INSOLE AND ITS PROCESS OF MANUFACTURING

Abstract

Process of manufacturing an adhesive insole comprising the steps of: i) providing a support layer which delimits a first surface and an opposite second surface, divided through the thickness (S1) of said layer; ii) adjustably coating a part of the first surface with an adhesion layer, in relief and configured to increase the friction coefficient of the latter; iii) applying at least one adhesive layer to a portion of the second surface; iv) providing a protection substrate comprising a substrate support and at least an overlaid detachment promoting layer; v) combining the products of step iii) and of step iv), so that the detachment promoting layer adheres to the adhesive layer; vi) in the thicknesses (S1, S2) of the support layer and of the substrate support forming an insole contour of the insole. The present invention also relates to an insole not exclusively manufactured with such process.

Description

The present invention relates to an adhesive insole in place of a shoe, which may be applied to a sole of the foot of a user and which allows walking freely and without difficulty in environments and on surfaces wherein the use of footwear is usually advisable, such as for example saunas, pools, on rock, beach, asphalt, etc.

On such surfaces, footwear such as slippers or flip-flops are usually used, which offer protection from hazards due to the high temperature of a surface, the risk of slipping or injuries due to irregular surfaces or surfaces wherein bacterial flora have developed which are carriers of infections.

The advantages offered by such footwear are, however, offset by disadvantages such as: difficulty walking on sandy or particularly jagged surfaces, reduced grip or long drying times, with consequent prolonged exposure of the foot to high humidity concentrations, or, in the case of closed shoes, such as aqua shoes, the tendency to collect sandy material inside which is inconvenient to eliminate during use.

As an alternative, the present invention proposes to solve all these drawbacks through the use of an adhesive insole to be applied to the sole of the foot, constructed as specified below.

Such objective is achieved by means of an insole according to claim 11, and through a manufacturing method according to claim 1. The claims dependent thereon show preferred or advantageous embodiments.

The object of the present invention will now be described in detail, with the aid of the accompanying figures, wherein:

FIG. 1 shows a schematization of a method for manufacturing an adhesive insole, object of the present invention, according to a possible embodiment;

FIG. 2 shows a plan view of the support layer, along the arrow II shown in FIG. 1;

FIG. 3 shows a cross-section along the plane III-III shown in FIG. 2;

FIGS. 4 and 5 show the surface features of a support layer in the form of a fabric, according to different embodiments;

FIG. 6 shows a plan view of the support layer, along the arrow VI shown in FIG. 1, after the adjustable coating of the adhesion layer;

FIG. 7 shows a cross-section along the plane VII-VII shown in FIG. 6, where in this figure a walking surface has been schematized which, according to the orientation of such figure, is positioned vertically above the adhesion layer;

FIG. 8 shows a cross-section along the plane VIII-VIII shown in FIG. 1, after applying the adhesive layer;

FIG. 9 shows a cross-section along the plane IX-IX shown in FIG. 1, at the feed of the protection substrate;

FIG. 10 shows a section along the plane X-X shown in FIG. 1, downstream of a joining point U of the products of step iii) and of step iv) of the process illustrated hereinafter;

FIGS. 11, 12 schematize plan views of an adhesive insole according to a first variant of the present invention, respectively from the direction of the first surface and from the direction of the removable substrate support;

FIG. 13 shows a perspective view of an adhesive insole according to a second embodiment of the present invention.

The aforementioned object is achieved by a process for manufacturing an adhesive insole 1—applicable (in particular: adhesively) to a foot sole of a user—comprising steps of:

i) providing (position 100, FIG. 1) a support layer 2 which delimits a first surface 4 (or “lower” surface, according to the orientation of the present insole during its correct use, applied to the foot sole), and an opposite second surface 6 (or, consequently, “upper” surface), separated through the thickness S1 of such layer 2;

ii) adjustably coating (position 102) a part of the first surface 4 with at least one adhesion layer 8, in relief and configured to increase the friction coefficient of the latter surface 4;

iii) applying (position 104) at least one adhesive layer 10 to a predominant or substantially complete portion of the second surface 6;

iv) providing (position 106) a protection substrate 12 comprising a substrate support 14 and at least an overlaid detachment promoting layer 16;

v) combining (position 108) the products of step iii) and of step iv), so that the detachment promoting layer 16 adheres at least to the adhesive layer 10;

vi) at least in the thicknesses S1, S2 of the support layer 2 and of the substrate support 14 forming (position 110) an insole contour 18, 18′ of one or more adhesive insoles 1.

