DE102006000779A1 - Multilayer absorbing core for absorbing sanitary product, has first layer with front and rear side consisting of composition from super absorbing fabric, multi-component fabric and fabric on basis regenerated cellulose and polyester fabric - Google Patents

Abstract

Multilayer absorbing core, has a first layer with a front and rear side consisting of a composition from super absorbing fabric, multi-component fabric as well as a fabric on the basis regenerated cellulose and polyester fabric. The second layer has a front and rear side consisting of a composition made of multi-component fabric and super absorbing fabric. The front and rear side of first layer is adjacent to the rear and front side of the second layer. An independent claim is also included for absorbing sanitary products.

Description

The The present invention relates to a multilayer absorbent Core for an absorbent hygiene article and absorbent hygiene products, in particular absorbent hygiene products for feminine hygiene, comprising at least one absorbent according to the invention Core.

Of the Trend in sanitary napkins and panty liners is currently in Direction thinner and thinner Products. Of course is also very thin of these Hygiene products despite the lower material use a high Absorption and retention capacity required. moreover If you are generally unwilling to sacrifice comfort in purchasing to take. Even very thin Absorbing products are required to be on the skin feel very soft and at the same time are very flexible, even under heavy use the body shape to be able to adapt so that leakage can be prevented in any situation.

Special Meaning comes with sanitary napkins and panty liners the absorbent Core too. This determines significantly the thickness of the hygiene product as well as the absorption and retention behavior of the hygiene product absorbent product.

The EP 1 030 633 B1 deals with absorbent articles such as panty liners and sanitary napkins that adapt well to the body, reducing the risk of leakage. The absorbent article according to the EP 1 030 633 B1 is characterized by a bending resistance of not more than 100 g. The absorbent core is in this case composed of a so-called "high loft" material having a density of preferably less than 0.01 g / cm ^3. Preference is given, for example, to thermally bonded, kadierte polyester fiber webs having a basis weight of about 50 g / m ² In addition, wood pulp fibers, meltblown polymer fibers, regenerated cellulose fibers and superabsorbent materials are also suitable for the core EP 1 030 633 B1 recourse to mixtures of synthetic polymer fibers, cellulose fibers and fibers of a superabsorbent, hydrogel-forming polymer. The superabsorbent hydrogel-forming polymer may also be incorporated in particulate form into a so-called airlaid nonwoven. These airlaid nonwovens may be solidified by means of needlepunching, for example. As far as the EP 1 030 633 B1 discloses an absorbent core having a layered structure, this is the previously described airlaid nonwoven, which is underlaid with a layer of particles or fibers of a gel-forming polymer material. The absorbent article according to EP 1 030 633 B1 However, it still leaves nothing to be desired in terms of wearing comfort, softness and leakage protection, in particular in the case of absorbent hygiene articles which are designed in very thin form.

Of the The present invention was therefore based on the object, an absorbent Article accessible to do not suffer from the disadvantages of the state of the art and is characterized by a high degree of softness and flexibility at the same time very high absorption and retention capacity.

Accordingly, became a multi-layer absorbent core with a front and a front back for one absorbent hygiene article comprising at least one first layer with a front and a back, containing a mixture from superabsorbent fibers, multicomponent fibers and fibers based on regenerated cellulose and / or polyester fibers, and at least a second layer having a front and a back, containing a mixture of multicomponent fibers and superabsorbent Fibers, with the front or back the first shift to the return or front side of the second layer is adjacent.

According to one preferred embodiment, it is provided that the first layer 20 up to 45% by weight of fibers based on regenerated cellulose, 30 to 50 wt .-% multicomponent fibers and 5 to 50% by weight of superabsorbent fibers and / or that the second layer 40 to 80 wt .-% multicomponent fibers and 20 bis 60 wt .-% superabsorbent fibers.

A another embodiment of the invention provides at least two of the previously described multilayered ones to combine absorbent cores. Preferably, this is the respective outer surfaces of the second layer of the first core and the first layer of the second Kerns, for example, the back the second layer and the front of the first layer, at least in some areas or at least in large part, i. with a common overlap area of more than 50%, adjacent.

In has a further development the absorbent according to the invention Kern further about at least a third layer with a front and a back, containing a mixture of superabsorbent fibers, fibers based on regenerated cellulose and multicomponent fibers, at least partially between the first and second layers is appropriate.

in this connection is preferred that the first layer 20 to 45 wt .-% fibers on the Base of regenerated cellulose, 30 to 50% by weight of multicomponent fibers and 5 to 50% by weight of superabsorbent fibers and / or that the second layer 40 to 80 wt .-% multicomponent fibers and 20 bis 60 wt .-% superabsorbent fibers and / or that the third layer 10 to 60% by weight of regenerated cellulose fibers, 30 to 50 wt .-% multi-component fibers and 10 to 40 wt .-% superabsorbent Fibers include.

