NONWOVEN KERATIN-BASED FOOTWEAR PART

Field of the invention

The invention relates to nonwoven footwear parts.

Background of the invention

The leather industry produces large amounts of by-products such as tannery solid waste e.g. hair that is often disposed to landfill, which has been a growing issue due to environmental concerns.

There is further an increased interest towards renewable resources, however, utilization of the relative short hairs, as by-products from the bovine leather industry, is difficult.

Hence it is an object of the invention to provide nonwoven footwear part comprising hair and which addresses the above-mentioned problems.

Summary of the invention

The invention relates to a nonwoven footwear part, the nonwoven footwear part comprises

- keratin-based fiber

- at least one binder and wherein the keratin-based fiber is bovine hair.

The inventive nonwoven footwear part has several advantages over prior art involving an efficient reuse of waste products from leather industry.

The present invention makes it possible to reuse bovine hair by efficiently bonding the hairs to form in nonwoven fabrics in various forms for different footwear parts. The hair can advantageously be reused directly from the waste part of the leather industry and thereby minimize waste and exploiting the climate friendly technology during production of a footwear part. A footwear part should be understood as any part, which could be smaller parts that may be a part of or even integrated in larger part of the footwear or the nonwoven footwear part could itself constitute a larger part of the footwear such as e.g. an inner sock or a footwear upper.

In an embodiment of the invention, the keratin-based fiber is non-hydrolyzed.

In an advantageous embodiment of the invention, the keratin-based fiber is waste from the process of manufacturing leather on the basis of bovine hides.

In an embodiment of the invention, the nonwoven footwear part is manufactured by an air-laid technology.

Air-laid technology may be a web formation process. Airlaying (airforming) may be a method of forming a web by mixing fibres with hair to for a uniform air- fibre mixture that is then deposited on a moving air-permeable belt or wire.

The air-laid technology may vary and may be optimized with various techniques using diverse or non-conventional techniques for different products.

Advantages that can be achieved by using an air-laid technique are the ability to lay down even short fibers to form homogeneous and continuous web.

In an embodiment of the invention, the keratin-based fiber is released from bovine hides through chemical treatment.

In an embodiment of the invention, the keratin-based fiber is released from bovine hides through chemical treatment by means of at least an alkaline and an enzyme.

In an embodiment of the invention, the released keratin-based fiber has been neutralized with an acid subsequent to the release from bovine hide. In an embodiment of the invention, the keratin-based fiber is released from the bovine hair through a combined chemical treatment and a subsequent mechanical treatment.

The hair attached to the hides may initially be treated with chemicals to release the hair from the follicles where after a mechanical treatment e.g. by tumbling results in that the hair are pulled out and detached from the hide.

In an embodiment of the invention, the keratin-based fiber is released from bovine hides through mechanically shaving or pulled out.

In an embodiment of the invention, the keratin-based fiber is released from bovine hides through mechanically shaving or pulled out, and wherein the mechanically shaving or pulling out is subsequently supplemented by chemical treatment for release of follicles of the hide.

Hence, during the hide unhairing process, based on chemical treatment, the hair is dislodged from its follicle, and thereafter mechanically removed with the hair shaft intact. This process is important during hair removal for the leather industry to avoid unwanted remnants og the hair follicle and/or hair causing undesirable spots and miscolors of the leather.

However, the alkaline treatment of the hair can also cause breakdown of the hair and therefore it can be advantageous to add a possible treatment with acid, which would be favorable for preserving hair from degradation due to alkaline environment/high pH. An example of an acid could be formic acid to adjust pH close to pi of hair keratin and prevent easier breakage of hair during further washing.

In an embodiment of the invention, the nonwoven footwear part is molded.

In an embodiment of the invention, the molding is a shape of a foot.

In an embodiment of the invention, the molding is a shape of a footwear upper. The molding process may be a process directly on the nonwoven footwear part e.g. by heat in a mold or similar and thereby forming the nonwoven footwear part into a particular shape.

However, the molding or shaping of the nonwoven footwear part may also be an indirectly process of the nonwoven footwear part, wherein the nonwoven footwear part is formed when adhered or similar to a second material already having a particular shape. Thereby, the shape of the nonwoven footwear part will be the same as the shape of the supporting material.

In an advantageous embodiment of the invention, the nonwoven footwear part is 3- dimensional shaped.

In an embodiment of the invention, the molding comprises temperatures of less than 180 degree Celsius, such as less than 150 degree Celsius, such as less than 130 degree Celsius, such as less than 110 degree Celsius, such as less than 100 degree Celsius.

In an embodiment of the invention, the molding comprises temperatures between 80 - 180 degree Celsius, such as between 100 - 130 degree Celsius.

In an embodiment of the invention, the molding comprises applying a pressure and wherein the pressure is between 80 bar - 160 bar, such as between 110 bar - 130 bar.

In an embodiment of the invention, the molding time is between 30 sec - 180 sec, such as between 60 sec - 120 sec, such as between 70 sec - 110 sec.

