EP1524925B1 - Insole - Google Patents

Abstract

An insole (for shoes) is in the form of a disposable product having a maximum thickness of 3 mm and consisting essentially of a liquid-absorbing fiber fleece material made of or based on cellulose fiber. The insole is formed by a single wadding fleece layer ( 4 ) made of cellulose fiber material having 25% by weight of heat meltable binding fibers, the layer being compacted by means of embossing calendaring and having highly compacted embossed areas ( 9 ) as well as other areas ( 10 ) which are less compacted in comparison therewith.

Description

The invention relates to an insole for shoes as a disposable product, with a thickness of at most 3 mm, with a liquid-absorbent fiber fleece layer with or based on cellulosic fiber material. A sol sole is for example off DE 3215526 A known.

Such an insole is also made EP 0 414 634 B1 known. The insole comprises a liquid-absorbent fiber fleece layer based on cotton fibers which may also have added heat-fusible binding fibers. Furthermore, a stabilizing layer is necessarily provided, which faces the insole of the shoe and gives the sole rigidity and acts slip-resistant. On the side of the non-woven fabric layer opposite the stabilization layer, a cover layer is additionally provided. The insole 2 has a total of a plurality of holes or openings extending through all the layers.

Out EP 0 033 448 A1 is an insole made of an absorbent paper material with bactericidal and / or fungicidal and / or odor-controlling active ingredients known.

EP 0 216 727 A2 discloses and teaches an insole of at least four plies, namely a non-slip bottom foam pad, a nonwoven intermediate layer thereon, an absorbent layer of multi-ply batting material and a cover layer, again of nonwoven fabric.

A likewise multi-layered structure of a disposable Insole having a nonwoven fabric layer based on cellulose with heat-meltable polypropylene or polyester staple fibers disclosed EP 0 272 690 A2 ,

The present invention has for its object to propose an insole that is technically simple and economical to produce and which is characterized by good performance characteristics.

This object is achieved by an insole with the features of claim 1.

It has been found according to the invention that by embossing calendering only a single fiber fleece layer in the form of a cotton fleece layer according to claim 1, a sufficiently consolidated structure for use as an insole with excellent properties can be obtained. In demarcation to EP 0 033 448 A1 It should be noted that paper products, despite their designation as paper fleece, are not to be considered as nonwoven or nonwoven products in the document referred to in the definition and standard of EDANA or (ISO 9092-En2902). The definition of EDANA as of February 1999 for nonwoven or nonwoven materials excludes paper products expressis verbis.

An insole according to the invention advantageously has a thickness of 1 to 3 mm, in particular of 1.1 to 1.4 mm, wherein the thickness is determined under a test pressure of 20 g / cm ² . For this purpose and also for calculating the density from the thickness and from the basis weight of areal specimens of the embossed calendered Wattevliesschicht the specimens are previously stored for 24 hours at 105 ° C in a drying oven and then allowed to cool in a desiccator. Then they are weighed and then under the said test pressure of 20 g / cm ^{2 of} their Thickness measured. Densities of from 0.1 to 0.5 g / cm ³ , in particular from 0.2 to 0.3 g / cm ^{3, of} the emboss-calendered cotton fleece layer are preferred. The weight per unit area of the cotton fleece layer is preferably 200 to 500 g / m ² .

When embossing calendering the cotton fleece layer Kalanderpräughalzen be used with the embossment pattern forming elevations, make up their share 8 to 20%, in particular 10 to 16% of the roll surface or the surface of the insole. The engraving depth and thus the height of the elevations is at least 0.5 mm. Smallest dimensions of the elevations or of the embossing structures formed thereby from 0.3 to 0.6 mm have proven to be advantageous and preferred. It may also be punctiform structures or elongate webs in the calender roll, which then form elongated highly compressed embossed areas of a longitudinal extension of a few millimeters, in particular 2 to 6 mm in length.

