EP4077790A1

EP4077790A1 - Method for producing spunbonded fabric

Info

Publication number: EP4077790A1
Application number: EP20821213.4A
Authority: EP
Inventors: Ibrahim SAGERER-FORIC
Original assignee: Lenzing AG; Chemiefaser Lenzing AG
Current assignee: Lenzing AG
Priority date: 2019-12-17
Filing date: 2020-12-11
Publication date: 2022-10-26
Also published as: CN115066525A; WO2021122378A1; US20230051927A1; TW202130874A

Abstract

The invention relates to a method (100, 101) for producing spunbonded fabrics (1.1, 1.2, 1.3) and to an apparatus (200, 201) for producing spunbonded fabrics (1.1, 1.2, 1.3), wherein, in the method (100, 101), a spinning compound (2) is extruded into filaments (5.1, 5.2, 5.3) through a multiplicity of nozzle holes (4.1, 4.2, 4.3) at least of a first spinneret (3.1) and of a second spinneret (3.2) and the filaments (5.1, 5.2, 5.3) are each drafted in the extrusion direction, wherein the filaments (5.1) of the first spinneret (3.1), in order to form a first spunbonded fabric (1.1), are laid on the conveyor belt (9) and the filaments (5.2) of the second spinneret (3.2), in order to form a second spunbonded fabric (1.2) over the first spunbonded fabric (1.1), are laid on the conveyor belt (9) in order to obtain a multilayer spunbonded fabric (10). In order to increase the throughput of the method, it is proposed that the multilayer spunbonded fabric (10) is separated in a subsequent step into at least the first spunbonded fabric (1.1) and second spunbonded fabric (1.2) and the first and second spunbonded fabrics (1.1, 1.2), following separation, each individually undergo water-jet consolidation (15.1, 15.2) and optionally drying (12), and/or are each individually wound up.

Description

Method of making spinnylies

The present invention relates to a method for the production of spunbonded nonwovens, in which a spinning mass is extruded through a plurality of nozzle holes of at least one first spinneret and a second spinneret to form filaments and the filaments are each stretched in the extrusion direction, the filaments of the first spinneret to form one first spunbonded nonwovens are deposited on the conveyor belt and the filaments of the second spinning nozzle to form a second spunbonded nonwoven are deposited over the first spunbonded nonwoven on the conveyor belt in order to obtain a multi-layer spunbonded nonwoven.

State of the art

The production of spunbonded nonwovens or nonwovens using the spunbond method on the one hand and the meltblown method on the other hand is known from the prior art. In the spunbond process (for example GB 2 114052 A or EP 3 088 585 A1) the filaments are extruded through a nozzle and drawn off and stretched by a stretching unit below. In the meltblown process, on the other hand (for example US Pat. No. 5,080,569 A, US Pat. No. 4,380,570 A or US Pat. No. 5,695,377 A), the extruded filaments are entrained and stretched by hot, fast process air as soon as they exit the nozzle. With both technologies, the filaments are placed on a storage surface, for example a perforated conveyor belt, in a random layer to form a nonwoven, transported to post-processing steps and finally wound up as nonwoven rolls.

It is also known from the prior art to produce cellulosic spunbonded nonwovens according to the spunbond technology (e.g. US Pat. No. 8,366,988 A) and according to meltblown technology (e.g. US Pat. No. 6,358,461 A and US Pat. No. 6,306,334 A). A Lyocell spinning mass is extruded and stretched according to the known spundbond or meltblown processes, but before being deposited into a fleece, the filaments are additionally brought into contact with a coagulant in order to regenerate the cellulose and produce dimensionally stable filaments. The wet filaments are finally laid down in a random layer as a nonwoven fabric.

