WO2018158351A1 - Insole - Google Patents

Abstract

An insole for shoes, comprising a needled nonwoven that contains absorbent fibres and non-absorbent fibres, the non-absorbent fibres comprising structural fibres and binding fibres and the absorbent fibres having at least one portion consisting of superabsorbent polymers. The superabsorbent polymers are in the form of fibres and/or yarn.

Description

 insole

description

The invention relates to an insole for shoes and their use for moisture regulation in the shoe. Furthermore, a manufacturing method suitable for this purpose is specified. A generic insole is known from DE 30 12 1 14 A1. Therein, the task to be solved to create an insole that is very moisture absorbent and still has a high pressure stability.

The solution to this problem is stated in that the

Base material of the insole is a needle felt, which consists of a

A mixture of 15 to 25% rayon fibers and 75 to 85% polyester fibers. About 20% of the polyester fibers are as shrink fibers the

Base material added. Great emphasis is placed on avoiding the

Use of adhesive material laid. The insole made in this way nevertheless has a high strength and is soft and absorbent.

This prior art insole has no supporting function for the foot. Furthermore, it is susceptible to wrinkling and

Shift in the shoe during the running movement. From DE 195 25858 C1 an insole for shoes is known

consisting of a three-dimensionally shaped laminate of two

binder-free nonwoven fabrics, wherein the foot-side nonwoven fabric is thin and abrasion resistant, and the thicker staple base nonwoven fabric constituting the insole base material having a composition of 50 to 60% by weight of core / shell polyester / copolyester fibers

Melting range of the core component from 255 to 260 ° C and

Sheath component of 1 10 to 140 ° C, 5 to 15 wt .-% polyester hochschrumpffasern and 25 to 40 wt .-% absorbent fibers.

The insole described has a very good supporting function and is very stable during use. The viscose fiber used as the moisture absorbent fiber also has satisfactory functionality, but is limited in its moisture absorption. This may not be sufficient for extreme requirements in terms of moisture absorption, for example in the case of very high moisture content.

To increase the moisture absorption capacity it is known

to introduce superabsorbent particles into the insole. However, this has the disadvantage that these particles are not firmly bound and during use of the sole (as a particle or as a gel) can escape from this.

The object of the present invention was therefore, from the

DE 195 25858C1 known insole of the prior art

to further develop that, while maintaining the high stability in use, the moisture absorption is improved.

This object is achieved by an insole for shoes comprising a needle-punched nonwoven fabric comprising absorbent fibers and non-absorbent fibers, wherein the non-absorbent fibers are framework fibers and binder fibers comprise, wherein the absorbent fibers at least a proportion of

superabsorbent polymers which are in fiber and / or yarn form. Surprisingly, it has been found according to the invention that by the use of superabsorbent polymers in fiber and / or yarn form, im

Following also simplifies only called superabsorbent fibers, an insole can be made, which has a high stability and a high and fast moisture absorption at the same time very fast

Has re-drying. In particular, because of their fibrous structure, the superabsorbent fibers can well adhere to the needled nonwoven fabric structure

be integrated, whereby the penetration of the insole can be prevented (high gel stability even under pressure). Another advantage of the insole according to the invention is their high

Water vapor permeability. Because of her excellent

Absorption performance superabsorbent polymers are used according to the invention. Superabsorbent polymers are plastics that are capable of many times their own weight - up to 1,000 times

Absorb liquids. Chemically, superabsorbent polymers are preferably a copolymer of acrylic acid and sodium acrylate, and the ratio of the two monomers may vary.

In addition, a so-called core crosslinker may be added to the monomer solution. This connects the formed long-chain polymer molecules in places with each other by chemical bridges. These bridges make the polymer water insoluble. When water or aqueous salt solutions penetrate into the polymer particle, it swells up and tightens this network at the molecular level. This product is the base polymer. In particular, according to the invention, the term superabsorber is to be understood as meaning the copolymer of acrylic acid and sodium acrylate and polymers derived therefrom. Superabsorbent polymers are capable of absorbing and temporarily binding large amounts of sweat. The usage of

superabsorbent polymers in fiber form has several advantages over particulate superabsorbent polymers. So they are able to direct liquid flows, which allows a targeted discharge of the liquid to be removed. Another advantage is that due to a "wicking effect" fibers on contact with liquid absorb and bind them much faster than particulate substances.