The maximum tensile force in an insole according to the invention in the longitudinal direction in the dry state is advantageously 35 to 100 N / 25 mm, in particular 50 to 80 N / 25 mm and in the transverse direction 40 to 100 N / 25 mm, in particular 55 to 80 N / 25 mm. This maximum tensile force can be determined using a standardized tensile testing machine according to DIN 51221. Samples with a clamping width of 25 mm and a clamping length of 30 mm are taken from the stamped calendered cotton fleece layer to be tested. The clamped in clamping receptacles of the standardized tensile tester samples are then moved at a test speed of 100 mm / min in the plane of their extension and thereby the tensile force acting in this direction is measured. With measurements of the longitudinal and the transverse direction, which corresponds to the machine direction or the direction transverse thereto, it is advantageously possible to carry out different, in particular five individual measurements and calculate their mean value.

By the maximum tensile force is meant the maximum force at which the cotton pad tears. If previously higher force peaks are measured in the course of stretching, these represent the maximum tensile force in the sense of this test.

Furthermore, the insole according to the invention has a maximum tensile force in the wet state, which is 20 to 80 N / 25 mm, in particular 35 to 70 N / 25 mm in the longitudinal direction and 30 to 80, in particular 40 to 55 N / 25 mm in the transverse direction. To determine the maximum tensile force in the wet state, the sample in question is soaked in water and then allowed to drain for 5 seconds.

Furthermore, it proves to be advantageous that the insole according to the invention has a water absorption capacity of 1 to 4 g / g, preferably 1.5 to 3 g / g (g of liquid per gram of cotton fleece layer). In order to determine this water absorption capacity according to DIN 53923, samples of 100 mm × 100 mm are punched out of the cotton fleece layer. The samples are conditioned for a minimum of 24 hours at 23 ° C and 50% relative humidity prior to testing. Then the dry weight of the sample is determined (M1). (If a single sample weighs less than 1 g, several samples are stacked into a stack of samples that should weigh at least one gram). The sample thus obtained is placed in a wire basket and loaded with a flat steel plate (100 × 100 × 2 mm). The wire basket is immersed in the demineralized water together with the sample and the plate. The sample remains therein under the load of the plate for 30 sec. The plate is then lifted and the sample remains in the liquid for another 30 seconds without this load. The wire basket is then removed from the liquid along with the sample, and the liquid is allowed to drip over a corner for 120 seconds. The sample is then weighed again (M2). The water absorption capacity is then according to the DIN standard 53923 calculated according to (M2 - M1) / M1 x 100 in percent.

It also proves to be particularly advantageous that the insole according to the invention has a very high internal strength of> 170 N / 25 cm ² , in particular> 180 g / 25 cm ² , preferably> 190 N / 25 cm ² , which in the following It is to be checked with this method, whether and in which condition insoles are destroyed. For this purpose, a tensile testing machine according to DIN 51221, class 1 and two auxiliary sheets and double-sided adhesive tape is used. A planar circular disk-shaped sample of 57 mm diameter is glued by means of the double-sided adhesive tape between an upper and a lower auxiliary sheet, protrudes perpendicularly a clampable holding web (T-shape). The two auxiliary sheets are clamped in the tensile testing machine and then moved apart at a speed of 100 mm / min. The maximum tensile force is determined. Again, the maximum tensile force is understood as the maximum force at which the cohesion of the cotton pad is destroyed. If previously higher force peaks are measured in the course of stretching, these represent the maximum tensile force in the sense of this test.

The double-sided adhesive tape is an adhesive tape of the company 3M (Tape 410) with natural rubber as adhesive coating and a defined adhesive force of 19.3 +/- 2.2 N / 25 mm according to the German Pharmacopoeia of 1996 (there described Abziehmethode) ,

For sample preparation, a section of the above-mentioned double-sided adhesive tape is adhesively bonded at the top and bottom of the cotton fleece layer of the insole according to the invention or another sole to be tested. It is expediently first of a laminate Cotton fleece layer or insole and tape formed and then punched out of this laminate round cotton wool pads with double-sided adhesive tape. The composite thus obtained is arranged (after removal of the outer cover layers of the adhesive tape) between the two auxiliary sheets and positioned centrically. Then the auxiliary sheets are weighted with 30 kg for 2 minutes, so that the composite of insole and double-sided adhesive tape and auxiliary sheets is intimately connected. This composite is then clamped in the tensile testing machine according to DIN 51221, and at the mentioned speed of 100 mm / min, the clamps are pulled apart, thereby determining the tensile force. From at least five individual measurements, the mean value is formed and given in N.

