Method and apparatus for manufacturing nonwoven fabric from fibers

Abstract

The invention relates to a method for producing a nonwoven fabric from fibers. Continuous filaments are produced from thermoplastic by at least one meltblown spinneret. Also pulp fibers are produced by at least one fiber splitting device. At least one short fiber air stream is produced from the pulp fibers in the fiber splitting device, which is guided through an outlet channel and discharged from the outlet channel and flows with an initial volume flow V1 and a flow direction S1 towards the direction of a gas-permeable laying screen belt. The continuous filaments from the at least one meltblown spinneret flow as filament air stream with an initial volume flow V2 towards the direction of the short fiber air stream. The filament air stream and the short fiber air stream meet in a contact zone above the laying screen belt and are laid as a continuous filament-short fiber mixture in a laying area on the laying screen belt into a nonwoven fabric or nonwoven fiber web. In the laying area of the fibers or the continuous filament-short fiber mixture, air or process air is sucked through the laying screen belt from below with a volume flow V4. The volume flow V4 is greater than the sum of the volume flows V1 and V2.

Description

Technical Field

[0001] This invention relates to a method for manufacturing nonwoven fabrics from fibers, wherein continuous filaments are produced from thermoplastic material through at least one meltblown spinneret, preferably at least two, and pulp staple fibers are produced through at least one fiber splitting device, in which at least one short fiber airflow is generated from the pulp staple fibers. The continuous filaments from the at least one meltblown spinneret flow as filament airflow, and the continuous filaments and pulp staple fibers are laid in a laying area on a laying screen belt to form a nonwoven fabric or nonwoven fiber web. The invention also relates to an apparatus for manufacturing nonwoven fabrics from fibers. Within the scope of this invention, the term fiber refers to both continuous filaments and staple fibers. Continuous filaments differ from staple fibers due to their almost infinite length, while staple fibers have significantly smaller lengths, for example, from 0.1 mm to 60 mm. Nonwoven fabrics comprising at least continuous filaments, or meltblown continuous filaments, and staple fibers, or pulp staple fibers, can be manufactured using the method or apparatus according to the invention. Background Technology

[0002] The methods and apparatus of the type described at the beginning are essentially known from practice in various embodiments. Nonwoven fabrics containing pulp staple fibers are characterized by very high liquid absorption capacity. These pulp staple fiber-based nonwoven fabrics are used, for example, as absorbent cloths, such as wiping cloths. The liquid can be water or an aqueous liquid. However, in the manufacture of nonwoven fabrics containing pulp staple fibers, it has been shown that there is a conflict between the high liquid absorption capacity of the nonwoven fabric and sufficient stability or strength. To stabilize or mechanically stabilize the nonwoven fabric, it is known to use a mixture of continuous filaments and pulp staple fibers. Here, the continuous filaments are essentially responsible for the strength or stability of the nonwoven fabric, while the pulp staple fibers ensure the liquid absorption capacity of the resulting product. However, improvements are still needed in optimizing the trade-off between liquid absorption capacity and mechanical strength in these nonwoven fabrics composed of continuous filaments and pulp staple fibers. Furthermore, it has been shown that the uniformity of the distribution of continuous filaments and pulp staple fibers in the final product needs to be improved in methods known in practice. There is also room for improvement in this regard, because even with a relatively low content of continuous filaments, a satisfactory trade-off can be achieved between the mechanical strength and liquid absorption capacity of nonwoven fabrics when the distribution of continuous filaments and pulp staple fibers is very uniform. Summary of the Invention

[0003] Therefore, the technical problem of the present invention is to provide a method of the type described at the beginning, which can produce nonwoven fabrics from continuous filaments or meltblown continuous filaments and short fibers or pulp short fibers, which has the advantage of an optimized trade-off between strength or stability and liquid absorption capacity, and in particular, a high uniformity of distribution of continuous filaments and pulp short fibers. Furthermore, the technical problem of the present invention is to provide an apparatus for manufacturing such nonwoven fabrics.

[0004] To address this technical problem, the present invention teaches a method for manufacturing nonwoven fabrics from fibers, wherein continuous filaments are produced from thermoplastic plastic through at least one meltblown spinneret, preferably at least two meltblown spinnerets, and pulp short fibers are also produced through at least one fiber decomposition device, in which at least one short fiber airflow is generated from the pulp short fibers, the short fiber airflow is guided through and discharged from the outlet channel, and flows toward a breathable laying screen belt with an initial volumetric flow rate V1 and a flow direction S1;

[0005] The continuous filaments from the at least one meltblown spinneret flow as a filament airflow in the direction of the short fiber airflow with an initial volumetric flow rate V2;

[0006] The filament airflow and the short fiber airflow converge in the contact area above the laying screen belt and are laid as a continuous filament-short fiber mixture in the laying area of ​​the laying screen belt to form a nonwoven fabric or nonwoven fiber web.

[0007] In the fiber or continuous filament-short fiber blend laying area, air or process air is drawn from below through the laying screen belt at a volumetric flow rate V4, wherein the volumetric flow rate V4 is greater than the sum of the volumetric flow rates V1 and V2.

[0008] Within the scope of the method according to the invention, molten plastic filaments are generated through the meltblown spinneret and extruded into a rapid flow of forced air. The forced air is also suitably discharged from the meltblown spinneret, and is preferably warm or hot forced air. The filament air flow, comprising the generated continuous filaments and the forced air, then flows from the at least one meltblown spinneret or each meltblown spinneret towards the short fiber air flow. The design of the meltblown spinneret, particularly regarding the discharge of the molten plastic filaments and the forced air, will be explained in more detail below.

[0009] According to the invention, continuous filaments are produced from thermoplastic plastics. Preferably, within the scope of the method according to the invention, the continuous filaments are produced from at least one polyolefin. The at least one polyolefin is suggested to be polypropylene and / or polyethylene, preferably polypropylene. Essentially, the continuous filaments can also be made from other thermoplastic plastics, such as polyesters, for example polyethylene terephthalate or polyamides, and mixtures of the above thermoplastic plastics. It is suggested that the average filament diameter of the continuous filament or meltblown continuous filament is between 0.2 μm and 15 μm, preferably between 0.5 μm and 12 μm, and more preferably between 0.5 μm and 10 μm.

[0010] Within the scope of this invention, the term "pulp" specifically refers to fibrous materials based on pulp or cellulose. Suitablely, solid pulp is used within the scope of the method according to the invention. The term "solid pulp" specifically refers to dried materials based on pulp or cellulose. Particularly preferably, within the scope of the invention, a fiber web composed of solid pulp is used, and it is dissociated into short pulp fibers by said at least one fiber dissociation device. The pulp used within the scope of the method according to the invention is preferably pretreated. The short pulp fibers produced in said at least one fiber dissociation device suitably have a length or average length of 0.05 mm to 5 mm, preferably 0.1 mm to 4 mm, particularly preferably 0.1 mm to 3 mm.

[0011] According to a preferred embodiment of the invention, the fiber decomposition device is a saw mill. According to the invention, in the fiber decomposition device, a short fiber airflow is generated from pulp short fibers, which is guided through an outlet channel and discharged from the outlet channel at an initial volumetric flow rate V1 and flows in the direction of the air-permeable laid-out screen belt in the flow direction S1. The outlet channel is suitably part of or connected to the fiber decomposition device. Within the scope of the invention, the initial volumetric flow rate V1 refers to the volumetric flow rate of the short fiber-air mixture directly or immediately following its discharge from the outlet channel.

[0012] According to a preferred embodiment of the invention, the breathable laying screen belt is a continuously movable and breathable laying screen belt, particularly a continuously circulating laying screen belt.

