WO2004113608A2

WO2004113608A2 - Airlaid method with an improved through-put rate

Info

Publication number: WO2004113608A2
Application number: PCT/EP2004/006441
Authority: WO
Inventors: Alexander SCHMIDT-FÖRST; Franz Aschenbrenner
Original assignee: Hakle-Kimberly Deutschland Gmbh
Priority date: 2003-06-16
Filing date: 2004-06-15
Publication date: 2004-12-29
Also published as: EP1633923A2; AU2004249862B2; CA2528421A1; US20070266503A1; ZA200509720B; DE10327026A1; JP2007526950A; KR20060025553A; JP4792391B2; AU2004249862A1; BRPI0411471A; AR044784A1; WO2004113608A3; MXPA05013207A; DE10327026B4; KR101121362B1

Abstract

The invention relates to a method for the production of a non-woven fibre according to an aerodynamic method, having an improved through-put rate. The invention also relates to a non-woven fibre produced according to said method, and to a short fibre which is suitable for use in said method.

Description

Airlaid process with improved throughput

description

The present invention relates to a process for producing a nonwoven fabric by an areodynamic process (hereinafter "airlaid process"), a nonwoven fabric produced by the process, and a short fiber suitable for use in the process.

The education . of nonwoven fabrics by airlaid processes is known in the art. These ^'are dry processes in which the fibers are passed after the process of opening a stream of air and are then deposited on a screen surface.

In the past, airlaid processes have mainly used cellulose fibers which can contain small amounts of other fibers, such as viscose fibers. There is a problem with the use in particular of viscose fibers in higher proportions. in that in conventional airlaid systems. throughput to be achieved is considerably lower than when using pulp fibers alone. Throughput means the weight of fibers delivered to the transport air stream in one unit of time. This also leads to large deviations in the target basis weight, and thus to a low quality of the resulting nonwovens.

The applicants of the present application have found in test trials that only the use of commercially available short viscose fibers in an airlaid process results in a throughput which is generally less than 10 percent of the throughput of cellulose fibers.

There is thus a need for airlaid process in which an increased throughput can be achieved with higher proportions of viscose fibers and thus the capacity of the ^'production can be better utilized. The applicants of the present invention have surprisingly found that by providing viscose short fibers with a finish, the throughput in an airlaid process can be increased considerably. The improvement achieved is of a magnitude which even exceeds the throughput in the conventional use of cellulose fibers, so that it is assumed that the method according to the invention is generally applicable, regardless of the particular fiber.

Providing fibers with a finish is known in principle in technology and chamfers with a finish are used, for example, in carding processes. However, this is a fundamentally different process that also uses longer fibers. According to the current state of knowledge of the applicants, there has so far been no reason for airlaid processes to provide fibers with a finish.

The invention is described in detail below with reference to the accompanying drawings, in which:

Figure 1 is a graph showing the dependence of the throughput on the humidity, and

Figure 2 is a graph showing the dependence of the throughput on the finish quantity.

The present invention thus relates to a process for producing a nonwoven fabric, comprising the laying down of at least one layer comprising short fibers by an airlaid process, at least some of the short fibers having a finish in an amount of greater than 0.035% by weight, based on the fiber weight the finish-containing short fibers.

In the present application, a fiber fleece is understood to mean a layer of fibers which comprises short fibers, the fibers not being arranged regularly. Short fibers are defined herein as fibers with a length in the range of 2 to 12 mm. The term short fibers as used herein denotes all short fibers used in the process, to the exclusion any binding short fibers and superabsorbent short fibers that may be present. A "layer comprising short fibers" is understood here to mean a layer in which the fibers which essentially form the layer are short fibers, but additional materials, such as binding materials, superabsorbents, etc. , may be in the form of longer fibers or in a form other than fibers. If binder materials and / or superabsorbents are present and are not in the form of short fibers, the short fibers generally make up more than 50% by weight, typically more than 60% by weight, of the layer. Short fibers plus short bond fibers and / or superabsorbent short fibers generally make up more than 90% by weight, typically more than 95% by weight of the layer.

