EP2128320B1 - Method and device for the manufacture of nonwoven material from filaments - Google Patents

Description

The invention relates to a process for producing spunbonded nonwovens of filaments, in particular of thermoplastic material. Furthermore, the invention also relates to a device for producing such spunbonded nonwovens. Filaments means in the context of the invention, in particular endless filaments. Endless filaments differ because of their quasi-endless length of staple fibers, which have much smaller lengths of, for example, 10 to 60 mm.

Methods and devices of the type mentioned are known from practice in various embodiments. In these methods, the filaments are spun using a spinning device and placed on a tray, in particular on a storage conveyor belt or Ablagesiebband to nonwoven web. It is known to pre-consolidate this nonwoven web by hydroentanglement. The water jet treatment is usually carried out only from one side of the nonwoven web. Thereafter, the preconsolidated filament deposit or nonwoven web is detached from the deposit screen belt and fed to a separate water jet device for hydroentanglement or for hydraulic final consolidation. At high basis weights of the nonwoven web about 80 g / m ² , in particular more than 100 g / m ² and especially above 150 g / m ² has been shown that it is possible only under very high water pressures, the dense Filamentablage or Nonwoven web to pre-consolidate down to the lower filaments. This is associated with a relatively high energy consumption. Incidentally, this hydrodynamic preconsolidation causes a relatively high compression of the nonwoven web. In hydraulic final consolidation, the water jets then hit a relatively dense barrier, which they must penetrate in such a way that the filaments loop over the web thickness become. In particular, in nonwoven webs with higher basis weights to an increased water pressure and thus a relatively high energy input is required. In this hydraulic final consolidation, it is customary that the energy input of the successively staggered water jet nozzles and the first increases to the other nozzles. The nozzles with the highest energy input are arranged as with respect to the conveying direction of the nonwoven web at the end or in the middle of the water jet device. For nonwoven webs with a very high basis weight, the energy input is so high that the process is no longer practicable.

An alternative solution is to clamp the loose Filamentablage or nonwoven web between two idler sieve bands and then perform through these sieve bands through the water jet treatment. In this procedure, however, the screen belts disadvantageously reflect part of the water energy, so that the energy balance leaves something to be desired here as well.

In WO 01 / 25529A is a heel lining for the shoe industry and a method for producing such a heel chuck described. The heel lining is made of a nonwoven fabric with basis weights of 180 to 350 g / m ² . The fleece deposit or the nonwoven fabric is first pre-consolidated. This pre-consolidation can be done by calendering or by needling. A final consolidation is then performed as hydroentanglement.

In DE 100 61 367 A1 is described a cover for a side airbag. This shell consists of a consolidated polyester spunbonded nonwoven. The polyester spunbonded nonwoven fabric can be preconsolidated thermally or by mechanical needling. The final consolidation of the web is also done here by water jet needling.

EP-A-1 561 848 relates to a process for producing a spunbonded filament. First, a pre-consolidation of the nonwoven web is performed. Then the nonwoven web is moistened and then finally solidified by hydrodynamic consolidation.

The document EP-A-1 447 466 also relates to a process for producing a spunbonded filament. The nonwoven web is first preconsolidated in a calender and then treated with a wetting agent. This is followed by hydrodynamic final consolidation of the spunbonded nonwoven.

The invention is based on the technical problem to provide a method of the type mentioned, with a nonwoven web, especially with higher basis weights over about 80 g / m ² and above all about 100 g / m ² in a simple and inexpensive manner and can be solidified with the lowest possible use of energy or total energy input. The inventive method is particularly suitable for nonwoven webs with basis weights from 150 g / m ² . The invention is further based on the technical problem of specifying a corresponding device for the production of spunbond webs.

To solve this technical problem, the invention teaches a method for the production of spunbonded nonwovens from filaments, in particular from thermoplastic material,
wherein the filaments are spun from at least one spinning device, then cooled and stretched and then deposited on a tray to the nonwoven web,
wherein the nonwoven web is preconsolidated by mechanical needling, wherein after filing the filaments to the nonwoven web and before the mechanical Needle punching the nonwoven web a liquid medium is introduced into the nonwoven web,
wherein the nonwoven web is subsequently finally consolidated by hydrodynamic consolidation
and wherein the final-bonded nonwoven web has a basis weight of more than 80 g / m ² , preferably more than 100 g / m ² and more preferably more than 150 g / m ² .

