FOAM MAT

Abstract

A two layer foam mat is described. The raw materials for each layer are separately mixed and heated in different batches, and separately pressed through heated rollers to form a plurality of sheets. One or more sheets from each batch are stacked together in a press and heated above a foaming temperature to permit the stacked sheets to foam and expand. The press restricts the sheets from vertical expansion while allowing horizontal expansion. Once the sheets are foamed, a series of alternating teeth and receiving slots can be cut around the boundary of the mat to form an interlocking peripheral wall. The layers preferably have the same chemical composition after foaming, even though the layers are formed from different batches and may have different colors and/or textures.

Claims

1. A foam mat comprising a body bounded by an interlocking peripheral wall, the body comprising: a first layer made from a first batch of raw materials comprising a first polymer and a second polymer; a second layer made from a second batch of raw materials comprising the first polymer and the second polymer; wherein the first layer and second layer are made by (i) separately heating and mixing the first batch of raw materials and the second batch at a temperature that is below a foaming temperature of the first batch of raw materials and the second batch of raw materials, respectively; (ii) separately heating and pressing the first batch of raw materials and the second batch of raw materials through rollers that are maintained within uniform temperatures of a range of 5 C. to form a first plurality of sheets and a second plurality of sheets, respectively; and (iii) stacking, pressing, and heating one or more of the first plurality of sheets and one or more of the second plurality of sheets to a temperature that permits the sheets to foam and expand; and wherein, after foaming and expansion, the first layer comprises a first chemical composition and the second layer comprises a second chemical composition that is substantially similar to the first chemical composition so that the first layer and second layer respond similarly when subject to temperature changes and forces.

2. The foam mat of claim 1 wherein the first polymer comprises ethylene vinyl acetate (EVA) and the second polymer comprises polyethylene (PE).

3. The foam mat of claim 2 wherein the EVA is recycled EVA, and the PE is virgin PE.

4. The foam mat of claim 2 wherein the EVA is virgin EVA, and the PE is recycled PE.

5. The foam mat of claim 2 wherein the EVA is virgin EVA, and the PE is virgin PE.

6. The foam mat of claim 1 wherein the second batch of raw materials comprising the same amount of the first polymer and the second polymer as the first batch of raw materials.

7. The foam mat of claim 1 wherein the first layer and the second layer have the same coefficient of thermal expansion and the same elastomeric properties.

8. The foam mat of claim 1, wherein the first batch of raw materials comprises a first colorant and the second batch of raw materials comprises a second colorant that is different that the first colorant.

9. The foam mat of claim 1, wherein the first layer comprises a first texture and the second layer comprises a second texture that is different than the first texture.

10. The foam mat of claim 1 wherein the interlocking peripheral wall comprises a plurality of alternating teeth and receiving slots.

11. A method of manufacturing a foam mat comprising a first layer and a second layer, the method comprising the steps of: (i) separately heating and mixing a first batch of raw materials and a second batch of raw materials at a temperature that is below a foaming temperature of the first batch of raw materials and the second batch of raw materials, respectively; wherein the first batch of raw materials comprises a first polymer, a second polymer, and a colorant; and wherein the second batch of raw materials comprises the first polymer, the second polymer, and a second colorant; (ii) separately heating and pressing the first batch of raw materials and the second batch of raw materials through rollers that are maintained within uniform temperatures of a range of 5 C. to form a first plurality of sheets and a second plurality of sheets, respectively; and (iii) stacking, pressing, and heating one or more of the first plurality of sheets and one or more of the second plurality of sheets to a temperature that permits the sheets to foam and expand; and (iv) cutting a plurality of alternating teeth and receiving slots around a peripheral wall of the mat.

12. The method of claim 11 wherein the first polymer has a first rate of foaming and the second polymer has a second rate of foaming that is different than the first rate of foaming.

13. The method of claim 11 wherein the first polymer has a first rate of expansion and the second polymer has a second rate of expansion that is different than the first rate of expansion.

14. The method of claim 11 wherein the step of stacking, pressing, and heating one or more of the first plurality of sheets and one or more of the second plurality of sheets comprises stacking the sheets in a press.

15. The method of claim 14 wherein the press comprises a top plate and a bottom tray.

16. The method of claim 15 wherein the bottom tray comprises a first die having a first texture.

17. The method of claim 16 wherein the top place comprises a second die having a second texture that is different than the first texture.

18. The method of claim 11 wherein the step of stacking, pressing, and heating one or more of the first plurality of sheets and one or more of the second plurality of sheets comprises stacking three or more of the first plurality of sheets and three or more of the second plurality of sheets.

19. The method of claim 11 wherein the first plurality of sheets and the second plurality of sheets have a uniform thickness.

20. The method of claim 11 wherein the first plurality of sheets and the second plurality of sheets have a thickness between 5 to 10 millimeters.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 is a top plan view of the floor mat of the present invention;

[0012] FIG. 2 shows an embossed design on the top surface of the floor mat of FIG. 1;

[0013] FIG. 2a shows an alternative embodiment of an embossed design on the top surface of the floor mat of FIG. 1;

[0014] FIG. 2b is another embodiment of a design embossed in the top surface of the floor mat of FIG. 1;

[0015] FIG. 3 is a bottom plan view of the floor mat of FIG. 1;

[0016] FIG. 4 shows another design embossed in the surface of the floor mat of FIG. 3;

[0017] FIG. 5 shows a side view of the floor mat of FIG. 1; and

[0018] FIG. 6 is an enlargement of the side view of FIG. 5 in the encircled area labeled FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