A another embodiment of the invention provides at least two of those described immediately above to combine multilayer absorbent cores. Preferably in this case lie the respective outer surfaces of the second layer of the first core and the first layer of the second core, for example the backside the second layer and the front of the first layer, at least in some areas or at least in large part, i. with a common overlap area of more than 50%, adjacent.

The Cores according to the invention are preferably flat designed with opposite Top and bottom sides. The peripheral edge areas can be a Accept variety of different cross-sectional geometries. The Thickness of the flat cores according to the invention can be varied within a wide range. Very thin cores, e.g. with a thickness in the range of about 1 to 5 mm, can be realized as well as thicker or very thick cores in the range of 5 to 20 mm, wherein with thick and in particular very thin cores according to the invention the advantageous properties sought with the present invention, like a very good absorption and retention capacity at the same time high flexibility, achieve. moreover in a further embodiment the plane Cores according to the invention a longitudinal axis and a smaller dimensioned, perpendicular thereto can be arranged transverse axis on. With the cores according to the invention are accordingly very thin products for the feminine hygiene such as sanitary napkins and pantyliner accessible, that barely apply on clothing, are comfortable to wear and at the same time a high fluid absorption capacity Offer. Likewise, with thicker products a very good Wearing comfort with good flexibility.

in this connection can be provided that the fibers regenerated on the basis Cellulose e.g. Modal, cupro, lyocell and in particular viscose fibers and / or that the polyester fibers are polyethylene terephthalate fibers and / or that the multicomponent or multicomponent fibers are bicomponent fibers, in particular polyethylene / polypropylene fibers.

Natural cellulose fibers are obtained, for example, from so-called wood fiber pulp. Their preparation and processing is well known to those skilled in the art. The same applies to regenerated cellulose fibers. Suitable regenerated cellulose also includes cellulose acetate fibers. Lyocell fibers are regenerated cellulose fibers which are particularly environmentally friendly to produce. These fibers are obtained by extrusion of an aqueous tertiary amine N-oxide, for example N-methymorpholine N-oxide, dissolved cellulose into an aqueous coagulation bath by the solvent spinning method. For further details regarding the production process of lyocell fibers, see US 5,094,690 directed. Lyocell fibers are more similar in their property profile to cotton fibers than rayon fibers. Lyocell fibers are characterized in particular by a high strength in the wet state. Lyocell fibers can be purchased, for example, from the companies Acordis Cellulosic Fiber under the trade name Tencel or the company Lenzing Fibers under the trade name Lenzing Lyocell.

Suitable multicomponent fibers include, for. B. bi- and tricomponent fibers. Under bicomponent fibers are generally understood to mean those fibers in which two different polymers in non-homogeneous form next to each other. This may mean in one embodiment that two polymers are arranged side by side in a fiber strand side by side. In a further embodiment, a first polymer may form the core which is enveloped by a second polymer. In addition, it is possible for a first polymer to be completely enveloped by a second polymer to form individual islands in the second polymer. Suitable bicomponent fibers are generally composed of two thermoplastic polymers, for example polyolefins and polyamides, polyolefins and polyesters or polyamides and polyesters. Particularly suitable for the present fiber webs z. B. bicomponent fibers based on polyolefins and polyesters, in particular comprising the combinations polyethylene / polyethylene terephthalate and polypropylene / polyethylene terephthalate. Furthermore, in a further embodiment It is contemplated that the bicomponent fiber comprises a polyethylene / polypropylene fiber, a polypropylene / polyethylene terephthalate fiber, a polyethylene polyethylene terephthalate fiber, a polyethylene terephthalate / co-polyethylene terephthalate fiber, or any mixture thereof. Bi-component fibers based on polyethylene and polypropylene are particularly preferred.

Especially further preferred are such absorbent cores in which the first, second and / or third layer using air-through bonding Technically produced layers include.

Also of advantage are those embodiments in which the first layer has a basis weight in the range from 10 to 90 g / m ² and / or the second layer has a basis weight in the range from 10 to 90 g / m ² and / or the third layer has a basis weight in the range of 10 to 90 g / m ² .

Especially preferred absorbent cores are characterized in that the Liquid Retention Capacity of Kerns at least twelve times Dry weight thereof.

Regarding the retention capacity are the absorbent according to the invention Cores preferably capable of applying pressure at least 20% by weight of absorbed total amount of liquid in the absorbent To keep the core.