According to the invention, at least some of the short fibers are provided with the finish. In general, at least 5% by weight of the short fibers are provided with the finish, preferably at least 10% by weight, such as at least 25% by weight, for example at least 50% by weight. As an example of the use of fiber mixtures e.g. preferably more than 25%, in particular more than 50%, for example all of the short fibers whose throughput is problematic, such as viscose fibers, provided with the finish, while the short fibers which can be used without problems have no finish. Alternatively, essentially all of the short fibers used in the airlaid process can be provided with the finish.

In a special embodiment of the method according to the invention, a binding material is also deposited in addition to the short fibers. Binder material is generally understood here to mean materials which, owing to their dissolving or melting properties, can cause the short fibers to bond to one another. The binders have any shape as long as this is compatible with the use in an airlaid process, for example powder, etc. However, the binder materials are preferably also short fibers, i.e. Binding short fibers.

Examples of fibers which can be used as binder fibers because of their solvent properties, are polyvinyl alcohol fibers (PVA fibers) and ^'alginate fibers. Fibers because of their Thermal properties that are suitable as binding fibers are generally hot-melt adhesives or fibers comprising a thermoplastic material that has a lower softening temperature than the fibers to be bound. Melt binding fibers can be used as full profile fibers or multi-component fibers. A preferred melt binding fiber is a two-component fiber (BIKO fiber), for example a two-component fiber with a fiber jacket made of a polymer, which has a lower melting point than the polymer of the fiber core. An example of this is a two-component fiber, comprising a polyester core and a polyethylene jacket.

The term "short binding fibers" as used herein denotes fibers with a length in the range of 2-12 mm, preferably of 4-8 mm. The short binding fibers generally have a length-to-weight ratio of 1.0 to 6.0 dtex, preferably 2.0 to 4.0 dtex, for example approximately 3.0 dtex.

The binder is used in an amount that is ultimately dictated by the desired properties of the final product. Parameters that thus influence the amount of binder are therefore both the type of binder and the type of fibers or fiber mixture to be bonded, as well as the intended strength, softness / rigidity and weight per unit area of the end product, etc. In general, the amount is of binder 1-30 wt .-%, based on the total weight of the short fibers to be bound and the binder, in particular 1-20 wt .-%, such as 3-10 wt .-%, for example 5-8 wt .-%.

The inventors have also found that the moisture of the short asers used in the airlaid process has an impact on throughput. Accordingly, the short fibers preferably have a moisture content in the range of 4-16%, in particular 6-14%, for example 8-12%. Moisture is measured according to the method described below.

Short fibers which are suitable for use in the method according to the invention essentially comprise all fiber types known in the art, ie natural fibers, cellulosic chemical fibers, synthetic fibers and inorganic fibers and combinations from that. Examples of natural fibers include natural vegetable fibers, such as fibers made from cellulose, cotton, jute, flax, hemp and coconut, and natural animal fibers, such as wool and silk. Cellulosic chemical fibers include regenerated cellulose fibers, such as viscose fibers, cupro fibers and lyocell fibers. Synthetic fibers include, for example, polyolefin fibers, polyester fibers and polyamide fibers, and inorganic fibers include glass fibers, silicate fibers, carbon fibers, boron fibers and metal fibers.

Preferred types of fibers for use in the method according to the invention are natural fibers, in particular vegetable natural fibers and cellulosic chemical fibers, in particular cellulose fibers, cotton fibers, viscose fibers and lyocell fibers.

As mentioned at the outset, the method of the present invention was originally developed with a view to using a high proportion of viscose fibers. According to a particular embodiment, the short fibers thus comprise short viscose fibers, at least some of the short viscose fibers being provided with the finish. Preferably at least 20%, more preferably at least 50%, of the short viscose fibers are provided with the finish. For example, the entire short viscose fibers are finished.