[0019] Referring to FIGS. 1 and 3, the floor mat 10 is a large, planar, flat, body 12 which has a first surface 16A and a second opposing parallel surface 16B. The two surfaces 16A and 16B are parallel to one another. The periphery of the floor mat is bounded by an interlocking perimeter 26, which comprises a series of teeth 28A and receiving slots 30A in alternating positions. Interlocking perimeter 26 also comprises four corners each having a smaller tooth 28B and a smaller receiving slot 30B. The surface 16A has a texture or three dimensional design 18 and the second surface 16B has a texture or three dimensional design 18, the two textures or designs can be the same or different. For purposes of this invention, texture means a three dimensional texture or design embossed in or embossed out of the mat surface. One or both surfaces 16A and 16B can also be smooth. The body is made up of two layers 14A and 14B (see FIG. 6). The two layers are bound together either by heat welding and/or an adhesive. Preferably, the two layers have the same chemical composition so that the two layers have the same coefficient of thermal expansion and the same elastomeric properties so that the two layers work together and respond similarly when subject to temperature changes and forces. The two layers have an outer surface 16A and 16B, respectively, and two inner surfaces 17A and 17B which preferably form an undulating boundary 20 between the two layers. Preferably, the inner surfaces 17A and 17B are not parallel to the first and second surfaces. Rather, the two inner surfaces 17A and 17B in the preferred embodiment meet to form undulating boundary 20 which has a topography of rolling hills and vales. The two outer surfaces 16A and 16B are parallel, or generally parallel. In the preferred embodiment, the inner surfaces 17A and 17B are generally not parallel to either of the outer surfaces. Thus, the thickness 22 of the body is generally constant across the entire length and width of the body. In contrast, in the preferred embodiment, the thicknesses of the first layer and second layer vary as the boundary undulates. Thus, the thickness of the first and second layers vary from point to point. The thickness 24A of the first layer 14A at a given point, together with the thickness 24B of the second layer at the same point are equivalent to the thickness 22 of the body. Thus, thickness 24C of the first layer 14A, at a second point, is less than the thickness 24A at the first point and the thickness 24D of the second layer 14B at the second point is greater than the thickness 24B of the second layer at the first point. The undulating boundary between the first layer and the second layer resists delamination of the two layers making the mats more robust as explained supra. However, the two layers 14A and 14B can be flat planar layers of the same or different thickness, each having a generally uniform thickness.

[0020] As described above, the texture of the first surface 16A can be different than the texture of the second surface 16B (see FIGS. 2, 2a, 2b, and 4 showing textures 18A, 18B, 18C and 18D, respectively). Similarly, the color of the first layer and the first surface 16A can be different than the color of the second layer 14B. Thus, the present mats give the purchaser the opportunity to have a selection of colors and/or a selection of textures. In addition, it permits the purchaser to form a checkerboard pattern or other pattern, assuming enough tiles are utilized, utilizing the different textures and/or colors of the mat tiles.

[0021] Preferably, the mats are made from resilient polymeric materials, such as natural or synthetic rubber, and most preferably from foam elastomeric material, such as polyethylene foam, polyurethane foam, EVA-PE foam (ethylene vinyl acetate-polyethylene foam elastomer), and EVA foam (ethylene vinyl acetate foam).

[0022] Preferably, the elastomeric mats are made from a combination of virgin polymer and recycle polymer, such as virgin EVA polymer and a mix of virgin and recycle PE (polyethylene) polymer. The blend of EVA and virgin and recycle PE are compounded together and heated to a temperature below the polymer foaming temperature and pressed into thin sheets through rollers of uniform thickness within uniform temperatures of a range of 5 C.; preferably within a range of 1 C. The sheets are 5 to 10 millimeters in thickness. Other thicknesses can be employed. The sheets are sandwiched together, normally about six sheets to each mat and placed in trays having a bottom surface with a die or mold for the texture and a top plate. The top plate may also have a die or mold for the texture for the other surface. The tray with the sandwich of layers of the raw composition and the top plate are pressed in a press and heated to a temperature to permit the elastomer to foam and expand. The press is required to keep the distance between the tray and the top plate constant to yield elastomeric foam mat of a predetermined thickness. Preferably, the three like sheets have virtually identical compositions and blend together to form one layer of the mat. The two mat layers may have slightly different compositions because their respective sheets are made from different raw compositions (the differences can be slight) at different times (e.g., in different batches).

[0023] The virgin PE and the recycle PE have different rates of thermal expansion and different rates of foaming. The raw compositions of the sheets are restricted in vertical movement and unrestricted in horizontal movement between the tray and the top plate in the press when heated. In the preferred embodiment, three layers of the raw composition will have one color and the other three layers of composition will have another color. Thus, one side of the mat may be red and the other side may be black, etc. The die in the bottom of the tray places one texture on one surface of the mat, and if the top plate has a die, it places a texture on the other surface of the mat. Preferably, the two textures are different although they can be the same. After the foaming reaction is completed by the heating in the press, the tray and the top plate are removed from the press and the unfinished mat is removed from the tray. The mat is allowed to cool and then it is passed to a cutting machine wherein the mat with the interlocking periphery is cut out of the unfinished mat. The mat is now complete.

[0024] In those cases where the top plate does not have a die for the texture, the mat comes out of the press with a texture only on one surface and a smooth planar other surface. The mat can be sent to a roller mill having a cool roller and a heated roller with a die attached thereto. The heated roller with die only heats the surface not having a texture permitting the heated roller with die to texture the other surface of the mat. The textured surface is kept cool by the cool roller. The mat is passed between two rollers and the roller that touches the texture surface is cool, whereas the roller with the die to give texture to the other surface is hot. The cooling roller prevents destruction or damage to the textured surface created in the press.

[0025] The above invention is not restricted to the specific embodiments disclosed herein; modifications and other embodiments of the invention are within the scope of the invention.