[0013] According to the invention, the resulting continuous filament flows from the at least one meltblown spinneret as a filament airflow in the direction of a short fiber airflow with an initial volumetric flow rate V2. Here, the initial volumetric flow rate V2 specifically refers to the volumetric flow rate of the filament airflow that exists directly or immediately below the meltblown spinneret after the continuous filament is subjected to blowing air.

[0014] According to the invention, air or process air is drawn in, or at least in, the laying area of ​​the fibers or a continuous filament-short fiber mixture by a laying screen belt. For this purpose, suitably, at least one suction device or suction blower is arranged below the laying screen belt, particularly below the laying area. According to the invention, the volumetric flow rate V4 drawn in by the laying screen belt is greater than the sum of volumetric flow rates V1 and V2, therefore: V4 > (V1 + V2). In a particularly preferred embodiment of the method according to the invention, the volumetric flow rate V4 corresponds to between 1.05 and 30 times, preferably between 5 and 25 times, and more preferably between 10 and 20 times, the sum of volumetric flow rates V1 and V2.

[0015] According to a particularly preferred embodiment of the invention, at least two meltblown spinnerets, particularly two continuous filaments, are present. The continuous filaments particularly preferably flow from the second meltblown spinneret as a second filament airflow in the direction of the short fiber airflow with an initial volumetric flow rate V3. Here, the initial volumetric flow rate V3 specifically refers to the volumetric flow rate of the filament airflow directly or immediately below the meltblown spinneret or the second meltblown spinneret after the continuous filaments are subjected to blowing air. Very particularly preferred is that the volumetric flow rate V4 is greater than the sum of the volumetric flow rates V1, V2, and V3, thus particularly applicable is V4 > (V1 + V2 + V3). According to a particularly preferred embodiment of the method of the invention, the volumetric flow rate V4 corresponds to between 1.05 and 30 times, preferably between 5 and 25 times, and more preferably between 10 and 20 times, the sum of the volumetric flow rates V1, V2, and V3.

[0016] It has been shown that the filament airflow flows before the short fiber airflow in the conveying direction F of the laying screen belt, while the second filament airflow preferably flows after the short fiber airflow in the conveying direction F of the laying screen belt.

[0017] Within the scope of this invention, the filament airflow flows at least partially or locally with respect to its flow direction S2 at an angle α1 to the flow direction S1 of the short fiber airflow. Suitably, the second filament airflow flows at least partially or locally with respect to its flow direction S3 at an angle α2 to the flow direction S1 of the short fiber airflow. A particularly preferred embodiment of the invention is characterized in that angles α1 and / or α2 are greater than 10°, particularly preferably greater than 20°, and very particularly preferably greater than 25°. Thus, within the scope of this invention, two filament airflows flow toward the short fiber airflow. For the filament airflow to flow at an angle α1 or α2 with respect to its flow direction S2 or S3 and the flow direction S1 of the short fiber airflow, within the scope of this invention, it specifically refers to the flow vector of the filament airflow extending at least partially or locally with the flow direction S1 or flow vector of the short fiber airflow at an angle α1 or α2. Within the scope of this invention, the terms flow direction and flow vector specifically refer to the average flow direction or flow vector of the corresponding flow.

[0018] Particularly preferably within the scope of the invention, the at least one filament airflow, and in particular multiple filament airflows, flow at an angle α1 or α2 with respect to their flow direction S2 or S3, at least in the contact area or shortly before the contact area, with respect to the flow direction S1 of the short fiber airflow. Thus, angles α1 and α2 specifically refer to the angle of inclination at which the filament airflow intersects the short fiber airflow in the contact area. According to a preferred embodiment of the invention, the at least one filament airflow, and in particular two filament airflows, flow along the entire flow path—particularly in a straight or substantially straight line—from the respective meltblown spinneret at an angle α1 or α2 with respect to the flow direction S1 of the short fiber airflow to the contact area. Particularly preferably, the at least one filament airflow, or each of the filament airflows and / or the short fiber airflows, flows from the meltblown spinneret or outlet channel to the contact area without a guiding medium.

[0019] As described above, angles α1 and / or α2 are greater than 10°, particularly preferably greater than 20°. It has been shown that angles α1 and / or α2 are greater than 25°, preferably greater than 30°, more preferably greater than 35°, for example greater than 40°. It is suggested that the values ​​of angles α1 and / or α2 be between 10° and 75°, preferably between 20° and 70°, particularly preferably between 25° and 65°, and very particularly preferably between 30° and 65°, for example between 35° and 60°. Within the scope of the invention, angles α1 and α2 have the same value, such that the two filament airflows intersect the short fiber airflow or the central short fiber airflow symmetrically in the contact area, particularly on both sides. However, it is also possible in principle that angles α1 and α2 have different values.

[0020] According to a preferred embodiment of the method according to the invention, the short fiber airflow flows from the outlet channel or the end of the outlet channel with respect to its flow direction S1 perpendicular to or substantially perpendicular to the surface of the screen belt on which the screen belt is laid. Therefore, the flow direction S1 of the short fiber airflow is oriented particularly perpendicular to or substantially perpendicular to the surface of the permeable screen belt. Within the scope of the invention, this specifically means that the flow vector of the short fiber airflow extends perpendicular to or substantially perpendicular to the plane of the screen belt surface.

[0021] Within the scope of this invention, secondary air is drawn in the gap between the short fiber airflow and the long filament airflow and / or in the gap between the short fiber airflow and the second long filament airflow. The secondary air is hereby specifically expressed as a volumetric flow rate V. sek Inhalation, of which V sek Suitable is the total volumetric flow rate of the total intake secondary air. Preferably, it is: V4 ≥ (V1 + V2 + V...) sek ) and / or V4≥(V1+V2+V3+V sek It is suggested that V4 correspond to volumetric flow rates V1, V2, and V... sek The sum and / or volumetric flow rates V1, V2, V3, V sek The sum of the amounts is between 1 and 30 times, preferably between 5 and 25 times, and more preferably between 10 and 20 times. Within the scope of this invention, the term "secondary air" specifically refers to air additionally drawn in by the flow motion of the filament airflow and / or the short fiber airflow, which does not correspond to the blown air from the meltblown spinneret and does not correspond to the air discharged from the outlet channel along with the pulp short fibers. Within the scope of this invention, the blown air from the meltblown spinneret and the air discharged from the outlet channel along with the pulp short fibers are specifically referred to as primary air. Furthermore, within the scope of this invention, the term "air" also includes gaseous or fluid mixtures similar to air.

[0022] Suitably, the short fiber airflow is accelerated in the outlet channel, particularly by a blower from the fiber disintegration device. Therefore, according to a preferred embodiment, the fiber disintegration device has a blower supplying air to it. Within the scope of the invention, the airflow used to generate the short fiber airflow in the fiber disintegration device is generated by the disintegration process and / or by the blower. According to a preferred embodiment of the invention, the fiber disintegration device is a saw mill. The airflow used to generate the short fiber airflow is then preferably generated by a grinding process in the saw mill and / or by a blower from the saw mill. According to a preferred embodiment, the short fiber airflow accelerated in the outlet channel is discharged from the outlet channel at an initial volumetric flow rate V1.