For the reproducible performance of measurements, the adhesive strength of the double-sided adhesive tape is specified or standardized according to the abovementioned stripping method of the German Pharmacopoeia 1996. To this end, the force required to peel tapes (e.g., patches) from a flat surface at an angle of 180 ° at a constant speed is measured. Again, a tensile testing machine according to DIN 51221 class 1 is used for this purpose. There are stainless steel plates, 150 x 50 x 2 mm mechanically polished and roughened in the longitudinal direction used.

The test is carried out at 23 ° C and 50% relative humidity. Prior to this, the samples must be stored for 24 hours under these standard conditions. The steel plates are cleaned prior to starting with a cotton wool soaked in toluene, then they are contacted in a suitable container with the vapors of boiling toluene, without, however, touching the liquid directly. The resulting vapors sweep along the plate surfaces for 5 minutes. Thereafter, the plates are allowed to cool for 30 minutes in standard atmosphere.

Then strips of 400 mm length and given width of the roll of 12.5 or 25 mm are cut and applied to the cleaned metal plates so as to avoid trapped air. By means of a "tape applicator", the tape strip is rolled under a pressure of 20 N / cm sample width (the back cover paper of the adhesive tape has not yet been removed). After 10 minutes waiting time then the measurement takes place.

For measurement, the upper free end of the sample strip is knocked back and withdrawn about 25 mm from the top of the steel plate. This end of the steel plate is clamped in the upper clamp of the tensile testing machine and the struck end of the sample strip is clamped in the lower clamp of the tensile tester. The take-off angle is therefore 180 °, whereby care must be taken that the sample backs are parallel to each other, but not rub against each other. The tensile testing machine is set to a take-off speed of 300 +/- 30 mm / min.

To determine the adhesive force of the force curve is to be determined and recorded. From the force peaks obtained then the average adhesive force is evaluated according to one of the methods A) to C) described below.

In the case of deviating curves, it may be necessary to evaluate according to the procedures A or B described in the Annex. In these cases, the evaluation procedure must be included in the result information.

Evaluation method C:

This procedure is applicable if the diagram has more than 20 clearly detectable force peaks.

Condition is that the within the diagram occurring fluctuations do not occur periodically. If this is the case, evaluation procedure B should be used.

Starting from the middle of the diagram length 1, which extends from the first force peak to the demolition, four vertical lines shall be submitted at equal intervals of 1/10 of this diagram length to both sides.

These distances should be rounded to the nearest millimeter. The nine peak values closest to these lines should be used to determine the bond strength.

Individual extreme values outstanding from the curve are not taken into account in the evaluation.

The result shall be expressed as the mean of at least five tests in N / 25 mm rounded to one decimal place.

Further information is permitted.

F_i = Kraftspitzen F₁, F₂ ..... F_n
n = Anzahl der ausgewerteten KraftspitzenThe bond strength is calculated as follows: $$F=\frac{{\displaystyle \underset{i=1}{\overset{n}{\Sigma }}}{F}_i}{n}$$

F _i = force peaks F _1, F ₂ ..... _n F
n = number of evaluated force peaks

The evaluation can also be done with a suitable PC program respectively.

Evaluation method A:

This procedure is applicable when the graph shows up to five clearly distinguishable force peaks. The mean value of the values of these force peaks must be determined.

If only one peak of force occurs in the diagram, the corresponding value should be regarded as the "mean value".

Evaluation method B:

This procedure is applicable when six to ten clearly distinguishable force peaks appear in the diagram.

The peak values of the middle 80% of the diagram area starting with the first force peak and ending with the demolition are used to determine the bond strength.

As already mentioned, the above description of the adhesive strength serves to provide standardized reproducible conditions for the adhesive tape to be used in the above-described inner strength test.

