A LINING INSOLE

Abstract: A lining insole is disclosed which is washable and detachable from footwear. Thus, the insole may be refreshed by removal of sweat and other materials by a washing process without washing or drying the entire footwear with detrimental results. The lining insole comprises a resilient base layer to which is secured an absorbent layer with preferably an abrasive-resistant barrier layer applied on top of the absorbent layer. These layers are secured together by stitching at least around a peripheral border of the insole. The resilient base layer comprises an impregnated non-woven felt including a coarse-weave scrim to facilitate dimensional stability and stitch retention whilst the absorbent layer generally has a middle portion adapted to absorb and retain perspired sweat until the insole is washed. The lining insole may incorporate deodorant or other perfume to further enhance the freshness of the insole.

Description: - - I A LINING INSOLE The present invention relates to a lining insole and more particularly, but not exclusively, to a lining insole for use 5 with casual footwear such as so-called trainers. It will be understood that in recent times casual shoes in the form of so-called trainers have become very popular. These forms of casual shoe were originally designed for Irrelatively short-term use during a sporting event. Essentially, trainers are athletic shoes. However, it is increasingly becoming the trend to wear this type of shoe throughout the day and for several days in succession. 15 An essential feature of comfortable shoes is that they should absorb the wearer's sweat during use and release that sweat when not in use. Unfortunately, athletic shoes incorporate large areas of towelling and other absorbent materials in order to accommodate the high levels of sweat 20generated, i.e. perspiration during sporting activities. Such towelling and absorbent materials are generally not prone to release of sweat and consequently athletic shoes can begin to smell and discolour rapidly. 25 in order to "freshen" their footwear, there is a tendency for owners of athletic-type casual shoes to wash them in their washing machine, or at least tumble-dry after hand washing, the entire shoe in order to remove discolouration, odour and sweat build-up. It will be appreciated that such operations 30 on a shoe structure can be quite detrimental and can lead to splitting of materials and stitching. The above problems have been further exacerbated by the recent trend, particularly in North America, to wear athletic- 35type footwear without wearing a pair of socks. Thus, the sweat and dirt build-up is increased, whilst also the potential for odour generation is enhanced. 2 It will be known that foam inserts for shoes have been known to absorb odour using activated charcoal or simply including perfume for a deodorising effect. However, such inserts are not washable and rapidly degrade, both in terms of 5 efficiency and integrity. It is an objective of the present invention to provide a detachable lining insole for location detachable within casual footwear such that the insole can be washed repeatedly without JCdetrimental effect. In accordance with the present invention there is provided a washable and detachable lining insole for footwear, said insole comprising a resilient base layer and an absorbent J5Layer, said base layer and said absorbent layer being secured together by border stitching arranged about the edge of the insole, said resilient base layer including a coarse-weave scrim to facilitate stitch and dimensional retention, said absorbent layer being a graded density non-woven felt wherein ^Qsurface portions of said absorbent layer may be generally of a hydrophobic nature in comparison with a middle portion. Thus, said middle portion accumulates, in use, any sweat moisture incident upon said absorbent layer. 25 Preferably, the lining insole includes a surface layer of cellular or open-weave fabric to act as an abrasion barrier and secured upon the top of the absorbent layer. Preferably, the resilient layer is an impregnated, non- wovenI ffeelltt,, ssuuiittaabbllyy iimmpprreeggnnaatteeid to provide strength and resilience with an SBR impregnant. Preferably, the coarse-weave scrim is a hessian-type material made of polyurethane or polypropylene strands. 