In preferred embodiments has the absorbent core over a bending stiffness determined by the "circular bonding test" of not more than 100 g.

Very thin absorbent Cores are inventively also by accessible, that you have calendered these at least partially.

Also has proved to be advantageous, the fibers of the first, second and / or third layer of the absorbent core by carding to mix. Accordingly, the first, second and / or third layer at least in regions a carding available Fiber mixture.

According to one Another aspect of the present invention is absorbent hygiene products. especially absorbent products for feminine hygiene, such as Panty liners and sanitary napkins, provided, the at least one absorbent according to the invention Core include. These absorbent products feature in the Usually over at least one liquid-permeable cover layer and at least one liquid-impermeable barrier layer, between which at least one inventive absorbent core is provided is.

The Absorbent hygiene product accordingly comprises in a further development according to the invention at least two adjoining absorbent invention according to the invention Cores, with the front or back the first nucleus to the return or front side of the second core is adjacent.

The multilayered according to the invention absorbent cores are distinguished over comparable systems by a good absorption capacity and an increased retention capacity, in particular under pressure, out. This applies in particular to Systems with higher Basis weights. In addition, a considerably increased flexibility with the structures according to the invention achieved. The absorbent according to the invention Cores stand out above all compared to comparable, means Airlaid technology manufactured systems.

• ¹⁾ bei der Viskosefaser handelt es sich um Lenzing-Viskosefasern der Firma Lenzing, bei der Bikomponentenfaser (Bico) handelt es sich um die Faser ES-Cure der Firma FiberVisions, bei der superabsorbierenden Faser (SAF) handelt es sich um die Faser „Super absorbent fiber 102" der Firma OASIS.
• ²⁾ Die Fasern der ersten und zweiten Schicht gemäß Beispiel I sowie der ersten, zweiten und dritten Schicht gemäß Beispiel III wurden jeweils unter Einsatz der Kardiertech nik homogen vermischt. Die einzelnen Lagen wurden mittels Air-through-bonding Technik verfestigt, und der Mehrschichtlagenverbund mittels Kalandrierens erhalten. In gleicher Weise wurden die Doppelstrukturen der absorbierenden Kerne gemäß den Beispielen II und IV dadurch erhalten, dass man die Mehrschichtsysteme gemäß Beispiel I bzw. III übereinandergelegt und mittels Kalandrierens miteinander verbunden hat.

The advantages and properties of the absorbent core according to the invention are explained in more detail below by means of examples. The Examples II and IV according to the invention listed below can essentially be obtained by superimposing two absorbent multilayer structures according to Example I or according to Example III on top of each other to form an absorbent multilayer core and bonding them together. The composition of the absorbent cores according to the invention is shown in Table 1 below. Table 1

• ¹⁾ the viscose fiber is Lenzing viscose fibers from Lenzing, the bicomponent fiber (Bico) is the fiber ES-Cure from FiberVisions, the superabsorbent fiber (SAF) is the fiber "Super absorbent fiber 102 "from OASIS.
• ²⁾ The fibers of the first and second layer according to Example I and the first, second and third layer according to Example III were each mixed homogeneously using the Kardiertch technology. The individual layers were consolidated by means of air-through-bonding technique, and obtained the multilayer composite by means of calendering. In the same way, the double structures of the absorbent cores according to Examples II and IV were obtained by overlaying and bonding the multilayer systems according to Examples I and III, respectively, by means of calendering.

In Table 2 below shows the absorption and retention behavior the absorption layer structures according to the invention and contrasted with an absorbent core according to the prior art.

• ³⁾ Die absorbierenden Mehrschichtkerne wurden für zwei Minuten mit Wasser getränkt und anschließend für 10 Minuten auf ein horizontal angeordnetes Abtropfgitter aufgelegt.
• ⁴⁾ Bei der absorbierenden Vergleichsstruktur handelt es sich um die kommerziell erhältliche Struktur Concert MH 102 (80 g/m²).

Table 2

• ³⁾ The multi-layered absorbent cores were soaked in water for two minutes and then placed on a horizontally arranged drip grid for 10 minutes.
• ⁴⁾ The comparative absorbent structure is the commercially available structure Concert MH 102 (80 g / m ² ).

As the preceding examples show, the multilayer inventive absorbent cores by a very advantageous absorption capacity, although they are opposite usual absorbent core structures over a much lower basis weight feature. Without being bound by any theory, it is presently believed that the absorbent according to the invention Structures do not show any flow path blockages due to gel formation.