In an embodiment of the invention, the nonwoven footwear part comprises at least 5 % animal hair by weight of the nonwoven footwear part, such as 10 % animal hair by weight of the nonwoven footwear part, such as 20 % animal hair by weight of the nonwoven footwear part, such as 30 % animal hair by weight of the nonwoven footwear part, such as 40 % animal hair by weight of the nonwoven footwear part, such as 50 % animal hair by weight of the nonwoven footwear part, such as at least 60 % animal hair by weight of the nonwoven footwear part, such as at least 70 % animal hair by weight of the nonwoven footwear part, such as at least 80 % animal hair by weight of the nonwoven footwear part, such as at least 90 % animal hair by weight of the nonwoven footwear part.

In an embodiment of the invention, the keratin-based material comprises between 5 % - 100 % animal hair by weight of the nonwoven footwear part, such as between 20 % - 80 % animal hair by weight of the nonwoven footwear part, such as between 50 % - 100 % hair by weight of the nonwoven footwear part, such as between 60 % - 90 % hair by weight of the nonwoven footwear part, such as between 70 % - 80 % hair by weight of the nonwoven footwear part.

In an embodiment of the invention, the nonwoven footwear part comprises between 30 % - 80 % animal hair by weight of the nonwoven footwear part, such as between 30 % - 40 % animal hair by weight of the nonwoven footwear part, such as between 40 % - 50 % animal hair by weight of the nonwoven footwear part, such as between 50 % - 60 % animal hair by weight of the nonwoven footwear part, such as between 60 % - 70 % animal hair by weight of the nonwoven footwear part, such as between 70 % - 80 % animal hair by weight of the nonwoven footwear part.

In an embodiment of the invention, the nonwoven footwear part comprises between 30 % - 80 % animal hair by weight of the nonwoven footwear part, such as between 30 % - 40 % animal hair by weight of the nonwoven footwear part, such as between 40 % - 50 % animal hair by weight of the nonwoven footwear part, such as between 50 % - 60 % animal hair by weight of the nonwoven footwear part, such as between 60 % - 70 % animal hair by weight of the nonwoven footwear part, such as between 70 % - 80 % animal hair by weight of the nonwoven footwear part and wherein the nonwoven footwear part is an insole.

In an embodiment of the invention, the nonwoven footwear part comprises at least 5 % keratin by weight of the nonwoven footwear part. In an embodiment of the invention, the nonwoven footwear part comprises fiber from at least one animal.

In an embodiment of the invention, the nonwoven footwear part comprises a synthetic material.

In an embodiment of the invention, the nonwoven footwear part comprises natural- based synthetic fibers.

A natural-based synthetic fiber may be PLA binding fibers.

In an embodiment of the invention, the nonwoven footwear part comprises less than 70 % binder by weight of the nonwoven footwear part, such as less than 60 % binder by weight of the nonwoven footwear part such as less than 55 % binder by weight of the nonwoven footwear part.

In an embodiment of the invention, the nonwoven footwear part comprises less than 50 % binder by weight of the nonwoven footwear part, such as less than 40 % binder by weight of the nonwoven footwear part, such as less than 30 % binder by weight of the nonwoven footwear part, such as less than 20 % binder by weight of the nonwoven footwear part, such as less than 10 % binder by weight of the nonwoven footwear part.

In an embodiment of the invention, the binder is a thermal binder.

In an embodiment of the invention, the binder comprises at least one component.

In an embodiment of the invention, the binder is a binding fiber.

Heat treatment is a method to bond nonwoven fibers in a physical manner. The bonding relies on thermoplastic properties of a binding fiber. Examples of such thermoplastic binding fibers are homopolymer fibers (e.g. PP), copolymer fibers (Co-PA, Co-PES (e.g. Co-PET)), unstretched amorphous PES fibers (e.g. PET fibers), bi-component fibers, e.g. with core/sheath polymer, core/sheath cross-section, PET/PP, PP/PET, PES/Co-PES, PA6/PA6.6, PA6/PE, PA6/PP, PE/PP, PP/PE, PE/PET, PET/PE, PET/PBT, PLA/co-PLA, PLA/PBS, PHA/PLA.

Other types of bico fibers cross-sections may be segmented pie, islands in the sea and side-by-side. Alternating segments may also be used, such as with stripes, citrus and/or tipped trilobal.

Binding or bonding fibers may be bicomponent fibers that are included in the web formation that when heated activate the component of lower melting of the e.g. synthetic fibers to bond the web. The other component of the fiber can be melted at higher temperature.

The heat transfer into the nonwoven fibers to be bonded can be performed according to thermal conduction, convection, or radiation principles.

Powder may also be present and locked into the web structure of fibers.

In an embodiment of the invention, the binder is a latex binder.

Hereby, a liquid binder may be applied and thereafter dried and cured to obtain a dry and/wet strength.

A bonding process may also be a combination of binders. An example hereof could be a bonding process with latex and thermal bonding in combination wherein the inner part of the product is thermal bonded, and the surface comprises a latex binder. Such combinations may also comprise binding powder.

In an embodiment of the invention, binding of the keratin based fibers in the footwear part is at least partly obtained through chemical bonds and/or physical bonds. In an embodiment of the invention, binding of the keratin based fibers in the footwear part is at least partly obtained through hydrogen bonds and/or physical bonds.

Hereby, the bonding may be achieved by a combination of pressure, humidity, time and temperature to create hydrogen bonds.

In an embodiment of the invention, the length of the animal hair is at least 0.5 mm, such as at least 1 mm, such as at least 3 mm, such as at least 5 mm, such as at least 7 mm, such as at least 10 mm.