It proves to be particularly advantageous that internal strengths of the insole according to the invention of> 170, preferably> 180 and in particular> 190 N / 25 cm ^{2 were} obtained. While in known multi-layer products both the layer on the upper side of the sole and the layer on the underside of the sole dissolved at inner strength values of well below 170 N / 25 cm ² , the insole according to the invention dissolved only at higher values of about 220 N / 25 on average cm ² with a standard deviation of 29 N / 25 cm ^2, the adhesive tape together with only individual fibers of the cotton fleece layer from where no layer separation could be observed.

The insole of the invention is characterized by excellent internal strength, so a good inner cohesion of the cotton fleece layer.

Furthermore, it proves to be advantageous that the insole according to the invention also proves advantageous in an abrasion test using a Crockmeter (a rubbing device) as described in DIN EN ISO 105-1212. Here, a nonwoven layer is rubbed with a defined standard test fabric. The resulting damage to the sample surfaces is assessed visually. In this case, three sections of 14 × 5 cm are taken from the fleece to be tested, with the longer side running in the machine direction. The journal of the mentioned grater is covered with the friction cloth. For this purpose, a test fabric, namely fine rib from the company Schiesser No. 4467, was used. The sample is fixed by means of retaining clips on said grater. Over a distance of 10 cm, the pin is then moved back and forth until the first lint forms. After a total of 10 scrub cycles, the first visual assessment of the sample surface is made, after 30 cycles the second evaluation follows. The load of the pin is 400 g / cm ² . When tested in the wet state, the friction fabric is adjusted to 100% moisture absorption, whereby the moistening in accordance with DIN EN ISO 105-x12.

The performance of this abrasion test showed no lint formation after 30 rubbing cycles in the cotton fleece layer of the insole according to the invention.

Figur 1

eine perspektivische Ansicht einer erfindungsgemäßen Einlegesohle;

Figur 2a

eine Draufsicht auf die Prägestruktur einer Kalanderwalze;

Figur 2b

eine Einzelheit von Figur 2a;

Fig. 3 - 5

verschiedene Oberflächenstrukturen bei erfindungsgemäßen Einlegesohlen;

Fig. 6 - 8

Draufsichten und Detaildarstellung verschiedener Oberflächenstrukturen;

Fig. 9a u. 9b

verdeutlichen den Versuchsaufbau zur Messung der inneren Festigkeit von Faservliesschichten.

Further details, advantages and features of the invention will become apparent from the appended claims and from the drawings and the following description of preferred embodiments of the invention. In the drawing shows:

FIG. 1

a perspective view of an insole according to the invention;

FIG. 2a

a plan view of the embossing structure of a calender roll;

FIG. 2b

a detail of FIG. 2a ;

Fig. 3-5

different surface structures in insoles according to the invention;

Fig. 6-8

Top views and detailed representation of various surface structures;

Fig. 9a u. 9b

illustrate the experimental setup for measuring the internal strength of non-woven fabric layers.

FIG. 1 shows in perspective view an embodiment of an insole 2 according to the invention. The insole 2 is formed from a single cotton fleece layer 4 of 50 wt .-% cotton fibers and 50 wt .-% polyethylene / polypropylene bicomponent fibers (PE / PP). The batt layer 4 is solidified by being emboss-calendered, that is, passed between a heated calender roll having projecting embossing protrusions and a counter pressure roll. In this way, the surface structure apparent from the figure was formed with punctiform and ridge-shaped embossed structures 6 in the illustrated case.

FIG. 2a shows a plan view of the corresponding structure of the calender roll in the scale 5: 1, and FIG. 2b shows a detail of the surface structure in section. The Engraving depth, ie the height of the elevations 8 on the roll surface is 0.7 mm in the illustrated case. The proportion of the elevations 8 on the roll surface, namely the so-called press surface portion is in the illustrated case about 17 to 18%.

FIG. 3 shows in plan view a FIG. 2 similar surface structure also obtained by embossing calendering in a like in FIG. 1 2. The elevations on the calender roll formed highly compressed embossed regions 9, in addition to regions 10 which are less densified. The proportion of high-density regions 9, in the total area, in this case amounts to 10 to 11%.

