Plant for producing nonwoven fabric

Abstract

An apparatus (100) is provided for producing nonwoven fabric comprising a dispensing unit including an outlet (10a) extending along a dispensing plane (100a) and configured to allow a plurality of filaments to be dispensed from the dispensing unit by Venturi effect forming a layer of filaments along or parallel to the dispensing plane (100a); a collecting surface (11) extending transversally to the dispensing plane (100a) downstream of the dispensing unit to collect the layer exiting the outlet (10a) so as to produce a nonwoven article; at least one plant for producing nonwoven fabric housed in the dispensing unit, extending along a main axis (1a) and a main plane (1b) transversal to the dispensing plane (100a) and configured to dispense toward the outlet (10a) a filament of the type chosen from among polymeric or cellulose or viscose along one or more dispensing directions (4a) transversal to the main plane (1b); in which the dispensing unit includes at least two plants distributed parallel to the main plane (1b) side-by-side of which only one is of the type chosen between spunbond and meltblown so that at least two distinct types of filaments dispensed from the plants are mixed simultaneously in the dispensing unit at the mouth of the outlet (10a) so that filaments of different types make one same layer only at the outlet of the dispensing unit.

Description

[0001] DESCRIPTION

[0002] PLANT FOR PRODUCING NONWOVEN FABRIC

[0003] The object of the present invention is a plant for producing nonwoven fabric of the type specified in the preamble to the first claim.

[0004] In particular, this invention relates to a plant comprising a spunbond spinneret, or a combination of spunbond and meltblown spinnerets, of the cuspid or multi-row coaxial type, suitable for allowing distribution of the polymeric fluid exiting from the plant in the form of extruded polymeric filaments to produce nonwoven fabric.

[0005] In addition, the invention also relates to a plant suitable for enabling extruded polymeric filaments to be combined with cellulose filaments to produce nonwoven fabric.

[0006] In addition, this invention relates to an article internally comprising layers of continuous polymeric filaments, possibly combined with cellulose or other synthetic materials in fibrous or particulate form, and the associated process for forming such an article, which can be used in filtration or, especially if the particles are liquid-absorbent, in absorbent sanitary articles.

[0007] As is known, nonwoven fabric, or NWF, is an industrial product similar to a fabric but obtained using processes other than weaving and knitting. For instance, inside a nonwoven fabric, the fibers have a random pattern, with no identifiable ordered structure whereas in a fabric, the fibers have two prevailing directions, orthogonal to each other, usually called weft and warp.

[0008] Currently, a plurality of products containing NWF are produced depending on the manufacturing technique used, mainly dictated by the use made of the product itself.

[0009] In particular, a distinction is made between high quality NWFs for sanitary products, and low quality NWFs used especially for Geotex.

[0010] From a technical point of view, nonwoven fabrics can be basically divided into spunlace, spunbond and cuspid or multirow coaxial meltblown fabrics.

[0011] The spunlace fabric undergoes processing that gives the material equidirectional resistance. Thanks to this property, to the possibility of being produced in different materials such as viscose, polyester, cotton, polyamide and microfiber, to the two possible finishes, i.e. smooth or perforated, and to the multitude of smooth or printed colors, spunlace is suitable both for the sanitary sector and for the automotive / cosmetic sectors, for industrial or single-use purposes.

[0012] Spunbond, usually made of polypropylene, is a nonwoven fabric that has numerous applications in the agricultural, sanitary, construction, furniture, mattress-making and other related sectors. By means of an appropriate treatment, it is possible to create a series of highly specific products for each sector: fluorescent, soft calendered, anti-mite, fireproof, antibacterial, antistatic, anti-UV and others. Numerous finishes can also be applied to spunbond products, such as printed, laminated, flexographic printed laminate and self-adhesive.

[0013] The production plants for spunbond nonwoven fabric essentially include at least one inlet pipe for the polymeric substance, a polymer extrusion head, a polymer dispenser, also known as breaker plate, and a spinneret suitable for producing the spunbond yarn true and proper that is deposited on a conveyor belt.

[0014] The elements mentioned are arranged in sequence, adjacent to one another in such a way as to allow processing of the polymer and distribution of the spunbond NWF.

[0015] In greater detail, the polymer inside the inlet pipe is pushed under pressure and at high temperatures, usually over 200°C, toward the extrusion head. Generally, in this regard, a pressure check is made, for example by means of a pressure gauge, to ensure continuity of the yarn being output and precision of the deposition process.

[0016] The extrusion head distributes the polymer along a distribution surface through which the molten polymer reaches the dispenser. Between the dispenser, or breaker plate, and the extrusion head, there is a filter consisting of a steel sheet of thickness usually varying between 0.8 and 1.6 mm and including fine meshes, for example, with nominal dimensions between 20 and 1 10 pm. Basically, therefore, the filter mentioned is a stretched net.

[0017] After passing inside the filter, the molten polymer enters the dispenser that accompanies the polymer toward the spinneret where the polymer is extruded into filaments constituting the spunbond NWF. In detail, the filter has the purpose of blocking polymer particles or pigments, that are not perfectly dissolved or are overly large and which, by entering the spinneret, could obstruct the extremely small NWF extrusion holes.

[0018] Meltblown NWF is made through specific spinnerets in order to achieve higher technical characteristics than the previously discussed NWFs. In fact, the meltblown fabric is characterized by fibers with high filtering power for both liquid and aeriform substances.

[0019] Meltblown nonwoven fabric production plants consist of a box that encloses the meltblown fiber manufacturing device and all the parts that are necessary for optimal functioning of the process.

[0020] Known cuspid type meltblown plants comprise an extrusion head, a cuspid-shaped dispenser, and an air blade.

[0021] Multi-row coaxial meltblown plants, instead, provide for stretching of the polymer coming out of tubes, arranged in rows, through the air which, in a coaxial manner, passes from the outside of the tube and pushes the fiber downwards.

[0022] In particular, the multi-row coaxial meltblown type plants comprise components defining coaxial holes, arranged in rows and suitable for accommodating at least part of the aforementioned tubes transiting coaxially inside the holes in such a way as to allow diffusion of polymeric fluid and, at the same time, also allow diffusion of the air or gas from at least some of the holes.

[0023] Usually, these plants include devices, called spin packs, including a plurality of different components suitable for interacting with one another. Usually, a spin pack consists of a spinneret and a diffusion device including one or more components called air plates.

[0024] In even greater detail, the spinnerets for the currently known spunbond and / or meltblown coaxial multi-row plants comprise a plate including first holes suitable for accommodating tubing configured to distribute polymeric fluid, and second holes separate from the first holes and suitable for allowing air or gas to pass, and a jig, separate or in one piece from the plate, including a plurality of third holes centered with respect to the first holes, in fluid passage connection with said second holes and suitable for accommodating part of the tubing and allowing, at the same time, passage of said air or gas.

[0025] The known art described comprises a number of drawbacks. Specifically, especially with regard to spunbond technology which, downstream of the spinneret, i.e. in a position after the exit of the filaments from the spinneret, usually provides nozzles suitable for hitting the filaments with jets of air for the purpose of cooling them. Cooling the filaments before deposition on a coil belt is fundamental because it prevents adjacent filaments from sticking together due to heat.

[0026] At the same time, however, the air jets cannot exert excessive pressure on the filaments as otherwise the filaments would risk being deflected from their exit trajectory, leading in any case to the filaments undesirably becoming mutually attached.

[0027] Added to this is the fact that, since the cooling nozzles are placed laterally to the filament exit trajectory, the reduced pressure with which the air hits the filaments means that the central filaments, being shielded by the lateral ones, cannot be cooled efficiently or at least similarly to the lateral filaments. Thus the technical problem represented by unintentional joining of filaments with loss of performance in terms of nonwoven fabric remains.

[0028] In addition to the above, it is evident that in order to ensure proper cooling of the filaments, it is necessary to increase the mutual distance, i.e. the spacing, between the output filaments. This implies that the currently known spinnerets cannot include a high density of holes or dispensing tubes with the consequence that high density fabric layers cannot be made.

[0029] In addition, the layers of nonwoven fabric made with the currently known spinnerets are not particularly high-performance when under traction in different directions.

[0030] In fact, while nonwoven fabrics made in this way are very robust along the plant’s main direction of extension, they are not so when perpendicular to that direction.

[0031] The consequence of this failing is, for example, highly impactful in the manufacture of diapers and wet wipes.

[0032] In fact, the above articles are normally made by overlapping a plurality of layers to form the complete layered structure of the item in question.

[0033] Specifically, a conventional diaper is generally made following a sequence (usually referred to as S, S, MB, MB, S) of layering in which there are two spunbond sheets, two meltblown sheets, and a further spunbond sheet; wipes have similarities although they also include intermediate portions that may include particulate materials.

[0034] In any case, the items just described, on account of how they are made, have a number of important drawbacks.