[0023] According to a particularly preferred embodiment of the invention, the at least one meltblown spinneret has a plurality of nozzle openings arranged in a row, and preferably has two air inflow gaps extending on both sides parallel to the row of nozzle openings and inclined toward the nozzle openings, from which blown air is discharged. Suitably, the at least two, particularly two, meltblown spinnerets are designed in this way. Within the scope of the invention, having a plurality of nozzle openings in a row in a meltblown spinneret specifically refers to a meltblown spinneret having only one row of nozzle openings. Such a meltblown spinneret is also referred to as a single-row nozzle. Suitably, each meltblown spinneret has at least two, particularly two, air inflow gaps extending on both sides parallel to the row of nozzle openings. Within the scope of the invention, air inflow gaps extending parallel on both sides specifically refer to air inflow gaps whose longitudinal extensions extend parallel to the longitudinal extensions of the row of nozzle openings. Furthermore, it is recommended that the air inflow gaps be inclined toward the nozzle openings or the row of nozzle openings. This specifically enables the continuous filament sheet to be extruded from the air inlet gap by a planar flow of forced air, either laterally or in the opposite direction, impacting the extruded filament at an angle of attack. The angle of attack of the forced air relative to the flow direction of the produced continuous filament is preferably less than 30°, more preferably less than 20°. Preferably, the continuous filament from the two air inlet gaps of the meltblown spinneret is uniformly or symmetrically supplied with forced air. However, in principle, it is also possible to apply forced air to the continuous filament non-uniformly or asymmetrically in terms of the temperature and / or volumetric flow rate of the forced air through the two air inlet gaps of the meltblown spinneret.

[0024] According to another preferred embodiment of the invention, the at least one meltblown spinneret has a plurality of nozzle openings arranged in multiple rows, wherein preferably, each nozzle opening is provided with an air inlet or its own air inlet, from which blown air is discharged. Such a meltblown spinneret having multiple rows of nozzle openings for discharging molten plastic filaments is also called a multi-row nozzle. Within the scope of the invention, the at least two, particularly two, meltblown spinnerets are designed in this manner. Each nozzle opening of the meltblown spinneret has an air inlet or its own air inlet, which, within the scope of the invention, specifically means that the corresponding air inlet is directly provided to or can be directly provided to the nozzle opening. Within the scope of the invention, the air inlet of the meltblown spinneret surrounds and is arranged, in particular, coaxially with the corresponding nozzle opening. Blown air then flows out from the air inlet provided to the nozzle opening, suitably parallel to the plastic melt or the molten plastic filament, and suitably sheaths the produced filament.

[0025] According to another preferred embodiment of the invention, the at least one meltblown spinneret has a plurality of outlet openings and air inlet openings arranged in multiple rows in the form of nozzle openings, wherein the outlet openings, or nozzle openings and air inlet openings, are preferably arranged in a regular and / or irregular pattern spaced apart from each other, and wherein preferably at least 90% of the air inlet openings, particularly each air inlet opening, are provided with at least two nozzle openings and / or preferably at least 90% of the nozzle openings, particularly each nozzle opening, are provided with at least two air inlet openings. Within the scope of the invention, the at least two, particularly two, meltblown spinnerets are designed in this way. This embodiment of the invention is characterized in that the corresponding nozzle openings discharging the plastic melt or molten plastic filaments are not directly provided with their own air inlet openings. Instead, each nozzle opening is preferably provided with at least two air inlet openings. Within the scope of this embodiment, forced air is discharged from the air inlet openings. Preferably, the nozzle openings are configured such that only the polymer melt is discharged from the nozzle openings, and the polymer melt is discharged from the nozzle openings, particularly without a forced air flow directly provided to or coaxially discharged with the corresponding nozzle opening. Suitably, only the blown air exits from the air inlet opening. Within the scope of this preferred embodiment, a portion of the outlet opening of the meltblown spinneret is constructed in the form of a nozzle opening, and a portion or another portion of the outlet opening is constructed in the form of an air inlet opening. Within the scope of this embodiment, it is recommended that the distance between directly adjacent outlet openings of the meltblown spinneret in at least one nozzle direction is the same or substantially the same throughout the nozzle. Furthermore, preferably, the proportion of nozzle openings in the total number of outlet openings is between 10% and 50%, more preferably between 12% and 45%, and more preferably between 15% and 40%.

[0026] According to a preferred embodiment of the invention, if at least two, particularly two, meltblown spinnerets are present, preferably, the two or all meltblown spinnerets are constructed identically in terms of nozzle opening and air inlet opening or air inlet gap. However, in principle, at least two different meltblown spinnerets can also be combined within the scope of the method according to the invention. Furthermore, preferably, the outlet opening, particularly the nozzle opening and / or air inlet opening, of the meltblown spinneret is constructed to be circular or abbreviated.

[0027] The present invention recognizes that a method can be provided by the specific flow conditions according to the invention, and particularly by the ratio of the sum of the initial volumetric flow rates of the short fiber airflow and the filament airflow to the volumetric flow rate drawn in through the laying screen belt. This method allows the manufacture of nonwoven fabrics from continuous filaments and pulp short fibers, characterized by a very high uniformity in the distribution of the continuous filaments and pulp short fibers, and particularly by an optimized trade-off between the stability or strength of the nonwoven fabric and its liquid absorption capacity. A particularly advantageous result is achieved here, wherein the filament airflows (respectively) flow at an angle to the flow direction of the short fiber airflow, and particularly preferably symmetrically, the two filament airflows flow at an angle to the central short fiber airflow on both sides. The continuous filament-short fiber mixture laid on the laying screen belt is suitably a matrix comprising continuous filaments in which the pulp short fibers are embedded.

[0028] According to a preferred embodiment of the method according to the invention, the continuous filaments of the at least one filament airflow, preferably multiple filament airflows, are sprayed with water between the meltblown spinneret and the laying screen, particularly on the side of the filament airflow away from the short fiber airflow. For spraying water onto the continuous filaments, preferably one or a corresponding water nozzle is provided, which is particularly arranged on the side of the corresponding filament airflow away from the short fiber airflow. Thus, suitably, the at least one water nozzle or the multiple water nozzles are located outside the filament airflow. Within the scope of the invention, the water nozzle is disposed to the corresponding meltblown spinneret and preferably arranged below the meltblown spinneret in the filament flow direction, particularly directly below the meltblown spinneret. Therefore, the continuous filaments are sprayed with water immediately after exiting the meltblown spinneret, particularly immediately after exiting the meltblown spinneret. In this way, targeted cooling of the produced continuous filaments can be achieved.

[0029] Preferably, the airflow containing 0.0138 kg to 0.0833 kg of short pulp fibers per kg of air, more preferably 0.0222 kg to 0.0694 kg, and more preferably 0.0277 kg to 0.05 kg, is discharged from the outlet channel. It is suggested that the airflow containing more than 0.0138 kg of short pulp fibers per kg of air, more preferably more than 0.0222 kg, and more preferably more than 0.0277 kg, is discharged from the outlet channel. Suitably, the content of short pulp fibers per kg of air can be controlled and / or adjusted by the speed of the fiber decomposition device, particularly by the feed speed of the fiber decomposition device.

[0030] Preferably, at least one or more filament air streams containing 0.002 kg to 0.5 kg, more preferably 0.01 kg to 0.25 kg, more preferably 0.015 kg to 0.12 kg, and particularly preferably 0.018 kg to 0.1 kg of continuous filament per kg of air are discharged from the meltblown spinneret. It is suggested that at least one or more filament air streams (each) containing more than 0.002 kg, more preferably more than 0.01 kg, more preferably more than 0.015 kg, and particularly preferably more than 0.018 kg of continuous filament per kg of air are discharged from the meltblown spinneret. Furthermore, within the scope of the invention, multiple filament air streams, particularly two filament air streams, containing the same amount of continuous filament per kg of air are discharged from the meltblown spinneret. According to an alternative embodiment of the method according to the invention, multiple filament air streams, particularly two filament air streams, containing different amounts of continuous filament per kg of air are discharged from the meltblown spinneret. The content of continuous filaments per kg of air in the filament airflow exiting the meltblown spinneret, according to a proposed embodiment of the invention, is adjusted by controlling and / or regulating the mass flow of the thermoplastic and / or the blown air exiting from the air inflow gap or air inflow opening of the meltblown spinneret. According to a particularly preferred embodiment of the invention, the content of continuous filaments in the laid nonwoven fabric is between 10 and 35% by weight, preferably between 15 and 30% by weight, and more preferably between 20 and 28% by weight.

