DE3917791C2 - - Google Patents

Description

The invention relates to a nonwoven material, in particular a composite nonwoven material with at least two layers according to the preamble of claim 1.

Such nonwoven materials are made according to the known spinning Nonwoven process made and serve to liquid To be transported in one direction from the outside inwards animals, with a storage body or an inside Absorbent body, which is through the nonwoven material transported liquid absorbs and stores.  

A preferred application of such a nonwoven mat rials is in diapers for children or also in continent diapers given for adults. Known Lich such diapers include an absorbent body on one side facing out with a polymer foil is covered to the exit of the in the suction to prevent body-stored fluid. On its other inner use side is the suction body with the fleece used here as a covering fleece material covered with synthetic fibers, the are in themselves hydrophobic. This is how it works Non-woven material, i.e. the covering fleece, even then dry if the absorbent body with a diaper Urine is soaked.

In order to adequately absorb urine rapid transport of the liquid to the absorbent body To ensure, it is known that the hydrophobic Ab to provide cover fleece with suitable wetting agents, like this for example in the German interpretation Scripture 27 22 860 is described. Through the order against a wetting agent, i.e. by hydrophilizing of the nonwoven material, the previously hydrophobic Ab cover fleece now permeable to water.  

However, it must be ensured that the up Carrier of the wetting agent controlled in a certain way must become. An order that is too strong will accelerate the transport of urine to the absorbent body, however, be then there is a risk that the spit in the absorbent body urine transported back to the outside can affect the feeling of dryness is pregnant.

On the other hand, a complete waiver or one too weak application of the wetting agent to the cover as a result, the urine is not fast enough is transported to the absorbent, which makes it desired feeling of dryness also affected becomes.

Basically, the hydrophilization of the in itself hydrophobic non-woven material is not difficult speed, however, the convenience of the so prepared Nonwoven material still leaves something to be desired in practice.

The invention has for its object a fleece to create material of the required kind, wel ches an improved liquid transport in allows a preferred direction and at the same time an undesired return transport of the liquid  prevented.

This object is achieved by the invention in the upper Concept of claim 1 nonwoven material by the characteristics of the characterizing part of the An saying 1.

While it is provided in the prior art that Non-woven material to be fully hydrophilized and with to provide a wetting agent and thus also on the to make the entire surface permeable to water, be The invention surprisingly follows the path that Nonwoven material only on a variety of discrete, of each other at separate hydrophilized sites to train casually. On the nonwoven material, so to speak generated a pattern with discrete digits, where only these discrete areas are permeable to water, while the rest of the surface area of the fleece terials remains hydrophobic.

The invention is based on the knowledge that in one Non-woven material hydrophilized over the entire surface there is a risk that the ge in the storage body stored liquid back through the nonwoven material can be transported if the storage body is a  Maximum liquid has absorbed and itself has soaked up.

With such a full absorbent is on the Stel len, at which further liquid is supplied, a local saturation is present because the absorbent is not is still receptive. Such a local saturation can also result from the fact that at a certain Place too much liquid directed to the absorbent and it is unable to hold the liquid due to wicking quickly enough within the to distribute the entire absorbent body.

At pressure points, as they occur during the movement of the Surrendered to the user's diaper again and again then the danger that the liquid might get through that the fleece material is transported back, which affects the feeling of dryness becomes.

In the embodiment of the nonwoven material according to the invention terials with a variety of discrete hydrophilizing th and water-permeable points In contrast, largely avoid the disadvantage. Through the many hydrophilized areas of the nonwoven material follows when the nonwoven material is covered with urine  is already a distribution of the liquid on the Nonwoven material, with the result that the penetration or the liquid transport only on the existing ones discrete places and does not happen over the entire area. As has been shown in experiments, this results by a surprising increase overall Suction capacity and also an increased Absorbtionsge speed for the liquid.

Another advantage is that the targeted fluid at discrete locations transport the absorbent body only in discrete places is supplied with liquid, and that the absorbent body due to its wicking (suction) ability is the liquid supplied to it in discrete places better ver to its entire cross-sectional content share. The danger of the diaper user the moisture feeling of the Nonwoven material is largely eliminated.

