Abstract:
An expandable liquid barrier having an expandable layer attached to an adhesive layer is disclosed. The barrier provides constant containment without restricting access or creating a hazard in an area. The barrier is generally low profile like a length of tape until contacted by a liquid. Once in contact with a liquid the barrier expands and provides containment of the liquid. One means for expanding the barrier in the presence of liquid is to provide an expandable fill, such as super absorbent polymer, between the layers. Other means for releasing expanding the barrier include using a water-soluble adhesive to hold a resilient expanding layer and providing contracting section which increases the profile of the barrier. The barrier may be used in combination with a switch to enable reaction to the spill.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/779,350, filed Mar. 3, 2006, which is herein incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to containment and barriers for liquid spills. 
       BACKGROUND INFORMATION 
       [0003]    Curbs, barriers and berms often serve as containment for spilled liquids. These structures are often arranged to contain a liquid within the barrier or divert a liquid away to a more desirable location. Often the barriers are temporarily installed and removed when no longer needed. However, permanent structures are sometimes used where a recurring need exists. 
         [0004]    Temporary barriers, such as berms, dykes or absorbent socks, can contain a spill or leak but must be installed to do so. Often it is the case that the leak or spill has occurred uncontained for some time before the temporary barriers are installed. This creates a much larger spill than would have occurred with a permanently installed barrier. Permanently installed barriers adequately provide constant containment. However, the permanent barriers also constantly project upward from the floor. This arrangement is usually undesirable because these structures create a trip hazard. Furthermore, the structures often create an impediment to wheeled traffic. 
         [0005]    The present invention has been developed in view of the foregoing. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention provides an expandable liquid barrier having an expandable layer attached to an adhesive layer. The barrier provides constant containment without restricting access or creating a hazard in an area. The barrier is generally low profile, like a length of tape, until contacted by a liquid. Once in contact with a liquid the barrier expands and provides containment of the liquid. One means for expanding the barrier in the presence of liquid is to provide an expandable fill, such as super absorbent polymer, between the layers. Other means for releasing expanding the barrier include using a water-soluble adhesive to hold a resilient expanding layer and providing contracting section which increases the profile of the barrier. The barrier may be used in combination with a switch to enable reaction to the spill. 
         [0007]    One aspect of the present invention provides an expandable liquid barrier comprising an adhesive layer attached to a base surface, an expanding layer attached to the adhesive layer and an expandable fill disposed between the adhesive layer and the expanding layer, wherein liquid contact with the expandable fill causes the expandable fill to swell. 
         [0008]    Another aspect of the present invention provides an expandable liquid barrier comprising an adhesive layer attached to a base surface, an expanding layer attached to the adhesive layer comprising a resilient material and soluble adhesive, the expanding layer folded upon itself and restrained in a low profile position by the water-soluble adhesive, whereby liquid contact with the barrier causes the soluble adhesive to dissolve releasing the resilient expanding layer. 
         [0009]    Another aspect of the present invention provides an expandable liquid barrier comprising an adhesive layer attached to a base surface, a contracting section connected to the adhesive layer and adjacent the base surface, an expanding layer attached to the contracting section, whereby liquid contact with the contracting section causes the contracting section to shrink which bends and increases the profile of the expanding layer. 
         [0010]    Another aspect of the present invention provides an expandable liquid barrier comprising an adhesive layer attached to a base surface, an expanding layer attached to the adhesive layer and means for expanding and heightening the barrier when the barrier is contacted by a liquid. 
         [0011]    Another aspect of the present invention provides a method for containing a leaking or spilled liquid comprising the steps of providing an expandable, low profile barrier which expands upon contact with the spilled or leaking liquid and affixing the expandable, low profile barrier to a base surface. 
         [0012]    These and other aspects will become more apparent from the following description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIGS. 1A and 1B  illustrate a perspective view of an expanding liquid barrier according to one embodiment of the present invention showing the low profile configuration of the barrier when liquid is not present and the expanded configuration when liquid contacts the barrier. 
           [0014]      FIGS. 2A and 2B  illustrate a cross-section of an expanding liquid barrier according to one embodiment of the present invention showing the adhesive layer, expanding layer and expanding fill. 
           [0015]      FIG. 3  illustrates a top view of an expanding liquid barrier according to one embodiment of the present invention showing the front and rear longitudinal edges and the permeable and impermeable sections of the expanding layer wherein apertures are provided to create permeability. 
           [0016]      FIG. 4  illustrate a top view of an expanding liquid barrier according to another embodiment of the present invention showing the front and rear longitudinal edges and the permeable and impermeable sections of the expanding layer wherein the permeable section liquid pervious without apertures. 