Superabsorbent fibers are z. B. by the company Technical Absorbents Ltd. offered and sold under the brand name Oasis. Like all superabsorbent polymers, they have a very high absorption capacity for aqueous liquids.

The proportion of superabsorbent fibers in the total weight of the

Needle nonwoven fabric is preferably from 1 wt% to 40 wt%, more preferably 5 wt% to 30 wt%, and more preferably from 5 wt% to 20 wt%.

In a preferred embodiment of the invention, the proportion of absorbent fibers in the needled nonwoven is from 10 to 50% by weight, more preferably from 20 to 50% by weight, and most preferably from 30 to 50% by weight.

Preferably, the proportion of non-absorbent fibers on

Total weight of the needled nonwoven from 10% to 90% by weight, still more preferably from 20% to 60% and more preferably from 30% to 50% by weight.

The proportion of framework fibers in the total weight of the needled nonwoven fabric is preferably from 20% to 80%, more preferably from 25% to 50% and more preferably from 30% to 50% by weight. %.

Absorbent fibers are understood according to the invention as fibers

Liquid, especially water, record. Preferably, the absorbent fibers have a water absorption capacity (demineralized

 Water) at 20 ° C of at least 7% by weight, for example from 8% by weight to

20% by weight, more preferably from 10% by weight to 30% by weight.

 Accordingly, non-absorbent fibers have a

 Water absorption capacity at 20 ° C of less than 7 wt .-%, for example from 3 wt .-% to 4 wt .-%, more preferably from 1 wt .-%, to 2 wt .-%, on.

According to the invention, the absorbent fibers preferably contain, in addition to the superabsorbent fibers, other absorbent fibers, preferably viscose fibers, natural fibers, for example hemp, kenaf, cellulose, lyocell, wool or cotton.

The insole according to the invention has binding fibers. These are fibers which are thermally activatable and preferably have a melting point of at least one fiber component of less than 175 ° C, for example from 90 ° C to 175 ° C. An advantage of the use of binding fibers is that they give the insole a very good thermal deformability.

In a preferred embodiment of the invention, the binder fibers comprise polyester fibers, in particular polyester / copolyester core / sheath fibers. In In a preferred embodiment of the invention, the binder fibers comprise core / sheath type fibers. This is advantageous in a high dimensional stability and rigidity in the dry and wet / wet state. The core preferably comprises polyethylene terephthalate and the sheath preferably

Copolyester. The specified core / sheath fibers are commercially available. The copolyester of the sheath component is usually formed from

Polycondensation products of dicarboxylic acids, such as

Terephthalic acid, isophthalic acid or adipic acid, with diol components, such as, for example, polyethylene glycol, butylene glycol or hexamethylene glycol. In this case, the melting range of the copolyester-shell component is preferably from 1 10 to 140 ° C and the polyethylene terephthalate core component of 255 to 260 ° C.

In a further embodiment, polyolefin fibers are used as binder fibers, in particular polypropylene (PP) and polyethylene (PE).

In a preferred embodiment of the invention, the binder fibers comprise shrunken fibers, preferably shrunken polyester fibers,

in particular, the aforesaid core / sheath fibers in shrunken form and high shrinkage monofilament fibers of amorphous polyester.

In a further preferred embodiment of the invention, the proportion of binder fibers in the needle-punched nonwoven fabric is 20 to 70% by weight, more preferably 20 to 60% by weight and in particular 30 to 50% by weight.

The needled nonwoven further contains framework fibers as non-absorbent fibers. Framework fibers advantageously have a melting peak of more than 180 ° C. Particularly preferred framework fibers are polyester fibers, polyamide fibers, aramid fibers, polyacrylonitrile (PAN fibers), polyethylene naphthalate (PEN fibers), polyphenylene sulfide (PPS fibers). The absorbent and non-absorbent fibers may independently of each other have a length of 2 to 100 mm in the needled nonwoven fabric.

