Removable and Recyclable/Reusable Vinyl Tile and Method of Using Same

The present disclosure is directed to a removable and recyclable/reusable vinyl tile, and more particularly, to a vinyl tile that can be removed from a subfloor without take-up of adhesive, and recycled or reused.

Vinyl tile or planks have become a standard for new buildings and remodeling. Gone are the days when vinyl tile had limited appeal and aesthetics, was generally laid down in 12 inch by 12 inch squares and had poor wear. Today's vinyl tile, some of which is colloquially referred to as luxury vinyl tile (LVT), can have an appearance and aesthetic as good as natural wood or stone, a consistent look and feel, is available in an extremely wide variety of colors and patterns, wears extremely well, and is made of generally readily available materials.

While LVT has made it possible to obtain flooring that appeals to almost any aesthetic, there are drawbacks.

For example, the forthcoming newly revised European Construction Products Regulation (CPR) and the European Green Deal may require construction products to be designed in such a way that they can be recycled or re-used at the end of their installed life. Many markets for LVT are glue-down markets. The disadvantage with this system is that if the end user wishes to replace the tiles, the removed tiles are not easy to re-use because when uplifted, they are usually damaged or distorted and contaminated with adhesive and levelling compound/screed from the subfloor. Further, contamination of the tile makes recycling difficult as well, as the contaminants are not easily removed and can adversely affect the recycling process.

There are other types of tiles, however, each of these has drawbacks as well. For example, peel and stick tiles have been on the market for many years. However, these tiles are prone to the adhesive being ‘blinded’ by picking up dust from the subfloor during installation, which reduces bond strength. While such tiles may be repositionable during installation, at the end of installed life they retain a layer of adhesive on the backing, and as such the tiles are prone to contamination and adhesion of dust, and are difficult to handle, thereby rendering them more difficult to re-use. Indeed, the dust and contamination may significantly reduce or prevent adhesion.

In another type of LVT installation, a levelling compound is first applied to a subfloor, and a polypropylene mesh is laid out on the dried levelling compound. A wet set adhesive is applied to the mesh before the floor tiles are applied. At the end of product life, the floor tiles can be uplifted free of adhesive residue on their underside. The adhesive/mesh composite is scored and peeled clean away from the levelling compound which is left in a good state for the process to be repeated with fresh mesh/adhesive/tiles. However, significant disadvantages are that the tiles are not reusable as they will distort during uplift, and the adhesive and mesh must be disposed of at the end of product life as non-recyclable waste.

In still another known system, a self-adhesive sheet is positioned between the subfloor and the floor covering. The adhesive strength is different on the upper and lower surfaces of the sheet. A significant disadvantage is that the system may not prevent thermal expansion and contraction of the floor covering during installed use. And like other systems, at the end of product life, once uplifted, the floor covering remains bonded to the adhesive sheet which must be disposed of along with the floor covering. The presence of adhesive between the sheet and the floor tile may limit the ability to recycle the floor covering.

Accordingly, there is a need for a flooring system that provides an alternative to glue-down systems. Desirably, the tiles of such a system are readily reused or recycled at end of life. More desirably still, in such a system there is little to no adhesive remaining on the underside of the tile or plank at uplift to permit reuse or recycling following uplift. Still more desirably, in such a system, the tile can be uplifted without distorting it, such that it is suited for subsequent reuse.

In an aspect, a recyclable and reusable tile includes at least three layers, a stability layer, a design layer, and a wear layer. The tile defines an upper surface and a lower surface. The stability layer includes a glass or glass-based reinforcement, and the tile has a flexural modulus in a range of about 1000 MPa to about 3000 MPa. In embodiments, the flexural modulus is in a range of about 1500 MPa to about 1700 MPa, and preferably about 1600 MPa. In embodiments, the tile is a vinyl tile. The stability layer can be, for example, a PVC-based material.

In embodiments, the tile includes a backing. The backing can be a PVC-based material or a non-PVC-based material. The PVC-based backing can have a surface roughness (Ra) less than about 5 μm, and preferably less than about 2 μm.