The viscose short fibers advantageously have a multi-section, such as a three-section. Such fibers are known in the art, see e.g. U.S. Patent No. 5,643,914, the contents of which are incorporated by reference in their entirety. Three-section cross-section fibers are e.g. can be seen from Figures 1-5 of this document.

According to this embodiment, the viscose fibers are usually present in an amount of greater than 85% by weight, based on the total weight of the short fibers, in particular in an amount of greater than 90% by weight, such as greater than 95% by weight. used. For example, only viscose short fibers, ie 100% by weight, are used as the short fibers. The short fibers are by definition in the range of 2-12 mm, and preferably in the range of 4-8 mm, such as 5-6 mm. In general, the short fibers have a length to weight ratio of 1.0 to 6.0 dtex, preferably 2.0 to 4.0 dtex, for example about 3.3 dtex.

If necessary, a superabsorbent material is also deposited in the method according to the invention. Superabsorbers (SAP) are well known in the art and are therefore not discussed in detail here. SAPs usually consist of polymers based on acrylates and are characterized in that they can absorb several times their own weight in liquid. The superabsorbent materials are used in the process according to the invention in any suitable form which is compatible with the airlaid process, for example in the form of granules, preferably in the form of fibers, in particular short fibers with a length in the range from 2-12 mm, in particular from 4- 8 mm. If used, the amount of superabsorbent material is generally 0.1-50% by weight, in particular 5-10% by weight, based on the weight of the short fibers (excluding any binding short fibers that may be present).

The finish is present in an amount greater than 0.035% by weight, based on the weight of the short fibers provided with the finish. In this description, finish quantity is understood to mean the amount actually present on the fiber according to the information of the fiber manufacturer.

The quantity values mentioned in this description thus relate to analysis values of the fiber manufacturer (Acordis), as determined by Soxleth extraction, derivalization (methylation) of the sample, gas-atographic separation and detection by means of a flame ionization detector.

Based on viscose fibers, the amount of finish is preferably greater than 0.05% by weight, more preferably greater than 0.10% by weight, most preferably greater than 0.15% by weight. The upper limit of the finish quantity is the quantity at which a further increase in the throughput, for example due to other limiting process parameters, no longer makes sense, the throughput is already almost optimal and further costs for more finish do not seem justified, or the high amount of finish leads to or contributes to undesirable product properties. The maximum amount is therefore dependent on the airlaid system used, the short fibers or short fiber mixtures used as well as on the end product and its desired properties.

Based on viscose fibers, it is currently assumed that the maximum amount of finish, based on the weight of the short fibers provided with the finish, is 1% by weight, in particular 0.75% by weight, for example 0.50% by weight. Analog finish quantities are assumed for other types of fibers.

Any material is suitable as a finish which, if present on the surface of the short fiber in the specified quantity range, is suitable for improving the throughput of the airlaid process according to the invention. The finish is preferably selected from:

(a) Ester and ether derivatives of polyethylene oxide and polypropylene oxide of the general formula:

Rl- (CO) _o -0- [-CH ₂ - (CH ₂ ) _m -0-] _n - (CO) _p -Rl

wherein R1 is independently a saturated or unsaturated hydrocarbon radical with 12-22, in particular 14-20 carbons, which may optionally have one or more free hydroxyl groups, o and p are independently 0 or 1, m is 0 or Is 1 and n is 1-15, preferably 3-11, in particular 4-7,

(b) mono-, di- and triesters of sorbitans with fatty acids of the formula Rl-COOH, wherein Rl is independently defined as above for each occurrence,

(c) mono-, di- and triglycerides of fatty acids of the formula Rl-COOH, wherein Rl is independently as defined above for each occurrence,

(d) imidazolium ethosulfates and methosulfates, (e) ethoxylated and propoxylated derivatives of the compounds according to (a), (b), (c) and (d), and

(f) Mixtures of compounds according to (a), (b), (c), (d) or / and (e).

