PLANT FOR THE PRODUCTION OF NON-WOVEN FABRIC

Abstract

 A plant for the production of non-woven fabric, comprising a support structure 2 provided with a main channel 3 extending along a vertical axis Y, a cooling station 8, which is placed along said main channel 3 and comprises a containment body 11 delimiting at least one cooling chamber 12 within said main channel 3 and defining internally at least an expansion chamber 7, cooling means in fluid connection with said expansion chamber suitable for introducing into said cooling chamber 12 at least a first air flow 10 for cooling filaments 7 capable of passing through said cooling chamber 12, homogenising means 13 housed within said expansion chamber and configured to intercept said first air flow 10 and generate a second air flow 14 substantially homogeneous at least parallel to said vertical axis Y, said containment body 11 comprises at least one door 51 movable between a closing position and an opening position, wherein a lateral opening 50 is free, and allows the removal and/or insertion of said homogenising means 13 from/into said expansion chamber 7 for their maintenance and/or cleaning.

Description

TECHNICAL FIELD

[0001] The present invention relates to a plant for the production of nonwoven fabric, in particular of plastic material, according to the preamble of independent claim number 1. The plant for the production of non-woven fabric in question is intended to be advantageously used in the field of the production of fibre tapes to form a non-woven fabric, normally tape-form. Such tapes are normally used for the production of health care products, such as headgear, masks and gloves, or in the agricultural industry for the production of non-woven fabric to be laid on the soil to be cultivated, to prevent weed growth and/or to protect seeds.

[0002] More specifically, the plant for the production of non-woven fabric subject matter of the present invention is advantageously employable to produce a continuous tape of semi-finished non-woven fabric intended to undergo subsequent processing to obtain a finished product.

[0003] The invention is therefore within the context of the industrial sector of production of non-woven fibre tape material, i.e. more generally, within the sector of non-woven fabric production.

BACKGROUND ART

[0004] In the technical field of reference, the production of tapes of mechanically connected fibres, normally made of plastic material, for the production of non-woven fabrics, such as spunbonds of polypropylene, polyester and/or other polymers, has been known, in particular for the production of bandages, gauzes, gauze, masks and other sanitary products, or for example for the production of non-woven fabrics intended for use in the agricultural industry to cover land for cultivation.

[0005] More generally, non-woven fabric is a semi-finished product intended to undergo further processing steps for the production of various products, normally made of plastic material and in the form of tapes or overlapping tapes. Such tapes are made up of filaments arranged randomly in layers and joined usually mechanically, or by adhesives, or at least partially fused together by heat.

[0006] More clearly, non-woven fabric (TNT) is the term well known in the technical sector to indicate an industrial product similar to a fabric but obtained by processes other than weaving and/or knitting. More specifically, in a non-woven fabric, the filaments composing it are mechanically bound together in a random pattern, without defining any ordered structure, unlike the filaments and/or fibres composing a fabric. In the technical sector, non-woven are known to be produced, for example, in which the filaments and/or fibres are arranged in layers or criss-crossed and mechanically joined together, for example by needling or using adhesives or similar. Sometimes, nonwoven fabric is also referred to in the English language by the term "nonwoven", which is also well known to the skilled person in the art.

[0007] In the aforementioned technical field of nonwoven production, nonwoven plants have been known, which normally involve the formation of a plurality of plastic filaments, which are stretched, laid on a conveyor belt and then pressed one on top of the other in a random manner to form the aforementioned nonwoven tapes.

[0008] An example of a nonwoven plant is described in the document EP 3831989. The plant described there extends vertically along a main channel, along which several operating units for the production of the aforementioned filaments of plastic material are foreseen vertically in sequence.

[0009] Above, there is provided an extrusion station for extruding a plurality of filaments of high temperature plastic material, which are fed into the main channel through an upper inlet port, at which an extrusion head is placed, from which the filaments exit below. As is well known, such an extrusion head is equipped inferiorly with a plurality of holes facing the upper inlet opening from which a mass of molten plastic material in the form of filaments exits.