The backing can be a non-PVC based material. Suitable non-PVC-based materials include, but are not limited to, one or a combination of polyethylene (PE), polypropylene (PP), olefin copolymers, rubbers, and ethylene vinyl acetate (EVA).

In embodiments, the stability layer includes a glass fleece material. The stability layer can further include a filler.

In embodiments, the tile includes at least four layers, and includes a stability layer, a design layer, a wear layer, and a surface layer. The design layer can be printed on the stability layer. The stability layer can be formed having a partial cellular structure.

In another aspect, a combination of a recyclable and reusable tile, and an adhesive, includes the recyclable and reusable tile that has at least three layers, a stability layer, a design layer, and a wear layer. The tile defines an upper surface and a lower surface, and the stability layer includes a glass or glass-based reinforcement. In embodiments, such a tile has a flexural modulus in a range of about 1000 MPa to about 3000 MPa, and the stability layer is a PVC-based material and includes a glass fleece material.

The adhesive is a low tack adhesive. The adhesive can be, for example, an acrylic copolymer based material. The acrylic copolymer based material can have a low glass transition temperature. The adhesive can be a moisture resistant polymeric material. Suitable adhesives can include pressure-sensitive adhesives.

In embodiments, the flexural modulus of the tile is in a range of about 1500 MPa to about 1700 MPa and preferably about 1600 MPa.

The tile can include a backing. The backing can be a PVC-based material or a non-PVC-based material. The PVC-based material backing has surface roughness (Ra) less than about 5 μm, and preferably less than about 2 μm.

In tiles having the non-PVC based backing material, suitable non-PVC-based materials include one or a combination of polyethylene, polypropylene, olefin copolymers, rubbers, and ethylene vinyl acetate.

In still another aspect, a method of installing a recyclable and reusable vinyl tile surface on an associated subfloor includes providing a tile having at least three layers, a stability layer, a design layer, and a wear layer, the tile defining an upper surface and a lower surface, the stability layer includes glass fleece reinforcement material, and the tile having a flexural modulus in a range of about 1000 MPa to about 3000 MPa, applying a low tack adhesive to the associate subfloor, and applying the tile to the adhesive.

In some methods, the adhesive is applied in a nonconformal application. Such a nonconformal coating provides channels between areas of adhesive.

Still other methods include removing the tile from the subfloor and, upon removal of the tile from the subfloor, less than about five percent of the adhesive remains on the tile. Preferably, less than about 1 percent of the adhesive remains on the tile. The tile can be reapplied to another associated subfloor or recycled.

The foregoing general description and the following detailed description are examples only and are not restrictive of the present disclosure.

While the present disclosure is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described presently preferred embodiments with the understanding that the present disclosure is to be considered an exemplification and is not intended to limit the disclosure to the specific embodiments illustrated.

In an aspect, the present disclosure is directed to a luxury vinyl tile or plank(collectively referred to as “tile” or “LVT”) system, and a system for installing the tile that permits the tilesto be readily removed from a subfloor S without warping or distorting the tile, and can be recycled or reused in that the adhesiveused to adhere the tileseparates from the tilewhen the tileis removed (pulled up or uplifted) from the subfloor S.

The LVT system includes a tile or plankand an adhesive. Referring to, there is shown an embodiment of a tile. The illustrated tileis a multi-layered construction and includes a lower or stability layer, a design layer, a wear layer, and a surface layer. In embodiments, the tileis stiffer than a standard glue-down type tile so that it does not distort when uplifted and can be re-used, but is not as stiff as standard ‘rigid core’ floors which have no drape at all and may not lie flat if the subfloor S itself is not totally flat.

In some embodiments, the tilescan be polyvinylchloride (PVC) backed or PVC-based material backed tiles. Other embodiments are non-PVC or non-PVC-based material backed tiles. The backings or undersurfacesof non-PVC backed tiles can be foamed or unfoamed, and can be crosslinked or uncrosslinked. Suitable backing materials include but are not limited to polyethylene (PE), polypropylene (PP), olefin copolymers, rubbers, ethylene vinyl acetate (EVA), and the like. Preferably such a backing does not form a strong nor permanent bond to the tackifier used. Roughness of the backing for the non-PVC backed tiles is less significant in that the backingmaterial can be selected to reduce adhesion of the tackifier. Desired roughness for the PVC or PVC-based material backed tiles is discussed in more detail below.

