, the vertical extension and horizontal extension of the transition member are both of the same depth as the tiles to be coextensive therewith. 
    
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
       Having thus briefly described the invention, the same will become better understood from the following detailed discussion, made with reference to the appended drawing in which: 
         FIG. 1  is a schematic diagram showing how the components for making tiles are mixed and poured into molds, and cured to result in rough tiles used in the manufacturing polished tiles in accordance with the invention; 
         FIG. 2  is a schematic diagram showing how rough tiles in accordance with the invention are ground on both sides; 
         FIG. 3  illustrates a method and polishing system for the rough ground tiles resulting from the method and system of  FIG. 2 ; 
         FIG. 4  is a greater detail view from the top of  FIG. 3  showing two sequential polishing stations, shown partially in phantom, illustrating how polishing is conducted on the tiles manufactured by the method; 
         FIGS. 5A and 5B  illustrate in partial side cross section views two alternative embodiments of how tiles are adhered to a flooring subsurface, with grout applied thereon, and showing how the grout is made flush with the tile surface; 
         FIGS. 6A and 6  B illustrate in side and front views respectively the floor to wall transition member; and 
         FIG. 7  illustrates a floor and wall system in accordance with the invention showing the corner transition between floor and wall with the floor to wall transition member shown assembled with the tiles. 
     
    
    