[0010] The filaments are normally extruded in the form of a pasty plastic material at a high temperature, normally between 150°C and 280°C.

[0011] Underneath is a cooling station (normally known as 'quenching' or 'quench' in the technical industry jargon), in which an air flow is forced into the main channel by means of at least a fan placed outside the main channel.

[0012] The air flow fed into the cooling station cools the filaments formed at the exit of the extrusion head of the extrusion station.

[0013] The cooling station comprises side walls, normally metal, which define a cooling volume within which the high-temperature filaments begin to cool.

[0014] In order to extend the filaments obtained from the extrusion station and subsequently cooled by the cooling station, the known type of plant normally comprises an extension(or stretching) station, in which the air injected into the first inlet section extends the plastic filaments within a reduced section of the main channel until they reach the desired size, i.e. until they reach a linear density of approximately 1 - 5 dtex.

[0015] In order to obtain the desired non-woven fabric weave (i.e. a planar homogeneous arrangement of the filaments) for the production of the non-woven fabric, it is necessary to randomly weave the filaments together, forming a dense weave that is essentially seamless.

[0016] For this purpose, the plant of the known type is equipped with a deposition station at an end section of the main channel, which terminates at the bottom with an outlet opening opposite the inlet opening.

[0017] More specifically, the air flowing within the end section of the main channel is moved in such a way as to give it a turbulent motion. In this way, the filaments are propelled by the air and intertwine with each other in an essentially random manner to form the aforementioned desired weave of the nonwoven fabric.

[0018] The end section of the main channel extends downwards, and in particular towards the outlet opening, comprises a diffuser with a substantially truncated cone shape.

[0019] The air flowing through it therefore encounters an increase in the channel cross-section and slows down to assume a turbulent motion, mixing and intertwining the filaments flowing within the end section itself.

[0020] The system of the known type provides for a conveyor belt below the deposition station placed below the outlet opening with which the terminal section of the main channel ends to receive the filaments.

[0021] The conveyor belt is moved to feed along a substantially horizontal direction of movement the filaments thus laid to form the non-woven tape.

[0022] Subsequently, the non-woven tape thus obtained undergoes further processing steps such as pressing and is then moved to a winding station where the tape is wound around a support core to form reels of non-woven fabric, allowing it to be quickly stored and transported.

[0023] As is well known, in the cooling station it is necessary to evenly distribute the air over substantially the entire surface area facing the main channel, uniformly cooling the filaments and obviating the risk of the filaments themselves being displaced with respect to their vertical moving direction within the main channel.

[0024] Homogenising means housed within an air expansion chamber, which remains defined within the cooling station, are known from systems currently on the market. Such known homogenising means comprise perforated metal plates, which extend parallel to the vertical extension axis of the plant.

[0025] The plant for the production of non-woven fabric of the known type briefly described so far has proved to be not without its drawbacks in practice.

[0026] The main drawback lies is that maintenance and cleaning operations, in particular of the homogenising means of the cooling station, require several technicians to disassemble the side walls of the cooling station itself, in order to remove scraps of plastic material fed in from the extrusion station together with the filaments.

[0027] Maintenance operations are in fact very frequent, as the unwanted deposit of dust or similar that accumulates on the homogenising means impairs optimal homogenisation of the cooling air, causing a degradation of the finished product.

[0028] A further drawback of the known type of plant is that the aforementioned maintenance operations are very slow, as technicians have to disassemble the side walls of the cooling station in order to access the cooling volume and then proceed to cleaning the channel. Furthermore, once the maintenance operation is complete, it is necessary for the same technicians to reassemble the side walls of the cooling station and ensure that it is completely sealed off from the outside environment.

[0029] Examples of known types of plants which have the aforementioned drawbacks are for example described in prior documents GB853648A, US2019/360138A1, CN102953132A.