A present tileis also sufficiently stiff to prevent ‘grin through’ of adhesive, which is exhibited when, in standard flexible vinyl flooring installations, features of the application adhesive may be visible when the surface of the installed floor is viewed under certain lighting conditions.

In embodiments, stiffness is provided by at least the stability layer. The stability layercan, for example, include a glass mesh/fleece layer, a fiberglass reinforced layer, or the like that helps the tileto lay flat and level, and increases dimensional stability and mechanical strength. The stability layerconfers resistance to thermal expansion/contraction during installed use. The stability layercan be a partial cellular structure to, for example, reduce the weight of the tileand to provide increased cushioning/impact resistance and acoustic properties over a solid layer structure, such as a subfloor S. It will be appreciated that systems that use reinforcements in the nature of chopped glass fibers or glass nets may not confer the dimensional stability necessary to prevent tile contraction when room or ambient temperatures drop. As such, a preferred stability layerincludes an integral reinforcement such as glass fleece. Foaming the stability layer(e.g., creating a partial cellular structure) is optional and may reduce the overall density of the tile. It is anticipated that in embodiments, a desired flexural modulus (E) of the tileis in a range of about 1000-3000 Megapascals (MPa), preferably about 1500-1700 MPa and more preferably, about 1600 MPa.

Table 1 below shows typical flexural modulus (E) ranges for flexible, semirigid, and rigid tiles. As can be seen, the present tile falls at about the semirigid range, although it can fall below the semirigid range and into the flexible range while still maintaining its dimensional stability, and demonstrates the increased stiffness of the present tile over standard LVT designed for gluedown.

Table 2, below illustrates the flexural modulus of common flooring products.

Also unlike known glue-down type tiles, the present tilecan have a smooth or relatively smooth bottom surface or backing, and particularly, PVC or PVC-based material backing. Known tiles have a textured back to increase the surface area of the adhered tile surface to the subfloor. In contrast, the smooth or relatively smooth backingof the present tile, and in particular the smooth backingof the PVC or PVC-based material backed tiles, reduces the surface area of the adhered surface of the present tile, which facilitates removal of tilewithout the adhesiveremaining on the tile back surface. It is anticipated that in embodiments, a desired surface roughness of the PVC or PVC-base material backed tilesis less than about 5 micrometer (μm) and preferably less than about 2 μm. Table 3 below illustrates the surface roughness of common flooring products.

In Table 3, above, Ra is the arithmetic mean of the absolute departures of the roughness profile from a mean line, Rz is the maximum peak to valley height of the profile within the sampling length, Sa is the difference in height of each point compared to the arithmetic mean of the surface, and Sz is the sum of the largest peak height value and the largest pit depth value within the defined area. It is to be understood that the surface roughness of the non-PVC or non-PVC-based material backed tiles is less relevant than it is for the PVC or PVC-based material backed tiles as the backing materials for the non-PVC or non-PVC-based material backed tile can be selected so as to influence clean separation of the tackifier from the tile upon uplift.

It will be also appreciated by those skilled in the art that using a conventional, non-reinforced vinyl tile designed for standard glue-down (which tiles do not usually contain a tile reinforcement) would likely lead to gaps forming between tiles during episodes of abnormally low room temperature or ‘tenting’ during periods of high room temperature. This is due to pressure sensitive adhesive systems suffering from lower shear resistance. Gapping and tenting can be reduced or alleviated by the dimensional stability of the present tile.

In the illustrated example tile, adjacent and above the stability layer is the design layer. In embodiments the design layeris a high definition photographic layer. This layerprovides the aesthetic foundation for the tile. Such a design layercan include a wide variety of colors/tones, patterns, and the like to the tile. It is also anticipated that in embodiments, the design layercan be digitally printed, and can be digitally printed directly onto the layer below, for example the design layermay be digitally printed directly onto the stability layer.