[0031] As described above, according to an advantageous embodiment of the invention, the short fiber airflow is accelerated in the outlet channel by a blower of the fiber breaking device. Preferably, the air drawn in by the blower of the fiber breaking device is pretreated. Particularly preferably, the pretreated air drawn in by the blower has a relative humidity greater than 65% at 28°C.

[0032] Within the scope of this invention, the outlet channel is height-adjustable relative to the surface of the screen belt on which the screen belt is laid. Suitably, the distance 'a' between the end of the outlet channel and the surface of the screen belt is between 200 mm and 1000 mm, preferably between 300 mm and 750 mm, more preferably between 400 mm and 600 mm, and particularly preferably between 460 mm and 530 mm. Therefore, the outlet channel or the end of the outlet channel is height-adjustable relative to the surface of the screen belt on which the screen belt is laid in these areas. Very particularly preferably, by adjusting the height of the outlet channel relative to the surface of the screen belt on which the screen belt is laid, the amount of secondary air drawn in is controllable and / or adjustable. Within the scope of the method according to the invention, it is recommended to set the height of the outlet channel as follows: V4 ≥ (V1 + V2 + V... sek ) and / or V4≥(V1+V2+V3+V sekThe amount of secondary air drawn in here specifically refers to the amount of secondary air drawn in between the short fiber airflow and at least one, preferably two filament airflows. Within the scope of the invention, the term "exit channel end" specifically refers to the end of the outlet channel facing the laid-out screen belt. Preferably, the wall of the outlet channel in the region of the outlet channel end is designed such that the internal cross-section of the outlet channel end is configured to be constant, divergent, or convergent. In this way, the subsequent mixing of continuous filaments and pulp short fibers in the contact zone can be influenced, particularly. Within the scope of the invention, the distance α between the outlet channel end and the screen belt surface is measured, particularly perpendicular to the screen belt surface. Due to the controllability and / or adjustability of the amount of secondary air drawn in, the flow conditions, particularly regarding the secondary air supply, can be functionally and reliably influenced. Furthermore, within the scope of the invention, the position of the contact zone is also settable or adjustable through the height adjustment or height adjustability of the outlet channel or the outlet channel end, particularly in conjunction with angles α1 and / or α2. Therefore, the design of the wall of the outlet channel in the region at the end of the outlet channel, and preferably by a constant design of the internal cross-section of the wall of the outlet channel in the region at the end of the outlet channel, can advantageously influence the blending of continuous filaments and pulp staple fibers.

[0033] According to the invention, filament airflow, preferably multiple or two filament airflows and short fiber airflows, converge in the contact zone above the laying screen belt. It is proposed that the filament airflow and short fiber airflow mix in this contact zone. According to a preferred embodiment of the invention, the continuous filament-short fiber mixture flows from the contact zone to the laying screen belt as a homogeneous or substantially homogeneous mixture. By converging the short fiber airflow and filament airflow under the flow conditions and preferred angles according to the invention, optimized mixing and distribution of pulp short fibers and continuous filaments can be achieved within the scope of the invention, thereby immediately following the contact zone, the homogeneous or substantially homogeneous continuous filament-short fiber mixture flows to the laying screen belt and is laid into a nonwoven fabric or nonwoven fiber web. Advantageously, the continuous filament-short fiber mixture flows from the contact zone to the laying screen belt or laying area perpendicular or substantially perpendicular to the screen belt surface in its flow direction.

[0034] Within the scope of this invention, a short fiber airflow is directed or conveyed with at least 50 kg / h / m, particularly at least 75 kg / h / m, preferably at least 100 kg / h / m, and especially preferably at least 200 kg / h / m of pulp short fibers relative to the width of the laid-up screen belt. Within the scope of this invention, the width of the laid-up screen belt specifically refers to the maximum width of the laid-up screen belt transverse to, and particularly perpendicular to, its longitudinal extension or conveying direction. Within the scope of this invention, preferably at least two, particularly at least three, and preferably at least four fiber separation devices, each having associated blowers and / or outlet channels, are arranged along the width of the laid-up screen belt. In this way, pulp short fibers or a short fiber airflow can be supplied uniformly across the entire width of a laid-up screen belt with a width of at least 1 meter, particularly at least 2 meters, preferably at least 3 meters, and more preferably at least 4 meters.

[0035] A particularly preferred embodiment of the method according to the invention is characterized in that the nonwoven fabric or nonwoven fiber web is cured by at least one calender, wherein preferably, an embossed pattern is introduced into the nonwoven fabric or nonwoven fiber web by said at least one calender. It is recommended that the curing be performed "online" by said at least one calender. Within the scope of the invention, this specifically refers to curing by said at least one calender after the continuous filament-staple fiber mixture has been laid into a nonwoven fabric or nonwoven fiber web. According to an alternative preferred embodiment of the method according to the invention, the nonwoven fabric or nonwoven fiber web is cured "offline" by said at least one calender. Within the scope of the invention, this specifically refers to the nonwoven fabric or nonwoven fiber web being removed from the laying screen and wound after being laid on the laying screen, and only at a later point in time being re-unrolled and fed to said at least one calender.

[0036] It is suggested that the at least one calender has at least one pair of calender rolls through which the nonwoven fabric or nonwoven fiber web is preferably pressed under a pressing pressure. Suitably, one of the calender rolls of the calender is a smooth roll with a smooth outer surface and / or one of the calender rolls of the calender has an embossed pattern on its outer surface. According to a preferred embodiment of the invention, the calender or the pair of calender rolls is temperature-controlled. Within the scope of the invention, the temperature of the calender rolls is preferably below the melting point of the thermoplastic material of the continuous filament. Preferably, within the scope of the method according to the invention, the calender roll temperature is between 50°C and 150°C. Furthermore, within the scope of the invention, the linear pressure of the calender rolls is between 10 daN / cm and 120 daN / cm.

[0037] Particularly preferred is that the embossed pattern is uninterrupted, and the embossed area of ​​the basic geometric shape of the embossed pattern is 20 mm². 2 Up to 50mm 2Within the range, preferably within 25mm 2 Up to 45mm 2 Within the range, more preferably within 30mm 2 Up to 40mm 2 Within the range, and particularly preferably within 32.5mm 2 up to 37.5mm 2 Within the scope of this invention, the basic geometry of the pattern refers specifically to the basic geometry of the repeating elements of the embossed pattern. In this regard, it can be understood that the basic geometry of the pattern or the repeating elements are preferably of the same size or substantially the same size, thus resulting in a regular embossed pattern. Within the scope of this invention, an uninterrupted embossed pattern is a honeycomb structure in which the basic geometry of the pattern or its repeating elements is suitably hexagonal or regular hexagonal. The embossed pattern then preferably consists of a plurality of adjacent regular hexagons of the same size, wherein the inner surface of the hexagons preferably forms the unpressed portion of the embossed pattern.

[0038] According to another preferred embodiment of the invention, the embossed pattern has interruptions and is particularly composed of a plurality of non-interconnected elements, preferably dots and / or lines, wherein each element suitably has a diameter of less than 2 mm. 2 Preferably less than 1.5mm 2 More preferably, less than 1.1 mm 2 A material smaller than 0.55mm is preferred. 2 The pressing area. Within the scope of this invention, it is also possible to combine an uninterrupted embossed pattern with an embossed pattern having interruptions.

