EP3199672B1 - 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 of thermoplastic material, wherein a Spinnerette for spinning the filaments and a cooling device for cooling the filaments is provided and wherein between Spinnerette and cooling device at least one Monomerabsaugungsvorrichtung for suction of the spinning process Gas is arranged. The invention further relates to a process for the production of spunbonded nonwovens from continuous filaments. - Endless filaments are known to differ because of their quasi-endless length of staple fibers, which have much smaller lengths, for example, 10 to 60 mm. - With the Monomerabsaugungsvorrichtung air or gas is sucked from the Filamentbildungsraum directly below the spinnerette. This ensures that the gases exiting in addition to the polymer filaments in the form of monomers, oligomers, decomposition products and the like from the filament formation space or from the device can be at least partially removed.

Out EP 1 340 843 A1 an apparatus for producing spunbonded nonwovens of the type mentioned above is known. The spunbonded nonwovens are produced from continuous filaments of thermoplastic material. There is provided a spinnerette for spinning the filaments and cooling means for cooling the filaments. Furthermore, a monomer suction device is arranged between the spinnerette and the cooling device for the suction of gases generated during the spinning process. The Monomerabsaugungsvorrichtung has two arranged in the machine direction one behind the other, each transverse to Machine direction extending and with respect to the spinning field opposite CD-suction opening areas. Each of the two opposing CD extraction port areas has two suction gaps. - Out US 2003/178741 A1 a similar device is known.

Devices of the type mentioned are basically known in practice in various embodiments. In these devices, the filaments are spun by means of a spinnerette, then cooled in a cooling device and then passed through a drawing unit and finally deposited on a tray to spunbonded. Such a device is also referred to as a spunbond device. Many of these known devices have the disadvantage that the filaments often can not be stored correctly to the spunbonded fabric. Filament deposition results in irregularities in the form of defects or defects in the spunbonded nonwoven. The homogeneity of the spunbonded nonwovens is more or less affected by these defects or disturbances. One cause of the defects in the spunbonded fabric are so-called drops, which result from the tearing off of one or more filaments and the formation of melt accumulations. These drops create imperfections or thick spots in the spunbonded fabric and / or stick to the support for the spunbonded nonwoven. In general, such drops or flaws are larger than 2 x 2 mm. Defects in the spunbonded fabric also result from so-called "hard pieces", which result as follows: By loss of tension, a spun filament can relax, snap back and thus form a knot, which sticks together due to the molten state of the filament. As a rule, no demolition of the filament takes place. The resulting defects in the spunbonded fabric usually have sizes smaller than 2 x 2 mm and are usually palpable and / or visible. The invention is based on the finding that such defects or defects in the spunbonded nonwovens occur in particular at higher filament speeds and / or at higher throughputs from 120 kg / h / m and above all from 150 kg / h / m. Such irregularities in the spunbonded webs can be observed above all even with larger spinning field depths.

So far, attempts have been made to reduce the problems described above by, for example, treating the filaments more uniformly in the cooling device or cooling them more uniformly with cooling air. Attempts have also been made to improve the seals of the device in order to achieve a more uniform filament flow or a more uniform filament treatment. These measures have only led to limited success, especially at higher throughputs. Therefore, known from practice devices are in need of improvement.

Accordingly, the technical problem underlying the invention is to provide a device of the type mentioned above, with which spunbonded webs can be produced with a high degree of homogeneity without appreciable defects, even at high filament speeds and / or high throughputs as well as wide or deep spinning fields. Furthermore, the invention is the technical problem of specifying a corresponding method for producing such spunbonded nonwovens.

To solve this technical problem, the invention teaches an apparatus for producing spunbonded nonwovens from continuous filaments, in particular from continuous filaments of thermoplastic material, wherein a spinnerette for spinning the filaments and a cooling device for cooling the Filaments is provided, wherein in the region of the spinnerette, preferably between the spinnerette and the cooling device, at least one monomer suction device is arranged for the suction of gases generated during the spinning process,
wherein the Monomerabsaugungsvorrichtung has at least two in the machine direction (MD) arranged one behind the other, transversely - preferably perpendicular - to the machine direction (CD) extending and with respect to the spinning field opposite CD-suction port areas and wherein the two CD-suction port areas and / or at least two opposite CD-extraction opening portions of the CD extraction opening areas are set up with the proviso that over one of the two CD extraction opening areas and / or CD extraction opening portions, a higher volume of gases is sucked over than the other opposite CD exhaust port area and / or CD exhaust port portion,
such that the ratio of the volume flow V extracted by a CD suction opening area and / or CD suction opening partial area to the volume flow V 6 extracted by the other CD suction opening area and / or CD suction opening area lying opposite to the spinning field : 1 to 1.1: 1, preferably 5.5: 1 to 1.3: 1, preferably 5.5: 1 to 1.5: 1 and more preferably 5: 1 to 1.75: 1.

It is within the scope of the invention that the device according to the invention is a spunbond device for producing spunbond nonwovens, wherein the device comprises a spinnerette, a monomer suction device, a cooling device, an adjoining stretching unit for drawing the filaments and a storage device for filing the filaments to spunbond nonwoven web has.

Machine direction (MD) means in the context of the invention, in particular the conveying direction of the deposited spunbonded web. In general, the spunbonded web is carried away with a conveyor belt or endless conveyor belt. In the context of the invention, the CD direction means, in particular, the direction preferably perpendicular to the direction perpendicular to the conveying direction of the spunbonded web or to the MD direction.

