Patent Description:
Recyclable floor coverings include carpet, matting, wood, and tile. Carpet and matting, for example, rubber matting, typically require substantial amounts of solvents and/or adhesives during production or installation. Conventional solvents and adhesives produce emissions, which can be harmful to the environment.

Additionally, disposal of conventional carpets and matting poses difficulties inasmuch as these materials can be difficult to recycle. For example, conventional carpets and mattings are often formed of dissimilar materials, and therefore, conventional recycling techniques, which may include liquidation of the materials to be recycled, are relatively ineffective.

For example, one type of floor covering provides a flocked layer of nylon fibers electrostatically flocked onto a polyvinylchloride (PVC) backing. In production of this material, a glass fiber layer is added between a PVC backing and a flocking to provide dimensional stability. The flocked floor covering is screen printed to provide a wide range of patterns and colors. However, PVC is generally not considered to be easily recyclable. Furthermore, heating PVC, for example, in a liquidation process, produces hazardous fumes. Additionally, the need to add a glass fiber increases manufacturing complexity and cost. Furthermore, the glass fiber material itself may be difficult to recycle.

An alternative form of surface covering provides a flocked layer adhered to a substrate via an adhesive. However, as discussed above, adhesives, and any solvents associated with such adhesives, contribute to pollution in the environment surrounding the production and possibly the installation process. Additionally, the use of liquid adhesives during the production process poses difficulties in providing a uniform layer of adhesive. This lack of uniformity creates difficulties in adding a flocked layer to the backing material. Therefore, providing an attractive, preprinted flocking layer to a backing material covered in a liquid adhesive has typically been difficult.

Accordingly, a desire exists for a recyclable floor covering that is relatively free of solvents during its production process and which provides a uniform bonding layer between an upper layer, for example a flocking layer, and a lower layer, for example a backing material.

<CIT> discloses a mat with a textile surface and an elastomer backing layer that includes elastomer crumbs and a binder. The elastomer backing layer includes voids between the elastomer crumbs for increased flexibility.

<CIT> discloses carpet tiles having a tuft bind or precoat layer, such as a urethane precoat, disposed in overlying relation to a resilient backing formed from a mass, mixture, or slurry, for example, of particles or crumbs, bonded together in adjoined relation by a binder. One or more optional stabilizing and/or backing layers may be included.

The invention provides a laminated surface covering as claimed in claim <NUM>.

These an other advantages of the invention, in its various aspects, will become more apparent and more readily appreciated from the following detailed description of the exemplary embodiments of the invention taken in conjunction with the accompanying drawings where:.

With reference to <FIG>, one example of a surface covering according to the present invention is depicted in isometric view. The product <NUM> includes a layer of facing material <NUM> bonded to a layer of backing material <NUM> via a layer of bonding material <NUM>. In other words, the bonding material <NUM> is sandwiched between the facing material <NUM> and the backing material <NUM>.

In the depicted embodiment, the facing material <NUM> is a rubber material, namely EPDM (ethylene propylene diene Monomer (M-class)) rubber. The bonding material <NUM> is a heat-activated bonding material, i.e., one that is typically in solid form at room temperature <NUM>° C (<NUM>°F) and becomes much less viscous at higher temperatures, typically about <NUM> (<NUM>°F) and above. In one example, the bonding material becomes partially liquefied between about <NUM> and <NUM>. The term "about" in this document means plus or minus ten percent, when dealing with numerical values. The bonding material <NUM> is sandwiched between the facing material <NUM> and the backing material <NUM> in a process described later. One benefit of using a bonding material that is in solid or semi-solid form at room temperature such as the bonding material <NUM> is that the facing material <NUM> may be bonded to the backing material <NUM> with relatively little solvent in comparison with conventional bonding techniques used for conventional flooring materials. In one example, the bonding material <NUM> is mostly or entirely free of hydrocarbon solvents. In another example, the bonding material <NUM> is mostly or entirely free of all solvents, including organic and inorganic solvents. Additionally, the bonding material <NUM> can be disposed between the facing material <NUM> and the backing material <NUM> in a relatively uniform layer. In other words, lumps, bubbles, runs, or other irregularities that may be present when applying a typical liquid-based adhesive to a backing material can be reduced or avoided. The above-noted increase in uniformity of the bonding layer can provide an improved appearance to the finished product inasmuch as the facing material <NUM> may include a decorative pattern, and runs, bubbles, or lumps disposed in a bonding material located beneath the facing material <NUM> may detract from the appearance of the facing material <NUM>.

The backing material <NUM> is typically formed of a granulated rubber material. In other words, the granulated material is interbonded with itself via a process as described in <CIT> and <CIT>. The backing material <NUM> may further be material as described in Downey, <CIT>.

