A sweat-absorbing, disposable hygienic insert having a permeable inner film in contact with the foot, an outer film, and an absorbent layer intermediate the inner and outer films. The inner film is provided with a plurality of openings produced without removal of material. The absorbent layer has a flexible hygienic pad including absorbent material, hygienic additives and treatment additives. The outer and inner films are attached to one another at their edges, and are attached by at least one bond which passes through the hygienic pad, the bond located inside a boundary defined by the attached edges of the outer and inner films.

FIELD OF THE INVENTION 
The present invention concerns a sole-shaped disposable hygienic insert 
with sweat-absorbing pad, of an article of footwear such as mules, 
half-mules or ballerinas or of an article of clothing such as ankle socks 
or socks of this type including a permeable film in contact with the foot, 
an absorbent layer and a film in contact with the shoe. 
BACKGROUND OF THE INVENTION 
Such an absorbent inner sole is already known from the document FR 87 09 
708. 
In addition, various makers offer inner linings or "inner soles" which are 
not well adapted to the problem of heating up of the feet as a result of 
excessive sweating, their aim being above all to obtain a warmer shoe, or 
height compensation between the shoe and the foot. These essentially flat 
inner soles made of natural products such as skins, leather, cork, 
textiles or synthetic products, are made of a single material or of 
combined materials. 
The average life of these types of linings is equivalent to the life of the 
shoe for the most durable ones; comfort and hygiene are reduced even if 
some linings are washable. In addition, the materials used become either 
weak or more and more rigid, depending on their nature. 
The principle drawbacks are as follows: 
premature ageing through chemical burning of the materials constituting the 
shoe, 
rapid degradation of the qualities of comfort of the walking elements such 
as socks, stockings, or tights, due in particular to the accumulation of 
sweat, 
more or less restricting treatments dispensed on broken skin, blisters, and 
fungal infections, 
emanation of an offensive odour relating to sweat. 
OBJECTIVES AND SUMMARY OF THE INVENTION 
The object of the invention is to remedy these drawbacks, and to this end 
concerns an insert of the type defined above, characterized in that: 
the outer sealing film is very fine, made of synthetic material, 
the hygienic pad of natural materials is highly flexible and lightly 
packed, 
hygienic additives and treatment additives are added to the flexible pad, 
the inner film, a few hundredths of a millimeter thick, is pierced, 
the films are glued or welded to one another at their edges. 
The insert makes it possible to eliminate sweat as uniformly as possible by 
drainage associated with frequent replacement (disposable insert), which 
provides a particularly hygienic lining. The shape of this insert 
corresponds principally to the sole of the foot, but it may extend onto 
the sides and the top, in the mule and ballerina versions. In the very 
economical versions, the insert is flat, in the form of a strip with two 
rounded ends. 
The mule and ballerina versions may also be provided with a textile or a 
film covering the rest of the foot, the ankle and the calf, in order to 
provide an ankle sock and a sock, but also a half-mule version constituted 
only by the front of a mule. 
According to other advantageous characteristics: 
the two films are glued or welded by point-like traverses made in the 
hygienic pad. 
the inner film is pierced with "lanced" holes in the shape of 
micro-funnels, or cut by small slits, single or combined into stars, 
produced without removal of material. 
the insert contains products which in the presence of sweat stiffen the 
insert, comprising pellets or reactive surfaces which gradually change 
colour, depending on the concentration of sweat. 
the insert is extended onto the sides and the top of the foot, either by 
the pad or simply by one or both films, shaped and then glued or welded to 
one another completely or at various points, or by separate upper and vamp 
parts also joined by gluing or welding to the base insert, or it is 
provided with a textile or a film covering the rest of the foot, the ankle 
and the calf in order to provide an ankle sock and a sock. 
the pad is based on sphagnum or loofah. 
point-like aeration passages are provided in the sides and on the top of 
the foot. 
pre-glued adhesive areas, protected by paper before being installed, are 
situated on the outer film in order to be applied, without spoiling, to 
the insole and/or to the sides of the shoe, or situated on the inner film 
of a mule or a ballerina, in the direction of the top and of certain 
lateral areas of the bare or sock-covered foot. 
the insert includes a thin film, covering the inner film, for the 
continuous manufacture of an assembly formed of the outer sealing film, 
the hygienic pad, the inner film, itself optionally provided with another 
film, to form a sheet which is cut out to the shape of the insert to be 
manufactured, the cut-out portions being welded at the same time in order 
to provide the disposable insert.