The CD exhaust port portions and the CD exhaust port portions are suitably provided in two opposite side walls extending transversely to the machine direction, which side walls bound the filament forming space below the spinnerette. A CD suction opening area and / or a CD suction opening partial area can be formed either by only one suction opening or one suction gap or by a plurality of suction openings or suction gaps. Thus, a CD extraction opening region and / or a CD extraction partial region may also each be formed by a plurality of extraction bores.

It is within the scope of the invention that the volume flow drawn off in the monomer suction device or the extracted volume flow enters / enters at least one collection chamber and preferably at least one collection tube connected to the collection chamber. Conveniently, for each of two opposite relative to the spinning field CD extraction port areas at least one collection chamber, and preferably at least one to the or each collection chamber connected collecting pipe for receiving the extracted gas provided. It can also be present for each of these pages several collection chambers or multiple manifolds. At least one suction line, preferably in each case a plurality of suction lines for the suction of the gas, is connected to a collecting chamber and it is recommended that the at least one suction line connect the suction lines to the collecting chamber with a collecting tube. Following at least one collecting chamber and expediently in at least one connected suction line, the volume flow can be adjusted by at least one shut-off element, for example by a gate valve with linear guide for setting the open cross section. The setting or throttling takes place within the scope of the invention, with the proviso that a higher volume flow can be extracted via the one of the CD suction opening regions opposite the spinning field than via the other CD suction opening region.

• indem die Öffnungsweiten bzw. die Öffnungsflächen der CD-Absaugungsöffnungs-Bereiche und/oder CD-Absaugungsöffnungs-Teilbereiche entsprechend ausgelegt und/oder entsprechend einstellbar sind
• und/oder indem die Absaugung des Volumenstromes - insbesondere in oder an der zumindest einen Sammelkammer und/oder in bzw. an der Saugleitung/den Saugleitungen zur Absaugung des Gases und/oder in oder an dem zumindest einen Sammelrohr - einstellbar bzw. drosselbar ist.

Basically, in the context of the invention, the suction of a higher volume flow can be realized on one side of the monomer suction or via a CD suction opening area and / or CD suction opening partial area,

• in that the opening widths or the opening areas of the CD extraction opening areas and / or CD extraction opening areas are designed and / or adjusted accordingly
• and / or by the extraction of the volume flow - in particular in or on the at least one collecting chamber and / or in or on the suction line / the Suction lines for suction of the gas and / or in or on the at least one collecting tube - is adjustable or throttled.

It is within the scope of the invention that with respect to the suction of the higher volume flow, a change between the two sides of the Monomerabsaugung or a change between the two CD-Absaugungsöffnungs-areas or CD-Absaugungsöffnungs partial areas can take place. Thus, alternatingly-in particular during continuous operation of the device-first a higher volume flow can be sucked off via the one CD-suction opening area and then over the other CD-suction opening area.

It is within the scope of the invention that the monomer suction device has suction opening areas and preferably has at least two machine direction (MD) arranged one behind the other, each transverse - preferably perpendicular - to the machine direction (CD) extending and with respect to the spinning field opposite CD-suction opening areas , And that the opening area of the suction opening areas - in particular the CD-suction opening areas - over 11,000 mm ² / m, in particular about 12,000 mm ² / m spinning field - measured transversely to the machine direction or CD direction - is or is adjustable , Expediently more than 20,000 mm ² / m spinning field, preferably over 30,000 mm ² / m spinning field, very preferably over 40,000 mm ² / m spinning field and more preferably over 50,000 mm ² / m spinning field is or is adjustable. According to a highly recommended embodiment of the invention, an opening area of the suction opening areas - in particular the CD-suction opening areas - over 60,000 mm ² / m spinning field and preferably over 65,000 mm ² / m spinning field available or adjustable. Appropriately, the Opening area or the adjustable opening area of the suction opening areas - in particular the CD-suction opening areas up to 100,000 mm ² / m spinning field, preferably up to 90,000 mm ² / m spinning field and more preferably up to 85,000 mm ² / m spinning field.

Preferably, the respective opening areas of the CD suction opening areas are designed or adjustable with the proviso that a higher volume flow can be sucked through one of the two opposite CD suction opening areas than through the other CD suction opening area. It is within the scope of the invention that the opening area of a CD-suction opening area is larger or can be set to be larger than the opening area of a second CD-suction opening area opposite to the spinning field. For example, the opening area of a machine direction (MD) rear CD exhaust opening area may be larger or more adjustable than the opening area of a machine front CD exhaust opening area, or vice versa. The opening area of the opposing CD-suction opening areas can also be set to different sizes, so that initially a larger volume flow can be sucked off via the one CD-suction opening area and then over the other CD-suction opening area.

A proven embodiment of the monomer extraction device according to the invention is characterized in that a CD extraction opening region, preferably two CD extraction opening regions opposite the spinning field, extend over the entire width of the spinning field or essentially over the entire width of the spinning field. It is recommended that in each case over the entire width or essentially different volume flows can be sucked over the entire width of the two opposite CD-suction opening areas. As already indicated above, the extraction of different volume flows also means that no volume flow or substantially no volume flow of gas is sucked off via a CD suction opening region and that a volume flow of gas is sucked off only in the CD suction opening region opposite the spinning field becomes. Furthermore, different extraction of volume flows here also means that a volume flow of gas is supplied via a CD extraction opening region and gas is drawn off in the other CD extraction opening region opposite the spinning field.