The backing material <NUM> may be produced from granulated rubber material such as recycled rubber material from discarded automobile tires, for example. Additionally, the backing material <NUM> may be formed, entirely, or partially, from material produced by recycling discarded floor coverings, for example, floor coverings using the same type of backing material as the backing material <NUM>. Thus, the costs and environmental impact of producing the backing material <NUM> may be less than conventional backing materials inasmuch as the backing material <NUM> may be produced by recycling other products (such as tires, floor matting, shoe soles or carpet) or incorporating used backing material that is identical or similar to the backing material <NUM> in composition. In one example, the product <NUM> is itself ground into particles and inter-bonded by heat fusion or a chemical bonding agent to form a new layer of backing material <NUM>. Depending on the content of the products recycled to form the backing material <NUM>, additional rubber materials such as raw rubber or substantially pure rubber may be added to form a mixture of recycled materials and raw materials. For example, the entire flooring material <NUM> may be ground to form granules. Then, depending on whether the granules formed by this process contain impurities or undesirable materials, granules formed from raw rubber material or from more pure recycled rubber may be added to create an appropriate mixture of recycled and raw materials. Pressure, a binder and/or heat may be added to the mixture to form a billet of rubber backing material with inter-bonded granules. The billet is typically cylindrical in shape and is cut, shaved, or shaped by rotating the billet while a blade is pressed against the billet to form a continuous sheet or layer of backing material <NUM>. The backing material <NUM> is then rolled into a roll inasmuch as this material is typically thin and flexible enough to bend without breaking.

In one example, the backing material <NUM> includes <NUM>% or more of granulated recycled rubber material from a flooring material such as the flooring material represented by reference numeral <NUM>. In another example, the backing material <NUM> is substantially <NUM>% recycled material from a flooring material such as the flooring material <NUM> depicted in <FIG>, or <FIG>. In other words, the entire surface covering <NUM> may be turned into a backing material <NUM> for a following generation of surface covering <NUM>.

<FIG> describes a side view of the flooring material <NUM> depicted in <FIG>. As shown in <FIG>, the backing layer <NUM> typically includes granules <NUM> interbonded with each other to form the backing material <NUM>. The granules <NUM> may be bonded to each other via partial melting with or without the addition of a binder material.

As is apparent from <FIG>, the interbonded granules <NUM> can produce a relatively uneven surface. Accordingly, application of a liquid adhesive to such a surface creates difficulties in the application of a facing material to the backing material <NUM>. This is so because the high portions and low portions of the granules <NUM>, when coated with a liquid adhesive, tend to create high spots and low spots in the adhesive layer. Accordingly, the flooring material <NUM> depicted in <FIG> is formed with a process using a bonding material that is typically in solid or semi-solid form at room temperature. Once the bonding material <NUM> is applied to either the backing material <NUM> or the facing material <NUM>, heat activates the bonding material <NUM>, and the facing material <NUM> and the backing material <NUM> are adhered to each other. The heat may be introduced to the bonding material <NUM> in the form of heat stored in at least one of the materials <NUM> and <NUM>. The heat may be applied via a lamp, for example, an infrared lamp which will be discussed later. Alternatively, or additionally, the heat may be applied to the bonding material <NUM> via a heating apparatus after the facing material <NUM> sandwiches the bonding material <NUM> with the backing material <NUM>.

<FIG> depict an enhanced facing material <NUM> disposed on the bonding material <NUM> rather than the rubber material <NUM> described in <FIG>. The enhanced may include one or more of a flocked material, a tufted material, recycled fibers, a woven fabric, a non-woven fabric, wear-layers, cotton fibers, and/or synthetic fibers. fibers which are not according to the invention. Similar processes to those described above and hereafter regarding bonding the facing material <NUM> to the backing material <NUM> are used to bond the enhanced facing material <NUM> to the backing material <NUM>. Thus, the enhanced material can be used to produce a wide range of floor coverings or carpet.

<FIG> depict a wood-grain facing material <NUM> provided on the backing material <NUM> rather than a rubber facing material <NUM> or flocked facing material <NUM>. The wood-grain facing material <NUM> is a wood-grain PVC. As discussed previously, certain recycling processes using PVC create harmful byproducts. However, as the recycling process that may be used in the formation of the backing layer <NUM> does not completely liquefy the materials used to form this layer, the backing material <NUM> may be recycled from surface covering <NUM> even if the surface covering <NUM> includes PVC in the wood-grain layer <NUM>. In other words, the recycling process used to create the backing material <NUM> can accommodate materials of different chemical compositions and of different specific gravities. In one example, the backing material can include grains of PVC material interbonded to grains of another material of a different specific gravity, such as EPDM or another type of rubber. Accordingly, it is possible to recycle the surface covering <NUM> in its entirety into a new backing layer <NUM> if the finished product is to be a second generation of the surface covering <NUM>.

<FIG> depicts a flow chart illustrating one example of the process used to produce the products described in <FIG>, and <FIG>. In step S701, a backing material is inserted in the form of a roll in a backing unwind station <NUM> (see <FIG>). The backing material may be a recycled material or a substantially new material. In any case, the backing material may be strong enough to support the weight of a person when installed on a floor surface.

Step S702 indicates that a bonding material is disposed in an unwind station. Typically, the backing material is introduced to the unwind station in the form of a roll, as is the backing material.

Similarly, a facing material is introduced into a facing material unwind station in step S703. It should be noted that, in some cases the backing material, bonding material, or facing material may be introduced in a form other than in a roll. Therefore, if the backing material, bonding material, or facing material is introduced in the form of a flat sheet or some other form different from a roll, no unwind steps such as depicted in steps S701, S702, and S703 will be necessary.

The respective materials are unwound in steps S704, S705, and S706. As the process is typically used in a commercial application, time required for the manufacture of the surface covering is a factor in determining the cost of the material. Accordingly, the backing, bonding, and facing materials used in the process typically travel within a range of approximately <NUM> to <NUM> feet per minute. Additionally, in order to maintain product flow, one batch of backing, bonding, or facing material will typically be spliced with another batch of the respective material (or roll of material) in the splice steps S708, S709, and S710.