[0039] Advantageously, the height of the basic geometric shape or element of the embossed pattern is between 0.3 mm and 2.0 mm, preferably between 0.4 mm and 1.8 mm, and more preferably between 0.5 mm and 1.6 mm. The height of the basic geometric shape refers here to the height difference or average height difference between the embossed surface and the unembossed area of ​​the embossed pattern. Furthermore, within the scope of the invention, the proportion of the embossed surface of the embossed pattern to the total surface area of ​​the nonwoven fabric or nonwoven fiber web is between 2.5% and 25%, preferably between 5% and 15%, and more preferably between 5.25% and 12.5%.

[0040] Furthermore, regarding the above-mentioned design of the embossed pattern, it can be understood that the corresponding rolls of the calender roll pair with the embossed pattern have complementary embossed patterns on their outer surfaces. The calender or calender rolls particularly have a pressing area percentage or pressing area of ​​2.5% to 25%, preferably 5% to 15%, and more preferably 5.25% to 12.5%.

[0041] To address the aforementioned technical problem, the present invention further teaches an apparatus for manufacturing nonwoven fabrics from fibers, particularly by the above-described method, wherein the apparatus has at least one meltblown spinneret, preferably at least two meltblown spinnerets, for producing continuous filaments from thermoplastic plastics.

[0042] It also includes at least one fiber decomposition device for producing pulp short fibers and an outlet channel for guiding the pulp short fibers or short fiber airflow.

[0043] The device has at least one breathable laying screen for laying pulp staple fibers and continuous filaments as a mixture of continuous filament-staple fibers into a nonwoven fabric or nonwoven fiber web, and is provided with at least one suction device that allows air or process air to be drawn through the laying screen in the laying area of ​​the fibers or the continuous filament-staple fiber mixture.

[0044] According to a preferred embodiment, the device has at least two, particularly two, meltblown spinnerets. Preferably, the first meltblown spinneret is arranged before the outlet channel in the conveying direction of the laid screen belt, and the second meltblown spinneret is arranged after the outlet channel in the conveying direction of the laid screen belt. Within the scope of the invention, the at least one meltblown spinneret, preferably the at least two, or the two meltblown spinnerets are arranged at an angle to the outlet channel. The angle of inclination between the meltblown spinneret and the outlet channel is suitably (each) at least 10°, preferably at least 20°, more preferably at least 25°. It is also preferable that the angle of inclination between the meltblown spinneret and the outlet channel is (each) at least 30°, particularly preferably at least 35°, for example at least 40°. It is suggested that the inclination angles (at least between the meltblown spinneret and the outlet channel, preferably between the two meltblown spinnerets and the outlet channel) be between 10° and 75°, preferably between 20° and 70°, particularly preferably between 25° and 65°, very particularly preferably between 30° and 65°, for example between 35° and 60°. In this way, the filament airflow can flow from the meltblown spinneret towards the direction of the laying screen belt at an angle α1 or α2 to the flow direction S1 of the short fiber airflow and in the direction of the short fiber airflow. It is suggested that the inclination angles between the meltblown spinneret and the outlet channel are settable or adjustable.

[0045] Preferably, the outlet channel is configured to be height-adjustable relative to the surface of the screen belt on which the screen belt is laid. It has been shown that the distance 'a' between the end of the outlet channel and the surface of the screen belt is in the range of 200 mm to 1000 mm, preferably between 300 mm to 750 mm, more preferably between 400 mm to 600 mm, and particularly preferably between 460 mm to 530 mm.

[0046] According to a preferred embodiment of the device of the invention, the fiber decomposition apparatus has at least one blower for accelerating the flow of pulp short fibers or short fiber air in the outlet channel.

[0047] The present invention further teaches a nonwoven fabric composed of a continuous filament-short fiber blend, which is manufactured according to the above-described method and / or using the above-described equipment. The thickness of the nonwoven fabric is suggested to be in the range of 0.1 mm to 3 mm, preferably 0.2 mm to 2 mm, and more preferably 0.3 mm to 1.5 mm. Within the scope of the present invention, the thickness of the nonwoven fabric specifically refers to the maximum thickness of the nonwoven fabric extending transversely to, particularly perpendicularly to, or substantially perpendicularly to its plane, and especially after a preferably configured curing or calendering step.

[0048] This invention is based on the understanding that nonwoven fabrics comprising continuous filaments and pulp staple fibers can be manufactured by the method according to the invention, which meet all requirements not only in terms of stability or strength but also in terms of their liquid absorption capacity.

[0049] In this regard, the measures according to the invention enable an optimized trade-off between the strength and liquid absorption capacity of the nonwoven fabric. The flow conditions and preferred arrangement of the meltblown spinneret and outlet channel for the pulp staple fibers, according to the invention, particularly allow for optimized mixing of continuous filaments and pulp staple fibers, resulting in a nonwoven fabric with a very uniform distribution of continuous filaments and pulp staple fibers. In this way, a nonwoven fabric meeting all requirements can be provided with a relatively low proportion of continuous filaments. Furthermore, it should be emphasized that the measures according to the invention are relatively uncomplicated, and the method according to the invention is therefore highly economical. This also applies to the equipment according to the invention. Attached Figure Description

[0050] The invention will now be described in more detail with the aid of the accompanying drawings, which show only one embodiment. In the schematic diagram:

[0051] Figure 1 A vertical sectional view of the apparatus according to the invention for performing the method according to the invention is shown;

[0052] Figure 2 A bottom view of a first embodiment of a meltblown spinneret according to the present invention is shown;

[0053] Figure 3 It shows according to Figure 2 A vertical sectional view of the object;

[0054] Figure 4 A bottom view of a second embodiment of the meltblown spinneret according to the present invention is shown;

[0055] Figure 5 A bottom view of a third embodiment of a meltblown spinneret according to the present invention is shown;

[0056] Figure 6A A partial top view of a nonwoven fabric with an embossed pattern according to the present invention is shown;

[0057] Figure 6B It shows according to Figure 6A The cross section along AA. Detailed Implementation

[0058] Figure 1 An apparatus for manufacturing a nonwoven fabric 1 from fibers according to the present invention is shown. Continuous filaments are produced from thermoplastic material through two melt-blown spinnerets 2, 3. Within the scope of the invention and in this embodiment, the thermoplastic material may be polypropylene. Figure 1 As can be seen, pulp, preferably, and in this embodiment, solid pulp 19, is used to produce short pulp fibers through at least one fiber-decomposing device 4. The fiber-decomposing device 4 is suitably, and in this embodiment, a saw mill. According to the invention, at least one short fiber airflow 5 is generated from the pulp short fibers in the fiber-decomposing device 4. The short fiber airflow 5 is preferably, and in this embodiment, accelerated in the outlet channel 6 by a blower 7 of the fiber-decomposing device 4. The blower 7 suitably, and in this embodiment, supplies air to the fiber-decomposing device 4. The airflow used to generate the short fiber airflow 5 is generated by the grinding process in the fiber-decomposing device 4 or the saw mill, and by the blower 7, within the scope of the invention and in this embodiment.

[0059] According to the invention, the accelerated short fiber airflow 5 is discharged from the outlet channel 6 with an initial volumetric flow rate V1. Within the scope of the invention, the initial volumetric flow rate V1 specifically refers to the volumetric flow rate of the short fiber airflow 5 directly or immediately following its discharge from the outlet channel 6. The short fiber airflow 5 flows toward the laying screen belt 8 in a flow direction S1 (which is preferably, and in this embodiment, oriented perpendicular to or substantially perpendicular to the surface of the permeable laying screen belt 8). The permeable laying screen belt 8 is suitably, and in this embodiment, constructed as a continuously circulating laying screen belt 8.

