DE102017001928A1 - insole - Google Patents

Abstract

An insole for shoes comprising a needle punched nonwoven fabric containing absorbent fibers and non-absorbent fibers, the non-absorbent fibers comprising scaffold fibers and binder fibers, the absorbent fibers having at least a portion of superabsorbent polymers, and wherein the superabsorbent polymers are in fiber and / or yarn form available.

Description

The invention relates to an insole for shoes and their use for moisture / climate control in the shoe. Furthermore, a manufacturing method suitable for this purpose is specified.

A generic insole is from the DE 30 12 114 A1 known. 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 fiber mixture of 15 to 25% rayon and 75 to 85% polyester fibers. About 20% of the polyester fibers are added as shrink fibers to the base material. Great emphasis is placed on avoiding the use of adhesive material. 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 creasing and shifting in the shoe during running.

From the DE 195 25858 C1 is an insole for footwear consisting of a three-dimensionally shaped laminate of two binder-free nonwovens, wherein the foot-side nonwoven fabric is thin and abrasion resistant and the thicker, the base material of the insole-forming nonwoven fabric consists of staple fibers having a composition of 50 to 60 wt .-% Core / sheath polyester / copolyester fibers having a core component melt range of 255 to 260 ° C and sheath component of 110 to 140 ° C, 5 to 15 weight percent polyester high shrink fibers and 25 to 40 weight percent 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 Prior art known insole to further develop that the moisture absorption is improved while maintaining the high stability in use.

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 comprise skeleton fibers and binder fibers, the absorbent fibers having at least one fraction of superabsorbent polymers which are present in fiber and / or or yarn form.

Surprisingly, it has been found according to the invention that an inlay sole can be produced by the use of superabsorbent polymers in fiber and / or yarn form, hereinafter also simply called superabsorbent fibers, which has a high stability and a high and rapid moisture absorption with very rapid re-drying having. In particular, due to their fiber structure, the superabsorbent fibers can be well integrated into the needle-punched nonwoven structure, whereby the penetration from 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. Due to their excellent absorption performance, superabsorbent polymers are used according to the invention. Superabsorbent polymers are plastics that are capable of absorbing many times their own weight - up to 1,000 times - in 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 needled nonwoven fabric is preferably from 1 wt% to 40 wt%, more preferably 5 wt% to 30 wt%, and most 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 in the total weight of the needled nonwoven is from 10% to 90%, more preferably from 20% to 60%, and most 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 according to the invention are understood to mean fibers which can absorb liquid, in particular water. Preferably, the absorbent fibers have a water absorption capacity (demineralized water) at 20 ° C of at least 7 wt%, for example from 8 wt% to 20 wt%, more preferably from 10 wt%, to 30 wt%. %, on. 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 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 shell component is usually formed from polycondensation products of dicarboxylic acids such as terephthalic acid, isophthalic acid or adipic acid, with diol components such as polyethylene glycol, butylene glycol or hexamethylene glycol. Here, the melting range of the copolyester-shell component is preferably from 110 to 140 ° C and the polyethylene terephthalate core component from 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 aforementioned 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 with a linear density of from 0.9 to 80 dtex, more preferably from 1.5 to 70 mm preferably with a titer of 1.7 to 11 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 needled 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. An advantage of this is a better liquid removal.

The term needled nonwoven is to be understood in the conventional sense. In particular, a needle punched nonwoven fabric is a needle punched nonwoven fabric which has been mechanically consolidated by needle punching. 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 needle-punched nonwoven fabric is provided with a bactericidal and / or fungicidal effect by means of an impregnation process at least on the side later facing the foot.

The later facing the foot side of the insole has a cover layer in a preferred embodiment. This may comprise a nonwoven fabric such as a coagulated microfiber nonwoven web, a thermally bonded nonwoven web, a binder bonded nonwoven web, a knit fabric, fabric such as a microfiber web, 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 is possible to dispense with binders, so that the ability to absorb moisture and pass it on is retained. Preferably, the thickness of the cover layer is after ISO 9073-2 0.1 to 2.5 mm.