35 Preferably, the absorbent layer is made of polyester and viscose fibres, said layer being in accordance with International Patent Publication No. WO96/07783 filed on 29th 2 August 1995 or EP-0 388 062. The most appropriate combination of fibres in the middle portion said absorbent layer is in the ration of 55-65% polyester fibre : 35-45% viscose fibre. Additionally, the surface portions of said absorbent layer may 5 contain up to 5% by weight heat-activated bi-component fibres in order to enhance both strength and resilience in the absorbent layer. Preferably, the resilient base layer and absorbent layer, IQLn addition to border stitching, are secured together with lines of stitching between said border stitching. Preferably, the base layer is arranged to facilitate temporary location within footwear to prevent slippage. Such J5temporary location can be achieved using a fleece-and-hook type arrangement whereby the footwear includes one component of the attachment means whilst the lining insole includes the other. VELCRO™ is one appropriate attachment arrangement. 20 An embodiment of the present invention will now be described by way of example only. At the core of the present invention there is a combination of a resilient base layer combined by stitching with an appropriate absorbent layer. The base layer is conveniently a non-woven fabric impregnated ■ 2-with an SBR impregnant to provide resilience and having a coarse-weave scrim embedded within it. The coarse-weave scrim is typically of a hessian-type form with polyurethane strands. The coarse-weave scrim is present to enable the non-woven material to readily accept stitching in a resilient manner and to ensure structural integrity. Essentially, the base layer and the absorbent layer are secured at least about their periphery by border stitching. Obviously, in the most convenient embodiment of the present 35invention the lining insole is cut to be consistent with the footwear in which it is to be accommodated. However, part- lining insoles could be provided if required. Typically, the base layer and the absorbent layer will be cut separately and 2 then stitched together as required. The absorbent layer must be able to retain any perspired sweat whilst in use, but then liberate that sweat when washed. Consequently, the absorbent layer comprises surface portions either side of a middle portion. The surface portions are substantially hydrophobic in nature, whilst the middle portion has a hydrophilic nature or is adopted for accommodation of sweat moisture. This structure is achieved most conveniently 2Cby mechanical needle entanglement of three distinct webs, i.e. carded but unconsolidated layers of fibre. The two surface layers are constituted by respective webs of polyester fibre, whilst the middle web comprises a mixture of polyester fibres and viscose fibres to achieve the desired level of hydrophilic Iφerformance. These distinct webs of fibrous material are needled together in a mechanical entanglement procedure well- known to those skilled in the art. Needle entanglement to provide non-woven felts is well 2Qcnown and involves the use of barbed needles arranged upon a needle board which repeatedly compacts the subject web fibrous material. This compaction by the needle board is in order that the fibres become entangled and thus consolidated. Obviously, the degree of entanglement is indicated by weight 2 ηper square metre and the gauge of the material. In the present invention an absorbent layer is made in accordance with that described in International Patent Publication No. WO96/07783 (British United Shoe Machinery . ) . A first example of the absorbent material is carried out using three fibre webs. The surface portions and middle portion are consolidated to provide an absorbent layer with an area weight in the order of 600 g/rn^. Generally, the surface portions will be slightly thicker than the middle portion 35which is the nature of needle entanglement process. Typically, the surface portions will have a weight in the order of 500 g/m^ and are formed from a 5.0 decitex polyester textile fibre supplied by Hoechst. The middle portion has an j area weight in the order of 300 g/m^ and is formed from Courtaulds ML "0" trilobal viscose rayon fibres which are slightly finer than the polyester fibres in the surface portions, having a decitex of 2.6. In tests, it has been 5 found that this first example of an absorbent layer absorbs liquid, i.e. sweat, readily and transmits it into the absorbent middle portion. The surface portions remain relatively dry and the liquid is substantially retained in the middle portion. When the absorbent layer is placed under joLoad, as would arise e.g. under foot pressure, there is a relatively small amount of liquid wetback to the surface portions. Furthermore, wicking of the absorbent middle portion ensures that the absorbed liquid (sweat) is removed from the region at which it is drawn into the middle portion I5and spread throughout that middle portion thereby ensuring that a large quantity of liquid can be absorbed and retained within the middle portion, even if most of it is introduced into the absorbent middle portion at about the same region. 