Spinneret for multi-row coaxial spun-bond and / or melt-blown type production facility

Abstract

To provide a spinneret of a multi-row coaxial spun-bond and / or melt-blown type production facility adapted to enable distribution of a polymerized fluid in an output from the production facility in an extrusion polymerization filament form to obtain a non-woven fabric.SOLUTION: In a spinneret (1) of the multi-row coaxial spun-bond and / or melt-blown type production facility, at least one of a plurality of dispensation shafts (2a) of an acceleration tube defines a first angle of inclination (α') other than 90° to a main plane (1b), and at least one of the dispensation shafts (2a) of an acceleration tube (2) of a second lateral array (2'') defines a second angle of inclination (α'') different from the first angle of inclination (α') to the main plane (1b).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a spinneret for a multi-row coaxial spunbond and / or meltblown production installation of the type specified in the preamble of the first claim.

[0002] In particular, the present invention relates to an end portion of a multi-row coaxial spunbond and / or meltblown type production installation adapted to allow distribution of a polymeric fluid at the output from the production installation in the form of extruded polymeric filaments to obtain a nonwoven fabric. [Background technology]

[0003] As is known, nonwoven fabrics, or NWFs (non-woven fabrics), are industrial products similar to woven fabrics, but realized by processes other than weaving and knitting. Thus, in nonwoven fabrics, the fibers have a random pattern without any discernible ordered structure, while in woven fabrics, the fibers have two predominant, orthogonal directions, usually called weft and warp.

[0004] Currently, several products, including NWFs, are manufactured depending on the manufacturing techniques used, primarily related to the application in which the product itself will be utilized.

[0005] In particular, a distinction is made between high quality NWFs for hygiene products and low quality NWFs used especially for geotexing.

[0006] From a technical point of view, nonwoven fabrics can be basically divided into spunlace, spunbond, and multi-row coaxial or cusp meltblown fabrics.

[0007] Spunlace fabrics undergo a process that gives them isotropic resistance. Thanks to this property, the possibility of producing them in a variety of materials such as viscose, polyester, cotton, polyamide, and microfiber, and the two available finishes (smooth or porous) and the many smooth or printed colors, spunlace is suitable for both the hygiene sector and the automotive, beauty, industrial, and single-use sectors.

[0008] Spunbond, typically made from polypropylene, is a nonwoven fabric that finds multiple applications in agriculture, hygiene, construction, furniture, mattresses, and other related fields. With appropriate treatment, it is possible to create a range of highly specialized products for each field: fluorescent, soft calendared, dust mite resistant, fire resistant, antibacterial, antistatic, UV resistant, and more. Numerous finishes may be applied to spunbond, such as printing, laminating, flexographic print laminating, and self-adhesive.

[0009] A spunbond nonwoven production facility essentially includes at least one inlet conduit for polymeric material, a polymer extrusion head, a polymer distributor or breaker plate, and a spinneret adapted to produce the actual spunbond yarns that are deposited on a conveyor belt.

[0010] The above elements are each positioned accordingly and next to each other to allow for polymer processing and distribution of the NWF spunbond.

[0011] More specifically, the polymer inside the dispensing conduit is forced towards the extrusion head under pressure and at elevated temperatures, typically above 200° C. At this point, pressure control is typically performed, for example using a pressure switch, to ensure the continuity of the output yarn and the accuracy of the deposition process.

[0012] The extrusion head distributes the polymer along a distribution surface through which the molten polymer reaches the distributor. Between the distributor or breaker plate and the extrusion head there is a filter made of steel sheet with a thickness usually varying between 0.8 mm and 1.6 mm, containing a fine mesh with a nominal size, for example, comprised between 20 μm and 110 μm. Essentially, the filter is therefore a stretched net.

[0013] After passing inside the filter, the molten polymer enters a distributor, which then directs the polymer to the spinneret where it is extruded into filaments that make up the NWF spunbond. Specifically, the filter has the purpose of blocking any incompletely melted or in some cases larger particles or polymer pigments that may enter the spinneret and block the extremely small extrusion holes of the NWF.