The imidazolium ethosulfates or methosulfates generally have a structure according to the general formula (I) below

(I)

where R2 is H or a C1-C6 alkyl radical, R3 independently of each other is a saturated or unsaturated hydrocarbon radical with 6-22 carbon atoms, which may optionally have one or more free hydroxyl groups, R4 is methyl or ethyl, r is 2, 3 or 4, and s is 0 or 1.

Preferred imdiazolium derivatives of the formula (I) according to a first embodiment are imidazolium methosulfates (R4 = methyl), where R2 is methyl or ethyl, more preferably methyl, R3 is independently a hydrocarbon radical with 14-18 carbon atoms in each occurrence, r is 2 and s equal to 1 is. According to a second preferred embodiment, R2 and R3 are defined as in the first preferred embodiment, and s is 0. According to a further preferred embodiment, R2 is methyl or ethyl, more preferably methyl, R3 is independently a hydrocarbon residue with 6-12 in each occurrence Carbon atoms, r is 2 and s is 1. According to yet another special embodiment, R3 is an alkyl radical.

Examples of ethylene oxide derivatives are the diesters of lauric acid, palmitic acid, oleic acid and / or stearic acid with polyethylene glycol with an average molecular weight of, for example, 400 or 600. Examples of sorbitan esters are ethoxylated derivatives of sorbitan monoesters, diesters and triesters with lauric acid, palmitic acid, oleic acid and / or stearic acid. An example of the glyceride derivatives is hydrogenated, ethoxylated castor oil, and examples of the imidazolium derivatives are Rewoguat ® W75 and Rewoquat ® W90 from Degussa.

The improvement in throughput through the use of short fibers, at least part of which is finished, is preferably at least 20%, more preferably at least 50% and most preferably at least 100%, compared to the same short fibers, but without that Finish.

The invention. The method is optionally combined with further steps to form a fiber layer, in particular a nonwoven fabric. Accordingly, the method according to the invention can be carried out in such a way that the layer which forms is deposited on a previously formed fiber layer. The previously formed fiber layer can be, for example, a layer formed by an airlaid process, or a layer formed by another process, for example a spunbond or meltblown layer, or a combination of such layers.

Furthermore, the method according to the invention can include the deposition of several layers, for example the deposition of two or three layers, optionally in combination with one or more other layers, as explained above. One or more other layers, as explained above, can be deposited on the (uppermost) layer according to the invention.

Following the formation of the nonwoven fabric according to the invention, this can be subjected to further process steps. Such steps include, for example, heat treatment, especially if thermoplastic binder fibers were used. In this case, the heat treatment comprises heating the nonwoven fabric to a temperature above the softening temperature of the binding fiber or the lowest melting component of the binding fiber, for a sufficient period of time to at least partially melt the fiber or component to reach. Other optional process steps include compacting, embossing, printing, etc.

Another object of the present invention is a nonwoven fabric produced by the method according to the invention. Accordingly, the present invention also provides a nonwoven fabric comprising at least one layer comprising short fibers, at least some of the short fibers having a finish in an amount of greater than 0.035% by weight, based on the fiber weight of the finish-containing short fibers.

According to a particular embodiment, the layer comprises short fibers in an amount of 70-99% by weight and binding material in an amount of 1-30% by weight, based on the total weight of short fibers and binding material.

The binding material is as explained above in relation to the method according to the invention, and preferably comprises short binding fibers, in particular multicomponent fibers, such as, for example, two-component fibers, comprising a polyester core and a polyethylene jacket. Short binding fibers generally have a length-to-weight ratio of 1.0 to 6.0 dtex, preferably 2.0 to 4.0 dtex.

The short fibers are as explained above in relation to the method according to the invention, and preferably comprise natural fibers, in particular vegetable natural fibers and cellulosic chemical fibers, in particular cellulose fibers, cotton fibers, viscose fibers and lyocell fibers.