In an embodiment of the invention, the length of the animal hair is between 0.5 mm - 25 mm, such as between 1 mm - 20 mm, such as between 2 mm - 15 mm, such as between 3 mm - 10 mm, such as between 5 mm - 8 mm.

In an embodiment of the invention, the length of the animal hair is between 1 mm - 5 mm.

In an embodiment of the invention, the length of the animal hair is between 0.5 mm - 5 mm.

In an embodiment of the invention, the length of the animal hair is at least 0.1 mm, such as at least 1 mm, such as at least 3 mm, such as at least 5 mm, such as at least 7 mm, such as at least 10 mm.

In an embodiment of the invention, the length of the animal hair is between 0.1 mm - 25 mm, such as between 1 mm - 20 mm, such as between 2 mm - 15 mm, such as between 3 mm - 10 mm, such as between 5 mm - 8 mm.

In an embodiment of the invention, the length of the animal hair is less than 25 mm, such as less than 20 mm, such as less than 18 cm, such as less than 13 mm, such as less than 10 mm, such as less than 8 mm, such as less than 5 mm, such as less than 3 mm. In an embodiment of the invention, the length of at least 80 % of the animal hair is between 1.8 mm - 12 mm.

In an embodiment of the invention, the length of at least 50 % of the animal hair is between 0.8 mm - 5 mm.

In an embodiment of the invention, the length of at least 50 % of the animal hair is between 0.4 mm - 8 mm.

In an embodiment of the invention, the length of at least 20 % of the animal hair is between 5 mm - 12 mm.

An advantage of a homogeneous distribution of the length of the animal hair is a strong and efficient mechanical binding of the animal hair during the manufacturing of the nonwoven footwear part, e.g. a footwear insole.

An optimal distribution of the length of the animal hair in the nonwoven footwear part may also minimize the concentration of binders, which is preferable to achieve sustainable nonwoven product having low concentrations of synthetic material.

A homogeneous distribution of the length of the animal hair may improve the material uniformity and hence optimal and controllable performance of the end product.

Furthermore, a homogeneous distribution of the length of the animal hair in the nonwoven footwear part may also minimize segregation of fibers.

In an advantageous embodiment of the invention, the animal hair is pre-processed prior to inclusion into the non-woven footwear part.

Pre-processes are highly advantageous in the preparation of the animal hair to the manufacturing of the nonwoven footwear part.

In an embodiment of the invention, the pre-processing process comprises cleaning. The animal hair may be collected as a waste product from e.g. leather manufacturing and most likely comprise impurities and chemicals that, if the hairs are not prepared by different preparing processes would, would cause drawback during manufacturing.

The hair most likely contains impurities such as e.g. dirt and/or fat derived from the hide and a cleaning step may often be one of the initial steps in a preparing proses.

In an embodiment of the invention, the pre-processing comprises filtering.

All steps of the pre-processes will most advantageously be made equipment suitable for large scale processes e.g. in larger drums or tanks. Several of the steps may require filtering for separation of e.g. liquids and hair.

In an embodiment of the invention, the pre-processing process comprises drying.

After a cleaning step, the hair may be further be processed in a drying step in e.g. tumble dryer with increased temperatures of e.g. 60 - 70 degree Celsius. Different types of equipment may be used in this process, however, during big scale processing large drums such as e.g. drum dryers or conveyer dryers can be used and/or warm air heating tunnels.

A drying process of the hair before manufacturing of the nonwoven fabric and an optional molding process is an advantageous step to avoid drawbacks of excess of water.

In an embodiment of the invention, the pre-processing process comprises tumbling.

In an embodiment of the invention, the pre-processing process comprises shredding.

In an embodiment of the invention, the pre-processing process comprises opening of fibers. In an embodiment of the invention, the pre-processing process comprises tunnel drying.

Tunnel drying may comprise warm air.

In an embodiment of the invention, the pre-processing process comprises radiofrequency drying.

A step of shredding/downsizing of washed and dried hairs before starting the nonwoven manufacturing process (or at start of the process) may also be applied.

In an embodiment of the invention, the pre-processing process comprises functionalization.

An example of functionalization could be plasma treatment to generate functional groups on the surface of the fiber e.g. to improve adhesion properties with other components; or surface treatment to impart water-proofing properties etc.

In an embodiment of the invention, the nonwoven footwear part comprises less than 2 % fat by weight of the nonwoven footwear part, such as less than 1 % fat by weight of the nonwoven footwear part, such as less than 0.5 % fat by weight of the nonwoven footwear part, such as less than 0.2 % fat by weight of the nonwoven footwear part, such as less than 0.1 % fat by weight of the nonwoven footwear part, such as less than 0.05 % fat by weight of the nonwoven footwear part.

In an embodiment of the invention, the nonwoven footwear part comprises between 0.01 % - 2 % fat by weight of the nonwoven footwear part, such as between 0.01 % - 1 % fat by weight of the nonwoven footwear part, such as between 0.01 % - 0.5 % fat by weight of the nonwoven footwear part.

In an embodiment of the invention, the nonwoven footwear part comprises between 0.005 % - 1 % fat by weight of the nonwoven footwear part, such as between 0.005 % - 0.5 % fat by weight of the nonwoven footwear part, such as between 0.005 % - 0.25 % fat by weight of the nonwoven footwear part.