DESCRIPTION OF A PREFERRED EMBODIMENT 
According to FIG. 1, the invention, applied to the production of an inner 
sole, consists of a hygienic insert with a sweat-absorbing pad, composed 
of a very fine sealing outer film 1 (that is to say, arranged underneath) 
made of synthetic material. This film is provided with a hygienic pad 2 of 
absorbent natural material which is highly flexible and lightly packed, 
containing hygienic additives and treatment additives indicated 
diagrammatically by the reference 3. 
The pad 2 is covered with an inner film 4 a few hundredths of a millimeter 
thick. This film is pierced to allow sweat to pass through. This is the 
face which will be next to the foot. In FIG. 1 the inner film 4 (that is 
to say, next to the foot) is lifted up at the front to show the pad 2. 
According to the invention, the films 1 and 4 are glued or welded to one 
another at their edge. They may also be joined by point-like bonds 6 
passing through the pad 2. 
The inner film 4 is provided with lanced holes in the shape of 
micro-funnels; it may also be cut by small slits, single or combined into 
stars; these holes generally being produced without removal of material. 
Thus, according to FIG. 1, the hygienic insert consists of a structure with 
four components. 
In more detail: 
The sealing film 1 is very fine; it is smooth or cellular and preferably 
its surface is not slippery. This film is applied directly to the mounting 
insole of the shoe in the case of an article of footwear, or inside a sock 
in the case of an article of clothing. Its function is to avoid the 
passage of sweat. This very light film is made principally of synthetic 
material; its thickness is between a few hundredths and a few tenths of a 
millimeter. In certain applications it may be stiffened by a heat 
treatment, for example on the edge portions so as to form a border, or the 
underside of the foot at the front of the insert; however, in spite of 
this shaping, it should remain flexible in order to allow it to be packed 
folded or rolled for distribution. 
The function of the highly flexible hygienic pad 2, placed on the sealing 
film, is to absorb sweat. This very light pad is made of a natural 
material such as cellulose, cotton wool, sphagnum, or loofah; it may also 
be of viscose or materials used singly or combined by mixing, carding, 
combing, pressing, weaving, gluing, flocking, napping, stitching, or 
calendering so as to form a pad approximately 1 to 2 mm thick, the shape 
of which corresponds to that of the insert, but slightly reduced. This pad 
may also be in the shape of a simple strip. If need be, the pad is glued 
onto a film serving for manufacture and for installation, as will be seen 
subsequently. 
The pad 2 contains the hygienic additives and treatment additives 3 to 
reduce sweating, combat skin complaints and give out a deodorant. These 
additives are added to the pad by impregnation or spraying before drying 
or in the form of powder. The additives may be combined with products 
which react slowly with sweat and gradually stiffen the pad as they absorb 
the sweat, in order to constitute an indication of wear; the insert should 
be changed when it reaches certain degrees of stiffness. 
The film 4 may be a film of woven or non-woven cellulose fibres of a few 
tenths of a millimeter. The material may also be a mixed material, a 
mixture of natural materials and synthetic materials such as polyester 
fibres. The film or layer is in contact with the sole of the bare or 
sock-covered foot. 
The edge 5 of the assembly thus formed is provided with a weld or gluing 
along a line or a strip. There are also weld points 6, constituting 
point-like bonds, or weld lines 6', for example in a V-shape, at the 
location of the arch of the foot, so as to immobilise the pad. 
This assembly is provided with two pre-glued lateral wings or with an 
attachment means 7 in order to be immobilised inside the shoe. Finally, 
according to FIG. 1, a pellet 8 reacting to sweat is provided in order to 
constitute a detector. 
The example shown in FIG. 1 corresponds to the simplest form of the 
hygienic insert according to the invention, that is to say an inner sole 
to be placed inside an article of footwear. 
FIG. 2 corresponds to an exemplary embodiment of the invention forming a 
mule 9 or a half-mule 10 if it is just the front part. The hygienic insert 
integrated with this mule or half-mule is the same as that described 
above. The insert is additionally covered by a very thin film, perforated, 
slit, or woven in a very tight mesh 11; in this case the hygienic pad 2 is 
in the form of a rectangular piece corresponding to a strip. An elastic 
edging cord 12 is provided and lateral adhesives 13, as well as adhesive 
inner sole elements 14. The adhesive elements 14 are for example arranged 
on a longitudinal and transverse line. 