SCOPES OF THE INVENTION

[0030] It is a scope of the present invention to provide a plant for the production of non-woven fabric which allows to overcome, at least in part, the drawbacks of the above-mentioned background art.

[0031] A further scope of the invention is to provide a plant for the production of non-woven fabric which allows maintenance to be carried out rapidly.

[0032] A further scope of the present invention is to provide a plant for the production of non-woven fabric which reduces the cost and the number of technicians required to perform maintenance and cleaning operations.

[0033] A further scope of the present invention is to provide a plant for the production of non-woven fabric which allows for optimal cooling of the filaments within the main channel. A further scope of the present invention is to provide a plant for the production of non-woven fabric that is easy to use by operators.

[0034] A further scope of the invention is to make available a plant for the production of non-woven fabric that is structurally completely reliable.

[0035] A further scope of the invention is to provide a plant for the production of non-woven fabric that is functionally completely reliable.

[0036] A further scope of the present invention is to provide a plant for the production of non-woven fabric that is simple and/or inexpensive to manufacture.

[0037] A further scope of the present invention is to provide a plant for the production of nonwoven fabric that is cost-effective to manufacture.

[0038] A further scope of the present invention is to provide a plant for the production of nonwoven fabric that is industrially feasible.

[0039] A further scope of the present invention is to provide a plant for the production of non-woven fabric that is an alternative and/or an improvement over conventional solution. A further scope of the present invention is to provide a plant for the production of non-woven fabric that has an alternative and/or improved configuration, both in terms of construction and in terms of function, with respect to traditional solutions.

[0040] All of these scopes, either singly or in any combination thereof, and others that will result from the description below are achieved, according to the invention, with a plant for the production of non-woven fabric having the features indicated in claim 1.

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention is further described herein in some preferred embodiments thereof, shown for illustrative and non-limiting scopes only with reference to the appended drawings, wherein:

• Figure 1 shows a schematic front view of an embodiment of the nonwoven fabric production plant according to the present invention;
• Figure 2 shows a front view of an enlarged detail of figure 1 concerning a cooling station;
• Figure 3 shows a schematic view of a cooling station of the plant according to the present invention;
• Figure 4 shows a schematic cross-sectional view of the plant cooling station according to the present invention, made along track IV-IV of figure 3;
• Figure 5 is a further view.

DETAILED DESCRIPTION

[0042] With reference to the appended figures, a plant for the production of non-woven fabric according to the present invention has been designated as 1.

[0043] The plant according to the invention is intended to be advantageously used for the production of non-woven fabric of different types and materials, such as in particular spunbond made of plastic material, for example polypropylene and/or polyethylene, and in particular polyethylene terephthalate (PET in the technical industry jargon).

[0044] In the following, reference will be made to a plant 1 for the production of nonwoven plastic material, in accordance with the preferred embodiment illustrated in the attached figures. However, the plant 1 of the present invention may also be advantageously employed for the production of non-wovens of other types, which are in themselves well known to the person skilled in the art and therefore not described in detail below.

[0045] Therefore, in the following the term "non-woven fabric" is to be understood as a substantially tape-like material composed of a plurality of filaments compressed on top of each other in a substantially random manner. Non-woven fabric (TNT) is the generic term used in the technical field of reference to indicate an industrial product similar to a fabric, but obtained by processes other than weaving (which involve the crossing of warp and weft threads on a loom) and knitting. In fact, in a non-woven fabric, the fibres and/or filaments present a random pattern, without the identification of any orderly structure, typically filaments and/or fibres are arranged in layers or criss-crossed, which are joined together mechanically (e.g. with needles, by needle-punching), or with adhesives or by thermal processes. Sometimes the term is also referred to in English as 'nonwoven'.

[0046] In particular, nonwoven fabric is normally composed of a plurality of plastic filaments joined together by mechanical action, e.g. by crushing.

[0047] The nonwoven fabric production facility according to the invention comprises a support structure 2 provided with a main channel 3, which extends along a vertical axis Y from an upper inlet 4 to a lower outlet 5.

