Patent Application - ADHESIVELESS DECORATIVE FLOOR TILE > Description
This application is a continuation-in-part application of copending U.S. Patent application Ser. No. 12/923,369, filed Sep. 16, 2010, and entitled Hollow Base Decorative Surface Covering; copending U.S. patent application Ser. No. 13/165,246, filed Jun. 21, 2011, entitled Adhesiveless Decorative Floor Tile, and also claims priority from Provisional Patent Application Ser. No. 61/463,962, filed on Feb. 25, 2011, entitled Surface Covering Having A Back Surface Comprising Hollow regions.
The present invention relates to decorative surface coverings, including flooring materials.
Sub-floor surfaces are often covered with resilient flooring products using adhesives. Such adhesives may be applied directly to the sub-floor, or to the back of the resilient tile products by the manufacturer. Flooring products often stay in place during use, and can be subjected to walking forces, dragging forces, rolling load forces, indentation forces, and sub-floor movement due to dimensional instability. Flooring products must stay flat, not curl. Seams, especially between tiles, must not move or open. There have been many attempts to develop flooring products that do not require adhesives. Some involve so-called “loose lay” constructions as taught in U.S. Pat. Nos. 4,698,258 and RE34,357. Many interlocking tile designs have been the subject of prior art patents. Recently, U.S. Pat. No. 7,155,871 discloses two-sided ship-lap vinyl plank with adhesive located on the ship-lap surface. However, none of these tile technologies have had significant commercial success. There remains a need for resilient decorative floor tiles that do not require adhesives.
Suction cups have been utilized in bath mat constructions as defined in U.S. Pat. Nos. 6,014,779 and 2,081,992, and US Patent Application No. 2005/0100711. While this approach provides acceptable slip-resistance for light shower and bath mat applications, traditional suctions cups do not provide sufficient anti-skidding forces to prevent slippage do to movement in high traffic and high load areas. Traditional suction cups often yield an uneven mat surface which is more difficult for individuals and loads to traverse.
One embodiment of the present invention provides an adhesiveless decorative floor tile that includes a decorative layer and a backing layer. An array of discreet continuous resilient projections are located on an outer surface of the backing layer. The array of resilient projections are arranged with respect to one another so as to form recessed regions that are defined by the resilient projections so that when pressure is applied to the decorative layer, a partial vacuum is formed within each recessed region allowing the decorative floor tile to remain in place on a surface in the absence of adhesive. When the decorative floor tile is installed over an underlying surface, e.g., a sub-floor the vacuum increases the amount of frictional drag between the decorative tile and the underlying surface, thus allowing the decorative tile to remain in place without the need for an adhesive.
In another embodiment, a decorative floor tile includes at least one decorative layer and a backing layer comprising an array of resilient continuous sinusoidal walls, wherein each wall comprises an exposed top surface, an outside wall surface, and together define a void between adjacent walls. When the decorative floor tile is installed over an underlying surface, and pressure is applied to the decorative floor tile, at least a partial vacuum is created within portions of the void between projections which adheres the floor tile to the underlying surface. The partial vacuum increases the amount of frictional drag between the tile and the underlying surface, and thus allows the tile to remain in place without the need for an adhesive.
This description of preferred embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. The drawing figures are not necessarily to scale and certain features of the invention may be shown exaggerated in scale or in somewhat schematic form in the interest of clarity and conciseness. In the description, relative terms such as “horizontal,” “vertical,” “up,” “down,” “top,” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation. Terms including “inwardly” versus “outwardly,” “longitudinal” versus “lateral,” and the like are to be interpreted relative to one another or relative to an axis of elongation, or an axis or center of rotation, as appropriate. Terms concerning attachments, coupling, and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. The term “operatively connected” is such an attachment, coupling or connection that allows the pertinent structures to operate as intended by virtue of that relationship.