In some cases, the ultimate surface covering produced by the process will include a flocking material that is separately applied to the facing material. This optional process is depicted in steps S707 and S711.

As the process is typically performed on a continuous process line, before or after the splicing, tensioning of the respective materials may be performed in steps S712, S713, and S714. Typically, such tensioning is performed via a "dancer", which is configured to apply a predetermined amount of tension to the respective material. However, such tensioning is optional.

Steps S715 and S716 depict optional cleaning processes. It should be noted that the cleaning processes are depicted as taking place after the tensioning processes. However, the optional cleaning processes S715 and S716 may take place before the tensioning described in S712, S713, and S714. It is preferable that the cleaning take place after the tensioning inasmuch as it is beneficial to provide cleaning as near in time to the process that joins the respective materials together in order to avoid dust or other particles from adhering to the materials after the cleaning, but before the joining process.

Step S718 describes joining the auxiliary material to the facing material. As discussed above, this step is optional inasmuch as the auxiliary material is not included with all of the products produced. Rather, in some cases, for example when only a rubber facing material is provided, no auxiliary material will be added. In other words, the step S718 is optional, depending upon the facing material used. One embodiment of the process adds an enhanced material to a substrate material to form the facing material <NUM>. Thus, the auxiliary material may be an enhanced material such as a flocked material, a tufted material, recycled fibers, a woven fabric, a non-woven fabric, wear-layers, cotton fibers, and/or synthetic fibers, and the facing material <NUM> may be the substrate material to which the enhanced material is added.

Steps S717 and S719 describe heating the backing and facing materials, respectively. The heat process can occur to only the backing layer, and therefore, only step S717 will be included, and step S719 will be omitted. Alternatively, step S717 may be omitted and only step S719 may be provided. In another embodiment, heating can be performed after or during the joining step S720, and this heating may be used in place of or in conjunction with the heating performed in either or both of steps S717 and S719.

As the bonding material is typically a heat-activated bonding material that is solid or substantially solid at room temperature, the heat applied in steps S717 or S719 serves to activate the bonding material and allow bonding of the backing material to the facing material via the bonding material. Therefore, it is preferable to apply the heat to the backing material and/or facing material before attempting to bond the backing material to the facing material. In this way, heat stored in either the backing material or the facing material will activate the bonding material, and active heating via lamp or other heater may not have to be applied directly to the bonding material itself. As the bonding material is typically a relatively thin web, mesh, or film, it is beneficial to avoid applying heat directly to the web, mesh, or film before the bonding material is in contact with at least one of the backing or facing materials, which can provide support for the relatively weak web, mesh, or film and prevent or reduce tearing. Additionally, it is preferable to directly heat the surface of the backing or facing material (or both) that will be in contact with the bonding material inasmuch as the backing material and facing material are typically relatively unconductive (insulative) with regard to heat transfer. Therefore, applying heat to a side of the backing material or facing material opposite to the side that will be bonded via the bonding material can be wasteful because the heat energy applied to this side will have to travel all of the way through the backing or facing material in order to activate the bonding material. In other words, it is typically more efficient to heat only the area of the backing material and/or facing material that will actually transfer heat to the bonding material than it is to heat the backing material and/or facing material through its entire thickness.

As discussed above, heat may be applied to either the backing material or the facing material or both. Additionally, both of steps S717 and S719 may be omitted and heat may be applied after joining the backing material, bonding material, and facing material. Furthermore, either the step S717, which heats the backing material, or the step S719, which heats the facing material, or both, may be used in conjunction with step S721, which heats the joined material including the backing layer, bonding layer, and facing layer. After step S721, or during step S721, pressure is applied to the joined material to form a laminated layer. Additional heat may be applied after this step in step S723. However, this additional heating, like the heating described in step S721, is optional. After pressure is applied in step S722, the laminated material (backing material/bonding material/facing material combination) is cooled in step S724. The cooling may take place via exposure to ambient temperatures or may be actively performed via one or more fans or a refrigeration unit. The laminated material is then typically trimmed in step S726, although an optional inspection S725 may be performed before or after the cooling. Before or after trimming, the laminated material may be die cut in step S729, for example, into squares, rectangles, other polygons, curved shapes, or interlockable puzzle-cut pieces (see <FIG>).

In order to further allow cooling and to provide a temporary storage area for the laminated material before the material is rolled into rolls or die cut, accumulation is provided in step S727, wherein the material travels back and forth in different directions across a series of rollers. The accumulation allows a predetermined amount of laminated material to be held in the manufacturing line before rolling and partially recreates the effect of having a process line of substantially greater length than the one actually used. For example, approximately <NUM> to <NUM> feet of material may be stored in the accumulator by traveling back and forth in substantially upward and downward directions even though the accumulator is typically about <NUM> feet in length.

After the optional accumulation step <NUM>, the laminated material is wound into rolls and cut at a predetermined length in step S728 or die cut in step S729. Typically, a roll of material will then be removed from the line on a roll shuttle (see <FIG>).