FIG. 3 shows an alternative form of hygienic insert in the shape of a 
ballerina 15. The insert is covered by a film 11 pierced with lanced holes 
with an elastic edging cord 12 and a textile sheet 15' covering the rest 
of the foot if the ballerina is combined with a sock. The sides are 
provided with aeration passages 17 and with padded areas 18 identical to 
the base hygienic insert. 
FIGS. 4A, 4B, 5A and 5B are sectional views showing more precisely the 
structure of two assemblies serving for the production of the hygienic 
insert according to the invention. 
According to FIGS. 4A and 4B, a sub-assembly is formed of the impermeable 
film 1, the hygienic pad 2 and the layer based on cellulose fibres 4. The 
film 1 has on its lower face a sticking surface 19 connected to the film 
by the bonding or sticking line 14. 
FIG. 4B shows the assembly according to FIG. 4A, welded or glued along the 
edge 5. 
The alternative assembly shown in FIGS. 5A and 5B corresponds to a 
five-layer structure comprising the impermeable film 1, the absorbent pad 
2 and the fibre-based film 4, then a film 11 covering the film 4 and a 
very fine sealing film 20 serving for manufacture. 
This film 20 is necessary during the preliminary manufacturing operations; 
it serves as a support by gluing onto the hygienic pad 2 with or without 
the interposition of the layer of cellulose fibres 4. 
In fact, for the production of the hygienic insert according to the 
invention, a continuous process may be used in order to produce the 
assembly, the structure of which is shown in section in FIG. 5A. Depending 
on the nature of the material of which it consists, the hygienic pad 2 is 
more or less fragile and is not self-supporting. 
Inasfar as the insert is obtained by cutting out, a multi-layer assembly 
like that in FIG. 5A is produced continuously. The product may be rolled 
up for transportation between the factory manufacturing this assembly and 
the cutting and welding factory which produces the actual insert. 
For these different operations, it is indispensable to hold certain 
absorbent materials, not self-supporting, by both faces, hence the need 
for the film 20, which is preferably very fine. 
FIG. 5B shows the product provided with welds 5. 
As already indicated above, the upper or inner film 4 has perforations in 
the form of holes which are lanced without removal of material. As a 
result, these perforations have a micro-funnel shape, the wider opening of 
which is situated next to the sole of the foot; sweat passes easily 
through the film during walking; it is retained by capillary action, first 
in the film, then in the hygienic pad. Moreover, the pumping effect 
exerted on the insert during walking facilitates this transfer movement. 
It has also been indicated that the hygienic pad 2 is placed between the 
lower or outer film 1 and the upper or inner film 4 or between, on the one 
hand, the lower film 1 and, on the other hand, the films 4 and 11 in that 
order. These assemblies may be glued or welded at the edge, but they may 
also have there a light holding gluing between the different layers in 
order to avoid internal slipping, or the formation of clumps, bumps or 
local over-thicknesses. 
In the case of the pad 2 and the cellulose-based film 4, micro-gluing which 
allows the transfer of sweat may be provided. 
The point-like fixing traverses produced in the hygienic pad allow 
complementary gluing or welding between the sealing film 1 and the 
cellulose-based film 4, or the sealing film and the pierced, slit, or 
woven film 11 and the film 4, in order to obtain an absorbent assembly 
offering greater homogeneity. These transverse bonds may be almost 
point-like such as those indicated by the reference 6, or linear as 
indicated by the reference 6'; in this case the impression may even 
represent a logo, a trademark or more generally a distinctive symbol 
making it possible to identify the product. According to other 
advantageous characteristics of the invention, the pad, or even the insert 
in general, may include pellets or reactive surfaces such as the pellet 8, 
which gradually react to the concentration of sweat, for example by 
changing colour. 
The pre-glued adhesive areas such as the areas 14 are protected before the 
installation of the insert by siliconized paper, overlapping from these 
areas onto the sealing film 1, so as to be applied to the mounting insole 
and/or to the sides of the shoe by the wings 7 in order to complete the 
holding of the insert, without spoiling the inside of the shoe, that is to 
say, being able to be removed easily without leaving any trace. 
It is also possible to provide mechanical attachment means, beneath the 
sole of the foot or on the wings for rapid installation of the absorbent 
insert. 
In the case of application to articles of footwear, the sides and the top 
of the foot may have point-like aeration passages such as the passages 17. 
Finally, the opening, in the case of application to articles of footwear 
such as mules or ballerinas, may be edged by an elastic cord.