[0060] The continuous filaments produced by the meltblown spinnerets 2 and 3 suitably, and in this embodiment, flow as filament airflows 9 and 10 from the meltblown spinnerets 2 and 3 toward the short fiber airflow 5 with an initial volumetric flow rate V2 or V3. The initial volumetric flow rate V2 or V3 specifically refers to the volumetric flow rate present directly or immediately below the meltblown spinnerets 2 and 3 after the continuous filaments are loaded with blower air.

[0061] Within the scope of the invention and in this embodiment, the first filament airflow 9 flows ahead of the short fiber airflow 5 in the conveying direction F of the laying screen belt 8. The filament airflow 9 flows at an angle α1 to the flow direction S1 of the short fiber airflow 5 with respect to its flow direction S2. The second filament airflow 10 flows after the short fiber airflow 5 in the conveying direction F of the laying screen belt 8. The second filament airflow 10 flows at an angle α2 to the flow direction S1 of the short fiber airflow 5 with respect to its flow direction S3. Therefore, the filament airflows 9 and 10 preferably, and in this embodiment, flow from both sides of the central short fiber airflow 5 at an angle α1 or α2 toward the short fiber airflow 5. Within the scope of the invention, angles α1 and α2 are preferably greater than 20°, and particularly preferably greater than 25°. In the embodiment according to the drawings, angles α1 and α2 may each be about 30°. Preferably, and within the scope of the embodiments, angles α1 and α2 have the same value or substantially the same value.

[0062] Suitably, and in this embodiment, the filament airflows 9, 10 and the short fiber airflow 5 converge in the contact area 11 above the laying screen belt 8 and are laid as a continuous filament-short fiber mixture 12 in the laying area 13 on the laying screen belt 8 to form a nonwoven fabric 1 or a nonwoven fiber web. Preferably, and in this embodiment, the filament airflows 9, 10 flow at an angle α1 or α2 with respect to their flow direction S2 or S3 relative to the flow direction S1 of the short fiber airflow 5 in the region of the contact area 11, or immediately before the contact area. Thus, within the scope of the invention and in this embodiment, angles α1 and α2 specifically refer to the angle of inclination at which the filament airflows 9, 10 intersect with the short fiber airflow 5 in the contact area 11. Preferably, and in this embodiment, the two filament airflows 9, 10 flow at an angle α1 or α2 with respect to their flow direction S2 or S3 relative to the flow direction S1 of the short fiber airflow 5 along the entire flow path from the respective meltblown spinnerets 2, 3 to the contact area 11. Suggestedly and in this embodiment, the filament airflows 9 and 10 flow in a straight line or substantially in a straight line. Furthermore, preferably and according to... Figure 1 In this embodiment, the filament airflows 9 and 10 flow symmetrically toward the short fiber airflow 5 and intersect symmetrically with the short fiber airflow 5 in the contact area 11. The two filament airflows 9 and 10 and the short fiber airflow 5 preferably, and in this embodiment, flow from the meltblown spinneret 2 and 3 or from the outlet channel 6 to the contact area 11 without a guiding medium.

[0063] It is recommended, and in this embodiment, that secondary air is drawn in through the gap between the long filament airflows 9 and 10 and the short fiber airflow 5. The secondary air here is specifically expressed as a volumetric flow rate V. sek Inhalation, of which V sekSuitablely, it is the total volumetric flow rate of the total intake secondary air. Furthermore, according to the invention, in or at least in the laying area 13 of the fiber or continuous filament-short fiber mixture 12, air or process air is drawn in from below through the laying screen belt 8 at a volumetric flow rate V4. For this purpose, within the scope of the invention and in this embodiment, a suction device 16 or suction blower is provided below the laying screen belt 8, particularly below the laying area 13. Preferably, the volumetric flow rate V4 is greater than the sum of volumetric flow rates V1, V2, and V3. More preferably, the volumetric flow rate V4 is greater than the sum of volumetric flow rates V1, V2, V3, and V... sek The sum of .

[0064] According to a preferred embodiment of the invention, meltblown spinnerets 2 and 3 each have a plurality of nozzle openings 17 arranged in a row, from which molten plastic filaments are preferably extruded, within the scope of the method according to the invention. Two air inflow gaps 18 preferably extend on either side parallel to the row of nozzle openings 17. This... Figure 2 and Figure 3 As can be seen, the forced-air air preferably exits from the air inlet gap 18. The plastic filament extruded from the nozzle opening 17 is suitably extruded into the forced-air airflow. The meltblown spinnerets 2 and 3 are within the scope of the invention and in this embodiment according to... Figure 2 and Figure 3 It has only a single row of nozzle openings 17, and is configured as a single row of nozzles in this respect. The air inflow gap 18 extends on both sides parallel to the row of nozzle openings 17. Within the scope of the invention, this specifically refers to the longitudinal extension of the air inflow gap 18 extending parallel to the longitudinal extension of the row of nozzle openings 17. Figure 2 Air inflow gap 18 is preferably, and within the scope of the embodiment, according to Figure 2 and Figure 3 Inclined toward the direction of nozzle opening 17 or toward the direction of the row of nozzle openings 17. The forced-air flow or planar forced-air flow exiting the air inlet gap 18 is then loaded laterally at an angle of attack to extrude the continuous filament. Figure 3 ).

[0065] Figure 4 A bottom view of another preferred embodiment of the meltblown spinnerets 2 and 3 is shown. According to... Figure 4 In preferred embodiments of the meltblown spinnerets 2 and 3, a plurality of nozzle openings 17 arranged in multiple rows are provided, wherein each nozzle opening 17 is equipped with an air inlet opening 21, or its own air inlet opening 21, through which blown air is discharged. Such a meltblown spinneret having multiple rows of nozzle openings 17 for discharging molten plastic filaments is also called a multi-row nozzle. Preferably, and in accordance with... Figure 4 In one embodiment, each air inlet opening 21 is directly disposed to a specific nozzle opening 17. The air inlet opening 21 is preferably and according to... Figure 4 In this embodiment, the corresponding nozzle opening 17 is coaxially surrounded. In this way, the blown air flows out of the air inlet opening 21 provided to the corresponding nozzle opening 17, parallel and coaxial with the plastic melt or molten plastic filament.

[0066] Another preferred embodiment of meltblown spinnerets 2 and 3 is... Figure 5 As shown in the figure. The meltblown spinneret 2 or meltblown spinnerets 2, 3, according to this preferred embodiment, have a plurality of outlet openings arranged in multiple rows, in the form of nozzle openings 17 (in... Figure 5 (shown as an unfilled circle in the image) and air inlet opening 21 (in...) Figure 5 (shown as filled circles). Suitably and in this embodiment, the outlet opening, or nozzle opening 17, and the air inlet opening 21 are arranged spaced apart from each other in a regular pattern. Each nozzle opening 17 is provided with at least two air inlet openings 21. This specifically means that at least two airflow openings 21 are arranged directly adjacent to each nozzle opening 17. Furthermore, preferably and in this embodiment, at least two nozzle openings 17 are arranged directly adjacent to each air inlet opening 21. According to Figure 5 Within the preferred embodiment, only blown air is discharged from the air inlet opening 21. Preferably, the nozzle opening 17 is configured such that only the polymer melt is discharged therefrom, and the polymer melt is discharged from the nozzle opening 17, particularly in the absence of a blown air flow directly disposed to or coaxially separated from the nozzle opening 17. Suitably and according to Figure 5 In this embodiment, a portion of the outlet opening of the meltblown spinneret 2 or meltblown spinnerets 2, 3 is constructed in the form of a nozzle opening 17, and a portion or another portion of the outlet opening is constructed in the form of an air inflow opening 21. Within the scope of this embodiment and in this embodiment, the distances between directly adjacent outlet openings of the meltblown spinnerets in the longitudinal and transverse directions of the meltblown spinnerets 2, 3 are the same or substantially the same throughout the nozzles 2, 3.

