Abstract:
A spa shell and method of its manufacture are disclosed, providing a spa shell with improved functional and aesthetic effects. The spa shell includes a transparent layer that is formed into a shape of the spa shell. The spa shell further includes an opaque substrate applied to the transparent layer on the bottom side of the shape of the spa shell.

Description:
BACKGROUND  
       [0001]     This invention relates to preformed water containers, and more particularly to a thermoformed spa or pool shell used for containing water.  
         [0002]     Spa shells are made of a variety of materials that, in addition to practical considerations of sturdiness, water-impermeability, and texture, can be chosen for aesthetic effect. For example, some spa shells include colored acrylic laminated on top of an impact-resistant acrylonitrile butadiene styrene (ABS) plastic substrate to form a unitary sheet having a coarse, granite-like surface. The sheet is then thermoformed into a spa shell. In another example, coloring can be applied to the top surface of a formed spa shell for a particular look or design in the top surface.  
         [0003]     Unfortunately, aesthetic qualities are generally fixed once a laminated sheet has been thermoformed into the spa shell. Further, damage or scratches to the top surface of conventional spa shells can be difficult to repair without adversely affecting of the color and/or “look and feel” of the top surface. Additionally, once formed, a conventional spa shell&#39;s aesthetic or design elements cannot be altered or adjusted to conform to current industrial fashion standards without significant costs, if at all.  
       SUMMARY  
       [0004]     This document discloses a spa shell and method for manufacturing the same, providing unique functional and aesthetic qualities that can be dynamically configured throughout the manufacturing process of a spa. Further, the disclosed spa shell and manufacturing method allows for a spa shell that is resistant to damage or scratches, or which can be repaired easily without altering the general function or appearance of the top surface of the spa shell.  
         [0005]     In an embodiment, a spa shell includes a transparent layer forming a shape of the spa shell. The spa shell further includes an opaque substrate applied to the transparent layer on the bottom side of the shape of the spa shell. Design elements may be provided in the opaque substrate to be visible through the transparent layer. The transparent layer can be slip-resistant and offer protection to the opaque layer, yet still provide a unique aesthetic to the spa shell.  
         [0006]     A method of manufacturing the spa shell includes the steps of forming the transparent layer into a shape of the spa shell, and applying the opaque substrate to one side of the transparent layer corresponding to a bottom side of the shape of the spa shell. The transparent layer can be thermoformed into the shape of the spa shell, and the opaque substrate can be applied according to various application techniques.  
         [0007]     The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     These and other aspects will now be described in detail with reference to the following drawings.  
         [0009]      FIG. 1  is a cross-sectional representation of a spa shell.  
         [0010]      FIG. 2  is a cross-sectional representation of a section of a spa shell.  
         [0011]      FIG. 3  is a flowchart of a method of manufacturing a spa shell. 
     
    
       [0012]     Like reference symbols in the various drawings indicate like elements.  
       DETAILED DESCRIPTION  
       [0013]      FIG. 1  is a cross-sectional diagram of a spa shell  100  having a transparent layer  102  and an opaque substrate  104  applied to the transparent layer  102  at a bottom side  105  of the spa shell  100 , forming an interface  106 . The transparent layer  102  allows the opaque substrate  104  at the interface  106  to be visible from a top side  103  of the spa shell  100 . The terms “bottom” and “top” refer to opposing sides of the spa shell  100  merely in one orientation depicted in  FIG. 1  and indicate opposing sides of a plane, but should not be used to limit the invention in any way. The transparent layer  102  may be completely transparent, or can be translucent such as having a smoked or colored look. The transparent layer  102  can be made of a plastic such as acrylic or an acrylic-based material, or any other transparent or translucent rigid material that can be formed into the shape of the spa shell  100 .  
         [0014]     The opaque substrate  104  is applied to at least a portion of one side of the transparent layer  102  corresponding to the bottom side  105  of the spa shell  100 . The opaque substrate  104  may, but need not necessarily, be applied after the transparent layer  102  is formed into the shape of the spa shell  100 . The opaque substrate  104  provides an aesthetic element at the interface  106  that is visible through the transparent layer  102  from the top side  103  of the spa shell  100 . The aesthetic element can include one or more colors, textures, patterns and/or designs. The opaque substrate  104  can be made of fiberglass, polyurethane, fiberglass reinforced polyester (FPR) or other material that can be suitably applied to the transparent layer  102  such as paint or other coating. In one example, a fiberglass- or polyurethane-based material in a pourable formulation is sprayed or applied as a cast on to the transparent layer  102  that has been pre-formed into the shape of the spa shell  100 . One type of polyurethane material that may be used is known as ACRYLOBOND™, a two-component polyurethane designed specifically as an environmentally friendly alternative to traditional acrylic-backing applications.  
