Patent Application
20110308002
The present invention relates to a durable, plasticizer-free recyclable swimming pool cover.
Many swimming pool covers currently on the market include polyvinyl chloride (PVC). Environmentally harmful plasticizers, such as dioxin, are produced when PVC is incinerated and plasticizers may also leach into the swimming pool water when PVC is used as a swimming pool cover. PVC-containing swimming pool covers generally include plasticizers that become brittle and leach into the water due to sun damage resulting in loss of strength of the swimming pool cover. Currently, it is not technically or economically feasible to recycle PVC-reinforced pool cover materials.
A product life cycle starts with a design phase where the functional specifications are defined as well as the cost constraints. Materials are shipped to the factory which manufactures the product. Marketing and promotion create a demand for the product which then translates into sales for a successful product. The product is then purchased by a customer to whom a finished product is then shipped or is picked up by the buyer. What follows is hopefully a long satisfying service life. After a service period, the pool cover is usually replaced. The final part of the product life-cycle is concerned with discarding or recycling of the product after it has served its service life. A swimming pool cover is considerably large in size and heavy in weight.
Swimming pool covers can generally be categorized into one of two types: mesh pool covers and solid laminate pool covers. While mesh pool covers including recyclable polypropylene are known, the open weave structure of the mesh pool covers allows sunlight to get through and promotes the growth of algae in swimming pool water. What is lacking is a swimming pool cover, which combines the lightweight feature of the mesh pool cover, while it is 100% recyclable but which, unlike conventional mesh pool covers, has minimal maintenance by the fact that it reduces algae growth caused by sunlight penetration through a typical mesh swimming pool cover. Polypropylene is a 100 percent recyclable material. However, if part of a pool cover is made of polypropylene and part is made of a different material, such as a co-polymer including PVC, the polypropylene bonds to the other material and cannot be extracted for recycling. While polypropylene does not emit contaminants such as plasticizers when burnt, it cannot be recycled if bonded to other plasticizer-containing products.
Additionally maintenance costs are associated with PVC-containing swimming pool covers in that they are known to become depressed by puddles of water. This permanent depression of solid laminate PVC covers adds to the maintenance costs in that water must be continuously pumped from the swimming pool cover or expensive drains are installed. The installed drains may further increase maintenance costs should they become clogged.
The present invention is directed to a swimming pool cover formed from a fabric covering and reinforcing and attachment straps. The fabric covering is a polypropylene coated fabric of polypropylene multi-filament fiber. The reinforcing and attachment straps are also polypropylene. The reinforcing and attachment straps are connected to the fabric covering in a criss-crossed pattern. The fabric covering and reinforcing and attachment straps are produced only from polypropylene such that the pool cover is plasticizer-free and does not emit any dioxins when burned. In a preferred embodiment, the fabric includes a polypropylene multi-filament fiber sandwiched between a top layer of polypropylene and a bottom layer of polypropylene. Because the various components of the pool cover are formed only from polypropylene, the pool cover is easily recyclable.
The present invention can best be understood in connection with the accompanying drawings. It is noted that the invention is not limited to the precise embodiments shown in drawings, in which:
In one embodiment of the present invention, the fabric covering 3 is a polypropylene, such as, in one example, known in the trade as Greentex™) material supplied by Fabinno Company. The fabric covering 3 is significantly stronger than that of the currently used PVC pool covers, is approximately 10% lighter (oz./sq. yd.), has lower cost, and has a soft hand feel similar to polyvinyl chloride (PVC) fabric. While the strength and the lightness enhance the service life aspects, the fabric covering material is totally polypropylene, which means that it is entirely plasticizer free and completely and easily recyclable, thereby enhancing the final product life-cycle stage.
Performance testing of the fabric material used in this invention has yielded the following results: (Ultra-Loc® is the prior art fabric while Ultra-Loc II™ is the fabric of this invention. Ultra-Loc® and Ultra-Loc II™ are trademarks of Applicant's assignee Pool Cover Corporation.)
Other factors relating to the use of the Ultra-Loc II™ polypropylene fabric material also enhance life cycle of the swimming pool cover. The lower pool cover weight saves transport fuel and carbon based emissions. The lower weight and improved hand feel also makes the cover easier to handle to install and remove. The polypropylene fabric material has more “bounce” and faster recovery which elevates pockets; this makes it easier to shed any water that had accumulated. Ultra-Loc II™ is virtually opaque blocking sunlight which sunlight tends to support the formation of algae. Therefore algae growth in the swimming pool water is inhibited.
The swimming pool cover 1 in accordance with the present invention has a “rebound” effect when the polypropylene material is temporarily depressed by puddles of water, which, when evaporated, allows the polypropylene-based swimming pool cover to rebound back to its original shape without a bulge. This “rebound” feature will minimize the maintenance required for the swimming pool cover.
In the foregoing description, certain terms and visual depictions are used to illustrate the preferred embodiment. However, no unnecessary limitations are to be construed by the terms used or illustrations depicted, beyond what is shown in the prior art, since the terms and illustrations are exemplary only, and are not meant to limit the scope of the present invention.
It is further known that other modifications may be made to the present invention, without departing the scope of the invention, as noted in the appended Claims.