In an embodiment of the invention, the keratin-based fiber is released from bovine hides through chemical treatment and wherein the nonwoven footwear part comprises less than 1 % fat by weight of the nonwoven footwear part.

In an embodiment of the invention, the keratin-based fiber is released from bovine hides through chemical treatment and wherein the nonwoven footwear part comprises between 0.01 % - 2 % fat by weight of the nonwoven footwear part, such as between 0.01 % - 1.5 % fat by weight of the nonwoven footwear part.

In an embodiment of the invention, the keratin-based fiber is released from bovine hides through chemical treatment and wherein the nonwoven footwear part comprises between 0.01 % - 1 % fat by weight of the nonwoven footwear part, such as between 0.01 % - 0.5 % fat by weight of the nonwoven footwear part.

In an embodiment of the invention, the keratin-based fiber is released from bovine hides through chemical treatment and wherein the nonwoven footwear part comprises between 0.005 % - 0.5% fat by weight of the nonwoven footwear part, such as between 0.005 % - 0.75 % fat by weight of the nonwoven footwear part.

Hereby, the controlled fat content according to the provisions of the invention facilitates efficient and strong bonding of the non-woven footwear part.

Measures of fat content can be made by using e.g. the SATRA TM346 method.

In an embodiment of the invention, the nonwoven footwear part comprises less than 10 % moisture by weight of the nonwoven footwear part, such as less than 8 % moisture by weight of the nonwoven footwear part, such as less than 5 % moisture by weight of the nonwoven footwear part. In an embodiment of the invention, the nonwoven footwear part comprises less than 0.5 % fat by weight of the nonwoven footwear part and less than 10 % moisture by weight of the nonwoven footwear part.

In an embodiment of the invention, the nonwoven footwear part comprises less than 0.25 % fat by weight of the nonwoven footwear part and less than 10 % moisture by weight of the nonwoven footwear part.

In an embodiment of the invention, the nonwoven footwear part comprises less than 0.5 % fat by weight of the nonwoven footwear part and less than 5 % moisture by weight of the nonwoven footwear part.

In an embodiment of the invention, the nonwoven footwear part comprises less than 0.25 % fat by weight of the nonwoven footwear part and less than 10 % moisture by weight of the nonwoven footwear part.

In an embodiment of the invention, the nonwoven footwear part has a thickness between 0.5 mm - 10 mm, such as between 1 mm - 9 mm, such as between 2 mm - 8 mm, such as between 3 mm - 7 mm, such as between 4 mm - 6 mm.

In an embodiment of the invention, the water vapour permeability is at least 10 mg/cm2/h, such as at least 15 mg/cm2/h, such as at least 20 mg/cm2/h, such as at least 22 mg/cm2/h, such as at least 25 mg/cm2/h.

In an embodiment of the invention, the water vapour permeability is at least 5 mg/cm2/h, such as at least 8 mg/cm2/h, such as at least 10 mg/cm2/h.

In an embodiment of the invention, the water vapour permeability is between 10 mg/cm2/h - 50 mg/cm2/h, such as between 20 mg/cm2/h - 45 mg/cm2/h, such as between 30 mg/cm2/h - 40 mg/cm2/h. In an embodiment of the invention, the water vapour permeability is at least 50 mg/cm2/h, such as at least 75 mg/cm2/h, such as at least 100 mg/cm2/h, such as at least 125 mg/cm2/h, such as at least 200 mg/cm2/h.

In an embodiment of the invention, the water vapour permeability is between 20 mg/cm2/h - 200 mg/cm2/h, such as between 50 mg/cm2/h - 150 mg/cm2/h, such as between 75 mg/cm2/h - 150 mg/cm2/h, such as between 100 mg/cm2/h - 150 mg/cm2/h.

Water vapour permeability can be measured by e.g. using the SATRA TM172 method.

In an embodiment of the invention, the shrinkage % is less than 3 %, such as less than 2.5 %, such as less than 2 %, such as less than 1.5 %, such as less than 1 %, such as less than 0.5 %, such as less than 0.1 %.

Shrinkage should be understood as heat/steam resistance.

In an embodiment of the invention, the thermal resistivity is at least 0.02 m2C7W, such as at least 0.03 m2C/W, such as at least 0.04 m2C/W, such as at least 0.05 m2C/W, such as at least 0.06 m2C/W, such as at least 0.07 m2C/W, such as at least 0.08 m2C/W, such as at least 0.09 m2C/W, such as at least 1.0 m2C/W.

In an embodiment of the invention, the thermal resistivity is between 0.02 m2C7W - 1.0 m2C/W, such as between 0.03 - 0.09, such as between 0.04 m2C/W - 0.8 m2C/W, such as at least 0.05 m2C/W - 0.07 m2C/W.

In an embodiment of the invention, the thermal resistance is at least 0.02 m2C/W, such as at least 0.03 m2C/W, such as at least 0.04 m2C/W, such as at least 0.05 m2C/W, such as at least 0.06 m2C/W, such as at least 0.07 m2C/W, such as at least 0.08 m2C/W, such as at least 0.09 m2C/W, such as at least 1.0 m2C/W. In an embodiment of the invention, the thermal resistance is between 0.02 m2C7W - 1.0 m2C/W, such as between 0.03 - 0.09, such as between 0.04 m2C/W - 0.8 m2C/W, such as at least 0.05 m2C/W - 0.07 m2C/W.