[0048] Advantageously, the support structure 2 is intended to rest on the ground and preferably is made of a durable metal material, such as steel and in particular stainless steel (inox), such as for example AISI 304 steel or AISI 431 steel.

[0049] More specifically, the main channel 3 extends vertically along the aforementioned vertical Y-axis.

[0050] In the following, it is to be understood that the main channel 3 may be delimited by a substantially tubular body defined, in accordance with the preferred embodiment illustrated in the attached figures, by a plurality of substantially tubular sections vertically aligned with each other along the vertical axis Y and susceptible to be crossed by filaments (as described in detail below) for their treatment.

[0051] The plant 1 comprises a feeding station 6 located above the main channel 3 and in communication with the upper inlet 4 for feeding filaments forming a non-woven fabric into the main channel 3.

[0052] Preferably, the feeding station 6 comprises molten plastic forming means placed in flow connection with the upper inlet 4 of the main channel 3 and comprising an extruder (in itself well known to the person skilled in the art and therefore not described in detail below), preferably supported by the support structure 2, capable of forming a continuous flow of molten plastic material and an extrusion head 29 mechanically supported by the support structure 2, placed in fluid connection with the extruder and provided with an extrusion plate facing the upper inlet 4 of the main channel 3.

[0053] The extrusion plate of the extrusion head 29 of the feeding station 6 is advantageously provided with a plurality of through-holes, which are susceptible to be traversed by the flow of molten plastic material to form filaments.

[0054] Operationally, the filaments thus formed pass through the upper inlet 4 and enter the main channel 3 to allow them to be processed through a plurality of operating stations, as described in detail below.

[0055] Advantageously, the plant 1 object of the present invention comprises a fume ejection station provided inferiorly to the feeding station 6, to eject from the main channel 3 any fumes produced during the extrusion of the plastic material from the extrusion head 29 through a chimney (not illustrated), which connects the main channel 3 of the plant 1 with the external environment.

[0056] More in detail, the fume ejection station comprises at least one ejection channel placed to intercept the main channel 3, in particular placed in fluid communication with the extrusion plate of the extrusion head 29, in order to convey the fumes produced by the latter towards said chimney.

[0057] The ejection channel is intended to convey the fumes and vapours produced by the molten plastic material, extruded in filaments from the extrusion head, which could adhere to the inner walls of the main channel 3, forming fouling.

[0058] Preferably, the fume ejection station further comprises a heat exchanger of the water-air type for cooling the fumes and vapours coming from the extrusion head 29 of the feeding station 6 and for collecting any condensate fluid formed as a result of such cooling. Suitably, the plant 1 comprises a cooling station 8, which is placed along said main channel 3 inferiorly to the feeding station 6.

[0059] The cooling station 8 comprises a containment body 11 extending along the vertical axis Y between an upper end 19 and a lower end 20 and extends around the vertical axis Y delimiting a cooling chamber 12 within the main channel 3.

[0060] In accordance with the preferred embodiment illustrated in the attached figures, the cooling chamber 12 preferably corresponds to a first section of the main channel 3.

[0061] Advantageously, the cooling station 8 comprises two containment bodies 11 opposed with respect to the vertical axis Y, in accordance with the attached Figure 1. Therefore, all features described below with reference to a containment body 11 of the cooling station 8 are intended to be described for both containment bodies 11 of the preferred embodiment.

[0062] The cooling station 8 further comprises cooling means in fluid connection with the cooling chamber 12 suitable for introducing into the cooling chamber 12 a first air flow 10 to cool filaments susceptible to pass through the cooling chamber 12.

[0063] Preferably, the cooling station 8 is provided with at least a first outlet opening 9 which places the cooling chamber 12 of the main channel and the expansion chamber defined by the containment body 11 in fluid connection.

[0064] In accordance with the preferred embodiment illustrated in the appended Figures, the first outlet opening 9 is provided in correspondence with an inner wall 21 of the containment body 11 which delimits the main channel 3 and in particular at least partially defines the cooling chamber 12.