           [0017]      FIG. 5A  illustrates a top view of an expanding liquid barrier according to one embodiment of the present wherein the expanding layer is affixed to the adhesive layer at the rear longitudinal edge and the barrier is open at the front longitudinal edge. 
           [0018]      FIG. 5B  illustrates a front view of the barrier shown in  FIG. 5A  further showing the expandable fill and flexible members. 
           [0019]      FIG. 5C  illustrates a front view of the barrier shown in  FIG. 5B  showing the barrier&#39;s configuration when liquid is present. 
           [0020]      FIG. 5D  illustrates a side view of the barrier shown in  FIG. 5C . 
           [0021]      FIG. 6A  illustrates illustrate a cross-section of an expanding liquid barrier according to one embodiment of the present invention having a resilient expanding layer held in a low profile position by water soluble absorbent. 
           [0022]      FIG. 6B  illustrates the barrier of  6 A when liquid is present. 
           [0023]      FIGS. 7A and 7B  illustrate a cross-section of an expanding liquid barrier having a contracting section which increases the profile of the expanding section when liquid is present according to one embodiment of the present invention. 
           [0024]      FIGS. 8A and 8B  illustrates a cross-section of an expanding liquid barrier used in combination with a switch according to one embodiment of the present invention. 
           [0025]      FIG. 9  illustrates how the expandable liquid barrier may serve to divert a liquid to a receptacle or drain. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    Referring now to  FIG. 1A , an expanding liquid barrier  1  is shown according to one embodiment of the present invention. The expanding liquid barrier  1  is substantially flat and low profile when no liquid is present. The barrier  1  preferably has tape-like or narrow sheet-like geometry. When liquid  2  contacts the barrier  1 , the barrier  1  heightens to create a barrier  1  or dyke as shown in  FIG. 1B . 
         [0027]    According to one embodiment of the present invention shown if  FIGS. 2A and 2B , the barrier  1  may include an adhesive layer  10  which holds the barrier to a base surface  3 . The base surface  3  may be any surface which may benefit from a barrier of this type, for example, a floor, walkway, entranceway, lab table, equipment platform or other surface. In one embodiment the adhesive layer  10  is a one-sided tape. The adhesive layer  10  has a bottom face  11  and a top face  12 . The bottom face  11  is adhered to the base surface  3 . The bottom face  11  of adhesive layer  10  prevents horizontal and vertical movement of the barrier  1 . The bottom face  11  also creates a seal preventing liquid from passing under the barrier  1 . The top face  12  is opposite the bottom face on the adhesive layer and is connected to an expanding layer  20 . The expanding layer  20  is affixed to the top surface  12  of the adhesive layer  10  along a longitudinal edge of the barrier at a front end  5  and rear end  6 . The expanding layer  20  may be affixed to the adhesive layer  10  by adhesive or by mechanical seal. The expanding layer  20  may be made of two or more sections, a liquid permeable section  40  and liquid impermeable section  30 . The impermeable layer  30  may be made from any liquid impervious material, for example, vinyl, rubber, Acrylonitrile butadiene styrene (ABS), materials found under the tradename Sanoprene, polyethylene and polypropylene. The permeable section  40  may be made of perforated sheet and solid materials and woven and non-woven materials. The permeable layer  40  may be made from a material which allows fluid to pass through like a woven material or the liquid permeable layer  40  may be what is considered an impermeable material with various holes throughout the segment to allow liquid to pass as seen in  FIG. 3 . 
         [0028]    Again referring to  FIGS. 2A and 2B , an expandable fill  50  may be disposed between the adhesive layer  10  and the expanding layer  20 . The expandable fill  50  is capable of increasing in size or swelling when it comes in contact with a liquid. As the expandable fill  50  swells the expanding layer  20  fills and increases in height. The expandable fill  50  may also absorb some amount of liquid. In one embodiment the expandable fill is a super absorbent polymer. In another embodiment the expandable fill  50  may comprise compressed sponges, foam or any other compressible absorbent. For example, Isocyanate-Based foams, Pyranyl foams, Syntactic foams, and/or Elastomeric foams may be used. Certain absorbents may be compressed through the use of a water-soluble binder, i.e. the absorbent may be wetted with the binder compressed and dried into a thin configuration. 
         [0029]    Referring now to  FIG. 3 , a section of barrier  1  is shown. The arrow indicates the direction from which liquid would approach the barrier  1 . In a preferred orientation, the permeable section  40  is positioned nearest the approach of the fluid. In this embodiment, permeable section  40  is typically made from the same material as impermeable section  30 . The permeable section  40  allows fluid to pass by way of apertures  41 . 