Regarding the terminology used, it should be noted that in the present description the term “adjustably” means an application on a layer with a shape and/or with a specific geometry, leaving other desired areas free.

Taking for example FIG. 6 or FIG. 11, one may observe how the adhesion layer 8 is present in specific areas or islands of the first surface 4 but is otherwise absent from other areas 26 (for example intermediate ones) which remain free of such adhesion layer 8.

According to one embodiment (for example, see FIG. 11), the areas or islands of the adhesion layer 8 could be arranged with greater density in specific areas of the insole 1, for example in areas wherein the latter overlaps the metatarsal bones and the heel of the user's foot (when the insole is worn according to the right size).

According to one embodiment (for example, see FIG. 13), the areas or islands of the adhesion layer 8 could be distributed in a substantially homogeneous manner on the first surface 4.

According to one embodiment, the adjustable application could be obtained with a mask suitable to cover the areas 26 (free areas) so that these are protected from the application of the adhesion layer, such mask delimiting one or more through openings through which the adhesion layer may otherwise penetrate to be applied to the first surface.

It should also be noted that the shape of the islands of the adhesion layer 8 is substantially the same in FIG. 6 and in FIG. 11. Nevertheless, such islands are not in scale in the various representations, since—by way of example—from the width T of the support layer a plurality of insoles may be formed (for example 2-20). Therefore, with respect to the schematization of FIG. 6, the size of the areas/islands wherein the adhesion layer is present will be reduced (as for example shown in FIG. 11).

As regards this adhesion layer, its function is to increase the friction coefficient of the first surface 4, at least in relation to the friction coefficient that the latter has in the absence of the adhesion layer.

According to various embodiments, the shape of the islands of the adhesion layer 8 could be circular/ovoidal, or polygonal (for example triangular, square, rectangular, hexagonal or octagonal).

According to one embodiment, the islands of the adhesion layer 8 are arranged in such a way as to delimit one or more outflow-water passages (for example see the reference number 26), which extend from a central portion of the first surface 4 up to a perimeter or contour of an insole 18 of the support layer 2, so that the water or moisture does not remain trapped beneath the support layer 2 but is free to flow out laterally to said layer 2.

According to one embodiment, the adhesion layer 8 creates an anti-slip layer, i.e. it helps to reduce the slipperiness of the insole 1 (and therefore of the foot to which it is adhered) with respect to the underlying walking surface C.

According to one embodiment, the adhesion layer 8 is flexible, for example to conform to the movement of the user's foot.

According to one embodiment, the support layer 2 could be a non-woven fabric, a film, for example polymeric, a layer of leather or imitation leather or similar.

According to one embodiment, the support layer 2 comprises a weft and warp fabric 20.

According to one embodiment, the weft and warp fabric 20 has fabric weaves different between the first surface 4 and the second surface 6.

Within the present description, the term “fabric weave” means the way of weaving the warp threads with the weft threads. A fabric weave therefore defines the type of fabric obtained from a specific weaving.

According to one embodiment, the different fabric weaves are obtained through a single weaving operation 20, i.e. through the way in which the weft and the warp are intertwined.

According to one embodiment, the different fabric weaves are obtained by joining or coupling a first fabric layer with a first fabric weave with a second fabric layer with a second fabric weave. For example, the first and second fabric layers could be glued or stitched together.

According to one embodiment, the fabric weave of the first surface 4 (and/or of the second surface 6) is a three-dimensional honeycomb weave.

According to one embodiment, the three-dimensional honeycomb weave is arranged on the reverse side of the fabric.

According to one embodiment, the fabric weave of the second surface 6 (and/or of the first surface 4) is a cross twill weave.