<FIG> and <FIG> depict a similar process to that shown in <FIG> and <FIG>, with the exception that the bonding material is joined with the backing material in step S720a prior to heating the backing material and prior to joining the backing material to the facing material in step S720b. The same reference numbers are used in <FIG> and <FIG> as are used in <FIG> and <FIG>, aside from S720, S720a, and S720b. One benefit of joining the bonding material to the backing material before the backing and facing materials are joined is that the backing material can act as a support for the bonding material. Thus, although the bonding material is typically relatively low in tensile strength in its heated state, and therefore, usually not directly heated on its own, the bonding material can be directly heated while supported by the backing material. For example, while the bonding material is resting or moving along with the backing material, a lamp may apply radiation directly to the bonding material before the bonding material touches the facing material.

<FIG> describes a general layout of a manufacturing system <NUM> for making surface coverings as depicted in <FIG>, and <FIG>. In general, the reference numbers <NUM>-<NUM>, <NUM> and <NUM> depicted in <FIG> on the schematic representations of the various operation stations in the system <NUM> correspond to <FIG>, <FIG> and <FIG>. However, it should be noted that the general linear arrangement of the system <NUM> is not required, and nonlinear arrangements may be used. For example, the various stations <NUM>-<NUM> may be arranged in the form of an arc or segmented polygon, for example.

<FIG> represents a first portion of a system <NUM> schematically represented in <FIG>. <FIG> depicts stations <NUM>-<NUM>, and <FIG> depicts stations <NUM>-<NUM>.

With respect to <FIG>, a roll shuttle <NUM> holds a roll of backing material <NUM>. The backing material depicted in roll <NUM> typically corresponds to the backing material <NUM> depicted in <FIG>, and <FIG>, for example. A user will typically push the roll shuttle <NUM> with the roll <NUM> into position for loading onto the backing unwind station <NUM>. The backing unwind station <NUM> is typically either pneumatically or hydraulically operated so as to tilt, receive, and then lift the roll <NUM>. If the system is empty, for example after a large scale maintenance operation, then a user will thread a leader (not shown) through the system in order to pull backing material from the roll <NUM> into the system as if the system were being used for the first time. More common, however, is replacement of an empty roll <NUM> with a full roll <NUM> after the system has been in use for a period of time. In this case, material from the roll <NUM> will be spliced via a splicing station <NUM> as shown in <FIG>. In any case, the backing unwind station <NUM> is typically operated via a hydraulic, pneumatic, or electric motor <NUM> as shown in <FIG>.

<FIG> depicts a splicing station <NUM>, which, as discussed above, is used to combine material from a previous roll <NUM> with material from a new roll <NUM>. In general, material flows from the left to the right in <FIG>. Accordingly, after the splice station <NUM>, it is sometimes advantageous to adjust a tension of the material <NUM>. Accordingly, <FIG> depicts a dancer, which is a term in the art used to describe a system of rollers and framework configured to apply a predetermined amount of tension to a material conveyed via rollers. Although the dancer <NUM> depicted in <FIG> is positioned immediately after, in the direction of material movement, the splice station <NUM>, other positions may be used for the dancer <NUM>. Additionally, more than one dancer may be used in a given system <NUM> for any of the materials handled by the system.

<FIG> next depicts an optional cleaning system <NUM> through which the material <NUM> flows after passing through the dancer <NUM>. <FIG> depicts a side view of the roll shuttle <NUM>, and <FIG> depicts a top view of the roll shuttle <NUM>. <FIG> depicts an end view of the roll shuttle <NUM>, and as is evident in <FIG> and <FIG>, the roll shuttle <NUM> may include a motor <NUM> to assist in movement of the rolls <NUM> inasmuch as the rolls <NUM> often weigh approximately <NUM> pounds. As is further evident from <FIG>, the roll shuttle <NUM> typically includes a partial section of a circle in order to securely accommodate the roll <NUM>.

<FIG> depicts a detailed view of the backing unwind station <NUM>. The unwind station <NUM> pivots in response to force created by the cylinder in order to move the rotating axis point <NUM> upward and downward in order to lift and lower the roll <NUM>.

<FIG> is a detailed view of the splice station <NUM> depicted in <FIG>. As shown in <FIG>, various rollers <NUM> either passively or actively convey the backing material <NUM>. Within the splice station <NUM>, a user X adjusts a cutting surface insert <NUM> in order to splice ends of separate rolls of material <NUM> together.

<FIG> describes a dancer in detail. As discussed above, the dancer applies a predetermined amount of tension to the material conveyed within the dancer. For example, the dancer <NUM> includes a cylinder <NUM>, which may be hydraulic or pneumatic. The cylinder <NUM> is controlled via a controller to apply a predetermined amount of tension to the material <NUM> by causing the pivot arm <NUM> to pivot about the pivot point <NUM>. Typically, the cylinder <NUM> is controlled by the controller based on input from a sensor that senses a force placed upon one of the rollers <NUM>.

<FIG> depicts a facing unwind station <NUM> that unwinds a roll <NUM> of facing material such as material <NUM> discussed in reference to <FIG>. A roll shuttle <NUM> is also depicted in <FIG> and may operate in a similar manner to the roll shuttle <NUM> discussed in reference to <FIG>. Similarly, operation of the facing unwind station <NUM> is typically similar to operation of the backing unwind station <NUM>. For example, the facing unwind station <NUM> typically includes a motor <NUM> that operates to unwind the roll <NUM>. However, it should be noted that, in order to allow substantially linear operation of the system <NUM>, it is helpful to elevate the facing unwind station <NUM> relative to the level of the backing unwind station <NUM>. Alternatively, the positions of the backing unwind station <NUM> and facing unwind station <NUM> could be reversed, and the facing unwind station could be positioned at a level below the backing unwind station <NUM>. In order to achieve this difference in elevation, a system <NUM> includes a platform <NUM>, which is depicted in detail in <FIG>. Accordingly, with the platform <NUM>, it is possible to elevate one roll of material and its traveling path relative to another roll of material and its traveling path.