         [0030]    Referring now to  FIG. 4 , the same preferred arrangement is shown with the permeable section nearest the approach of fluid. However, in this embodiment, the permeable section  40  and impermeable section  30  comprise different materials. The impermeable section  30  comprising a material impervious to the flow of liquid while the permeable section  40  utilizes and inherently permeable material to allow liquid to pass. The impermeable section  30  and permeable section  40  are joined by any common means. 
         [0031]    In the embodiment shown in  FIGS. 5A-5D , the barrier  1  includes an adhesive layer  10  affixed at one end to an expanding layer  20 . The expanding layer  20  includes only an impermeable section  30 . The expanding layer  20  and adhesive layer  10  open at one end but are connected by flexible members  21 . The flexible members  21  allow the expanding layer to open partially but not fully. For example, the flexible members  21  may restrict opening of the expanding layer  20  to less than 90°. As seen in  FIG. 5B  expandable fill  50  is disposed between the expanding layer  20  and adhesive layer  10 . The expandable fill  50  swells when in contact with a liquid causing the expanding layer  20  to lift at its open end. The expanding layer  20  raises until the flexible members  21  are fully extended, as shown in  FIG. 5C  and  FIG. 5D . Flexible members  21  may be made of any suitable material, which is flexible yet, substantially inelastic. 
         [0032]    Another embodiment of an expanding liquid barrier according to the present invention is shown in  FIGS. 6A and 6B . In this embodiment the barrier  1  has an adhesive layer  10  affixed to the floor and an expanding layer  20 . The expanding layer  20  is made of an impermeable and highly resilient material, for example, rubber, ABS, materials found under the tradename Sanoprene, polyethylene, and polypropylene. As seen in  FIG. 6A , the expandable layer  20  is held in a generally flat and low profile configuration by being compressed and held together with a water-soluble adhesive  22 . When a water based liquid  2  comes into contact with the barrier  1  the water soluble adhesive  22  dissolves and releases the expanding layer so that the liquid may be contained as seen in  FIG. 6B . The water soluble adhesive  22  may be, for example, cellulose ether, polyvinylpyrrolidone, or polyvinyl alcohol. It is also contemplated that the soluble adhesive  22  may be oil based where the barrier  1  is used to contain oil based liquids. Suitable oil soluble adhesives include, for example, Ethoxylated nonylphenol and Transitions metal alkyl sulfonates. 
         [0033]    Referring now to  FIGS. 7A and 7B , an expanding liquid barrier  1  according to one embodiment of the present invention is shown. In this embodiment, the barrier  1  has an adhesive layer  10  affixed to the floor. Adjacent the adhesive layer  10  is a contracting portion  25  also adjacent the floor. The expanding layer  20  is affixed at its ends to the contracting portion  25  as shown in  FIG. 7A . In one embodiment the expanding layer  20  may have a front end attached to the contract section  25  and a rear end attached to the adhesive layer  10 . The expanding layer  20  may be wholly made of liquid impermeable material or may have a portion which is permeable nearest the approach of the liquid  2  to be contained. When liquid  2  comes into contact with the contracting portion  25 , the contracting portion  25  shrinks along dimension D is shown in  FIGS. 7A and 7B . As the contracting portion  25  decreases along dimension D, the expanding layer  20  raises to contain the liquid  2  as shown in  FIG. 7B . 
         [0034]    Referring now to  FIGS. 8A and 8B , a switch  60  may be incorporated with the barrier  1 . The switch may be mounted so that the switch  60  is in one position when no liquid  2  is present and the barrier  1  is in a substantially flat arrangement. When liquid  2  is present the barrier  1  expands and activates the switch  60  as shown in  FIG. 8B . The expanding barrier  1  and associated activation of switch  60  may send a signal to an alarm such as an audible alarm, beacon, strobe light or other indicator to alert personnel that a leak has been detected. It is also contemplated that the switch  60  could be tied into other equipment such as automatic valves, pumps, etc to stop the flow of liquid. This communication may be direct or through a computer or PLC. While the switch  60  shown in  FIGS. 8A and 8B  is a standard limit switch affixed with a metal lever  61  and wheel  62 , it is contemplated that the switch  60  may be of any type suitable for this application. For example, the switch  60  could be a plunger type, proximity switch or other suitable switch. 
         [0035]    Referring now to  FIG. 9 , a beneficial aspect of the present invention is illustrated. While it should be apparent that the expanding barrier  1  may provide containment it should also be appreciated that the barrier  1  may also be used as a diverter of liquid. The expanding barrier may be installed around a container  70  or other spill source, such as piping or equipment. Under normal conditions the barrier  1  is low profile and not an obstacle or impediment to pedestrian or wheeled traffic. However, it will be appreciated that should a leak in the container develop, the barrier will expand and divert the liquid to the drain  80  or other receptacle. 
         [0036]    Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims.