EP3575468B1 - Device and method for the manufacture of woven material from continuous filaments - Google Patents

Description

The invention relates to a device for producing spunbonded nonwovens from continuous filaments, in particular from continuous filaments made of thermoplastic material, a spinnerette being provided for spinning the continuous filaments and a cooling chamber for cooling the spun filaments with cooling air, furthermore a drawing device for drawing the filaments and a storage device for depositing the filaments and for transporting the filaments away in the machine direction (MD). The invention also relates to a corresponding method for producing spunbonded nonwovens from continuous filaments. - Spunbond nonwoven in the context of the invention means in particular a spunbond nonwoven produced by the spunbond process. Corresponding spunbond devices for producing spunbond nonwovens are known to the person skilled in the art. Because of their quasi-endless length, continuous filaments differ from staple fibers, which have significantly shorter lengths of, for example, 10 mm to 60 mm.

Machine direction (MD) means here and below the direction in which the filament deposit or fleece deposit is transported away by means of a depositing device, in particular by means of a depositing screen belt. In known spunbond devices, the cooling chamber and the stretching device generally extend transversely to the machine direction (MD) and thus in the so-called CD direction. The walls of the cooling chamber and the stretching device facing the filament stream are normally significantly longer in the CD direction than on their end faces or end walls in the MD direction. The cooling air supply in the cooling chamber usually takes place via the long walls - facing the filament flow - in the CD direction (CD walls). Devices and methods of the type described are known in principle in different embodiments from practice. Many of these known devices and methods have the disadvantage that the spunbonded nonwovens produced therewith are not always sufficiently homogeneous or uniform over their surface area. The spunbonded nonwovens produced frequently have disruptive inhomogeneities in the form of flaws or defects. Such inhomogeneities can be observed especially in the edge area of the filament deposit. These deficiencies are apparently due to instabilities in the filament guidance in the edge area. This results in thinned and highly irregular filament deposits in this edge area. Unsteady filament movements in the edge area also lead to mutual contact between the filaments, which can lead to thread breaks. In the case of such a thread break, the beginning of the following new filament is visible in the filament storage, since the thread part was not subjected to the same speed and is therefore significantly thicker than the surrounding filaments in the filament storage. Often the thread part has also not cooled down sufficiently and can therefore stick to the deposit or the screen belt. Mutual filament contact also creates so-called "drops" in the edge area of the fleece deposit, which cause serious disturbances. The drops are created by touching several filaments, which become visible as a mass accumulation on the deposit or on the depositing screen belt. This results in adhesions in the nonwoven deposit, which may adhere to the deposit or also to the rollers in contact with the nonwoven deposit. These flaws are torn out when the fleece is transferred to a calender, which creates undesirable holes in the spunbonded fleece. For these reasons, the edge area or in the area of the MD sides of the fleece tray needs to be improved.

Accordingly, the invention is based on the technical problem of specifying a device of the type mentioned at the beginning with which inhomogeneities or defects in the filament deposit in the edge area or in the MD area can be prevented or at least largely minimized. The invention is also based on the technical problem of specifying a corresponding method for producing such spunbonded nonwovens.

To solve this technical problem, the invention teaches a device for the production of spunbonded nonwovens from continuous filaments, in particular from continuous filaments made of thermoplastic material, a spinnerette being provided for spinning the continuous filaments and a cooling chamber for cooling the spun filaments with cooling air, with a drawing device for drawing the filaments and a depositing device for depositing the filaments and for transporting the filaments away in the machine direction (MD) is available,

wherein the cooling chamber on its opposite sides extending transversely to the machine direction (in the CD direction) each has an air supply cabin for the supply of cooling air and wherein on at least one of the sides (MD sides) arranged parallel to the machine direction (in the MD direction) the Cooling chamber cooling air can be removed from the cooling chamber.

According to the invention, cooling air or process air is therefore discharged from the cooling chamber on the - generally short or shorter - sides (MD sides) or end faces of the cooling chamber. It is within the scope of the invention that cooling air is discharged from the cooling chamber on both of the sides (MD sides) of the cooling chamber that are arranged parallel to the machine direction (in the MD direction). - The air is expediently discharged over the height or the vertical height of an MD side of the cooling chamber and preferably over the entire height or over the entire vertical height of an MD side of the cooling chamber or on several over the height or the vertical height of an MD side of the Cooling chamber distributed points or discharge points.

In this respect, the invention is initially based on the knowledge that to improve the homogeneity of the fleece deposit in the edge areas or in the area of the MD sides of the device, influencing the cooling air flow in these edge areas is sensible and expedient. The filament movements can be influenced in such a way that the filament deposition is uniform. It is also assumed that the air discharge according to the invention on the MD sides effectively prevents the air flow from becoming detached when the cross section is enlarged in the CD direction, so that uniform filament guidance can be maintained. The invention is also based on the knowledge that discharging the cooling air at the end faces or MD sides represents a relatively simple measure with which the technical problem can nonetheless be solved efficiently and functionally. Furthermore, the invention is based on the knowledge that any front-side air suction in the area of a monomer suction between the spinnerette and the cooling chamber or in the area of the stretching device and / or in the area of the diffuser does not provide a remedy here but that it actually affects the cooling air discharge in the area or in the height area of the Cooling chamber arrives. It is of particular importance that the measures according to the invention of the frontal cooling air discharge have proven themselves especially at high throughputs of more than 150 kg / h / m, more than 200 kg / h / m and even more than 250 kg / h / m. In the production of filaments from polyolefins, in particular from polypropylene, the measures according to the invention have proven effective at thread speeds greater than 2000 m / min proven. In the production of filaments from polyester, in particular from polyethylene terephthalate (PET), the measures according to the invention have proven themselves at high thread speeds of 4000 to 5000 m / min or even more than 5000 m / min.

A particularly preferred embodiment of the invention is characterized in that the device according to the invention is set up with the proviso that a continuous discharge or an essentially continuous discharge of the cooling air takes place on at least one MD side, preferably on both MD sides.

It is recommended that at least one, preferably both of the MD sides of the cooling chamber, which are arranged parallel to the machine direction, are delimited or closed by at least one side wall and / or by at least one side door. The cooling air is then discharged in the area of the side wall and / or side door or through the side wall and / or through the side door. It is within the scope of the invention that a side wall or a side door has transparent areas through which the thread position or through which the filament movement can be inspected from the outside.

According to the recommended embodiment of the invention, at least one opening or a plurality of openings is provided in at least one side wall and / or in at least one side door of the MD sides, with at least one opening or through these openings cooling air over the MD sides the cooling chamber is discharged. A preferred embodiment of the invention is characterized in that at least one permeable or semipermeable area or a plurality of permeable or semipermeable areas is provided in at least one side wall and / or in at least one side door of the MD sides, with these permeable or semi-permeable areas cooling air is discharged from the cooling chamber via the MD sides. A particularly proven embodiment of the invention is characterized in that openings and / or permeable or semipermeable areas are arranged distributed over the height of at least one side wall and / or over the height of at least one side door and preferably over the height of both side walls or both side doors . If openings are provided in a side wall and / or a side door, these are expediently at least 5, preferably at least 10 and particularly preferably at least 15 openings. The openings can be implemented in the form of bores, gaps and the like. According to a very preferred embodiment of the invention, the embodiments described above are implemented with the openings and / or with the permeable or semipermeable areas on both MD sides or on both side walls or side doors of the cooling chamber.

According to a highly recommended embodiment of the invention, at least one side door, preferably both side doors, is made into permeable or semi-permeable areas and / or openings are made in the edge profiles.

A well-proven embodiment of the invention is characterized in that at least one MD side, preferably both MD sides, has at least one air guide element, preferably several air guide elements for guiding the cooling air to be discharged. A recommended embodiment of the invention is characterized in that the edge profiles of at least one side door, preferably both side doors, are designed as air guiding elements.

It is within the scope of the invention that there is a pressure gradient or a sufficient pressure gradient in the area of the MD pages so that Cooling air can flow out of the MD sides. A preferred embodiment of the invention is characterized in that the cooling air is discharged from the cooling chamber passively via the MD sides of the cooling chamber. In this case, the device is set up with the proviso that cooling air can be discharged through at least one MD side, preferably through both MD sides, of the cooling chamber due to an overpressure in the cooling chamber. Furthermore, a preferred embodiment of the invention is characterized in that cooling air is actively discharged from the cooling chamber via at least one MD side. In this preferred embodiment variant, at least one fan is provided with which cooling air can be removed from the cooling chamber through at least the MD side of the cooling chamber.

It is within the scope of the invention that the device according to the invention is designed with the proviso that on one MD side of the cooling chamber, preferably on each of the two MD sides of the cooling chamber, a cooling air quantity of 1 to 400 m ³ / h, preferably 2 up to 350 m ³ / h and in particular from 5 to 350 m ³ / h can be removed. A cooling air quantity of 10 to 300 m ³ / h, in particular 25 to 250 m ³ / h and very preferably 30 to 200 m ³ / h is particularly preferred on one MD side or on each of the two MD sides of the cooling chamber deductible.

It is also within the scope of the invention that a regulation or throttling of the discharged cooling air volume flow takes place as a function of the thread position or the filament arrangement and / or filament movement in the area of the MD sides. In this way, the thread position or the filament movement in the area of the MD sides can be observed and the regulation or throttling of the cooling air volume flow is adjusted until the filament bundle no longer shows any undesired movements. The observation can in particular through transparent areas in the side doors of the device. Appropriately, the discharged cooling air volume flows on the two MD sides can be regulated or throttled separately.