[0065] More in detail, the first outlet opening 9 is advantageously realised by means of a plurality of through holes cut on the inner wall 21, in correspondence with the first section of the main channel 3.

[0066] Differently, in accordance with a further embodiment of the plant 1 not illustrated in the appended figures, the inner wall 21 of the containment body 11 can be realised by means of a grid, or a honeycomb wall, whose substantially honeycomb-shaped openings define the aforementioned first outlet opening 9.

[0067] Advantageously, the cooling station 8 comprises ventilation means (not illustrated) placed in fluid connection with the first outlet opening 9 to feed the first air flow 10 into the cooling chamber 12, in particular through the expansion chamber defined by the containment body 11.

[0068] Preferably, the ventilation means comprise a rotary fan, of a well-known type to a person skilled in the art and therefore not described in detail below. Such a fan is configured to generate the first air flow 10 and feed it into the cooling chamber 12 through the first outlet opening 9. Furthermore, the ventilation means preferably comprise a heat exchanger interposed between the fan and the first outlet opening 9.

[0069] More in detail, the heat exchanger is placed to intercept the first air flow 10 generated by the fan and is capable of varying the temperature and humidity of the first air flow 10 itself.

[0070] In accordance with a preferred embodiment of the present invention, the heat exchanger is a water-air type, in particular a heat exchanger of the shell and tube water-air type. Preferably, the heat exchanger is capable of bringing the first air flow 10 to a constant temperature between 20°C and 30°C and in particular between 22°C and 25°C. Preferably, the heat exchanger is mechanically supported by the support structure 2 of the plant 1 in a raised position and substantially aligned with the first outlet opening 9 of the containment body 11.

[0071] Appropriately, the cooling station 8 comprises said containment body 11 developing along said vertical axis Y between an upper end 19 and a lower end 20, and extending around said vertical axis Y delimiting at least said cooling chamber 12 within said main channel 3 and defining internally at least one expansion chamber 7.

[0072] Appropriately, the containment body 11 extends between an inlet opening 17 (visible on the right in the attached Figures 2, 3) and an outlet opening 9 (visible on the left in the attached Figures 2, 3).

[0073] The plant 1 comprises cooling means in fluid connection with said expansion chamber and with said cooling chamber 12 and suitable for introducing into said cooling chamber 12 at least a first air flow 10 to cool the filaments susceptible to pass through said cooling chamber 12.

[0074] The expansion chamber 7 is configured to receive the first air flow rate 10 generated by the cooling means and to allow an expansion thereof, in order to slow down its speed to obtain a more homogeneous cooling of the filaments.

[0075] For this scope, the plant 1 comprises homogenising means 13 housed within said expansion chamber 7 and configured to intercept said first air flow 10 and generate a second air flow 14 substantially homogeneous at least parallel to said vertical axis Y. Suitably, said containment body 11 comprises at least one door 51 movable between a closed position, in which it obstructs a side opening 50 of said containment body 11 and an open position, in which it frees said side opening 50 and allows the extraction and/or insertion of said homogenising means 13 from within said expansion chamber 7 for a maintenance and/or cleaning thereof.

[0076] In this way, the system according to the invention allows to extract the homogenising means 13 quickly and easily, obviating the need to disassemble the containment body 11 of the cooling station 8.

[0077] Preferably, the side opening 50 of the containment body 11 is substantially quadrangular in shape and preferably substantially rectangular.

[0078] Advantageously, said homogenising means 13 comprise at least one grid 15 and/or a panel slidingly inserted within said expansion chamber 7 of said containment body 11.

[0079] More in detail, said at least one grid 15 of said homogenising means 13 comprises at least one perimeter support frame 52, slidingly inserted into a corresponding seat 53 obtained within said expansion chamber of said containment body 11.

[0080] Appropriately, the support frame 52 defines a frame for the corresponding grid 15 of the homogenising means 13.

