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TECHNICAL FIELD 
       [0001]    The present invention relates to a urinal mat of the type that is placed into a urinal. 
       BACKGROUND ART 
       [0002]    Male urinals typically comprise a receptacle made from ceramics or metal. The urinal typically has a generally vertical wall that extends down to a floor region of the urinal. The floor is fitted with an opening so that urine and flush water can be removed from the urinal. In use of such urinals, a stream of urine impacts on to the wall and/or floor of the urinal and pools in the lower part of the urinal as it drains from the urinal. Flush water may be used to flush out any residual urine. Flush water may be provided by a user manually operating a flush button or by way of periodic automatic flushing. 
         [0003]    In order to address issues of odour and hygiene in male urinals, it has been common practice to place cakes of chemicals in the urinal. Such cakes typically include antiseptic agents and fragrances. The cakes slowly dissolve when they are contacted with urine or flush water. Such cakes typically have a very strong and somewhat unpleasant odour. 
         [0004]    More recent developments have seen the introduction of urinal mats into urinals. Urinal mats typically comprise a plastic mat having a number of holes or apertures therethrough. Such mats may also include upstanding fingers or bristles to reduce or minimise splashing of urine streams that are directed onto the mat. The plastic may be impregnated with a fragrance or perfume that is released when the urinal mat is wetted. In this manner, the fragrance or perfume is released to thereby mask odours. 
         [0005]    Other efforts to address odour and hygiene in male urinals involve the use of blocks containing bacterial products that consume or react with compounds in urine. These bacterial blocks are typically made by mixing bacterial culture(s) with a powdered surfactant and water and pressing the blocks to shape. The blocks are placed into the urinal and when they are wetted by urine or flush water, they start to dissolve to thereby release bacteria into the urinal and the piping associated with the urinal. The bacteria then consume or react with some of the compounds in the urine to thereby improve hygiene. In practice, these bacterial blocks can be rapidly consumed and require frequent replacement. 
         [0006]    It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country. 
       SUMMARY OF INVENTION 
       [0007]    The present invention is directed to an improved urinal mat, which may at least partially overcome at least one of the abovementioned disadvantages or provide the consumer with a useful or commercial choice. 
         [0008]    With the foregoing in view, the present invention in one form, resides broadly in a urinal mat comprising a mat of plastics material, a block containing bacterial material, a housing or cover having an upper portion surrounding an upper part of the block, and a lower surface extending below the block containing bacterial material, the lower surface having one or more openings therein. 
         [0009]    In one embodiment, the upper portion of the housing or cover comprises a closed surface that encloses the upper surface and the sides of the block containing bacterial material. The upper portion of the housing or cover may be made from a water impermeable material. 
         [0010]    In one embodiment, the lower surface extending below the block of bacterial material and/or a lower surface of the mat is provided with feet or legs to space the lower surface from a floor or wall of the urinal. The feet or legs may have a length that falls within the range of from 2 mm to 5 mm, or suitably from 2 mm to 3 mm. 
         [0011]    In some embodiments, the block containing bacterial material is located within a block housing. The block housing may comprise a lower part comprising the lower surface and an upper part comprising one or more closed side walls and a closed upper surface. The upper part and the lower part of the housing may be adapted to be joined together to form the block housing. The block containing bacterial material may be located in the upper part of the block housing and the upper part and the lower part of the block housing subsequently joined together to thereby retaining the block containing bacterial material within the housing. The upper part may comprise the upper portion of the housing or cover. 
         [0012]    In one embodiment, the mat of plastics material is formed with an opening therein that is of complimentary size to a periphery of the lower part of the housing. The lower part of the housing can then be fitted into that opening and thereby connected to or joined to the mat of plastics material. The upper part of the housing may then be joined to the lower part of housing. It will also be appreciated that the upper part and the lower part of the housing may be joined together and then the housing placed into the opening into the plastics that to thereby join the housing to the plastic mat. 
         [0013]    In another aspect, the present invention provides a urinal mat comprising a mat of plastics material and a block containing bacterial material, the block being held in a fixed position relative to the mat of plastics material, a water impermeable cover extending over sides and an upper surface of the block containing bacterial material, the urinal mat further having a lower surface below the block containing bacterial material, the lower surface having one or more apertures therein. 