<FIG> depicts a splice station <NUM> for splicing the facing material <NUM> in a similar manner to the way the backing material <NUM> is spliced in the station <NUM> shown in <FIG>. In other words, the system <NUM> typically uses one roll <NUM> of material after another, and the splicing station <NUM> permits continuity of operation from one roll to the next. <FIG> also depicts an optional dancer <NUM>, which may be disposed in a position other than the one depicted in <FIG>. The dancer <NUM> is shown in more detail in <FIG>. The dancer <NUM> functions in a similar manner to the dancer <NUM> discussed in relation to <FIG>.

Furthermore, an optional cleaner <NUM> is disposed downstream of the dancer <NUM> as shown in <FIG>. The cleaner <NUM> operates in a similar manner to <NUM>. It should be noted that water recycling systems are often used with one or both of the cleaners <NUM> and <NUM>.

<FIG> depicts a roll of bonding material <NUM> disposed in a bonding material unwind station <NUM>. <FIG> also shows the facing material <NUM>, the bonding material <NUM>, and the backing material <NUM> in relation to each other.

<FIG> depicts a detailed side view of the bonding material unwind station <NUM>. As shown in <FIG> and <FIG>, which is an isometric view of the bonding material unwind station <NUM>, the material <NUM> is typically formed of sheets from two separate rolls <NUM>. Additionally, waste rolls <NUM> receive a portion of the material from <NUM>, which is used to cover the material <NUM> before use.

<FIG> describes a bonding material dancer <NUM>. <FIG> depicts a detailed view of an auxiliary material unwind station <NUM>, and <FIG> depicts the auxiliary unwind station <NUM> in isometric view. The auxiliary unwind station is used to apply an additional material to the facing material <NUM> as shown in <FIG>. For example, in some cases, the auxiliary unwind station <NUM> applies an enhanced material to a substrate material used for the facing material <NUM>. However, the auxiliary unwind station <NUM> is optional, and certain products do not require the addition of any auxiliary material <NUM>. <FIG> and <FIG> each describe a roll <NUM> of auxiliary material <NUM>, which may or may not be used in conjunction with facing material <NUM>. <FIG>, <FIG>, and <FIG> depict various views of heaters 1440A, 1440B used to apply heat to the casing material <NUM> and/or the backing material <NUM>. The infrared heater 1440A applies heat directly to a surface of the material <NUM> that eventually comes into contact with the bonding material <NUM>. Similarly, the infrared heater 1440B applies heat directly to a surface of the facing material <NUM> that comes into contact with the bonding material <NUM>. Thus, as discussed above, the surfaces that directly contact the bonding layer are directly heated via the heaters 1440A, 1440B. This direct application of heat where it is needed saves energy inasmuch as it is not necessary to heat the entire thickness of the materials <NUM> and <NUM> in order to activate the heat activated bonding material <NUM>. Rather, heat is applied where it is needed most, at the surface where the materials are to be joined.

<FIG> is a view of an embodiment of the heaters depicted in <FIG>, but with a powder scattering unit <NUM> installed for dispensing a powdered bonding material. The powdered bonding material is typically heat activatable, similar to the film discussed previously. The powder scattering unit <NUM> is most often configured to shake or cast the powdered bonding material onto the backing material <NUM> from a position above the backing material <NUM>, but other arrangements are possible. For example, if the positions of the backing material <NUM> and facing material <NUM> are reversed, then the powder scattering unit <NUM> would apply powdered bonding material to the facing material <NUM>. In one example, the powder scattering unit <NUM> is driven by a motor that stirs or shakes the powdered bonding material. The motor is typically electric or hydraulic.

In some applications, heat may be applied via another type of heater, for example, a heated blower or a heated roller. Rollers similar to those shown in various other parts of the unwind station <NUM> may be used, but with sufficient provisions made to apply heat to the roller. For example, an electric heater may be disposed inside the roller. However, the application of infrared heat to the various materials <NUM>, <NUM>, and/or <NUM> is preferred inasmuch as infrared heat can disrupt the surface tension of the material to which it is applied and therefore result in superior bonding between materials than is typically available with heat applied via convection or conduction methods alone. It should be noted, however, it is possible to add a device, such as a static electricity generator, that can disturb the surface tension of the materials <NUM> and <NUM>. The addition of this static electricity generator is often not made when infrared radiation is used to heat the materials <NUM> and <NUM>.

The heaters 1440A and 1440B typically heat the surface of the material to which they are applied to a temperature of <NUM>° to about <NUM>, more preferably from <NUM>° to <NUM>, even more preferably about <NUM> to about <NUM> (surface temp), and more preferably about <NUM> to about <NUM>. Other temperatures may be used.

