Method of making spinnylies

The present invention relates to a method for producing spunbonded nonwovens, in which a spinning mass is extruded through the nozzle holes of at least one spinneret to form filaments, the filaments are stretched in the direction of extrusion and deposited on a first conveyor to form the spunbonded nonwoven, and in which the spunbonded nonwoven is at least one is subjected to laundry.

State of the art

The production of spunbonded nonwovens or nonwovens by the spunbond process on the one hand and by the meltblown process on the other hand is known from the prior art. In the spunbond process (e.g. GB 2 114 052 A or EP 3 088 585 A1), the filaments are extruded through a nozzle and drawn off and drawn through a drawing unit located underneath. In the meltblown process, on the other hand (e.g. 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 already entrained and stretched by the hot, fast process air as they exit the nozzle. With both technologies, the filaments are placed on a storage surface, for example a perforated conveyor belt, in a tangled position to form a fleece, transported to post-processing steps and finally wound up as fleece rolls.

It is also known from the prior art to produce cellulosic spunbonded nonwovens using spunbond technology (e.g. US Pat. No. 8,366,988 A) and using meltblown technology (e.g. US Pat. Nos. 6,358,461 A and US Pat. No. 6,306,334 A). A lyocell spinning mass is extruded and stretched according to the known spunbond or meltblown process, but before being laid to form a fleece, the filaments are additionally brought into contact with a coagulant in order to regenerate the cellulose and produce dimensionally stable filaments. Finally, the wet filaments are laid in a random orientation as a non-woven fabric.

In the case of a wash in particular, the advantages of the process can come into their own. In the production of thermoplastic spunbonded nonwovens, no washing is usually necessary, as this is a so-called "dry" spinning process, with any solvents that may be used evaporating from the spunbonded nonwoven by themselves after the calender or dryer. In the simplest case, the spunbonded nonwoven is wound into rolls immediately after extrusion and deposition. In the case of spinning processes that require washing, such as cellulosic spunbonded nonwovens, the throughput is usually limited by the length of the wash, since the spunbonded nonwovens are used to wash out the

Solvent must achieve certain residence times in the laundry. Particularly in the production of spunbonded nonwovens or nonwovens with very low basis weights, the processes mentioned suffer from the disadvantage that an increase in throughput is only possible to a very limited extent in a cost-effective manner and without impairing the quality of the spunbonded nonwovens, since in particular very long washing systems have to be used to achieve the same throughput and/or quality as at higher basis weights.

Since the spinning masses in cellulosic spunbond technologies only have a cellulose content of 3 to 17%, a larger amount of spinning mass is required to achieve a comparable throughput than in the production of thermoplastic spunbonded webs. As a result, more spinnerets have to be provided for the same productivity compared to thermoplastic spunbond systems, or more spinning mass throughput has to be achieved per spinneret. The spunbonded webs are then washed, consolidated, dried and wound up. WO 2018/071928 A1 describes a method for washing cellulosic spunbonded nonwovens. The connection between the residence time, the effectiveness of the wash and the effect on the costs and length of the wash is explained. Especially with high throughputs,2 , which are desirable for many applications, high conveying speeds are achieved. This increases both the demand for the effectiveness of the wash, as well as the required length for the wash and accordingly the effort for machine and plant construction and the costs for the plant and the very long building.