In an expedient embodiment of the invention the hydrophilized water-permeable areas punctiform or circular, rectangular or also Form stripes. It is ent in any case deciding that the nonwoven material is not all over,  but only locally at discrete locations separate places is water-permeable.

In a further advantageous embodiment of the Invention is the nonwoven material with two layers an upper outer layer of relatively coarse fibers (Coarse layer) and a lower one, the absorbent nifty inner layer (fine layer) with finer Fibers formed.

About the cross-section of this two-layer fleece materials is thereby in terms of diameter of the fibers of the individual layers knife gradient formed. This fiber diameter gradient provides a dish in the desired way liquid transport towards the outside layer down over the inner layer for suction body because of fluid retention and the transport speed of the rough outer layer are less than that of the inner fine layer.

If, incidentally, the disadvantage of the invention Return of the liquid from the absorbent body externally avoided, this is due to the to bring back novel formation of the nonwoven material  ren, which is not full area, but only on one Variety of discrete areas is hydrophilized. In the case of a full absorbent body, the reverse trans port on an overall smaller area level borders as if - like this with the well-known fleece material is provided - the entire area of the Nonwoven material is hydrophilized.

The upper outer layer can be used as a spacer be considered as the outer layer because of their rough structure only to a small extent for storage of liquid is suitable.

The design of the nonwoven material according to the An saying 1 fulfills the function of a distribution the liquid and ensures a quick penetration ren of the liquid to the absorbent body.

According to a further expedient embodiment of the Invention is the multitude of discrete hydrophi water-permeable areas not over the distributed over the entire area of the nonwoven material, but only within a window Surface area provided while the area remains hydrophobic outside the window.  

This configuration of the nonwoven material allows even better targeted control of the wetting agent order and liquid transport to the desired areas. Based on the total area che of a diaper, it is sufficient if the Ab Deckvlies only about 6-50% with the window is provided with the discrete hydrophilized areas. It is assumed that in practice - especially with diapers - the liquid does not of the entire outer surface, but only in certain areas occurs and must be transported to the absorbent. Otherwise, this embodiment of the invention achieved that the urine leaking from the user targets sucked up and in the area of the with the hydrophi the parts provided with the parts quickly to the absorbent body can be transported by.

Through the wicking of the absorbent body Then urine drained on all sides, and also to such areas, above de The nonwoven material is still hydrophobic is formed. Experiments have shown that the tendency of adverse repatriation significantly restricted by urine  can be because in those areas where the fleece material or the cover fleece as before such a return transport is practical is completely excluded.

The selected area, which is the area with specifies the discrete hydrophilized sites, can preferably in the form of a strip in the middle a disposable diaper may be provided. It is in everyone Case sufficient if in with the folded diaper in the middle of the step a strip with the hydro PhD positions. With a professional the width of the diaper is enough to match that of the schma len web.

In a further expedient embodiment of the invention are the discrete water permeable areas through Printing the nonwoven material with a wetting agent generated. In this way, the discrete Realize the process in a simple manner ren. It is also possible to discrete the water through casual spots by an intermittent check hen the fleece material with a wetting agent put.  

In another appropriate embodiment of the Er are the discrete, water-permeable stel len through holes made in the nonwoven material formed with the holes on their outer edges with are wetted with a wetting agent.

This way of producing the discrete water-permeable points can be carried out in a simple manner with a spiked roller provided on its circumference with spikes known for other purposes. The fleece material is guided over the spiked roller, the spines of which then produce the holes, preferably 5-50 holes per cm ^{2 being} provided.

The spikes are ver with a wetting agent order see, so that then when creating the holes in the Fleece material the outer edges of the holes with the Wetting agents are affected.

In a further expedient embodiment Relief and for the comfort of the user and provided by the processor, the individual discrete make water-permeable areas visible in color, e.g. B. by adding a color to the wetting agent is.  

Other advantageous developments and Ausgestal Cations of the invention result from the Unteran sayings, as well as the following description.