[0035] First, they are made by layering on a single belt, which implies a plurality of different passes and high lead times. Moreover, this aspect also implies higher costs resulting not only from the manufacturing method, but also from the fact that a greater number of layers increases the cost of the item.

[0036] In addition, some layers are double due to the fact that there are limitations regarding the density of the filament delivery holes, especially with the conventional spunbond spinnerets previously described. Therefore, it is necessary to make the spunbond part in two layers, i.e. in two separate stages and / or devices, typically a plurality of booths arranged in series each equipped with a containment chamber in which there is a spinneret of the type needed to make the desired layer.

[0037] And, as anticipated earlier, it is also known that some items may include particulate materials. The latter are widely used in absorbent structures for absorbent articles, for example for personal hygiene, such as disposable diapers for children, training pants for children or underwear for adult incontinence, which are designed to absorb and contain body exudates, especially urine, and in other items that retain humidity, such as wet wipes.

[0038] These absorbent articles comprise several layers which perform different functions, typically including a top sheet, a back sheet and, among the other layers, an absorbent core. The absorbent core must be able to absorb and retain liquid exudates for a prolonged period of time, such as overnight for a diaper, minimize re-wetting to keep the wearer dry, and avoid soiling clothing or sheets. Modern absorbent cores typically comprise absorbent structures composed of superabsorbent polymer (SAP) particles, also called absorbent gelling materials (AGM), and fibrous materials, which may be natural, such as cellulose fibers, modified natural, such as regenerated cellulose-based materials, or synthetic fibers, for instance viscose.

[0039] It is well known that absorbent structures can be formed "in-line" or "in-situ" on a converting line to form the complete absorbent article; see for example WO2022 / 120693A1 , which discloses an absorbent core for use in an absorbent article, comprising a liquid-permeable top cover layer, a bottom cover layer and a high-fill-coefficient core layer between the top and bottom cover layers, and first and second super-absorbent polymers which at least partially penetrate into the high-fill- coefficient core layer, in addition to adhesively-fixed cover layers. Furthermore, WO2014 / 001487 discloses particles embedded in a porous fabric and ultrasonically immobilized between the cover layers.

[0040] However, these approaches require that each of the article production lines, also known as converters, be equipped with appropriate handling systems for the addition of particles, as well as unwinding and joining systems for the preformed ribbons. Furthermore, formation of the absorbent core may limit the overall production volume.

[0041] As an alternative to forming the core in-line, composite absorbent ribbons comprising particles, such as super-absorbents, may be formed off-line at high production volumes, which may be delivered as so-called roll stocks to the conversion lines for forming articles to be packaged and / or combined with other elements to form the absorbent articles, thereby advantageously simplifying the conversion equipment and process and offering production cost advantages on account of the high production volumes.

[0042] In general, although forming absorbent structures off-line offers advantages over in-line production, for example a very high production volume from a single production unit, there is still a need to improve the economics and / or properties of the resulting absorbent structures. Furthermore, using adhesives in the absorbent structure complicates recycling, in particular that of factory waste, and can negatively impact consumers' perception of an unnecessary chemical.

[0043] In this situation, the technical task underlying the present invention is to devise a nonwoven fabric production plant that can substantially overcome at least part of the above-mentioned drawbacks. Within the scope of said technical task, it is an important object of the invention to obtain a nonwoven fabric production plant that enables density of the polymeric filament delivery holes in the plant, preferably of the spunbond type, to be increased. Accordingly, another important object of the invention is to design a nonwoven fabric production plant that enables layers of nonwoven fabric, normally made with several distinct spinnerets, to be made with a single spinneret.

[0044] An important task of the invention is therefore to design a nonwoven fabric production plant that can reduce the cost of producing a layer for a sanitary item such as a diaper, wet wipe or other similar items.

[0045] A further object of the invention is to design a nonwoven fabric production plant that enables layered articles to be made reducing the process steps and times needed to finalize the article.

[0046] Thus, a further task of the invention is to obtain a nonwoven fabric production plant that can combine different technologies, for example spunbond and meltblown, for producing the articles.

[0047] Yet another task of the invention is to obtain a nonwoven fabric production plant suitable for enabling extruded polymeric filaments to be combined with cellulose filaments in order to produce nonwoven fabric.

[0048] Therefore, a further object of the invention is to produce an article, within which are layered continuous polymeric filaments possibly combined with cellulose or other synthetic materials in fibrous or particulate form, and associated process for the manufacture of such an article, which can be applied in filtration or, especially if the particles are liquid absorbent, in absorbent hygienic articles. In particular, an additional task of the invention is to reduce the complexity and costs of producing the article.

[0049] The technical task and the objects specified are achieved by a nonwoven fabric production plant as claimed in the attached Claim 1 .

[0050] Preferred embodiments are highlighted in the dependent claims.

[0051] The features and advantages of the invention are clarified below by the detailed description of preferred embodiments of the invention, with reference to the attached drawings, in which:

[0052] Fig. 1 shows a cross-sectional view of a plant for producing nonwoven fabric according to the invention;

[0053] Fig. 2 illustrates an exploded view of the plant of Fig. 1 ;

[0054] Fig. 3a is a cross-sectional perspective view of a rectangular spinneret of a plant for producing nonwoven fabric according to the invention;

[0055] Fig. 3b represents a cross-sectional perspective view of a circular spinneret of a plant for producing nonwoven fabric according to the invention;

[0056] Fig. 4 shows a perspective view of a spinneret support of a plant for producing nonwoven fabric according to the invention;

[0057] Fig. 5a illustrates an upper schematic view, i.e. from the viewpoint of the dispenser, of the first holes and slits and second holes, shown in hatched lines, of a spinneret of a plant for producing nonwoven fabric according to the invention in which the slits are parallel to the main axis and continuous;

[0058] Fig. 5b is an upper schematic view, i.e. from the viewpoint of the dispenser, of the first holes and slits and second holes, shown in hatched lines, of a spinneret of a plant for producing nonwoven fabric according to the invention in which the slits are parallel to the main axis and offset between a first portion and a second portion of the spinneret along the main axis;

[0059] Fig. 5c represents an upper schematic view, i.e. from the viewpoint of the dispenser, of the first holes and slits and second holes, shown in hatched lines, of a spinneret of a plant for producing nonwoven fabric according to the invention in which the slits are slightly inclined with respect to the main axis;

[0060] Fig. 5d shows a lower schematic view, i.e. from the viewpoint of the collecting surface, of the first and second holes and slits, shown in hatched lines, of a spinneret of a plant for producing nonwoven fabric according to the invention in which the slits are perpendicular to the main axis;

[0061] Fig. 5e illustrates a lower schematic view, i.e. from the viewpoint of the collecting surface, of the first and second holes and slits, shown in hatched lines, of a spinneret of a plant for producing nonwoven fabric according to the invention in which the slits are sharply inclined with respect to the main axis;

[0062] Fig. 6 is a lower schematic view, i.e. from the viewpoint of the collecting surface, of the first and second holes and slits, shown in hatched lines, of a circular spinneret of a plant for producing nonwoven fabric according to the invention;

[0063] Fig. 7 represents a cross-sectional view of an apparatus for producing nonwoven fabric according to the invention in which are present, in sequence and parallel to the main plane, a plant for producing spunbond-type nonwoven fabric, a plant for producing meltblown nonwoven fabric, and a plant for producing spunbond-type nonwoven fabric without the external booth;

[0064] Fig. 8a shows a schematic view of an apparatus for producing nonwoven fabric according to the invention in which the conveying station includes a pair of smooth rollers;

[0065] Fig. 8b illustrates a schematic view of an apparatus for producing nonwoven fabric according to the invention in which the conveying station includes a first pair of smooth rollers and a second pair of rollers, downstream of the first pair, equipped with needles on the contact surface;

[0066] Fig. 8c is a schematic view of an apparatus for producing nonwoven fabric according to the invention in which the conveying station includes a pair of rollers equipped with needles on the contact surface positioned abutting the collecting surface;

[0067] Fig. 9a represents a cross-sectional view of an apparatus for producing nonwoven fabric according to the invention in which are present in a booth, in sequence and parallel to the main plane, a plant for producing spunbond-type nonwoven fabric, a plant for producing meltblown nonwoven fabric, and a plant for producing spunbond-type nonwoven fabric and the conveyor station includes two pairs of smooth rollers;

[0068] Fig. 9b shows a cross-sectional view of an apparatus for producing nonwoven fabric according to the invention in which are present in a booth, in sequence and parallel to the main plane, a cellulose or viscose dispensing plant, a plant for producing spunbond-type nonwoven fabric and a cellulose or viscose dispensing plant and the conveying station includes a pair of smooth rollers;

[0069] Fig. 9c illustrates a cross-sectional view of an apparatus for producing nonwoven fabric according to the invention in which are present in a booth, in sequence and parallel to the main plane, a cellulose or viscose dispensing plant, a plant for producing meltblown cusp-type nonwoven fabric, and a cellulose or viscose dispensing plant and the conveying station includes a pair of smooth rollers;