US 2005/0056956 A1 discloses a method for producing cellulosic spunbonded nonwovens, in which the filaments are laid down on a conveyor drum, hydroentangled, pressed and then laid down in the form of loops in a coagulation bath at a lower conveying speed. The loops are then undone again and the spunbonded nonwoven is dried and wound up. However, such a method has several disadvantages when used in commercial production plants. For example, at high production speeds, the speed of the depositing drum and the press rollers is very high, which in the case of wet cellulosic spunbonded nonwovens causes them to stick to the drum surface. This leads to tears and defects in the spunbonded nonwoven or the spunbonded web can wrap itself around the deposit drum and the press rollers, which is very disadvantageous for economic and safety reasons. In addition, the hydroentanglement of the spunbonded web immediately after the filaments have been deposited leads to the freshly extruded filaments being pressed in and partially sucked into the vacuum drum. This makes it even more difficult to detach the spunbonded nonwoven from the drum, which leads to further tears and defects in the spunbonded nonwoven. In addition, the structural changes introduced into the spunbonded web during hydroentanglement are caused by the subsequent coagulation baths and the associated In addition, the hydroentanglement of the spunbonded web immediately after the filaments have been deposited leads to the freshly extruded filaments being pressed in and partially sucked into the vacuum drum. This makes it even more difficult to detach the spunbonded nonwoven from the drum, which leads to further tears and defects in the spunbonded nonwoven. In addition, the structural changes introduced into the spunbonded web during hydroentanglement are caused by the subsequent coagulation baths and the associated In addition, the hydroentanglement of the spunbonded web immediately after the filaments have been deposited leads to the freshly extruded filaments being pressed in and partially sucked into the vacuum drum. This makes it even more difficult to detach the spunbonded nonwoven from the drum, which leads to further tears and defects in the spunbonded nonwoven. In addition, the structural changes introduced into the spunbonded web during hydroentanglement are caused by the subsequent coagulation baths and the associated

associated swelling of the spunbonded web completely or partially removed again. A targeted adjustment of the mechanical and structural properties of the spunbonded fabric produced is made significantly more difficult. In addition, the looped spunbonded nonwoven can only be transported through the coagulation bath at low conveying speeds, since the buoyancy force of the spunbonded nonwoven in the coagulation bath creates great resistance to the spunbonded nonwoven. An increase in throughput is therefore not possible without drastic losses in quality.

Disclosure of the Invention

The invention has therefore set itself the task of improving a method for producing spunbonded nonwovens of the type mentioned at the outset such that the throughput of the method can be increased in a cost-effective and simple manner without impairing the quality of the spunbonded nonwoven.

The object is achieved in that the spunbonded nonwoven is at least partially subjected to the laundry on a perforated second conveyor device at a lower conveying speed than the first conveyor device, the spunbonded nonwoven fabric being sprayed with washing liquid in the laundry and the washing liquid being at least partially discharged through the perforated second conveyor device .

If the spunbonded nonwoven is at least partially subjected to the wash on a second conveying device with a lower conveying speed than the first conveying device, i.e. the conveying speed of the spunbonded nonwoven is reduced during at least part of the wash compared to the conveying speed of the spunbonded nonwoven before the wash, the dwell time of the Spunbonded be increased in the wash without providing a cost-intensive longer wash. With a constant spinning mass throughput of the spinneret and a corresponding conveying speed when depositing the spunbonded nonwoven, a spunbonded nonwoven with a predefined basis weight can be obtained, the quality of the spunbonded nonwoven obtained, in particular its residual solvent content after washing, being improved.

Alternatively, by increasing the spinning mass throughput of the spinneret and correspondingly adjusting the conveying speed when depositing the spunbonded nonwoven, a spunbonded nonwoven with the same weight per unit area and consistent quality can be obtained with a higher throughput.

With the method according to the invention, the conveying speed, which, as shown above, results from the throughput of the spinning mass and the desired basis weight, can be completely decoupled from the conveying speed of the laundry. As a result, the length of the wash, the length of the plant or the building and thus also the costs for setting up and operating a plant for carrying out the method can be significantly reduced.

If the spunbonded fabric is further sprayed with washing liquid in the wash and the washing liquid is at least partially discharged through the perforated second conveying device, the reliability and efficiency of the wash can be further improved.

