Field of the invention

[001 ] This invention relates to disposable footwear.

Background to the invention

[002] The invention relates specifically to disposable footwear with antimicrobial and other desirable characteristics.

[003] The term "antimicrobial" refers to agents that kill or inhibit the growth of microorganisms. Antimicrobials are grouped according to the microorganisms primarily acted against. For example, antibacterials are used against bacteria and antifungals are used against fungi. Antibacterial agents are further subdivided into bactericidal agents, which kill bacteria, and bacteriostatic agents, which slow down or stall bacterial growth.

[004] Disposable footwear, in the form of overshoes made of non-woven fabrics, are known and commonly used, for instance, in surgical and clean room facilities.

[005] Antimicrobial fabrics, in which the fabric is impregnated with antimicrobial chemicals, are known and commonly used in antimicrobial socks and base layer garments, such as underwear.

[006] The use of antimicrobial fabrics constitutes one of the basic techniques of combating hospital-acquired infections arising from the transfer of microbial agents. Like hospitals, sports facilities and fitness centres are known mechanisms for the transmission of microbially transmitted diseases and the use of antimicrobial fabrics has been extended to the fabrics used in sportswear.

[007] Whilst most garments with antimicrobial characteristics simply make use of antimicrobial-impregnated fabrics, more complex arrangements are known. For instance, US Patent no. 6,499, 320B1 describes a garment fabricated from a knitted or woven material having at least one first yarn made from a conventional garment material and a second yarn that includes an active antimicrobial agent. The knit pattern is designed to cause the conventional garment material to be predominant on the exterior surface of the garment while the yarns containing the antimicrobial agent are predominant on the interior surface of the garment. It will be appreciated that the resultant garment will be relatively expensive and certainly not intended as a disposable garment.

[008] Such a disposable garment is described in US Patent Application no. 2005/0120,463A1 , which discloses a disposable hygienic sock that has an upper, open mesh layer and a lower solid layer that serves as the sole. The sole is provided with a friction-resistant surface configured to prevent a wearer from slipping on slick or wet surfaces and the upper mesh layer allows water to flow into and out of the sock. The use of a relatively hard sole renders this garment, to some extent, less readily disposable and certainly not readily recyclable.

Summary and embodiments of the invention

[009] According to this invention, a disposable item of footwear comprises a sole made from a relatively hydrophobic fabric and an upper made from a relatively hydrophilic fabric. [0010] The term "relatively" refers to the fabric of the sole being substantially more hydrophobic than the fabric of the upper and the fabric of the upper being substantially more hydrophilic than the fabric of the sole.

[001 1 ] The fabric of either or both the sole and the upper preferably include an antimicrobially effective amount of an antimicrobial agent.

[0012] In one form of the invention, the sole and upper fabric are pre-treated with an antimicrobially effective amount of an antimicrobial agent prior to manufacture of the item of footwear. Alternatively, the sole and upper fabric (the entire item of footwear) could be post-treated with the antimicrobial agent.

[0013] The antimicrobial agent preferably includes an anti-fungal agent and more preferably an agent including an effective quantity of Zinc pyrithione.

[0014] The antimicrobial agent preferably also includes an anti-bacterial agent which, in the preferred form of the invention, includes a source of silver ions.

[0015] The item of footwear is preferably an application-specific item of footwear that is configured for use in a specific application or activity.

[0016] One example of an application-specific item of footwear is one configured to operate in wet, watery conditions, which finds particular application as a showering shoe or sock. In this configuration, the item of footwear is preferably fabricated as a disposable sock or sock-like item of footwear, much like a loose slip-on shoe.

[0017] In such a wet sock configuration, the item of footwear may be treated with an antimicrobial agent that includes a source of silver ions formulated for release in the presence of moisture.

[0018] In this form of the invention, the wet sock could have additional conditioning agents impregnated in the fabric, the conditioning agents being adapted for operation and release from the fabric in wet, watery conditions. [0019] For instance, the item of footwear could have soaps, perfumes and emollients impregnated in the fabric that are intended for release upon contact with water during showering use.

[0020] The emollients could be any suitable preparation adapted to soften the skin, selected from any one or more of a moisturizer, cream, lotion, oil, salve, unguent, balm, technical humectant or the like.