[0070] Fig. 9d is a cross-sectional view of an apparatus for producing nonwoven fabric according to the invention in which are present in a booth, in sequence and parallel to the main plane, a cellulose or viscose dispensing plant, a plant for producing spunbond-type nonwoven fabric and a cellulose or viscose dispensing plant and the conveying station includes a pair of rollers, one of which is smooth and one equipped with needles;

[0071] Fig. 9e represents a cross-sectional view of an apparatus for producing nonwoven fabric according to the invention in which are present in a booth, in sequence and parallel to the main plane, a cellulose or viscose dispensing plant, a plant for producing meltblown nonwoven fabric of the multirow coaxial meltblown type, and a cellulose or viscose dispensing plant, and the conveying station includes two pairs of smooth rollers;

[0072] Fig. 9f represents a cross-sectional view of an apparatus for producing nonwoven fabric according to the invention in which are present in a booth, in sequence and parallel to the main plane, a plant for producing nonwoven fabric of the multi-row coaxial meltblown type, a cellulose or viscose dispensing plant, and a plant for producing nonwoven fabric of the multi-row coaxial meltblown type in which the meltblown type plants define converging dispensing directions with respect to the dispensing plane and the conveying station comprises a pair of smooth rollers;

[0073] Fig. 10 shows a cross-sectional view of a dispenser and spinneret of a plant for producing nonwoven fabric according to the invention in an embodiment in which the spinneret includes a first body and a second body, the slits form a grid and are defined by the coupling between the bodies, and the cross-sectional view shows offset rows of protuberances as highlighted in the enlargements in the figure;

[0074] Fig. 11 illustrates an exploded view of the plant in Fig. 10;

[0075] Fig. 12 is a cross-sectional and exploded perspective view of the assembly of Figs. 10 and 11 ;

[0076] Fig. 13 represents a detail view of the protuberances separated by the grid of slits parallel to the first rows and transverse first rows that may be present alternatively on a face of the spinneret, or of the dispenser or of one of the bodies of a plant for producing nonwoven fabric according to the invention;

[0077] Fig. 14 shows a cross-sectional view of a plant for producing nonwoven fabric according to the invention in an embodiment in which the spinneret includes tubes and the slit is one only and it diffuses air around the tubes, the free end of which and from which polymeric fluid exits, is offset with respect to the air outlet end of the second holes;

[0078] Fig. 15 illustrates an exploded view of dispenser and spinneret of the plant of Fig. 14;

[0079] Fig. 16 is a longitudinal view of a tube of a plant for producing nonwoven fabric according to the invention in an embodiment in which the tube includes two inner narrowings and two outer narrowings;

[0080] Fig. 17a represents a front view of the spinneret outlet of a plant for producing nonwoven fabric according to the invention in which the spinneret includes tubes of circular shape and the second holes are distributed in fours around each first hole and thus each tube; Fig. 17b shows a front view of the spinneret outlet of a plant for producing nonwoven fabric according to the invention in which the spinneret includes tubes of circular shape and the second holes are distributed in sevens around each first hole and thus each tube;

[0081] Fig. 17c represents a front view of the spinneret outlet of a plant for producing nonwoven fabric according to the invention in which the spinneret includes star-shaped tubes with three arms and the second holes are distributed in sevens around each first hole and thus each tube; and

[0082] Fig. 18 shows a cross-sectional view of an apparatus for producing nonwoven fabric according to the invention in which is present, in a booth, a plant for producing nonwoven fabric according to the invention comprising tubes and in which the combined pathway of the cooling air inside the booth is shown.

[0083] In this document, when measurements, values, shapes, and geometric references (such as perpendicularity and parallelism) are associated with words like "approximately" or other similar terms, such as "almost" or "substantially", they are to be understood as excluding measurement errors or inaccuracies due to production and / or manufacturing errors and, above all, as having a less than slight deviation from the associated value, measurement, shape, or geometric reference. For example, if associated with a value, such terms preferably indicate a deviation by no more than 10% of the value in question.

[0084] Moreover, when used, terms such as "first", "second", "upper", "lower", "main" and "secondary" do not necessarily identify an order, a priority of relationship or relative position, but can simply be used to clearly distinguish between their different components.

[0085] Unless otherwise specified, as reflected in the following discussions, terms such as "processing", "computing", "determination", "calculating", or the like are considered as referring to the action and / or processes of a computer or similar electronic computing device that manipulates and / or transforms data represented as physical, such as electronic quantities of records of a computer system and / or memories, in other data similarly represented as physical quantities within computer systems, records, or other information storage, transmission, or display devices.

[0086] Unless otherwise stated, the measurements and data reported in this text shall be considered as provided in international standard atmosphere specified by the International Civil Aviation Organization (ICAO) (ISO 2533:1975).

[0087] With reference to the Figures, the plant for producing nonwoven fabric according to the invention is globally referred to as number 1.

[0088] Plant 1 for producing nonwoven fabric according to the invention is preferably of the spunbond type. Therefore, as in every spunbond plant, plant 1 is at least suitable for conveying polymeric filaments on a depositing surface to produce nonwoven fabric.

[0089] It should be remembered that, by nonwoven fabric is meant any type of fabric whose filaments are deposited in bulk, i.e. they are not sorted by means of a loom or other means with which they can be woven in a weave, with warp and weft, but are instead mingled in one or more layers of an article by deposition on a depositing surface, as further explained later. Therefore, nonwoven fabric can be produced not only, as is done conventionally, from a polyester filament, but from any natural or synthetic material such as, for example, polypropylene, nylon, cellulose, viscose, and, of course, polyester itself.

[0090] Similarly, filament means any filiform element defining, in general, a chemical, acrylic and synthetic fiber.

[0091] It is also specified that plant 1 is suitable for producing nonwoven fabric, but it is also capable of producing, more basically, only one or more filaments that can be used for nonwoven fabric production or used in some other way, such as unwound.

[0092] In any case, preferably, plant 1 extends mainly along a main axis 1a. The main axis 1 a is a virtual axis, for example barycentric, along which plant 1 extends.

[0093] In addition, plant 1 also extends along a main plane 1b. Main plane 1 b can be provided, for example, by an intermediate plane, preferably parallel to the support surface on which the polymeric filaments comprising the nonwoven fabric are deposited.

[0094] Main axis 1 a may be parallel, and in some cases co-planar, to the main plane 1 b.

[0095] In addition, plant 1 defines a vertical axis 1c.

[0096] The vertical axis 1 c is preferably perpendicular to the main axis 1 a. Hence, the vertical axis 1 c is preferably also perpendicular to the main plane 1 b. Therefore, vertical axis 1 c is preferably oriented perpendicular to the support surface on which the polymeric filaments that make up the nonwoven fabric are deposited and runs along plant 1 from upstream to downstream.

[0097] Thus, vertical axis 1 c is essentially an extrusion axis along which at least part of the polymeric fluid is conveyed to the dispensing stage in plant 1 .

[0098] Plant 1 includes, like all spunbond-type plants, at least an extrusion head 2, a dispenser 3 and a spinneret 4.

[0099] Specifically, plant 1 includes extrusion head 2, dispenser 3 and spinneret 4, preferably in this order, along vertical axis 1 c.

[0100] Thus the polymeric fluid is introduced into extrusion head 2, then into dispenser 3 and then distributed into spinneret 4.

[0101] Preferably, the polymeric fluid is chosen from among polypropylene, polyester, nylon, cellulose, polyester, and viscose.

[0102] Extrusion head 2 is preferably basically a common extrusion head, also known by the term coathanger.

[0103] Preferably, extrusion head 2 is suitable for directing a polymeric fluid to dispenser 3. Therefore, preferably, extrusion head 2 includes at least one main channel 20.

[0104] Main channel 20 is a narrow slot or pipe of any shape or size and can therefore be cylindrical or square compatible with the other elements that main channel 20 interfaces with.

[0105] Main channel 20 is preferably designed to allow the passage of polymeric fluid through extrusion head 2. In particular, main channel 20 is suitable for causing the polymeric fluid to flow to dispenser 3. Of course, extrusion head 2 could also include a plurality of main channels 20.

[0106] Dispenser 3, as mentioned above, receives polymeric fluid from extrusion head 2, specifically from main channels) 20, so as to distribute it.

[0107] Therefore, dispenser 3 is preferably integral with extrusion head 2.

[0108] Dispenser 3 is also referred to as a breaker plate. It therefore includes at least one dispensing duct 30.

[0109] Dispensing duct 30 is in fluid passage connection with main channel 20 and is designed to distribute the polymeric fluid. In detail, dispensing duct 30 distributes the polymeric fluid to spinneret 4 to produce the polymeric filaments that then go on to form the nonwoven fabric.