According to one embodiment, the cross twill weave is arranged on the obverse side of the fabric.

According to one embodiment, step i) could comprise one or more of the following sub-steps of:

a) coloring or pigmenting one or both surfaces 4, 6 of the support layer 2; and/or
b) impregnating the support layer 2 with a water-repellent, for example to make at least one surface (first 4 or second 6) of grade 5 according to the UNI EN 24920 standard in force at the filing date of this patent application.

According to one embodiment, sub-step a) is carried out by means of an aqueous dispersion of organic pigments, preferably in the presence of anionic and non-ionic surfactants.

According to one embodiment, the support layer 2 i.e. the fabric 20 has a thickness equal to or greater than about 0.5 mm, for example equal to or greater than about 0.6 mm.

According to one embodiment, the support layer 2, i.e. the fabric 20, has a thickness equal to or smaller than about 5 mm, for example equal to or smaller than about 3 mm.

According to one embodiment, the support layer 2, i.e. the fabric 20, has a weight in the range 200-600 g/m2, for example about 230-430 g/m2. By way of example, such weight could be determined according to that which is established by the UNI 5114/82 standard in force on the date of filing this application.

According to one embodiment, the fabric 20 comprises at least one elasticized thread or filament in a weft direction and/or in a warp direction.

According to one embodiment, the weft direction is oriented substantially orthogonally with respect to the longitudinal direction L of the adhesive insole 1.

According to one embodiment, the elasticized filament is present only in the weft direction.

According to one embodiment, the elasticized thread or filament of the fabric has a final count within the range 20-80 Nm, for example between 25-55 Nm.

According to one embodiment, the elasticized thread or filament is present in the fabric in a percentage equal to or less than 15%, for example equal to or less than 10%, with respect to the total threads or filaments.

By way of example, the elasticized thread or filament could comprise or consist of a synthetic polyurethane fiber. For example, fibers that may be used for such purpose are known under the trade names Elastam® or Spandex®.

According to one embodiment, the threads or filaments of the fabric other than elasticized threads or filaments have a final count within the range 0.5-10 Nm, for example in the range of 0.5-5 Nm.

According to one embodiment, the threads or filaments of the fabric other than elasticized threads or filaments could be of a synthetic or natural type.

According to various embodiments, the threads or filaments of the fabric (i.e. of the weft and the warp) could be independently selected from the group consisting of: polyethylene, polyamide, polyester, (para-)aramid, polyethylene (optionally polyethylene with a ultra-high molecular weight) and mixtures thereof.

According to various embodiments, the threads or filaments of the fabric could be independently selected from the group consisting of: cotton, linen, jute, coconut, wool, hemp and mixtures thereof, optionally blended with the synthetic fibers or filaments illustrated above.

According to various embodiments, the fabric could comprise or consist of a single type of synthetic fiber (in particular: non-elasticized) and a single elasticized thread or filament. An advantageous variant could for example provide a fabric comprising or consisting of polyamide and polyurethane synthetic fiber.

According to one embodiment, the adhesion layer 8 overlaps at least in part the three-dimensional honeycomb weave, so that the adhesion layer 8 keeps the first surface 4 at a distance D from the walking surface C, creating an intermediate space 22 between such surfaces 4, C for the outflow of water, rain or moisture.

More precisely, the intermediate space (for example visible in FIG. 7) is always present by virtue of the protruding nature of the adhesion layer 8 with respect to the first surface 4. Nevertheless, when the first surface has a three-dimensional honeycomb shape, such intermediate space 22 is increased, and therefore even more efficient in causing the aforementioned outflow.

According to one embodiment, step i) comprises a step of feeding the support layer 2 along a feed direction A substantially parallel to a direction of elasticity or yielding of such layer 2, or along a feed direction A substantially parallel to a predominant extension direction of the elasticized thread or filament of such fabric 20.

According to one embodiment, step vi) is followed by a step vii) of calibrated shrinkage of the support layer 2 with respect to the protection substrate 12 along the elasticity direction, or of the fabric 20 with respect to the protection substrate 12 along the predominant extension direction.