According to a particularly preferred embodiment of the invention, there is a semi-automatic or automatic control or throttling of the cooling air volume flow discharged on the MD sides. In this respect, it is within the scope of the invention that the cooling air volume flow discharged on at least one MD side, preferably on both MD sides, is regulated or throttled as a function of at least one measurement parameter. According to one embodiment, the pressure in the cooling chamber can be regulated or throttled as a function of at least one measurement parameter, and the pressure or overpressure in the cooling chamber then takes place - as it were a passive - a cooling air volume flow, expediently against a fixed throttling . One embodiment variant is characterized in that, depending on at least one measurement parameter, at least one suction fan is set to discharge the cooling air volume flow on at least one MD side, preferably on both MD sides (active cooling air discharge). The at least one measurement parameter is in particular the throughput of the device and / or the selected plastic for the filaments and / or the melt temperature and / or the air temperature and / or the volume flow in the cooling chamber and / or the pressure in the cooling chamber. Depending on the measured parameter, the above-described regulation or throttling of the cooling air volume flow that is discharged via the MD side or the MD sides of the cooling chamber then takes place.

A recommended regulation or throttling of the discharged cooling air volume flow is characterized in that the filaments or the filament movement in the edge area on the MD sides are recorded with the aid of a camera or the like. The required cooling air volume flow to be discharged can be calculated, adjusted and regulated either as a function of the filament movement or as a function of a brightness distribution with appropriate lighting. Corresponding camera images or camera evaluations can also be displayed on a control panel, so that control or regulation of the discharged cooling air volume flow is possible from there. Another embodiment of the invention is characterized in that the fleece deposit is observed or measured and evaluated in the edge area on the MD sides and the required cooling air volume flow to be discharged is set or regulated as a function of the evaluation results. - It is within the scope of the invention that the device according to the invention has at least one control and / or regulating device with which the cooling air volume flow discharged through the at least one MD side or through the MD sides can be controlled and / or regulated or can be throttled.

According to one embodiment of the invention, the cooling air volume flows discharged via the two MD sides can be the same or essentially the same. However, it is also within the scope of the invention that cooling air volume flows of different sizes are discharged on the two MD sides. A further embodiment of the invention is characterized in that a different cooling air discharge takes place over the height or the vertical height of the cooling chamber or different cooling air volume flows are discharged. In this respect, different blow-off profiles result over the height or over the vertical height of the cooling chamber in this embodiment.

A recommended embodiment of a spunbond device used within the scope of the invention is described below. - According to the invention, the continuous filaments are spun by means of a spinnerette and fed to the cooling chamber for cooling the filaments with cooling air. - It is within the scope of the invention that at least one spinning beam for spinning the filaments is arranged transversely to the machine direction (MD direction). According to a very preferred embodiment of the invention, the spinning beam is oriented perpendicular or essentially perpendicular to the machine direction. However, within the scope of the invention it is also possible for the spinning beam to be arranged at an angle to the machine direction. - A preferred embodiment of the invention is characterized in that at least one monomer suction device is arranged between the spinnerette and the cooling chamber. With this monomer suction device, air is sucked out of the filament formation space below the spinnerette. In this way, the gases such as monomers, oligomers, decomposition products and the like that emerge in addition to the continuous filaments can be removed from the device. A monomer suction device preferably has at least one suction chamber to which at least one suction fan is expediently connected. It is within the scope of the invention that, in the direction of flow of the filaments, the cooling chamber with the air supply cabins for supplying the cooling air is connected to the monomer suction device. The cooling air is introduced into the cooling chamber from these air supply booths extending in the CD direction (transverse to the machine direction). The removal of cooling air according to the invention from the cooling chamber via the MD sides of the cooling chamber takes place parallel to the machine direction and thus in the MD direction. These MD sides of the cooling chamber are expediently shorter or significantly shorter than the CD sides of the cooling chamber, along which the two opposing air supply cabins of the cooling chamber extend.

According to a preferred embodiment of the invention, the air supply cabins can each be subdivided into two or more cabin sections arranged one above the other, from which cooling air of different temperatures can preferably be supplied. It is recommended that cooling air at a temperature T _{1 is introduced} into the cooling chamber via two opposite cabin sections of the air supply cabins and cooling air at a temperature T _{2 is} introduced into the cooling chamber via two opposing cabin sections of the two air supply cabins arranged below, the two temperatures T ₁ and T being mutually exclusive ₂ appropriately differentiate. It is within the scope of the invention that cooling air discharge according to the invention takes place on the MD sides in the area of each cabin section of the supply cabin.