The prior art (US 2018/0282922 A1) also discloses methods for producing spunbonded fabrics in which a spinning mass is extruded at least through a first spinneret and a second spinneret downstream of the first spinneret, so that the filaments extruded from the second spinneret over which filaments extruded from the first spinneret are deposited, forming a multi-layer spunbonded nonwoven. Particularly in the production of spunbonded nonwovens or nonwovens with very low surface weights, the processes mentioned suffer from the disadvantage that an increase in throughput is only possible to a very limited extent without impairing the quality of the spunbonded nonwovens.

Disclosure of the invention

The invention has therefore set itself the task of improving a method for producing spunbonded nonwoven of the type mentioned at the outset in such a way that the throughput of the method can be increased in a cost-effective and simple manner.

The object is achieved in that, in a subsequent step, the multi-layer spunbonded nonwoven is separated into at least the first spunbonded nonwoven and the second spunbonded nonwoven and, after the separation, the first and second spunbonded nonwoven each go through a hydroentanglement and optionally a drying, and / or are each wound up individually .

If the filaments of the second spinning nozzle to form the second spunbonded web are deposited over the first spunbonded web on the conveyor belt in order to obtain a multilayered spunbonded web, the throughput of the process can be increased in a simple manner, since at least two spinning nozzles are provided for the simultaneous formation of at least two spunbonded webs be, but the multi-layer spunbonded nonwoven formed can be further processed with the available means instead of a single spunbonded nonwoven. The second spinneret is preferably located downstream of the first spinneret in the conveying direction of the conveyor belt.

The multi-layer spunbonded nonwoven formed in the process consists of the first and second spunbonded nonwoven, the second spunbonded nonwoven being arranged above the first. The first and second spunbond can be connected to one another (for example by adhesion) in such a way that the multi-layer spunbond forms a unit that can go through further process steps, but can be separated again into these essentially without structural damage to the first and second spunbond.

If the multi-layer spunbonded web is separated into at least the first and second spunbonded web in a subsequent step, at least two independent spunbonded webs can again be obtained in the course of the process. A cost-effective method for producing spunbonded nonwoven with increased throughput can thus be created.

Likewise, the spinning mass can also be extruded into filaments through a third and further spinning nozzle and the filaments are each stretched in the extrusion direction, the filaments of the third spinning nozzle to form a third spunbond over the second Spunbond can be placed on the conveyor belt in order to obtain the multi-layer spunbond, or the filaments of the further spinning nozzles to form further spunbond are placed over the respective preceding spunbond on the conveyor belt in order to obtain the multi-layer spunbond. Such a multi-layer spunbonded web can have a large number of spunbonded webs, which can be separated from one another again in a later process step.

For the sake of clarity, the following statements each relate to an embodiment with two spinnerets, but are in no way to be regarded as restrictive. Rather, these can be transferred to any number of spinnerets.

The method can be particularly noteworthy if the first and second spunbonded nonwovens each undergo a separate hydroentanglement process after being separated. By arranging the hydroentanglement after the multi-layer spunbonded web has been severed, a disadvantageous connection between the first and second spunbonded nonwoven in the multi-layer spunbonded nonwoven can be avoided, which would make a later non-destructive separation of the multi-layered spunbonded nonwoven more difficult. The separate hydroentanglement of the spunbonded nonwovens can then advantageously improve the internal structure or the internal cohesion. In particular, the first and second spunbonded nonwovens can also individually go through a drying process after the respective hydroentanglement in order to obtain finished spunbonded nonwovens that can be wound up.

The finished treated or separated spunbonded webs can then each be wound up individually in order to obtain at least two spunbonded webs at the same time.

For the purposes of the present invention, it is stated that a spunbonded nonwoven in the sense of the present disclosure is understood to mean a nonwoven fabric which is formed directly by depositing extruded filaments, the filaments being essentially continuous filaments and being laid in a random position to form the spunbonded nonwoven.

The aforementioned advantages of the method can be particularly noticeable when the multi-layer spunbonded nonwoven passes through at least one treatment step before it is separated into at least the first and second spunbonded nonwoven. This is because a joint treatment of the first and second spunbonded nonwovens can take place in the form of the multilayered spunbonded nonwoven and thus the throughput of the method can be significantly increased compared to the separate treatment of the spunbonded nonwovens.