Mechanical needling means the needling of the nonwoven web with a needle device or needle machine, which usually has a plurality of needles, which penetrate into the nonwoven web during needling. Hydrodynamic consolidation or hydraulic consolidation means solidification with high pressure water jets acting on the nonwoven web.

The titre of the filaments in the nonwoven web is suitably 0.6 to 10 den, preferably 1 to 6 den, and particularly preferably 1 to 3 den. For filament mixtures, the titre of the filaments may also be 0.05 to 20 den. The inventive method proves particularly at lower titers between 0.05 den and 10 den, preferably between 0.05 and 6 as particularly advantageous since the fiber web or nonwoven web is then relatively dense and nonetheless a solidification with relatively low energy input is possible , The inventively produced nonwoven webs of finer fibers are characterized by an advantageously high strength.

It is within the scope of the invention that the filaments are cooled after exiting the spinning device in a cooling chamber and stretched in a drafting device or aerodynamically stretched. It lies Furthermore, in the context of the invention that the stretched filaments are guided after the drawing device by a laying device having at least one diffuser. Following the installation device or following the diffuser, the filaments are then deposited to the nonwoven web. Storage means, in particular, a storage belt or storage belt.

According to the invention, after the filaments have been deposited in the nonwoven web and before the preconsolidation by mechanical needling, a liquid medium is applied to the nonwoven web or introduced into the nonwoven web. It is within the scope of the invention that the liquid medium acts as a lubricant for mechanical needling. Such a lubricant reduces the incorporation of the (dry) filaments in the nonwoven web and facilitates the mechanical needling or reduces the required forces and thus the energy required for mechanical needling. Empfohlenermaßen is at least one liquid medium from the group "water, aqueous solution, aqueous mixture, oil, oily suspension" introduced into the nonwoven web. According to a preferred embodiment, water and / or an aqueous solution and / or an aqueous mixture is introduced into the nonwoven web.

A highly preferred embodiment of the invention is characterized in that a hydrophilic liquid medium is introduced into the nonwoven web. Hydrophilic liquid medium here means a liquid medium which gives the nonwoven web a hydrophilic character compared to the dry nonwoven web which has just been laid down. Dry nonwoven web here and below means the filament deposit or the nonwoven web before introducing the liquid medium or the hydrophilic liquid medium. The invention is based on the finding that with a hydrophilic liquid medium, the hydrodynamic final solidification connected downstream of the preconsolidation is also facilitated. According to one embodiment of the invention can then on the Pre-moistening between the preconsolidation and the hydrodynamic final consolidation, which is described below, is dispensed with.

Advantageously, the liquid medium or hydrophilic liquid medium is introduced into the nonwoven web by means of at least one spray bar and / or by means of at least one overflow weir. An embodiment of particular importance in the context of the invention is characterized in that the material introduced into the nonwoven web liquid medium is sucked in via at least one suction device in the nonwoven web. For this purpose, preferably at least one suction field or at least one suction device is arranged under a nonwoven web receiving Ablagesiebband. A negative pressure is expediently applied to the suction field, or a negative pressure is expediently applied by the suction device, which is preferably in the range between 50 and 400 mbar. According to a recommended embodiment, the suction or suction of the liquid medium via at least one suction device with at least one transverse to the conveying direction of the nonwoven web suction slot takes place. The introduction of the liquid medium, in particular of the hydrophilic liquid medium in the nonwoven web and the suitably carried out sucking or sucking the liquid medium has particularly for nonwoven webs with a basis weight over 130 g / m ² , in particular for nonwoven webs with a basis weight over 150 g / m ² proven.

According to a recommended embodiment of the invention, the liquid medium or hydrophilic liquid medium in an amount of 0.2 to 50%, preferably from 0.5 to 30%, very preferably from 0.5 to 20% and particularly preferably from 0.5 to 15% based on the weight of the dry nonwoven web or on the weight of a dry surface portion of the nonwoven web introduced into the nonwoven web. Appropriately, the introduction of the liquid medium with the proviso that the aforementioned amount of liquid medium remains in the pre-consolidation fed nonwoven web. It is, moreover, within the scope of the invention that the introduction of the liquid medium into the nonwoven web is not a solidification measure or not a hydrodynamic solidification.