One or both of the infrared heaters 1440A and 1440B may be configured to provide a gradient to the infrared radiation applied to the surface of the facing material <NUM> or backing material <NUM>. In other words, in order to prevent the edges of the heated material from overheating, it is preferable to provide greater radiation intensity at an area in the middle (away from the edges) of the facing material <NUM> or backing material <NUM> than is applied to the edges themselves. This is so because the edges of the material do not have as great of a heat sink in which to dump heat as the center of the material has. Accordingly, it is beneficial to provide a gradient to the amount of radiation applied to the heated surface. The gradient may be controlled via an electronic controller, for example, a temperature controller or a temperature program loaded onto a personal computer. Alternatively, the temperature gradient may be provided via hardwiring or may be provided via individual heat elements disposed within the heaters 1440A, 1440B with elements of greater wattage disposed toward the center of the heaters 1440A, 1440B and elements of relatively less wattage disposed toward the edges of the heaters 1440A, 1440B.

Although the temperature gradient noted above is typically preferred, especially when the materials to be heated are relatively sensitive to heat, some configurations of the system <NUM> use heaters 1440A, 1440B without providing any temperature gradient. Additionally, as discussed previously, alternative forms of heating the facing material <NUM> and/or backing material <NUM> such as heated rollers or heated air blowers may be used in place of the infrared heaters 1440A, 1440B or in addition to the heaters 1440A, 1440B. Additionally, as discussed previously, the heaters 1440A, 1440B disposed upstream of the laminator <NUM> may be replaced or augmented with heaters disposed within the laminator <NUM> itself.

<FIG> depicts a laminator <NUM> that presses together the facing material <NUM> (and auxiliary material, if any), heat activated bonding material <NUM>, and backing material <NUM> to form a laminated material <NUM>. The laminator <NUM> typically includes one or more rollers, and, as discussed previously, may include additional heaters configured to heat at least one of the facing material <NUM> and backing material <NUM>. As shown in <FIG>, material is moving from left to right, and laminated material <NUM> exits the machine at its right-hand end.

Upon exiting the laminator <NUM>, the laminated material <NUM> passes into the cooling conveyor <NUM> shown in <FIG>. The cooling conveyor <NUM> typically cools the laminated material <NUM> by applying ambient or chilled air to at least one side of the laminated material <NUM>, preferably both sides of the laminated material <NUM>. <FIG> is a detailed side view of the laminator <NUM> depicting fans <NUM> depicted above and below a path where the material <NUM> travels. It is preferable that the cooling conveyor <NUM> is from <NUM> to <NUM> feet, more preferably <NUM> to <NUM> feet, in length and that the cooling conveyor <NUM> does not include sharp bends in the path of the laminated material <NUM> inasmuch as, having recently been heated during its bonding process, the laminated material <NUM> does not typically have its full tensile strength as it leaves the laminator <NUM>. Accordingly, the cooling conveyor <NUM> typically includes a substantially straight path for the material <NUM> with fans <NUM> disposed above and/below the material <NUM> in order to allow the material <NUM> to cool before any substantial bending stress is applied to the material <NUM>. As shown in <FIG> and <FIG>, which are upper and lower plan views of the cooling conveyor <NUM>, fans <NUM> may be disposed in a staggered pattern relative to the direction of movement (left to right) of the laminated material <NUM>.

As shown in <FIG>, the fans <NUM> are configured to blow cooling air over substantially an entire width of the laminated material <NUM>. As further shown in <FIG>, there is typically a gap between the outputs of the fans <NUM> and a surface of a belt <NUM> on which the laminated material <NUM> is conveyed. This gap allows for variations in the thickness of the laminated material <NUM>. For example, the laminated material <NUM> may be anywhere from about <NUM> to about <NUM> thick, more preferably about <NUM> to about <NUM> thick, and even more preferably about <NUM> to about <NUM> thick. It should be noted that, up to a certain point, the thinner the laminated material <NUM> is, the easier it is to heat, and therefore, the easier it is to bond. <FIG> depicts the laminated material <NUM> passing over an inspection station <NUM>. In the inspection station <NUM>, a user typically visually examines the material after it has been cooled in order to discover any defects that may be present in the material. Also depicted in <FIG> is a trim station in which edges of the laminated material <NUM> may be trimmed. For example, the trim station <NUM> may comprise a water jet configured to cut a straight edge, or even a series of interlocking protrusions and cavities into the material. The interlocking cavities and protrusions form a so-called "puzzle-cut" pattern in which various pieces of laminated material <NUM> may be assembled to cover a floor the same way pieces of a child's puzzle interlock to form a picture. However, the typical procedure cuts a linear edge on the laminated material <NUM>, and any puzzle cut patterning is performed later. In one example, the trim station <NUM> cuts the laminated material <NUM> at an angle such that the facing material has a larger surface area than the backing material. In other words, the edge of the laminated material <NUM> is chamfered. One benefit of the above-noted chamfering is that, when pieces of the laminated material <NUM> are fit together, the upper surface of the laminated material <NUM>, which exposes the facing material <NUM>, abuts with an edge of an adjoining piece of laminated material <NUM> without interference from irregularities along the edge of the interior of the laminated material <NUM>. In other words, any lumps or protrusions on the sides of the laminated material <NUM> do not interfere with closely abutting the top surface of the laminated material <NUM> with an adjoining piece of the laminated material <NUM>.

After cutting with a water jet, air blowers typically blow air onto the cut material to dry it. In particular, the edges may be subjected to a directed air stream as this is the area most impacted by the water jet.