The FIGS. 4 and 5 show further embossed structures, which have proven to be advantageous in the production of an insole according to the invention. The pressing surface portion is at FIG. 4 about 12.5% and at FIG. 5 about 13.3%.

By the process of embossing calendering by means of a heated, aforementioned elevations 8 having calender, the heat-meltable binder fibers are partially melted at least on their surface, and it is thereby formed a thermally bonded wadding nonwoven layer. It has surprisingly been found that in this way an insole with an excellent internal strength in the sense of the definition given at the outset can be obtained, namely from above 190 N / 25 cm ² . In a known insole of the company Flawa only values of well below 170 N / 25 cm ^{2 could} be determined in the determination of the internal strength, wherein the average value is below 130 N / cm ² . In the known shoe sole, both the layer on the upper side of the sole and a layer on the underside of the sole detached, while in the insole according to the invention described above, only the adhesive tape detached together with individual fibers. A separation of the single cotton fleece layer, however, did not occur. The basis weight of the cotton fleece layer is 200-500 g / m ² . The densification of the cotton batt layer by embossing calendering is such that a density of the entire batt fabric layer between 0.1 to 0.5 g / cm ³ , preferably between 0.2 and 0.3 g / cm ³ results, the specimens in sections of 100 x 100 mm initially stored for 24 hours at 105 ° C in a drying oven and then allowed to cool in a desiccator. They were then weighed to the nearest 0.1 g. Then, in a thickness gauge under a test pressure of 20 g / cm ^2, the thickness of the specimens was measured to the nearest 0.1 mm, and then the density was calculated therefrom.

On the side facing away from the sole of the foot and the insole of a shoe facing bottom 12 of the insole 2 are very fine spaced island-shaped knobs 14 applied by screen printing or rotary printing process. These knobs are made of natural or synthetic rubber, aqueous dispersions based on acrylate or from an acrylate / latex mixture, in particular acrylate-Nitrillatex mixture or polyurethane or polyurethane-acrylate mixture or nitrile latex formed and also stand out colored from the bottom 12 of the insole. The nubs are in the case shown point or circular with a diameter of less than 1 mm. They form an anti-slip agent for the insole 2. Also line-shaped slip prevention means would be conceivable.

The insole is further impregnated with a methyl β-cyclodextrin fragrance complex solution. The solution is farnesol or another active substance, for example essential oils, aldehydes or combinations of aldehydes which have a deodorizing effect, a deodorizing ester of aromatic alcohols and aromatic carboxylic acids having antimicrobial activity. Such an active ingredient may also be complexed together with the perfume and the mentioned methyl-β-cyclodextrin if, as in the case of farnesol, it can easily volatilize.

To reduce the tendency of athlete's foot to form, the complex solution may contain a fungicidal active ingredient, e.g. Undecylenamide (DEA) can be added.

If, in the case shown, the fragrance is incorporated in the form of methyl-β-cyclodextrin complexes, this prevents the rapid volatilization of the fragrance and ensures a long-lasting fragrance. The fragrance is released from the methyl-β-cyclodextrin complexes when heat, moisture (foot sweat) is added and the shoes are pulled off. There is then advantageously the ability to complex the organic constituents of the foot perspiration on the released cyclodextrin molecules, especially during drying of the shoe sole. It can be prevented in this way the emergence of unpleasant odor.

The addition of farnesol or another antimicrobial agent inhibits the action of those bacteria which decompose the foot sweat and thus trigger the sweat odor. It should be noted that the addition of the above-mentioned means can be used independently of the concrete embossing structure 6 of the insole 2 in each insole according to the invention.

It proves to be particularly advantageous that the insole according to the invention is formed from the mentioned single wadding nonwoven layer 4 and no foot facing further cover layer is provided. This way you can thin yet non-fluffing (abrasion test) and high internal strength product.

The FIGS. 6, 7 and 8 show different surface structures in the insole according to the invention, wherein it is at FIG. 6 around a surface texture like in FIG. 3 shown acts. The surface structure after FIGS. 7 and 8 differ slightly from this. The arrangement and dimensioning of the highly compressed embossed regions 9 and of the less densely compressed regions 10 can also be seen in an enlarged detail.