This can be particularly noticeable when the at least one treatment step of the multi-layer spunbonded nonwoven is washing or drying. In addition, the at least one treatment step of the multi-layer spunbond can also be a hydroentanglement, the first and second spunbond remaining non-destructively separable after the hydroentanglement in the multi-layer spunbond.

The advantages of the process can be particularly evident in the case of laundry. In the manufacture of thermoplastic spunbond nonwovens, washing is usually not necessary, as it is a so-called “dry” spinning process, whereby any solvents that may be used evaporate from the spunbonded by themselves after the calender or dryer. In the simplest case, the spunbonded nonwoven is wound up into rolls immediately after extrusion and deposition in such a process. In the case of spinning processes that require washing, such as cellulosic spunbonded fabrics, the throughput is generally limited by the length of the laundry, since the spunbonded fabrics have to achieve certain dwell times in the laundry to wash out the solvent. With very low basis weights, very long washing systems would have to be used in order to achieve the same throughput as with higher basis weights. The method according to the invention with washing the first and second spunbonded nonwoven together in the multi-layer spunbonded nonwoven can therefore significantly reduce the length of the laundry or increase the throughput. Furthermore, the residual solvent content in the spunbonded nonwoven produced can be reduced.

According to the invention, it has been shown that the reduction in the production speed and the increase in dwell time obtained as a result have a very strong effect on the effectiveness of the laundry and on the residual content of the solvent in the finished spunbonded nonwoven.

For example, the production speed in the manufacture of single-layer spunbonded nonwoven with a weight per unit area of ^{40 g / m 2} with a cellulose throughput of 300 kg / h / m is 125 m / min. In the multilayer production of single-layer spunbonded nonwovens according to the invention, the individual spunbonded nonwovens already have a weight per unit area of 40 g / m ² . The production speed is then reduced to 62.5 m / min with two superimposed spunbonded fabrics and 300kg / h / m cellulose throughput. It has been shown that the effectiveness of the individual washing stages is not only doubled, but up to eightfold. Since the dwell time has a serious effect on the efficiency of the laundry, doubling the dwell time can lead to 4 to 8 times less residual solvent in the spunbonded nonwoven.

The cost of the process can be further reduced if the wash is a multi-stage countercurrent wash. In countercurrent washing, the water used for washing circulates in several washing stages, with fresh water being added at the end of the washing and being successively carried on to the upstream washing stages, and the used washing water being discharged at the beginning of the washing. The first and second spinning nozzles for drawing the filaments are preferably each assigned a drawing air stream. The spinnerets can thus control the extrusion and drawing conditions of the filaments independently of one another, and thus produce two independent and mutually different first and second spunbonded nonwovens. A particularly flexible and versatile process can thus be created. The drawing air stream is directed from the respective spinneret onto the extruded filaments. In particular, the drawing air stream can have a pressure of 0.05 bar to 5 bar, preferably 0.1 bar to 3 bar, particularly preferably 0.2 bar to 1 bar. In particular, the drawing air stream can furthermore have a temperature of from 20 ° C. to 200 ° C., preferably from 60 ° C. to 160 ° C., particularly preferably from 80 ° C. to 140 ° C.

The method according to the invention is particularly suitable for the production of cellulosic spunbonded nonwovens, the spinning mass being a lyocell spinning mass, that is to say a solution of cellulose in a direct solvent for cellulose. Such a direct solvent for cellulose is a solvent in which the cellulose is present in dissolved form in a non-derivatized form. This can preferably be a mixture of a tertiary amine oxide, such as NMMO (N-methylmorpholine-N-oxide), and water. Alternatively, however, ionic liquids or mixtures with water are also suitable as direct solvents. The cellulose content in the spinning mass can be 3% by weight to 17% by weight, in preferred embodiment variants 5% by weight to 15% by weight, and in particularly preferred embodiment variants 6% by weight to 14% by weight. -%.