Thermal resistance R is a measurement of the resistance to heat flow and the higher the value, the better insulation properties.

Thermal conductivity can be measured by SATRA TM146.

In an embodiment of the invention, the nonwoven footwear part comprises antimicrobial activity of at least 5 %, such as at least, 10 %, such as at least 20 %, such as at least 30 %, such as at least 40 %, such as at least 50 %.

Determining the antimicrobial activity can be made under dynamic contact conditions and the method ASTM2149-13 can be used, wherein the antimicrobial activity is measured using two species of bacteria.

In an embodiment of the invention, the density is at least 80 g/cm3, such as at least 100 g/cm3, such as at least 200 g/cm3, such as at least 300 g/cm3, such as at least 500 g/cm3, such as at least 700 g/cm3.

In an embodiment of the invention, the density is between 80 g/cm3 - 1000 g/cm3, such as between 100 g/cm3 - 800 g/cm3, such as between 200 g/cm3 - 700 g/cm3, such as between 300 g/cm3 - 600 g/cm3, such as between 400 g/cm3 - 500 g/cm3.

In an advantageous embodiment of the invention, the nonwoven footwear part is adhered to a support structure.

Adherence of the nonwoven footwear part to a support structure may be facilitated by use of an adhesive and/or special nonwoven processing e.g. a multilayering where binding fibers would be concentrated in one or both of nonwoven sheet surfaces. Applying an adhesive may be before or after moulding of a hair-based nonwoven.

In an embodiment of the invention, the support structure comprises polyurethane (PU). In an embodiment of the invention, the support structure comprises leather.

In an embodiment of the invention, the support structure comprises mycelium-based materials.

In an embodiment of the invention, the support structure comprises plant-based materials.

In an embodiment of the invention, the support structure comprises textile.

In an embodiment of the invention, the support structure is a footwear insole.

In an embodiment of the invention, the support structure is a footwear inlay sole.

In an embodiment of the invention, the support structure is a footwear upper.

In an embodiment of the invention, the nonwoven footwear part is a laminate.

In an embodiment of the invention, the laminate comprises at least two materials, wherein at least one material is the nonwoven footwear part.

The nonwoven footwear part may advantageously be adhered to an additional material that may even provide a shape of the nonwoven footwear part.

Advantages of bonding two or more material together may be in applications that require extra filling, insulation, protection etc.

Advantages can be obtained by laminating the nonwoven footwear part and a membrane (e.g. Goretex or Sympatex) to make a breathable and waterproof fabric. Further, if the application of the nonwoven laminate should contain properties with e.g. high tear strength, a laminate with the nonwoven footwear part and a high strength material such as e.g. Dyneema can be made. The adherence of two materials may be of layers having a similar size or area of the nonwoven footwear part or may be of larger or smaller size compared to the nonwoven footwear part.

The adherence of the nonwoven footwear part to an additional material may on one side of the nonwoven footwear part or on both sides and may even be entirely surrounded by the additional material. An advantageously example hereof could be that the nonwoven footwear part in e.g. an upper could provide e.g. leather for a footwear upper, a leather jacket or similar with advantageous properties such as e.g. insulation.

In an advantageous embodiment of the invention, the nonwoven footwear part comprises at least one active substance.

In an embodiment of the invention, the active substance is antimicrobial.

In an embodiment of the invention, the footwear part comprising the antimicrobial substance has a bacterial reduction of at least 95 %, such as at least 97 %.

Determining the antimicrobial activity can be made under dynamic contact conditions and the method ASTM2149-13 can be used, wherein the antimicrobial activity is measured using two species of bacteria.

In this context, an active substance should be understood as a substance that adds a further function to the nonwoven footwear parts. Examples hereof may be antimicrobial substances to minimize the growth of microorganism to avoid microbial decomposition and/or minimizing odour.

Substances may provide the nonwoven footwear part with a certain structure, softness.

Examples of such active substances may be silver, nano-silver, softener, dyes, perfume etc. and may be applied to the nonwoven footwear part by micro-encapsulation technology, enabling active substances to be fixed to the surface of the fiber or fabric. In an embodiment of the invention, the nonwoven footwear part is coated.

In an advantageous embodiment of the invention, the footwear part is a sole.

The footwear sole may be an inlay sole or an insole and the footwear sole may also be an outsole for a footwear. Here the nonwoven footwear part constitutes the total sole or one or more parts of the sole. The nonwoven footwear part may also be in integrated part of the sole. The integration of the nonwoven footwear part could be a part of a direct injection process.

In an advantageous embodiment of the invention, the footwear sole is an insole.

In an embodiment of the invention, the insole comprises a support material.

An insole should be understood as a sole that by strobel stitching or similar is fixed to the upper.

A support material may e.g. be a reinforcing band or like to improve the needle stitching resistance of the nonwoven footwear part as an insole.

In an advantageous embodiment of the invention, the footwear sole is an inlay sole.

In an embodiment of the invention, the footwear part is an inlay sole.

Advantages of using the invention according to embodiments of the invention for an inlay sole may be the manufacturing of sustainable footwear parts in an efficient reuse of waste products e.g. bovine hair.

