DE4321155A1 - Sheet-like, non-woven fibrous layer material for insertion in hygiene articles - Google Patents

Abstract

A sheet-like, non-woven fibrous layer material, in particular a nonwoven fabric, is intended for use in hygiene articles such as sanitary towels. The fibrous layer material (nonwoven layer 1) has liquid-transporting properties in the direction of its thickness (D). At least one surface (2) of the fibrous layer material (nonwoven layer 1) is provided with protuberances (3) that project from the surface (2), are made of a liquid-impermeable material and have passage regions (passage openings 5) for passage of liquid between them. <IMAGE>

Description

The invention relates to a flat, non-woven fiber layer material, in particular made of nonwoven fabric, tissue or the like for use in hygiene articles, especially in sanitary napkins, which fiber layer material at least in its direction of thickness has liquid-transporting properties.

Nonwoven fibrous sheet materials are commonly used e.g. B. as kör Persistent cover layers used on the absorbent pads of sanitary napkins. Such cover layers are characterized by skin friendliness and tactile Softness, however, are in their back-wetting properties and the visual len opacity in need of improvement.

Alternatively, cover layers for sanitary napkins can also be made from a two- or three-dimensional, perforated plastic film consist of a de Finished, qualitatively adjustable ratio between closed, d. H. hydrophobic or liquid-impermeable surface and perforated, has liquid-permeable surface. Such cover layers have with regard to rewetting and visual covering power compared to nonwovens with open fiber structure significant advantages. This is based u. a. represents on, at least with three-dimensionally perforated foils that are on their Have protruding opening cones on the suction body side, a so-called "Ab stand holder effect "between the absorbent and the top of the Ab top layer is caused, which reduces rewetting. Such a hole However, films do not have the skin familiar from nonwoven cover layers friendliness and tactile softness.

The invention has for its object a flat, non-woven Specify fiber layer material for use in hygiene articles, the under  Maintaining its skin friendliness and tactile softness improved Back-wetting properties and a significantly increased visual covering power body fluids located below the layer material shows.

This object is achieved by the in the characterizing part of claim 1 given characteristics solved. By applying the from the surface of the fiber layer material protruding from liquid-impermeable casual material is on the one side of this surface the one achieved "spacer effect" mentioned above and on the other hand the open Partially closed fiber structure of the fiber layer material, so that in Connection with the "spacer effect" further reduces the rewetting is decorated. Since the surface facing away from the elevations is opposite conventional cover layers made of fiber layer material practically unchanged remains, skin friendliness and tactile softness are maintained.

Claims 2 to 5 characterize advantageous configurations for the Elevations that also appeal to the fiber layer material aesthetically Give appropriate or functional appearance.

According to claims 6 and 7, the surveys on the fiber la gene material preferably printed using the screen printing process. Screen printing is advantageous since this is a printing technique by means of which printing is carried out even on a relatively uneven surface, such as this. B. in a nonwoven fabric material due to the tangle of the fibers is.

The claims 8 to 10 give advantageous materials for the surveys at. It should be emphasized that the rewetting properties continue by appropriate adjustment of the hydrophobic or hydrophilic Properties of the polymer material used can be optimized.

The height of the elevations from the upper specified in claim 11 surface of the fiber layer material is sufficient to the "Ab  stabilizer effect "to ensure states that the distance between the fiber sheet material and one under located absorbent z. B. a sanitary napkin, is small enough to when body fluid runs onto the body-side surface of the Fiber layer material a rapid liquid transport through this to achieve through to the absorbent. When rewetting from the suction body, which due to its suction behavior leads to a lower liquid volume, the one caused by the surveys is sufficient Distance between the absorbent and the fiber layer material that the Liquid return transport is significantly reduced.

Claims 12 and 13 relate to different embodiments a sanitary napkin in which an inventive fiber layer material as body-side cover layer or intermediate layer between such a body personal cover layer and the absorbent body is used. Such Hygiene articles and especially sanitary napkins have a skin on the one hand friendly and soft body-side surface, on the other hand strong improved rewetting properties.