It is within the scope of the invention that the filaments are introduced from the cooling chamber into a stretching device for stretching the filaments. Appropriately, the cooling chamber is followed by an intermediate channel which connects the cooling chamber with a stretching shaft of the stretching device. A particularly preferred embodiment of the invention is characterized in that the unit from the cooling chamber and the stretching device or the unit from the cooling chamber, the intermediate channel and the stretching shaft is designed as a closed system. In this context, closed system means in particular that, apart from the supply of cooling air into the cooling chamber, no further air supply takes place in this unit. The discharge of the cooling air according to the invention on the MD sides of the cooling chamber has proven particularly useful in combination with the preferred closed unit with a view to solving the technical problem. Especially with this combination, the Filament deposit achieved particularly homogeneous and defect-free fleece sections. This is especially true if the cooling air is discharged on the MD sides of the cooling chamber at points distributed over the height of the MD sides and especially when cooling air is discharged both in the upper half of the MD sides and in the lower half of the MD -Sides of the cooling chamber is carried out.

According to a recommended embodiment of the invention, at least one diffuser, through which the filaments are guided, adjoins the stretching device in the direction of flow of the filaments. This diffuser expediently comprises a diffuser cross section that widens in the direction of the filament deposit or a divergent diffuser section. It is within the scope of the invention that the filaments are deposited on a depositing device for filament depositing or for depositing fleece. The depositing device is expediently a depositing screen belt or an air-permeable depositing screen belt. With this depositing device or with this depositing screen belt, the nonwoven web formed from the filaments is transported away in the machine direction (MD). It is recommended that process air is sucked through the depositing device or through the depositing screen belt or is sucked from below through the depositing screen belt in the deposit area of the filaments. A particularly stable filament deposit or fleece deposit can thereby be achieved. This suction is also of particular importance in combination with the cooling air discharge according to the invention on the MD sides of the cooling chamber. After being deposited on the depositing device, the filament deposit or the nonwoven web is expediently fed to further treatment measures, in particular calendering.

A highly recommended embodiment of the invention is characterized in that a flow straightener is provided on the cooling chamber side in at least one air supply cabin, preferably in both air supply cabins of the cooling chamber, through which the cooling air flows before it enters the cooling chamber. The flow straighteners serve to straighten the cooling air flow hitting the filaments. It is within the scope of the invention that a flow straightener has a plurality of flow channels oriented perpendicular to the filament flow. These flow channels are expediently each delimited by channel walls and are preferably linear. It has been proven that the freely permeable open area of each flow straightener is more than 90% of the total area of the flow straightener. Free flow through open surface of the flow straightener means the surface through which the cooling air can flow freely and is not blocked by the channel walls or by spacers possibly arranged between the flow channels. The ratio of the length L of the flow channels to the smallest inner diameter D _{i of} the flow channels is preferably in the range between 1 and 10, expediently in the range between 1 and 9. The flow channels can, for example, have a polygonal cross section, in particular a hexagonal cross section. However, they can also be round, for example circular, in cross section. The term "smallest inside diameter D _i " refers here and below to the smallest inside diameter measured in a flow channel of the flow straightener if this flow channel has different inside diameters with regard to its cross section. The smallest inside diameter D _i, for a cross section in the form of a regular hexagon, is measured between two opposite sides and not between two opposite corners. When the smallest Inside diameter varies in the various flow channels, the smallest inside diameter D _{i means} in particular the smallest inside diameter averaged with respect to the plurality of flow channels or the mean smallest inside diameter.

According to one embodiment of the invention, the cooling air discharged from at least one MD side, preferably from both MD sides of the cooling chamber, can be introduced into the monomer suction device. For this purpose, the at least one suction fan connected to the monomer suction device can be used. In this embodiment, the discharged cooling air is preferably passed through a filter system provided in the monomer suction device. Alternatively or additionally, the cooling air discharged on an MD side or on the MD sides of the cooling chamber can be introduced into the intermediate channel and / or into the diffuser and / or into the suction below the storage device. By means of these discharges, in each case or in combination, a sufficient pressure gradient for discharging the cooling air from the cooling chamber can be generated.

To solve the technical problem, the invention also teaches a method for the production of spunbonded nonwovens from continuous filaments, in particular from continuous filaments made of thermoplastic material, the continuous filaments being spun out and then being cooled in a cooling chamber, with the filaments being cooled across two opposite one another to the machine direction (in the CD direction) extending sides cooling air is introduced into the cooling chamber and cooling air is discharged from the cooling chamber on at least one of the sides (MD sides) arranged parallel to the machine direction - preferably on both MD sides.