The assisted transport of the spunbonded nonwoven by the second conveying device during the wash can ensure reliable and efficient washing even at high conveying speeds, since there is no buoyancy and water resistance on the spunbonded nonwoven compared to a bath wash. Such a buoyancy or water resistance in a laundry bath can lead to entanglements or clumping in the spunbonded nonwoven and thus to the spunbonded nonwoven becoming unusable at high conveying speeds, for example from 100 m/min to 500 m/min. This is especially the case when the spunbonded web has a lower conveying speed within the wash than before the wash,

Due to the direct removal of the washing liquid via the perforated second conveying device, it is possible on the one hand to avoid flotation and on the other hand excessive swelling of the spunbonded nonwoven. A spunbonded nonwoven completely soaked in washing liquid can absorb 10 to 15 times the amount of liquid, based on its own weight. However, since spunbonded nonwovens that have never been dried have very low strength, such complete impregnation of the spunbonded fabric leads to further structural weakening and thus to increased tears, which prevents reliable onward transport. The throughput of the process can thus be increased by the washing according to the invention without negative effects on the quality of the spunbonded fabric produced.

After washing, the spunbonded nonwoven can preferably have a liquid content of less than 5 kg/kg, based on its dry weight. In a further embodiment, the liquid content can be less than 4 kg/kg, or in yet another preferred embodiment less than 3 kg/kg. Due to the low liquid content, the internal structure and stability of the spunbonded nonwoven can be retained, which means that transport is possible even at high conveying speeds.

For the purposes of the present invention, it is noted that a spunbonded nonwoven as used in the present disclosure is a nonwoven formed directly by laying down extruded filaments, the filaments being essentially continuous filaments and being laid in a random manner to form the spunbonded nonwoven.

A conveying device within the meaning of the present invention can be understood to mean all devices that are suitable for conveying or transporting the spunbonded nonwoven at a specific conveying speed. Such a conveyor device can be, for example, a conveyor belt, a conveyor drum, conveyor rollers or the like. In a preferred embodiment of the invention, the conveyor devices are designed as conveyor belts.

The aforementioned advantages can be achieved in particular when the conveying speed of the second conveying device is reduced by a factor of between 1 and 1000 compared to the first conveying device. For example, with a factor of 2, the throughput can be doubled with the basis weight and length of the laundry remaining the same, or the effectiveness of the laundry can be significantly improved. It has been shown, for example, that doubling the dwell time in the wash increases the efficiency more than linearly, and leads, for example, to a reduction of the solvent residues in the finished spunbonded nonwoven by a factor of 4 to 8. The conveying speed before washing is preferably reduced by a factor of between 1 and 100, or particularly preferably by a factor of between 1 and 25.

The reproducibility of the method can also be further improved if the spunbonded nonwoven is placed in loops on the second conveyor. In this way, it is particularly easy to react to the reduction in conveying speed in the laundry in terms of process engineering. The loops can have essentially parallel, superimposed sections on the spunbonded nonwoven, which enable efficient washing of the spunbonded nonwoven and can be pulled apart again after washing without damage. After washing, the loops can in particular be pulled apart again by a faster conveying device.

The spunbonded nonwoven can preferably be deposited on the second conveyor device immediately after the spunbonded nonwoven fabric has been deposited and formed on the first conveyor device. In this context, “immediately after depositing” is understood to mean that no further treatment steps of the spunbonded nonwoven are provided on the first conveyor device between the deposition and formation of the spunbonded nonwoven on the first conveyor device and the deposition on the second conveyor device.

In this case, the spunbonded nonwoven can be deposited on the second conveying device, preferably before washing, particularly preferably immediately before washing. A reduction in the conveying speed of the spunbonded fabric therefore takes place before washing or immediately before washing. In this context, “immediately before washing” is understood to mean that no further treatment steps of the spunbonded nonwoven are provided on the second conveyor device before washing. In this way, the spunbonded nonwoven can preferably run through the entire laundry on the second conveyor.