They are preferably used with a length of 30 to 90 mm, particularly preferably 35 to 80 mm, more preferably with a length of 38 to 70 mm and most preferably with a length of 38 to 60 mm.

The absorbent and nonabsorbent fibers may independently have a titer of from 0.9 detx to 500 detx, more preferably they are used at a titer of from 0.9 to 80 dtex, more preferably from 1.5 to 70 mm, more particularly preferably with a titer of 1.7 to 1 dtex.

The needle punched nonwoven preferably has a basis weight of 150 to 1200 g / m ² , more preferably 250 to 1200 g / m ² , especially 400 to 1200 g / m ² , measured according to DIN 9073-1. The thickness of the needle-punched nonwoven fabric is preferably 1.5 to 10 mm, more preferably 2.5 to 9 mm, in particular 2.5 to 6 mm, in each case measured according to DIN 9073-2.

Preferably, the needle-punched nonwoven fabric has no binder, in particular no acrylate, latex, polyurethane. However, small amounts of binder, i. less than 8% by weight, based on the total weight of the needled nonwoven fabric. Advantageous of this is a better one

Fluid removal.

The term needled nonwoven is to be understood in the conventional sense.

In particular, a needle-punched nonwoven fabric is a needle-punched non-woven fabric, which mechanically means Needling was solidified. The puncture density is preferably 200 to 350 punctures per cm ² , more preferably 250 to 300 punctures per cm ² .

In one embodiment of the invention, the needled nonwoven is bactericidal and / or fungicidal equipped by an impregnation at least on the side later facing the foot ß.

The later facing the foot side of the insole has a cover layer in a preferred embodiment. This one can

Nonwoven fabric, for example, a coagulated microfiber nonwoven fabric, a thermally bonded nonwoven fabric, a binder-bonded nonwoven fabric, a knitted fabric, fabric, such as a microfiber fabric, knits, and / or a foam. According to the invention, a thermally bonded nonwoven fabric is preferably used for the cover layer. This is advantageous in that it can be dispensed with binders, so that the ability to absorb moisture and

to pass on, is preserved. The thickness of the cover layer according to ISO 9073-2 is preferably 0.1 to 2.5 mm.

Likewise preferred for the cover layer is a nonwoven fabric which is resistant to abrasion in accordance with DIN EN ISO 12947-1. As abrasion resistant applies a needle-punched nonwoven fabric for sole cover according to the above-mentioned DIN, if it survives> 25600 tours dry and> 12800 tours wet without damage.

Also preferably, a polyester and / or polyamide knitted fabric is used for the cover layer. Advantageously, the cover layer is arranged on the side of the needle nonwoven fabric which later faces the foot. The thickness of the cover layer is preferably 0.5 to 9.0 mm according to ISO 9073-2.

In addition, the insole may also have other layers.

Preferably, a foam is used as a further layer, as he the

 Moisture absorption increases again and increases comfort and damping. The foam is preferably used as an intermediate between

Needle nonwoven fabric and cover layer used. The foam is preferably a viscoelastic latex foam, a combination of viscoelastic

Latex foam and latex foam, a polyurethane foam, a

Polyethylene foam and / or mixtures thereof used.

In a preferred embodiment of the invention, needled nonwoven fabric and cover layer are bonded together with an adhesive. The foam layer can also be treated with an adhesive with the needled nonwoven and / or the

 Cover layer connected present. Alternatively, the foam layer can be coated directly onto the needled nonwoven fabric.

Another object of the invention is the use of the insole for moisture and / or climate control in the shoe.

A further subject of the invention is a process for producing an insole according to the invention, comprising the steps of: providing a fiber mixture comprising absorbent fibers and non-absorbent fibers, wherein the non-absorbent fibers comprise framework fibers and binder fibers and wherein the absorbent fibers comprise at least a portion have superabsorbent and fibrous polymers;

- carding the fiber mixture into a batt; - needling the batt to a needle felt;

 - Thermal treatment for shrinking the needle felt and

 Solidifying to needle felt;

 - Where appropriate, forming a composite layer with other layers, in particular at least one cover layer and optionally at least one foam layer;

 - thermal deformation to form the sole shape;

 - if necessary, cut out the sole shape, causing the

 Insole is obtained.