It has already been pointed out that, according to the recommended embodiment, the cooling air volume flow discharged through the at least one MD side, preferably the cooling air volume flow discharged through both MD sides, is controlled and / or regulated or throttled. The cooling air volume flow discharged through the at least one MD side - preferably through both MD sides - is expediently regulated or controlled depending on the filament state or the filament bundle state in the area of the MD side or in the area of the MD sides. throttled. It is also within the scope of the invention that the cooling air volume flows discharged through the two MD sides can each be controlled and / or regulated or throttled separately. As part of the method according to the invention, the cooling air discharged through at least one MD side - preferably through both MD sides of the cooling chamber - can be fed into a monomer suction device provided between the spinnerette and the cooling chamber and / or into the process volume flow below the cooling chamber and / or into the stretching device and / or into a diffuser arranged between the stretching device and the depositing device and / or into the suction below the depositing device.

A recommended embodiment of the invention is characterized in that throughputs of over 150, preferably over 200 kg / h / m and also over 250 kg / h / m are used. The throughputs achieved in the process according to the invention are expediently 150 to 300 kg / h / m. It is within the scope of the invention that in the process according to the invention in the course of producing filaments or spunbonded nonwovens from polyolefins, in particular from polypropylene, a thread speed or a filament speed of more than 2000 m / min is used. It is also within the scope of the invention that in the process according to the invention in the course of the production of filaments or spunbonded nonwovens from polyester, in particular from polyethylene terephthalate (PET), is worked with a thread speed or with a filament speed of more than 4000 m / min, in particular of more than 5000 m / min. The measures according to the invention have also proven themselves especially with the aforementioned high throughputs and high thread speeds. Here, too, very stable, compact and homogeneous edge deposits of the nonwovens can be obtained.

The invention is based on the knowledge that spunbonded nonwovens of optimal quality and very homogeneous properties can be produced with the device according to the invention and with the method according to the invention. In contrast to many measures known from practice and from the prior art, homogeneous fleece sections that have virtually no flaws are possible, especially in the edge areas (on the MD sides) of the filament deposit. The web deposits produced according to the invention have a uniform or essentially uniform weight per unit area over their width - and in particular also in their edge regions. The fact that a preferred flow direction is imposed on the air or cooling air in the MD areas, as it were, means that a very stable, compact and uniform edge area can be achieved. The device according to the invention and the method according to the invention are also suitable for high filament speeds and high throughputs. Here, too, excellent homogeneous properties of the nonwoven web can be achieved over the entire width of the nonwoven web and thus also in the edge areas. Due to the cooling air discharge according to the invention in the area of the MD sides of the cooling chamber, there is a very positive influence on the filament flow and any adjustments to be made to the cooling air volume flow to be discharged are possible in a simple and inexpensive manner. Above all, it should be emphasized that the drops that can be observed in many known measures are prevented in the edge regions of the nonwoven web can or can at least largely be minimized. It should also be emphasized that the advantages mentioned can be achieved through relatively simple measures and through a low-cost apparatus structure of the device. In comparison to the previously known spunbond devices, hardly any or only little additional hardware is required here to implement the measures according to the invention. This applies above all to passive cooling air removal via the overpressure in the cooling chamber. It should also be emphasized that the invention can be adjusted to different working widths of the nonwoven web deposit in a simple and inexpensive manner.

Fig. 1

einen Vertikalschnitt durch die erfindungsgemäße Vorrichtung,

Fig. 2

eine Ansicht des Schnittes A-A durch den Gegenstand der Fig. 1,

Fig. 3

eine Draufsicht auf einen Querschnitt B-B durch den Gegenstand der Fig. 1,

Fig. 4

eine perspektivische Ansicht von Luftleitelementen an einer MD-Seite der erfindungsgemäßen Vorrichtung,

Fig. 5

eine perspektivische Ansicht eines Aggregates aus einem Strömungsgleichrichter mit vor- und nachgeschaltetem Strömungssieb und

Fig. 6

einen Querschnitt durch einen Strömungsgleichrichterabschnitt.

The invention is explained in more detail below with reference to a drawing showing only one embodiment. It shows in a schematic representation:

Fig. 1

a vertical section through the device according to the invention,

Fig. 2

a view of the section AA through the subject of FIG Fig. 1 ,

Fig. 3

a plan view of a cross section BB through the subject of FIG Fig. 1 ,

Fig. 4

a perspective view of air guide elements on an MD side of the device according to the invention,

Fig. 5

a perspective view of an assembly of a flow straightener with upstream and downstream flow screen and

Fig. 6

a cross section through a flow straightener section.