Based on the design shown in the drawing The invention will be described in more detail below explained. Show it:

A plan view of a diaper in which a FLAE chenbereich of Abdeckvlie ses is provided with a plurality of discrete locations wasserdurchlässi gen Fig. 1,

Fig. 2 is a partial view are formed as plan view of a diaper in which the discrete sites of the water-permeable covering web through holes,

Fig. 3 is a schematic cross-sectional view of a diaper according to Fig. 2,

FIG. 4 shows a further schematic cross-sectional view in a different scale of a diaper according to FIG. 2, and

Fig. 5 shows another embodiment of a nonwoven material.

In Fig. 1, a diaper 10 is shown as a plan view in a schematic view, which in a manner known per se has an absorbent body 24 (see. Fig. 3), which cher in a known manner and not shown here on its back with a water-impermeable polymer film is surrounded to prevent leakage of the liquid stored in the absorbent body 24 speed.

A cover fleece 12 is provided as the fleece material on the side of the absorbent body 24 opposite the polymer film mentioned, ie on the user side. This covering fleece 12 is formed by hydrophobic fibers and extends over the entire surface area of the diaper 10 .

Within a region formed by a window 14 , a large number of discrete, hydrophilized and thus water-permeable points 16 are arranged, which are formed by applying a wetting agent at the respective points 16 .

As such, these hydrophilized water-permeable points 16 are not visible, but for better clarification of the invention these points are shown hatched in the drawing. For the rest, an advantageous embodiment of the invention provides for these hydrophilized areas 16 to be made visible to the user by means of a color.

While in Fig. 1, the hydrophilized water-permeable bodies 16 are formed by small rectangles, illustrates Fig. 2 an embodiment in which the hydrophilized points 16 are formed by a plurality of holes, with preference as 5-50 holes per cm ² let it be realized.

In the cross-sectional view of a nonwoven material designed as a cover nonwoven 12 according to FIG. 3, these holes 26 are shown in a schematic view. For reasons of better clarity of the drawing, the Saugkör is shown by 24 at a distance from the cover fleece 12 .

The cover fleece 12 has a two-layer structure with a coarse outer layer 18 and an inner fine layer or inner layer 20 . From the cover nonwoven 12 is here formed as a composite nonwoven material with two layers.

The holes 26 shown are provided on their outer edges 28 with a wetting agent. The outer layer 18 here consists of continuous fibers with an average diameter of 10-30 microns. The inner layer here also consists of continuous fibers with an average diameter of 4-10 µm. In a further embodiment of the invention, the inner layer can also be formed by short finite fibers with an average diameter of 1-5 μm.

As can be seen in Fig. 3, the outer layer 18 and the inner layer 20 are separated by a functional boundary 22 shown as a broken line. As a result of the rough structuring of the outer layer 18 and the fine inner layer 20 with the thinner fiber diameters, a fiber diameter gradient is formed over the entire cross section of the cover fleece 12 , which enables a liquid to be transported in the direction of the absorbent body 24 .

To further clarify the invention, an area with water 30 is shown in FIG. 3 on the upper outer layer 18 . Due to the effect of the large number of individual discrete hydrophilized spots in the form of the holes 26 , a distribution of the liquid supply of the water 30 on the surface of the covering fleece 12 on the holes 26 already takes place in the manner illustrated by the arrows.

Below the holes 26 spatially limited water accumulations 32 form in the area of the holes 26 within the absorbent body 24 . From each of these water accumulations 32 is - as indicated by the arrows - the liquid by the known wicking action of the absorbent body 24 divides ver.

To further clarify the invention, FIG. 4 shows a schematic cross-sectional view of the two-layer cover fleece 12 with the outer layer 18 and the inner layer 20 , which are connected to one another in a manner known per se at the fastening points 34 by thermal welding. Here too, the functional limit 22 can be seen.

