FOOTWEAR AND FOOTWEAR PRODUCTION PROCESS

Abstract

Footwear and footwear production process comprises steps that include the reuse of raw materials previously used in footwear or other sources. Such a process also provides for the reduction of waste and environmental impact as well as the elimination of water consumption. A footwear, also the object of the present invention, comprises renewable origin, natural, recycled and recyclable components, being a sustainable product, ecologically viable and inserted in the context of Circular Bio Economy. The footwear presents quality standards in accordance with standard technical standards of quality, overcoming challenges related to obtaining comfortable and simultaneously sustainable shoes.

Claims

1. A footwear production process which comprises the following: (a) cutting a first fabric, obtaining an inner lining and an insole lining; and cutting a first recycled fabric, obtaining an upper, said upper comprising metal-free eyelets; (b) sewing the inner lining on the inner surfaces of the upper; (c) positioning the insole lining on a white latex midsole, and positioning the white latex midsole on a recycled midsole; (d) simultaneous sewing of the insole lining, white latex midsole and recycled midsole at the base of the upper, obtaining an upper with a base, said base comprising an externally exposed recycled midsole surface; (e) bonding a midsole of natural material on the exposed surface of the recycled midsole; obtaining an insole upper, said insole comprising the insole lining, white latex midsole, recycled midsole and natural material midsole, in that order; said insole comprising the surface of the midsole of natural material exposed externally; (f) positioning the upper with an insole in a format-regulating device; (g) adding glue to the side walls of a recycled sole; (h) bonding the side walls of the recycled sole to the lower sides of the upper with an insole; (i) side seam of the recycled sole in the upper with insole, obtaining semi-finished footwear; (j) drying the semi-finished footwear in times between 1 and 8 min, under temperatures between 20 and 60° C., and cooling the semi-finished footwear to room temperature; and (k) adding a removable insole inside the semi-finished footwear and adding laces to the metal-free eyelets present in the upper half of the semi-finished footwear; and obtaining footwear.

2. The process according to claim 1, wherein the upper comprises an upper made of recycled cotton fabric in quantities between 70 and 30% in weight of the upper and recycled plastic fragments in quantities between 30 and 70% in weight of the upper, said upper additionally comprising a foam-based portion of recycled material and a tongue, said tongue comprising a portion for adding a rubber stamp; the midsole of natural material comprises a midsole of coconut fibers; the recycled midsole comprises a midsole of recycled fabric fibers; the recycled sole comprises a mixed sole comprising virgin rubber in amounts between 60 and 40% in weight of the mixed sole and recycled rubber in amounts between 40 and 60% in weight of the sole; and the removable insole comprises a removable insole comprising an upper layer of cork sewn to a lower layer of natural latex, said removable insole additionally comprising an aesthetic layer adhered to its upper surface.

3. The process according to claim 1, wherein the first recycled fabric, the natural material midsole, recycled midsole, the white latex midsole, recycled sole and the removable insole are components originating from footwear in general or the footwear.

4. The process according to claim 1, wherein the first recycled fabric, the natural material midsole, recycled midsole, the white latex midsole, the recycled sole and the removable insole are components of origin distinct from footwear in general.

5. Footwear that comprises the following components: an insole comprising: an insole of coconut fibers glued to the bottom of an insole of recycled fabric fibers; a white latex midsole sewn over the midsole; and an insole lining sewn over the white latex midsole; an upper comprising the insole sewn on its base, said upper being based on a mixture of recycled cotton fabric with recycled plastic fragments; a mixed sole made of virgin rubber and recycled rubber, said mixed sole being glued and sewn to the upper, said mixed sole covering the insole; a removable insole comprising an upper layer of cork sewn to a lower layer of natural latex; and metal-free eyelets.

6. Footwear according to claim 5, wherein the virgin rubber is present in quantities between 60 and 40% in weight of the mixed sole and the recycled rubber is present in quantities between 40 and 60% in weight of the mixed sole.

7. Footwear according to claim 5, wherein the removable insole is insertable inside the upper.

8. Footwear according to claim 5, wherein the upper comprises recycled cotton fabric in quantities between 70 and 30% in weight of the upper and recycled plastic fragments in quantities between 30 and 70% in weight of the upper.

9. Footwear according to claim 5, wherein the upper additionally comprising a foam-based portion of recycled material and a tongue, said tongue comprising a portion for adding a rubber stamp; and the removable insole additionally comprises an aesthetic layer adhered to its upper surface.