In this way, between the support layer 2 (or fabric 20) and the protection substrate 12, a free grip area 24 is formed—from which the support layer 2 or the fabric 20 has drawn back—for the separation of the protection substrate 12 from the remaining part of the adhesive insole 1, specifically for an easier separation of the protection substrate 12.

In other words, when step vi) is performed, the support layer 2 and the protection substrate 12 are substantially coincident with each other, as this step could be performed, for example, with a single die-cutting operation. Nevertheless, in the subsequent step vii), the inherent elasticity of the support layer 2 or of the fabric 20 induces a calibrated reduction of at least one dimension (length and/or width) of the support layer 2, so that this layer narrows along such dimension occupying a smaller surface of the protection substrate 12.

For example, the calibrated shrinkage could be regulated by a measure of the tension of the support layer 2 along the direction of elasticity, or of the tension of the fabric 20 along the predominant extension direction.

According to one embodiment, the calibrated shrinkage may be equal to or less than 15% (for example, equal or smaller than 10%, or equal to or smaller than 5%, or equal to or smaller than 2%) with respect to a total longitudinal length of the support layer 2 immediately at the end of step vi), i.e. when the layer 2 and the substrate 12 have the same dimensions.

According to one embodiment, the detachment promoting layer comprises a de-adhesive substance, for example a silicone paint.

According to one embodiment, step ii) comprises sub-steps of:

coating a part of the first surface 4 with at least one layer of a liquid precursor of the adhesion layer 8, such precursor comprising at least one thermosensitive expanding substance;

optionally covering at least part of a first layer of an at least partly solidified liquid precursor, with at least one second layer of liquid precursor;

by heating, expanding the expanding substance of the liquid precursor away from the first surface 4, so as to create the relieved adhesion layer 8.

According to one embodiment, the expandable sub-step comprises at least one step of heating the expanding substance to a temperature above about 100° C. (e.g. below 180° C.), optionally for about 1-10 minutes.

According to one embodiment, the expanding substance comprises or consists of expanding powder.

According to one embodiment, step iii) comprises at least one sub-step of transferring a semi-solid adhesive layer 10 precursor from a flexible support to the second surface 6.

In other words, such variant provides that step iii) comprises a transfer of the adhesive layer 10 from a flexible support to the second surface 6.

According to one embodiment, step iii) comprises at least one sub-step of spreading the adhesive layer 10 on the second surface 6, predominantly (i.e., more than 50% of the area of the surface 6) or completely.

According to one embodiment, the adhesive layer 10 comprises a pressure-sensitive adhesive substance.

According to one embodiment, the adhesive layer 10 comprises an adhesive substance cross-linkable with UV rays, for example with UV-C rays.

According to one embodiment, the adhesive substance 10 comprises an acrylic-based substance.

According to one embodiment, the insole or footbed has the shape and size of a human foot, with a recessed space between the first toe and the second toe of a variable length between 3 and 4.5 cm.

According to one embodiment, such recessed space has a width ranging from 0.4 cm (in the narrowest part) to 1.5 cm (in the widest part).

Moreover, according to one embodiment, in the insole or footbed, a cut (for example of about 1 centimeter) is made between the user's second toe and third toe, specifically to allow free movement which usually occurs between these two toes while walking.

According to one embodiment, the insole or footbed has a thickness of about 1 mm, for example in order to minimize its perception by the foot during use.

According to one embodiment, the insole has a thickness in the range 0.8-2.5 mm, for example about 0.8-1.8 mm.

According to one embodiment, the insole or the footbed is made—for example, predominantly or completely—of cotton and/or nylon.

According to one embodiment, the insole is characterized by an average elasticity of about 40%.

According to one embodiment, the adhesive layer is resistant to water and/or sweat.

According to one embodiment, the adhesive layer is hypoallergenic.

According to one embodiment, the adhesive layer is biocompatible according to the ISO 10993 standard in force on the filing date of this application.

The aforementioned objectives are likewise achieved through an adhesive insole as described hereinafter.