[0067] Within the scope of the invention and in this embodiment, on the side of the filament airflows 9 and 10 opposite to the short fiber airflow 5, water is sprayed between the meltblown spinnerets 2 and 3 and the laying screen belt 8. For this purpose, water nozzles 20 are provided, suitably and in this embodiment, arranged on the side of the respective filament airflows 9 and 10 opposite to the short fiber airflow 5. Therefore, it is recommended, and in this embodiment, that the water nozzles 20 are located on the outside of the filament airflows 9 and 10, and particularly preferably arranged in the filament flow direction below or directly below the meltblown spinnerets 2 and 3.

[0068] The amount of secondary air drawn in is controllable and / or adjustable within the range of the method according to the invention or preferably through the height adjustment of the outlet channel 6 or the end 14 of the outlet channel relative to the surface of the screen belt 8 using the device according to the invention. Proposedly, the height of the outlet channel 6 is set as follows, i.e., applicable is: V4 ≥ (V1 + V2 + V...). sek ) and / or V4≥(V1+V2+V3+V sek The outlet channel 6 is preferably configured to be height-adjustable relative to the surface of the screen belt 8 on which it is laid. The distance α between the outlet channel end 14 and the screen belt surface is suitably between 200 mm and 1000 mm, preferably between 300 mm and 750 mm. Within the scope of the invention, the distance α between the outlet channel end 14 and the screen belt surface is measured perpendicular to the screen belt surface. The wall of the outlet channel 6 in the region of the outlet channel end 14 is preferably, and in this embodiment, designed such that the outlet channel end 14 is divergently constructed in its internal cross-section. By the height adjustability or height adjustment of the outlet channel 6 and the design of the wall of the outlet channel 6 or the outlet channel end 14, within the scope of the invention, particularly in combination with the selection of angles α1 and α2, the position of the contact area 11 can be set or adjusted. Thus, the mixing of continuous filaments and pulp staple fibers can also be advantageously influenced.

[0069] Preferably, the continuous filament-staple fiber mixture 12 flows from the contact area 11 to the laying screen belt 8 as a uniform or substantially uniform mixture. Subsequently, suitably, the uniform continuous filament-staple fiber mixture 12 is laid in the laying area 13 on the laying screen belt 8 to form a nonwoven fabric 1 or a nonwoven fiber web. Suggestedly and according to... Figure 1 In one embodiment, the continuous filament-short fiber mixture 12 flows from the contact area 11 to the laying screen belt 8 and the laying area 13 with respect to its flow direction perpendicular or substantially perpendicular to the screen belt surface.

[0070] According to a preferred embodiment of the method of the present invention, and in this embodiment, the nonwoven fabric 1 is cured "in-line" by at least one calender 15. In this embodiment, the at least one calender 15 has at least one pair of calender rolls, through which the nonwoven fabric 1 is preferably cured under compression pressure. Furthermore, preferably, an embossed pattern is introduced into the nonwoven fabric 1 or the nonwoven fiber web by the at least one calender 15. For this purpose, at least one of the calender rolls of the calender 15 may have an embossed pattern on its outer surface.

[0071] Figure 6A A partial top view of a nonwoven fabric with an embossed pattern according to the present invention is shown. Figure 6B It shows according to Figure 6A The cross-section of the object along AA. Preferably, and according to Figure 6AIn this embodiment, the embossed pattern is constructed without interruption. The basic geometric shape or repeating element of the embossed pattern is preferably a regular hexagon, thus the embossed pattern preferably, and in this embodiment, consists of a plurality of adjacent regular hexagons of the same size, and in particular, is constructed as a honeycomb embossed pattern. Figure 6B As can be seen, the unpressed portion of the embossed pattern is appropriately formed on the inner surface of the hexagon.

[0072] It is recommended that the height h of the basic geometric shape or element of the embossed pattern be between 0.3mm and 2.0mm. Based on... Figure 6A and 6B In this embodiment, the height of the basic geometric shape or regular hexagon of the pattern is approximately 1.5 mm. The height h of the basic geometric shape refers to the height difference or average height difference between the pressed surface and the unpressed area of ​​the embossed pattern. Furthermore, within the scope of this invention, the proportion of the pressed surface of the embossed pattern in the total surface area of ​​the nonwoven fabric is between 2.5% and 25%, preferably between 5% and 15%. It should also be understood that the corresponding rollers of the calender roller pair with the embossed pattern have complementary embossed patterns on their outer surfaces.

Claims

1. A method for manufacturing a nonwoven fabric (1) from fibers, wherein, Continuous filaments are produced from thermoplastic through at least one meltblown spinneret (2), and pulp short fibers are also produced through at least one fiber decomposition device (4). In the fiber decomposition device (4), at least one short fiber airflow (5) is generated from the pulp short fibers. The short fiber airflow is guided through an outlet channel (6) and discharged from the outlet channel, flowing towards the breathable laying screen belt (8) with an initial volumetric flow rate V1 and a flow direction S1. The continuous filaments from the at least one meltblown spinneret (2) flow as the first filament airflow (9) in the direction of the short fiber airflow (5) with an initial volumetric flow rate V2. The first filament airflow (9) and short fiber airflow (5) converge in the contact area (11) above the laying screen belt (8) and are laid as a continuous filament-short fiber mixture (12) in the laying area (13) on the laying screen belt to form a nonwoven fabric (1) or a nonwoven fiber web. In the laying area (13) of the fiber or continuous filament-short fiber mixture (12), air is drawn from below through the laying screen belt (8) at a volume flow rate V4, wherein the volume flow rate V4 is greater than the sum of the initial volume flow rates V1 and V2, the outlet channel (6) is height adjustable relative to the screen belt surface of the laying screen belt (8), and the distance (a) between the outlet channel end (14) and the screen belt surface is between 200 mm and 1000 mm.

2. The method according to claim 1, wherein, Continuous filaments are produced from thermoplastics using at least two meltblown spinnerets.

3. The method according to claim 1, wherein, The air mentioned is process air.

4. The method according to claim 1, wherein, There are at least two meltblown spinnerets, and the continuous filaments from the second meltblown spinneret flow as the second filament airflow (10) flows in the direction of the short fiber airflow (5) with an initial volumetric flow rate V3.

5. The method according to claim 4, wherein, The volumetric flow rate V4 is greater than the sum of the initial volumetric flow rates V1, V2 and V3.

6. The method according to claim 4, wherein, The first filament airflow (9) flows before the short fiber airflow (5) in the conveying direction (F) of the laying screen belt (8), and the second filament airflow (10) flows after the short fiber airflow (5) in the conveying direction (F) of the laying screen belt (8).

7. The method according to any one of claims 1 to 6, wherein, The first filament airflow (9) flows at least partially at an angle α1 to the flow direction S1 of the short fiber airflow (5) with respect to its flow direction S2.

8. The method according to claim 4, wherein, The first filament airflow (9) flows at least partially with respect to its flow direction S2 at an angle α1 to the flow direction S1 of the short fiber airflow (5), and the second filament airflow (10) flows at least partially with respect to its flow direction S3 at an angle α2 to the flow direction S1 of the short fiber airflow (5), wherein the angle α1 and / or the angle α2 is greater than 10°.

9. The method according to claim 8, wherein, The angles α1 and / or α2 are greater than 20°.

10. The method according to claim 8, wherein, The angles α1 and / or α2 are greater than 25°.

11. The method according to any one of claims 1 to 6, wherein, The short fiber airflow (5) from the outlet channel (6) or the end of the outlet channel (14) flows perpendicular to the surface of the screen belt (8) with respect to its flow direction S1.