[0081] Advantageously, as clearly visible in the preferred embodiment illustrated in the attached Figure 5, the support frame 52 is provided with a substantially polygonal and preferably quadrangular cross-section.

[0082] Preferably, as anticipated and described above, said homogenising means 13 comprise two or more grid 15 e\or panels arranged parallel to each other and slidingly inserted within said expansion chamber 7 of said containment body 11.

[0083] Preferably, said door 51 is rotatably constrained to an outer side wall of said containment body 11 and is movable between the open position and the closed position by rotating about an axis of rotation parallel to said vertical axis Y.

[0084] Advantageously, the cooling station 8 of the installation 1 comprises at least one hinge 55 arranged laterally to the side opening 50 and fixed on one side to the containment body 11 and on the other side to said door 51.

[0085] Advantageously, the installation 1 comprises locking means mechanically associated with said door 51 and operable to be moved between a locking configuration in which they lock said door 51 in said closed position and a free position in which they free said door 51 to be moved in said open position.

[0086] Preferably, said locking means are electrically connected to at least one electronic control unit and are susceptible to being activated upon receipt of at least one electrical control signal from said electronic control unit.

[0087] Advantageously, the locking means comprise at least one electrically activatable movable actuator, such as, for example, a piston configured to be moved approaching and moving away from the door 51 at its closed and/or open position.

[0088] Advantageously, the movement of the door 51 around the hinge 55 can be manually actuated by an operator to perform desired maintenance or cleaning operations.

[0089] In order to be able to understand from the outside whether the homogenizing means need maintenance or cleaning, without the need to open the containment body 11, said door 51 is advantageously provided with at least one portion 54 at least partially transparent aligned with said homogenising means 13 to make said homogenising means 13 visible from the outside.

[0090] More in detail, the portion 54 has a substantially rectangular shape and is made of transparent material, such as in particular Plexiglas, glass, or similar.

[0091] Advantageously, the plant 1 according to the invention comprises compacting means, not illustrated in the annexed figures, operatively associated with said homogenising means 13 and configured to compact said grids 15 together within said expansion chamber 7.

[0092] More in detail, the compacting means comprise at least one further actuator placed at a crossing of the containment body 11 and configured to be moved in rebate against at least one grid 15 of the homogenizing means to compact said homogenising means 13 inside the expansion chamber 7.

[0093] Advantageously, said compacting means are operable between a release configuration, in which they release said homogenising means with said door 51 in the open position and a compacting configuration in which they compact said homogenising means with said door in the closed position.

[0094] Preferably, the compacting means are also electrically connected to the electronic control unit and are activated upon receipt of an electrical control signal.

[0095] Advantageously, the electronic control unit comprises at least an electronic microcontroller, suitably programmed and equipped with at least one user interface such as in particular a keyboard and/or a touch screen configured to receive an input signal from an operator, process it and send the corresponding control signal to the locking means and/or the compaction means.

[0096] In accordance with an embodiment of the present invention and with particular reference to the annexed Figure 2, the cooling station 8 of the plant 1 according to the invention comprises at least one dividing wall 18 extending in projection from said inlet opening 17, defining a first expansion zone 7' provided with a first extension defined between said upper end 19 and said dividing wall 18 and a second expansion zone 7' provided with a second extension between said dividing wall 18 and said lower end 20 different from said first extension.

[0097] Preferably, in accordance with said embodiment, the ratio between said first extension of said first expansion zone 7' and said second extension of said second expansion zone 7' is between 0.4 and 0.7 and preferably between 0,5 and 0,6 and even more preferably about 0.,56 to 0,57.

[0098] In other words, advantageously, the first extension of the first expansion zone 7' is about 0,2 to 0,5 of the total extension of the expansion chamber 7 between the upper end 19 and the lower end 20 of the containment body, and preferably about 0,4 of the total extension and even more preferably about 0,37 to 3,38.