[0021 ] In such a configuration, the soaps, emollients and perfumes are configured for release from the fabric in which it is impregnated when the wearer of the sock is in the shower, thereby cleaning, conditioning and moisturising the feet of the wearer whilst at the same time providing antimicrobial protection against pathogens that may be found on the floor of the shower.

Brief description of the drawings

[0022] The invention will be further described with reference to the accompanying drawings in which:

Figure 1 is a diagrammatic plan view on an exemplary item of footwear according to the invention; and

Figure 2 is a diagrammatic under-plan view on the item of footwear of Figure 1 .

Description of embodiments of the invention

[0023] It is generally recognised that public bathing areas, such as the bathrooms and showers of fitness centres, are prime breeding areas for a number of microbial infections, of which the fungal infection athletes' foot is but one.

[0024] The disposable item of footwear of the invention will be described with reference to a showering sock particularly configured for use in the bathrooms and showers of fitness centres in that the item of footwear is configured as a socklike garment that is easy to put on and remove for use during showering. It will be appreciated that this description is intended to provide no more than a non- limiting example of the invention.

[0025] The item of footwear 10 illustrated in the drawings is intended to provide an easy to use, disposable antimicrobial barrier for use in sports and fitness centres and, of course, a number of other shower facilities.

[0026] The item up footwear 10 illustrated in the drawings is fabricated from two types of relatively inexpensive non-woven fabric.

[0027] The fabric is not limited to non-woven fabric and any suitable fabric can be used, including additive manufactured fabrics - additive manufacturing, the industrial version of so-called 3-D printing might be the most appropriate way to manufacture the fabrics used in the manufacture of the item of footwear 10 and additive manufacturing could in fact be used to manufacture the entire item of footwear in a single manufacturing process.

[0028] The item of footwear 10 includes an upper 12 and a sole 14.

[0029] The upper 12 and sole 14 are shaped generally in the form of a sock or slipper, with the sole 14 being stitched to the upper 12 along a peripheral line of stitching 16. To ensure retention of the item of footwear 10 on the foot of a user, the upper 12 is shaped and pleated towards an ankle opening formed along a topline or collar 18 to which an elastic band 20 is stitched. The elastic band 20 serves to retain the item of footwear snugly on the foot of a wearer.

[0030] On the underside of the item of footwear 10 (Figure 2), the sole 14 is slightly reduced in the instep area of the item of footwear 10 by elasticised lines of stitching 22 that draw and pleat the sole into a narrow waist in that area. This is intended to enhance the snug fit of the item of footwear 10 on the foot of a wearer. [0031 ] The fabric of the upper 12 is preferably a non-woven mesh or gauze fabric, the presently preferred fabric being non-woven polypropylene with a fabric weight of between 10 and 20 gsm, preferably 12 gsm. The upper 12 is intended to allow water into the item of footwear 10 during showering and since polypropylene is naturally hydrophobic, the upper fabric is preferably pretreated to render the fabric hydrophilic.

[0032] In view of the fact that the item of footwear 10 is intended to be worn directly against the skin of the wearer, the hydrophilic pretreatment agent must be of cosmetic and medicinal grade. A suitable hydrophilic agent is polysiloxane, which is chemically and clinically inert.

[0033] Equally important is the so-called "hand" of the fabric, which is the feel of the fabric against skin. In the item of footwear 10, it is important that the treatment agents used in the treatment of the fabric enhance rather than detract from the hand or feel of the fabric and that the agents leave the fabric with a soft, comfortable to wear hand or feel. For this reason, it is most preferred to use a pretreatment agent that, in addition to rendering the fabric hydrophilic, also contains a fabric conditioner.

[0034] A number of such agents are available, but a group of particularly suitable agents are those that include one or more of natural vegetable oils, vegetable waxes and natural animal oils such as lanolin as the fabric conditioner. Lanolin has the added benefit of providing an emollient and skin moisturising action during and after use of the item of footwear 10.

[0035] A particularly suitable hydrophilic pretreatment agent and fabric conditioner is RUCOFIN LAN™, a product of Rudolf GmbH, Geretsried, Germany, which is a cationic preparation of polysiloxane, natural vegetable oils, vegetable waxes and lanolin.