A proven embodiment of the monomer extraction device according to the invention is characterized in that in a CD extraction opening area across its entire length transverse to the machine direction, a larger volume flow is deducted or withdrawn than in the opposite with respect to the spinning field CD-suction opening area. - It is also within the scope of the invention that are provided on each side of the spinning field transverse to the machine direction successively arranged CD-Absaugungsöffnungs-sections and that is sucked through at least one CD-Absaugungsöffnungs partial area on the first side of the spinning field, a higher volume flow than through an opposing CD suction port portion on the second side of the spinning field. On the other hand, a smaller volume flow can be sucked off by at least one further CD-suction opening partial area on the first side of the spinning field than by an opposite or directly opposite CD-suction opening partial area on the second side of the spinning field. In this case, the provided on one side of the spinning field CD extraction port portions may be arranged with different gas flow direction directly adjacent to each other transversely to the machine direction or at a distance from each other. Thus, a plurality of pairs of opposing CD exhaust port portions may be distributed across the width of the spinneret, so conveniently for each pair of CD exhaust port portions on opposite sides of the spinner, the proviso that through a CD Exhaust port portion a larger volume flow of gas is sucked than by the other immediately opposite CD exhaust port portion.

According to the invention, the ratio of the volume flow V ₁ extracted by a CD suction opening area to the volume flow V _{2 drawn} off by the other CD suction opening area opposite to the spinning field is 6: 1 to 1.1: 1, preferably 5.5: 1 to 1.3: 1, preferably 5.5: 1 to 1.5: 1 and more preferably 5: 1 to 1.75: 1. The aforementioned volume flow conditions can also be realized for opposite partial areas of the CD extraction opening areas (opposite CD suction opening partial areas). Preferably, a plurality of pairs of CD exhaust opening portions are then evenly distributed in the CD direction.

A recommended embodiment of the invention is characterized in that a CD suction opening region is formed as at least one - in a preferred embodiment as a CD suction gap extending in the CD direction. According to one embodiment variant, the CD suction gap is in a plurality of CD suction gap sections divided. According to a preferred embodiment, in the CD direction 4 to 40, preferably 6 to 35 and preferably 8 to 30 CD-Absaugungsspaltabschnitte are preferably arranged side by side at the same vertical height. The length of these CD-Absaugungsspaltabschnitte in the CD direction is suitably each 10 to 70 cm, preferably 10 to 60 cm and preferably 15 to 40 cm. The juxtaposed CD-Absaugungsspaltabschnitte complement each other in the CD direction extending CD Absaugungsspalt. In principle, two or more CD suction gaps or CD suction gap sections can also be arranged one above the other in the vertical direction on each side of the spinning field.

It is within the scope of the invention that the opening cross-sectional area of the at least one CD-suction gap arranged on one side of the spinning field is larger than the opening cross-sectional area of the at least one CD-suction gap arranged on the other side of the spinning field , Thus, for example, the opening cross-sectional area of the at least one or in the machine direction rear CD suction gap (outlet side of the spunbonded web) larger than the opening cross-sectional area of the one or at least one seen in the machine direction CD front suction gap (inlet side of the spunbonded web) or vice versa.

According to a recommended embodiment, the gap height h or the vertical gap height h of the two opposite CD extraction gaps is different, for example, the gap height h _{A of} the rear CD suction gap in the machine direction (outlet side of the spunbonded web) is greater than the gap height h _E of in Machine direction of the front CD extraction gap (inlet side of the spunbonded nonwoven web). - Appropriately, the Gap height h of a CD-suction gap more than twice as large, preferably more than three times as large as the gap height h of the other CD-suction gap. The CD suction gaps are recommended to have a gap height or a vertical gap height h of 2 to 50 mm, preferably 4 to 40 mm and preferably 4 to 35 mm. According to a preferred embodiment of the invention, the gap height h of the higher CD suction gap is 20 to 50 mm, advantageously 25 to 45 mm, and the gap height h of the lower CD suction gap is preferably 2 to 12 mm, in particular 2 to 10 mm. Basically, the two opposing CD-Absaugungsspalte but also have the same height and the differently extracted at the two CD-Absaugungsspalten volume flow is then by settings - especially cross-sectional settings, in particular at the at least one collecting chamber or at the collecting chambers and / or at the Suction line or on the suction lines - realized. As already explained above, it is also within the scope of the invention that the suction of the higher volume flow continuously changes from one side of the monomer suction device to the other side of the monomer suction device or continuously between the one CD suction gap and the other CD suction gap. In principle, it would also be possible to set the gap height of the CD extraction gaps alternately.

The different volume flows extracted in the context of the monomer extraction according to the invention by at least two CD extraction opening regions opposite to the spinning field can be determined by the geometrical parameters of the CD extraction opening regions or CD extraction opening regions and in particular the CD suction gap or CD suction gap segments be set. Alternatively or In addition, these different volume flows can also be adjusted by the configuration or design of each collection chamber / collecting chambers associated with each CD suction opening area and / or suction line / suction lines and / or collecting pipe / collecting pipes. As already explained above, a CD extraction opening area is expediently assigned at least one or a collection chamber to which / at least one suction line, expediently a plurality of suction lines is / are connected. By the number and / or the size or the cross section of the suction lines, the volume flow drawn off at the respective CD extraction opening area can be adjusted. It is recommended that two to twelve suction lines per m spinning field, preferably four to ten suction lines per m spinning field are connected to a, a CD-extraction opening area associated collection chamber, is sucked through the gas from the collection chamber. It is within the scope of the invention that the device according to the invention has at least two collecting chambers and preferably in each case one collecting tube connected to each collecting chamber.