Further features, details and advantages of the invention are according to following description can be seen in the embodiments of the Er invention explained in more detail with reference to the accompanying figures become. Show it:

Fig. 1 is a photocopy of a micrograph of a fiber sheet material according to the invention,

Fig. 2 position is a partial vertical section through a sanitary towel according to the invention with a fiber sheet material as a body-side covering,

FIGS. 3 and 4 are respectively a partial vertical section of sanitary napkins having an inventive fibers sheet material as an intermediate layer between the body-side cover layer and absorbent body in two difference of embodiments and

Fig. 5 to 12 are schematic plan views of the invention Fasernla genetic materials with different configurations of its It surveys.

As is clear from FIGS. 1 and 2, a flat, non-woven fiber layer material according to the invention consists of a nonwoven layer 1 , which is a commercially available, thermoset polypropylene carding nonwoven with a basis weight of 20 g / m² . Alternatively, for example, a thermoset polypropylene spunbonded nonwoven with a basis weight of 16 g / m² or a polypropylene carded nonwoven with a basis weight of 26 g / m² can be used, which has been consolidated by a so-called "hot-through-air process" .

Such nonwovens have liquid-transporting properties in the direction of thickness D ( FIG. 2).

On the viewer of FIG. 1 facing surface 2 of the nonwoven fabric layer 1 , elevations 3 in the form of individual, grid-like knobs 4 are applied by means of screen printing technology. These knobs 4 are made of a liquid-impermeable material, such as, for example, a hot-melt adhesive (hot melt) specially developed for screen printing, as is given by hot-melt adhesive with the designation Lunatac D 014BD2 or BD4 from Fuller. Commercially available ethylene / vinyl acetate polymer dispersions, for example the designation Vinapas EN 426 (hydrophilic) or Vinapas EN 428 (hydrophobic) from Wacher, are also suitable for the surveys 3 .

Due to the grid-like arrangement of the individual knobs 4 remain between these areas in which the open fiber structure of the nonwoven layer 1 is retained. The areas located between the knobs 4 bil the passage openings 5 for a liquid passage.

A screen type with a mesh size of 25 mesh was used for the screen printing of the knobs 4 . This results in 120 knobs / cm², whereby
the knob diameter ⌀ ( Fig. 1) is about 0.6 mm. The coverage ratio of the knob surface to the total surface of the nonwoven layer 1 be 46%. The knob height h ( Fig. 2) is 176 µm. The applied amount of hot melt adhesive is 58 g / m².

These results as well as corresponding results for sieve types with a Mesh sizes of 11.2 and 40 mesh are shown in Table 1 below listed.

Table 1

Nonwoven: PP carded nonwoven thermally bonded, basis weight 20 g / m², surveys: Lunatac D 014BD2, hot melt adhesive

As is clear from Fig. 2, the nonwoven fabric layer 1 according to the invention can be used with its knobs 4 as a body-side cover layer 6 of a sanitary napkin, the non-knobbed surface 7 of the cover layer 6 facing the outside, that is to say the body side, of the bandage. Since the cover layer 6 retains its skin friendliness and tactile softness.

By the inner on the surface 2 of the nonwoven fabric layer 1 attached burls 4, the nonwoven fabric layer 1 is held by the absorbent body 8 of the sanitary napkin at a distance ( "spacer effect"), so that the nonwoven layer is 1 rückgenäßt in significantly reduced extent during use of the sanitary napkin. This effect is further supported by a hydrophobic design of the material used for the knobs 4 , since body fluid emerging from the absorbent body 8 is repelled downward as a result.

The improved rewetting properties were compared which can be described as follows:

Test liquids used:

- Defibrinated sheep blood
- blood replacement fluid
Recipe:
14 g tylose (CMC, Hoechst)
10 g NaCl
4 g NaHCO₃
100 g glycerin

The solution is made up to 1000 ml with distilled water. The Viscosity at the Epprecht Rheomat is 13.0 mPas.