Using animal hair in inlay soles may contribute to improved thermal insulation of the inlay soles and footwear.

In an embodiment of the invention, the surface water adsorption of the inlay sole is at least 30.0 mg/cm2/15 min. In an embodiment of the invention, the surface water absorption is at least 30.0 mg/cm2/15 min, such as at least 100 mg/cm2/15 min, such as at least 150 mg/cm2/15 min, such as at least 200 mg/cm2/15 min, such as least 300 mg/cm2/15 min, such as at least 400 mg/cm2/15 min.

In an embodiment of the invention, the surface water desorption of the inlay sole is less than 80 %.

In an embodiment of the invention, the surface water absorption is between 30 mg/cm2/15 min - 500 mg/cm2/15 min, such as between 400 mg/cm2/15 min - 500 mg/cm2/15 min, such as between 300 mg/cm2/15 min - 500 mg/cm2/15 min, such as between 425 mg/cm2/15 min - 475 mg/cm2/15 min.

In an embodiment of the invention, the surface desorption is at least 80 %, such as at least 90 %.

Surface water absorption and desporption may be measured using SATRA TM9. Repellency and desorption may be used interchangeably.

Water absorption, adsorption and desorption may be measured by SATRATM9.

In an embodiment of the invention, the footwear part is a lining of a footwear upper. In an embodiment of the invention, the footwear part in a footwear upper.

In an embodiment of the invention, the footwear part is a sock.

In an embodiment of the invention, the footwear part is an insulation layer in a multilayer of an upper.

In an advantageous embodiment of the invention, the nonwoven footwear part comprises at least one type of keratin-based fibers.

In an advantageous embodiment of the invention, the nonwoven footwear part comprises at least one further different type of fibers.

In an embodiment of the invention, at least one further fiber is regenerated. In an embodiment of the invention, at least one further fiber is a regenerated staple fiber.

In an embodiment of the invention, at least one further fiber is a natural fiber.

In an embodiment of the invention, at least 2 % is a natural fiber, such as at least 5 % is a natural fiber, such as alt least 10 % is a natural fiber, such as at least 15 % is a natural fiber, such as between 2 % - 40 % is a natural fiber, such as between 5 % - 30 % is a natural fiber, such as between 15 % - 25 % is a natural fiber.

In an embodiment of the invention, the natural fiber is a mycelium based fiber.

In an embodiment of the invention, at least one further fiber is cellulose-based.

In an embodiment of the invention, at least one fiber is cellulose-based and wherein the length of the cellulose-based fiber is between 0.5 mm - 54 mm, such as between 1 mm - 10 mm, such as between 1 mm - 7 mm, such as between 1 mm - 5 mm, such as between 2 mm - 5 mm, such as between 3 mm - 10 mm, such as between 10 mm - 54 mm, such as between 20 mm - 54 mm, such as between 30 mm - 54 mm, such as between 40 mm - 54 mm.

In an embodiment of the invention, at least one further fiber is collagen-based.

The non-woven footwear part may also be a mix of fibers from different sources and an example hereof could be e.g. a keratin-based fibers mixed with e.g. cellulose fibers or e.g. collagen fibers or even a mix of those before or during the manufacturing of the nonwoven footwear part.

Thus, the nonwoven footwear part may comprise animal hair, binder, cellulose based fibers and/or collagen-based fibers.

The amounts of animal hair, binder and optionally cellulose based fibers and/or collagen-based fibers in the nonwoven footwear may of course vary, depending on the application of the nonwoven footwear. The invention further relates to a method of manufacturing the nonwoven footwear part according to embodiments of the invention.

The invention further relates to a method of shaping the nonwoven footwear part, comprising providing a nonwoven footwear part, providing a mold, applying heat to the nonwoven footwear part, applying pressure to the nonwoven footwear part.

The invention further relates to a method of shaping the nonwoven footwear part, comprising providing a nonwoven footwear part, providing a supportive material, adhering the footwear part and supportive material by adhesive.

The desired 3D shape may thus be obtained by preforming of the 3D shape of the nonwoven footwear part and preforming of 3D shape of the supportive material.

In an advantageous embodiment of the invention the desired 3D shape may be obtained through pre-shaping of the supportive material and thereafter imposing this shape on the non-woven footwear part by adhering this part to the 3D shaped supportive material.

In an advantageous embodiment of the invention both the supportive material and the non-woven footwear are 3D shaped prior to the mutual adhering.

In yet at further embodiment, the 3D shaping is obtained through shaping of both the supportive material and the non-woven footwear part during the mutual adhering.

The mutual adhering may e.g. be obtained or activated through application of heat. The invention further relates to a footwear comprising the nonwoven footwear part according to embodiments of the invention and manufactured by the method according to embodiments of the invention.

The invention further relates to a footwear sole comprising the nonwoven footwear part according to embodiments of the invention and manufactured by the method according to embodiments of the invention.

Hair is a proteinaceous fiber with a strongly hierarchical organization of subunits, from the a-keratin chains, via intermediate filaments to the fiber.

Hair is essentially composed of keratin but also contains water, pigments, trace elements, and lipids.

Hair and keratin-based fibers may be used interchangeably according to embodiments of the invention.

Keratin-based fibers may comprise staple fibers or filaments. The fiber may be a reconstructed fiber and may comprise other material than keratin.