According to a particularly preferred embodiment of the invention, the preconsolidation of the nonwoven web by the mechanical needling with a puncture density below 75 punctures / cm ² (E / cm ² ), preferably below 60 punctures / cm ² and preferably below 50 punctures / cm ² . The puncture density in the mechanical needling is in particular 5 to 75 punctures / cm ² , suitably 10 to 50 punctures / cm ² , recommended 10 to 40 punctures / cm ² and very preferably 12 to 30 punctures / cm ² . This preconsolidation serves to stabilize the fiber deposit or the nonwoven web for further treatment. Appropriately, the pre-consolidation is carried out by mechanical needling on the tray or on the storage belt / Ablagesiebband on which the filaments are deposited to the nonwoven web. It is within the scope of the invention that the preconsolidated nonwoven web is removed from the tray and at least one further device or conveyor for the purpose of further treatment is supplied.

According to one embodiment variant of the invention, the mechanically pre-bonded nonwoven web is transversely stretched before hydrodynamic final consolidation in a cross-stretching device, preferably in a range of 5 to 50%. This should increase the transverse strength and dimensional stability in the transverse direction. In principle, known measures such as sheet rolls, clamping frame systems, etc. can be used. When using a tenter, it may be convenient to choose the exit speed from this cross-stretching device less than the entry speed to achieve a more effective reorientation of the filaments while minimizing the transverse stretching forces. Such a transverse stretching would expediently in a range below the melting point of the nonwoven web raw material.

According to a preferred embodiment, which is of particular importance in the context of the invention, the nonwoven web is pre-moistened after the mechanical needling and before the hydrodynamic consolidation or final solidification. Subsequently, the hydrodynamic solidification by water jet treatment then takes place in at least one water jet device. According to a recommended embodiment, the pre-moistening is carried out by a first water jet unit, in particular by a first water jet beam, which is connected upstream of the actual water jet device for final consolidation and is operated at low water pressure. Low water pressure means in particular a water pressure of 5 to 120 bar and preferably from 20 to 100 bar. The higher water pressures relate to heavier nonwoven webs with higher basis weights of, for example, 200 g / m ² . Lighter nonwoven webs are pre-moistened at lower water pressures. It is within the scope of the invention that pre-moistening is carried out with the proviso that no appreciable densification of the filament deposit or nonwoven web takes place. According to another embodiment variant, the pre-wetting can also take place by means of a spraying device, with which water or an aqueous solution or aqueous mixture is sprayed onto the nonwoven web. Appropriately, there is a suction or suction of the liquid. The pre-wetting of the nonwoven web with water or with an aqueous system causes a better momentum transfer in the subsequent hydrodynamic consolidation / final consolidation. An alternative is that hydrophilic substances or additives are introduced into the nonwoven web. Also, this can improve the momentum transfer. - According to an embodiment of the invention can also be dispensed with the pre-moistening described above.

A particularly recommended embodiment of the invention is characterized in that the water jet treatment takes place at the hydrodynamic final consolidation both from the top and from the bottom of the nonwoven web forth. The upper side of the nonwoven web means the side of the nonwoven web facing the filament stream to be deposited. It is within the scope of the invention that the water jet treatment takes place in the hydrodynamic final consolidation with high-pressure water jets. High pressure water jets means in particular water jets, which have a water pressure of over 120 bar, suitably from 130 to 450 bar, preferably from 150 to 400 bar.

A very preferred embodiment, which is of very particular importance in the context of the invention, is characterized in that the water jet treatment is performed with at least one high-pressure water jet beam over the top of the nonwoven web and with at least one high-pressure water jet bar under the underside of the nonwoven web. Then, the top of the nonwoven web is thus acted upon by the high pressure water jets of one high pressure water jet bar and the bottom of the nonwoven web by the high pressure water jets of the other high pressure water jet bar. It is within the scope of the invention that a high-pressure water jet beam is arranged transversely to the conveying direction or transport direction of the nonwoven web. A high pressure water jet beam has a plurality of nozzles distributed along the length of the beam from which the high pressure water jets exit. According to a preferred embodiment of the invention, only two high-pressure water jet beams are provided, one of which is arranged above the upper side of the nonwoven web and of which the other is arranged below the underside of the nonwoven web. Conveniently, a maximum of four high pressure water jet beams for the hydrodynamic or Hydraulic final consolidation available. According to one embodiment, if more than four high-pressure water jet beams are used, the first four high-pressure water jet beams with respect to the conveying direction of the nonwoven web make up at least 80% of the total hydraulic work of the hydraulic final consolidation. The comparisons of the hydraulic work or the hydraulic hardening work relate here and below in particular to a respective nozzle bore of the beams to be compared or high-pressure water jet beams. In particular, the hydraulic work per nozzle bore of the beams to be compared is compared.