         [0014]    In some embodiments, the mat of plastics material is impregnated with a fragrance. The fragrance is released when the mat is wetted by urine or flush water. Desirably, the fragrance is present in the plastic mat in an amount of up to 30% by volume. The fragrance may comprise any commercially available fragrance known to be used in urinal mats. 
         [0015]    The mat of plastics material is desirably made from ethylene vinyl acetate (EVA). Using EVA as the sole material from which the plastic mat is made at allows for a high concentration of fragrance to be incorporated into the mat. For example, as indicated above, the fragrance may be incorporated into the EVA mat in an amount of up to 30% by volume. However, it will also be appreciated that the mat of plastic material may be made from any other plastic material known to be suitable for use in the manufacture of urinal mats. 
         [0016]    The block containing bacterial material may comprise any bacteria known to be suitable for the degradation of urine by-products. The block many include aerobic bacteria.  Bacillus  bacteria may be used. The bacteria may include those that produce one or more of the following enzymes: protease, lipase, amylase, cellulose and uriase. They bacteria produce these enzymes to help break down the urine into chemicals which they and other bacteria can digest. The final outcome is that the bacteria reduce the urine to harmless substances such as carbon dioxide and water. 
         [0017]    In some embodiments, the block containing bacterial material may also include one or more enzymes that can help break down urine into chemicals which the bacteria can digest. This allows the urine to rapidly break down and the bacteria to rapidly digest the compounds produced by the enzymatic action. This, in turn, allows for rapid odour reduction. 
         [0018]    The block containing bacterial material also suitably comprises one or more surfactants. When the block is contacted by urine or water, surfactant is released from the block along with bacteria and this assists in having the bacteria coat the entire inner surface of pipes connected to the urinal. In this regard, the surfactant may have a foaming action and the foam may assist in distributing the released bacteria around the inner surface of the pipes. 
         [0019]    The surfactant is suitably a water soluble surfactant. 
         [0020]    In one embodiment of the present invention, the block containing bacterial material includes a solid surfactant. The solid surfactant may comprise a surfactant that is in the solid state at temperatures ranging from −15° C. to +50° C. The surfactant should suitably dissolve at a steady rate in the presence of water or urine to allow for dispersal of the bacteria and the surfactant. 
         [0021]    The block containing bacterial material may be produced by melting the solid surfactant and mixing bacteria into the solid surfactant. This allows the bacteria to be well dispersed through the solid surfactant. Other ingredients, such as fragrances, may also be added to the block. The molten mixture may then be poured into a mould and allowed to cool so that it hardens into a solid block. In some embodiments, the mould may comprise the upper part of the housing or the cover. This is advantageous in that the block containing bacterial material does not need to be ejected from a mould and then positioned in the housing. Suitably, the solid surfactant becomes molten at a temperature that is low enough so that it is not harmful to the bacteria. 
         [0022]    The block containing bacterial material may have bacteria present in an amount that is suitable to achieve the bacterial effects to reduce odours in urinals. In one embodiment, the block may have a bacterial count of from 1×10 7  to 1×10 9  counts per gram, suitably from 1×10 8  to 1×10 9  counts per gram, more suitably from 5×10 8  to 7.5×10 8  counts per gram. It will be appreciated that the present invention encompasses any suitable bacterial concentration in the block. 
         [0023]    In the urinal mat of the present invention, the lower surface beneath the block containing bacterial material has one or more openings therein. In preferred embodiments of the invention, urine and water can only contact the block containing bacterial material through the one or more openings in the lower surface beneath the block. The total area of the openings in the lower surface below is the block may be up to approximately 10% of the area of the lower surface beneath the block, or from approximately 5% to 10% of the area of the lower surface beneath the block. 
         [0024]    Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0025]    Various embodiments of the invention will be described with reference to the following drawings, in which: 
           [0026]      FIG. 1  shows a perspective view from above of a urinal mat in accordance with an embodiment of the present invention; 
           [0027]      FIG. 2  shows a top view of the urinal mat shown in  FIG. 1 ; 
           [0028]      FIG. 3  shows a bottom view of the urinal mat shown in  FIG. 1 ; 
           [0029]      FIG. 4  shows a side view of the urinal mat shown in  FIG. 1 ; 
           [0030]      FIG. 5  shows a top view of the plastic mat used in the urinal mat shown in  FIG. 1 . 