According to a special embodiment, the layer of the nonwoven fabric according to the invention comprises short viscose fibers, at least some of which are provided with the finish. Preferably at least 20%, more preferably at least 50%, of the short viscose fibers are provided with the finish. For example, the entire short viscose fibers are finished. The viscose short fibers advantageously have a multi-section, such as a three-section. According to this embodiment, the viscose fibers are usually present in an amount of more than 85% by weight, based on the total weight of the short fibers, in particular in an amount of more than 90% by weight, such as more than 95% by weight. For example, the short fibers are exclusively viscose short fibers.

The short fibers are by definition in the range of 2-12 mm, and preferably in the range of 4-8 mm, such as 5-6 mm. In general, the short fibers have a length to weight ratio of 1.0 to 6.0 dtex, preferably 2.0 to 4.0 dtex, for example about 3.3 dtex.

The layer optionally comprises a superabsorbent material (SAP), preferably in the form of fibers, in particular short fibers, with a length in the range of 2-12 mm, in particular 4-8 mm. If used, the amount of superabsorbent material is generally 0.1-50% by weight, in particular 5-10% by weight, based on the weight of the short fibers.

As explained above in connection with the method according to the invention, the finish is in an amount of greater than 0.035% by weight, preferably greater than 0.05% by weight, more preferably greater than 0.10% by weight, most preferably greater than 0 , 15% by weight, and at most in an amount of 1% by weight, in particular 0.75% by weight, for example 0.50% by weight. These quantities refer to the weight of the short fibers provided with the finish.

The finish is as discussed above in connection with the method according to the invention.

The nonwoven fabric according to the invention optionally comprises several layers according to the invention and / or other layers, as explained above.

The layer comprising short fibers of the nonwoven fabric according to the invention generally has a basis weight of 50-350 g / m2, typically 75-250 g / m 2, in particular 150-220 g / m2. such as about 180 g / m2. The density of the layer is generally from 0.02-0.5 g / cm3, typically from 0.03-0.2 g / cm3, in particular from 0.04-0.1 g / cm3. The above values relate to the material web as deposited in the airlaid process, before carrying out compacting process steps, such as calendering or embossing. The density is determined according to standard methods, under a load of 0.2 kPa.

The short fiber layer of the nonwoven fabric according to the invention generally has an absorbency of at least 3 g / g nonwoven fabric, preferably at least 4 g / g, particularly preferably at least 4.8 g / g. The absorbency is measured according to the well-known Syngina-Test ("Syn- gina Absorbancy Test") and in the absence of superabsorbent materials.

Yet another object of the present invention is a short fiber which is provided with a finish in an amount greater than 0.035% by weight, based on the weight of the fiber.

According to one embodiment, the short fiber is a chemical cellulose fiber or a synthetic fiber.

According to a preferred embodiment, the short fiber is a viscose fiber, which may have a multi-section, such as a three-section.

The short fiber has a length in the range of 2-12 mm, and preferably a length in the range of 4-8 mm, such as 5-6 mm. In general, the short fiber has a length-to-weight ratio of 1.0 to 6.0 dtex, preferably 2.0 to 4.0 dtex, for example approximately 3.3 dtex.

The finish is present in an amount greater than 0.035 weight percent, preferably greater than 0.05 weight percent, more preferably greater than 0.10 weight percent, most preferably greater than 0.15 weight percent, and at most in an amount of 1% by weight, in particular 0.75% by weight, for example 0.50% by weight. Suitable finish materials are those explained above in connection with the method according to the invention.

Yet another object of the present invention is the use of a short fiber as described above in an airlaid process.

Yet another object of the present invention is an absorbent object comprising a nonwoven fabric produced by the method according to the invention, or a nonwoven fabric as described above. The absorbent article has an absorbency of at least 3 g / g nonwoven, preferably at least 4 g / g, particularly preferably at least 4.8 g / g, as measured by the Syngina test.

The absorbent article is, for example, a personal hygiene article, such as a tampon, a sanitary napkin, a diaper or an incontinence article, or a household article, industrial article or medical article.