[0110] Both main channel 20 and dispensing duct 30 can define complex shapes. In addition, they can split and provide sub-channels for distribution of the polymeric fluid. In other words, dispenser 3 may also include a plurality of dispensing ducts 30 arranged downstream of main channel 20, each one being suitable for distributing smaller amounts of polymeric fluid than the main channel 20. Preferably, dispenser 3 includes a plurality of dispensing ducts 30 such that the polymeric fluid is distributed along main plane 1 b.

[0111] Dispenser 3 preferably includes at least one seat and filter media.

[0112] This seat is, preferably, adjacent to extrusion head 2 and placed between main channel 20 and dispensing duct 30.

[0113] More specifically, the seat can be made in dispenser 3 in the area interfacing with extrusion head 2. Thus, dispenser 3 may include a single seat or it may have a plurality of adjacent seats distributed along dispenser 3 transversally to vertical axis 1 c.

[0114] The filter media are preferably accommodated in the seat.

[0115] The seat is, therefore, basically a tank inside which filter media can be placed. The latter are preferably arranged between main channel 20 and the dispensing duct(s) 30, i.e. preferably in the seat, in such a way as to filter the polymeric fluid.

[0116] The filter media, in particular, preferably include a porous element.

[0117] The porous element defines a plurality of passage channels that are non-rectilinear and irregularly- sized.

[0118] Basically it is structurally similarly to a sponge. In this sense, it is not meant that the porous element is a soft element that can be easily deformed. On the contrary, the porous element is preferably defined in terms of stiffness and hardness by the materials and manufacturing processes distinguishing it.

[0119] However, the porous element also includes, like sponges, a plurality of pores that make the porous element itself substantially uneven and isotropic.

[0120] In particular, preferably, the porous element is an element made using the sintering technique.

[0121] Due to the implementation process, this technique preferably includes a plurality of non-rectilinear passage channels of varying sizes.

[0122] The term dimensions refers to all dimensions that contribute to determining the volume of the cavities or pores characterizing the porous element.

[0123] More in detail, preferably, filter media include a plurality of pores, or cavities, defining passage channels when adjacent. In other words, the consequentiality of the pores makes the passage channels for the polymeric fluid.

[0124] Also, preferably, each of the pores has a porosity greater than or equal to 18 pm.

[0125] As mentioned above, the porous element is preferably processed by sintering and, therefore, comprises a plurality of mutually sintered particles of the same material. The particles can therefore be of any material, as long as it is resistant to passage of the polymeric fluid. For example, the porous element comprises metallic material.

[0126] In addition, the sintered particles can be of different types.

[0127] For example, in a first embodiment, the particles can be components chosen from among spheres or fragments.

[0128] In a second embodiment, the porous element may include mutually intertwined and sintered filaments.

[0129] In a third embodiment, the porous element may include a first layer and a second layer. These layers are preferably mutually overlapping and include components and filaments, respectively, as previously described. In detail, preferably, the first layer and the second layer are adjacent to extrusion head 2 and dispenser 3, respectively; alternatively they are adjacent to dispenser 3 and extrusion head 2, respectively.

[0130] In addition, single-layer sintering of both particles and filaments can be provided.

[0131] The porous element can then be made in a piece with dispenser 3 or, preferably, it is removably available in dispenser 3, particularly in the seat.

[0132] Preferably, therefore, the porous element is counter-shaped to part of the seat and removably arranged in the seat.

[0133] Accordingly, in cases where there are multiple seats, dispenser 3 may include a plurality of porous elements that can be introduced like pads in the appropriate seats.

[0134] Advantageously each seat is adapted to accommodate the porous element in such a way that the latter is spaced from the dispensing duct 30. Preferably, especially when dispenser 3 includes a plurality of dispensing ducts 30, the seat is configured to avoid adhesion between the filter media and dispensing ducts 30.

[0135] Thus, in general, the seat is configured to distance the filter media and the dispensing duct 30, with at least a separation space being realized.

[0136] The separation space is preferably a portion of the free space between the porous element and the dispensing duct 30 defining a thickness along vertical axis 1 c.

[0137] Preferably, the thickness of the separation space is greater than or equal to 500 pm.

[0138] Even more preferably, the separation space is between 500 pm and 8 mm.

[0139] Preferably, but not necessarily, the separation space defines a thickness greater than or equal to the thickness of the porous element. The latter, in the preferred embodiment, defines a thickness of at least 1 .5 mm. In even greater detail, preferably, the porous element defines thicknesses of between 1 .5 mm and 8 mm.

[0140] To achieve separation between the filter media and the mouth of dispensing duct 30, the seat may include support means.

[0141] The support means are preferably suitable for enabling the porous element to rest upon them in such a way that the latter remains in the seat spaced from the dispensing duct(s) 30.

[0142] Therefore, the support means may include a support frame, such as or other spacer elements capable of achieving at least the separation space.

[0143] Spinneret 4 is preferably a separate element from dispenser 3, as in common spunbond plants. However, preferably, spinneret 4 is at least integral with dispenser 3.

[0144] Advantageously, spinneret 4 comprises a plurality of first holes 40. Each of the first holes 40 preferably extends transversally to the main plane 1 b.

[0145] In addition, each of the first holes 40 is preferably in fluid passage connection with the dispensing duct 30, or dispensing ducts, and suitable for extruding polymeric fluid to produce a respective filament, preferably polymeric.

[0146] Appropriately, first holes 40 may have diameters that vary in dimension depending on the use for which they are intended.

[0147] In addition, first holes 40 can be circular shaped, or define other shapes transversal to their own axis of development, that is, defined by cross-sections of first holes 40 of different shapes and sizes. For example, first holes 40 can define a circular, quadrangular, triangular shape, with sharp or preferably beveled corners and also present concavity or convexity.

[0148] Advantageously, spinneret 4 of plant 1 according to the invention includes at least one slit 41.

[0149] Slit 41 preferably runs parallel to main plane 1 b. Thus, slit 41 is suitable for allowing air to pass through spinneret 4.

[0150] Slit 41 can extend from one side of spinneret 4 to the other. Or, slit 41 may also extend only partially within spinneret 4.

[0151] Thus, spinneret 4 also advantageously includes a group of second holes 42.

[0152] Second holes 42 are also in fluid passage connection with slit 41 .

[0153] Second holes 42 thus extend parallel to first holes 40 in such a way as to allow air to flow out of slit 41.

[0154] Hence, first and second holes 40, 42 extend along or parallel to one or more of the dispensing directions 4a along which are dispensed the polymeric filament and the air that pushes the filaments out from plant 1 .

[0155] The one or more dispensing directions 4a, therefore, correspond to the directions along which the polymeric filaments are dispensed by spinneret 4.

[0156] Second holes 42 are preferably distributed all along spinneret 4 so that the air exiting spinneret 4, particularly from slit 41 , can interact with the polymeric fluid exiting from all of first holes 40.

[0157] In addition, slit 41 can be single and extend parallel to main plane 1 b such that it is in fluid passage connection with all of second holes 42.

[0158] Or, spinneret 4 may comprise a plurality of slits 41 , each in fluid passage connection with respective groups of second holes 42.

[0159] In fact, preferably, first holes 40 are organized into first rows 40a.

[0160] First rows 40a are basically mutually distinct, separate and parallel rows of first holes 40. Thus, slits 41 are, in turn, preferably mutually distinct and separate. In addition, slits 41 extend parallel to first rows 40a and between the reciprocally adjacent first rows 40a.

[0161] In even greater detail, slits 41 extend in such a way that they do not interfere with first holes 40. Furthermore, advantageously, spinneret 4 includes pluralities of groups of second holes 42 each in fluid passage connection with a respective slit 41.

[0162] Spinneret 4 could include first holes 40 additionally organized also in transverse first rows 40b. First transverse rows 40b are preferably transversal, e.g. perpendicular, to first rows 40a. So, in other words, slits 41 can form a grid parallel to first rows 40a and transverse first rows 40b.

[0163] Therefore, in turn, slits 41 may also extend parallel to transverse first rows 40b and between reciprocally adjacent second rows 40b.

[0164] In even more detail, slits 41 can extend in such a way that they do not interfere with first holes 40. Thus, advantageously, spinneret 4 may comprise pluralities of groups of second holes 42 each in fluid passage connection with a respective slit 41 , either parallel to first rows 40a or parallel to transverse first rows 40b.

[0165] Therefore, in this embodiment, first holes 40 can be separated from slits 41 by respective protuberances 43. Protuberance 43 is basically a barrier extending parallel to the one or more directions of dispensing 4a around, and thus defining part of, first hole 40 in such a way as to separate it from slits 41 .

[0166] Preferably each of said protuberances (43) extends at the points of incidence between first rows (40a) and transverse first rows (40b).

[0167] Thus, slits 41 can be operationally produced as grooves separating protuberances 43.