When working with at least two high pressure water jet beams, according to one embodiment, these two high pressure water jet beams differ in water pressure of the exiting high pressure water jets and / or nozzle hole density in hpi (nozzle holes per inch width) and / or nozzle hole diameter. Expediently, the high-pressure water jets of the first high-pressure water jet beam with respect to the conveying direction of the nonwoven web penetrate the entire nonwoven web thickness or essentially the entire nonwoven web thickness. Preferably, the second high-pressure water-jet beam second with respect to the conveying direction of the nonwoven web then acts from the opposite side of the nonwoven web. High-pressure water jets of this second high pressure water jet bar expediently penetrate at least 25%, preferably at least 30%, of the nonwoven web thickness. To the extent that the high pressure water jets of the second high pressure water jet beam penetrate the nonwoven web thickness, the energy or water energy of the first high pressure water jet beam can be reduced. According to a recommended embodiment of the invention, at least one high-pressure water jet beam of the first pair of high-pressure water jet beams with respect to the conveying direction of the nonwoven web is subjected to hydraulic solidification / final solidification through the entire nonwoven web thickness or essentially through the entire nonwoven web thickness. Possibly. Further downstream high-pressure water jet beams then expediently only act on near-surface filaments and serve for smoothening the nonwoven web surface or the nonwoven web surfaces.

It is within the scope of the invention that in the hydraulic solidification with a plurality of high-pressure water jet bar is working and the high pressure water jet bar with the highest hydraulic hardening work has a proportion of at least 33%, preferably a proportion of at least 40% and preferably a proportion of at least 50th % of total hydraulic consolidation work of hydroentanglement. It is recommended that the high pressure water jet bar with the highest hydraulic work hardening in the conveying direction of the nonwoven web is first or second or third high pressure water jet bar, preferably the first or second high pressure water jet bar. Preferably, the total hydraulic work hardening work of the hydraulic consolidation is less than 1 kWh / kg, preferably less than 0.8 kWh / kg.

According to a particularly recommended embodiment of the invention, hydraulic solidification is carried out with a water jet device, in particular with at least one high-pressure water jet beam, which has a hole density of less than 40 hpi, preferably less than 35 hpi and preferably less than 30 hpi. Hpi means "holes per inch width" or "nozzle holes per inch width". Conveniently, the first high-pressure water jet bar after the pre-moistening has the aforementioned hole density. Preferably, the high pressure water jet bar having the highest hydraulic work hardening has the aforementioned hole density. When the first high-pressure water jet bar with respect to the conveying direction of the nonwoven web, the aforementioned Having hole density, the downstream has another high-pressure water jet beam or have the downstream other high-pressure water jet beam expediently a higher hole density than the first high pressure water jet beam. The first high pressure water jet bar in the conveying direction of the nonwoven web preferably has a hole density of 20 to 30 hpi and the downstream second high pressure water jet bar has a hole density of 25 to 35 hpi, wherein the hole density of the second high pressure water jet bar is higher than the hole density of the first high pressure water jet bar. If a downstream third high-pressure water jet bar is provided, it preferably has a hole density of 30 to 45 hpi and preferably a hole density of 35 to 45 hpi, the hole density of the third high pressure water jet bar is higher than the hole density of the first high pressure water jet bar and recommended higher than the hole density of the second high pressure water jet beam.

According to a recommended embodiment variant is worked in the hydraulic solidification with a water jet, in particular with a high-pressure water jet bar, which is characterized by a hole diameter or nozzle bore diameter of 0.08 to 0.25 mm, preferably from 0.08 to 0.15 mm, preferably from 0.09 to 0.13 mm, for example, 0.12 mm distinguished. Expediently, all high-pressure water-jet beams of the hydraulic consolidation have the aforementioned hole diameter or the aforementioned nozzle bore diameter. According to a preferred embodiment of the invention, the first high-pressure water jet bar in the conveying direction of the nonwoven web has a larger hole diameter than the following high-pressure water jet bar or as the subsequent high-pressure water jet bar. Preferably, the first high-pressure water jet bar has a hole diameter of 0.10 to 0.18 mm, preferably 0.12 to 0.16 mm and for example 0.14 mm. Conveniently, the in Conveying direction second high-pressure water jet bar a hole diameter of 0.08 to 0.16 mm, preferably from 0.10 to 0.14 mm and for example 0.12 mm. If a third high pressure water jet bar is provided, it is recommended that it has finer nozzles or smaller hole diameters than the first high pressure water jet bar.