According to a particularly preferred embodiment, the absorbent object according to the invention is a tampon which comprises a spiral winding of a layer comprising short fibers according to the invention. The layer comprises 60-100% by weight three-part viscose short fiber and 0-40% by weight short cellulose fiber, based on the total weight of the short fibers. The short cellulose fiber and the short viscose fiber have a length of 4-8 mm, preferably about 6 mm and a length-to-weight ratio of 3-4 dtex. The layer further comprises 5-15% by weight of a BIKO short fiber, based on the total weight of short fibers and short fibers. The tampon has an absorption capacity of at least 4 g / g under load, a rigidity of at least 20N and an expansion capacity of at least 150%.

The invention is further described in the example below. The example is for the purpose of illustration only and should not be interpreted as limiting in any way.

MEASURING METHOD DETERMINATION OF FIBER MOISTURE

1. Water vapor-tight containers are weighed with an accuracy of ± 0.005 g at room temperature and the temperature at which the fiber samples are weighed after oven drying, and the values T ^> p (tare weight at room temperature) and TJJ (tare weight hot) are noted. It must be ensured that the determination of GH is carried out with the lid open.

2. A fiber sample (approx. 5 g) is placed in the container, the container is closed with the lid in a water vapor-tight manner and weighed with an accuracy of ± 0.005 g. The value GRT (weight at room temperature) is noted.

3. The lid of the container is removed and the container and lid are placed in a hot air oven at a temperature of 105 ± 3 ° C.

4. Drying is carried out for at least three hours, for example overnight. The oven must not be opened during the drying period.

5. The containers are sealed in a water vapor-tight manner with the lids in the oven. The sealed container is weighed at the same temperature at which the GJJ was measured. The value is noted as GJJ (hot weight).

6. Calculation:

% Moisture = x 100

EXAMPLE

After preliminary tests, in which it was found to be influenced by a finish present on the fibers and to a lesser extent by the moisture of the fibers, fibers with the specification given in Table 1 were produced. The short Length-to-weight ratio of 3.3 dtex and a length of 5 mm, obtained by dry cutting using a guillotine process. The finish used was polyglycol palate stearate ester.

The fibers were then used to produce airlaid nonwovens using a Danweb airlaid system with 4 laying heads and a laying width of 600 mm. The system is suitable for multibonding as well as for the production of latex-bound and thermally bound products. The bore diameter of the laying heads was 4.5 mm.

The fibers of samples 1-5 were combined with a binding fiber Trevira T255 (PΞT / PE) with a length-to-weight ratio of 3.0 dtex and a length of 6 mm, in a weight ratio of rayon fiber : 93: 7 binding fiber used. The ambient conditions were 23 ° C and 73% relative air humidity, the target weight per unit area was 180-220 g / m.2, with a density of 0.04 g / cm3.

In order to determine the maximum throughput of the airlaid system, the maximum amount of fibers that are transported through the laying heads without blocking them is determined. In addition, the basis weight must remain stable, with a maximum deviation of ± 10% from the target value both in the machine direction and in the transverse direction. The maximum capacity is the maximum fiber quantity supplied to the laying heads per unit of time, measured on the fiber metering device.

The test was carried out successively with samples 1-5, the moisture and / or finish values being increased from test to test so as to avoid contamination of the system by fibers with a higher moisture content or amount of finish.

In each experiment the fiber feed was increased to the point where fiber accumulation occurred in the laying heads. The last stable setting is the maximum throughput in the airlaid system. The airlaid system used two out of four Put heads. The results of the tests are summarized in Table 1.

Table 1

Moisture: measured using the method described herein

Finish type: polyglycol palmitate stearate ester

Maximum throughput: stated in kg / h per 2 laying heads

The results are shown graphically in FIGS. 1 and 2. The results show in particular:

1. A higher amount of finish and higher moisture increase the throughput of viscose fibers on the airlaid system.

2. An increase in moisture from 4.1% to 8.7% with a comparable finish quantity increases the throughput from 120.5 to 154.0 kg (+ 28%) (FIG. 1).