<FIG> is a detailed view of the inspection station <NUM>. The rollers <NUM> in the inspection station <NUM> are typically of sufficient diameter to prevent excessive bending of the freshly laminated material <NUM> because, as discussed previously, the laminated material <NUM> may not be at its full tensile strength. Accordingly, it is preferable to maximize the bending radius of any changes in direction in the path of the laminated material <NUM>. For example, it is preferable that the diameter of the rollers <NUM> is at least eight inches. More preferably, the diameter of the rollers is ten to twelve inches.

The inspection station typically includes a guider <NUM> that pivots about an axis P. The guider checks the material for deviation from its intended direction of travel (generally perpendicular to the axes of the rollers) and aligns the material to ensure that it does not move off of the machine. The guider <NUM> typically incorporates an electric or hydraulic motor in combination with a sensor that determines the location of the laminated material. Additional guiders <NUM> are typically disposed upstream to guide the materials used to form the laminated material, i.e., the facing material <NUM>, backing material <NUM>, and/or bonding material <NUM>.

<FIG> is an end view of the inspection station <NUM>. Typically, the rollers <NUM> have a length of approximately <NUM> inches. However, other lengths are possible, and the length can be configured as needed.

<FIG> is a side view of the trim station <NUM> shown from an opposite perspective of that depicted in <FIG>. In other words, <FIG> shows the trim station <NUM> as the laminated material <NUM> moves from right to left. As discussed previously, in some cases, it is preferable to apply a chamfer to the edge of the laminated material <NUM> when trimming. In the example of the trim station <NUM> shown in <FIG>, a nozzle of <NUM> inch in diameter (orifice) is provided. In another example, a nozzle with an orifice of <NUM> inches in diameter is provided. As shown in <FIG>, a nozzle subassembly <NUM> directs a fluid jet into a tank <NUM>, which drains into a filter assembly <NUM>. Thus, fluid used in the trimming process and ejected through the nozzle <NUM> can be recovered, filtered, and reused in order to reduce water consumption.

<FIG> depicts an accumulator <NUM> disposed downstream of the trim station <NUM>. It should be noted, however, the trim station may follow the accumulator, if desired. The accumulator typically reverses direction of the laminated material from a substantially upward direction to a substantially downward direction repeatedly in order to provide a convenient way of storing material while the material is still in an unrolled state. In other words, by repeatedly reversing the direction of the laminated material <NUM>, the accumulator <NUM> can store, for example, <NUM> to <NUM> feet of material before the laminated material <NUM> is ultimately cut and rolled into rolls <NUM> (see <FIG>). In the embodiment shown in <FIG>, about <NUM> feet of the laminated material <NUM> is shown stored in the path provided by the accumulator <NUM>.

<FIG> depicts a rewind station <NUM> in which the laminated material <NUM> is rolled into a roll <NUM>. After being rolled into the roll <NUM>, the material is typically moved away on a roll shuttle <NUM>, which may be similar in construction to the roll shuttle used to deliver the backing material <NUM> or the facing material <NUM>. <FIG> depicts a detailed view of the rewind station <NUM>, which typically includes a motor <NUM>. Similar to the backing unwind station <NUM>, the rewind station <NUM> typically includes a cylinder <NUM> that applies a moment force to pivot the rewind station <NUM> to unload the roll <NUM> (see <FIG>). The roll <NUM> is partially depicted in <FIG> before unloading. <FIG> depicts the rewind station <NUM> after unloading the roll <NUM>.

<FIG> is a schematic illustration of a computer system for operating the manufacturing system <NUM>. A computer <NUM> implements the method, wherein the computer housing <NUM> houses a motherboard <NUM> which contains a CPU <NUM>, memory <NUM> (e.g., DRAM, ROM, EPROM, EEPROM, SRAM, SDRAM, and Flash RAM), and other optional special purpose logic devices (e.g., ASICs) or configurable logic devices (e.g., GAL and reprogrammable FPGA). The computer <NUM> also includes plural input devices, (e.g., a keyboard <NUM> and mouse <NUM>), and a display card <NUM> for controlling monitor <NUM>. In addition, the computer system <NUM> further includes a floppy disk drive <NUM>; other removable media devices (e.g., compact disc <NUM>, tape, and removable magneto-optical media (not shown)); and a hard disk <NUM>, or other fixed, high density media drives, connected using an appropriate device bus (e.g., a SCSI bus, an Enhanced IDE bus, or a Ultra DMA bus). Also connected to the same device bus or another device bus, the computer <NUM> may additionally include a compact disc reader <NUM>, a compact disc reader/writer unit (not shown) or a compact disc jukebox (not shown). Although compact disc <NUM> is shown in a CD caddy, the compact disc <NUM> can be inserted directly into CD-ROM drives which do not require caddies. In addition, a printer (not shown) also provides printed listings of tracked temperatures and tomographic information.

As stated above, the system includes at least one computer readable medium. Examples of computer readable media are compact discs <NUM>, hard disks <NUM>, floppy disks, tape, magneto-optical disks, PROMs (EPROM, EEPROM, Flash EPROM), DRAM, SRAM, SDRAM, etc. Stored on any one or on a combination of computer readable media is the software for controlling both the hardware of the computer <NUM> and for enabling the computer <NUM> to interact with a human user. Such software may include, but is not limited to, device drivers, operating systems and user applications, such as development tools. Such computer readable media further includes the computer program product for tracking temperature and tomographic information. The computer code devices can be any interpreted or executable code mechanism, including but not limited to scripts, interpreters, dynamic link libraries, Java classes, and complete executable programs. The computer <NUM> is typically configured to execute code stored in one of the above-noted computer readable media, which, when executed on the computer <NUM>, causes the computer <NUM> to operate the manufacturing system <NUM> to perform any of the processes described in this document and to produce any of the products described in this document.