Since the cellulose spinning masses in processes for the production of cellulosic spunbonded webs only have cellulose contents of a maximum of 17%, a larger amount of spunbonded material is required in cellulosic spunbonded web technologies than in the production of thermoplastic spunbonded webs in order to achieve the same productivity. As a result, more spinning nozzles or more spinning mass throughput per spinneret must be achieved with the same productivity compared to thermoplastic spunbond systems. The individual layers are then washed, consolidated, dried and wrapped.

In WO 2018/071928 A1 a method for washing cellulosic spunbonded nonwovens is described. The relationship between the dwell time, the effectiveness of the laundry and the effect on the costs or the length of the laundry is explained. In particular with a high cellulose throughput, which is important for the economy of the process, and with low weights per unit area of up to 10 g / m ² , which are desirable for many applications, high production speeds have to be achieved. This increases the demands on the effectiveness of each individual washing stage, as well as the length required for the Laundry and, accordingly, the effort for machine and plant construction and the costs for the plant or the corresponding long building.

However, a high throughput is necessary for the economic operation of a plant for the production of cellulosic spunbonded nonwovens. The method according to the invention can ensure a higher throughput or shortening of the laundry, particularly in the production of cellulosic spunbonded nonwovens.

The throughput of cellulose per spinneret can preferably be between 5 kg / h per meter of spinneret length and 500 kg / h per meter of spinneret length.

The internal structure of the spunbonded nonwovens can also be reliably controlled if the filaments of the first and second spinning nozzle are at least partially coagulated.

For this purpose, the first and second spinning nozzle can each be assigned a coagulation air stream, which has a coagulation liquid, for at least partial coagulation of the filaments, whereby the internal structure of the first and second spunbond can be controlled independently of one another. A stream of coagulation air can preferably be a fluid containing water and / or a fluid containing coagulant, for example gas, mist, steam, etc.

A particularly reliable coagulation of the extruded filaments can be achieved if the coagulation liquid is a mixture of water and a direct solvent for cellulose. In particular, the coagulation liquid can be a mixture of fully deionized water and 0% by weight to 40% by weight NMMO, preferably 10% by weight to 30% by weight NMMO, particularly preferably 15% by weight to 25% by weight. % NMMO, be.

The amount of coagulation liquid can preferably be 50 l / h to 10,000 l / h, more preferably 100 l / h to 5,000 l / h, particularly preferably 500 l / h to 2,5001 / h per meter of coagulation nozzle.

The second spunbonded nonwoven can preferably have a weight per unit area different from the first spunbonded nonwoven, as a result of which a particularly flexible method can be created. The weight per unit area of the first and second spunbonded nonwoven can be 5 g / m ² (gsm) to 500 g / m ² , preferably 10 g / m ² to 250 g / m ² , particularly preferably 15 g / m ² to 100 g / m ² , amount. The invention has also set itself the task of improving a device for producing spunbonded nonwoven according to the preamble of claim 12 in such a way that it enables an increase in production throughput in a structurally simple and cost-effective manner.

The problem posed is achieved by the characterizing part of claim 12.

If the second spinning nozzle of the device is arranged in the conveying direction of the conveyor belt after the first spinning nozzle in such a way that the second spunbonded web is deposited on the conveyor belt over the first spunbonded web to form a multilayered spunbonded web, a device can be created in a structurally simple manner which consists of two spunbond webs forms existing multi-layer spunbond on the conveyor belt. If the device also has a separating device fed via the conveyor belt for separating the multi-layer spunbonded web into individual spunbonded webs, a compact and inexpensive device with increased throughput can also be provided by the multi-layered spunbonded web being conveyed together again into its individual spunbonded webs by the separating device is separated

The aforementioned advantages can be particularly noticeable in a device which has a laundry for washing the multi-layer spunbonded nonwoven fabric, which is arranged in the conveying direction of the conveyor belt between the spinneret and the separating device. Thus, the device can namely provide a common wash with increased throughput for the multi-layer spunbonded web before the multi-layered spunbonded web is separated again into the individual spunbonded webs in the separating device.