Accordingly, preferably no further treatment steps of the spunbonded fabric can be provided between the laying down and formation of the spunbonded fabric on the first conveyor device and the washing on the second conveyor device.

In addition, after washing, the spunbonded nonwoven can go through further treatment steps on a third conveying device with a higher conveying speed than the second conveying device. For this purpose, the spunbonded nonwoven can be deposited on the third conveying device, whereby - as described above - the overlength of the spunbonded nonwoven or any loops formed therein can be untangled again and the spunbonded nonwoven can be further processed again at a higher conveying speed. The third conveying device preferably has essentially the same conveying speed as the first conveying device.

If the conveying speed of the third conveying device is again increased by a factor of between 1 and 1000 compared to the second conveying device, a particularly versatile method can be provided which allows direct further processing of the spunbonded nonwoven after washing at a higher conveying speed. After washing, the spunbonded nonwoven can preferably be accelerated again to the same conveying speed as before washing and go through further treatment steps. The conveying speed of the third conveying device is preferably increased by a factor of between 1 and 100, particularly preferably by a factor of between 1 and 25, compared to the second conveying device.

The advantages mentioned above can be achieved in particular when the spunbonded nonwoven is subjected to hydroentanglement and/or drying after washing. The hydroentanglement can preferably be carried out at the original conveying speed of the spunbonded nonwoven, since this does not depend on longer dwell times compared to washing.

In addition, the provision of hydroentanglement after washing allows a particularly reliable control of the structural and internal properties of the spunbonded web. For example, in the course of hydroentanglement, patterns or perforations, which remain in the finished spunbond nonwoven, can be permanently embossed.

After hydroentanglement, the spunbonded nonwoven can also be dried to obtain a finished spunbonded nonwoven. The finished spunbonded nonwoven can then optionally be wound up into rolls in a winding device.

The washing efficiency can be further improved when the washing is a multi-stage countercurrent washing. In counter-current washing, the washing liquid used for washing, in particular water, circulates in several washing stages, with fresh washing liquid being fed in at the end of the washing and discharged via the perforated second conveyor and successively carried on in the same way to the upstream washing stages, and with at the beginning washing the used washing liquid is discharged.

The throughput of the process can be further increased if the spinning mass is also extruded through at least a first spinneret and a second spinneret to form filaments, with the filaments of the first spinneret being deposited on the first conveyor to form a first spunbonded nonwoven and the filaments of the second spinneret are deposited on the first conveyor to form a second spunbonded nonwoven, the filaments of the second spinneret being deposited over the first spunbonded nonwoven on the first conveyor to form the second spunbonded nonwoven to obtain a multi-layer spunbonded nonwoven.

If the filaments of the second spinneret to form the second spunbonded nonwoven are deposited on the first conveyor device over the first spunbonded nonwoven to obtain a multilayer spunbonded nonwoven, the throughput of the process can be increased in a simple manner, since at least two spinnerets are used for the simultaneous formation of at least two Spunbonded fabrics are provided, but the multilayer spunbonded fabric formed in this way can be further processed with the available means instead of a single spunbonded fabric. The second spinneret is preferably downstream of the first spinneret in the conveying direction of the first conveying device.

The resulting multi-layer spunbonded web consists of the first and second spunbonded webs, with the second spunbonded web being positioned over the first. The first and second spunbonded nonwoven can be connected to one another (e.g. by adhesion) in such a way that the multilayer spunbonded nonwoven forms a unit that can go through further process steps, but can be separated back into the first and second spunbonded nonwoven essentially without structural damage to them.

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

Likewise, the spinning mass can also be extruded through a third and further spinnerets to form filaments and the filaments can each be stretched in the direction of extrusion, with the filaments of the third spinneret being deposited on the first conveying device over the second spunbonded nonwoven to form a third spunbonded nonwoven around the multi-layer spunbonded nonwoven to obtain, or the filaments of the other spinnerets to form further spunbonded webs are deposited on the respective previous spunbonded web on the first conveyor to obtain the multi-layer spunbonded web.