Further shows FIG. 9 schematically the experimental design of the test method described above for internal strength of the cotton fleece layer or the insole. One recognizes the disk-shaped specimen of the Wattevliesschicht 4, and adjacent thereto each of the double-sided adhesive tape 20 and the auxiliary sheets 22, which are clamped with their protruding web 24 in clamp receivers 26 of the tensile testing machine.

According to a preferred embodiment of the described shoe sole 2 according to the invention of said composition, the only cotton fleece layer 4 has been embossing calendered under an embossing pressure of 400 N / mm. Based on a weight per unit area of 303 g / m ^2, this results in a nonwoven thickness in the embossed calendered state of the insole of 1.28 mm. A maximum dry tensile strength of 54.6 N / 25 mm in the longitudinal direction and 68.9 N / 25 mm in the transverse direction was determined. The water holding capacity was 1.7 g of liquid per g of cotton fleece layer.

Exactly the same measurements were then carried out in an insole, which was also acted upon in the manner described above with a fragrance mixture and have the nubs described 14 at the bottom 12. The determined basis weight in this case was 338 g / m ² . The nonwoven thickness was measured at 1.22 mm. The values determined for the maximum tensile force were 49.9 N / 25 mm in the longitudinal direction and 63.7 N / 25 mm in the transverse direction. The values in the wet state were 36.0 N / 25 mm in the longitudinal direction and 47.0 N / 25 mm in the transverse direction. The water holding capacity was 1.8 g / g. The mean value of at least 5 measurements was taken in each case.

Claims (13)

1. Insole (2) for shoes designed as a disposable product having a thickness of at most 3 mm and with a liquid absorbing non-woven fiber layer including or based on cellulose fiber material, characterized in that the sole is made from one single wad fleece layer (4) having a cellulose-type fiber material with at least 25 % per weight of heat meltable binding fibers, the layer being strengthened by calendar embossment and having highly compressed regions with high density of embossments (9) as well as regions (10) of less embossment density.
2. Insole according to claim 1, characterized in that its thickness is 1 - 3 mm, in particular 1 - 2 mm.
3. Insole according to claim 1, characterized in that its density is 0.1-0.5 g/cm³, in particular 0.2-0.3 g/cm³.
4. Insole according to any one of the preceding claims, characterized in that the highly compressed embossed regions (9) correspond to a fraction of 8 - 20 % of the surface of the fiber fleece layer (4).
5. Insole according to any one of the preceding claims, characterized in that the highly compressed embossed regions (9) have a depth of at least 0.5 mm and a smallest dimension in the planar direction of 0.3 - 0.6 mm.
6. Insole according to any one of the preceding claims, characterized in that the maximum tensile force of the wad fleece web (4) in the dry state and in the longitudinal direction assumes values of 35-100 N/25 mm and of 40-100 N/25 mm in the transverse direction.
7. Insole according to any one of the preceding claims, characterized in that the maximum tensile pressure of the wad fleece web (4) in the moisten state assumes values of 20-100 N/25 mm in the longitudinal direction and of 30-80 N/25 mm in the transverse direction.
8. Insole according to any one of the preceding claims, characterized in that it has a water retention or acceptance capacity of 1-4 g liquid per g of fiber fleece layer.
9. Insole according to any one of the preceding claims, characterized in that it has an internal strength of > 170 N/25 cm², preferentially of > 180 N/25 mm².
10. Insole according to any one of the preceding claims, characterized in that the wad fleece layer (4) includes cotton fibers.
11. Insole according to any one of the preceding claims, characterized in that it has heat meltable binding fibers, in particular multi-component fibers, polyethylene (PE) and/or polypropylene (PP) and/or polyester (PES).
12. Insole according to any one of the preceding claims, characterized in that it is provided with island shaped or linear shaped slippage prevention means (14) on the lower side (12) of the insole (2) facing the insole of a shoe in the state of use.
13. Insole according to claim 12, characterized in that the slippage prevention means (14) have a maximum size of at most 1.5 mm, in particular of at most 1 mm.

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