- urine replacement fluid
Recipe:
Urea 21.4 g
NaCl 3.0 g
K₂SO₄ 2.3 g
Citric acid 0.3 g
MgCL₂ 0.2 g
CaCl₂ 0.1 g
L-histidine-HCL 0.5 g
Bovine serum albumin 0.1 g
(NM₄) ₂HPO₄ 2.0 g
pH: 6.0

A cellulose flake absorbent from the following Spe certification used:

Weight: 8.9 g
Length: 218 mm
Width: 59 mm
Thickness: 19 mm
Density: 0.05-0.07 g / cm³

This absorbent body was made with a thermally bonded PP card nonwoven with a basis weight of 20 g / m² with and without printed hot hot-melt adhesive knobs with knobs directed towards the absorbent body covers.

In the rewet test, 5 ml of test liquid with a temperature from 37 ° C to the weighed test specimen using a burette in a Time of 20 seconds applied with the buret tip in contact with the specimen surface is. After a waiting time of 10 minutes, Weighed a stack of filter paper from at least 10 individual layers and placed on the test specimen. This arrangement is with a cuboid mass body of 5 kg and the base of 110 × 110 mm² for Charged for 15 seconds. The stack of filter paper is then weighed again and with the lowest layer of paper, the back wetting surface is planimetric averages.

The measured quantity and the rewetting factor are calculated according to the following Definitions calculated:

Rewet amount = weight of wet filter paper stack - weight of dry filter paper stack
Rewetting factor = rewetting amount × rewetting area.

The test results by means of this rewetting test can be found in tables 2 and 3 following this description. It follows directly from this that the rewetting properties improve considerably through the printed elevations on the nonwoven layer 1 . The test results listed in Table 2 in the three right-hand columns (Mesh 11, 2, 25 and 40, respectively) were obtained with an experimental setup which corresponds to the sanitary napkin configuration according to FIG. 2.

The test setup on which Table 3 is based corresponds to the construction of a sanitary napkin shown in FIG. 4, where a nonwoven fabric layer 1 'according to the invention is used as an intermediate layer between a cover layer 9 made of conventional thermosolidified PP carded nonwoven fabric with a weight per unit area of 20 g / m 2 and the absorbent body 8 is. This nonwoven layer 1 'has on its surface 9 facing the surface 2 ' knobs 4 of hot melt adhesive, which were applied by means of screen printing with a screen of 25 mesh. The PP nonwoven fabric of the nonwoven layer 1 'is of the same quality as that of the cover layer 9 .

By the "spacer effect" achieved by means of the knobs 4 between the cover layer 9 and the nonwoven layer 1 ', the rear wetness properties are again significantly improved, as can be seen clearly from the values in Table 3.

Another possible embodiment of a sanitary napkin is shown in Fig. 3 ge. Here, a conventional PP nonwoven fabric with 20 g / m² basis weight is used as the cover layer 9 . Below this is a tissue layer 10 , which in turn is printed on its surface 2 facing the absorbent body 8 with the knobs 4 .

In Figs. 5 to 12 different embodiments are illustrated for the He surveys 3, wherein these elevations appear solid black 3, while the white areas therebetween mark the nonwoven layer 1 itself and therefore the passage openings 5.

The nonwoven layer 1 shown in Fig. 5 corresponds substantially to the layers of nonwoven fabric 1 shown in Figs. 1 and 2.

In the exemplary embodiments according to FIGS. 6, 8, 9 and 11, the elevations 3 form lattice-shaped structures, circular through openings 5 being provided according to FIG. 6. In the exemplary embodiments according to FIGS. 8 and 11, the webs 11 that realize the elevations 3 form passage openings 5 between them, which openings are hexagonal in plan view. In FIG. 8, the through openings 5 are arranged in linear rows, whereas in the embodiment according to FIG. 11 a honeycomb-like structure is achieved.