A particularly preferred embodiment of the monomer suction device according to the invention is characterized in that the monomer suction device has at least two MD suction opening regions extending in the machine direction (MD) and opposite the spinning field. The MD suction opening regions are provided in the area of the spinnerette and preferably in the end walls which delimit the filament-forming space below the spinnerette and which extend in the MD direction. It is within the scope of the invention that the end walls and thus also the MD suction opening areas are shorter or significantly shorter than those in the CD direction extending side walls of the filament forming space and thus also as the CD suction port areas. The MD exhaust port areas are conveniently located transversely, preferably perpendicular to the CD exhaust port areas. Also, via the MD suction opening areas, as with the CD suction opening areas, gases are sucked off or sucked out of the filament forming space below the spinnerette. Expediently, an MD suction opening region is designed as at least one or MD extracting gap extending in the MD direction. According to one embodiment, such an MD suction gap is subdivided into a plurality of MD suction gap sections, in particular into two to five MD suction gap sections, preferably into two to three MD suction gap sections. The MD suction gap sections are preferably arranged one behind the other in the MD direction and are expediently at the same vertical height or at substantially the same vertical height. The length of the MD suction gap sections is preferably in each case 10 to 70 cm, preferably 10 to 60 cm, particularly preferably 15 to 40 cm and in particular 10 to 20 cm. The length is measured in the MD direction. The vertical gap height h of an MD suction gap or MD suction gap section is recommended to be 2 to 50 mm, preferably 25 to 45 mm and very preferably 2 to 12 mm. According to an embodiment variant, the suction through the MD suction opening areas can be regulated separately or independently of the suction through the CD suction opening areas. According to another embodiment of the invention, the MD suction port areas are connected to the collection ports of the CD exhaust port areas. Thus, in each case one MD-suction opening area can be connected to at least one collecting chamber or to at least one collecting tube of a CD-suction opening area be connected. Then expediently in each case a common suction through a CD-suction opening area and an associated MD-suction opening area.

It is within the scope of the invention that two opposite CD-suction opening areas - preferably two opposite CD-suction gaps - at the same vertical height or substantially the same vertical height as two opposite MD-suction opening areas - preferably like two opposite MD- Absaugungsspalte - lie. In principle, a continuous suction gap could circulate over the circumference of the spinning field. According to a preferred embodiment of the invention, however, both the opposing CD suction gaps and the opposing MD suction gaps are subdivided into CD-suction gap sections and MD suction gap sections arranged side by side, expediently at the same or essentially the same vertical height.

It is further within the scope of the invention that a CD suction opening area or a CD suction gap is longer or substantially longer than an MD suction opening area or MD suction gap. Preferably, a CD suction opening area or CD suction gap is at least twice as long, preferably at least 2.5 times as long, more preferably at least 3 times as long and in particular at least 4 times as long as an MD suction opening area or MD Absaugungsspalt. The abovementioned lengths are measured transversely or preferably perpendicular to the machine direction (CD direction) and in the machine direction (MD direction).

The total volume of gas extracted by the CD suction opening areas and preferably the MD suction opening areas is, according to a preferred embodiment of the invention, 35 to 1200 m ³ / h per m spinning field, preferably 40 to 1100 m ³ / h per m spinning field and preferably 50 to 1000 m ³ / h per m spinning field. In this case, according to the invention, a higher volume flow is extracted via a CD suction opening area than via the CD suction opening area opposite the spinning field.

It is possible that in the apparatus according to the invention on a suction side (in particular in the region of a CD-suction opening area) due to the throttled volume flow contamination or contamination of the surfaces - especially by condensation - occur. These contaminants can be reduced by suitable gas guidance. According to one embodiment of the invention, contaminated surfaces in the region of at least one suction opening region or CD extraction opening region are covered by contaminants or condensate-receiving, in particular absorbing, adsorbing and / or insulating covering materials or covering webs. The cover materials or cover sheets are fixed in a suitable manner to the vulnerable surfaces. To cover, for example, meltblown webs or the like can serve. Alternatively or additionally, according to a recommended embodiment variant, the surfaces subject to contamination are tempered, in particular heated, to avoid contamination or condensation.

The invention is based on the finding that the technical problem according to the invention can be solved particularly effectively if, on the one hand, the The above-explained features of Monomerabsaugung be realized and if on the other hand certain conditions are observed in the design of the spinnerette or with respect to the capillaries of the spinnerette. The capillary of the spinnerette means the channels through which the plastic melt is guided for the filaments spun with the spinnerette. According to a particularly preferred embodiment of the device according to the invention, the spinnerette has a capillary density of 1 to 6 capillaries / cm ² , preferably 2 to 5 capillaries / cm ² , preferably 2 to 4.5 capillaries / cm ² , especially 2 to 4 capillaries / cm ^2, and more preferably from 2.2 to 3.2 capillaries / cm ² . It is recommended that the capillary density of the spinnerette in the central region of the spinnerette is lower than in the outer regions of the spinnerette and that preferably the capillary density in the middle region of the spinnerette is 0 to 1 capillaries / cm ² . The inner diameter of the capillaries is recommended to be 0.2 to 0.9 mm, in particular 0.3 to 0.8 mm. These preferred features of the spinnerette have proven particularly useful in the context of the invention in connection with the different suction of the volume flows in the monomer extraction according to the invention.