The figures show a device according to the invention for producing spunbonded nonwovens from continuous filaments 1, in particular from continuous filaments 1 made of thermoplastic material. The device has a spinnerette 2 for spinning the continuous filaments 1. These spun continuous filaments 1 are introduced into a cooling device 3 with a cooling chamber 4 and with air supply cabins 5, 6 arranged on two opposite sides of the cooling chamber 4. The cooling chamber 4 and the air supply cabins 5, 6 extend transversely to the machine direction MD and thus in the CD direction of the device. Cooling air is introduced into the cooling chamber 4 from the opposite air supply cabins 5, 6. In each of the two air supply cabins 5, 6, a flow straightener 18 is expediently provided on the cooling chamber side in the exemplary embodiment, through which the cooling air flows before it enters the cooling chamber 4.

A monomer suction device 7 is preferably arranged between the spinnerette 2 and the cooling device 3 in the exemplary embodiment. With this monomer suction device 7 interfering gases occurring during the spinning process can be removed from the device. These gases can be, for example, monomers, oligomers or decomposition products and similar substances. The monomer suction device 7 expediently and in the exemplary embodiment has a suction fan 22 for suctioning off the interfering gases.

The air supply cabins 5, 6 with their flow straighteners 18 extend along the CD sides 24 of the cooling chamber 4 transversely to the machine direction MD. Cooling air is supplied to the cooling chamber 4 from the air supply cabins 5, 6 through the CD sides. According to the invention, on the front sides or on the MD sides 25 of the cooling chamber cooling air is discharged. These cooling air flows are particularly in the Fig. 3 and illustrated there by arrows. The cooling air discharge on the MD sides 25 is explained in more detail below. The end faces or the MD sides 25 of the cooling chamber 4 are expediently and in the exemplary embodiment the short sides of the cooling chamber 4, which are in particular made significantly shorter than the CD sides 24. According to an embodiment variant and in the exemplary embodiment, are on the MD sides 25 of the cooling chamber 4 side doors 23 are provided.

In the filament flow direction FS, the cooling device 3 is followed by a stretching device 8 in which the filaments 1 are stretched. The stretching device 8 preferably and in the exemplary embodiment has an intermediate channel 9 which connects the cooling device 3 to a stretching shaft 10 of the stretching device 8. According to a particularly preferred embodiment and in the exemplary embodiment, the unit from the cooling device 3 and the stretching device 8 or the unit from the cooling device 3, the intermediate channel 9 and the stretching shaft 10 is designed as a closed system. In this context, a closed system means, in particular, that apart from the supply of cooling air in the cooling device 3, no further air is supplied to this unit. This closed system has proven particularly useful in connection with the cooling air discharge according to the invention on the MD sides 25 of the device.

Preferably and in the exemplary embodiment, a diffuser 11, through which the filaments 1 are guided, adjoins the stretching device 8 in the filament flow direction FS. According to a recommended embodiment and in the exemplary embodiment, secondary air inlet gaps 12 for introducing secondary air into the diffuser 11 are between the stretching device 8 or between the stretching shaft 10 and the diffuser 11 intended. After passing through the diffuser 11, the filaments are preferably and in the exemplary embodiment deposited on a depositing device designed as a depositing screen belt 13. The filament deposit or the nonwoven web 14 is then conveyed or transported away with the depositing screen belt 13 in the machine direction MD. Appropriately and in the exemplary embodiment, a suction device for sucking air or process air through the depositing screen belt 13 is provided under the depositing device or below the depositing screen belt 13. For this purpose, a suction area 15 is preferred and arranged in the exemplary embodiment below the diffuser outlet under the screen belt 13. The suction area 15 preferably extends at least over the width B of the diffuser outlet. Recommended and in the exemplary embodiment, the width b of the suction area 15 is greater than the width B of the diffuser outlet.

According to the preferred embodiment and in the exemplary embodiment, each air supply cabin 5, 6 is divided into two cabin sections 16, 17, from which cooling air of different temperatures can be introduced into the cooling chamber 4. In the exemplary embodiment may from the upper cabin sections 16 each cooling air having a temperature T to be supplied to _1, whereas from the two lower portions 17 each cabin cooling air a direction different from the temperature T ₁ Temperature T can be fed to _{the second} The air supply cabins 5, 6 can also be divided into more than two cabin sections 16, 17 arranged one above the other, from which cooling air of different temperatures is expediently supplied. This subdivision of the air supply cabins 5, 6 and the inflow of cooling air at different temperatures is also of particular importance in combination with the cooling air discharge according to the invention via the MD sides 25. In this embodiment, very homogeneous edge sections of the fleece deposit are created achieved and a very stable and compact edge of the nonwoven web 14 is achieved.

especially the Fig. 2, 3 and 4th illustrate the cooling air discharge according to the invention via the MD sides 25 of the cooling chamber 4. The cooling air volume flows are discharged here transversely to the machine direction MD and thus in the CD direction or essentially in the CD direction. The directions of the flow vectors correspond to the arrows symbolizing the cooling air flows in the figures. Due to the measures according to the invention, the cooling air is given a preferred flow direction (in the CD direction) in the edge area, which causes the advantages according to the invention.