           [0031]    In  FIG. 5 , the central housing that holds the block containing bacterial material has not yet been attached to the mat; 
           [0032]      FIG. 6  shows a perspective view of the lower part of the housing that holds the block containing bacterial material; and 
           [0033]      FIG. 7  shows a perspective view of the housing that holds the block containing bacterial material. In  FIG. 7 , the upper part of the housing has been joined to the lower part of the housing that was shown in  FIG. 6 . 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0034]    It will be appreciated that the drawings have been provided for the purposes of illustrating preferred embodiments of the present invention. Therefore, it will be understood that the present invention should not be considered to be limited solely to the features as shown in the drawings. 
         [0035]      FIGS. 1 to 4  show a completed urinal mat in accordance with a preferred embodiment of the present invention. The urinal mat  10  shown in  FIGS. 1 to 4  comprises a plastic mat  12 . The plastic mat  12  may be made from EVA or other suitable plastic. The mat  12  is flexible, which means it is able to largely conform to the shape of the bottom of the urinal when the urinal mat  10  is placed in the urinal. 
         [0036]    The plastic mat  12  is suitably made from plastic material that is impregnated with a fragrance. The fragrance may be present in the mat in an amount of up to 30% by volume. Using EVA as the plastic allows for such high fragrance concentrations to be attained. The fragrance may be any suitable fragrance known to be used in urinal mats. Examples of suitable fragrances include spiced apple, kiwi grapefruit, cucumber melon and mango. The person skilled in the art will understand that the fragrances are able to volatilise out of the plastic over a period of time. The rate at which the fragrances leave the plastic may increase when the plastic is wetted by urine or flush water. 
         [0037]    The urinal mat  10  also includes a number of projections  14  on its upper surface. These projections extend upwardly and act to reduce splashing when a stream of urine is directed onto the projections. The projections  14  also act to increase the surface area of the plastic mat  12 , which allows for a larger amount of fragrance to be released from the surface of the plastic mat  12 . 
         [0038]    The urinal mat  10  also includes a number of circular openings  16 . Circular openings  16  allow urine that impinges on the top of the urinal mat  10  to flow therethrough, thereby providing for an enhanced drainage of urine from the upper surface of the urinal mat  10 . The urinal mat  10  also includes a number of elongate slots  18 . Slots  18  not only allow for drainage of urine therethrough, they also provide regions at which novelty or promotional items, such as football goalposts or the like, can be mounted to the urinal mat  10 . 
         [0039]    The urinal mat  10  also includes a central housing  25  that holds a block containing bacterial material. As can be seen from  FIG. 1  and  FIG. 4 , the central housing  25  extends upwardly from the plastic mat  12 . 
         [0040]    The plastic mat  12  may be made by moulding. The plastic mat  12  is shown in its&#39; as-formed state in  FIG. 5 . As can be seen from  FIG. 5 , the plastic mat  12  has a large central opening  20 . The central opening  20  allows the housing  25  that holds a block containing bacterial material to be mounted to the plastic mat  12 . 
         [0041]    The housing  25  that is mounted via central opening  20  to the plastic mat  12  is shown in  FIG. 7 . The housing comprises an upper part  22  and a lower part  24 . Lower part  24  is shown in  FIG. 6  separated from the upper part  22 . The upper part  22  of the housing comprises a top surface  26  and a downwardly extending sidewall  28 . An outwardly extending flange  30  extends from the lower part of sidewall  28 . 
         [0042]    The lower part  24  of the housing comprises a base plate  32  having an upwardly extending wall  34 . Upwardly extending wall  34  is spaced inwardly from an outer periphery of base plate  32 . An outwardly extending flange or lip  36  extends from the upper edge of wall  34 . 
         [0043]    The base plate  32  is dimensioned so that it is larger than the opening of central opening  20  in the plastic mat  12 . The upper flange  36  of lower part  24  of the housing is dimensioned such that it can fit through the aperture  20 , although this may require that the opening  20  is slightly stretched as the flange  36  passes therethrough. The upwardly extending wall  34  of the lower part  22  of the housing is dimensioned such that it has an outer diameter that is substantially the same as the diameter of the central opening  20  of the plastic mat  12 . 