The spinning field depth is expediently 120 to 400 mm, preferably 150 to 350 mm, very preferably 170 to 300 mm and particularly preferably 185 to 270 mm. Spinning field depth means in particular the extent of the spun filament bundle in the machine direction (MD). According to a particularly recommended embodiment of the invention, the spinning field depth is 195 to 260 mm. In the abovementioned spider field depths, the technical problem according to the invention can be solved without difficulty and defects or defects in the deposited spunbonded nonwoven web can be avoided or considerably reduced in comparison with the known measures. at the measures known from practice occurred on unwanted inhomogeneities or defects in the deposited spunbonded web, especially at larger spider field depths. This disadvantage can be effectively avoided with the device according to the invention.

A particularly recommended embodiment of the device according to the invention is characterized in that in the filament flow direction behind the Monomerabsaugungsvorrichtung a cooling device and an adjoining drawing unit is provided. It is recommended that the drawing unit has an intermediate channel converging in the filament flow direction and a drawing channel connected thereto. - According to a particularly preferred embodiment of the invention, the intermediate channel at least two in the flow direction of the filaments in a row or with each other arranged converging channel sections. It is recommended that the first or upper channel section in the flow direction of the filaments have a shorter length than the second or lower channel section in the flow direction of the filaments. Preferably, the opening angle of the first or upper converging channel section of the intermediate channel is greater than the opening angle of the second or lower converging channel section of the intermediate channel. It is within the scope of the invention that the intermediate channel or the lower converging channel section of the intermediate channel as it transits into the Verstreckkanal or Unterziehkanal the stretching unit. The intermediate channel or the lower channel portion of the intermediate channel and the Verstreckkanal or Unterziehkanal can basically have the same convergence.

Conveniently, at least one diffuser is provided in the filament flow direction behind the drawing unit and an adjoining storage device for depositing the filaments to the spunbonded nonwoven. In the context of the invention, it is particularly preferred that at least two diffusers, in particular two diffusers, be provided in the filament flow direction behind the drawing unit, and it has proven useful to provide at least one ambient air inlet gap or one ambient air inlet gap for the entry of ambient air between the two diffusers. - A particularly recommended embodiment of the device according to the invention is characterized in that the unit of cooling device and drawing unit is designed as a closed system in which except the supply of cooling air in the cooling device no further air supply. The invention is based on the finding that the monomer extraction device according to the invention works optimally, especially in combination with such a closed system.

To solve the technical problem, the invention further teaches a method for producing spunbonded non-wovens, in particular from continuous filaments of thermoplastic material, wherein the filaments are spun by means of a spinnerette, wherein emerging in the filament forming space in the spinnerette, in particular below the spinnerette during the spinning process gases be sucked off (Monomerabsaugung),
wherein at least two in the machine direction (MD) successively arranged CD-suction port areas each having at least a volume flow of the resulting gases is sucked, wherein the suctioned through a CD exhaust port area volume flow is greater than that through the other CD-suction opening area extracted volume flow, the filaments are then cooled and stretched and finally stored on a storage device to the spunbonded,
wherein the ratio of the volume flow V drawn off by one CD suction opening area to the volume flow V drawn off by the other CD suction opening area lying opposite to the spinning field is 6: 1 to 1.1: 1, preferably 5.5: 1 to 1, 3: 1, preferably 5.5: 1 to 1.5: 1 and more preferably 5: 1 to 1.75: 1.

A particularly proven embodiment of the method according to the invention is characterized in that the filaments with a throughput of 100 to 350 kg / h / m, preferably with a throughput of 150 to 320 kg / h / m, preferably with a throughput of 180 to 300 kg / h / m and very preferably produced at a throughput of 200 to 300 kg / h / m. Insofar as the invention is based on the recognition that technical problem of the invention - especially the avoidance of inhomogeneities and defects in the spunbonded nonwoven web - especially at higher flow rates can be solved easily. It is within the scope of the invention that the filaments are produced at a yarn speed of 2,000 to 4,200 m / min, preferably 2,200 to 4,000 m / min and in particular 2,300 to 3,900 m / min.

The invention is based on the finding that spun nonwovens can be produced with the device according to the invention and with the method according to the invention, which are distinguished by excellent homogeneity and virtually do not have defects or defects. With the device according to the invention, the above-described disadvantageous drops and hard pieces are largely avoided or reduced to a minimum. It is of particular advantage that a virtually flawless nonwoven storage is possible even with deep or wide spinning fields and at high throughputs and at high yarn speeds. In addition to the monomer extraction according to the invention further complicated measures for realizing the advantages according to the invention are generally not required. Above all, expensive additional device components for effectively solving the technical problem are not necessary. Of particular importance in the context of the invention is the combination of the monomer extraction characteristics on the one hand and the design of the spinnerette on the other hand. Reference is made to the capillary features of the spinnerette set forth above. As a result, with the device according to the invention and with the method according to the invention, a surprisingly homogeneous and faultless spun-bonded fabric deposit can be achieved at relatively deep spinning fields and relatively high throughputs. This is surprising insofar as the defect rate usually increases with previously known devices and methods at higher throughputs. In view of the considerable advantages achieved, the device according to the invention is characterized by simplicity and relatively low costs.

Fig. 1

einen Vertikalschnitt durch eine erfindungsgemäße Vorrichtung,

Fig. 2

einen vergrößerten Ausschnitt aus der Fig. 1 und zwar

1. a) mit einer Monomerabsaugung gemäß dem Stand der Technik und
2. b) mit einer erfindungsgemäßen Monomerabsaugung und

Fig. 3

eine perspektivische Darstellung einer erfindungsgemäßen Monomerabsaugungsvorrichtung.

The invention will be explained in more detail with reference to a drawing showing only one exemplary embodiment. In a schematic representation:

Fig. 1

a vertical section through a device according to the invention,

Fig. 2

an enlarged section of the Fig. 1 in fact

1. a) with a monomer extraction according to the prior art and
2. b) with a monomer extraction according to the invention and

Fig. 3

a perspective view of a monomer extraction device according to the invention.