It is within the scope of the invention that in the hydraulic solidification or in the high-pressure water jet bar with a water pressure of over 120 bar, is advantageously carried out over 150 bar. The first high-pressure water jet device in the conveying direction of the nonwoven web or the first high-pressure water jet bar in the conveying direction is recommended to be operated with a water pressure of more than 220 bar, preferably more than 250 bar. According to a preferred embodiment, the second high-pressure water jet device or the second high-pressure water jet beam in the conveying direction is also operated with a water pressure of more than 220 bar, preferably more than 250 bar. The first high pressure water jet device in the conveying direction or the first high pressure water jet bar in the conveying direction is preferably provided on one side of the nonwoven web while the second high pressure water jet device in the conveying direction or the second high pressure water jet beam in the conveying direction is arranged on the opposite side of the nonwoven web. If at least one downstream high-pressure water jet device or at least one downstream high-pressure water jet beam is provided in the conveying direction of the nonwoven web, this or this is expediently operated with a water pressure of over 120 bar to 220 bar. This downstream high-pressure water jet bar or these downstream high-pressure water jet bars are used primarily for smoothing the nonwoven surfaces.

The hydraulic consolidation according to the invention can be carried out in an inline process or in an off-line process. In in-line operation, the hydraulic consolidation takes place continuously after mechanical needling or preferably after pre-moistening. In offline operation, the pre-bonded nonwoven web is first stored, for example rolled up and later supplied to the hydraulic consolidation or the pre-wetting and the hydraulic consolidation.

It is within the scope of the invention that the hydraulically consolidated nonwoven web is dried. According to one embodiment of the invention, the hydraulically consolidated nonwoven web is laterally stretched and / or thermostabilized after or during drying. In the case of transverse stretching, temperatures in the range of room temperature up to the softening temperature of the plastic or slightly more expedient. In thermostabilizing, the temperatures are between the softening point and the melting temperature of the plastic.

A very preferred embodiment of the invention is characterized in that the endverfestigte and dried and optionally transversely stretched nonwoven web has a basis weight of more than 130 g / m ^2, preferably of more than 150 g / m ^2, preferably of more than 180 g / m ² and particularly preferably greater than 200 g / m ² . The inventive method is particularly suitable for nonwoven webs or spunbonded nonwovens with higher basis weights.

The invention also provides an apparatus for producing spunbonded filaments, in particular made of thermoplastic material, wherein a spinning device is provided for spinning the filaments, wherein a cooling device for cooling the filaments and an adjoining stretching device for stretching or for aerodynamic stretching the filaments and a storage device for filing the filaments to the nonwoven web is provided
wherein at least one needle device or needle machine is present, with which the nonwoven web is preconsolidated by mechanical needling, wherein after filing the filaments to the nonwoven web and before the mechanical needling of the nonwoven web, a liquid medium in the nonwoven web can be introduced
and wherein at least one water jet device is provided, with which the nonwoven web is hydrodynamically or hydraulically endverfestigbar and wherein the water jet treatment for hydraulic final consolidation takes place from the top and from the bottom of the nonwoven web.

The water jet device is thus configured with the proviso that the water jet treatment of the nonwoven web from the top and from the bottom of the nonwoven web can be done. It is within the scope of the invention that a pre-moistening device for pre-moistening the non-woven web is arranged in front of the water-jet device.