If the device has at least a first and a second winding device, the winding devices being fed by the severing device, a structurally simple device with high throughput can be created which enables individual spunbonded nonwovens to be obtained simultaneously.

In addition, the device can have at least a first and a second hydroentanglement, with hydroentanglement being provided between a severing device and a winding device. The hydroentanglement are each fed from the splitting device with the spunbonded nonwovens and can also subject them to hydroentanglement. After hydroentangling, the spunbonded nonwovens are transferred to the winding device.

In the case of the spinning nozzles of the method according to the invention or the device according to the invention, it is preferable for those known from the prior art (US Pat. US 4,380,570 A, WO 2019/068764 A1) single-row slot nozzles, multi-row needle nozzles or preferably column nozzles with lengths of 0.1 m to 6 m are used.

Brief description of the drawings

The embodiments of the invention are described in more detail below with reference to the drawings. Show it:

1 shows a schematic representation of the method and a device according to a first embodiment variant, and

2 shows a schematic representation of the method and a device according to a second embodiment variant.

Ways of Carrying Out the Invention

1 shows a schematic representation of the method 100 according to a first embodiment of the invention for the simultaneous production of several cellulosic spunbonded nonwovens 1.1, 1.2, 1.3 and a corresponding device 200 for carrying out the method. In a first process step, a spinning mass 2 is produced from a cellulosic raw material and fed to a first spinneret 3.1, a second spinneret 3.2 and a third spinneret 3.3 of the device 200. The cellulosic raw material for the production of the spinning mass 2, which production is not shown in detail in the figures, can be a conventional pulp made of wood or other vegetable raw materials. However, it is also conceivable that the cellulosic raw material consists of production waste from spunbond production or recycled textiles. The spinning mass 2 is a solution of cellulose in NMMO and water, the cellulose content in the sense mass being between 3% by weight and 17% by weight.

The device 200 has three spinnerets 3.1, 3.2, 3.3 for extrusion of a spinning mass 2 into filaments 5.1, 5.2, 5.3. The spinning mass 2 is extruded in the spinnerets 3.1, 3.2, 3.3 through a plurality of nozzle holes 4.1, 4.2, 4.3, which are assigned to the respective spinneret 3.1, 3.2, 3.3, to form the filaments 5.1, 5.2, 5.3. Each spinneret 3.1, 3.2, 3.3 also has stretching devices 4.1, 4.2, 4.3 for stretching the extruded filaments 5.1, 5.2, 5.3, whereby the first, second and third spinnerets 3.1, 3.2, 3.3 are each assigned a stretching air stream for the stretching. For this purpose, stretching air 6 is fed to the stretching devices in the spinnerets 3.1, 3.2, 3.3 and the filaments 5.1, 5.2, 5.3 are stretched in the extrusion direction by the stretching air flow as they exit from the spinnerets 3.1, 3.2, 3.3. The stretching air 6 can from openings in the Spinning nozzles 3.1, 3.2, 3.3 emerge between the nozzle holes 4.1, 4.2, 4.3 and are directed as a stretching air stream directly onto the extruded filaments 5.1, 5.2, 5.3.

The extruded filaments 5.1, 5.2, 5.3 are preferably acted upon by a coagulation air stream 7.1, 7.2, 7.3 after or already during the stretching, with at least one coagulation air stream 7.1, 7.2, 7.3 being assigned to the spinnerets 3.1, 3.2, 3.3 and by a coagulation device 8.1, 8.2, 8.3 is generated. The

Coagulation air streams 7.1, 7.2, 7.3 usually have a coagulation liquid, for example in the form of steam, mist, etc. By contact of the filaments 5.1, 5.2, 5.3 with the coagulation air stream 7.1, 7.2, 7.3 and the coagulation liquid contained therein, the filaments 5.1 , 5.2, 5.3 at least partially coagulated, which in particular reduces adhesions between the individual extruded filaments 5.1, 5.2, 5.3.