The layer composite can be formed by lamination. This includes the stacking of the desired layers and subsequent bonding. The foam layer can also be brushed directly onto the needled nonwoven and cured.

The needling is preferably carried out from above and below.

Another optional process step comprises an impregnation process for bactericidal and / or fungicidal equipment.

In the following the invention will be explained in more detail by means of an example.

A fiber blend comprising absorbent fibers and non-absorbent fibers is provided. The non-absorbent fibers include polyester fibers as framework fibers and polyester / CoPolyester core / sheath fibers as binder fibers. The absorbent fibers comprise superabsorbent fibers consisting of copolymers of acrylic acid and sodium acrylate.

From this fiber mixture a batt is carded and thermally treated. The needled nonwoven fabric obtained in this way is combined with the foam layer (viscoelastic latex foam) connected by means of polyurethane adhesive. Care should be taken here that only so much adhesive is used that no water / water vapor impermeable boundary layer through the

Adhesive is formed. This would impair the function of moisture absorption.

After curing of the adhesive, this composite is by means of a

Polyurethane adhesive bonded to a polyester knit. Here it must be ensured that only so much adhesive is used that no water / water vapor impermeable boundary layer is formed by the adhesive. This would affect the function of moisture absorption. After curing of the adhesive, this composite is assembled in roll form and is ready as a sheet for thermal deformation. The fabric is cut into narrow rolls (20cm - 30 cm wide). These narrow rollers are heated in a process in a heating channel. As a result, the core / sheath fibers are melted and thereby becomes the

Fabric deformable. After heating, the hot sheet is fed directly into a cooled negative mold of a shoe foot bed and pressed in the mold. After pressing, the deformed fabric is fed directly into a punching tool and the insole is punched out as a molded sole.

Claims

claims 1 . An insole for shoes, comprising a needle-punched non-woven fabric  contains absorbent fibers and non-absorbent fibers, wherein the non-absorbent fibers comprise skeleton fibers and binder fibers and wherein the absorbent fibers at least a proportion of  superabsorbent polymers, characterized in that the superabsorbent polymers are in fiber and / or yarn form. 2. insole according to claim 1, characterized in that the Proportion of absorbent fibers in the total weight of the needled nonwoven from 10 to 50 wt .-% is. 3. Insole according to claim 1 or 2, characterized in that the proportion of the superabsorbent fibers in the total weight of the needled nonwoven fabric of 1 wt .-% to 40 wt .-% is. 4. insole according to one or more of the preceding claims, characterized in that the proportion of binding fibers on  Total weight of the needled nonwoven fabric from 20 to 70 wt .-% is. 5. Insole according to one or more of the preceding claims, characterized in that the absorbent and the non-absorbent fibers independently of one another a length of 2 to 100 mm. 6. insole according to one or more of the preceding claims, characterized in that the needled nonwoven fabric has a basis weight of 150 to 1200 g / m ² and / or a thickness of 1, 5 to 10 mm. 7. Insole according to one or more of the preceding claims, characterized in that the later facing the foot side of the needle nonwoven fabric has a cover layer, wherein the cover layer preferably a nonwoven fabric, such as a coagulated  Microfiber nonwoven fabric, a thermally bonded nonwoven web, a binder bonded nonwoven web, a knit fabric, for example, a microfiber web, knits, and / or a foam. 8. Use of an insole according to one or more of  preceding claims for humidity and / or climate regulation in the shoe. 9. A method for producing an insole according to one or more of claims 1 to 7, comprising the following steps: Providing a fiber blend comprising absorbent fibers and non-absorbent fibers, the non-absorbent fibers comprising scaffold fibers and binder fibers, and wherein the absorbent fibers comprise at least a proportion of superabsorbent and fiberized polymers;  - carding the fiber mixture into a batt;  - needling the batt to a needle felt;  - Thermal treatment for shrinking the needle felt and Solidifying to needle felt; optionally forming a layer composite with further layers, in particular with at least one cover layer and optionally at least one foam layer;  - thermal deformation to form the sole shape; - if necessary, cut out the sole shape, causing the  Insole is obtained.