The only partially and to simplify the drawing representation not drawn to scale th holes 26 extend through the outer layer 18 and the inner layer 20th

These holes 26 can be produced, for example, with a spiked roller (not shown here) provided with spikes on its outer circumference. The diameter of the holes is so small with 0.2-2 mm that the holes 26 as such are not necessarily visible in the upper coarse outer layer, while they actually penetrate the lower fine layer or inner layer 20 due to the finer structure.

As a further embodiment, Fig. 5 shows a schematic representation of a cross-sectional view of a two-layer cover fleece with an outer layer 18 and an inner layer 20 which faces the absorbent body not shown here.

The entire surface of the cover fleece 12 is here hydrophilized and thus made water permeable overall, while only the lower inner layer 20 is hydrophilized at a plurality of discrete locations 16 , for example through the holes 26 already mentioned.

Although in this embodiment the upper outer layer 18 is water-permeable over the entire surface, the advantages sought by the invention can also be achieved here because of the underlayer hydrophilized only at discrete points.

Claims (16)

1. Nonwoven material, in particular composite nonwoven material with at least two layers, for a liquid or moisture transport in a preferred direction and a storage body for the liquid covered by the nonwoven material on its suction side, where the nonwoven material originally forms hydrophobically and then through Treatment is hydrophilized, characterized in that the nonwoven material ( 12 ) is water-permeable only at a multiplicity of discrete, separate, hydrophilized points ( 16 ). 2. Nonwoven material according to claim 1, characterized in that only a selected area ( 14 ) of the total area of the nonwoven material ( 12 ) is provided with the hydrophilized points ( 16 ). 3. Nonwoven material according to claim 1 and / or 2, characterized in that the hydrophilized Stel len ( 16 ) are circular or point-shaped or in a freely selectable geometric shape. 4. Nonwoven material according to claim 1 and / or 2, characterized in that the hydrophilized Stel len ( 16 ) are rectangular. 5. nonwoven material according to claim 1 and / or 2, characterized in that the hydrophilized Stel len are strip-shaped. 6. Nonwoven material according to one of the preceding claims 1-5, characterized in that the nonwoven material ( 12 ) is formed in two layers with an upper outer layer ( 18 ) made of coarse fibers and a lower inner layer ( 20 ) with finer fibers. 7. Nonwoven material according to claim 6, characterized in that the outer layer ( 18 ) is hydro philately, while the inner layer ( 20 ) is permeable to water only at discrete locations ( 16 ). 8. Nonwoven material according to claim 6, characterized in that the outer layer ( 18 ) and the inner layer ( 20 ) are permeable to water together at discrete locations ( 16 ). 9. Nonwoven material according to one of the preceding claims 1-8, characterized in that the discrete water-permeable points ( 16 ) are produced by printing the nonwoven material ( 12 ) with wetting agent. 10. Nonwoven material according to one of the preceding claims 1-8, characterized in that the discrete water-permeable points ( 16 ) are produced by intermittent spraying with wetting agent. 11. Nonwoven material according to one of the preceding claims 1-8, characterized in that the discrete water-permeable points ( 16 ) are produced by small holes ( 26 ) made in the nonwoven material ( 12 ), which are provided on their outer edges ( 28 ) with a wetting agent are wetted and which partially or completely penetrate the nonwoven material. 12. Nonwoven material according to one of the preceding claims 1-5, characterized in that the nonwoven material ( 12 ) is designed as a single-layer cover fleece (cover stock) of a diaper ( 10 ), a sanitary napkin or other incontinence products. 13. Nonwoven material according to one of the preceding claims 6-12, characterized in that the discrete hydrophilicized areas ( 16 ) are made visible in color. 14. Nonwoven material according to one of the preceding claims 6-11 or 13, characterized in that the fibers of the coarse outer layer are continuous fibers and have an average diameter of about 10-30 µm and that the fibers of the fine inner layer ( 20 ) are predominantly continuous fibers and have an average diameter of about 4-10 µm. 15. Nonwoven material according to claim 14, characterized in that the fibers of the inner layer ( 20 ) are finite and / or infinite fibers with an average diameter of about 1-5 microns. 16. Nonwoven material according to claim 11, characterized in that the average diameter of the holes ( 26 ) are approximately 0.2-2 mm.