[0168] Spinneret 4 can be all of a piece, and each protuberance 43 can be obtained while making slits 41 as a remaining part of the perforated spinneret 4.

[0169] For example, slit 41 may extend parallel to main plane 1 b between opposite faces of spinneret 4 with respect to vertical axis 1 c. Or, slit(s) 41 may extend at a face of spinneret 4 suitable for coupling with dispenser 3.

[0170] In this sense, for example, the face of spinneret 4 may be configured so that protuberances 43 come into contact with the face of dispenser 3 to put first holes 40 in fluid passage connection with respective dispensing ducts, so that slit(s) 41 are / is in fact defined and made in the remaining space separating spinneret 4 and dispenser 3.

[0171] Or, in another embodiment, spinneret 4 might also not be in one piece and comprise a first body 400 and a second body 401 .

[0172] If present, first body 400 and second body 401 can be configured to be coupled. In particular, second body 401 is preferably placed between first body 400 and dispenser 3. Therefore, if present, first body 400 can correspond to the terminal of spinneret 4 and second body 401 to a plate interposed between dispenser 3 and first body 400, as shown for example in Figs. 10-12.

[0173] They are also configured to define, when coupled together, slits 41.

[0174] First 400 body may, for example, include at least part of first holes 40 and second holes 42.

[0175] Thus, second body 401 may include only part of first holes 40 surrounded by respective protuberances 43 such that when second body 401 is coupled to first body 400 and / or dispenser 3, protuberances 43 allow first holes 40 to be isolated from slits 41 while putting dispensing ducts 30 and first holes 40 in fluid passage connection. Thus, slits 41 are defined and bounded between adjacent faces of coupled bodies 400, 401 , or between adjacent faces of second body 401 and dispenser 3.

[0176] Naturally slits 41 can be made as grooves engraved on the face of spinneret 4 suitable for being coupled with dispenser 3, possibly particularly on the face of second body 401 , or on the corresponding face of dispenser 3 itself. Or slits 41 can be made as grooves engraved on the face of second body 401 suitable for coupling with first body 400, or even on the corresponding face of first body 400.

[0177] In general, therefore, protuberances 43 can be in one piece with one of the elements that make up one of spinneret 4, dispenser 3 or bodies 400, 401 .

[0178] Alternatively, spinneret 4 or dispenser 3, or one of the bodies 400, 401 , can include a seat. If present, the seat is in fluid passage connection either with only dispensing ducts 30, or with first holes 40, or even with both first holes 40 and second holes 42 depending on where the seat is located.

[0179] Thus, the seat, if any, is configured to accommodate protuberances 43 such that dispensing ducts 30 and first holes 40 are put in fluid passage connection and, most importantly, slits 41 are formed in the seat in fluid passage connection with second holes 42.

[0180] Thus, in general, spinneret 4 can be in one piece and include at least one slit 41 , the latter made inside spinneret 4 between two mutually opposite faces with respect to vertical axis 1 c, or placed on a face adjacent to dispenser 3 and defined when spinneret 4 is coupled with dispenser 3, or defined by dispenser 3 on the face of spinneret 4 when spinneret 4 is coupled with dispenser 3 (in the latter case, part of the plate comprising dispenser s actually comprises part of spinneret 4, since first holes 40 would be at least partly included in said plate comprising dispenser 3).

[0181] Or, if spinneret 4 is not made all of a piece, slit 41 can be made when bodies 400, 401 are mutually coupled according to the different configurations previously described and shown in Figs. 10-13, particularly at least between bodies 400, 401 .

[0182] In addition, spinneret 4 can define specific shapes and sizes consistent with the structure of plant 1 and, for example, of dispenser 3.

[0183] So, for example, spinneret 4 can define a rectangular shape, or more generally a quadrangular shape, or even a rounded shape, for instance circular.

[0184] Thus, spinneret 4 can determine specific orientations of first rows 40a, and transverse first rows 40b if present, and thus also of slits 41 , with respect to main axis 1 a.

[0185] For example, in a first embodiment shown in Figs. 5a-5b and 6, first rows 40a can extend parallel to main axis 1 a.

[0186] Or, as shown in Figs. 5c-5e, first rows 40a can extend transversally to main axis 1 a such that they are perpendicular (Fig. 5d) to main axis 1 a or obliquely (Figs. 5c and 5e) with respect to main axis 1 a.

[0187] In any embodiment, spinneret 4 can be divided into portions or regions. For example, spinneret 4 may include a first portion 4' and a second portion 4".

[0188] If present, first and second portions 4', 4" include respective first rows 40a reciprocally offset such that each first row 40a of first portion 4' is aligned with a respective slit 41 of second portion 4" and that, conversely, each first row 40a of second portion 4" is aligned with a respective slit 41 of first portion 4', as for example shown in Fig. 5b.

[0189] Second holes 42 can also be arranged in specific ways.

[0190] For example, advantageously, second holes 42 of one or more among the groups of second holes 42, preferably of each of the groups, are organized into at least one pair of second rows 42a. Second rows 42a are mutually distinct, separate and parallel. Thus, second rows 42a are preferably each placed near a respective first row 40a and / or transverse first row 40b respectively of two adjacent first rows 40a and / or two adjacent transverse first rows 40b.

[0191] Advantageously second holes 42 of each second row 42a are preferably arranged offset with respect to first holes 40 of an adjacent first row 40a or adjacent transverse first row 40b so as to be positioned, transversally to the first row 40a or the transverse first row 40b, between two adjacent first holes 40 of the first row 40a or the transverse first row 40b.

[0192] In this way, second holes 42 allow air coming out of spinneret 4 to be delivered, surrounding all of the filaments coming out of first holes 40.

[0193] Since slit 41 is suitable for allowing the passage of air, plant 1 preferably also includes conveying means 5.

[0194] Conveying means 5 are in fluid passage connection with slit 41. Thus, conveying means 5 are configured to convey air into slit 41 .

[0195] The air conveyed is, therefore, exchange air that thus allows cooling of first holes 40 and consequently the polymeric fluid, at least externally, before the polymeric fluid comes out of spinneret 4.

[0196] In addition, since air also comes out through second holes 42 adjacent to first holes 40, it also directly cools the polymeric fluid immediately as it exits spinneret 4 and also between first holes 40, as explained above.

[0197] This technical aspect is very advantageous as will be better explained later.

[0198] In addition to what has been described, plant 1 may include additional details.

[0199] As mentioned above, spinneret 4 is preferably separated from dispenser 3 and can define, for example, a quadrangular (Fig. 3a) or circular shape (Fig. 3b.

[0200] Plant 1 can, therefore, also comprise a support 6.

[0201] Support s, shown for example in Figs. 1-2 and 4, if present, is integral with dispenser s. Thus, support 6 is suitable for supporting spinneret 4 in such a way as to keep it integral with dispenser 3.

[0202] In this regard, preferably support 6 includes a seat 60.

[0203] Seat 60 is perforated and accommodates spinneret 4 without obstructing holes 40, 42. Therefore, in turn, conveying means 5 preferably include one or more conveying ducts 50.

[0204] The one or more conveying ducts 50 preferably extend between extrusion head 2, dispenser 3 and support 6. In addition, conveying ducts 50 are in fluid passage connection with one or more slits 41 , preferably either one with all slits 41 , or each with the same slit 41 or a reciprocal slit 41 .

[0205] In conclusion, plant 1 preferably includes extrusion head 2, dispenser 3 and support 6 reciprocally distinct, separate and, in this order, reciprocally constrained. Thus, spinneret 4 is removably constrained to support 6 trapped in seat 60 between dispenser 3 and support 6.

[0206] Plant 1 can also be configured differently. For example, plant 1 may still be of the spunbond type, but have a hybrid conformation including elements typical of multi-row coaxial meltblown plants.

[0207] In general, each first hole 40 and the at least one dispensing duct 30 can be placed in fluid passage connection by a respective tube 34.

[0208] In a particular embodiment, dispenser 3 may preferably comprise a plurality of dispensing ducts 30 each in fluid passage connection with a respective first hole 40 of spinneret 4.

[0209] Thus each first hole 40 and the at least one dispensing duct 30, or each first hole 40 and respective dispensing duct 30, can be placed in fluid passage connection via a respective tube 34.

[0210] In other words, spinneret 4 may comprise a plurality of tubes 34, each of which housed in a respective first hole 40 in fluid passage connection with the respective dispensing duct 30 as would be the case in a coaxial meltblown type plant.

[0211] Tube 34 is, as such, a substantially elongated element comprising a cavity through which liquid polymer can percolate to allow extrusion, e.g. from a spinneret.

[0212] In addition, tube 34 defines a variety of shapes, preferably reciprocally identical or similar, in planes transversal to dispensing direction 4a.

[0213] Such shapes may be circular, as in common tubes, or differently shaped. For example, the shapes can be triangular, quadrangular, star-shaped or other possible shapes inscribed inside a circle.