10. Footwear according to claim 5, wherein the recycled plastic fragments consist of recycled plastic fragments from plastic bottles.

11. Footwear according to claim 5, further comprises a shoelace.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The subject matter of this Invention will be totally clear in its technical aspects from the detailed description that will be made based on the figures listed below, in which:

[0017] FIG. 1 shows the footwear;

[0018] FIG. 2 shows the footwear and its components;

[0019] FIG. 3 shows the footwear and its components, additionally comprising an aesthetic layer;

[0020] FIG. 4 illustrates the footwear showing the exposed surface of the midsole of recycled fabric fibers prior to bonding the midsole of coconut fibers;

[0021] FIG. 5 illustrates the footwear showing the exposed surface of the coconut fiber midsole right after its bonding to the recycled fabric fiber midsole;

[0022] FIG. 6 shows a footwear embodiment; and

[0023] FIG. 7 shows an embodiment of a pair of removable soles.

DETAILED DESCRIPTION OF THE INVENTION

[0024] In a first aspect, the present invention refers to a FOOTWEAR (1) PRODUCTION PROCESS comprising the following steps: [0025] (a) cutting a first fabric, obtaining an inner lining and an insole lining (F); and cutting a first recycled fabric, obtaining an upper, said upper comprising metal-free eyelets; [0026] (b) stitching the inner lining on the inner surfaces of the upper; [0027] (c) positioning the insole lining (F) on a white latex midsole (L), and positioning the white latex midsole (L) on a recycled midsole; [0028] (d) simultaneous sewing of the insole lining (F), white latex midsole (L) and recycled midsole at the base of the upper, obtaining a upper with a base, said base comprising an externally exposed recycled midsole surface; [0029] (e) bonding a midsole of natural material on the exposed surface of the recycled midsole; obtaining an insole upper, said insole comprising the insole lining (F), white latex midsole (L), recycled midsole and natural material midsole, in that order; said insole comprising the surface of the midsole of natural material exposed externally; [0030] (f) positioning the upper with an insole in a format-regulating device; [0031] (g) adding glue to the side walls of a recycled sole; [0032] (h) bonding the side walls of the recycled sole to the lower sides of the upper with an insole; [0033] (i) side seam of the recycled sole in the upper with insole, obtaining semi-finished footwear; [0034] (j) drying the semi-finished footwear in times between 1 and 8 min, under temperatures between 20 and 60° C., and cooling the semi-finished footwear to room temperature; and [0035] (k) adding a removable insole inside the semi-finished footwear and adding laces to the metal-free eyelets present in the upper half of the semi-finished footwear; and obtaining the footwear (1).

[0036] For the purposes of the present invention, room temperature is understood to be the temperature between 18 and 25° C.

[0037] In step (a) of the process now described, the first fabric comprises a thin cotton fabric, said cotton being recycled organic cotton, without, however, being limited to said thin cotton fabric. The first recycled fabric, in turn, comprises a mixture of recycled cotton fabric and recycled plastic fragments, without, however, being limited to said recycled cotton fabric and recycled plastic fragments. Consequently and in a non-restrictive embodiment of the present invention, the upper covered in step (a) comprises an upper (14, 14a) made of recycled cotton fabric in amounts between 70 and 30% in weight of the upper (14, 14a) and recycled plastic fragments in quantities between 30 and 70% in weight of the upper (14). Said upper (14, 14a) comprises a foam-based portion (14a) of recycled material and a tongue (17). Said tongue (17), in turn, comprises a portion (17a) for adding a rubber stamp.

[0038] Regarding step (b), the internal linings have as their functional objective the protection of the internal surfaces of the upper and the upper surface of the insole.

[0039] In a non-restrictive embodiment of the present invention, the midsole of natural material comprises a midsole (11) of coconut fibers. The recycled midsole, in turn, comprises a midsole (12) of recycled fabric fibers, also known as Strobel. In this context, the insole is a structure comprising four overlapping layers, the upper layer being the lining of the insole (F), the white latex midsole (L) disposed below the insole lining (F), the recycled midsole disposed below the white latex midsole and the natural material midsole disposed below the recycled midsole. In this sense, the presence of the white latex (L) midsole is important for the physical protection of the layers below (recycled midsole and natural material midsole).

[0040] The insole upper features in its inner part the exposed insole surface, said exposed insole surface being the upper surface of the insole lining (F) (on which the removable insole is inserted). In this way, the insole upper is positioned “upside down” on a flat support of the shape-regulating device, so that the flat support fits into the upper with upside-down insole, allowing the upper surface of the flat support to be completely overlapped by the insole surface of the insole lining (F). With this positioning of the upper with an insole, an operator adjusts its shape by hammering the surface of the midsole of natural material exposed externally (still exposed before bonding the recycled sole) which, in this situation, is facing upwards.