The adhesive insole 1 applicable to a foot sole of a user comprises:

i) a support layer 2 which delimits a first surface 4 and an opposite second surface 6, separated through the thickness of such layer;
ii) an adhesion layer 8, which adjustably coats at least one part of the first surface 4, in relief and configured to increase the friction coefficient of the latter;
iii) at least one adhesive layer 10 applied to a predominant or substantially complete portion of the second surface 6;
iv) a protection substrate 12 comprising a substrate support 14 and at least an overlaid detachment promoting layer 16, combined with the support layer 2 such that the detachment promoting layer 16 adheres at least to the adhesive layer 10;
wherein the thicknesses of the support layer 2 and the substrate support 14 form an insole contour 18, 18′.

As embodiments of such an insole require it to be manufactured by the process illustrated above, even where this is not explicit, such an insole could comprise any feature deducible from the preceding description of the process above.

By way of example, according to different embodiments that may can be implemented individually or in combination with each other:

the support layer 2 comprises a weft and warp fabric 20 having optionally different fabric weaves between the first surface 4 and the second surface 6;

the fabric weave of the first surface 4 is a three-dimensional honeycomb weave, and/or the fabric weave of the second surface 6 is a cross twill weave.

the fabric 20 comprises at least one elasticized thread or filament in a weft direction and/or a warp direction;

the adhesion layer 8 overlaps at least in part the three-dimensional honeycomb weave, so that the adhesion layer 8 keeps the first surface 4 at a distance D from a walking surface C, creating an intermediate space 22 between such surfaces 4, C for the outflow of water, rain or moisture.

between the support layer 2 or fabric 20 and the protection substrate 12, a free grip area 24 is present—from which the support layer 2 or the fabric 20 has drawn back in an elastically calibrated way—for the separation of the protection substrate 12 from the remaining part of the adhesive insole 1;

the relieved adhesion layer 8 comprises at least one layer of a thermally-expanded expanding substance; and/or

the fabric 20 consists of a single type of synthetic fiber (for example polyamide), and of a single elasticized thread or filament (for example polyurethane synthetic fiber).

According to one embodiment, the adhesive insole 1 is characterized in that it is disposable.

According to one embodiment, the adhesive insole 1 is breathable.

Purely by way of example, the manufacturing process of an insole shown in FIG. 1 will now be described.

The support layer 2 is fed along a feed direction A, unwinding it from a first feed reel 50.

During such feeding, the support layer 2 is subjected to the discussed steps of coating (step ii), position 102) and of applying (step iii), position 104) and brought to a joining point or area U with the protection substrate 12.

At the same time, the protection substrate 12 is unwound from a second feed reel 52, and is moved in a second feed direction A′ to the joining point or area U.

Optionally, along the feed path, on a back surface 28 of the protection substrate 12 (opposite to the surface on which the detachment promoting layer 16 is present), graphic characters may be imprinted or printed (position 112).

The products of step iii) and of step iv) are then coupled in the joining point or area U, so that the detachment promoting layer 16 adheres at least to the adhesive layer 10.

In a subsequent step (position 110), the adhesive insoles (step vi)) are formed from the coupled material thus created, for example by one or more die-cutting operations.

According to a preferred variant, the forming of the insoles 1 takes place through a separation or cut passing through the coupled material. In other words, in step vi), the separation/die-cutting takes place at a depth that passes through all the layers (identified by the numbers 8, 2, 10, 16, 14) discussed above.

The insoles 1 thus manufactured are then fed to a packing station 114. The residue scrap 56 from the separation is collected in a take-up reel 54 (if in the form of a continuous scrap) or cut into segments to be discarded.

Given the above, the aims pursued by the invention in question are listed below.

Innovatively, the present insole and the present process allow the drawbacks related to the prior art to be successfully resolved.

More precisely, the present insole makes it possible to dispense with the use of shoes or slippers in circumstances wherein the use of these represents an encumbrance or a nuisance for the user.

Advantageously, the invention allows, in general, for one to walk barefoot freely, taking advantage of the benefits provided by the use of footwear.

