WO2017013601A1 - Cork soles for footwear and corresponding manufacturing method - Google Patents

Abstract

The present disclosure relates to footwear soles, in particular footwear soles comprising a mixture of 20-40% (p/p) cork having a grain size ranging from 0.5 to 3 mm, and 60-80% (p/p) of an agglomerating polymer material. The present disclosure further relates to the corresponding method for manufacturing these footwear soles.

Description

 DESCRIPTION

 CORK SOLES FOR FOOTWEAR AND THEIR MANUFACTURING PROCESS

 Technical Domain

The present disclosure relates to shoe soles, in particular shoe soles comprising a mixture of cork and polymeric material and its manufacturing process.

State of the art

Documents referring to the use of cork-based products, namely insoles, are known in the art. Cork is used for this purpose as it is a comfortable material for the user's foot and easily molded and adaptable to it, thus causing no discomfort to its user.

However, the use of cork as an integral part of shoe soles is not known. Using cork for this purpose allows the recycling of cork waste, that is, using cork waste from other industries that would otherwise be wasteful.

The reason why cork waste has not been used as shoe soles to date is that cork alone does not have the necessary characteristics, such as abrasion resistance, breakage. , flexion. Accordingly, the present disclosure discloses a sole that uses conjugated cork binding agents.

These facts are described to illustrate the technical problem solved by the embodiments of this document. General description

Cork is a natural, lightweight, waterproof product with thermal properties and abrasion resistant. Cork is still a recyclable, renewable, biodegradable and sustainable product.

The incorporation of cork in products, in particular shoe soles, is an option that favors the preservation of the environment. At the same time, the incorporation of cork in shoe soles also allows the user to absorb the impact of the user, shock absorption, sliding resistance, durability, greater surface friction. In terms of aesthetic effects, it provides a pleasant aesthetic effect.

However, cork itself does not have the attributes and skills to be used as a shoe sole. Thus, it was extremely challenging to obtain a formulation for cork shoe soles and their manufacturing process in which the soles had the desired mechanical properties at break and flexibility.

The present disclosure is therefore based on the disclosure of a strategy for reconciling the use of cork as an integral part of shoe soles together with another material, in particular polymeric material. This mixture, cork and polymeric material, provides a shoe sole with strength, hardness, flexibility and environmentally friendly. To date, this combination and its manufacturing process were nonexistent.

This application describes a shoe sole comprising the following elements:

• 20 - 40% (w / w) of cork with a particle size of 0.5 - 3 mm, preferably with a particle size of 2 - 3 mm; • 60 - 80% (w / w) of a polymeric material and binder selected from a list consisting of: natural rubber, styrene butadiene rubber, nitrile butadiene rubber, ethyl vinyl acetate rubber and mixtures thereof.

The particle size of cork - cork particles - can be measured by many known methods such as sieves and sieves, in particular according to ISO 2030.

The sole described in this disclosure allows the use of cork in large quantities without compromising the mechanical performance of the sole, namely the flexibility at 20 ° C of the sole is 7, this value being the value calculated by ASTM F147 and corresponds to the mandrel number; hardness is between 50-90 Shore A and this value is calculated using a Shore durometer; and the minimum tensile strength is 0.9 to 3.5 MPa, this value being calculated by ASTM F 152.

For best results in one embodiment, the shoe sole may comprise the following elements 40% (w / w) cork and 60% (w / w) of the polymeric material and binder.

For best results in one embodiment, the shoe sole is comprised of cork and the percentage of cork ranges from 20 - 40% (w / w), preferably 22 - 38% (w / w), more than preferably between 25 - 35% (w / w).

For best results in one embodiment, the sole may have a density at a temperature of 20 ° C ranging from 480 - 1250 kg / m ³ , preferably 600 - 740 kg / m ³ .

For best results in one embodiment, the sole may comprise a final thickness between 8 - 12 mm, preferably between 8.5 - 11.5 mm, more preferably between 9.5 - 11 mm, more than preferably 9 - 11 mm.

For best results in one embodiment, the sole may further comprise a film for covering a portion of the sole, in particular the upper part of the sole which is in contact with a user's foot. In one embodiment, the sole may also comprise a set of additives, for example dyes, fragrances, emulsifiers, stabilizers, waterproofers, varnishes, or mixtures thereof.

In one embodiment, the sole described may be a sole for flip flops, flip-flop slippers, espadrilles, sabrines, shoes or boots.

The present application also describes a process of producing the sole described above. This process comprises the following steps: uniformly mixing the 2 - 3 mm particle size cork with a polymeric material and binder selected from the following list: natural rubber, styrene butadiene rubber, nitrile butadiene rubber, ethyl vinyl acetate rubber and mixtures thereof in a ratio of approximately 1: 1; 1: 2; 1: 3, 1: 4; form a block with the obtained mixture; vulcanize the block; demould the block; stabilize the block; cut the block to the desired thickness and shape.

In one embodiment, the process may further comprise a step of placing plastic strips on the sole.

In one embodiment, the method further comprises the predefined image printing step on the sole.

