Safety Surface Materials

Abstract

A safety surface material for a playground facility employing a monolithically mixed and trowelable thermoplastic olefin urethane cushion base course layer—which, for water park/spray park use is overlain by a thermoplastic rubber wear top course layer that is both light stable and chlorine resistant.

Claims

1. A recreational facility substrate surfacing material comprising: a cushion base course layer and an overlying wear course layer, wherein the cushion base course layer is characterized by having a chemical resistance to acids, bases and aqueous media, and exhibits a combination of stiffness, impact resistance and dimensional stability.

2. The surfacing material of claim 1 wherein the wear course layer is composed of rubber or synthetic turf.

3. The surfacing material of claim 1 wherein said cushion base course layer is a thermoplastic olefin.

4. The surfacing material of claim 2 wherein the cushion base course layer is a thermoplastic olefin.

5. The surfacing material of claim 1 wherein said wear course layer is characterized by having excellent abrasion and weather resistance and dimensional stability, is light weight, non-shrinkable and exhibits a meaningful tear strength.

6. The surfacing material of claim 5 wherein the wear course layer is also ultraviolet light and chlorine resistant.

7. The surfacing material of claim 6 wherein said cushion base course layer is a thermoplastic olefin.

8. The surfacing material of claim 6 wherein said wear course layer is a thermoplastic rubber.

9. The surfacing material of claim 7 wherein said wear course layer is a thermoplastic rubber.

10. The surfacing material of claim 9 wherein said cushion base course layer is of a thickness of 2½″-4″.

11. The surfacing material of claim 9 wherein said wear course layer is of a thickness ⅜″-½″.

12. The surfacing material of claim 10 wherein said wear course layer is of a thickness ⅜″-½″.

13. The surfacing material of claim 12 wherein each of said cushion base course layer and said overlying wear course layer are monolithically trowelable.

14. The surfacing material of claim 1 wherein said cushion base course layer is a thermoplastic olefin with a urethan binder.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0019] FIG. 1 is a block diagram helpful in an understanding of the safety surface materials of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0020] As will be appreciated, one of the more developing recreational facilities of late has been the construction of water parks—and particularly water spray parks in large facilities likened in size to commercial malls. Recognizing that some things other than bare concrete is needed on which kids and children run about, EPDM layers have been proposed, and are being utilized, instead as a covering material. Problems with these granulated synthetic rubber surfaces have been recognized, however, as in US Patent Application Publication 2005/0245681—which proposed instead a formulation termed “Pebble-Flex” as an alternative usage. As its name implies, however, the formulation employed a composition in the form of “pebbles” which by their rounded-type appearance provided a limited ability to join in contact with one another. As a result, its advantages diminished over time, permitting sliding and hydroplaning as the kids and children ran about, especially when the surfacings were very wet.

[0021] Appreciating, furthermore, the need to maintain the active surface as being light stable, unaffected by ultraviolet light, as well as chlorine resistant, it goes without saying that any substitute surfacing exhibiting these characteristics, should also not degrade or readily break off, but have a meaningful life.

[0022] Forward thinking, as with the present invention, led to the conclusion that overall protection should be had, more than just dealing with such minor matters as bruised and scraped bodies, alms and legs when sliding or falling. Although recognizing that ASTM type standards have not so far been determined to apply to water and spray park operations, the present invention proceeds upon the benefits of these standards being satisfied as well.

[0023] Thus, in accordance with the present invention, a new and improved cushion based course layer is developed for use both at playgrounds and at water parks and spray parks. Such layer consists of a thermoplastic foamed thermoplastic olefin, mixed with a urethane binder. By becoming a foamed monolithic surface which is trowelable, one advantage of it is that it does not shrink over time; another is that it is not needed to be put down in individual mats which can later sift and crack at their seams—and thus does not suffer those disadvantages of the prior art. Additionally, a comparable degree of protection as with Styrene Butylene Rubber is provided, yet with a thinner layered surface in a significant cost savings. (An SBR cushion for an HIC of 1000 with a G-Force of 200 that meets American Society For Testing and Materials Standards requires a 3″ cushion. With the thermoplastic olefin urethane composition of the invention, only a 2½″ thickness is required. For a 10,000 square foot playground, for example, a measurable savings of costs can thus be realized. Whereas urethanes when wet deteriorate over time because the water creates an acid base that attacks the polymer chain, in that the surface holds water for months and does not dry out, the thermoplastic foam urethane of the invention does not suffer that disadvantage. Conversely stated, a 3″ thick course layer of the invention would satisfy the ASTM standards for an 8½′ drop whereas a SBR layer would have to be 4″ thick. And because the thermoplastic olefin urethane layer of the invention does not present the same polymer chain that is present with urethane itself, it is not subject to the same acid base that is absorbed even with drying out rain water which creates the degradation of the cushion.