[0014] NWF meltblown fabrics are produced using specialized dies to achieve higher technical properties than the aforementioned TNT. In fact, meltblown fabrics are characterized by fibers with a high filtration power for both liquid and gaseous substances.

[0015] A meltblown nonwoven production facility consists of a box that surrounds the meltblown fiber manufacturing device and all the parts necessary for the process to function optimally.

[0016] Known cusp meltblown production equipment includes an extrusion head, a cusp distributor, and air blades.

[0017] Multi-row coaxial meltblown production equipment provides for the polymer emerging from tubes arranged in rows to be stretched in a coaxial fashion by air passing from the outside of the tubes and pushing the fibers downward.

[0018] In particular, multi-row coaxial meltblown production equipment comprises components defining coaxial bores adapted to accommodate at least a portion of the aforementioned tubes arranged in rows and coaxially passing inside the bores to allow for the diffusion of polymerization fluid and simultaneously allow for the diffusion of air or gas from at least a portion of the bores.

[0019] These production facilities typically include a device called a spin pack, which contains several different components adapted to interact with each other. The spin pack typically consists of a spinneret and one or more diffusion devices, including a component called an air plate. Summary of the Invention

[0020] The described technique has several important drawbacks.

[0021] In particular, nonwoven layers produced with currently known dies are incapable of producing layers that perform well, especially when subjected to traction forces in various directions.

[0022] Indeed, while nonwovens made in this way are very robust along the main direction of development of the production equipment, they are not so robust perpendicular to that direction.

[0023] The consequences of this weakness are very significant, for example, in the manufacture of diapers, the latter of which is often less than 5 g / m 2 The spunbonded polyester polyester film must be made at a very low weight, equivalent to about 100g, and must include a sandwich structure having two spunbonded layers and a central meltblown layer that is primarily used to retain liquid.

[0024] The latter layer is usually 1-2 g / m 2 and often break due to weakness along several directions, the tear thus compromising the liquid tightness and primary function of the diaper.

[0025] In this context, the technical problem underlying the present invention is to devise a spinneret for a multi-row coaxial spunbond and / or meltblown production installation that is able to substantially avoid at least some of the aforementioned drawbacks.

[0026] Within this technical challenge, it is an important object of the present invention to realize a spinneret for a multi-row coaxial spunbond and / or meltblown production installation that makes it possible to produce robust nonwoven membranes or layers in different directions, in particular perpendicular to each other.

[0027] Another important object of the present invention is to provide a spinneret for a multi-row coaxial spunbond and / or meltblown type production equipment that allows for the realization of a robust diaper resulting from the interlocking of the different layers formed by the production equipment.

[0028] The technical problem and the identified object are achieved by a spinneret for a multi-row coaxial spunbond and / or meltblown type production installation as claimed in the attached claim 1.

[0029] Preferred embodiments are highlighted in the dependent claims. [Brief explanation of the drawings]

[0030] The features and advantages of the present invention will become clearer from the following detailed description of preferred embodiments of the invention, with reference to the accompanying drawings, in which:

[0031] [Figure 1] 1 is a simplified diagram of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, in which acceleration conduits with opposite or complementary inclination angles are present in different rows. [Figure 2] FIG. 10 is a simplified diagram of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, wherein the acceleration conduits of the second row define a second inclination angle perpendicular to the main plane and equal to 90°. [Figure 3] FIG. 1 is a side view of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, in a side view, in which the rows of acceleration conduits are made from tubes of the multi-row coaxial meltblown production facility that terminate in the same plane as the second end of the spinneret. [Figure 4] FIG. 1 is a side view of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, in a side view, in which the rows of acceleration conduits are made from tubes of the multi-row coaxial meltblown production facility having terminal ends that protrude from the second end of the spinneret. [Figure 5] 1 is a diagram of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, the outer surface of which is contoured like the inner surface. [Figure 6-1] Figure 6a is a cross-sectional view of a profile with a first concave configuration of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production installation according to the present invention, with the convex portion highlighted by hatching, and Figure 6b is a cross-sectional view of a profile with a second concave configuration of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production installation according to the present invention, with the convex portion highlighted by hatching. [Figure 6-2] Figure 6c is a cross-sectional view of a profile having a third concave configuration of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, with the convex portions highlighted by hatching; Figure 6d is a cross-sectional view of a profile having a fourth convex configuration of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, with the convex portions highlighted by hatching; Figure 6e is a cross-sectional view of a profile having a fifth convex configuration of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, with the convex portions highlighted by hatching; Figure 6f is a cross-sectional view of a profile having a sixth concave configuration of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, with the convex portions highlighted by hatching; [Figure 6-3]Figure 6g is a cross-sectional view of a seventh concave configuration of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production system according to the present invention, with the convex portion highlighted by hatching. Figure 6h is a cross-sectional view of an eighth concave configuration of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production system according to the present invention, with the convex portion highlighted by hatching. Figure 6i is a cross-sectional view of a ninth concave configuration of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production system according to the present invention, with the convex portion highlighted by hatching. Figure 6j is a cross-sectional view of a tenth concave configuration of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production system according to the present invention, with the convex portion highlighted by hatching. [Figure 7]Figure 7a is a perspective view of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, the acceleration conduit having an outer surface in the form of a cylinder and a profile in the form of Figure 6a. Figure 7b is a perspective view of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, the acceleration conduit having an outer surface in the form of a cylinder and a profile in the form of Figure 6b. Figure 7c is a perspective view of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, the acceleration conduit having an outer surface in the form of a cylinder and a profile in the form of Figure 6c. Figure 7d is a perspective view of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, the acceleration conduit having an outer surface in the form of a cylinder and a profile in the form of Figure 6d. Figure 7e is a perspective view of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, the acceleration conduit having an outer surface in the form of a cylinder and a profile in the form of Figure 6e. Figure 7f is a perspective view of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, the acceleration conduit having an outer surface that has a cylindrical shape and a profile in the form of Figure 6f; Figure 7g is a perspective view of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, the acceleration conduit having an outer surface that has a cylindrical shape and a profile in the form of Figure 6g; Figure 7h is a perspective view of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, the acceleration conduit having an outer surface that has a cylindrical shape and a profile in the form of Figure 6h; and Figure 7i is a perspective view of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, the acceleration conduit having an outer surface that has a cylindrical shape and a profile in the form of Figure 6i. FIG. 7j is a perspective view of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production installation according to the present invention, the outer surface of which has a cylindrical configuration and the profile of which has the configuration of FIG. 6j.

[0032] [Figure 8]Figure 8a is a cross-sectional view of the termination of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production system according to the present invention, the outer surface of which has a similar profile to the inner surface, and the conduits have the same profile on the same column and alternating profiles on the same row. Figure 8b is a cross-sectional view of the termination of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production system according to the present invention, the outer surface of which has a similar profile to the inner surface, and the conduits have the same profile. Figure 8c is a cross-sectional view of the termination of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production system according to the present invention, the outer surface of which has a similar profile to the inner surface, and the conduits abut and alternate with columns of conduits defining each circular profile. FIG. 8d is a cross-sectional view of the end of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production installation according to the present invention, in which the outer surface has a similar contour to the inner surface, and the conduits have the same contour on the same column and alternating concave and convex contours on the same row, respectively. [Figure 9] Figure 9a is a cross-sectional view of the end of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, the outer surface of which is cylindrical and the conduits have the same concave profile; Figure 9b is a cross-sectional view of the end of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, the outer surface of which is cylindrical and the conduits have the same triangular convex profile; Figure 9c is a cross-sectional view of the end of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, the outer surface of which is cylindrical and the conduits have the same generally rectangular convex profile; and Figure 9d is a cross-sectional view of the end of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention, the outer surface of which is cylindrical and the conduits have the same generally star-shaped concave profile. [Figure 10]Figure 10a is a cross-sectional view of the end of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production system according to the present invention, the outer surface of which is cylindrical and the conduits have the same concave profile, alternating in a checkerboard pattern with conduits having a circular profile; Figure 10b is a cross-sectional view of the end of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production system according to the present invention, the outer surface of which is cylindrical and the conduits have two different concave profiles, alternating in a checkerboard pattern with conduits of different profiles; and Figure 10c is a cross-sectional view of the end of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production system according to the present invention, the outer surface of which is cylindrical and the conduits have two different, concave and convex, profiles, alternating in a checkerboard pattern with conduits of different profiles. FIG. 10d is a cross-sectional view of the end of an acceleration conduit of a spinneret for a multi-row coaxial spunbond and / or meltblown production installation according to the present invention, in which the outer surface is cylindrical and the conduits have two different profiles, one concave and one convex, with the different profiles alternating in a checkerboard manner. DETAILED DESCRIPTION OF THE INVENTION