Also preferred is a according to the cover layer DIN EN ISO 12947-1 abrasion resistant needle punched nonwoven used. 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 it further increases the moisture absorption and increases comfort and damping. The foam is preferably used as an intermediate layer between needled nonwoven and cover layer. The foam used 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.

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

• - Bereitstellung einer Fasermischung, umfassend saugfähige Fasern und nicht-saugfähige Fasern, wobei die nicht-saugfähigen Fasern Gerüstfasern und Bindefasern umfassen und wobei die saugfähigen Fasern mindestens einen Anteil an superabsorbierenden und in Faserform vorliegenden Polymeren aufweisen;
• - Krempeln der Fasermischung zu einem Faserflor;
• - Vernadeln des Faserflores zu einem Nadelvlies;
• - thermisches Behandeln zum Schrumpfen des Nadelvlieses und Verfestigen zum Nadelvliesstoff;
• - gegebenenfalls Ausbilden eines Lagenverbundes mit weiteren Lagen, insbesondere mindestens einer Abdecklage und gegebenenfalls mindestens einer Schaumlage;
• - thermisches Verformen zum Ausbilden der Sohlenform;
• - gegebenenfalls Ausschneiden der Sohlenform wodurch die Einlegesohle erhalten wird.

A further subject of the invention is a process for producing an insole according to the invention, 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 it to the needled nonwoven fabric;
• - optionally forming a composite layer with further 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 whereby 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.

There is provided a fiber blend comprising absorbent fibers and non-absorbent fibers. 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 bonded to the foam layer (viscoelastic latex foam) by means of polyurethane adhesive. Here it must be ensured that only enough adhesive is used so that no water / water vapor impermeable boundary layer is created by the adhesive. This would impair the function of moisture absorption.

After the adhesive has cured, this composite is bonded to a polyester knit by means of a polyurethane adhesive. 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 the fabric becomes 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.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 3012114 A1 [0002]
• DE 19525858 C1 [0005, 0008]

Cited non-patent literature

• ISO 9073-2 [0035]
• DIN EN ISO 12947-1 [0036]

Claims (9)

An insole for footwear comprising a needle punched nonwoven fabric containing absorbent fibers and non-absorbent fibers, the non-absorbent fibers comprising skeleton fibers and binder fibers, and wherein the absorbent fibers have at least one portion of superabsorbent polymers, characterized in that the superabsorbent polymers are used in fiber and nonwoven fabrics / or yarn form. Insole after Claim 1 , characterized in that the proportion of the absorbent fibers in the total weight of the needled nonwoven fabric is from 10 to 50 wt .-%. Insole after Claim 1 or 2 characterized in that the proportion of superabsorbent fibers in the total weight of the needled nonwoven is from 1% to 40% by weight. Insole according to one or more of the preceding claims, characterized in that the proportion of binding fibers in the total weight of the needled nonwoven fabric is from 20 to 70% by weight. Insole according to one or more of the preceding claims, characterized in that the absorbent and the non-absorbent fibers independently of one another have a length of 2 to 100 mm. Insole according to one or more of the preceding claims, characterized in that the needle-punched nonwoven fabric has a basis weight of 150 to 1200 g / m ² and / or a thickness of 1.5 to 10 mm. 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, for example, a coagulated microfiber nonwoven fabric, a thermally bonded nonwoven, a binder bonded nonwoven fabric, a knitted fabric , Tissue, for example, a microfibre fabric, knits, and / or has a foam. Use of an insole according to one or more of the preceding claims for moisture and / or climate regulation in the shoe. Method for producing an insole according to one or more of Claims 1 to 7 composition comprising the steps of: providing a fiber blend comprising absorbent fibers and nonabsorbent fibers, the nonabsorbent fibers comprising framework fibers and binder fibers, and wherein the absorbent fibers comprise at least a portion of 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; 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 whereby the insole is obtained.