The figures show a device according to the invention for the production of spunbonded nonwovens 22 from endless filaments 23, wherein the filaments 23 consist in particular of thermoplastic material or consist substantially. The filaments 23 are spun with a spinnerette 1 and are guided in a filament-forming space 29 below this spinnerette 1 by a monomer suction device 2 for the extraction of gases produced in the spinning process. In the direction of flow of the filaments behind or below the Monomerabsaugungsvorrichtung 2, a cooling device 3 is provided for cooling the filaments. Preferably, and in the embodiment, this cooling device 3, an air supply cabin, which is divided in the embodiment in two cabin sections 13, 14. From these two cabin sections 13, 14, preferably and in the exemplary embodiment, in each case process air or cooling air of different temperature can be supplied in the direction of the filament bundle. To the cooling device 3 includes a drawing unit 15 in the flow direction of the filaments. This stretching unit 15 has, preferably and in the exemplary embodiment, an intermediate channel 24 converging in the direction of flow of the filaments and an adjoining drawing channel 25. Empfohlenermaßen and in the embodiment, the aggregate of the cooling device 3 and the drawing unit 15 is formed as a closed system. In this closed system, apart from the supply of the cooling air or process air in the cooling device 3, no further air supply takes place. After preferred Embodiment of the invention includes in the flow direction of the filaments to the drawing unit 15 at least one diffuser 17, 18 at. Appropriately, and in the embodiment, two mutually or successively arranged diffusers 17, 18 are provided. It is recommended that between the two diffusers 17, 18, an ambient air inlet gap 28 is provided for the entry of ambient air. Preferably and in the exemplary embodiment, the filaments 23 are deposited on a depositing device 16 to the spunbonded nonwoven web following the diffusers 17, 18. Preferably, and in the embodiment, the storage device 16 is formed as an endlessly circulating Ablagesiebband.

According to the invention, in the region of the spinnerette 1, the monomer extraction device 2 is arranged for the extraction of gases produced during the spinning process. Preferably and in the exemplary embodiment, the monomer suction device 2 is arranged in the filament-forming space 29 below the spinnerette 1. Empfohlenermaßen and in the embodiment, this Monomerabsaugungsvorrichtung 2 has two in the machine direction (MD) arranged one behind the other, each extending transversely to the machine direction and with respect to the spinning field 4 opposite CD-suction opening areas 5, 6. The CD-suction opening areas 5, 6 are preferably and, in the exemplary embodiment, provided in opposite side walls 26 extending in the CD direction and delimiting the filament-forming space 29. These CD-suction opening areas 5, 6, which are opposite to the spinning field 4, are preferably and in the exemplary embodiment in each case designed as a CD-suction gap 7, 8 extending transversely or perpendicular to the machine direction. Preferably, and in the exemplary embodiment, the two CD-suction gaps 7, 8 are each in a plurality of CD-Absaugungsspaltabschnitten 7 ', 8' divided. These CD-suction gap sections 7 ', 8' are preferred and, in the exemplary embodiment, arranged next to each other and at the same vertical height. It is within the scope of the invention that the two opposing CD-Absaugungspalte 7, 8 are set with the proviso that one of the two CD-Absaugungsspalte 7, 8, a higher volume of gases is sucked as over the other opposite CD-Absaugungsspalt. 7 8. In the exemplary embodiment, a higher volume flow V _{A can be} sucked off by the CD suctioning gap 8 seen in the machine direction (outlet side of the spunbonded web) than through the CD suction gap 7 in the machine direction (inlet side of the spunbonded web). In this case, the ratio of the volume flows V _A / V _E in the exemplary embodiment may be 3: 1. In the exemplary embodiment, the vertical gap height h _{A of} the seen in the machine direction rear CD suction gap 8 (outlet side) is greater than the vertical gap height h _{E of} the machine seen in front CD suction gap 7 (inlet side). However, a higher volume flow V _{E can also be} sucked off by the CD suctioning gap 7 seen in the machine direction (inlet side of the spunbonded web) than through the rear CD suction gap 8 seen in the machine direction (outlet side of the spunbonded web). The ratio of the volume flows and the vertical gap heights can then be provided in reverse, as it were, according to the above information.

The depth t of the spinning field 4 may be 200 mm in the exemplary embodiment and in the embodiment may be worked with a throughput of 230 kg / h / m and with a yarn speed of 3,300 m / min.

According to a preferred embodiment and in the embodiment, the monomer suction device 2 further comprises two in the machine direction (MD) extending and with respect to the spinning field 4 opposite MD-suction opening areas 9, 10. The MD suction opening areas 9, 10 are preferably and in the exemplary embodiment in opposite, extending in the MD direction and the filament forming space bounding end walls 27 are provided. The end walls 27 connect expediently to the side walls 26 extending in the CD direction. The side walls 26 (in the CD direction) are recommended here and in the embodiment longer or significantly longer than the side walls 27 (in the MD direction). The MD suction port regions 9, 10 are preferred and, in the exemplary embodiment, are formed as two MD MD-suction gaps 11, 12 extending in the MD direction. The MD suction gaps 11, 12 are furthermore expediently and in the exemplary embodiment arranged at the same vertical height and also arranged at the same vertical height as the CD suction gaps 7, 8. The MD suction gaps 11, 12 are also preferably and in the exemplary embodiment subdivided in each case into MD suction gap sections 11 ', 12' and indeed recommended, and in the exemplary embodiment in each case into two MD suction gap sections 11 ', 12'.