[0099] Advantageously, said dividing wall 18 extends between a first end 18' extending from said inlet opening 17, a second end 18' placed at the division of at least one of said grids 15. Advantageously, the dividing wall 18 transversely divides at least one grid 15 of the homogenising means 13. Preferably, the dividing wall 18 divides at least 2/3 of the total number of grids 15 of the homogenising means.

[0100] Preferably, the homogenising means 13 comprise from five to ten grids 15 and suitably, the dividing wall 18 transversely divides at least two to five grids 15.

[0101] In particular, in accordance with the embodiment illustrated in the attached figures, the dividing wall 18 transversally divides at least five grids 15 of the seven grids 15 of the homogenising means 13.

[0102] Preferably, the dividing wall 18 is made of a sheet metal. Advantageously, the sheet metal of the dividing wall 18 is provided with a substantially Z-folded cross-section.

[0103] Preferably, each grid 15 of the homogenising means 13 may comprise more than one sheet of wires 16, 16' interwoven with each other in a woven manner. In particular, the sheets are side-by-side and mechanically fastened together to form said grid 15. Advantageously, each grid 15 comprises at least two and preferably at least three sheets of woven wires 16, 16'.

[0104] In accordance with the embodiment illustrated in the attached Figure 2, the cooling station 8 comprises a barrier element 25 housed within the expansion chamber 7 of the containment body 11.

[0105] In more detail, the barrier element 25 is interposed between the inlet opening 17 and the homogenising means 13 and is advantageously configured to intercept the first air flow rate 10 entering from the inlet opening 17 and preferably lower its velocity before it reaches the at least one grid 15.

[0106] Suitably, the barrier element 25 defines at least one passage slot 26 for the passage of the first air flow rate 10. Preferably, the barrier element 25 defines two passage slots 26, a first passage gap with the upper end 19 of the containment body 11 and a second passage gap with the lower end 20 of the same containment body 11.

[0107] Advantageously, the barrier element 25 is substantially tile-shaped and extends parallel to the vertical axis Y within the expansion chamber 7 of the cooling station 8. Advantageously, the plant 1 subject matter of the present invention comprise a stretching station 27 provided with a stretching channel 28 extending along said vertical axis Y mechanically associated with a lower edge of the containment body 11. Advantageously, the plant 1 object of the present invention further comprises a deposition station 30 located inferiorly to the stretching station 27, along the main channel 3 and terminating with the filament lower outlet 5. The deposition station 30 suitably comprises a diffuser 31. The diffuser 31 of the deposition station 42 extends wideningly from the stretching station 27, terminating with the filament lower outlet 5 for depositing filaments onto a conveyor belt 32.

[0108] Operationally, the filaments passing through the diffuser 31 of the deposition station 30 tend to intertwine with each other and are therefore deposited on the conveyor belt 32 in the form of a nonwoven tape.

[0109] It is clear from the foregoing that the plant for producing nonwoven fabric according to the invention is particularly advantageous in that:

• it is able to overcome, at least in part, the drawbacks of the above-mentioned known technique;
• it allows the cooling station to be serviced quickly and easily;
• it allows to generate a homogeneous cooling air flow rate over the entire extent of the cooling chamber of the main channel;

• is functionally completely reliable
• is simple and/or economical to manufacture;
• is economically advantageous;
• is industrially feasible;
• is alternative and/or improved to traditional solutions;
• has an alternative and/or improved configuration, both in terms of construction and function, compared to traditional solutions.

[0110] The present invention has been illustrated and described in a preferred embodiment, but it is understood that variations in execution may be made to it in practice, without, however, going beyond the scope of protection of this patent for industrial invention.