[0024] An installation for the playground operation according to the invention, uses the thermoplastic foam cushion base employed as a combination of a foamed thermoplastic olefin, urethane, polyethylene and/or polypropylene ground into small granules which are mixed in a mixer with a liquid urethane, either aromatic or aliphatic. It is then poured out and leveled on to a substrate, and then hand troweled smooth. Once it cures enough to walk on, usually the next day, the wear course layer can be applied. Preferably, the thermoplastic foam cushion base components are ground into granules some 1-3 mm in size—with the underlying substrate sometimes being in the nature of a stone dust or asphalt itself. Although an aromatic urethane is not light stable, when used in this manner under the wear layer of the invention, no difference results as the light does not penetrate to the thermoplastic foamed cushion base to begin with. Being that the base particles are held together by a resin, epoxies or acylics could be used as well.

[0025] And with the present invention, any rubber or synthetic turf could be installed over it as the wear course layer and the advantages and benefits of this part of the invention are thereby enjoyed.

[0026] Further, in accordance with the invention, a new and improved wear course layer is employed for the alternative recreational water park/spray park facility uses. This layer consists of a thermoplastic rubber, part of the Styrene Elastomer family having both the characteristics of rubber and plastic. For these uses, their characteristic of good tear strength, dimensional stability, weather resistance, reusability and recyclability are highly desirable—along with their being colorable, non-shrinkable, of light weight, ultraviolet light resistant—and of major importance, chlorine resistant for its employment at these water recreational locales.

[0027] Once the thermoplastic olefin foam cushion base has cured enough to walk on, usually the next day, this wear course of colorable rubber is applied on to the base in about ⅜″ to ½″ thickness, and then troweled smooth. The resultant safety surface material of the invention in this respect is all seamless, with the binder holding everything together in one continuous carpet-like setting. A hard surface singular mass results, with the moisture in the air finishing the reaction. The result is a totally seamless surface—which could even be used as a base for synthetic turf as at an athletic stadium. And, to install at an existing site—whether it be a playground, a swimming pool or a spray park—all that becomes necessary is to trowel the base cushion down, and when it is cured, layering it over with the thermoplastic rubber wear layer—whether the substrate underneath be of a stone base, asphalt or concrete composition.

[0028] These features of the invention are illustrated by the Block Diagram of FIG. 1, showing the thermoplastic foamed cushion base combination of thermoplastic olefin, urethane, polyethylene and/or polypropylene 10 ground up into small granules 12 and mixed with a liquid urethane either aromatic or aliphatic. The base layer is then covered with the thermoplastic rubber 14 that is light stable and mixed with an aliphatic chlorine resistant liquid urethane for water park/spray park use—instead of an EPDM wear layer or other thermoplastic vulcanized layer as might be used at a playground although providing less beneficial results there, or with an appropriate artificial surface for soccer, football, or rugby type fields.

[0029] While there have been described what are considered to be preferred embodiments of the present invention, it will readily be appreciated by those skilled in the art that modifications can be made without departing from the scope of the teachings herein. Thus, whereas a 2½″ thickness of the thermoplastic olefin urethane foamed material will satisfy the same ASTM standards as met by a 3″ thickness of the prior art's Styrene Butylene Rubber, different thickness may be required in the future as equipments and/or uses grow in height or activity; similarly, while the thermoplastic rubber wear layer for water park usage is presently believed sufficient of a ⅜″-½″ layer, so, too, would those thicknesses be increased for more strenuous activities at water park locations other than just running around under spray-type equipment and apparatus. For at least such reasons, therefore, resort should be had to the claims appended hereto for a true understanding of the invention.