[0033] As used herein, when measurements, values, shapes, and geometric references (e.g., perpendicular and parallel) are associated with words such as "approximately" or other similar terms, such as "almost" or "substantially," they are understood to exclude measurement errors or inaccuracies due to production and / or manufacturing tolerances, and in particular to have less than a slight deviation from the associated value, measurement, shape, or geometric reference. For example, when associated with a value, such terms preferably indicate a deviation of no more than 10% from the value itself.

[0034] Additionally, when terms such as "first," "second," "upper," "lower," "primary," and "secondary" are used, they do not necessarily specify a priority in order, relationship, or relative position, but may be used merely to clearly distinguish between different components thereof.

[0035] Unless otherwise specified, and as set forth in the discussion below, terms such as "processing," "calculating," "determining," "computing," or the like, are deemed to refer to the actions and / or processes of a computer or similar electronic computing device that manipulate and / or transform data represented as physical, e.g., electronic, quantities in a computer system and / or memory record with other data that is similarly represented as physical quantities within the computer system, record, or other information storage, transmission, or display device.

[0036] Unless otherwise stated, measurements and data reported herein are taken as originating in the International Standard Atmosphere ICAO (ISO 2533:1975).

[0037] Referring to the drawings, a spinneret for a multi-row coaxial spunbond and / or meltblown type production installation according to the present invention is generally referred to using the reference numeral 1.

[0038] The spinneret 1 is the part of the production equipment from which the polymer filaments made from the polymer fluid are directly discharged. Thus, in a spunbond production equipment, the spinneret 1 is the downstream part of the production equipment adapted to transport the polymer filaments onto a deposition surface to make a nonwoven fabric.

[0039] Basically, the spinneret 1 can therefore be presented as a perforated plate.

[0040] In a multi-row coaxial meltblown production facility, the spinneret 1 may be defined by a spin pack. For example, the spinneret 1 may include a spinneret and an air plate.

[0041] The spinneret further includes a plurality of coaxial holes adapted to receive tubes arranged in rows and passing coaxially inside the holes to allow diffusion of the polymerization fluid and simultaneously allow air or gas from at least some of the holes to diffuse through the air plate.

[0042] In this case, the production installation therefore provides for stretching the polymer emerging from tubes arranged in rows by air passing coaxially from the outside of the tubes and pushing the fibers downwards.

[0043] In either case, preferably the spinneret 1 develops primarily along a main axis 1a, which is an imaginary axis along which the spinneret 1 extends, for example the axis of gravity.

[0044] Furthermore, the spinneret 1 also extends along a main plane 1b, which may be provided, for example, by an intermediate plane that is preferably parallel to the support surface on which the polymeric filaments that make up the nonwoven fabric are deposited.

[0045] The main axis 1a can be parallel to the main plane 1b and in some cases coplanar with it.

[0046] Furthermore, the spinneret 1 defines a vertical axis 1c.

[0047] The vertical axis 1c is preferably perpendicular to the main axis 1a, and therefore is also preferably perpendicular to the main plane 1b. Thus, the vertical axis 1c is preferably oriented perpendicular to the support surface on which the polymerized filaments that make up the nonwoven fabric are deposited, and extends along the spinneret 1 from the upstream side to the downstream side.

[0048] The spinneret 1 therefore comprises at least one first end 10 .