Claims

1. Plant for the production of non-woven fabric, comprising:

- a support structure (2) provided with a main channel (3) extending along a vertical axis (Y) from an upper inlet (4) to a lower outlet (5);

- a feeding station (6) placed above said main channel (3) and communicating with said inlet (4) to introduce filaments for forming a non-woven fabric into said main channel (3);

- a cooling station (8), which is located along said main channel (3) below said feeding station (6) and comprises:

- a containment body (11) extending along said vertical axis (Y) between an upper end (19) and a lower end (20), and extends around said vertical axis (Y) delimiting at least a cooling chamber (12) inside said main channel (3) and internally defining at least an expansion chamber (7);

- cooling means in fluid connection with said expansion chamber and with said cooling chamber (12) and suitable for introducing into said cooling chamber (12) at least a first air flow (10) for cooling filaments (7) capable of passing through said cooling chamber (12);

- homogenising means (13) housed inside said expansion chamber and configured to intercept said first air flow (10) and generate a second substantially homogeneous air flow (14) at least parallel to said vertical axis (Y);

characterized in that said containment body (11) comprises at least one door (51) movable between a closing position, in which it obstructs a side opening (50) of said containment body (11) and an opening position, in which frees said side opening (50) and allows the extraction and/or insertion of said homogenising means (13) from/into said expansion chamber (7) for their maintenance and/or cleaning.

2. Plant for the production of non-woven fabric according to claim 1, characterized in that said homogenising means (13) comprise at least one grid (15) and/or panel slidably inserted inside said expansion chamber (7) of said containment body (11).

3. Plant for the production of non-woven fabric according to claim 2, characterized in that said at least one grid (15) of said homogenising means (13) comprises at least one perimeter support frame (52), slidably inserted in a corresponding seat (53) obtained inside said expansion chamber of said containment body (11).

4. Plant for the production of non-woven fabric according to claim 3, characterized in that said homogenising means (13) comprise two or more grids (15) and/or panels arranged parallel to each other and slidably inserted inside said expansion chamber (7) of said containment body (11).

5. Plant for the production of non-woven fabric according to one or more of the preceding claims, characterized in that said door (51) is rotatably constrained to an external side wall of said containment body (11) and is movable between the opening and closing position by rotating around an axis of rotation parallel to said vertical axis (Y).

6. Plant for the production of non-woven fabric according to claim 5, characterized in that it comprises locking means mechanically associated with said door (51) and which can be activated to be moved between a locking configuration, in which they lock said door (51) in said closed position and a free position in which they free said door (51) to be moved into said open position.

7. Plant for the production of non-woven fabric according to claim 6, characterized in that said locking means are electrically connected to at least one electronic control unit and can be activated following the reception of at least one electric control signal by said electronic control unit.

8. Plant for the production of non-woven fabric according to one of the preceding claims, characterized in that said door (51) is equipped with at least one portion (54) at least partially transparent and aligned with said homogenising means (13) to make said homogenising means (13) visible from the outside.

9. Plant for the production of non-woven fabric according to one or more of the preceding claims, characterized in that it comprises compacting means, operatively associated with said homogenising means (13) and configured to compact said grids (15) together at the inside of said expansion chamber (7).

10. Plant for the production of non-woven fabric according to claim 9, characterized in that said compacting means can be operated between a release configuration, in which they release said homogenization means with said door (51) in the open position and a compacting configuration in which they compact said homogenizing means with said door in the closed position.

11. Plant for the production of non-woven fabric according to one or more of the preceding claims, characterized in that said support frame (52) defines a frame for said corresponding grid (15) of said homogenising means (13).

12. Plant for the production of non-woven fabric according to one or more of the preceding claims, characterized in that said cooling station (8) comprises at least one hinge (55) arranged laterally to the opening (50) and fixed on one side to said containment body (11) and on the other to said door (51).

13. Plant for the production of non-woven fabric according to one or more of the preceding claims, characterized in that the movement of the door (51) around the hinge (55) is carriable out manually by an operator to carry out the desired maintenance or cleaning operations.

14. Plant for the production of non-woven fabric according to one or more of the preceding claims, characterized in that said electronic control unit comprises at least one electronic microcontroller, programmed and equipped with at least one user interface such as in particular a keyboard and/or a touch screen configured to receive an input signal from an operator, process it and send the corresponding command signal to the locking means and/or to the compacting means.

Drawing