Conveniently and in the exemplary embodiment, each CD-suction gap 7, 8 is assigned a collecting chamber 19, 20 for the gases sucked off via the CD-suction gaps 7, 8. In this case, a plurality of suction lines 21 is connected to each collecting chamber 19, 20 for the extraction of gases in the context of Monomerabsaugung. Via the suction lines 21 and in the exemplary embodiment, each collecting chamber 19, 20 is connected in each case to a collecting tube 32, 33. Conveniently, at least one not shown suction unit - for example in the form of a pump - connected to the manifold 32, 33 for sucking the gases. henceforth can the suction 21 shut-off elements - for example in the form of shut-off valves - and also with these shut-off of the opposite CD-Absaugungsspalte 7, 8 each extracted volume flow can be adjusted. - Preferably, the manifolds 32, 33 except the CD-suction columns 7, 8 and the two opposite MD Absaugungsspalten 11, 12 assigned. The gases extracted via these MD suction gaps 11, 12 are thus collected in the collecting pipes 32, 33. - In the Fig. 3 Incidentally, it can be seen that guide plates 30, 31 are provided for the extracted gases in the collecting chambers 19, 20.

A comparative analysis of the Fig. 2a and 2 B shows the gas flows in the monomer extraction according to the prior art ( Fig. 2a ) and the gas flows in the monomer extraction according to the invention ( Fig. 2b ). At the in Fig. 2a the monomer extraction device 2 shown in the prior art is sucked in each case over two with respect to the spinning field 4 CD exhaust port areas 5, 6, the same volume flow of gases. It can be seen here that the filament bundle spun by means of spinnerette 1 is not acted upon by the gas flows in its center. Insofar as the invention is based on the recognition that it can come to the filaments in this embodiment for droplet formation and / or hard-piece formation, which - as described above - defects or defects in the deposited spunbonded web result. - In contrast, in the monomer extraction according to the invention - as in Fig. 2b recognizable - sucked on the one side of the spinning field 4, a higher volume flow. In the exemplary embodiment, a higher volume flow V _{A is} aspirated than through the in FIG. 9 in the machine direction (MD) rear CD suction gap 8 (outlet side of the spunbonded web) Machine direction seen front CD-suction 7 (inlet side of the spunbonded web). As in Fig. 2b Furthermore, this leads recognizably to the fact that the gas flows also act on the filaments arranged in the middle of the spun filament bundle. The invention is based on the finding that this effectively prevents the formation of droplets and hard pieces on the filaments and therefore also defects or defects in the deposited spunbonded nonwoven web can be avoided. In the Fig. 2a and 2 B Incidentally, the introduction of cooling air in the cooling device 3 is also shown. The inflowing cooling air is symbolized here by the downward arrows.

Claims (20)