The process and system described above may be arranged to handle various thicknesses of material <NUM>. For example, from one millimeter to <NUM> millimeters. Additionally, various widths of materials may be accommodated in the processes and system described above. For example, widths from a few inches to a dozen feet may be implemented.

<FIG> is a view of a puzzle-cut flooring material according to one embodiment of the invention with a series of interlocking cavities <NUM> and protrusions <NUM>. This arrangement can be applied to any configuration of the product <NUM>. In many cases, the cavities <NUM> and protrusions <NUM> will interlock such that a first piece the product <NUM> will have to be lifted relative to an interlocked second piece of the product <NUM> in order to release the protrusions <NUM> of the first piece of the product <NUM> from the cavities <NUM> of the second piece of the product <NUM>. Additionally, the edge of the product <NUM> is often chamfered with a chamfer CH (see <FIG>). In one example, the chamfer CH is approximately <NUM> degrees, which results in a slightly larger surface area for the top portion of the product <NUM> relative to the bottom portion. As discussed previously, this chamfer allows adjacent pieces of the product <NUM> to rest next to each other (or interlock) without interference from irregularities in the sidewalls of the product <NUM>. One benefit of this arrangement is that seams between the top surfaces of the interlocked pieces of the product <NUM> are less visible from above. A chamfer such as the one depicted in <FIG> can be applied to the product <NUM> regardless of whether the product includes cavities <NUM> or protrusions <NUM>. In other words, the chamfer CH can be applied to straight edges of the product <NUM> as well as to curved edges. Other shapes and sizes of cut pieces of the flooring may be made, aside from the puzzle-cut flooring shown in <FIG>. For example, large or small circles, polygons, curved pieces, and strips may be produced.

Although the product <NUM> depicted in <FIG> includes cavities <NUM> and protrusions <NUM> on all four sides as viewed from above, the shape of the product <NUM> and the number of sides on which cavities <NUM> and protrusions <NUM> are present can vary. For example, in many instances, it is preferable that one or more of the sides of the product <NUM> are straight so that these sides present an edge that fits along a wall, into a corner, or defines a particular living/working space. In some cases, the straight edges are un-chamfered while the interlocking areas are chamfered. In other cases, all the edges are chamfered, even the straight edges.

<FIG> depicts a first portion of a die cutting system that may be implemented in combination with the lamination system described above. In one embodiment, the die cutting system is entirely detached from the lamination system, and rolls <NUM> are positioned in an unload or unwind station directly in front of a stencil table <NUM>. In such an arrangement, one benefit is that the die cutting station may be used with materials unrelated to those currently being produced in the lamination system. Another benefit is that the rolls <NUM> may be temporarily stored before being die cut. In this way, the final form of the material in the rolls may be determined well after the lamination is completed.

In another arrangement, product <NUM> bypasses the rewind station <NUM> and travels along a bypass conveyor <NUM> and toward a mini-accumulator <NUM>. The mini-accumulator <NUM> may be the same or similar to the accumulator <NUM> discussed previously. Typically, however, the mini-accumulator <NUM> stores less material than the accumulator <NUM>. By storing material in the mini-accumulator <NUM>, the infeed table <NUM> (see <FIG>) can continuously supply the press <NUM> (shown in <FIG>). In other words, as the laminator system typically feeds material continuously, and sometimes at a substantially constant rate, the mini-accumulator <NUM> allows a build-up of material to supply the press <NUM>, which typically functions as an indexing machine inasmuch as material starts and stops in order to feed the press <NUM>.

As shown in <FIG>, the press <NUM>, once having pressed a pattern into the product <NUM>, sends the pressed, i.e., cut, material to the outfeed table <NUM> which then may send the material to a take-away conveyor <NUM> that feeds a shuttle conveyor <NUM> that stacks the cut pieces in a stack <NUM>. Alternatively, the cut pieces produced by the press <NUM> may be stacked by hand rather than handled by a take-away conveyor <NUM> and shuttle conveyor <NUM>.

The press <NUM> typically uses a belt such as a urethane belt in order to accommodate the pressing action used to cut the product <NUM>. The flexible belt supports the product <NUM> during the pressing portion of the die cutting process. To perform die cutting, the press <NUM> exerts a force on the product <NUM> and shears the product <NUM> into any of various shapes such as squares, rectangles, other polygons, circles, or the above-noted puzzle-cut pieces. The die cutting system may be controlled by the same controller used to the control the lamination system or may have its own controller or computer system. In one embodiment, the die cutting system is operated via manual control.

Claim 1:
A laminated surface covering, comprising:
a layer of backing material, an adhesive, and a layer of facing material,
wherein the backing material comprises a continuous layer of a backing material and the facing material comprises a continuous layer of a facing material,
wherein the adhesive bonds the continuous layer of the facing material directly to the continuous layer of the backing material and comprises a layer of heat-activated bonding material that is in a solid or semi-solid form at room temperature <NUM>,
wherein the facing material is an EPDM rubber or a wood-grain PVC, and
wherein the backing material includes a rubber material.