The term “staple fiber” refers to fibers of discrete length and may be of any composition. Staple fiber may e.g. be provided by division of a keratin-based filament into discrete staple fibers of a certain length. The length may vary dependent on the application.

The term “reconstructed” fiber refers to staple fibers produced on the basis of a number of mechanically sub-divided protein fibrils. The reconstructed fiber may be formed from a protein suspension directed through a nozzle onto a surface for drying. The suspension is dried to remove water and solvent from the suspension and thereby the reconstrued fiber is formed e.g. on a belt or a cylinder surface. Such a manufacturing method of reconstructing fibers on the basis of protein fibrils is e.g. illustrated in WO 2018/149950 or WO 2018/149949 for the use in relation to collagen. The same principle may be applied at least partly when reconstructing a fiber at least partly based on fibril of keratin, in particular fibrils of bovine hair.

"Nonwoven" as used herein and as defined generally by European Disposables and Nonwovens Association (EDANA) is an engineered fibrous assembly, primarily planar, which has been given a designed level of structural integrity by physical and/or chemical means, excluding weaving, knitting or paper making.

Nonwovens can be manufactured in two main ways; felted or bonded. The fabrics use fibers rather than yams; these are laid randomly or in a uniform way to make web-like layers. They are held together by either the felting or bonding process.

The production of bonded nonwovens takes place in three stages, although the technology allows an overlapping of some stages, and in some cases all three stages can take place at the same time.

The three stages are web formation, web bonding and finishing treatment.

Web formation can be manufactured by Drylaid (carded), Drylaid (high loft), Airlaid (short fiber), Wetlaid, Spunlaid, Meltblown and/or Submicron spinning.

Drylaid manufacturing may be the mechanical process which starts from bales of fibers. These fibers may be ‘opened’ and blended after which they are conveyed to the card by air transport. They may then be combed into a web by a carding machine, which is a rotating drum or series of drums covered by card wire (thin strips with teeth). The precise configuration of cards will depend on the type of fiber and the basis weight to be produced. The web can be parallel-laid, where most of the fibers are laid in the machine direction, or they can be randomised. Typical parallel-laid carded webs result in good tensile strength, low elongation and low tear strength in the machine direction and the reverse in the cross direction. Machine parameters and fiber mix can be varied to produce a wide range of fabrics with different properties.

Airlaid manufacturing may be the process where relatively short fibers are fed into a forming head by an airstream. The forming head assures a homogeneous mix of all fibers. By air again, a controlled part of the fiber mix leaves the forming head and is deposited on a moving belt, where a randomly oriented web is formed. Wetlaid may be the process similar to paper manufacturing wherein a dilute slurry of water and fibres may be deposited on a moving wire screen, where the water is drained and the fibers form a web. The web may further be dewatered by pressing between rollers and dried. Impregnation with binders is often included in a later stage of the process. The strength of the random oriented web is rather similar in all directions in the plane of the fabric. A wide range of natural, mineral, synthetic and man-made fibers of varying lengths can be used.

Spunmelt is a generic term describing the manufacturing of nonwoven webs directly from thermoplastic polymers. It encompasses 2 processes, spunlaid and meltblown, often run in combination.

Polymer granules are extruded into filaments through so called spinnerets. The continuous filaments are stretched and quenched before being deposited on conveyor belt to form a uniform web. Co-extrusion of two components leads to bico fibers, either adding more properties to the web or allowing air-through bonding.

Web bonding during these manufacturing methods may be thermal (calendaring, air through), mechanical (needle punching, hydro-entanglement, stitch bonding) and/or chemical bonding.

Finishing treatments can be mechanical treatments, surface modification and/or coating. An example of a coating may be a latex layer that may be applied on a surface of the footwear part, e.g. an insole. By applying such latex layer dusting of e.g. small fibers detaching from the nonwoven footwear may be prevented. Felted fabrics are produced by heating and damp conditions that causes the fibers to curl up, and the scales of the fiber surface locks together and prevents the fibers from straightening out again.

“Bovine” as used herein means, with referral to the traditional taxonomic grouping, a group of animals including e.g. cattle, buffalo, ox, yak etc.

Hide should be understood as the natural skin and hair from an animal e.g. a bovine e.g. a cattle such as a cow. Cowhides may be a by-product or waste product from e.g. the meat and/or milk industry and can be processed into leather.

Footwear should be understood as any type of footwear such as e.g. a sneaker, sport’s shoe, formal shoe, boot, lace up shoe, slip ons, loafers or any other type of footwear

The nonwoven footwear part may be any part of the footwear and examples hereof could be soles, inlay soles, insoles, footwear upper, fillers for footwear upper.

The figures

The invention will be explained in further detail below with reference to the figures of which

Fig. la and b illustrates examples of footwear parts comprising keratin-based fibers, Fig. 2 illustrates examples of molding the footwear parts, and where

Fig. 3 illustrates the preparing processes of the bovine hair.

Detailed description

The invention will be described in detail with reference to the following examples. It should be noted that the examples are provided herein only for the purpose of making further illustration of the invention instead of limiting the claim scope of the invention. Certain nonessential modifications and alterations may be made by those skilled in the art according to the above description of the invention. In fig. la examples of footwear parts (FWP) comprising keratin-based fibers.