In FIG. 9, the webs 11 form a diamond-shaped pattern between them, arranged in an orderly manner through passage openings 5 .

In Figs. 7 and 12 individual elevations 3 are again provided, which are designed hexagonal in plan view. Their arrangement is again made in linear rows ( Fig. 7) or honeycomb-like ( Fig. 12).

Fig. 10 shows individual surveys 3 , which are arranged diamond-shaped, grid-like.

Table 2

Back-wetting properties of thermoset PP card nonwoven with Weight 20 g / m² with and without hot melt adhesive screen printing. Use as a covering nonwoven.

Screen printing dot size (mesh)

Table 3

Back-wetting properties of thermally bonded PP carded nonwoven composite: PP cover fleece, basis weight 20 g / m² / PP fleece of the same quality with hotmelt print 25 mesh, print on the cover fleece side / fluff absorbent body

Claims (13)

1. Flat, non-woven fiber layer material, in particular made of nonwoven, tissue or the like. For use in hygiene articles, in particular in sanitary napkins, which fiber layer material has liquid-transporting properties at least in the thickness direction (D), characterized in that on at least one surface ( 2 ) of the fiber layer material (nonwoven layer 1, tissue layer 10) from the surface ( 2 ) protruding elevations ( 3 ) made of liquid-impermeable material are applied, which elevations ( 3 ) have passage areas (passage openings 5) between them for liquid passage. 2. fiber layer material according to claim 1, characterized in that the elevations ( 3 ) consist of individual, preferably grid-like arranged Nop pen ( 4 ). 3. fiber layer material according to claim 2, characterized in that the knobs ( 4 ) are circular or polygonal in plan view, in particular diamond-shaped or hexagonal. 4. fiber layer material according to claim 1, characterized in that the elevations ( 3 ) consist of continuous webs ( 11 ) forming a lattice-like structure in plan view. 5. Fiber layer material according to claim 4, characterized in that the through openings ( 5 ) formed between the webs ( 11 ) are circular or polygonal, in particular diamond-shaped or hexagonal, in plan view. 6. fiber layer material according to one of claims 1 to 5, characterized in that the elevations ( 3 ) on the fiber layer material (non-woven fabric layer 1, tissue layer 10) are printed. 7. fiber layer material according to claim 6, characterized in that the elevations ( 3 ) are printed in the screen printing process. 8. fiber layer material according to one of claims 1 to 7, characterized in that the elevations ( 3 ) consist of hydrophobic or hydrophilic polymer material. 9. fiber layer material according to claim 8, characterized in that the elevations ( 3 ) consist of an ethylene / vinyl acetate polymer dispersion. 10. fiber layer material according to claim 8, characterized in that the elevations ( 3 ) consist of a hot melt adhesive. 11. Fiber layer material according to one of claims 1 to 10, characterized in that the elevations ( 3 ) have a standing height (h) from the upper surface ( 2 ) of the fiber layer material (nonwoven layer 1, tissue layer 10) of 50 to 300 microns. 12. hygiene article, in particular sanitary napkin, with an absorbent body ( 8 ) and a body-side cover layer (nonwoven layer 1) on the absorbent body ( 8 ), characterized in that the cover layer (nonwoven layer 1) is formed by a fiber layer material according to one of claims 1 to 11 , wherein the elevations ( 3 ) of the fiber layer material face the absorbent body. 13. hygiene article, in particular sanitary napkin, with an absorbent body ( 8 ) and a body-side cover layer ( 9 ), characterized in that between the cover layer ( 9 ) and the absorbent body ( 8 ) an intermediate layer (tissue layer 10, nonwoven layer 1 ') of fiber layer material after one of claims 1 to 11 is introduced, the elevations ( 3 ) being arranged at least on the surface ( 2 , 2 ′) of the intermediate layer (tissue layer 10, nonwoven layer 1 ′) facing the absorbent body ( 8 ) or cover layer ( 9 ).