Decorative layer 2 may be traditional laminate flooring products having a decorative layer. Some examples include the interlocking type of laminate flooring products such as those described in U.S. Pat. Nos. 6,851,241, and 6, 006,486 which have found commercial success as “free floating” flooring. These flooring products employ a foam underlayment between the laminate product and the underlying sub-floor. In some cases, the foam underlayment can be attached to the underside of the laminate product by the manufacturer. We have discovered that utilizing the backing layer 3 of the current invention in place of the traditional foam has advantages over the prior art. Backing layer 3 not only helps to keep the laminate in place, but also provides some improvement in impact sound and transmitted sound properties. The laminate product structure has increased thickness and stiffness, and show-through of the geometric array of backing layer 3 is less of an issue. In the case of laminate products as decorative layer 2 height may often be increased.
Array 4 of annular projections 5 is often organized in rows 6 that are parallel to the decorative layer's longitudinal edge 7, with alternating rows 8 offset on center across the width of array 4. Referring to
In some embodiments of the invention, the distance 10 between annular projections 5 within the rows, and between the rows 10′, is between about 1.0 mm-1.2 mm with the alternating rows off-set 11 between about 2.4 mm-2.6 mm on center across the width of array 4. Annular projections 5 are preferably defined by an inside surface 12 and an outside surface 13, that together define a ring wall 20 of each projection 5. The inside diameter of passageway 9 defined by inside surface 12 is often in the range from about 1.9 mm-2.1 mm. The outside diameter of each annular projection 5 is often in the range from about 3.7 mm-4.0 mm resulting in a ring wall thickness 14 of between 0.75 mm-1.2 mm. An exposed, top edge 15 of each ring wall 20 may define a concave surface. Each annular projection preferably has a height 16 in the range from about 0.8 mm-1.2 mm above the surface of backing layer 3 which has a thickness 17 in the range from about 0.13 mm-0.17 mm. Annular projections 5 may also comprise, triangles, squares, rectangles, ovals, pentagons, hexagons, other polygons, or mixtures thereof.
It is within the scope of this invention to change size, number, shape, and dimensions of the annular projections 5 depending upon size and shape of decorative layer 2. In principle, annular projections 5 should be located as close to the edges of the tile as practically possible to ensure seam integrity between tiles, and to ensure that the resulting product performs acceptably without adhesive, in particular, during exposure to traffic/walking and rolling loads after installation. In some embodiments, annular projections 5 are symmetrical with dimensions equal in both longitudinal and transverse directions providing maximum adhesion in both directions. In other embodiments, annular projections 5 have the shape of ovals, rectangles, or other geometric shapes with zero, or only one axis of symmetry, often a symmetry ratio between major dimension (length) and minor dimension (width) through the “center of figure” of about 6.4 cm or less has been employed with good results. In another embodiment, the symmetry ratio is about 3.8 cm or less. As shown in
The distribution of annular projections 5 and the relative size of internal passageways 9 on backing layer 3 determine the increase in adhesion to the underlying surface that will be produced by the partial vacuum formed between each internal passageway 9 and backing layer 3. The number of annular projections 5 on the exposed surface of backing layer 3 is in the range from about 2,000 to about 6,000 per square foot. Often, the size of internal passageway 9 has a maximum horizontal dimension from a vertical sidewall through the “center of figure” of annular projections 5 to the opposite vertical sidewall in the range of 0.05 cm to 0.65 cm. The maximum horizontal dimension of internal passageways 9, where the decorative layer is resilient flooring, is in the range of 0.05 cm to 0.33 cm. In some embodiments, the width 14 of annular projections 5 can also be varied, but is generally in the range of 0.04 cm to 0.25 cm. In some embodiments the height 16 of annular projections 5 is between 0.01 cm -0.02 cm, and in other embodiments height 16 may be in a range between 0.0076 cm-0.00127 cm. Height 16 of annular projections 5 is important in defining the volume of internal passageway 9, and the ability to create a vacuum when compression is applied to the decorative floor tile. Additionally, when included, concave surface 15 of annular projections 5 which is normally in physical contact with the underlying subfloor facilitates creation of a further partial vacuum during compression. However, in less preferred embodiments surface 15 may be flat, i.e., non-concave. This flat region is located near the center of the surface 15 and not adjacent either vertical wall 12, 13 of annular projections 5.