The drawn and at least partially coagulated filaments 5.1 of the first spinneret 3.1 are then placed in a random position on a conveyor belt 9 of the device 200 to form a first spunbonded web 1.1. The second spinneret 3.2 is arranged in the conveying direction of the conveyor belt 9 after the first spinneret 3.1 in such a way that the drawn and at least partially coagulated filaments 5.2 of the second spinning nozzle 3.2 are deposited in a random position over the first spunbond 1.1 on the conveyor belt 9 to form a second spunbond 1.2. In the same way, the drawn and at least partially coagulated filaments 5.3 of the third spinneret 3.3 are deposited over the second spunbond 3.2 on the conveyor belt 9, namely by the third spinneret 3.3 being arranged in the conveying direction of the conveyor belt 9 after the second spinneret 3.2.

By placing the second spunbond 1.2 over the first spunbond 1.1 and the third spunbond 1.3 over the second spunbond 1.2, a multi-layer spunbond 10 is formed in which the spunbond 1.1, 1.2, 1.3 are detachably connected to one another. The detachable connection between the spunbonded nonwovens 1.1, 1.2, 1.3 to the multi-layer spunbonded nonwoven 10 is designed in such a way that a non-destructive separation of the multi-layered spunbonded nonwoven 10 into the individual spunbonded nonwovens 1.1, 1.2, 1.3 is possible even after further treatment steps.

The multilayer spunbonded nonwoven 10 is passed after the formation over the conveyor belt 9 through a laundry 11 in which the multilayered spunbonded nonwoven 10 is washed in order to free it from residues of the solvent, namely the NMMO contained in the spinning mass 2. In a preferred embodiment variant, the washing 11 is a multi-stage countercurrent washing, which, however, was not shown in the figures. The washed multilayer spunbonded nonwoven 10 is then fed to a drying unit 12 in a next step in order to remove the remaining moisture. The laundry 11 is in particular in The conveying direction of the conveyor belt 9 is arranged between the spinnerets 3.1, 3.2, 3.3 and a later separating device 13.

In a further embodiment, which is not shown in detail in the figures, the multi-layer spunbond 10 can undergo additional hydroentanglement, the spunbond 1.1, 1.2, 1.3 in the multi-layer spunbond 10 still remaining non-destructively separable.

The washed and dried multi-layer spunbond 10 is separated into the first spunbond 1.1, the second spunbond 1.2 and the third spunbond 1.3 in a separating device 13 fed by the conveyor belt 9 with the multi-layer spunbond 10, the spunbond 1.1, 1.2, 1.3 each separating one Winding device 14.1, 14.2, 14.3 are fed in order to simultaneously obtain the finished spunbonded nonwovens 1.1, 1.2, 1.3. The separating device 13 has an inlet for the multi-layer spunbonded nonwoven 10, and several outputs for the spunbonded nonwovens 1.1, 1.2, 1.3, the input of the separating device 13 being connected to the dryer 12, and the outputs each being connected to the winding devices 14.1, 14.2,

14.3 are connected to feed them with the spunbonded fabrics 1.1, 1.2, 1.3.

2 shows a schematic representation of a method 101 for the simultaneous production of several cellulosic spunbonded nonwovens 1.1, 1.2, 1.3, according to a second embodiment of the invention, as well as a corresponding device 201 for carrying out the method 101 - as described above for the method 200 of the first embodiment - fed to a first spinneret 3.1, a second spinneret 3.2 and a third spinneret 3.3 of the device 201 and extruded, stretched and at least partially coagulated into filaments 5.1, 5.2, 5.3.