Such a multi-layer spunbonded nonwoven can have a large number of spunbonded nonwovens, which can be separated from one another again in a later process step.

The above-mentioned advantages of the method can be particularly distinguished when the multi-layer spunbonded nonwoven is subjected to at least one treatment step before it is separated into at least the first and second spunbonded nonwoven. In this way, the first and second spunbonded nonwovens can be treated together in the form of a multilayer spunbonded nonwoven, and the throughput of the process can thus be significantly increased compared to the separate treatment of the spunbonded nonwovens.

This can be distinguished particularly when the at least one treatment step of the multi-layer spunbonded nonwoven fabric is the washing according to the invention on the second conveying device with a conveying speed that is reduced compared to the first conveying device. Because of the method according to the invention with joint washing of the first and second spunbonded nonwoven fabric in the multilayer spunbonded nonwoven fabric, the length of the wash can be significantly further reduced and the throughput can be increased.

The method according to the invention can be characterized by a high degree of flexibility if the spunbonded nonwoven is a multilayer spunbonded nonwoven, with at least two spinnerets arranged one behind the other being provided, so that the filaments extruded from the respective spinnerets each form a spunbonded nonwoven layer which is laid one on top of the other in such a way that the multi-layer spunbonded nonwoven is produced. The multi-layer spunbonded nonwoven can then still

can be reliably washed using the method according to the invention with a reduced conveying speed.

The reliability of the process can be further increased if the filaments are stretched by means of a stretching air stream after they have been extruded from the spinneret. In this way, the extrusion and stretching conditions of the filaments can be controlled in a targeted manner, and the internal properties of the spunbonded nonwoven can thus be adjusted. The stretching air flow is directed from the respective spinneret onto the extruded filaments.

In particular, the stretching 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 stretching air stream can also have a temperature of 20°C to 200°C, preferably 60°C to 160°C, particularly preferably 80°C to 140°C.

The method according to the invention can be particularly distinguished for the production of cellulosic spunbonded nonwovens, the spinning mass being a lyocell spinning mass, ie a solution of cellulose in a direct solvent for cellulose.

Such a direct solvent for cellulose is a solvent in which the cellulose is dissolved in non-derivatized form. This may preferably be a mixture of a tertiary amine oxide such as NMMO (N-methylmorpholine N-oxide) and water. Alternatively, for example, 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 variants 5% by weight to 15% by weight, and in particularly preferred variants 6% by weight to 14% by weight. -%.

In the production of cellulosic spunbonded nonwovens, the process according to the invention results in numerous improvements and advantages with regard to the economy of the production plant, operation of the plant and product quality. Since several parallel loops offset one above the other can be washed at the same time, the conveying speed of the spunbonded nonwoven can be significantly reduced during the wash. The lower conveying speed reduces both the costs and the complexity of the production plant.

Surprisingly, it has been shown that the spunbonded nonwoven laid down in parallel, superimposed loops at a reduced conveying speed can be washed with higher efficiency than a spunbonded nonwoven with a higher and non-reduced conveying speed. Even after a multi-stage countercurrent wash, the loops can be undone again without being destroyed and the spunbonded web can be accelerated back to the original conveying speed.

Even with low basis weights of up to 10g/m2 , it has been shown that the spunbonded nonwovens are stable enough to be laid in loops, washed at reduced speed and then accelerated again in order to then be consolidated, dried and wound up in further steps at the original conveying speed, if necessary to become.

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 advantages according to the invention can be distinguished in particular if the basis weight of the spunbonded nonwoven is between 5 g/m 2 (gsm) and 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 .

The conveying speed of the spunbonded nonwoven when it is laid down or the conveying speed of the first conveying device can preferably be between 1 m/min and 2000 m/min, preferably 10 m/min to 1000 m/min, particularly preferably 15 m/min to 500 m/min .