[0214] Thus slit 41 is preferably a single slit that runs parallel to main plane 1 b in such a way that it extends over all of first holes 40 and, therefore, tubes 34. In this case, therefore, slit 41 can preferably break first holes 40 into two parts reciprocally separated from slit 41 itself and reciprocally interconnected, isolated from slit 41 by respective tube 34.

[0215] In addition, in greater detail, slit 41 also runs transversally to tubes 34 themselves so that the air can circulate around tubes 34 toward second holes 42.

[0216] Second holes 42 can then be distributed around each of first holes 40, in this case also around respective tubes 34, in fluid passage connection with slit 41 . Preferably, in this case, slit 41 is a single slit, but spinneret 4 could also in this case comprise a plurality of slits 41 in fluid passage connection with respective groups of second holes 42.

[0217] In this specific case, tubes 34 can deliver polymeric fluid from the same delivery plane as second holes 42, i.e. with the ends of tubes 34 aligned with the ends of second holes 42 exiting spinneret 4 transversally to the dispensing direction 4a, or they can define an additional feature.

[0218] Specifically, tubes 34 and second holes 42 preferably deliver the polymeric fluid and air, respectively, from reciprocally offset ends parallel to or along the dispensing direction 4a. Specifically and preferably, tubes 34 each define a free end from which the polymeric fluid is dispensed that is spaced, parallel to or along the delivery direction 4a, from the air delivery end of second holes 42.

[0219] The ends can be offset in either direction parallel to the dispensing direction 4a.

[0220] In this sense, therefore, the polymeric fluid can be delivered more internally or more externally to spinneret 4 than the air, that is, closer to or farther away from dispenser 3.

[0221] In other words, second holes 42 preferably all deliver air at ends lying on a first dispensing plane transversal to dispensing direction 4a, while tubes 34 all deliver polymeric fluid at ends lying on a second dispensing plane transversal to dispensing direction 4a and spaced from the first dispensing plane.

[0222] The dispensing planes can therefore be offset from each other by a distance of between 0 mm (and in this case they are coincident and the ends are aligned) and ±1 cm.

[0223] Preferably, the ends of tubes 34 and second holes 42 are configured so that the polymeric fluid is delivered more externally to the spinneret 4 than the air, i.e. further away from dispenser 3. In any case, it is advantageous, although not necessary, that the outflow of polymeric fluid and air from spinneret 4 does not occur in the same plane transversal to dispensing direction 4a in order to limit outflow interference.

[0224] Tubes 34 can also define additional features.

[0225] For example, tubes 34 may define one or more narrowings 43. Narrowings 43, if present, essentially correspond to dimensional reductions of tube 34 in a plane transversal to dispensing direction 4a. Specifically, tubes 34 can be defined as internal narrowings 43a and / or internal narrowings 43b.

[0226] Internal narrowings 43a are defined, internally to tube 34, by inner walls i.e. the walls in contact with the polymeric fluid. On the other hand, external narrowings 43b are defined, externally to tube 34, by outer walls i.e. the walls in contact with the air or the rest of spinneret 4.

[0227] Preferably, tubes 34 define two or more internal narrowings 43a.

[0228] Internal narrowings 43a are, in detail, distributed parallel to the dispensing direction 4a in such a way that tube 34 is internally convergent from the inside of spinneret 4 to the outside, i.e. larger at the mouth of the respective dispensing duct 30 and smaller at the free end.

[0229] In addition, especially if tubes 34 define ends that are offset with respect to second holes 42, they also preferably include two or more external narrowings 43b.

[0230] The external narrowings 43b are, in detail, also distributed parallel to the dispensing direction 4a in such a way that tube 34 is externally convergent from the inside of spinneret 4 to the outside, i.e. larger at the mouth of the respective dispensing duct 30 and smaller at the free end, in this case so as to reduce the interference between the polymeric fluid outlet and the air.

[0231] Plant 1 , therefore, is capable of delivering filaments, preferably polymeric, along and parallel to the dispensing direction 4a, which can be parallel to vertical axis 1 c or even inclined with respect to it. Preferably, plant 1 is used to produce nonwoven fabric. Preferably then, the filaments are deposited on a depositing surface, that is for instance movable, so that at least one layer of interlacing filaments is formed during the deposit.

[0232] However, plant 1 could be equivalently employed to produce a coil of filament or filaments. In this regard, in fact, it could be envisaged to place a coil tangent to one or more of the dispensing directions 4a, for example, extending parallel to main axis 1 a and rotating about an axis parallel to it, so that the filament is collected on the rotating coil.

[0233] In this way, the filament could also be used for weaving true and proper, employing weaving looms that can unwind the filament and weave it into warp and / or weft.

[0234] Similarly, the invention does not only comprise a new plant 1 .

[0235] In fact, the invention also makes it possible to make new apparatus.

[0236] Specifically, the invention enables at least one new apparatus for producing nonwoven fabric to be made, which, with reference to the Figures, is globally indicated as 100.

[0237] It is important to explain from the outset that apparatus 100 may include a plant 1 , or it may not.

[0238] In addition, plant 100 can be configured in different ways and, in greater detail, in at least two particular configurations.

[0239] In general, apparatus 100 includes, as do most apparatuses in which use of spunbond or meltblown plants is provided, a dispensing unit. In addition, the dispensing unit can include a booth 10. Thus, plant 100 comprises preferably a booth 10. However, especially but not only in some embodiments, plant 100, and particularly the dispensing unit, might not include a booth 10.

[0240] If present, booth 10 is basically a containing enclosure inside which a plant suitable for delivering filaments is normally housed, such as a plant 1. In general, the dispensing unit includes all the components of plant 1 , such as extrusion head 2, dispenser 3, spinneret 4, possibly also support 6, and conveying means 5. In the example where plant 1 is in booth 10, the latter includes all the components of plant 1 , such as extrusion head 2, dispenser 3, spinneret 4, possibly also support 6, and conveying means 5. Or, the dispensing unit, and thus the booth 10 itself, may also include, in this example, only spinneret 4, possibly support 6, in order to accommodate the filament in an enclosed environment.

[0241] In a particularly advantageous embodiment of apparatus 100, shown for example in Fig. 18, the latter includes at least one plant 1 including at least one dispenser 3 and one spinneret 4 including tubes 34.

[0242] In this case, including a plant 1 within a booth 10 allows for improved polymeric fluid outflow and more efficient management of both polymeric fluid stretching during filament formation and filament cooling.

[0243] Booth 10, if present, thus defines a closed containment volume, i.e. inaccessible from the outside.

[0244] In addition, in more detail, the dispensing unit, possibly if the same booth 10 is present, preferably includes at least one outlet 10a.

[0245] Outlet 10a is preferably the portion of the dispensing unit, possibly of booth 10, from which the filament(s) dispensed by the plant present in the dispensing unit, e.g. in booth 10, can exit.

[0246] Since spunbond or meltblown plants, as well as other plants suitable for dispensing filaments, are normally three-dimensional objects that extend along a plane transversal to the dispensing direction 4a, analogous to the main plane 1 b of plant 1 , outlet 10a, therefore, essentially extends along a dispensing plane 100a. Dispensing plane 100a is a virtual plane along which, or parallel to which, filaments are dispensed.

[0247] Therefore, outlet 10a defines a dispensing slit whose area extends transversally to the dispensing plane 100a.

[0248] Outlet 10a defines, in fact, a volume narrowing configured to allow dispensing from the dispensing unit, possibly from booth 10, of a plurality of filaments. The narrowing, as such, allows filaments in particular to be dispensed by Venturi effect by forming, at the outlet, a set of filaments that also results in the formation of a layer of filaments along or parallel to the dispensing plane 100a.

[0249] In addition, the dispensing unit, possibly if the same booth 10 is present, may also include a funnel- shaped portion 10b.

[0250] Funnel-shaped portion 10b is preferably placed, where present, upstream of outlet 10a. Funnel- shaped portion 10b thus converges toward outlet 10a so as to direct the filaments toward outlet 10a. This means that, for example, when filaments are deposited in the dispensing unit, in particular, for example, on the walls of booth 10, at the funnel-shaped portion 10b, they independently slide toward outlet 10a. Of course, as is the case in common booths, booth 10 may include cooling means that convey air from the sides of the plant toward the polymeric fluid exiting spinneret 4, as shown in Fig. 18. Thus, if a plant 1 , especially but not only equipped with tubes 34, is combined with the cooling means already present in booth 10, the overall efficiency of apparatus 100 can be optimized.

[0251] Apparatus 100 additionally includes a collecting surface 11.

[0252] The collecting surface 11 essentially corresponds to the surface previously referred to as the deposition or depositing surface. Collecting surface 11 thus runs transversally to the dispensing plane 100a downstream of the dispensing unit, i.e. of the outlet 10a, of the booth 10 where present. Collecting surface 11 is therefore configured to collect the layer exiting from outlet 10a in order to produce a nonwoven fabric article.