20 The absorbent layer can be washed a number of times when incorporated into a lining insole with a resilient base layer. This washing operation removes most, if not all, of the absorbed liquid and other material, so the insole is re-usable and deodorised. An alternative absorbent layer is described 25± n European Patent No. EP 0 388 062 (graduated density felt). The material comprises layers of variously needled webs such that the outer areas of the layer have greater entanglement and therefore density as compared to more central regions so that they have significant void space to accommodate liquid. 0κ further alternative for the absorbent layer is a multi- layered material as described, having outer hydrophobic fibre felt layers and inner absorbent layers which may include hydrophilic fibres, the whole material being needled to provide a substantially stable structure. 35 These alternate expanded structure felts are formed by in effect entangling fibres to create a web. This entanglement is achieved using needles which penetrate the web on a 2 downward stroke, and are barbed or hooked in some manner in order to grab fibres on a return stroke and so entangle strands of fibre between respective web layers. This needling operation tends to consolidate the web from a voluminous, 5 highly open structure into a condensed felt, although still having voids. Thus, grading of felts is typically done using density figures. It will be appreciated that although selective needling is possible to create structural differences through the felt layer in the present case as l odescribed in the European Patent above, the outer surface portions of the felt are needled to a greater extent than the said middle portion and so structure is provided within the felt having voids to accommodate sweat, whilst having a structural surface which can take a stitch or other bonding Jitechnique. The alternative as described above is to combine or laminate several pre-needle webs of felt having different properties through such needling process or their fibre composition together to create a desired absorption quality. Again, with a laminated approach it is possible to limit 2Cheedling to specific levels within the material and so determine properties. Typically, the absorbent layer may be made of polyester fibres or viscose rayon fibres or other suitable hydrophilic 2-^Dr hydrophobic fibres depending on desired performance. However, as indicated previously, one of the principle advantages of the present absorbent layer is that the absorbent layer has voids in which sweat liquid can be accommodated, whilst the surface portions has sufficient 3Structural integrity to ensure there is no, or only limited, compression or squeezing effect upon the absorption layer when foot pressure is applied. It will be appreciated that typical absorbent media J ^introduce chemical or physical bonding between the absorbed liquid and the absorbent fibres. Thus, it is difficult to remove the absorbed liquid by a washing process. Furthermore, it may be necessary to sanitise the lining insole at elevated 2 temperatures and possibly using chemicals. The choice of fibre, therefore, is highly important in determining acceptability of the absorbent layer. 5 It is the combination of a base resilient layer and an absorbent layer with, preferably, a surface barrier layer that allow the present lining insole to be refreshed through a washing stage. 10 The resilient base layer preferably comprises a single layer of non-woven material made from polyester fibres, having an impregnated total weight of about 420 g/m^ and a gauge of approximately 1.4 mm. This non-woven felt has a polypropylene scrim incorporated in it during the needling stage. This Jpolypropylene scrim provides for good structural integrity and the ability to retain a stitch. The non-woven felt is impregnated with a SBR impregnant. In order to secure the insole within footwear without 20beinq liable to slippage and crumpling, particularly on insertion of a foot into the footwear, it is necessary to provide an attachment arrangement. Conveniently, this arrangement uses a VELCRO™-type fastening system. Typically, the footwear will incorporate the hook element of the VELCRO™ • "arrangement, whilst the non-woven nature of the resilient base layer will provide the fleece upon which the hooks engage. Obviously, provision of such an attachment arrangement within footwear requires, in most instances, adaptation of the footwear. This can be conducted at first manufacture of the J ^footwear, or by incorporation of a rubber permanent insert in the footwear incorporating at least one part of the attachment arrangement. This insert could be positioned throughout the footwear or just one portion, i.e. the heel end, of the footwear. 