[0041] With respect to the bonding that occurs in steps (e), (g) and (h), the glue is added to the exposed surface of the recycled midsole and on the side walls of the recycled sole. The glue present on the surface of the recycled midsole allows the bonding of the natural material midsole just below. The glue present only on the sides of the recycled sole, without extending to its internal surface that will be in contact with the exposed surface of the natural material midsole, allows the surfaces of the recycled sole and the natural material midsole to remain in contact without the presence of glue. This allows for easy recycling of such materials later. The glue is applied three times on the side walls of the recycled sole, and applied twice on the surface of the recycled midsole.

[0042] Regarding step (j), the covered heating allows the optimization of the adhesion between the recycled sole and the insole upper after the addition of glue.

[0043] Still in relation to step (j), the cooling of the semi-finished footwear occurs in a way that the semi-finished footwear goes through a cooling conveyor. In this cooling, the footwear contracts and the glue is activated. In a non-restrictive embodiment of the present invention, the recycled sole comprises a mixed sole (10) comprising virgin rubber in amounts between 60 and 40% in weight of the mixed sole (10) and recycled rubber in amounts between 40 and 60% in weight of the sole (10).

[0044] In the case of step (k) and in a non-restrictive embodiment of the present invention, the removable insole comprises a removable insole (13) comprising an upper layer of cork sewn to a lower layer of natural latex. In a non-restrictive embodiment of the present invention, the removable insole (13) additionally comprises an aesthetic layer (C) adhered to its upper surface, said aesthetic layer (C) comprising the illustration of a brand or illustrations according to the preference of a technician carrying out the process described herein, object of the present invention.

[0045] In a non-restrictive embodiment of the present invention, the first recycled fabric, the natural material midsole, recycled midsole, the white latex (L) midsole, the recycled sole and the removable insole are components originating from footwear in general, being one of the differentials of the process now described with regard to the reuse of recycled, recyclable and natural components. Alternatively, the first recycled fabric, the natural material midsole, recycled midsole, the white latex (L) midsole, the recycled sole and the removable insole are components from the footwear (1) involved in the process described and described below, being another object of the present invention. The reuse of said components reduces waste resulting from the excessive disposal of footwear by presenting components such as these, or even the components themselves, which may have a different origin than footwear in general. In this sense, in a non-restrictive embodiment of the present invention, the first recycled fabric, the natural material midsole, recycled midsole, the white latex (L) midsole, the recycled sole and the removable insole are components from distinct origin of footwear in general. The reuse of such components also allows a circular economy model, as another differential of the process now described, object of the present invention. In this sense, used shoes can return to the process just described, favoring the production of new shoes by reusing their components.

[0046] Still with respect to the process now described, the object of the present invention, it can be performed without the need for water, avoiding waste and excessive use of an indispensable resource for human survival. This is because in the described process there is no step involving dyeing fabrics, since they already have colors and are separated according to the desired color.

[0047] It is important to note that the following description, related to the footwear (1), another object of the present invention, as well as the description of its components, must also be taken into account for the better understanding described here.

[0048] In a second aspect, the present invention relates to a FOOTWEAR (1) comprising the following components: [0049] an internal lining comprising: an insole (11) of coconut fibers glued below an insole (12) of recycled fabric fibers; a white latex midsole (L) sewn over the midsole (12); and an insole lining (F) sewn over the white latex midsole (L); [0050] an upper (14, 14a) comprising the insole sewn on its base, said upper (14, 14a) being based on a mixture of recycled cotton fabric with recycled plastic fragments; [0051] a mixed sole (10) based on virgin rubber and recycled rubber, said mixed sole (10) being glued and sewn on the upper (14, 14a), said mixed sole (10) covering the insole [0052] a removable insole (13) comprising an upper layer of cork sewn to a lower layer of natural latex; and [0053] metal-free eyelets (15).

[0054] With respect to the midsole (11), comprised in the insole, it is a natural material from coconut fiber residues, thus allowing the use and recycling of natural materials, being another differential of the present invention. The use of midsole (11) based on coconut fibers is a sustainable alternative that provides comfort to the user. Most of the state-of-the-art midsoles are made with polyurethane (PU) or EVA, industrialized products that are harmful to the environment and that compromise the health of consumers. Thus, in addition to providing comfort, the use of coconut fibers is a healthy alternative for the planet and its users.