     DETAILED DISCUSSION OF THE INVENTION 
     In accordance with the invention there is provided a new flooring system that combines the best features of competing floor systems. More specifically, the floor system in accordance with the invention provides the advantages of a tile system combined with the advantages of a poured in place terrazzo system. Previously, it was also known to manufacture terrazzo tiles, but the processes were inconsistent, and then the resulting product could not provide the flexibility in terms of surface quality, as well as color selection that poured in place tiles provided. In accordance with the invention there is provided a method of manufacturing terrazzo tiles, tiles manufactured in accordance with the method, and flooring systems assembled with such tiles which provides a monolithic flooring system and wall system which is sealed and prevents penetration through the floor and wall system into the underlying surfaces by materials spilled on the tiles on the floor and wall. In addition, the expense of having skilled craftsmen and the required transport of large amounts of materials to the work site to assemble a poured in place floor is avoided. Tile terrazzo tiles have never completely replaced poured in place floors for two fundamental reasons. With poured in place floors, the designer can obtain exactly the colors they want, and a poured in place floor is monolithic. 
     In accordance with the invention, terrazzo tiles can be manufactured in a mass produced manner and later assembled into a monolithic floor/wall system with the color desired by the designer. More specifically, the tiles in accordance with the invention are typically standard 2 foot by 2 foot or 2 foot by 4 foot tiles, which are assembled at a factory and shipped to a job site. The tiles are installed on a floor using standard adhesives by local flooring contractors that normally install vinyl tile. During installation, the tiles are spaced about 1/16 inch to about a 1/32 inch for a resin only grout line, or about a ¼ inch to about a ½ inch for a resin and terrazzo chip mixture grout line. Thereafter, the tiles are rolled and the adhesive hardened. The grout lines are overfilled with a resin compound or a resign and terrazzo chip mixture, wherein the resin (in either instance) may be the same resin compound that is used to bind stone chips, typically marble or glass chips, into a tile. During assembly, as the grout starts to harden, the overfill is “skived” or cut off the top of the tile with a sharp scraping knife. An alternative to an overflow arrangement is the overflow controlled arrangement of  FIG. 5(   b ) which shows a dam construction which can be used to standardize the shape and amount of overflow occurring. 
     When a system in accordance with the invention is assembled, it can provide a highly sanitary floor that is watertight up the wall to a height of at least six inches to several feet. Such a system is particularly useful in operating room applications in which a constant problem is foreign substances penetrating through the existing flooring system into the sheet rock and studs making up the room, and resulting in cultivation of bacteria and other harmful organisms thereby resulting in an unsafe operating room environment. 
     Having thus generally described the invention, the following discussion is made with reference to the drawings. 
     In  FIG. 1 , a mixing system  11  includes a resin dispenser  13 , catalyst dispenser  15 , and pigment or dye dispenser  17 , which are arranged to feed the components thereof in a predetermined amount well known to those of ordinary skill in the art into a mixer and mix dispenser  19 . This mixing system  11  also includes a conveyer system  25  having molds  23  passed underneath the mix dispenser  19  from which the resulting composition is poured through a funnel  21  into molds  23 . As will become more readily apparent, it is important that these molds be no more than about ⅜ inch in depth and the amount of composition dispensed thereinto is such as to allow sufficient marble chips to be dispensed later so that the mold does not overflow. 
     Thereafter, a stone chip dispenser  27 , typically for dispensing marble chips, is arranged for pouring marble chips through a chute  29  into the mold  23  which is filled with the composition. The stone chips are dispersed uniformly over the composition surface. As a result of a uniform dispersal of stone chips from the chute  29 , a greater amount of stone chips settle in the composition towards the bottom of the mold  23  at what will eventually be the top surface of the tile, than at the upper portion of the composition. Thereafter, the molds  23  with the composition and marble chip mixture therein are passed as shown by arrow A into a curing chamber  31  which is heated. As curing occurs, a vent  33  allows noxious gases to be exhausted to atmosphere or other appropriate controlled area as shown by arrow B. 
     As shown in  FIG. 2 , after the resultant tiles  24  are cured, they are very rough on both surfaces and are passed to a grinding station  21  in which the tiles  24  are passed by a conveyer system  25  to grinder  27  having grinding elements  29  for engagement of the tiles  24  on both surfaces thereof. The tiles  24  exit as shown by arrow C to be passed to a polishing station  32 . 
     As shown in  FIG. 3 , the tiles  24 , which have now been ground, are placed on a conveyer assembly  35  with the top surface  34  facing upward. This top surface  34  is what originally appeared to be the bottom surface and is the area wherein most or the greater amount, of the stone chips settled when the stone chips were poured into the resin composition. A series of polishing stations  39 ,  41 , and  43  with increasingly finer polishing bricks  45  are assembled to polish the top surface  34  of the tiles  23 . The conveyer assembly  35  also includes a side edge  37  which is raised to prevent the tiles from slipping side to side as shown, with only two polishing stations  39  and  41  shown in  FIG. 4 . 
     The tiles  24  are conveyed to be polished by polishing bricks  45 , and as may be appreciated, side edges  37  prevent the tiles  24  from moving from side to side. The polishing bricks  45  which also function as hold down devices  45  are arranged from station to station so as to always be in contact with the tiles  24  and the upper surface  34  thereof. As a result, each tile  24  transitions, for example, from polishing station  39  to polishing station  41 , in a manner engaged by the polishing brick/hold down devices  45  of a first polishing station  39 , and then simultaneously during the transition, engaged by the hold down devices  45  of polishing station  41 , so that a set of polishing bricks/hold down devices is always in contact with the tile  24  during the polishing operation. This continuous contact with the polishing brick/hold down devices  45  is critical because it allows manufacture of tiles of thinness in depth previously thought not possible. There is also a pneumatic back pressure regulator to decrease the polishing head/hold down-device weight that is exerted onto the tile surface. 
     More specifically, in accordance with the system and polishing method of the invention, tiles can be made of a thickness of about ⅛ inch to about 3/16 of an inch. Further, by depositing the stone chips in a manner described, only the exposed surface of the tiles when assembled as a floor shows a predominance of stone chips. If polishing is not done in accordance with the method described herein, conventionally manufactured terrazzo tiles tend to buckle and break and need to be made substantially thicker. Thus, by providing a system and method which allows manufacture of tiles of a thickness previously unheard of, substantial amounts of materials can be saved resulting in significantly lower costs to the installer and end user. 
       FIG. 5A  illustrates how the floors in accordance with the invention are assembled. The tiles  24  are adhered to a floor subsurface  44 , with the top surface  34  of each tile having the greatest amount of stones facing upwards. This is the polished surface. In one embodiment of a flooring system  42 , grout  46  (which may be resin only or a resign and terrazzo chip mixture), is poured into grout lines which are typically about 1/16 inch to about 1/32 inch in width for a resin only grout line, or about a ¼ inch to about a ½ inch for a resin and terrazzo chip mixture grout line. The grout  45  is poured in a manner that a top portion  47  extends above the tile surface  34 . A skiving tool  49 , is used before the grout fully cures to cut off the upper portion  47 . Thereafter, a final polishing of the entire floor surface is conducted to result in a monolithic surface. 
     In an alternative embodiment as shown in  FIG. 5B , paper or cardboard dams  51  are assembled so that the overflow of grout results in an upper portion  47  of uniform size which can be simply broken off. Thereafter final polishing is conducted as before. 
     In order to provide a sealed tile and floor system in accordance with the invention, a floor to wall transition member  61  can be manufactured. The transition member  61  can be manufactured in a conventional mold of the same resin as the tiles, but may be without stones, and includes a vertical extension  63  and a horizontal extension  67 , with a curved transition region  65  to transition between wall and floor. This is shown in  FIGS. 6A and 6B . 
     As further shown in  FIG. 7 , the transition member  61  is assembled in contact with the wall and floor subsurface. The tiles are then adhered to the wall and floor subsurface as shown in  FIG. 7  with spacing for grout  46 , and the grout can be added as previously described. The composition of the transition member  61  is “tweaked” in a manner well known to result in a transition member  61  which is flexible as compared to the tiles  24 . 
     Having thus generally described the invention, the same will become better understood from the appended drawings in which are set forth in a non limiting manner.