In addition, the internal structure of the spunbonded nonwoven fabric can be reliably controlled when the filaments extruded and drawn from the spinneret are partially coagulated.

For this purpose, the spinneret can be assigned a coagulation air flow containing a coagulation liquid for at least partial coagulation of the filaments, as a result of which the inner structure of the spunbonded nonwoven can be controlled in a targeted manner. A coagulation air flow can preferably be an aqueous fluid and/or a fluid containing coagulant, for example gas, mist, steam, etc.

A particularly reliable coagulation of the extruded filaments can be achieved when the coagulation liquid is a mixture of water and a direct solvent for cellulose. In particular, the coagulation liquid can be a mixture of 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.

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 2,500 l/h per meter of coagulation nozzle.

In the case of the spinnerets of the method according to the invention or the device according to the invention, single-row slotted nozzles, multi-row needle nozzles or preferably column nozzles with lengths of 0.1 m to 6 m can be used.

Brief description of the drawings

The embodiment variants of the invention are described in more detail below with reference to a drawing. 1 shows a schematic representation of the method and a device according to a first embodiment variant.

Ways to carry out the invention

1 shows a schematic representation of the method 100 according to a first embodiment variant for the production of cellulosic spunbonded nonwoven 1 and a corresponding device 200 by means of which the method 100 is carried out. In a first method step, a spinning mass 2 is produced from a cellulosic raw material and fed to a spinneret 3 of the device 200 . The cellulosic raw material for producing the spinning mass 2, which is not shown in detail in the figures, can be a conventional cellulose made from wood or other vegetable starting 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 spinning mass 2 is then extruded in the spinneret 3 through a large number of nozzle holes 4 to form the filaments 5 . By supplying drafting air 6 to a drafting unit in the spinneret 3, the filaments 5 are drawn when exiting the spinneret 3 by means of a drafting air stream. The stretching air 6 can emerge from openings in the spinneret 3 between the nozzle holes 4 and be directed as a stretching air stream directly onto the extruded filaments 5, which is not shown in detail in the figures. The extruded filaments 5 are subjected to a coagulation air stream 7 generated by a coagulation device 8 after or even during the stretching. The coagulation air stream 7 usually has a coagulation liquid, for example in the form of steam, mist, etc. The filaments 5 are at least partially coagulated by contact of the filaments 5 with the coagulation air flow 7 and the coagulation liquid contained therein, which in particular reduces adhesions between the individual extruded filaments 5 . The stretched and at least partially precipitated filaments 5 are then deposited in a tangled position on a first conveyor belt 9 as the first conveyor device 9 to form the spunbonded nonwoven 1 . The spunbonded nonwoven 1 is then transported further with the conveyor belt 9 to further processing steps 10 , 11 , 12 . Subsequently, the spunbonded nonwoven 1 is subjected to at least one wash 10 . which in particular reduces sticking between the individual extruded filaments 5 . The stretched and at least partially precipitated filaments 5 are then deposited in a tangled position on a first conveyor belt 9 as the first conveyor device 9 to form the spunbonded nonwoven 1 . The spunbonded nonwoven 1 is then transported further with the conveyor belt 9 to further processing steps 10 , 11 , 12 . Subsequently, the spunbonded nonwoven 1 is subjected to at least one wash 10 . which in particular reduces sticking between the individual extruded filaments 5 . The stretched and at least partially precipitated filaments 5 are then deposited in a tangled position on a first conveyor belt 9 as the first conveyor device 9 to form the spunbonded nonwoven 1 . The spunbonded nonwoven 1 is then transported further with the conveyor belt 9 to further processing steps 10 , 11 , 12 . Subsequently, the spunbonded nonwoven 1 is subjected to at least one wash 10 .