Advantageously, the invention allows, in particular, to walk “barefoot” (at least with regards the top of the feet) on slippery surfaces without danger (or at least reducing the possibility) of slipping.

Advantageously, the invention allows walking barefoot (according to the previous connotation) on damp and/or wet surfaces without danger (or at least reducing the possibility) of coming into direct contact with the bacterial and/or fungal flora, very often present in large quantities in such conditions.

Advantageously, the invention allows one to walk barefoot (according to the preceding connotation) on jagged or irregular surfaces, such as asphalt, grass, stony soils, sandy soils and rocks, without danger (or at least reducing the possibility) of wounds to the sole of the foot.

Advantageously, the invention allows one to walk on hot or very hot surfaces due to prolonged exposure to the sun without danger (or at least reducing the possibility) of burning.

Advantageously, the present insole has been designed to be resistant to heat, for example, from the body and/or walking surfaces to which such insole is intended to abut against.

Advantageously, the present insole has been designed to become a sort of second skin for the foot, since the support layer 2 is able to dynamically adapt to the movement of the foot while walking.

Advantageously, the present insole has a variability of measurements mainly dictated by the need to standardize the insole to the size of the user's foot.

Advantageously, the measurements of the present insole have been specifically designed to obtain an insole measurement suitable for a plurality of different user soles (obviously within certain limits). In other words, the inventors of this invention have studied a range of insoles capable of covering a plurality of different anthropomorphic sizes.

Purely by way of example, each measurement of the insole could be suitable to cover two foot sizes, for example according to the Italian standard 35-36, 40-41 or similar.

Advantageously, the structure of the insole illustrated above has been designed for the precise purpose of maximizing the adhesion of the insole applied to the foot for the duration of its use, also eliminating the slightest form of hindrance or limitation to the natural movement of the foot while walking.

Advantageously, the step of coating the first surface precedes the step of applying the adhesive layer, in order to avoid thermodynamic conditions which could alter the features (for example of stability and/or biocompatibility) of the adhesive substance.

Advantageously, and in contrast to the technical bias that a honeycomb weave is more delicate than a cross twill weave, the three-dimensional weave faces the walking surface.

This arrangement is due to a number of reasons:

the three-dimensional structure is better suited to the outflow of water or moisture;

the three-dimensional structure lends itself to joining with the adhesion layer, and possibly to be permeated by the liquid precursor thereof;

the three-dimensionality creates a micro-cushioning effect during walking;

for aesthetic factors, by virtue of the movement that three-dimensionality creates.

Advantageously, the presence of a relatively smooth support layer allows better adhesion to the sole of the foot.

Advantageously, the present insole has been designed with a plurality of open outflow channels so as to minimize the presence of liquid under the user's foot.

To the embodiments of the insole and aforesaid process, a person skilled in the art, in order to meet specific needs, may make variants or substitutions of elements with others that are functionally equivalent.

These variants are also contained within the scope of protection as defined by the following claims.

Furthermore, each variant described as belonging to a possible embodiment may be achieved independently of the other variants described.

Claims

1. Process of manufacturing an adhesive insole applicable to a foot sole of a user comprising steps of:

i) providing a support layer which delimits a first surface and an opposite second surface, divided through the thickness (SI) of said layer;

ii) adjustably coating a part of the first surface with at least one adhesion layer, in relief and configured to increase the friction coefficient of the latter;

iii) applying at least one adhesive layer to a predominant or substantially complete portion of the second surface;

iv) providing a protection substrate comprising a substrate support and at least an overlaid detachment promoting layer;

v) combining the products of step iii) and of step iv), so that the detachment promoting layer adheres at least to the adhesive layer;

vi) at least in the thicknesses (SI, S2) of the support layer and of the substrate support, forming an insole contour of one or more adhesive insoles.

2. Process according to claim 1, wherein the support layer comprises a weft and warp fabric having different fabric weaves between the first surface and the second surface.

3. Process according to claim 1, wherein the fabric weave of the first surface is a three-dimensional honeycomb weave, and wherein the fabric weave of the second surface is a cross twill weave.