The stretched and at least partially coagulated filaments 5.1 of the first spinning nozzle 3.1 are then again placed in a random position on the conveyor belt 9 to form a first spunbonded web 1.1, the filaments 5.2 of the second spinning nozzle 3.2 are placed over the first spunbonded web 1.1 in a randomized manner to form a second spunbonded web 1.2 deposited on the conveyor belt 9, and the filaments 5.3 of the third spinneret 3.3 are used to form a third spunbond

1.3 deposited in a random position over the second spunbond 3.2 on the conveyor belt 9. As described above, a multi-layer spunbonded nonwoven 10 is formed in which the spunbonded nonwovens 1.1, 1.2, 1.3 are arranged one above the other and are releasably connected to one another.

The multi-layer spunbond 10 is then guided over the conveyor belt 9 through a laundry 11 in which the multi-layer spunbond 10 is washed and freed from solvent residues (in particular NMMO). In contrast to the first embodiment variant in FIG. 1, the multi-layer spunbonded nonwoven 10 is fed to a severing device 13 after washing 11 and separated into the first spunbond 1.1, the second spunbond 1.2 and the third spunbond 1.3.

In comparison with the device 101 according to FIG. 1, the device 201 has a plurality of hydroentanglement 15.1, 15.2, 15.3 for the individual spunbonded nonwovens 1.1, 1.2, 1.3. The spunbonded nonwovens 1.1, 1.2, 1.3 then each separately pass through a hydroentanglement 15.1, 15.2, 15.3, in which the mechanical properties of the spunbonded nonwovens 1.1, 1.2, 1.3 can be changed or influenced separately from one another. For example, in the course of the hydroentanglement, 15.1, 15.2, 15.3 perforation patterns, embossing patterns or the like can be introduced into the spunbonded nonwovens 1.1, 1.2, 1.3, although this was not shown in detail in the figures. The hydroentanglement 15.1, 15.2, 15.3 are each provided between the severing device 13 and later winding device 14.1, 14.2, 14.3 for the spunbonded nonwovens 1.1, 1.2, 1.3.

The spunbonded webs 1.1, 1.2, 1.3 are then brought together again for common drying 12, and after the common drying 12 again separated into the individual spunbonded webs 1.1, 1.2, 1.3 and fed to the respective winding devices 14.1, 14.2, 14.3. Separate merging and separating devices can be provided for bringing together and severing the spunbonded nonwovens 1.1, 1.2, 1.3 before and after drying 12, which is not shown in the figures.

In an alternative embodiment to the method 101 shown in FIG. 2, which is not shown in more detail in the figures, the drying 12 can after the separation of the multilayer spunbond 10 in the separating device 13 and after the hydroentanglement 15.1, 15.2, 15.3 for each spunbond 1.1, 1.2, 1.3 take place separately. The spunbonded nonwovens 1.1, 1.2, 1.3 do not have to be brought together before drying 12 and then separated again.

In a further embodiment of the invention, the spunbonded nonwovens 1.1, 1.2, 1.3 can be produced by the spinnerets 3.1, 3.2, 3.3 each with different weights per unit area, for example by changing the mass throughput through the spinnerets 3.1, 3.2, 3.3.

Claims

1. A method for producing spunbonded nonwovens (1.1, 1.2, 1.3), in which a spinning mass (2) through a plurality of nozzle holes (4.1, 4.2, 4.3) at least one first spinneret (3.1) and a second spinneret (3.2) to filaments (5.1, 5.2, 5.3) are extruded and the filaments (5.1, 5.2, 5.3) are each stretched in the extrusion direction, the filaments (5.1) of the first spinneret (3.1) to form a first spunbond (1.1) on the conveyor belt (9) are deposited and the filaments (5.2) of the second spinning nozzle (3.2) to form a second spunbond (1.2) are deposited over the first spunbond (1.1) on the conveyor belt (9) in order to obtain a multi-layer spunbond (10), characterized in that, that the multi-layer spunbond (10) is separated in a subsequent step into at least the first spunbond (1.1) and second spunbond (1.2) and the first and second spunbond (1.1, 1.2) are each separated individually by hydroentanglement (15.1, 15.2) and against also pass through a drying process (12) and / or are each wound up individually.