The emerging from the spinning filaments are according to a particularly preferred embodiment of the invention according to the Reicofil III process ( DE-PS 196 203 79 ) or according to the Reicofil IV method ( EP-A 1 340 843 ). It is within the scope of the invention that the transition region between the cooling device or cooling chamber and the drawing device is designed to be closed and that no air is supplied except for the supply of cooling air in the cooling chamber in this transition region. It is within the scope of the invention that a closed cooling chamber is used. Closed cooling chamber means that the Cooling chamber is formed to the supply of cooling air to the environment completed. According to a particularly preferred embodiment of the invention, the filaments are cooled with the same air or cooling air in the cooling device and then stretched in the drawing device. In other words, essentially the cooling air supplied in the cooling chamber is also used for aerodynamic stretching of the filaments in the drawing device. A particularly recommended embodiment of the invention is characterized in that the entire unit of cooling device and drawing device is designed to be closed and, except for the supply of cooling air in the cooling chamber, no further air is supplied to this unit.

The invention is based on the finding that with the method according to the invention and with the device according to the invention spun nonwovens can be produced with relatively low energy input, which are characterized by optimum properties. The spunbonded webs have excellent strength or delamination resistance with low-energy production of the spunbonded nonwovens. In particular, the hydraulic or hydrodynamic consolidation can be operated with minimized energy use. The device according to the invention is compared to the known from practice devices with a smaller number of water jet beams or high pressure water jet beams and is thus constructed little complicated and expensive. The inventive method is particularly suitable for spunbonded nonwovens with higher basis weights from 100 g / m ² and especially from 150 g / m ² . The process according to the invention also brings particular advantages for spunbonded nonwovens which have filaments with low titres. It should also be emphasized that the method according to the invention and the device according to the invention can be operated at relatively low cost.

Fig. 1

einen Vertikalschnitt durch einen ersten Teil der erfindungsgemäßen Vorrichtung,

Fig. 2

einen Vertikalschnitt durch einen zweiten Teil der Vorrichtung (nicht zur Erfindung gehörend) und

Fig. 3

den Gegenstand nach Fig. 2 in einer erfindungsgemäßen Ausführungsform.

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 first part of the device according to the invention,

Fig. 2

a vertical section through a second part of the device (not belonging to the invention) and

Fig. 3

the object after Fig. 2 in an embodiment of the invention.

The figures show an apparatus for the production of spunbonded filaments, which are preferably made of thermoplastic material. The filaments are spun with a spinning device or Spinnerette 1 and are then introduced into a cooling chamber 2, in which the filaments are cooled with cooling air. The cooling chamber 2 is divided in the embodiment into two cooling sections 2a and 2b. In addition to the cooling chamber 2, an air supply cabin 8 is arranged, which is divided into an upper cabin section 8a and a lower cabin section 8b. From the two cabin sections 8a, 8b expediently cooling air with different convective heat removal capability is supplied. Preferably, cooling air of different temperature can be supplied from the two cabin sections 8a and 8b. The filaments can be acted upon in the two cooling sections 2a and 2b each with cooling air of different temperature and / or different amount and / or different humidity.

To the cooling chamber 2 includes a drawing device 4, which expediently and in the embodiment consists of an intermediate channel 3 and a subsequent to the intermediate channel 3 Unterziehkanal 5. According to a preferred embodiment and in the embodiment, the stretching device 4 is followed by a laying device 6 which has at least one diffuser 13, 14. In the exemplary embodiment, two diffusers are provided, namely a first diffuser 13 and an adjoining second diffuser 14. According to the recommended embodiment and in the exemplary embodiment according to FIG Fig. 1 an ambient air inlet gap 15 is provided between the first diffuser 13 and the second diffuser 14.

Appropriately, and in the embodiment, a continuously moving Ablagesiebband 7 for filing the filaments to the nonwoven web 11 is disposed below the laying device 6. According to a particularly preferred embodiment and in the embodiment according to Fig. 1 is provided in the region of the cooling chamber 2 and the drawing device 4 no air supply from the outside, apart from the supply of cooling air for cooling the filaments in the cooling chamber 2. Preferably and in the embodiment according to Fig. 1 takes place in the entire aggregate of cooling chamber 2 and drawing device 4 apart from the said air supply no further air supply from the outside. It is a so-called closed system. According to a variant embodiment and in the embodiment according to Fig. 1 takes place in the entire aggregate of cooling chamber 2, stretching device 4 and laying device 6 apart from the above-described air supply and the air supply through the ambient air inlet gap 15 no further air supply instead.