         [0044]    The upper part  22  and the lower part  24  may be joined to form the housing  25  by pressing the upper part  22  onto the lower part  24 . In one embodiment, the flange  36  of the lower part  24  engages with the upper part  22  to thereby hold the upper part and the lower part together to form the completed housing. In one embodiment, in order to assemble the urinal mat  10 , the upwardly extending wall  34  of the lower part  24  is pushed through the central opening  20  of the plastic mat  12 . The upper part  22  of the housing is then press fitted onto the lower part  24  of the housing to form the completed housing. The plastic mat  12  is also provided with four openings  38  that receive upwardly extending legs (one of which is shown at  40  in  FIG. 7 ) that extend from the base plate  32  of the lower part  24  of the housing. This positions the base plate  32  relative to the plastic mat  12  and also assists in retaining the lower part  24  of the housing in position. The legs may also be shaped to fit into corresponding apertures in the lower edge of the flange  30  of the upper part  22  of the housing to hold the upper part and lower part together. 
         [0045]    The upper part  22  and the lower part  24  of the housing are press fitted together. This acts to sandwich the part of the mat between the flange  30  and the portion of the base plate  32  that is located directly beneath the flange  30 . This, combined with the legs  40  passing through the openings  38 , securely positions the housing relative to the plastic mat  12  in the completed urinal mat  10 . 
         [0046]    The top surface  26  and sidewall  28  of the upper part  24  of the housing present a closed surface. In one embodiment, the upper part of the housing is made from polypropylene or from another plastic material. As a result, the upper part of the housing (for example, the part of the housing that is visible in  FIG. 1 ) presents a water impermeable surface that does not allow the passage of urine or water therethrough. Urine and water can flow through the circular openings  16  and elongate slots  18  in the plastic mat  12 . However, urine and water cannot flow through the upper part of the central housing of the urinal mat  10 . 
         [0047]    The housing of the urinal mat  10  holds a block containing bacterial material. The bacterial material may comprise aerobic bacteria that can digest compounds in urine and other bacteria that produce enzymes that break down compounds in urine into by-products that can be utilised by the aerobic bacteria. Alternatively, or additionally, the block containing bacterial material may also comprise enzymes. The block containing bacterial material also comprises one or more surfactants. One or more fragrances may also be present. The block containing bacterial material is suitably formed by melting a solid surfactants and mixing in bacterial material, fragrances and enzymes. When the mixture is fully mixed, the mixture is poured into an upturned upper part  22  of the housing and allowed to cool and solidify. Once it has solidified, the upper part  22  of the housing may then be joined to the lower part  24  of the housing, as described above, to form the completed urinal mat  10 . 
         [0048]    The surfactant used in the block containing bacterial material is suitably a solid surfactant that is solid from −15° C. to 50° C. The surfactant may comprise a nonylphenol polyoxyethylene ether, a polyol ester polyoxyethylene ether, an alkyl polyglucoside or mixtures of two or more thereof. The block preferably consists of surfactants, fragrances, bacteria and enzymes only. Suitably, no fillers are used in the block. The surfactant is suitably water-soluble so that it slowly dissolves when it is wetted by urine or flush water. In preferred embodiments, the block contains around 5.9×10 8  counts bacteria per gram. The block may have a weight of approximately 50 g with approximately 2 g of bacterial compound per block. Fragrances may be present in the block in amount of from 5% to 10% by volume. 
         [0049]    As best shown in  FIG. 3 , the base plate  32  of the housing  25  is provided with a plurality of apertures  42 . In particular, in the embodiment shown in  FIG. 3 , base plate  32  is provided with seven apertures  42 . The apertures  42  provide openings through which urine and flush water can pass and come into contact with the block containing bacterial material that is housed within the housing  25 . In this manner, when the urinal is being used, some of the block containing bacterial material dissolves when it is contacted by urine and/or flush water that travels through the apertures  42 . This releases the bacterial material, the fragrances, and the surfactants from the housing  25 . In order to provide for an appropriate release rate of material from the block containing bacterial material, the openings  42  in the base plate  32  may have a total area that is between 5 and 10% of the area of the base of the block of material. The present inventor has found that using this ratio of open area in the base plate to area of the base of the block of material allows for a suitable rate of release of material from the block containing bacterial material whilst also ensuring that the rate of release is not so high that the usable lifetime of the urinal mat  10  is shortened. In some instances, humid air passing through the apertures in coming into contact with the block containing bacterial material may be sufficient to dissolve or release some of the bacterial containing material. 