In order to increase the dwell time of the spunbonded nonwoven 1 in the laundry 10, the spunbonded nonwoven 1 is placed directly in front of the laundry 10 on a second conveyor belt 13 as a second conveyor device 13, which has a reduced conveying speed compared to the first conveyor device 9. The conveying speed of the spunbonded fabric 1 within the laundry 10 is therefore reduced compared to the conveying speed of the spunbonded fabric 1 before the laundry 10, ie while the filaments 5 are deposited on the first conveyor belt 9. The conveying speed is preferably reduced by a factor of between 1 and 1000. In a further embodiment, the factor is between 1 and 100, and in yet another embodiment between 1 and 25. In order to absorb the difference in the conveying speed between the first conveyor belt 9 and the second conveyor belt 13 in the spunbonded nonwoven 1 , the spunbonded nonwoven 1 is placed in loops 14 on the second conveyor belt 13 . The spunbonded fabric 1 placed in loops 14 is then subjected to washing 10, in which it is essentially freed from solvent residues from the spinning mass 2.

After washing 10, the spunbonded nonwoven 1 is deposited on a third conveyor belt 15, which has a higher conveying speed than the second conveyor belt 13. The third conveyor belt 15 preferably has the same conveying speed as the first conveyor belt 9, as a result of which the loops 14 are completely pulled out again. In a further embodiment variant, which is not shown in detail, the third conveyor belt 15 can also have a different conveying speed than the first conveyor belt 9, which compared to the second conveyor belt 13 is by a factor of between 1 and 1000, preferably between 1 and 100, in particular preferably between 1 and 25. On the third conveyor belt 15, the spunbonded nonwoven 1 is subjected to hydroentanglement 11, which can further adjust the internal structure of the spunbonded nonwoven 1.

Finally, the spunbonded nonwoven 1 is subjected to drying 12 in order to obtain a finished spunbonded nonwoven 1, with the process 100 being completed by optional winding 16 and/or packaging.

In another embodiment variant, which is only indicated in the figures, device 100 or method 200 can have at least a first spinneret 3 and a second spinneret 30, with spinning mass 2 simultaneously passing through first spinneret 3 and second spinneret 30 the filaments 5, 50 is extruded. The filaments 5, 50 are each stretched in the extrusion direction and at least partially coagulated, with the filaments 5 of the first spinneret 3 being deposited on the conveyor belt 9 to form a first spunbonded web 1 and the filaments 50 of the second spinneret 30 being deposited on the conveyor belt to form a second spunbonded web 9 are discarded. The filaments 50 of the second spinneret 30 are deposited on the conveyor belt 9 to form the second spunbonded nonwoven fabric over the first spunbonded fabric 1 in order to obtain a multi-layer spunbonded nonwoven fabric,

The first spunbonded nonwoven 1 and the second spunbonded nonwoven preferably pass through the laundry 10 together in the form of the multilayer spunbonded nonwoven, the multilayer spunbonded nonwoven being deposited in loops 14 on the second conveyor belt 13 at a lower conveying speed than the first conveyor belt 9 . Preferably, the multi-layer spunbonded nonwoven can then be separated again into at least the first spunbonded nonwoven 1 and the second spunbonded nonwoven in a step following washing 10, with the first spunbonded nonwoven 1 and second spunbonded nonwoven being separated after further steps, such as hydroentanglement 11 and/or the Drying 12, go through.

Alternatively, the first spunbonded nonwoven 1 and the second spunbonded nonwoven can also pass through the hydroentanglement 11 together and be permanently connected to one another to form the multilayer spunbonded nonwoven.

Likewise, the first spunbonded nonwoven 1 and the second spunbonded nonwoven can each have different inner properties, for example a different weight per unit area, and thus form a multilayer spunbonded nonwoven with variable cross-section properties.

In a further embodiment variant, which is not shown in the figures, the first conveyor device 9 is a conveyor drum and the second conveyor device 13 is a conveyor belt.