35 The essential feature of the present invention is that the lining insole can be removed readily from the footwear and thus washed as a separate item. In fact, the lining insole 2 could be washed in the same manner as a pair of socks; thus a wearer may insert a fresh lining insole each day and then remove it at the end of the day for washing. 5 Typically, in order to facilitate good location between the base resilient layer and the absorbent layer it is necessary to provide cross line stitching between the border stitches about the edge of the lining insole. These cross- stitching lines also help to prevent ruching within the l oabsorbent layer which can eventually create an uncomfortable insole for a wearer. In order to enhance abrasion resistance, it is most preferable to include a surface barrier layer applied to the I5top of the absorbent layer in order to limit abrasion of the non-woven material which forms the absorbent layer. This barrier layer may be any cellular or loose-woven material. However, it is preferable that the material is hydrophobic and resistant to staining in order that the lining insole retains 20its appearance. It will be understood by those skilled in the art that the absorbent layer absorbs most of the perspired sweat. However, by its nature the impregnated non-woven base 25 rβ silient layer may also retain and absorb some sweat, thus ensuring that the wearer's foot does not feel clammy and remains dry. Furthermore, the absorbent layer may be arranged such -*°that its middle portion may include a deodorant, a perfume or anti-microbial/anti-bacterial fibres. Thus, the beneficial effects of such additions can be achieved without allergic reactions from a wearer. 35

Claims: , Claims ; 1. A washable and detachable lining insole for footwear, said insole comprising a resilient base layer and an 5 absorbent layer, said base layer and said absorbent layer being secured together by border stitching arranged about the edge of the insole, said resilient base layer including a coarse-weave scrim to facilitate stitch retention and dimensional integrity, said absorbent layer being a graded jødensity non-woven felt whereby surface portions of said absorbent layer are substantially hydrophobic whilst a middle portion is arranged, in use, to accommodate perspired sweat. 2. A lining insole as claimed in Claim 1 wherein the JSabsorbent layer is arranged such that the middle portion includes a proportion by weight of hydrophilic fibres. 3. A lining insole as claimed in Claim 1 wherein the absorbent layer is arranged such that the surface portions 2Clιave a higher density in comparison with the middle portion, said middle portion thus having a more voluminous profile with such voluminous structure more susceptible to accommodation of absorbed sweat. 25 4. A lining insole as claimed in Claim 1, 2 or 3 wherein a surface barrier layer is applied to the absorbent layer to enhance abrasion resistance in use. 5. A lining insole as claimed in any preceding claim ^^Vherein the resilient base layer is an impregnated non-woven felt. 6. A lining insole as claimed in any preceding claim wherein the coarse-weave scrim is of a hessian-type made from 3-polypropylene strands. 7. A lining insole as claimed in any preceding claim wherein the absorbent layer includes polyester fibres and 2 viscose fibres. 8. A lining insole as claimed in Claim 7 wherein the middle portion of the absorbent layer includes between 55% and 565% by weight polyester fibres and between 35% and 45% by weight viscose fibres. 9. A lining insole as claimed in any preceding claim wherein the resilient base layer and the absorbent layer in jffiddition to being secured together by border stitching have stitch lines extending across the lining insole and between the opposed rows of border stitching. 10. A lining insole as claimed in any preceding claim Jtherein the insole includes fastening means to allow the insole to be detachably secured within footwear. 11. A lining insole as claimed in Claim 10 wherein the attachment means is by way of a hook and fleece mechanism such 2 Oas VELCRO™. 12. A lining insole as claimed in any preceding claim wherein the middle portion of the absorbent layer is adapted to accommodate a deodorant and/or perfume and/or anti- 2%icrobial and/or anti-bacterial fibres. 30 35

Inventors: GILLILAND ROBERT, STARK RUSSELL, GILLILAND, ROBERT, STARK, RUSSELL
Applicants: BRITISH UNITED SHOE MACHINERY, GILLILAND ROBERT, STARK RUSSELL, USM ESPANA SA, BRITISH UNITED SHOE MACHINERY LTD., GILLILAND, ROBERT, STARK, RUSSELL, USM ESPANA, S.L.
Application year: 1997
Main classification: A43B13
IPC codes: A43B13, A43B17