The footwear part (FWP) according to embodiments of the invention may be in any form or shape depending of the application of the footwear part (FWP).

Examples could be simple squares used for e.g. fillers or insulation in a footwear upper or examples may be in the form of an entire upper where the footwear part (FWP) constitute the entire upper. An example could be a part produced and/or cut into a form that fits the bottom of a footwear such as an inlay sole or an insole. The footwear part (FWP) may also be formed as an outsole that may comprise a laminate or be an integrated part of an e.g. DIP outsole. The footwear part (FWP) may also be in more advanced forms that could be used for a special design or decoration of the footwear for more astatically purposes.

In fig. lb examples of multi-layered footwear parts (MFWP) are illustrated. The footwear part (FWP) may combined with and/or adhered to a supportive material (SUP). The adherence to the supportive material (SUP) could be on one side of the footwear part (FWP) as illustrated in fig. lb or it could also be on both sides of the footwear part (FWP) as illustrated in fig. lb. The supportive material as illustrated in example lb can be but are not necessarily the same material on both sides. One side could e.g. be PU and another side could be e.g. leather. An example could also be that the supportive material has the footwear part (FWP) adhered on both sides as illustrated in fig. lb.

The examples should not only be understood as illustrated in fig. lb where the entire area of the materials is multi-layered. Examples could also that smaller footwear parts (FWP) are surrounded by a supportive material (SUP) as illustrated in fig. lb or the opposite where the supportive material (SUP) is surrounded by the footwear part (FWP) (not shown).

It should be noted that the non-woven footwear part (FWP) is formed on the basis of keratin-based fibers, preferably cut-offs from bovine hair. The keratin-based fibers may be combined with other types of binder material or binder fibers to obtain the desired coherence between the keratin based fibers of the non-woven sheet or structure. These binders are explained in further details elsewhere in the present application.

The nonwoven footwear part may preferably comprise at least 30% by weight of keratin-based fiber and at least 50 % binder, e.g. 70% by weight of binder.

The supportive material (SUP) may be of any material depending on the application of the layer and the footwear part however, examples hereof may be synthetic such as e.g. PU foam or it may be natural material such as e.g. leather or a mix of different materials. The material may be a textile that may be made from natural fibers, synthetic fibers or a mix of natural and synthetic fibers.

Supportive material can also be understood as a reinforcing material for example as a laminate comprising at least two layers of material wherein the adherence of the at least two layers may be adhered by at least a spot of adherence means. Reinforcement or laminates may be mainly in 2-dimensional shapes and a supportive material may mainly be in 3 -dimensional shapes.

With reference to fig. 2, examples of molding the footwear part is illustrated. The nonwoven footwear part may initially have the form as a sheet or a 2-dimensional flat form. From this flat form, a molding process (MP) may form the material into a 3- dimensional form (TDFWP). The molding process can be a mechanical or heating process with or without a pre-cast.

The molding of the material may also be an indirect molding where the nonwoven material is bound to a supportive material with a certain shape and thereby as a result of the binding to a shaped material, the non-woven material acquires a 3 -dimensional form. The molding process may also be of the nonwoven material and a supportive material at the same time. The 3-dimensional form can be any relevant form of the footwear part and could be a single change in the shape or it could be multiple. Examples of shapes could be a shape formed as a foot; a bend on one side or a curve.

With reference to fig. 3, an example of a preparing process is illustrated. The preparing process may start from a raw hide with hair (HIH) e.g. from cattle. The hide unhairing process (HR) by hair recovery or hair-saving technology is based on chemical treatment causing the hair to be dislodged from its follicle, and therefore, be mechanically removed with the hair shaft intact. Once the hair (HA) is removed from the hide (HI) several processes can be used to prepare the hair for the manufacturing of the nonwoven shoe part.

The hair (HA) most likely contains impurities such as e.g. dirt and/or fat derived from the hide and a cleaning step (CS) may often be one of the initial steps in a preparing process. A cleaning step, may include that the hair is submerged in warm or lukewarm water, treated with chemicals such as e.g. detergents and/or acids and then rinsed. A step of neutralization may also be applied. An example of a detergent may be a degreasing agent in a dilution suitable for the purpose.

After a cleaning step (CS), the hair may be further be processed in a drying step (DRY) in e.g. tumble dryer with increased temperatures of e.g. 60 - 70 degree Celsius. Different types of equipment may be used in this process, however, during big scale processing large drums such as e.g. drum dryers or conveyor dryers can be used. Warm air heating tunnels may also be used.

The preparing process may reduce the amount of fat and/or moisture,

The preparing process may reduce the amount of fat from between e.g. an average of 16 % fat to below 1 % fat.

The preparing process may reduce the amount of moisture from between e.g. 70 % moisture to below 10 %. All steps of the pre-processes will most advantageously be made equipment suitable for large scale processes e.g. in larger drums. Several of the steps may require filtering for separation of e.g. liquids and hair. When the hair is removed for a nonwoven process (NWP), the hide (HI) can advantageously be processed into leather.

List

FWP Footwear part MFWP Multi layered footwear part SUP Supportive material MP Molding process TDFWP 3 -dimensional footwear part HI Hide HIH Hide with hair HR Hair removal HA Hair cs Cleaning step

DRY Drying step

NWP Nonwoven process