[0055] With respect to the midsole (12), also included in the insole, this consists of a layer arranged on the midsole (11). The recycled fabric fibers that make up the midsole (12) and the lining of the insole (F) are also a differential of the present invention, since they are recycled materials, generating reuse and, simultaneously, guaranteeing greater comfort and softness when walking, as well as absorbing the impact of the step. The white latex midsole (L), also included in said insole, in turn, allows the physical protection of the layers below, namely the midsole (12) (immediately below the midsole (L)) and the midsole (11) (immediately below the midsole (12)).

[0056] Furthermore, said insole is one of the differentials of the present invention because its structure in four layers, based on said midsole (11), said midsole (12), said midsole (L) and the insole lining (F), absorb the impact of the step more efficiently. The order of these layers, that is, the lower disposition of the midsole (11) of coconut fibers, the immediately superior disposition of the midsole (12) of recycled fabric fibers, the immediately superior disposition of the white latex midsole (L) and the immediately superior arrangement of the insole lining (F), is also a differential of the present invention, since if the midsole (11) of coconut fibers was used on the midsole (12) of recycled fabric fibers, on the midsole of white latex (L) or on the lining of the insole (F), the coconut fibers would break apart more easily with continuous use, causing discomfort during use. The same would occur if the coconut fiber midsole (11) was used instead of the cork layer or the natural latex layer present in the removable insole (13). The arrangement of the coconut fiber midsole (11) below the recycled fabric fiber midsole (12) therefore allows for greater durability of the coconut fibers, extending and maximizing the user's comfort. This durability is also improved due to the presence of the white latex midsole (L) above the midsole (12) and (11), as it guarantees physical protection. Additionally, the order described below maximizes the comfort provided by the footwear (1) to the user, said order being: [0057] coconut fiber midsole (11) below the recycled fabric fiber midsole (12); [0058] white latex midsole (L) over midsole (12) made from recycled fabric fibers [0059] insole lining (F) on the white latex midsole (L); [0060] the natural latex layer (present in the removable insole (13)), above the lining of the insole (F); and [0061] the cork layer (present in the removable insole (13)), above the natural latex layer.

[0062] In the case of the upper (14, 14a), it comprises cotton fabric recycled in quantities between 70 and 30% in weight of the upper (14, 14a) and plastic fragments recycled in quantities between 30 and 70% in weight of the upper (14, 14a). In the state-of-the-art the shoe upper is usually made of materials such as leather, suede, canvas or nubuck. Most of these options are not sustainable and, in this sense, this invention also presents recycled cotton fabric as a differential. In addition, the upper (14, 14a) features a mixture of recycled cotton fabric with recycled plastic fragments, creating a new thread. The presence of plastic fragments in this mixture provides greater mechanical resistance to the upper (14, 14a), being one of the differentials of the present invention compared to the state-of-the-art technologies. Also, the presence of plastic fragments in said mixture allows to remove plastic bottles, such as PET bottles, from the environment, giving them a new purpose and making the product even more sustainable. In addition, the upper (14, 14a), as well as the rest of the footwear (1) components are free of ink, as the colors observed come from scraps of fabrics from the textile industry, which are separated by color. The elimination of the need for dyeing consequently eliminates the need to use water in the production process of sustainable footwear, also object of the present invention, as will be seen below. In one embodiment of the present invention, recycled plastic fragments consist of recycled plastic fragments from plastic bottles, preferably PET bottles. Said upper (14, 14a) further comprises a recycled material foam-based portion (14a) and a tongue (17). Said tongue (17), in turn, comprises a portion (17a) for adding a rubber stamp.

[0063] With respect to the mixed sole (10) present in the footwear (1), object of the present invention, this comprises virgin rubber in quantities between 60 and 40% in weight of the mixed sole (10) and recycled rubber in quantities between 40 and 60% in weight of the mixed sole (10). The presence of recycled rubber in the mixed sole (10) also allows the recycling of rubbers that would be discarded in the environment. State-of-the-art footwear features only non-recycled rubbers on the sole, besides, said rubbers are thermoplastic rubbers. The presence of thermoplastic rubber generates contamination and pollution at various levels, including environmental and health problems for domestic and industrial consumers. In addition to having thermoplastic rubber and derivatives, state-of-the-art technologies also do not comprise recycled rubber proposed in the present invention. This gives footwear (1) a differential in the context of sustainability, preservation of the environment and reuse of raw materials. The upper surface of the mixed sole (10) is immediately in contact with the lower surface of the insole without the presence of glue, which facilitates the future recycling of the mixed sole (10) or the insole. Additionally, when glued and sewn on the upper (14), a mixed sole (10) covers the visible portions of the insole, giving it exclusive aesthetics.