[0253] As mentioned above, apparatus 100 can include a plant 1 which, as described, is of the spunbond type.

[0254] More generally, apparatus 100 can include any plant to produce nonwoven fabric. In apparatus 100, the latter is housed in the dispensing unit, for example, in booth 10.

[0255] Thus, the plant extends along a main axis 1 a and a main plane 1 b that are transversal to dispensing plane 100a. In addition, the plant is configured to dispense toward outlet 10a at least one filament of the type chosen from among polymeric or cellulose or viscose along one or more dispensing directions 4a transversal to the main plane 1 b.

[0256] In a first inventive embodiment of apparatus 100, the latter advantageously includes additional plants in the dispensing unit, e.g. in booth 10.

[0257] In fact, the dispensing unit, particularly, for example, booth 10 preferably includes at least two plants distributed parallel to main plane 1 b, side-by-side. Of the two plants, preferably only one is of the spunbond or meltblown type.

[0258] Therefore, given the configuration, at least two distinct types of filaments dispensed by the plants are mixed simultaneously in the dispensing unit, for example, in booth 10 at outlet 10a.

[0259] In this way, filaments of different types make one and the same layer at the outlet of booth 10.

[0260] This is very important because, normally, in common apparatuses, the different filaments are not mixed before exiting from the dispensing unit, for example, from booth 10, but are instead layered on the collecting surface 11 by means of several booths equipped with a single plant arranged in succession.

[0261] In a particularly advantageous embodiment, the dispensing unit, possibly booth 10, preferably includes at least three plants distributed parallel to main plane 1 b in such a way that at least three filaments, at least two of which are of different types, are mixed simultaneously in the dispensing unit, for example in booth 10.

[0262] The plants in the dispensing unit, for example in booth 10, can, therefore, be configured in different ways.

[0263] First, the one or more dispensing directions 4a of each plant are either parallel to dispensing plane 100a or may converge toward dispensing plane 100a. This means that, for example, in an apparatus 100 in which there are three plants, they may include a central plant with dispensing direction 4a parallel to or aligned with dispensing plane 100a and lateral plants whose dispensing directions 4a converge toward dispensing plane 100a and are therefore incident with respect to dispensing direction 4a of the central plant and inclined with respect to.

[0264] Since plants can naturally deliver a plurality of filaments, and the delivery can be linear or conical, each plant can define, as for example shown in Figs. 9a-9f, dispensing cones within which the dispensing directions 4a are confined.

[0265] In addition, plants can define configurations of specific types.

[0266] For example, in an embodiment shown in Figs. 7 and 9a, booth 10 comprises, in this order, a spunbond type plant, a meltblown type plant, and a spunbond type plant. This configuration allows SMS-type layers to be obtained by simultaneous mixing of filaments, and is particularly advantageous for making diapers.

[0267] Or, in an embodiment shown in Figs. 9b-9e, booth 10 may include, in this order, a cellulose or viscose dispensing plant, a spunbond or meltblown type plant, and a cellulose or viscose dispensing plant.

[0268] Cellulose or viscose dispensing plants, similarly to the common meltblown and spunbond plants, are of themselves already known and are therefore not described in detail here.

[0269] This configuration allows absorbent layers to be obtained by simultaneous mixing of filaments, and is particularly advantageous for making wet wipes or similar.

[0270] Or again, in an embodiment shown in Fig. 9f, booth 10 may include, in this order, a meltblown or spunbond type plant, a cellulose or viscose dispensing plant, and a meltblown or spunbond type plant.

[0271] In cases where there are one or more meltblown plants in the dispensing unit, such as in booth 10, one of them can be of the type chosen between cusp (Fig. 9a) and multi-row coaxial (Figs. 9e-9f.

[0272] In addition, in cases where there are one or more spunbond type plants in the dispensing unit, for example in booth 10, they are preferably, but not necessarily, configured like plant 1 according to the invention.

[0273] Especially, but not solely, when apparatus 100 does not include meltblown plants, and includes combinations of spunbond type plants among themselves or with a cellulose or viscose dispensing plant, the dispensing unit may, as anticipated, not include booth 10. Therefore, in these embodiments not shown in the figures, the dispensing unit can be open, not defining a closed containment volume, and essentially include at least outlet 10a, preferably also funnel-shaped portion 10b.

[0274] The configurations of apparatus 100 according to the invention just described enable a new process for producing a nonwoven article to be obtained.

[0275] The process is, of course, implemented by apparatus 100.

[0276] Thus, the process advantageously includes at least one mixing stage.

[0277] In the mixing stage, preferably, at least two separate types of filaments dispensed by the plants at the mouth of outlet 10a in the dispensing unit, such as in booth 10, are mixed simultaneously.

[0278] As already said, filaments can also be mixed simultaneously in numbers of three.

[0279] The process then includes a dispensing stage. In the dispensing stage, a single layer made by the mixed filaments of different types is dispensed by the dispensing unit, such as from booth 10 through outlet 10a.

[0280] The process then includes a deposition phase. In the deposition stage, the layer is collected on a collecting surface 11 or on a reel. The layer thus deposited in this way enables a nonwoven fabric article with greatly improved mechanical properties to be produced.

[0281] Of course, the invention also includes the article made by a process as just described.

[0282] Apparatus 100 according to the invention can also be configured differently.

[0283] For example, apparatus 100 may comprise the dispensing unit as described, the collecting surface 11 and also only one plant configured to dispense toward outlet 10a at least one filament of the type chosen from among polymeric or cellulose or viscose along one or more dispensing directions 4a transversal to main plane 1 b.

[0284] All these features have already been described, in detail, above.

[0285] However, in a further inventive embodiment, apparatus 100 can also include a conveyor station 12. Conveyor station 12 is preferably placed between dispensing unit and collecting surface 11. In particular, in a preferred embodiment, conveyor station 12 is also positioned abutting outlet 10a so as to, advantageously, close outlet 10a.

[0286] Or, in an alternative embodiment, or even in combination with the previous embodiment, conveyor station 12 is positioned abutting collecting surface 11 .

[0287] Thus conveyor station 12 includes at least one roller 12a.

[0288] Roller 12 preferably extends parallel to the main plane 1 b. Thus, roller 12 preferably rotates about an axis of rotation oriented, for instance, parallel or perpendicular or obliquely to main axis 1 a. Therefore, advantageously, roller 12a is configured to convey the filaments of the filament layer in an orderly manner onto the collecting surface 11 , particularly by orienting the filaments perpendicularly or parallel to collecting surface 11 .

[0289] Roller 12 can of course be fixed or selectively orientable with respect to main axis 1 a.

[0290] Roller 12a, in even more detail, includes a contact surface 120.

[0291] Contact surface 120 is the portion of roller 12a suitable for contacting the filament(s) exiting the dispensing unit, from booth 10 where present.

[0292] Contact surface 120 can, therefore, be smooth.

[0293] Or, contact surface 120 may include one or more knurls. If present, the knurls are configured to pick up filaments from outlet 10a along dispensing plane 100a when the filaments enter into contact with contact surface 120. In addition, if present, the knurls are also configured to release the filaments in an orderly manner when the layer releases itself from contact surface 120.

[0294] In a particularly advantageous embodiment of apparatus 100, contact surface 120 preferably includes a plurality of needles 121.

[0295] Needles 121 are, if present, distributed radially along and around the axis of rotation. In addition, needles 121 protrude from contact surface 120.

[0296] Therefore, given the conformation, needles 121 are configured to punch the nonwoven layer delivered at outlet 10a so as to form punch marks distributed on the layer. Advantageously, at the punch marks, the filaments are then interlaced and bonded to each other.

[0297] Conveyor station 12 of apparatus 100 can also be configured in different ways.

[0298] For example, in a first embodiment shown in Figs. 8a-8b and 9a-9f, conveyor station 12 preferably includes at least one pair of mutually counter-rotating rollers 12a. In addition, rollers 12a are configured so that the layer transits between rollers 12 before being deposited on collecting surface 11.

[0299] In a further embodiment, as shown in Figs. 8b, 9a and 9e, conveyor station 12 can include two pairs of rollers 12a.

[0300] In addition, the rollers 12a of a pair of rollers may include an identical contact surface 120. Or, as in the embodiment of Fig. 9d, the rollers 12a of a pair of rollers may include a different contact surface 120, particularly for example, one smooth and one including needles, or also one smooth and one knurled or one knurled and one including needles.

[0301] In the embodiment with a single roller 12a, especially if the latter is as shown in Fig. 8c positioned abutting the collecting surface 11 , roller 12a preferably includes a contact surface 120 equipped with needles 121 .

[0302] Apparatus 100 as just described, in conclusion, can also include a calender 13.

[0303] If present, calender 13 is arranged downstream of conveyor station 12.

[0304] Calender 13 thus interacts with the nonwoven layer on the collecting surface 11 to produce a nonwoven fabric article.