In embodiments, a wear layeris adjacent the design layer. In an embodiment, the wear layeris a polyvinylchloride (PVC) or like layer. The PVC layercan be a clear layer and can be embossed to further the aesthetics and texture of the tile.

The tilecan also include a surface layer. The surface layercan be a protective layer, such as a polyurethane (PU), or PU/acrylic layer to provide a hygienic and durable surface feature for the tile. Such a protective surface layercan also provide protection from prolonged exposure to the sun, ultraviolet exposure and the like. In embodiments, it is anticipated that a single layer encompassing the wear layerand the surface layermay be used. In such an embodiment, the single wear/surface layer (/) can be, for example, a polyvinyl chloride (PVC) layer, a polypropylene (PP) layer, a polyethylene terephthalate (PET) layer or the like.

In a current example tile, the composition of the tileis as follows:

In an embodiment, the PU surface layercoating is about 15 g/m, the wear layeris about 360 g/m(noting that the wear layer can vary in thickness according to the end application), the design layeris about 70 g/m, and the stability layeris about 6100 g/m(noting that the overall thickness of the tilecan vary according to choice).

As noted above, embodiments of the tilecan include a number of layers (although four are shown, the tilecan include more or less layers), at least one of which includes the reinforced stability layerto minimize temperature effects on the tile. That is, the stability layerwill minimize the lateral (i.e., in a plane of the subfloor S) expansion and contraction of the tileduring normal room/location temperature fluctuations.

In a current system, the adhesive systemis referred to as a tackifier adhesive or tackifier, and is part of the family of pressure sensitive adhesives (PSAs). Such a tackifier/adhesiveis typically a blend of soft, i.e., low glass transition temperature (Tg) acrylic copolymers with some harder copolymers (higher Tg). PSAs are used as they provide freestanding releasable properties and they remain permanently tacky, rather than dry/cure to a hard surface. A preferred adhesiveis a moisture resistant polymer. Such an adhesiveholds the tilesecurely in position during installed life.

Characteristics of a suitable tackifier include a viscosity of about 80 cP (centipoise) to about 9000 cP, and preferably about 3000 cP to about 9000 cP, and a solids content of about 45 percent by weight.

One example of a suitable tackifier has the following formulation:

On the one hand, when the viscosity of the tackifier is too high, it can be difficult for the installer to spread the tackifier and it can also increase the drying time (as the surface area of the applied adhesive is low). On the other hand, if the viscosity of the tackifier is too low, the tackifier may spread out thereby forming a conformal layer after application. It will be appreciated that for many such tackifiers, time for a milky white adhesive to appear transparent is the ideal point to apply the tiles onto the tackifier.

A preferred tackifier has a peel strength of less than about 1.0 N/mm and preferably less than about 0.5 N/mm to reduce the opportunity for distortion upon uplift. Such a tackifier also has a shear strength of greater than about 0.3 N/mmto limit lateral expansion/contraction of the tile during changes in room temperature. The peel and shear strength and dimensional stability for floor covering products covered by ISO 10581 and 10582 are measured in accordance with ISO 22636:2020, Adhesives for Floor Coverings—Requirements for Mechanical and Electrical Performance, which provides that for PVC floor coverings, the acceptable peel strength is greater than or equal to 1 N/mm, acceptable shear strength is greater than or equal to 0.3 N/mmand dimensional change (longitudinally and transversely) is less than or equal to 0.2 percent.

To facilitate readily removing the tilefrom the subfloor S (which may be a leveling compound), the adhesive'sreleasable qualities are such that the adhesiveremains entirely or substantially entirely on the subfloor S (e.g., leveling compound) and not on the undersideof the tilewhen the tileis uplifted. Such an adhesive/tackifierremains permanently tacky, and is of sufficiently low tack such that release of tileat end of product life occurs without causing any distortion or loss of squareness to the uplifted tile. This permits reuse of the tileif, or as, desired.