[0064] Regarding the removable insole (13), it is insertable inside the upper (14), being positioned just above the lining of the insole (F), said lining of the insole (F) included in the insole already sewn to the upper (14). The removable insole (13) consists of the main footwear (1) insole, being another differential of the present invention in that it provides comfort, promotes sustainability and consumer health due to the presence of the upper layer of cork and the lower layer of natural latex. In addition, the presence of cork in the said removable insole (13) provides antibacterial, anti-odor and anti-moisture properties, and is also a differential compared to state-of-the-art shoes. In a non-restrictive embodiment of the present invention, the removable insole (13) additionally comprises an aesthetic layer (C) adhered to its upper surface, said aesthetic layer (C) comprising the illustration of a brand or illustrations according to the preference of a technician executing the process described herein, object of the present invention.

[0065] It is important to mention the objective of providing a removable insole (13) of only two layers, instead of a removable insole of more than 3 layers. The fact that the number of layers in removable insoles is minimized, bringing them to the insole structure, allows greater protection against moisture and is not exposed to wear, increasing the durability and quality of the product. In the state-of-the-art shoes, for example, there are removable insoles containing, simultaneously, layers of coconut, fabric, latex and cork (4 layers), constantly exposing these layers to wear and moisture, impairing the durability of the shoes. In the present invention, the removable insole (13) comprises only two layers.

[0066] In a non-restrictive embodiment of the present invention, the footwear (1) additionally comprises a lace (16) made of cotton.

[0067] In a non-restrictive embodiment of the present invention, the footwear (1) comprises an internal lining, with a covering and protection function, which covers and protects the internal upper surfaces (14,14a). The lining of the insole (F), similarly to the inner lining that covers the upper internally (14,14a), also has the function of covering and protecting the insole sewn on the upper (14,14a). The inner lining of the upper and the lining of the insole (F) consist of a thin fabric.

[0068] The presence of metal-free eyelets (15) facilitates the recycling of footwear (1), as it eliminates a step of separating the metal eyelets from the upper. In addition, after the separation of said metal eyelets, they are sent to casting processes for reuse. Although it is an option for reusing the metals that make up the metal eyelets, the smelting processes generate polluting and toxic gases, negatively impacting the environment. Therefore, metal-free eyelets (15) also provide less environmental impact, meeting the purpose of the present invention.

[0069] As described, the footwear (1) is a product in which it is intended to maximize its sustainability features, since it has components of renewable origin that, in addition to being recycled, are also recyclable, and can return numerous times to the production process of footwear, also object of the present invention. This is another differential, as it consists of a Circular Bio Economy model in which the products used by consumers are reused in their original production process. Alternatively, if the consumer only decides to discard the footwear (1), it also features components that are easily recycled and decomposed in the environment, reducing negative environmental impacts.

[0070] It is important to reiterate that in addition to making use of natural, recycled and recyclable components, the footwear (1) also presents comfort to the consumer, an unexpected result, since in the sustainable footwear industry the use of natural and recycled products generally decreases the comfort, motivating the business towards the use of virgin raw materials. In this sense, the present invention presents a product that is both comfortable and comprises renewable origin, natural, recycled and recyclable components. In addition, the inappropriate use of natural and recycled products in sustainable footwear also compromises the quality of the product, generating shoes that have structural characteristics that are completely out of compliance. As will be seen in the examples of implementation, the footwear (1) unexpectedly comprises structural characteristics mainly within the conformities required in technical standards of quality standards, better highlighted below.

[0071] Due to the use of renewable, natural, recycled and recyclable components, the footwear (1) avoids environmental damage to nature and man, supporting conservation and preservation practices. In this sense, the high water consumption, environmental degradation and pollution are one of the main problems solved by the present invention in relation to the closest state-of-the-art technologies.

Examples

[0072] Tables 1 and 2 below show the structural characteristics of the footwear (1), showing unexpected results mostly in accordance with technical standards and quality standards. As it is a footwear (1) comprising renewable origin, natural, recycled and recyclable components, the state-of-the-art does not present solutions for the results shown below, being one of the differentials of the present invention.

[0073] It should be understood that the modalities of the invention described in the examples that follow are intended only to highlight technical features that reflect the invention as a whole, without being limited to the examples herein described.