12. The method according to any one of claims 1 to 6, wherein, Secondary air is drawn in the gap between the short fiber airflow (5) and the first filament airflow (9) and / or in the gap between the short fiber airflow (5) and the second filament airflow (10).

13. The method according to any one of claims 1 to 6, wherein, The short fiber airflow (5) is accelerated in the outlet channel (6).

14. The method according to claim 13, wherein, The short fiber airflow is accelerated by the blower (7) of the fiber decomposition device (4).

15. The method according to any one of claims 1 to 6, wherein, The at least one meltblown spinneret has a plurality of nozzle openings (17) arranged in a row.

16. The method according to claim 15, wherein, The at least one meltblown spinneret has two airflow gaps (18) extending on both sides parallel to the nozzle openings (17) and inclined toward the nozzle openings (17), from which blown air is discharged.

17. The method according to any one of claims 1 to 6, wherein, The at least one meltblown spinneret has a plurality of nozzle openings arranged in multiple rows (17).

18. The method according to claim 17, wherein, Each nozzle opening (17) is equipped with its own air inlet opening (21) from which blown air is discharged.

19. The method according to any one of claims 1 to 6, wherein, The at least one meltblown spinneret has a plurality of outlet openings and air inlet openings (21) arranged in multiple rows in the form of nozzle openings (17), the outlet openings and air inlet openings (21) being arranged in a regular and / or irregular pattern.

20. The method according to claim 19, wherein, The outlet opening and the air inlet opening (21) are arranged in a regular and / or irregular pattern, spaced apart from each other.

21. The method according to claim 19, wherein, Each air inlet opening (21) is provided with at least two nozzle openings (17) and / or each nozzle opening (17) is provided with at least two air inlet openings (21).

22. The method according to any one of claims 1 to 6, wherein, Between the meltblown spinneret and the laying screen belt (8), water is sprayed onto the continuous filaments of the first filament airflow (9).

23. The method according to any one of claims 1 to 6, wherein, Water is sprayed onto the continuous filaments of each filament airflow on the side of the filament airflow away from the short fiber airflow (5) between the meltblown spinneret and the laying screen belt (8).

24. The method according to any one of claims 1 to 6, wherein, An airflow (5) containing 0.0138 kg to 0.0833 kg of pulp short fiber per kg of air is discharged from the outlet channel (6).

25. The method according to any one of claims 1 to 6, wherein, An airflow (5) containing 0.0222 kg to 0.0694 kg of pulp short fiber per kg of air is discharged from the outlet channel (6).

26. The method according to any one of claims 1 to 6, wherein, An airflow (5) containing 0.0277 kg to 0.05 kg of pulp short fiber per kg of air is discharged from the outlet channel (6).

27. The method according to any one of claims 1 to 6, wherein, The first filament air stream (9), with a continuous filament content of 0.002 kg to 0.5 kg per kg of air, is discharged from the meltblown spinneret.

28. The method according to any one of claims 1 to 6, wherein, The first filament air stream (9), with a continuous filament content of 0.01 kg to 0.25 kg per kg of air, is discharged from the meltblown spinneret.

29. The method according to any one of claims 1 to 6, wherein, Each of the aforementioned filament air streams, with a continuous filament content of 0.018 kg to 0.1 kg per kg of air, is discharged from the meltblown spinneret.

30. The method according to any one of claims 1 to 6, wherein, The distance (a) between the end of the outlet channel (14) and the surface of the screen belt is between 300 mm and 750 mm. The amount of secondary air drawn in is controllable and / or adjustable due to the height adjustment of the outlet channel (6) relative to the surface of the screen belt on which the screen belt (8) is laid.

31. The method according to claim 30, wherein, The distance (a) between the end of the outlet channel (14) and the surface of the screen belt is between 400 mm and 600 mm.

32. The method according to claim 30, wherein, The distance (a) between the end of the outlet channel (14) and the surface of the screen belt is between 460 mm and 530 mm.

33. The method according to any one of claims 1 to 6, wherein, The short fiber airflow (5) guides or transports at least 50 (kg / h) / m of pulp short fibers relative to the width (b) of the laid screen belt (8).

34. The method according to any one of claims 1 to 6, wherein, The short fiber airflow (5) guides or transports at least 75 (kg / h) / m of pulp short fibers relative to the width (b) of the laid screen belt (8).

35. The method according to any one of claims 1 to 6, wherein, The short fiber airflow (5) guides or transports at least 100 (kg / h) / m of pulp short fibers relative to the width (b) of the laid screen belt (8).

36. The method according to any one of claims 1 to 6, wherein, The short fiber airflow (5) guides or transports at least 200 (kg / h) / m of pulp short fibers relative to the width (b) of the laid screen belt (8).

37. The method according to any one of claims 1 to 6, wherein, The nonwoven fabric (1) or nonwoven fiber web is cured by at least one calender (15).

38. The method according to claim 37, wherein, The embossed pattern is introduced into the nonwoven fabric (1) or nonwoven fiber web by means of at least one calender (15).

39. The method according to claim 38, wherein, The embossed pattern is constructed without interruption, and the embossed area of ​​the basic geometric shape of the embossed pattern is 20 mm². 2 Up to 50mm 2 Within the range.

40. The method according to claim 39, wherein, The embossed pattern has a basic geometric shape with an embossed area of ​​25mm². 2 Up to 45mm 2 Within the range.

41. The method according to claim 39, wherein, The embossed pattern has a basic geometric shape with an embossed area of ​​30mm². 2 Up to 40mm 2 Within the range.

42. The method according to claim 39, wherein, The embossed pattern has a basic geometric shape with an embossed area of ​​32.5 mm². 2 up to 37.5mm 2 Within the range.

43. The method according to claim 38, wherein, The embossed pattern has interruptions and is composed of multiple non-connected elements, each element having a diameter of less than 2mm. 2 The area of ​​suppression.

44. The method according to claim 43, wherein, Each element has a diameter of less than 1.5 mm. 2 The area of ​​suppression.

45. The method according to claim 43, wherein, Each element has a diameter of less than 1.1 mm. 2 The area of ​​suppression.

46. ​​The method according to claim 43, wherein, Each element has a diameter of less than 0.55 mm. 2 The area of ​​suppression.

47. The method according to claim 43, wherein, The embossed pattern consists of multiple unconnected dots and / or lines.

48. An apparatus for manufacturing a nonwoven fabric from fibers by the method according to any one of claims 1 to 47, wherein, The device has at least one meltblown spinneret (2) for producing continuous filaments from thermoplastics. There is also at least one fiber decomposition device (4) for producing pulp short fibers and an outlet channel (6) for guiding pulp short fibers or short fiber airflow (5). The device has at least one breathable laying screen (8) for laying pulp staple fibers and continuous filaments as a continuous filament-staple fiber mixture (12) into a nonwoven fabric (1) or a nonwoven fiber web. There is at least one suction device (16) that can draw air through the laying screen belt (8) in the laying area (13) of the fiber or continuous filament-short fiber mixture (12), and the outlet channel (6) is height adjustable relative to the screen belt surface of the laying screen belt (8), and the distance (a) between the end (14) of the outlet channel and the screen belt surface is between 200 mm and 1000 mm.

49. The device according to claim 48, wherein, The device has at least two meltblown spinnerets.

50. The device according to claim 49, wherein, The first meltblown spinneret (2) is arranged before the outlet channel (6) in the conveying direction of the laid screen belt (8), and the second meltblown spinneret (3) is arranged after the outlet channel (6) in the conveying direction of the laid screen belt (8).

51. A nonwoven fabric (1) made from a continuous filament-staple fiber mixture (12) according to any one of claims 1 to 47.

Images