3. Increasing the amount of finish from 0.052 to 0.085 and further to 0.16, with comparable humidity, increases the throughput from 154 to 170.1 kg (+ 10%) or to 222.6 kg (+ 45%) ( Fig. 2).

4. The highest throughput was obtained with 9.3% moisture and 0.16% finish. The graphic evaluation in FIGS. 1 and 2 indicates that a further increase in the throughput can be expected if the moisture and / or the finish increase further. 5. The throughputs achieved in these tests exceeded all previous results with synthetic fibers on the airlaid system used.

6. It is assumed that the throughputs achieved in these tests also exceed the maximum throughputs of 100% pulp. For the heads used with 4.5 mm holes, there is still no reliable data available; for laying heads with 4.0 mm holes, the maximum values for 100% are around 80 kg / h per laying head, i.e. 160 kg / h per two laying heads.

Claims

claims

1. A process for producing a nonwoven fabric, comprising the laying down of at least one layer comprising short fibers by an airlaid process, at least some of the short fibers having a finish in an amount of greater than 0.035% by weight, based on the fiber weight of the short fibers containing the finish, is provided.

2. The method of claim 1, wherein the layer comprises short fibers in an amount of 70-99 wt .-% and binding material in an amount of 1-30 wt .-%, based on the total weight of short fibers and binding material.

3. The method of claim 2, wherein the binding material comprises short binding fibers.

4. The method according to claim 3, wherein the binding short fibers are multicomponent fibers.

5. The method of claim 4, wherein the binding short fibers are bicomponent fibers comprising a polyester core and a polyethylene sheath.

6. The method according to any one of claims 2 to 5, wherein the binding short fibers have a length to weight ratio of 1.0 to 6.0 dtex.

7. The method according to any one of the preceding claims, wherein the short fibers have a moisture in the range of 4 to 16%.

8. The method according to any one of the preceding claims, wherein the short fibers comprise cellulose short fibers, cotton short fibers, cellulosic chemical short fibers, synthetic short fibers or a combination thereof.

9. The method of claim 8, wherein the short fibers comprise short viscose fibers and at least a portion of the short viscose fibers is provided with the finish.

10. The method according to claim 9, wherein at least some of the viscose short fibers have a multi-section cross-section.

11. The method of claim 10, the multi-section is a three-section.

12. The method according to any one of claims 9 to 11, wherein the short fibers comprise the viscose fibers in an amount of greater than 85 wt .-%, based on the total weight of the short fibers.

13. The method according to any one of the preceding claims, wherein the short fibers have a length in the range of 4-8 mm.

14. The method according to any one of the preceding claims, wherein the short fibers have a length to weight ratio of 1.0 to 6.0 dtex.

15. The method according to any one of the preceding claims, wherein the layer further comprises superabsorbent material.

16. The method according to any one of the preceding claims, wherein the finish is selected from

Rl- (C0) _o -0- [-CH ₂ - (CH) _m -0-] _n - (CO) p-Rl

(b) mono-, di- and triesters of sorbitans with fatty acids of the formula Rl-COOH, wherein Rl is independently defined as above for each occurrence, (c) mono-, di- and triglycerides of fatty acids of the formula Rl-COOH, in which Rl is independently as defined above for each occurrence,

(d) imidazolium ethosulfates and methosulfates,

(e) ethoxylated and propoxylated derivatives of the compounds according to (a), (b), (c) and (d), and

(f) Mixtures of compounds according to (a), (b), (c), (d) or / and (e).

17. The method according to any one of the preceding claims, wherein the layer comprising at least one short fibers is deposited on a fiber layer.

18. The method according to claim 17, wherein the fiber layer is a layer comprising short fibers, which has been deposited by an airlaid process.

19. The method according to any one of the preceding claims, comprising the deposition of layers comprising two or three short fibers.