In the embodiment according to Fig. 1 For example, the filaments emerging from the second diffuser 14 are deposited on the laying screen belt 7 to the nonwoven web 11. Appropriately, and in the embodiment is located in this storage area for the filaments under the air-permeable Ablagesiebband 7 a suction device 19, the air sucks from below through the Ablagesiebband 7. According to embodiment according to Fig. 1 is located in the conveying direction of the nonwoven web behind the aforementioned storage area or suction a compacting device 9, which here consists of two outlet rollers 10, 12, which are suitably heated. The outlet rollers 10, 12 are not mandatory.

The Fig. 2 shows a second section of the device. This embodiment according to Fig. 2 does not belong to the invention. After depositing the filaments on the Ablagesiebband 7 and possibly after passing through the compacting device 9, the nonwoven web leaves the Ablagesiebband 7 and then the nonwoven web 11 is passed through a needle device 16 (needle machine) in which the nonwoven web 11 is mechanically pre-consolidated by needling. The nonwoven web 11, which has been preconsolidated in this way, is then fed to a water jet device 17 in which the nonwoven web 11 is hydraulically or hydrodynamically finally compacted. Before the final consolidation, the nonwoven web 11 is pre-moistened with a pre-moistening device 18. The pre-moistening device 18 is expediently and according to the exemplary embodiment Fig. 2 formed as transversely to the conveying direction of the nonwoven web 11 arranged water jet beam. The water jet beam is operated in contrast to the downstream high-pressure water jet beams 20, 21, 25 and 26 only with low water pressure.

In the embodiment according to Fig. 2 is worked with a water jet beam as Vorbefeuchtungseinrichtung 18 and four high-pressure water jet beams 20, 21, 25 and 26 as a water jet device 17 for hydrodynamic or hydraulic final consolidation. The water jet beam of the pre-wetting device 18 expediently has a nozzle bore diameter from 0.08 to 0.15 mm, preferably from 0.10 to 0.14 mm and, for example, a nozzle bore diameter of 0.12 mm. This water jet beam has recommended a hole density or nozzle bore density of 35 to 45 hpi, in particular a hole density of 40 hpi. The water jet beam of the pre-wetting device 18 is expediently operated with a water pressure of 5 to 120 bar, preferably with a water pressure of 20 to 110 bar and for example with a water pressure of 100 bar.

The two high-pressure water jet beams 20, 21 of the water jet device 17 preferably have a nozzle bore diameter of 0.08 to 0.16 mm. The first high pressure water jet beam 20 is characterized by a preferred embodiment of the invention by a hole density or nozzle bore seal smaller than 40 hpi, preferably less than 30 hpi and for example 25 hpi. The second high-pressure water jet bar 21 has in comparison to a larger hole density, preferably a hole density greater than 25 hpi, for example, a hole density of 30 hpi. The first and second high-pressure water jet beams 20, 21 are expediently operated at a water pressure above 220 bar. The water pressure of the two downstream high pressure water jet bars 25 and 26 is preferably between 130 and 220 bar. The two high-pressure water jet bars 25 and 26 primarily act on near-surface filaments and serve to smoothen the nonwoven web surfaces.

After the hydraulic final consolidation, the nonwoven web 11 is expediently dried. In this case, the residual water content is removed from the Wasserstrahlendverfestigung.

In the Fig. 3 an embodiment of the device according to the invention is shown. Here takes place between the filing of the filaments or between the outlet rollers 10, 12 and the needle device 16, the application of a liquid medium to the nonwoven web. For this purpose, a device 22 is provided with which the liquid medium is applied to the nonwoven web 11 from above. Below the nonwoven web 11 or below the Ablagesiebbandes 7 a suction device 23 is arranged, with which the applied liquid from the device 22 is sucked into the nonwoven web 11. Preferably, and in the exemplary embodiment, this suction device 23 has a suction slot 24 arranged transversely to the conveying direction of the nonwoven web 11. In this embodiment, with the application of a liquid medium can be dispensed with the pre-moistening before hydrodynamic final consolidation. That is why in Fig. 3 the optional pre-moistening device 18 is shown with dot-dash lines.