[0074] For the resistance test on the footwear (1), the following materials were used, referring to a sustainable footwear embodiment (1) best illustrated in FIG. 6: [0075] a white/gray footwear (1), left foot, size 35, best illustrated in FIG. 6; [0076] a sample of textile material for cutting, one in white and one in gray; and [0077] a pair of beige soles, size 35, as shown in FIG. 6.

[0078] The results of the footwear (1) resistance tests are shown in table 1.

TABLE-US-00001 TABLE 1 Results of footwear (1) resistance tests according to standard technical standards of quality. Standard technical standards Unit of Test of quality measurement Result Specification Compliance Density ISO2781 - g/cm.sup.3 1.07; 1.07 x x (pycnometer) Met.B/A1: (average = recycled 2010-2008 1.07) fabric fiber Tear ISO20872 - N/mm 6.1 minimum Not resistance - 2001 8.0 compliant sole Seams ISO17697- N/mm >19    minimum Compliant resistance - met.B-2016 10 cut/cut; sneakers tongue Seams ISO17697- N/mm 3.8 - minimum Not resistance - met.B-2016 thread 10 compliant sole/cut; failure internal flexion Seams ISO17697- N/mm 4.3 - minimum Compliant resistance - met.B-2016 thread 10 sole/cut; failure internal flexion Tear EN N 124 + 66 minimum Compliant resistance - ISO17696 - 40 white textile 2004 material - medium strength (X + Y direction) Tear EN N 32   minimum Not resistance - ISO17696 - 40 compliant gray textile 2004 material - medium strength Benwart ISO17707- Mm 0.1 - Maximum Compliant flexural 2005 without 5.0/ strength - slits without 30,000 slits textile material flexions Abrasion ISO20871- mm.sup.3 199    maximum Compliant resistance - 2001 250 back of footwear area Abrasion EN X break without Not resistance: ISO22774- at 2738 break compliant lace and Met.3-2004 cycles orifice - 10,000 cycles Martindale EN x very at most, Compliant abrasion ISO17704- light moderate resistance: 2004 wear wear dry - 12,800 cycles Outside part EN x very at most, Compliant of upper ISO17704- light moderate Martindale 2004 wear wear abrasion resistance: wet - 6,400 cycles Outside part CTCP1-44- N 232 - minimum Not of upper 2013 tearing; 250 compliant Pulling force cut of the textile strip - heel/heel area Flexural EN x no visible no visible Compliant strength - ISO17694- damage damage Bally 2016 method: dry - 80k cycles (X + Y direction) Upper

[0079] According to table 1, most of the results of footwear (1) resistance are in accordance with the standard technical quality standards of Portugal (referenced in table 1), showing unexpected results that reflect one of the differentials of the present invention and its quality standard in relation to state-of-the-art technologies.

[0080] Resistance tests were also carried out on a type of removable insole (13), being a pair of cork-based and natural latex removable insoles (13), size 23, best illustrated in FIG. 7.

[0081] The results of the resistance tests of said pair of removable insoles (13) are shown in table 2.

TABLE-US-00002 TABLE 2 Results of the resistance tests of the pair of removable insoles (13) according to standard technical standards of quality. Standard technical standards Unit of Test of quality measurement Result Specification Compliance Wear over ISO20870- visual no x x time - 7 2017 analysis change in days/70° C./ appearance 100% high resilience (HR) Wear over ISO20870- visual no x X time - 7 2017 analysis change in days/70° C. appearance Cork/natural CTCP1-56- N/mm 0.19 + 0.11 minimum Not latex 2017 0.5 compliant adhesion strength: initial - inside + outside Cork/natural CTCP1-56- N/mm 0.12 x x latex 2017 adhesion strength: after 7 days, 70° C., 100% high resilience (HR) - outside Cork/natural CTCP1-56- N/mm 0.18 x x latex 2017 adhesion strength: after 7 days, 70° C., 100% high resilience (HR) - inside

[0082] According to table 2, most of the resistance results of the pair of removable insoles (13) are in accordance with the standard technical standards of quality of Portugal (referenced in table 2), also showing unexpected results that reflect one of the differentials of the present invention and its quality standard compared to the state-of-the-art technologies.

[0083] It should be understood that the present description does not limit the application to the details described herein and that the invention is capable of other modalities and being practiced or performed in a variety of ways, within the scope of the claims. Although specific terms have been used, these terms should be interpreted in a generic and descriptive sense, and not with a limiting purpose.