20. Nonwoven fabric comprising at least one layer comprising short fibers, at least some of the short fibers having a finish in an amount of greater than 0.035% by weight, based on the fiber weight of the finish-containing short fibers.

21. The nonwoven fabric according to claim 20, wherein the layer comprises short fibers in an amount of 70-99% by weight and binding material in an amount of 1-30% by weight, based on the total weight of short fibers and binding material.

22. The nonwoven fabric according to claim 21, wherein the binding material comprises short binding fibers.

23. The nonwoven fabric according to claim 22, wherein the binding short fibers are multi-component fibers.

24. The nonwoven fabric according to claim 23, wherein the binding short fibers are two-component fibers comprising a polyester core and a polyethylene sheath.

25. The nonwoven fabric according to any one of claims 22 to 24, wherein the short binding fibers have a length-to-weight ratio of 1.0 to 6.0 dtex.

26. The nonwoven fabric according to one of claims 20 to 25, wherein the short fibers comprise cellulose short fibers, cotton short fibers, cellulosic chemical short fibers, synthetic short fibers or a combination thereof.

27. The nonwoven fabric according to claim 26, wherein the short fibers comprise short viscose fibers and the viscose fibers are provided with the finish.

28. The nonwoven fabric according to claim 27, wherein at least some of the short viscose fibers have a multi-section cross-section.

29. The nonwoven fabric according to claim 28, wherein the multi-section cross-section is a three-section cross-section.

30. Nonwoven fabric according to one of claims 27 to 29, wherein the short fibers comprise the viscose fibers in an amount greater than 85% by weight, based on the total weight of the short fibers.

31. Nonwoven fabric according to one of claims 20 to 30, wherein the short fibers have a length in the range of 4-8 mm.

32. Nonwoven fabric according to one of claims 20 to 31, wherein the short fibers have a length-to-weight ratio of 1.0 to 6.0 dtex.

33. Nonwoven fabric according to one of claims 20 to 32, wherein the layer further comprises superabsorbent material.

34. Nonwoven fabric according to one of claims 20 to 33, wherein the finish is selected from

Rl- (C0) _o -0- [-CH ₂ - (CH ₂ ) _m -0-] _n - (CO) p-Rl

(c) mono-, di- and triglycerides of fatty acids of the formula Rl-COOH, in which Rl is independently as defined above for each occurrence,

(d) Imidazolium ethosulfates and methosulfates

(f) Mixtures of compounds according to (a), (b), (c), (d) or / and (e).

35. Multi-layer nonwoven fabric, comprising at least one layer of a nonwoven fabric according to one of claims 20 to 34.

36. Short fiber with a finish in an amount greater than 0.035% by weight, based on the weight of the fiber.

37. The short fiber of claim 36, wherein the short fiber is a viscose fiber.

38. Short fiber according to claim 37, wherein the short fiber has a multi-section.

39. Short fiber according to one of claims 36 to 38, with a length-to-weight ratio of 1.0 to 6.0 dtex.

40. Short fiber according to one of claims 36 to 39, wherein the finish is selected from

Rl- (C0) _o -0- [-CH ₂ - (CH ₂ ) _m -0-] _n - (CO) p-Rl

(b) mono-, di- and ^• rasterization of sorbitans with fatty acids of the formula Rl-COOH, in which Rl is independently as defined above for each occurrence,

(d) imidazolium ethosulfates and methosulfates, and

(f) Mixtures of compounds according to (a), (b), (c), (d) or / and (e).

41. Use of a short fiber according to one of claims 36 to 40 in an airlaid process.

42. Absorbent article comprising a nonwoven fabric according to any one of claims 20 to 35, with an absorbency of at least 3 g / g nonwoven fabric.

43. The absorbent article of claim 42, wherein the article is a body hygiene article.

44. The absorbent article of claim 43, wherein the personal hygiene article is a tampon, sanitary napkin, diaper or incontinence article.

45. The absorbent article of claim 42, wherein the article is a household article, an industrial article, or a medical article.