Throughout the description and claims the word "comprises" and variations of the word are not intended to exclude other technical characteristics, additives, components, or steps. Additional objects, advantages and characteristics of disclosure they will become apparent to those skilled in the art upon examination of the description or may be learned by the practice of disclosure. The following examples and figures are provided by way of illustration, and are not intended to be limiting of the present disclosure. Furthermore, the present disclosure encompasses all possible combinations of particular or preferred embodiments described herein.

Brief Description of the Figures

For an easier understanding of the disclosure, attached are figures which represent preferred embodiments of the disclosure which, however, are not intended to limit the subject matter of the present disclosure.

Figure 1: Representation of a preferred embodiment of the present disclosure wherein:

1 represents the shoe sole, in particular, a flip-flop flip-flop sole;

2 - represents a plastic strip.

Detailed Description

The described shoe sole comprises a cork granulate and a polymeric material and binder, in particular rubber which allows to obtain cork soles with improved properties.

Cork is bonded to the polymeric material and binder in a proportion of 20% - 40% (w / w) of cork to 60% - 80% (w / w) of the polymeric material and binder, where the The minimum percentage of cork is 20% (w / w) and the maximum percentage is 40% (w / w), while the minimum percentage of polymeric material and binder is 60% (w / w) and the maximum percentage 80 % (w / w). The polymeric binder material to be used should have good abrasion resistance and flexibility. This material can be selected from the following list: styrene butadiene rubber, natural rubber, nitrile butadiene rubber, ethyl vinyl acetate rubber or mixtures thereof.

[0029] The final products which may have shoe soles in their composition are, for example, flip flops, flip-flop slippers, espadrilles, sabrines, shoes and / or boots.

One embodiment of the present solution is based on the following steps for obtaining a shoe sole, in particular for flip flop slippers:

• joining the cork and the polymeric material and binder, preferably joining and calendering;

• Vulcanize the block at 160 ° C for 8h - 12h;

• demould the block after 12h - 48h;

• stabilize the block produced and allow its solidification;

• laminate the block to the desired thickness to obtain cork boards of the desired final thickness, for example 11 mm;

• cut the cork boards to the desired shape, eg slipper shape, with steel cutting molds by means of a press or cutting machine;

• print of the slipper, achieved through the technique of screen printing;

• fit the plastic strips.

The rubber that can be used can be selected from the following list: styrene butadiene rubber, natural rubber, nitrile butadiene rubber, ethyl vinyl acetate rubber or mixtures thereof. One embodiment of the present disclosure wherein obtaining a shoe sole, whether for a shoe, the block will be laminated to a final thickness of 10 mm while if the shoe is a sabrina, the block will be laminated. laminated so that its final thickness is 8 mm.

Although only particular embodiments of the solution have been represented and described in the present disclosure, one skilled in the art will know how to make modifications and replace some technical characteristics with equivalent ones, depending on the requirements of each situation, without departing from the scope of protection defined by attached claims.

The achievements presented are combinable with each other. The following claims further define preferred embodiments.

Claims

1. a shoe sole comprising the following elements: 20 - 40% (w / w) of cork with a particle size of 0.5 - 3 mm, preferably with a particle size of 2 - 3 mm; 60 - 80% (w / w) of a polymeric material and binder selected from the list consisting of: natural rubber, styrene butadiene rubber, nitrile butadiene rubber, ethyl vinyl acetate rubber and mixtures thereof. Sole according to the preceding claim comprising: 25 - 40% (w / w) of cork; 60 - 75% (w / w) of the polymeric material and binder. Sole according to the preceding claim comprising the following elements 40% (w / w) of cork; 60% (w / w) of the polymeric material and binder. Sole according to the preceding claims wherein cork ranges from 22 - 38% (w / w), more preferably from 25 - 35% (w / w). Sole according to the preceding claims, wherein the density at 20 ° C of the sole ranges from 480 - 1250 kg / m ³ , preferably 600 - 740 kg / m ³ . Sole according to the preceding claims which comprises a final thickness of between 8-12 mm, preferably 8.5-11.5 mm, more preferably 9-11 mm, more preferably 9.5-11 mm. . Sole according to the preceding claims, further comprising a film for covering a part of the sole, in particular the upper part of the sole which is in contact with a user's foot. Sole according to the preceding claims, which further comprises a set of additives selected from the following list: dyes, fragrances, emulsifiers, stabilizers, waterproofing agents, varnishes, or mixtures thereof. Footwear comprising the sole according to any one of the preceding claims, in particular slippers, flip flop slippers, espadrilles, sabrines, shoes or boots. A sole production process as claimed in any one of claims 1-8 which comprises the following steps: uniformly mixing cork particles having a particle size of 0.5 - 3 mm, preferably a particle size of 2 - 3. mm; with a polymeric material and binder selected from the following list: natural rubber, styrene butadiene rubber, nitrile butadiene rubber, ethyl vinyl acetate rubber and mixtures thereof; in a 1: 1 - 1: 4 ratio; preferably 1: 2 - 1: 3; form a block with the obtained mixture; stabilize the block produced; cut the block to the desired thickness and shape. A method according to the preceding claim further comprising a step of placing plastic strips on the sole. The method of claims 10-11 further comprising a step of stamping images on the sole.