         [0015]     The spa shell  100  may be formed with one or more seat areas  110  to which at least the transparent layer  102  conforms, and one or more apertures  120  for accommodating spa components such as plumbing, jet vents, user controls, filter openings, etc. In one embodiment, a transparent sheet is thermoformed into the shape of the spa shell  100 , including the seat areas  110 , to form the transparent layer  102 . Next, the opaque substrate is sprayed or otherwise applied onto the one side  106  of the transparent layer  102 . Then, the apertures  120  can be formed through one or both of the transparent and opaque substrates  102  and  104 .  
         [0016]     The above described arrangement has several advantages. One advantage is that the transparent layer  102  may be scraped, filed, sanded, filled or polished without touching or harming the aesthetic qualities of the opaque layer  104  or any design element disposed in the opaque layer  104 . Another advantage is the transparent layer  102  can provide a wet or smoky look to the top side  103  of the spa shell  100 : a look that has been previously attainable with a clear sheet laminated to an opaque sheet, and which could not be formed into a spa shell without de-lamination. Still another advantage is a cost savings in inventory or manufacturing associated with the efficiencies of using a pre-shaped spa shell of one transparent or translucent layer with a variety of opaque substrates and design applications. The above described arrangement also allows for greater flexibility in design applications and conformance with changing fashions.  
         [0017]      FIG. 2  is a cross-sectional diagram of a section  101  of the spa shell  100 , such as from a vertical wall section of a spa for example. The section  101  of the spa shell  100  includes a transparent layer  102  and an opaque substrate  104 . The opaque substrate  104  is applied to one side  106  of the transparent layer  102 . The one side  106  of the transparent layer  102  to which the opaque substrate is bonded or applied corresponds to the bottom side  105  of the spa shell  100 . This arrangement allows at least a surface of the opaque substrate  104  at the interface  106 , or any design elements  130  disposed in or proximate with the opaque substrate  104 , can be visible or can extend through the transparent layer  102  from the top side  103  of the spa shell  100 .  
         [0018]     One or more of the design elements  130  can be disposed in the opaque substrate  104 . Design elements  130  include, without limitation, colors, a pattern, a design such as a logo or other artwork, a user interface such as lights or a display, or other design. Design elements  130  can also include functional elements such as plumbing, drains or heater outlets, spa jets, user controls, or the like. One or more of the design elements  130  can extend through the opaque substrate  104  and/or transparent layer  102  via an aperture  120 . Or, one or more design elements  130  can be disposed in the opaque substrate  104  and up against the interface  106 . In either case, the design elements are visible through the transparent layer  102  from the top side  103  of the spa shell  100 .  
         [0019]      FIG. 3  is a flowchart of a method  300  of manufacturing a spa shell. At  302 , a transparent layer is provided that can be completely transparent or have a particular translucence. For example, the transparent layer can be clear, smoked or colored. The transparent layer can be made of a single, smooth sheet of material such as acrylic or other plastic. At  304 , the transparent layer is thermoformed according to any one of a number of conventional thermoforming techniques. The thermoforming of the transparent layer yields a transparent layer in the general shape of the spa shell, at  306 . For instance, the transparent layer can be formed with seats, ridges, grooves, etc., for accommodating various design elements of a finished spa.  
         [0020]     At  308 , an opaque substrate is applied to the bottom of the shaped transparent layer, i.e. the side opposite a surface of the spa shell that will be visible by a user. The opaque substrate can be made of any opaque material that can be suitably applied to the transparent layer such as by spraying or casting. In one embodiment, the opaque substrate is a polyurethane-based material such as ACRYLOBOND™. Other materials may be used for the opaque substrate as well, such as FPR for example.  
         [0021]     At  310 , one or more various design elements can be provided to or disposed in the opaque substrate, such as texture, color, user and/or control interfaces, etc. These design elements will be visible in the opaque substrate through the transparent layer. At  312 , the spa shell can be configured with other functional design elements such as jet outlets, drain holes, control apertures, etc., for accommodating various spa components. These design elements can extend through one or both the transparent layer and opaque substrate, yet will have a visually appealing appearance from a perspective through the transparent layer.  
         [0022]     At  314 , the spa shell can be finished using various techniques such as sanding, filing, cutting, drilling, washing, etc. The finished spa shell is thus prepared for being assembled into a finished spa product. The transparent layer can provide a wet or smoky look, yet still provide traction for a user and be resistant to impacts, water, sunlight, bacteria, and other deleterious hazards. The opaque substrate and design elements provide an aesthetic that is visible through the transparent layer. Dents or cracks in the top surface of the spa shell, i.e. the transparent layer, can be repaired without affecting the aesthetic qualities of the opaque layer and design elements.  
         [0023]     A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. The steps shown in  FIG. 3  need not be completed in the order depicted. For example, the design element may be added at  310  before the opaque substrate is applied at  308 . Accordingly, other embodiments are within the scope of the following claims.