         [0050]    The urinal mat  10  also includes feet or legs  44  that extend downwardly from a lower surface of the plastic mat  12 . These are clearly shown in  FIGS. 3 and 4 . The feet or legs may have a height of from 2 to 5 mm, preferably from 2 to 3 mm. The feet or legs  44  space the lower surface of the plastic mat  12  from the floor of the urinal, thereby allowing urine and flush water to flow underneath the urinal mat  10 . Urine and/or flush water flowing underneath the urinal mat  10  can also splash up or flow up through holes  42  to thereby contact the block containing bacterial material in the housing  25 . 
         [0051]    The urinal mat in accordance with the preferred embodiment of the present invention comprises a blend of non-pathogenic microorganisms and free enzymes that produces an enzymatic activity to degrade organic matter, whilst filling the washroom with odour masking fragrances. The blend of microorganisms contains strains producing protease, lipase, amylase, cellulase and uriase. These enzymes attack the compounds present in urine to break them down to a state where they can be easily digested by aerobic bacteria present in the block. The solid-state form of surfactant then acts in combination, flushing away the remnants of the urine and helping to clean the outlet pipes. 
         [0052]    Combining an aerobic bacterial/enzyme blend with the solid-state surfactants and masking fragrances gives rise to a three tier approach to managing washroom odours, most of which are a direct result of urine breakdown by anaerobic bacteria in piping. In standard urinals that use a single fragrant masking agent, urine coats the outlet pipes, which results in the formation of uric acid crystals. These crystals harbour anaerobic bacteria, which are the main culprits in causing unpleasant odours in washrooms. Even when the urinal is not being used, the crystals in the pipes attract moisture and continue to produce many of the odours found offensive, such as ammonia, mercaptans, amines, indioles and skatoles. 
         [0053]    The urinal mat in accordance with preferred embodiments of the present invention includes bacteria producing the enzyme urease which breaks down urea, a product of urine. The urinal mat in accordance with preferred embodiments of the present invention also includes surfactants that are released during urination and flushing. The surfactants assisting cleaning the urinal and the pipes. The surfactants also tend to form a foam as they travel through the pipes with flush water, which results in bacteria that are released from the bacterial block at the same time coating all of the inside of the pipes. Therefore, the bacterial activity takes place across the full periphery of the pipes. The plastic mat and the bacterial block of the urinal mat in accordance with preferred embodiment of the present invention also contain fragrances to mask any undesirable odours. 
         [0054]    The urinal mat may be made from materials that are 100% recyclable. The urinal mat may be packed in a bag with a disposable glove. The urinal mat may be packed in a barrier film which means that the fragrance does not dissipate to any meaningful extent during storage. 
         [0055]    In a preferred embodiment of the present invention, the urinal mat may have a diameter of approximately 180 mm. The central housing that holds the block of bacterial material may have a diameter of about 60 to 65 mm and a height of about 20 to 25 mm. The bristles may have a height of about 5 mm. The feet and legs may have a height of about 2 to 3 mm. It will be appreciated that the mat may have other dimensions. Furthermore, the dimensions of the mat and the shape of the mat may be somewhat driven by the size and shape of the urinal in which the mat is to be used. 
         [0056]    In the present specification and claims (if any), the word ‘comprising’ and its derivatives including ‘comprises’ and ‘comprise’ include each of the stated integers but does not exclude the inclusion of one or more further integers. 
         [0057]    Reference throughout this specification to ‘one embodiment’ or ‘an embodiment’ means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases ‘in one embodiment’ or ‘in an embodiment’ in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations. 
         [0058]    In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.

Summary:
A urinal mat ( 10 ) comprises a mat of plastics material ( 12 ) and a block containing bacterial material, the block being held in a fixed position relative to the mat of plastics material, a water impermeable cover ( 26, 28 ) extending over sides and an upper surface of the block containing bacterial material, the urinal mat further having a lower surface below the block containing bacterial material, the lower surface having one or more apertures ( 42 ) therein.