According to one embodiment of the invention, the cooling air volume flows discharged on the two MD sides 25 of the cooling chamber 4 can be set differently. As a result, disruptive manufacturing and assembly tolerances and / or different process air volume flows or monomer volume flows can be compensated for with regard to a homogeneous fleece deposit. Incidentally, differences between the two edges of the fleece deposit due to unevenness due to different heat input by the plastic melt or due to different per-hole throughputs on the spinnerette or due to different mixing ratios can be compensated for.

The Fig. 4 shows a preferred example of an embodiment of an MD side 25 of the cooling chamber 4 for the purpose of a cooling air discharge according to the invention. Here, on the MD sides 25, angular air guide elements 26 extending over the height of the cooling chamber 4 are provided. In the exemplary embodiment, these air guiding elements 26 form the edge profiles of the side doors 23. These air guiding elements 26 have bores 27 which are arranged distributed over the height of the cooling chamber 4. The cooling air is discharged on the MD sides via these bores 27 of the air guide elements 26. This discharge can take place passively due to an overpressure in the cooling chamber 4 and / or actively by actively sucking off the cooling air, for example by means of a fan not shown in the figures. Preferably, and in the exemplary embodiment, the cooling air is discharged over the entire height of the cooling chamber 4. It is within the scope of the invention that the cooling air flows drawn off through the bores 27 are brought together in a line and / or in a chamber and are controlled, for example, via a slide . One embodiment is characterized in that the partial volume flows of cooling air withdrawn from both MD sides 25 of the cooling chamber 4 are brought together - for example are brought together in a chamber and / or a line - and set together - in particular with an actuating and / or regulating element or regulated.

The combination of the cooling air discharge on the MD sides 25 of the cooling chamber 4 with the flow straighteners 18 arranged in the air supply cabins 5, 6 of the cooling chamber 4 is of particular importance according to the invention. The flow straighteners 18 preferably extend and in the exemplary embodiment over both cabin sections 16, 17 of each air supply cabin 5, 6. The flow straighteners 18 serve to straighten the cooling air flow impinging on the filaments 1. The Fig. 5 shows a perspective view of a flow straightener 18 which is preferably used within the scope of the invention. This flow straightener 18 has, as recommended and in the exemplary embodiment, a plurality of flow channels 19 oriented perpendicular to the filament flow FS. This Flow channels 19 are expediently each delimited by channel walls 20 and are preferably linear.

According to the preferred embodiment and in the exemplary embodiment, the freely permeable open area of each flow straightener 18 is more than 90% of the total area of the flow straightener 18. Proven and in the exemplary embodiment, the ratio of the length L of the flow channels 19 to the smallest inner diameter D _{i of} the flow channels 19 is in the range between 1 and 10, expediently in the range between 1 and 9. The flow channels 19 of a flow straightener 18 can, for example and in the exemplary embodiment according to Fig. 6 have a hexagonal or honeycomb cross-section. The smallest inside diameter D _i is measured here between opposite sides of the hexagon.

Recommended and in the exemplary embodiment, each flow straightener 18 has a flow screen 21 both on its cooling air inflow side ES and on its cooling air outflow side AS. Preferably, and in the exemplary embodiment, the two flow screens 21 of each flow straightener 18 are arranged directly in front of or behind the flow straightener 18. Recommended and in the exemplary embodiment, the two flow screens 21 of a flow straightener 18 or the surfaces of these flow screens 21 are oriented perpendicular to the longitudinal direction of the flow channels 19 of the flow straightener 18. It has been proven that a flow screen 21 has a mesh size of 0.1 to 0.5 mm and preferably 0.1 to 04 mm and a wire thickness of 0.05 to 035 mm and preferably 0.05 to 0.32 mm. - It was shown above that, according to a preferred embodiment, the freely permeable open area of each flow straightener 18 is more than 90% of the total area of the Flow straightener 18 is. The flow screens are not included in this calculation of the freely permeable open area of the flow straightener 18.