1. An apparatus for manufacturing spunbond nonwovens (22) from continuous filaments (23), in particular continuous filaments (23) of a thermoplastic material, wherein
   a spinneret (1) is provided for spinning the filaments and a cooling device (3) is provided for cooling the filaments, wherein at least one monomer suction device (2) for suctioning gases produced during the spinning process is arranged in the area of the spinneret (1), in particular between spinnaret (1) and cooling device (3) ;
   wherein the monomer suction device (2) has at least two CD suction opening regions (5, 6) which are arranged one behind the other in the machine direction (MD), each of which extends transversely to the machine direction and which lie opposite each other in relation to the spinning field (4) and wherein the two CD suction opening regions (5, 6) and/or wherein at least two opposite CD suction opening subregions (5', 6') of the CD suction opening regions (5, 6) are adapted with the proviso that a higher volume flow of gas or gases can be suctioned via one of the two CD suction opening regions (5, 6) and/or CD suction opening subregions (5', 6') than over the other opposite CD suction opening region (5, 6) and/or CD suction opening subregions (5', 6') so that the ratio of the volume flow V suctioned by one CD suction opening region (5, 6) and/or CD suction opening subregions (5', 6') to the volume flow V suction by the other opposite CD suction opening region (5, 6) and/or CD suction opening subregion (5', 6') in relation to the spinning field (4) is 6:1 to 1.1:1, preferably 5.5:1 to 1.3:1, preferably 5.5:1 to 1.5:1 and particularly preferably 5:1 to 1.75:1.
2. The apparatus according to claim 1, wherein the opening area A of the CD suction opening region (5, 6) is or is adjustable over 11,000 mm²/m spinning field (4) - measured transversely to the machine direction or CD direction - is preferably or is adjustable over 12,000 mm²/mm spinning field (4), expediently over 20,000 mm²/m spinning field (4), preferably over 30,000 mm²/m spinning field (4), very preferably over 40,000 mm²/m spinning field (4) and particularly preferably over 50,000 mm²/m spinning field (4) and wherein preferably the respective opening areas of the CD suction opening regions (5, 6) are designed or are adjustable with the proviso that a higher volume flow can be suctioned through one of the two opposite CD suction opening regions (5, 6) than through the other CD suction opening region (5, 6).
3. The apparatus according to one of claims 1 or 2, wherein the opening area of one CD suction opening region (5, 6) is greater or can be adjusted to be greater than the opening area of a second opposite CD suction opening region (5, 6) in relation to the spinning field.
4. The apparatus according to one of claims 1 to 3, wherein one CD suction opening region (5, 6), preferably two CD suction opening regions (5, 6) in relation to the spinning field (4) extend over the entire width of the spinning field (4) or substantially over the entire width of the spinning field (4).
5. The apparatus according to one of claims 1 to 4, wherein different volume flows can be suctioned in each case over the entire width or substantially over the entire width of the two opposite CD suction opening regions (5, 6) and wherein preferably in one CD suction opening region (5, 6) a larger volume flow can be extracted over its entire width transverse to the machine direction than in the opposite CD suction opening region (5, 6).
6. The apparatus according to one of claims 1 to 5, wherein one CD suction opening region (5, 6) is configured as at least one CD suction gap (7, 8) extending in the CD direction and wherein preferably the CD suction gap (7, 8) is divided into a plurality of CD suction gap portions (7', 8').
7. The apparatus according to claim 6, wherein the gap height h of one CD suction gap (7, 8) is greater than the gap height h of the opposite CD suction gap (7, 8) in relation to the spinning field and wherein preferably the gap height h of the one CD suction gap (7, 8) is more than twice as great, preferably more than three times as great as the gap height h of the other CD suction gap (7, 8).
8. The apparatus according to one of claims 1 to 7, wherein each CD suction opening region (5, 6) is assigned as least one collecting chamber (19, 20) for the suctioned gases and wherein the different suctioned volume flows of the gases are adjustable by means of at least one throttle element which is preferably provided in or on a collecting chamber (19, 20) or in or on a suction line (21) connected to the collecting chamber (19, 20).
9. The apparatus according to one of claims 1 to 8, wherein a higher volume flow can be suctioned in turn by the one CD suction opening region (5) and by the other CD suction opening region (6).
10. The apparatus according to one of claims 1 to 9, wherein the monomer suction device (2) comprises at least two MD suction opening regions (9, 10) which extend in the machine direction (MD) and which lie opposite each other in relation to the spinning field (4), wherein preferably one MD suction opening region (9, 10) is configured as at least one MD suction gap (11, 12) extending in the MD direction and wherein according to one embodiment an MD suction gap (11, 12) is divided into a plurality of MD suction gap portions (11', 12').
11. The apparatus according to one of claims 1 to 11, wherein surfaces liable to contamination in the area of the suction opening regions, in particular in the area of at least one CD suction opening region (5, 6) are covered by contamination-holding, in particular absorbing, adsorbing and/or isolating covering materials or covering webs.
12. The apparatus according to one of claims 1 to 11, wherein surfaces liable to contamination in the area of the suction opening regions, in particular in the area of at least one CD suction opening region (5, 6) can be temperature-controlled, in particular can be heated to avoid contamination or to avoid condensate formation.
13. The apparatus according to one of claims 1 to 12, wherein the spinneret (1) has a capillary density of 1 to 6 capillaries/cm², preferably of 2 to 5 capillaries/cm², in particular of 2 to 4.5 capillaries/cm² and preferably of 2 to 4 capillaries/cm².
14. The apparatus according to one of claims 1 to 12, wherein the capillary density of the spinneret (1) in the central region of the spinneret (1) is lower than that in the outer regions of the spinneret (1) and wherein preferably the capillary density in the central region of the spinneret (1) is 0 to 1 capillary/cm².
15. The apparatus according to one of claims 1 to 14, wherein the depth t of the spinning field is 120 to 350 mm, preferably 150 to 300 mm and particularly preferably 185 to 270 mm and wherein it is recommended that the depth t of the spinning field (4) is more than 140 mm, preferably more than 160 mm, very preferably more than 200 mm and particularly preferably more than 210 mm.
16. The apparatus according to one of claims 1 to 15, wherein the cooling device (3) has at least two compartment sections (13, 14) arranged above one another or behind one another from which air or cooling air at different temperatures can enter.
17. The apparatus according to one of claims 1 to 16, wherein a cooling device (3) and an adjoining stretching unit (15) are provided in the filament flow direction downstream of the monomer suction device (2) and wherein a depositing device (16) for depositing the filaments to form the spunbond nonwoven is arranged in the filament flow direction downstream of the stretching unit (15) and wherein the unit comprising cooling device (3) and stretching unit (15) is configured as a closed system in which closed system no further supply of air takes place apart from the supply of cooling air in the cooling device (3).
18. Method for manufacturing spunbond nonwovens (22) from continuous filaments (23), in particular from continuous filaments (23) of thermoplastic material, wherein the filaments are spun by means of a spinneret (1), wherein gases formed during the spinning process are suctioned in the filament forming space below the spinneret (1) (monomer suction), wherein in each case at least one volume flow of the gases produced is suctioned by at least two CD suction opening regions (5, 6) arranged one after the other in the machine direction (MD), wherein the volume flow suctioned by the one CD suction opening region (5, 6) is greater than the volume flow suctioned by the other CD suction opening region (5, 6), wherein the ratio of the volume flow V suctioned by one CD suction opening region (5, 6) to the other volume flow V suctioned by the other CD suction opening region (5, 6) which lies opposite in relation to the spinning field (4) is 6:1 to 1.1:1, preferably 5.5:1 to 1.3:1, preferably 5.5:1 to 1.5:1 and particularly preferably 5:1 to 1.75:1.
19. The method according to claim 18, wherein the filaments are produced with a throughput of 100 to 350 kg/h/m, preferably with a throughput of 150 to 320 kg/h/m, preferably with a throughput of 180 to 300 kg/h/m and very preferably with a throughput of 200 to 300 kg/h/m.
20. The method according to one of claims 18 or 19, wherein the filaments are produced with a thread speed of 2000 to 4200 m/min, preferably with a thread speed of 2200 to 4000 m/min and in particular with a thread speed of 2300 to 3900 m/min.

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