[0305] The configurations of apparatus 100 according to the invention just described also enable a new process for producing a nonwoven fabric article to be obtained.

[0306] The process is, of course, still implemented by apparatus 100.

[0307] Thus, the process advantageously includes at least one dispensing stage.

[0308] In the dispensing stage, preferably, a layer of filaments of the type chosen from among polymeric or cellulose or viscose is dispensed from outlet 10a along dispensing plane 100a.

[0309] The process then also advantageously includes a conveying stage.

[0310] In the conveying stage, through the conveying station 12, the filaments of the layer are conveyed in an orderly manner onto collecting surface 11 by orienting the filaments perpendicularly or parallel to collecting surface 11 .

[0311] In greater detail, in the conveying stage, the layer is advantageously also punched so as to form punch marks distributed on the layer where the filaments are interlaced and bonded to each other. The process then also includes a deposition stage. In the deposition stage, the layer is preferably deposited on collecting surface 11 in such a way that an article is obtained.

[0312] If a calender 13 is also present, the process also includes a calendering stage in which the layer is calendered downstream of conveyor station 12 to obtain the article.

[0313] Of course, again in this case, the invention also includes a nonwoven article produced by a process as just described.

[0314] Plant 1 for producing nonwoven fabric, apparatus 100 for producing nonwoven fabric, processes for producing a nonwoven fabric article, and nonwoven fabric articles according to the invention provide important advantages.

[0315] In fact, spunbond plants of the known art cannot normally include spinnerets that are too wide due to the fact that the air, conveyed to the filaments only at the outlet of the spinneret and laterally, cannot reach the center of the fiber with the result that the uncooled fibers stick together or do not crystallize, with spinneret dripping creating serious damage to product quality. In contrast, plant 1 also allows filaments to be cooled internally within spinneret 4, resulting in more effective and efficient fiber cooling and, most importantly, in a more uniform manner.

[0316] Therefore, plant 1 allows for an increase in the number of fibers that are extruded from spinneret 4, thus appreciably increasing the kilograms of filaments produced, compared with the current technology.

[0317] Also, considering that in spunbond plants of the known art, the cooling air reaches the filaments from the sides and should, theoretically, be able to reach the center of the spinneret, the drilling layout of the polymeric fluid outlet must always necessarily have holes offset with respect to each other and spaced far enough apart for the air to be able to reach the center.

[0318] In contrast, plant 1 allows filaments to be cooled from above, thus allowing multiple extrusion holes in the same plant 1 , and possibly even multiple spinnerets 4, side-by-side and with different extrusion technology, such as for example spunbond and meltblown spinnerets side-by-side and working together forming a single layer at the same time.

[0319] Regarding apparatus 100, normally with the technology of the known art, to produce a nonwoven fabric to be used in the production of diapers, five layers of nonwoven fabric are needed, laminated together and then calendered, all five together, with the need to have five different apparatuses in the machine equipped with at least three plants with spunbond type spinnerets and plants with meltblown type spinnerets, which, as can be imagined, increases the cost of the product, with more layers of nonwoven fabric being laminated and calendered together anyway, leading to a lower quality, in mechanical terms, of the final product.

[0320] Instead, with the apparatuses 100 according to the invention, it is possible to arrange two or three plants side-by-side with each other, all in one piece or having separate components, which allow simultaneous work with several spinnerets of different types and thus to have, with plants within the same dispensing unit, possibly the same booth 10, the potential of three apparatus heads of the known art, significantly reducing the costs of investment, maintenance and consumption of electricity and air;

[0321] In addition, the simultaneous mixing, before the exit from the dispensing unit, possibly from booth 10, of filaments of different types, e.g. of the SMS type, greatly increases the quality of the article and significantly changes both its technical-mechanical and aesthetic characteristics.

[0322] Besides, if there are cellulose or viscose dispensing plants, equipped with respective conveyors or eductors from which cellulose and / or viscose or other material comes out, and dispensing plants for the polymeric filaments which, at the time they come out, encounter cellulose and / or viscose, mixing them together, apparatus 100 makes it possible to make a single layer of cloth comprised partly of polymer fiber and partly of cellulose and or viscose, cotton or other material.

[0323] In conclusion, while the known apparatuses allow the manufacture of articles endowed with good mechanical strength only in one direction, apparatuses 100 allow, conveying station 12 allows the filaments to be oriented so that they are deposited on collecting surface 11 not only in one direction but also possibly in a different direction, for example, at an oblique angle to the direction of advancement of collecting surface 11 . This different positioning of the filaments before passing under the calender allows the layer that has been formed to increase its mechanical strength in both directions.

[0324] In addition, having a conveyor station 12 in which at least one roller 12a includes needles 121 makes it possible to orient the filaments and, at the same time, perforate the layer formed by them in such a way as to partially bind them together before passing under the calender. This allows for additional mechanical strength on both sides of the article thus made.

[0325] The invention can be modified to create different versions falling within the scope of the inventive concept defined by the claims.

[0326] In particular, given the versatile conformation of spinneret 4, plant 1 can be used to make two- component nonwoven fabric. As known, two-component nonwovens are articles within which two distinct polymeric fluids are mixed.

[0327] Thus, in this case, slit 41 may preferably be suitable for allowing a second polymeric fluid to pass through spinneret 4, similar to that provided for the air.

[0328] In addition, of course, second holes 42 are in this case preferably designed to allow the second polymeric fluid to exit from slit 41 .

[0329] The conveying means 5 are then configured to convey the second polymeric fluid into slit 41 such that the second polymeric fluid flows out of spinneret 4 simultaneously with the first polymeric fluid.

[0330] In this context, all the details can be replaced by equivalent elements and any materials, shapes and dimensions can be used.

Claims

CLAI MS1. Apparatus (100) for producing nonwoven fabric including:- a dispensing unit including an outlet (10a) extending along a dispensing plane (100a) and configured to allow the dispensing from said dispensing unit of a plurality of filaments by Venturi effect forming a layer of said filaments along or parallel to said dispensing plane (100a),- a collecting surface (11) extending transversally to said dispensing plane (100a) downstream of said dispensing unit to collect said layer exiting said outlet (10a) so as to make a nonwoven fabric item;- at least one plant for producing nonwoven fabric housed in said dispensing unit, extending along a main axis (1 a) and a main plane (1 b) transversal to said dispensing plane (100a) and configured to dispense toward said outlet (10a) at least one filament of the type chosen from among polymeric or cellulose or viscose along one or more dispensing directions (4a) transversal to said main plane (1 b); and characterized in that- said dispensing unit includes at least two of said plants distributed parallel to said main plane (1 b) side-by-side of which only one is of the type of spunbond and meltblown so that at least two distinct types of said filaments dispensed from said plants are simultaneously mixed in said dispensing unit at the mouth of said outlet (10a) so that said filaments of different types make only one said layer at the outlet of said dispensing unit2. Apparatus (100) according to claim 1 , wherein said dispensing unit comprises at least three of said plants distributed parallel to said main plane (1 b) such that at least three of said filaments are simultaneously mixed in said dispensing unit.

3. Apparatus (100) according to the preceding claim, wherein said one or more dispensing directions (4a) of each said plant are parallel to said dispensing plane (100a) or converging toward said dispensing plane (100a).

4. Apparatus (100) according to any of claims 2-3, wherein said dispensing unit comprises, in this order, a spunbond type plant, a meltblown type plant, and a spunbond type plant.

5. Apparatus (100) according to any of claims 2-3, wherein said dispensing unit comprises, in this order, a cellulose or viscose dispensing plant, a spunbond or meltblown type plant, and a cellulose or viscose dispensing plant.

6. Apparatus (100) according to any of claims 2-3, wherein said dispensing unit comprises, in this order, a meltblown or spunbond type plant, a cellulose or viscose dispensing plant, and a meltblown or spunbond type plant.

7. Apparatus (100) according to any preceding claim, wherein at least one of said meltblown plants is also of the type chosen between cuspid or multi-row coaxial.

8. Apparatus (100) according to any preceding claim, wherein said dispensing unit comprises a booth (10) defining an enclosed containment volume including said outlet (10a) and a funnel- shaped portion (10b) located upstream of said outlet (10a) and converging toward said outlet (10a) to direct said filaments toward said outlet (10a).

9. Process of making a nonwoven fabric article implemented with an apparatus (100) according to any of the preceding claims, characterized in that:- at least two distinct types of said filaments dispensed by said plants at the mouth of said outlet (10a) in said dispensing unit are simultaneously mixed;- dispensing from said dispensing unit through said outlet (10a) a single layer made from said filaments of different types mixed together; - depositing said layer on said collecting surface (11) or on a reel so as to obtain an item.

10. Process according to the previous claim, wherein three of said filaments are mixed simultaneously in said mixing step.

11. Nonwoven fabric item produced by a process according to claims 9-10.

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