2. The method according to claim 1, characterized in that the multi-layer spunbond (10) goes through at least one treatment step (11, 12) before it is separated into at least the first and second spunbond (1.1, 1.2).

3. The method according to claim 2, characterized in that the at least one treatment step (11, 12) of the multi-layer spunbonded nonwoven (10) is selected from the group consisting of: a wash (11), a drying (12).

4. The method according to claim 3, characterized in that the wash (11) is a multi-stage countercurrent wash.

5. The method according to any one of claims 2 to 4, characterized in that the at least one treatment step (11, 12) of the multi-layer spunbond (10) is a hydroentanglement, the first and second spunbond (1.1, 1.2) after the hydroentanglement in the multi-layer Spunbond (10) remain non-destructive separable.

6. The method according to any one of claims 1 to 5, characterized in that the first and second spinnerets (3.1, 3.2) are each assigned a drawing air stream for drawing the filaments (5.1, 5.2).

7. The method according to any one of claims 1 to 6, characterized in that the spunbond (1.1, 1.2, 1.3) is a cellulosic spunbond (1.1, 1.2, 1.3), and the spinning mass (2) is a solution of cellulose in a direct solvent, particularly a tertiary amine oxide.

8. The method according to any one of claims 1 to 7, characterized in that the filaments (5.1, 5.2) after extrusion from the first and second spinneret (3.1, 3.2) are at least partially coagulated.

9. The method according to claim 8, characterized in that the first and second

Spinneret (3.1, 3.2) each having a coagulation liquid

Coagulation air flow (7.1, 7.2) for at least partial coagulation of the filaments (5.1, 5.2) is assigned.

10. The method according to claim 9, characterized in that the coagulation liquid is a mixture of water and a direct solvent for cellulose, in particular a tertiary amine oxide.

11. Device for the production of spunbonded nonwoven (1.1, 1.2, 1.3), with at least one first spinneret (3.1) and a second spinneret (3.2) for extrusion of a spinning mass (2) into filaments (5.1, 5.2, 5.3), the spinnerets (3.1, 3.2, 3.3) have stretching devices (4.1, 4.2, 4.3) for stretching the extruded filaments (5.1, 5.2, 5.3), and with a conveyor belt (9) for depositing and forming the stretched filaments (5.1, 5.2, 5.3) at least one first and second spunbond (1.1, 1.2), characterized in that the second spinning nozzle (3.2) is arranged in the conveying direction of the conveyor belt (9) after the first spinning nozzle (3.1) in such a way that the second spunbond (1.2) on the conveyor belt ( 9) is deposited over the first spunbond (1.1) to form a multi-layer spunbond (10), and that the device (200, 201) has a cutting device (13) fed via the conveyor belt (9) for cutting the multi-layer spunbond (10) into individual spunbonded nonwovens (1.1, 1.2, 1.3), having.

12. The device according to claim 11, characterized in that the device (200, 201) has a laundry (11) for washing the multi-layer spunbonded nonwoven (10), which in the conveying direction of the conveyor belt (9) between spinnerets (3.1, 3.2, 3.3) and

Separating device (13) is arranged.

13. The device according to claim 11 or 12, characterized in that the device (200, 201) has at least a first and a second winding device (14.1, 14.2), wherein the winding devices (14.1, 14.2, 14.3) through the severing device (13) be fed.

14. The device according to claim 13, characterized in that the device (200, 201) has at least a first and a second hydroentanglement (15.1,

15.2), a hydroentanglement (15.1, 15.2, 15.3) being provided between a separating device (13) and a winding device (14.1, 14.2, 14.3).