4. Process according to claim 1, wherein the fabric comprises at least one elasticized thread or filament in a weft direction and/or in a warp direction, for example only in the weft direction, the weft direction being oriented substantially orthogonal with respect to the longitudinal direction (L) of the adhesive insole.

5. Process according to claim 1, wherein the adhesion layer overlaps at least in part the three-dimensional honeycomb weave, so that the adhesion layer maintains the first surface at a distance (D) from a walking surface (C), creating an intermediate space between said surfaces (4, C) for the outflow of water, rain or humidity.

6. Process according to claim 1, wherein step i) comprises a step of feeding the support layer along a feed direction (A) substantially parallel to an elasticity or a yielding direction of said layer, or along a feed direction substantially parallel to a predominant extension direction of the elasticized thread or filament of said fabric.

7. Process according to claim 1, wherein step vi) is followed by a step vii) of calibrated shrinkage—for example equal to or less than 15% with respect to a longitudinal length of the adhesive insole of the support layer with respect to the protection substrate along the elasticity direction, or of the fabric with respect to the protection substrate along the predominant extension direction, so that between the support layer or fabric and the protection substrate a free grip area is formed—from which the support layer or the fabric is drawn back—for the separation of the protection substrate from the remaining part of the adhesive insole.

8. Process according to claim 1, wherein step ii) comprises the sub-steps of:

coating a part of the first surface with at least one layer of a liquid precursor of the adhesion layer, said precursor comprising at least one thermosensitive expanding substance;

optionally covering at least part of a first layer of an at least partly solidified liquid precursor, with at least one second layer of liquid precursor;

by means of heat, expanding the expanding substance of the liquid precursor away from the first surface, so as to create the relieved adhesion layer.

9. Process according to claim 1, wherein the fabric consists of a single type of synthetic fiber, for example polyamide, and consists of a single elasticized thread or filament, for example polyurethane synthetic fiber.

10. Process according to claim 1, wherein step iii) comprises at least one sub-step of transferring a semi-solid adhesive layer precursor from a flexible support to the second surface.

11. Adhesive insole applicable to a sole of the foot of a user comprising:

i) a support layer which delimits a first surface and an opposite second surface, divided through the thickness of said layer;

ii) an adhesion layer, which adjustably coats at least a part of the first surface, in relief and configured to increase the friction coefficient of the latter;

iii) at least one adhesive layer applied to a predominant or substantially complete portion of the second surface;

iv) a protection substrate comprising a substrate support and at least an overlaid detachment promoting layer, combined with the support layer such that the detachment promoting layer adheres at least to the adhesive layer;

wherein the thicknesses of the support layer and of the substrate support form an insole contour.

12. Adhesive insole according to claim 1, wherein the support layer comprises a weft and warp fabric having different fabric weaves between the first surface and the second surface.

13. Adhesive insole according to claim 1, wherein the fabric weave of the first surface is a three-dimensional honeycomb weave, and wherein the fabric weave of the second surface is a cross twill weave.

14. Adhesive insole according to claim 11, wherein the fabric comprises at least one elasticized thread or filament in a weft direction and/or in a warp direction, for example only in the weft direction, the weft direction being oriented substantially orthogonal with respect to the longitudinal direction (L) of the insole.

15. Adhesive insole according to claim 11, wherein the adhesion layer overlaps at least in part the three-dimensional honeycomb weave, so that the adhesion layer keeps the first surface at a distance (D) from a walking surface (C), creating an intermediate space between said surfaces for the outflow of water, rain or humidity.

16. Adhesive insole according to claim 11, wherein a free grip area is formed between the support layer or fabric and the protection substrate from which the support layer or the fabric is drawn back in an elastically calibrated manner—for the separation of the protection substrate from the remaining part of the adhesive insole.

17. Adhesive insole according to claim 11, wherein the relieved adhesion layer comprises at least one layer of a thermally-expanded expanding substance.

18. Adhesive insole according to claim 11, wherein the fabric consists of a single type of synthetic fiber, for example polyamide, and consists of a single elasticized thread or filament, for example polyurethane synthetic fiber.

19. Adhesive insole according to claim 1, wherein it is single-use.