[0036] The fabric of the sole 14 is preferably a non-woven mesh or gauze fabric, the presently preferred fabric being non-woven polypropylene with a fabric weight of between 20 and 40 gsm, preferably 30 gsm. The sole fabric is of a heavier grade than the fabric of the upper 12 and the natural hydrophobic characteristics of the fabric are not suppressed with any pretreatment. The hydrophobic sole fabric prevents the ingress of water from the shower floor during use, thereby reducing waterborne transport of any microbial load from the shower floor into the item of footwear 10.

[0037] Like the fabric of the upper 12, the fabric of the sole 14 is pretreated with a fabric conditioner to improve the fabric hand thereof.

[0038] At least the upper 12 of the item of footwear 10 is pretreated by impregnation with an antimicrobial agent, including one or more of an anti-fungal, antibacterial and a bacteriostatic agent, prior to incorporation into the item of footwear 10, the preferred agent being one that is silver-containing, whether as a silver copolymer or silver nanoparticles.

[0039] An example of such an antimicrobial agent is RUCO-BAC AGL™, a product of Rudolf GmbH, an anionic preparation of inorganic salts and surfactants, typically used as a durable hygienic finish for all fibre types except for wool, especially for textiles worn next to the skin. The silver salts in the product impart bactericidal and fungicidal properties to the fabric. The product has no effect on the hydrophilic properties imparted to the fabric.

[0040] In certain countries, such as the USA where the Environmental Protection Agency (EPA) has ruled against the use of RUCO-BAC AGL™ for intimate- contact textiles, RUCO-BAC EPA™ or RUCO-BAC ZPY™, both products of Rudolf GmbH, might provide suitable alternatives, since both products are registered with the EPA.

[0041 ] These products are weakly anionic preparations of metal salts that are used as an antimicrobial protective finish that is particularly suitable for intimate- contact textiles. The products have fungistatic and bacteriostatic properties, particularly Zinc pyrithione, the antimicrobially active ingredient in RUCO-BAC

^ργΤΜ [0042] In addition to the antimicrobial agent, the fabric treatment agents may include additional treatment agents adapted to provide the fabric or disposable item of footwear 10 with cleansing, antiseptic, deodorising, skin moisturising or other properties.

[0043] In the preferred form of the invention, the fabric of at least the upper 12 is pretreated by impregnation to include an emollient which either forms part of or is separate from the fabric conditioner, as described above.

[0044] If desired, the fabric of at least the upper 12 may be pretreated by impregnation to include soap, shampoo or some other cleansing agent formulated for release during showering use to assist in cleaning the feet of the wearer during use.

[0045] The pretreatment agents may also be formulated to include one or more perfuming agents formulated to provide a fresh smell before, during and after showering use.

[0046] In use, a person will put on a pair of the items of footwear 10 to use as wet socks during showering— the wearer will wear and keep the socks 10 on whilst showering.

[0047] During such showering use, the hydrophobic fabric of the sole 14 provides a physical barrier to microbial infection. In addition, the antimicrobial agent to agents in the fabric of at least the upper 12 will inhibit or kill off any microorganisms that might manage to infiltrate the item of footwear 10 before the organisms can infect the wearer.

[0048] The fabric softening agents in the fabric of the sole 14 and upper 12 provide comfort before and during showering use while the moisturising agents, shampoo and perfuming agents facilitate proper foot hygiene, foot skin treatment and moisturising and the added comfort of a fresh smell before, during and after use. [0049] It is believed that the widespread use of the items of footwear 10 in such sports and fitness centre showers and cloakrooms will have the added benefit of vastly reducing microbial infestation of the showers, thereby contributing to the general hygiene of the centres.

[0050] The item of footwear 10 is described above as a "wet" sock or showering sock. It will be appreciated however, that the item of footwear 10 is preferably configured to be dry before use, with the treatment agents being adapted to be initially dry and to be released and operate in wet or watery conditions.

[0051 ] Any suitable fabric that can be formed into an item of footwear may be employed in the manufacture of the disposable item of footwear 10 of the invention. To render the item of footwear more fully disposable however, the fabric must be inexpensive and capable of responsible disposal in that the material must be readily recyclable. The currently preferred material for this purpose is non-woven polypropylene.

[0052] It will be appreciated that the description of the invention set out above is purely illustrative and that the invention may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention and all such variations are intended to be included within the scope of the invention.