In yet another embodiment variant, both the first conveyor device 9 and the second conveyor device 13 are conveyor drums.

patent claims

1. A method for producing spunbonded nonwovens (1), in which a spinning mass (2) is extruded through the nozzle holes (4) of at least one spinneret (3, 30) to form filaments (5, 50), the filaments (5, 50) in are stretched in the direction of extrusion and deposited on a first conveyor (9) to form the spunbonded nonwoven (1), and in which the spunbonded nonwoven (1) is subjected to at least one wash (10), characterized in that the spunbonded nonwoven (1) is subjected to the wash (10 ) at least partially on a perforated second conveyor (13) with a lower conveying speed than the first conveyor (9), the spunbonded fabric (1) in the laundry (10) being sprayed with washing liquid and the washing liquid at least partially passing through the perforated second conveyor (13) is discharged.

2. The method according to claim 1, characterized in that the conveying speed of the second conveying device (13) compared to the first conveying device (9) by a factor of between 1 and 1000, in particular by a factor of between 1 and 100, particularly preferably by a factor of between 1 and 25, is reduced.

3. The method according to claim 1 or 2, characterized in that the spunbonded fabric (1) is deposited on the second conveyor (13) in loops (14).

4. The method according to any one of claims 1 to 3, characterized in that after washing (10) the spunbonded fabric (1) undergoes further treatment steps (11, 12 ) is subjected to.

5. The method according to claim 4, characterized in that the conveying speed of the third conveying device (15) compared to the second conveying device (13) by a factor of between 1 and 1000, in particular by a factor of between 1 and 100, particularly preferably by a factor of between 1 and 25, is increased.

6. The method according to claim 4 or 5, characterized in that the third conveyor (15) has essentially the same conveying speed as the first conveyor (9).

7. The method according to any one of claims 1 to 6, characterized in that the spunbonded fabric (1) after washing (10) is subjected to hydroentanglement (11) and/or drying (12).

8. The method according to any one of claims 1 to 7, characterized in that the wash (10) is a multi-stage countercurrent wash.

9. The method according to any one of claims 1 to 8, characterized in that the spunbonded fabric (1) is deposited on the second conveyor (13) immediately after being deposited and formed on the first conveyor (9).

10. The method according to any one of claims 1 to 9, characterized in that the spunbonded fabric (1) is deposited immediately before the wash (10) on the second conveyor (13).

11. The method according to any one of claims 1 to 10, characterized in that the spinning mass (2) is extruded through at least a first spinneret (3) and a second spinneret (30) to form filaments (5, 50), the filaments (5 ) of the first spinneret (3) to form a first spunbonded fabric (1) are deposited on the first conveyor (9) and the filaments (50) of the second spinneret (30) to form a second spunbonded fabric are deposited on the first conveyor (9). , wherein the filaments (50) of the second spinneret (30) for forming the second spunbonded nonwoven fabric are deposited on the first conveyor device (9) over the first spunbonded nonwoven fabric (1) in order to obtain a multi-layer spunbonded nonwoven fabric.

12. The method according to claim 11, characterized in that the multi-layer spunbonded nonwoven is separated into at least the first spunbonded nonwoven (1) and the second spunbonded nonwoven in a subsequent step, in particular after washing (10).

13. The method according to any one of claims 1 to 12, characterized in that the spunbonded fabric (1) is a cellulosic spunbonded fabric (1) and the spinning mass (2) is a solution of cellulose in a direct solvent, in particular a tertiary amine oxide.

14. The method according to any one of claims 1 to 13, characterized in that the filaments (5, 50) after extrusion from the spinneret (3, 30) are at least partially coagulated, in particular the spinneret (3, 30) one, one coagulation air stream (7) containing coagulation liquid for at least partial coagulation of the filaments (5, 50).

15. The method according to any one of claims 1 to 14, characterized in that the coagulation liquid is a mixture of water and the direct solvent for cellulose, in particular a tertiary amine oxide.