Oscillating walls 43 each form an internal wall that projects upwardly from backing layer 28 so as to define passageways 47 and often run either transversely or longitudinally relative to peripheral edge walls 49 of backing layer 28. As shown in
Array of resilient projections 41 are best formed from materials that are able to spring back quickly into shape after being bent, stretched, or squashed, i.e., resilient materials that are capable of storing and releasing energy. Elastomeric compounds are one such resilient material that has been found to yield acceptable results when incorporated with the structures of the present invention. Any elastomeric composition that is compatible with the decorative layer 2 may be selected for the backing layer. Typical elastomeric compounds, provide acceptable physical performance, and possess adequate coefficient of friction properties to maintain the decorative floor tile in place without adhesive. In one embodiment, the elastomeric composition is a flexible vinyl composition including plasticized pvc or pvc/polymeric blend. In another embodiment, rubber materials including thermoplastic and thermoset rubber compositions are employed. The rubber compositions can include, but are not limited to natural or synthetic rubbers, acrylic elastomers, polyester elastomers, polyurethane elastomers, pvc elastomers, polyolefin elastomers, and blends of these materials. The elastomers can comprise homo-polymers, co-polymers, ter-polymers, block co-polymers or blends thereof. An optimal wave shape for oscillating walls 43 can be influenced by the desired structural response, e.g., a non-periodic, non-sinusoidal wave shape may be preferred in some instances. There are other variables such as selection of materials, relative thickness of the entire decorative floor tile that are important for correct design in addition to selection of wave shape. The selection of these details will be necessarily customized for different designs and will be obvious to one skilled in the art, upon review of this disclosure.
In another embodiment, fiberglass fibers are incorporated into the vinyl tile or plank structure comprising the backing layer of the invention. Incorporation of fiberglass fibers provides increased dimensional stability and also improves flame resistance properties of the composite. In one embodiment, the fiber glass fibers are directly incorporated into the vinyl tile or plank structure before the backing layer of the invention is applied. In another embodiment, the fiberglass fibers are incorporated into the backing layer before or during lamination/molding onto the tile or plank structure. It is understood that the fiberglass fibers can comprise individual glass fibers, or non-woven or woven glass mats. Additionally, other fibers can be employed if they impart the improved dimensional stability and flame resistance.
The process of manufacturing a decorative floor tile in accordance with one embodiment of the invention involves the following steps: 1) selecting a decorative layer, for example a 6″×36″ Luxury Vinyl Tile Plank; 2) designing an appropriate array of projections to fit size and properties of the selected decorative layer; 3) manufacturing the backing layer comprising the array of projections; and laminating the backing layer to the decorative layer to produce the product of this invention. In some instances, the third step involves making a metal plate or mold that is a “negative” of the array of Step 2), applying an elastomeric composition onto the metal plate or mold, and using a predetermined pressure and heat to cause the elastomeric material to fill the negative plate, thus creating the array, At this point, the elastomeric backing layer can be removed from the metal plate or mold and subsequently laminated to the decorative layer, or the decorative layer can be placed onto the elastomeric coated metal plate or mold and laminated to the decorative layer using heat and pressure, and subsequently removed. The pattern for any particular array may be machined in the aluminum plate to the desired depth and shape of the projections. The machining tool is often equipped with the desired concave surface and width of annular projections 5. In another method a polymeric elastomeric layer is prepared and mechanically embossed using an embossing roll or plate to produce the selected array of Step 2. This process can be utilized with thermoplastic and thermoset elastomeric compositions. Generally, the thermoset elastomer layer will be embossed before final curing of the thermoset elastomeric composition.
Lamination of the decorative layer and the backing layer with an array of projections formed in accordance with the present invention can be accomplished by many known techniques. In addition to utilizing heat and pressure to accomplish the lamination, the use of an adhesive layer between the decorative layer and the base layer may be required. Many of the adhesives known to those of ordinary skill in the flooring arts exist for this purpose. The only requirement of the adhesive is that it is chemically compatible with the decorative layer and the backing layer, and provides acceptable performance during the lifetime of the installed decorative floor tile. It will be understood that the backing layer can be manufactured in sheet form with multiple decorative layers laminated thereto.
The proceeding description of the invention has shown and described certain embodiments thereof; however, it is intended by way of illustration and example only and not by way of limitation. Those skilled in the art should understand that various changes, omissions and additions may be made to the invention without departing from the spirit and scope of the invention as defined by the claims.