Claims (18)

1. A device for producing spunbonded non-wovens from continuous filaments (1), particularly from continuous filaments (1) made from a thermoplastic plastic, wherein a spinneret (2) is provided for spinning the continuous filaments (1) and a cooling chamber (4) for cooling the spun filaments (1) using cooling air, wherein furthermore, a stretching device (8) is present for stretching the filaments (1) and a depositing device is present for depositing the filaments (1) and for transporting the filaments in the machine direction (MD),
   wherein the cooling chamber (4) has an air supply booth (5, 6) for supplying cooling air in each case on its opposite sides extending transversely to the machine direction (in CD direction) and wherein cooling air can be removed from the cooling chamber (4) on at least one of the sides (MD sides), arranged parallel to the machine direction (in MD direction), of the cooling chamber (4).
2. The device according to Claim 1, wherein cooling air can be removed or is removed from the cooling chamber (4) on both MD sides (25) of the cooling chamber (4) arranged parallel to the machine direction (in MD direction).
3. The device according to one of Claims 1 or 2, wherein at least one, preferably both of the MD sides (25) of the cooling chamber (4) arranged parallel to the machine direction (in MD direction) is/are delimited by in each case at least one side wall and/or by in each case at least one side door (23).
4. The device according to Claim 3, wherein at least one opening and/or at least one permeable or semipermeable region is provided in a side wall and/or in a side door (23), wherein cooling air can be removed or is removed from the cooling chamber (4) through this at least one opening and/or through this at least one permeable or semipermeable region.
5. The device according to Claim 4, wherein a plurality of openings, preferably at least five, preferably at least ten and particularly preferably at least 15 openings are arranged in a side wall and/or in a side door (23) and/or wherein a plurality of permeable or semipermeable regions is provided in a side wall and/or in a side door.
6. The device according to one of Claims 1 to 5, wherein the device is set up with the requirement that cooling air can be removed or is removed through at least one MD side (25) of the cooling chamber (4) owing to an overpressure in the cooling chamber (4).
7. The device according to one of Claims 1 to 6, wherein at least one fan is provided, using which cooling air can be removed or is removed from the cooling chamber (4) through at least one MD side (25) of the cooling chamber (4).
8. The device according to one of Claims 1 to 7, wherein the device is designed with the requirement that on an MD side (25) of the cooling chamber (4), preferably on each of the two MD sides of the cooling chamber (4), 1 to 400m³/h, preferably 2 to 300 m³/h, particularly preferably 10 to 300 m³/h and very preferably 30 to 200 m³/h of cooling air can be removed.
9. The device according to one of Claims 1 to 8, wherein at least one MD side (25), preferably both MD sides (25), has/have at least one air conduction element (26), preferably a plurality of air conduction elements (26) for guiding the cooling air to be removed.
10. The device according to Claim 9, wherein at least one side door (23) delimiting an MD side (25) has at least one air conduction element (26), preferably has a plurality of air conduction elements (26), wherein the edge profiles of a side door (23) are preferably constructed as air conduction elements (26).
11. The device according to one of Claims 1 to 10, wherein at least one open- and/or closed-loop control device is provided, using which the volumetric flow of the cooling air removed through the at least one MD side (25) or through the MD sides (25) can be controlled in an open- and/or closed-loop manner or throttled.
12. The device according to one of Claims 1 to 11, wherein a monomer suction device (7) is arranged between the spinneret (2) and the cooling chamber (4) and wherein the cooling air removed from at least one MD side (25) of the cooling chamber (4) can be introduced into the monomer suction device (7), wherein the removed cooling air can preferably be guided through a filter system provided in the monomer suction device (7).
13. A method for producing spunbonded non-wovens from continuous filaments (1), particularly from continuous filaments (1) from a thermoplastic plastic - particularly by means of a device according to one of Claims 1 to 12 - wherein the continuous filaments (1) are spun and are cooled in a cooling chamber (4) subsequently thereto, wherein cooling air is introduced into the cooling chamber (4) for cooling the filaments (1) by means of two opposite sides extending transversely to the machine direction, and wherein cooling air is removed on at least one of the sides (MD sides) arranged parallel to the machine direction - preferably on both MD sides (25) - of the cooling chamber.
14. The method according to Claim 13, wherein cooling air is removed on both sides arranged parallel to the machine direction or on both MD sides (25).
15. The method according to one of Claims 13 or 14, wherein the volumetric flow of cooling air removed through at least one MD side (25), preferably through both MD sides (25), is controlled in an open-loop and/or closed-loop manner or throttled.
16. The method according to one of Claims 13 to 15, wherein the volumetric flow of cooling air removed through at least one MD side (25), preferably through both MD sides (25) is controlled in a closed-loop manner or throttled as a function of the filament or filament-bundle state in the region of the MD side (25) or the MD sides (25).
17. The method according to one of Claims 13 to 16, wherein the volumetric flows of cooling air removed by the two MD sides (25) are in each case separately controlled in an open-loop and/or closed-loop manner or throttled.
18. The method according to one of Claims 13 to 17, wherein the cooling air removed through at least one MD side (25), preferably through both MD sides (25) is introduced into a monomer suction device (7) provided between spinneret (2) and cooling chamber (4) and/or into the stretching device (8) and/or into a diffuser (11) arranged between stretching device (8) and depositing device.

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