Claims (15)

1. A method for the manufacture of spunbonded fabrics from filaments, in particular of thermoplastic plastic, wherein
   the filaments are spun on at least one spinning device, are subsequently cooled and stretched and afterwards are deposited on a depositing rack to form a fleece web (11), wherein
   the fleece web (11) is initially consolidated by means of mechanical needling, wherein after the filaments have been deposited to form the fleece web (11), and before the mechanical needling of the fleece web (11), a fluid medium is introduced into the fleece web (11), wherein
   the fleece web (11) is then finally consolidated by means of hydrodynamic or hydraulic consolidation, and wherein
   the finally consolidated fleece web (11) has a weight per unit area of more than 80 g/m², preferentially more than 100 g/m².
2. The method in accordance with Claim 1, wherein a hydrophilic fluid medium is deployed as the fluid medium.
3. The method in accordance with Claim 2, wherein the fluid medium is introduced into the fleece web (11) as a quantity of 0.2 to 25%, preferentially as a quantity of 0.3 to 20%, and preferably as a quantity of 0.4 to 15%, with reference to the weight of the dry fleece web (11), i.e. the weight of a dry surface section of the fleece web (11).
4. The method in accordance with one of the Claims 1 to 3, wherein the mechanical needling of the fleece web (11) takes place with a perforation density of less than 70 E/cm².
5. The method in accordance with one of the Claims 1 to 4, wherein the fleece web (11) is initially wetted after the mechanical needling and before the hydraulic consolidation, i.e. the final consolidation.
6. The method in accordance with one of the Claims 1 to 5, wherein the water jet treatment during the hydraulic consolidation, i.e. the final consolidation, is undertaken from both the upper face and also the lower face of the fleece web (11).
7. The method in accordance with Claim 6, wherein the water jet treatment is executed with at least one high-pressure water jet bar (20, 21) above the upper face of the fleece web, and with at least one high-pressure water jet bar (20, 21) below the lower face of the fleece web (11).
8. The method in accordance with one of the Claims 1 to 7, wherein work with the hydraulic consolidation, i.e. final consolidation, is conducted with a plurality of high-pressure water jet bars (20, 21), and wherein the high-pressure water jet bar (20, 21) with the highest hydraulic consolidation effort has a proportion of at least 33%, preferentially a proportion of at least 40%, of the total hydraulic consolidation effort.
9. The method in accordance with one of the Claims 1 to 8, wherein the total hydraulic consolidation effort is less than 1 kWh/kg, preferentially less than 0.8 kWh/kg.
10. The method in accordance with one of the Claims 1 to 9, wherein in the hydraulic consolidation work is conducted with a water jet device (17), in particular with at least one high-pressure water jet bar (20, 21) which has a hole density of less than 40 hpi, preferentially less than 35 hpi, and preferably less than 30 hpi.
11. The method in accordance with one of the Claims 1 to 10, wherein in the hydraulic consolidation/final consolidation work is conducted with a water jet device (17), in particular with at least one high-pressure water jet bar (20, 21) which has a hole diameter of 0.08 to 0.25 mm, preferentially of 0.08 to 0.16 mm, and preferably of 0.10 to 0.16 mm.
12. The method in accordance with one of the Claims 1 to 11, wherein in the hydraulic consolidation work is conducted with a water jet device (17), in particular with at least one high-pressure water jet bar (20), which operates with a water pressure of more than 220 bar, and wherein preferentially at least one downstream high-pressure water jet bar (21) is provided, which is operated with a water pressure of between 130 and 220 bar.
13. The method in accordance with one of the Claims 1 to 12, wherein the finally consolidated fleece web (11) has a weight per unit area of more than 130 g/m², preferentially of more than 150 g/m².
14. A device for the manufacture of spunbonded fabrics from filaments, in particular of thermoplastic plastic, in particular for the execution of a method in accordance with one of the Claims 1 to 11, wherein
    a spinning device is provided for the spinning of the filaments, wherein a cooling device, or cooling chamber (2) is provided for the cooling of the filaments, and an adjacent stretching device (4) is provided for the stretching of the filaments, as is a depositing rack for the deposition of the filaments to form the fleece web (11), wherein
    furthermore at least one needle device (16) is present, with which the fleece web (11) can be initially consolidated by means of mechanical needling, wherein after the deposition of the filaments to form the fleece web (11), and before the mechanical needling of the fleece web (11), a fluid medium can be introduced into the fleece web (11), and wherein
    at least one water jet device (17) is provided, with which the fleece web (11) can be finally consolidated hydraulically, and wherein the water jet treatment for the final hydraulic consolidation is undertaken from the upper face and from the lower face of the fleece web (11).
15. The device in accordance with Claim 14, wherein an initial wetting device (18) is arranged upstream of the water jet device (17) for the initial wetting of the fleece web (11).

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