From Another particular advantage is that the advantageous properties the absorbent of the invention Cores also in terms of absorption and retention capacity with very flexible structures. For example, the absorbent cores according to the examples I and II about one Bend resistance according to the Circular Bending test of about 8 or 10 g. On the other hand, the absorbent Core according to the comparative example a bending resistance according to the Circular Bending test of about 60 g.

The Circular Bending Test is generally performed with an Instron 4411, Series IX, with a 6.35 mm diameter plunger and a spherical attachment with a needle point 0.8 mm in diameter. The ram has a travel distance of 16.35 mm and is moved up and down at a speed of 500 mm / min. The layer structures to be examined had a size of 38 × 38 mm ² and were conditioned for 24 hours at 20 ° C. ± 2 ° C. and 65% ± 2% atmospheric humidity before the start of the test. The test specimens were positioned over the opening of a polished metal plate whose circular opening had a diameter of 18.75 mm at the bottom of the plate and 28.25 mm at the top. The edge of this circular opening was inclined by 45 °. Maximum flexural stiffness was measured while the plunger deflected the 6.35 mm test product downwards. The reproduced values represent the arithmetic mean of a total of ten individual measurements.

The in the above description and in the claims Features of the invention can both individually and in any combination for the realization be essential to the invention in its various embodiments.

Claims (16)

Multilayer absorbent core with a Front and one back for one absorbent sanitary article comprising at least a first layer with a front and a back, containing a mixture of superabsorbent fibers, multicomponent fibers and fibers based on regenerated cellulose and / or polyester fibers, and at least a second layer having a front and a back, containing a mixture of multicomponent fibers and superabsorbent Fibers, with the front or back the first shift to the return or front side of the second layer is adjacent. Absorbent core according to claim 1, characterized in that that the first layer regenerated 20 to 45% by weight of fibers on the basis Cellulose, 30 to 50 wt .-% multicomponent fibers and 5 to 50 wt .-% superabsorbent Fibers and / or that the second layer 40 to 80 wt .-% multi-component fibers and 20 to 60 wt.% of superabsorbent fibers. Absorbent core according to claim 1 or 2, further comprising at least a third layer with a front and a Back, containing a mixture of superabsorbent fibers, fibers based on regenerated cellulose and multicomponent fibers, at least partially between the first and second layers is appropriate. Absorbent core according to claim 3, characterized that the first layer regenerated 20 to 45% by weight of fibers on the basis Cellulose, 30 to 50 wt .-% multicomponent fibers and 5 to 50 wt .-% superabsorbent Fibers and / or that the second layer 40 to 80 wt .-% multi-component fibers and 20 to 60% by weight of superabsorbent fibers and / or that the third layer 10 to 60 wt .-% fibers based on regenerated Cellulose, 30 to 50 wt .-% multicomponent fibers and 10 to 40 Wt .-% superabsorbent fibers. Absorbent core according to one of the preceding Claims, characterized in that the fibers are regenerated on the base Cellulose modal, cupro, lyocell and in particular viscose fibers and / or that the polyester fibers polyethylene terephthalate fibers and / or that the multicomponent fibers bicomponent fibers, in particular Polyethylene / polypropylene fibers. Absorbent core according to one of the preceding Claims, characterized in that the first, second and / or third layer comprising layers produced using the air-throughbonding technique. Absorbent core according to one of the preceding claims, characterized in that the first layer has a basis weight in the range of 10 to 90 g / m ² and / or the second layer has a basis weight in the range of 10 to 90 g / m ² and / or the third Layer a basis weight in the range of 10 to 90 g / m ² include. Absorbent core according to one of the preceding Claims, characterized in that the liquid retention capacity of the Kerns at least twelve times Dry weight of the same includes. Absorbent core according to one of the preceding Claims, characterized in that when applying pressure at least 20% by weight of absorbed total amount of liquid in the absorbent Core remain. Absorbent core according to one of the preceding Claims, characterized by a bending stiffness, determined according to the "circular bonding test ", from not more than 100 g. Absorbent core according to one of the preceding Claims, characterized in that this at least one calendered Area includes. Absorbent core according to one of the preceding Claims, characterized in that the first, second and / or third layer at least in some areas available by carding Fiber mixture includes. Absorbent hygiene product, in particular absorbent Product for the feminine hygiene, comprising at least one absorbent Core according to one of the preceding claims. Absorbent product according to claim 13, characterized by at least two abutting absorbent cores according to one the claims 1 to 12, with the front or back of the first core too the return or front side of the second core is adjacent. Absorbent product according to claim 13 or 14, comprising a sanitary napkin or a panty liner. Absorbent product according to one of Claims 13 to 15, comprising at least one liquid-permeable covering layer, at least one absorbent core according to one of Claims 1 to 12, and at least one liquid impermeable barrier layer.