[0049] The first end 10 is adapted to interface with a polymeric fluid distributor of a multi-row coaxial spunbond and / or meltblown production equipment. The first end 10, in turn, is the exposed portion of the spinneret 1 upstream of the spinneret 1 through which the polymeric fluid is delivered.

[0050] For example, the first end 10 can be made by a surface parallel to the main plane 1b that is adapted to be fixed to a distributor of a production facility.

[0051] The spinneret 1 also comprises a second end 11 .

[0052] The second end 11 is located on the opposite side of the spinneret 1 from the first end 10 with respect to the main plane 1b. Furthermore, the second end 11 is the part from which the polymer fluid is discharged from the spinneret 1 in the form of polymer filaments.

[0053] The second end 11 is therefore the exposed portion of the spinneret 1 that is downstream of the spinneret 1 and is adapted to convey the polymerized filaments towards a support surface.

[0054] For example, the second end 11 may be made from a plane parallel to the main plane 1b facing the support surface.

[0055] In either case, the spinneret 1 comprises a plurality of acceleration conduits 2 .

[0056] If the spinneret 1 is part of a spunbond system, the acceleration conduit 2 may be made by a simple exit through-hole through which the polymer fluid is stretched to create the filaments.

[0057] If the spinneret 1 is part of a multi-row coaxial meltblown production facility, the acceleration conduit 2 may be made from a tube through which the polymer fluid is stretched to create filaments, as shown, for example, in Figures 3-4. It is important to note that in this particular case, the end of the tube may be flush with the second end 11 or may protrude from the second end 11 outside the spinneret 1.

[0058] In either case, the acceleration conduits 2 extend at least from a first end 10 to a second end 11. Each of the acceleration conduits 2 therefore extends along its own dispensing axis 2a.

[0059] The dispensing axis 2 a is the axis along which the polymer fluid flows along the acceleration conduit 2 .

[0060] Thus, the acceleration conduits 2 are adapted to each dispense a respective polymer filament along a dispensing axis 2a.

[0061] Furthermore, the acceleration conduits 2 are distributed along a distribution axis 2b, which is preferably transverse to the main axis 1a and the vertical axis 1c. The acceleration conduits 2 are then distributed along the distribution axis 2b so as to realize a first row 2' along the distribution axis 2b.

[0062] Furthermore, the acceleration conduits 2 are also distributed along and parallel to the main axis 1a so as to realize at least a second row 2''.

[0063] Therefore, the second row 2'' is preferably offset along the major axis 1a relative to the first row 2'.

[0064] Furthermore, advantageously, at least one of the dispensing axes 2a of the acceleration conduits 2 of the first row 2' defines a first inclination angle α'.

[0065] A first tilt angle α' is defined relative to the main plane 1b. Furthermore, advantageously, the first tilt angle α' is other than 90°. For example, the first tilt angle α' may be comprised between 60° and 90°.

[0066] Furthermore, at least one of the dispensing axes 2a of the acceleration conduits 2 of said second row 2' defines a second tilt angle α''.

[0067] A second tilt angle α'' is also defined relative to the main plane 1b. Furthermore, advantageously, the second tilt angle α'' is different from the first tilt angle α'.

[0068] This means that at least one pair of acceleration conduits 2 of different rows 2', 2'' are inclined differently and dispense polymer filaments in such a way that the polymer filaments can, for example, converge with other polymer filaments.

[0069] In particular, as shown in Figures 1 to 2, preferably, the dispensing axes 2a of all acceleration conduits 2 of the first row 2' and / or the second row 2'' define the same first inclination angle α' and / or the same second inclination angle α'', respectively.

[0070] Even more particularly, one or more of the second tilt angles α″ may be equal to 90°, for example, all second tilt angles α″ as shown in FIG.

[0071] Or again, the second tilt angle α'' may be opposite or complementary to the first tilt angle α', for example as shown in FIG.

[0072] As already mentioned, the acceleration conduit 2 is therefore an element of substantially elongated form, comprising a cavity through which the polymer in liquid state can be filtered in order to enable it to be extruded, in particular from the spinneret 1 .

[0073] The acceleration conduit 2 therefore comprises at least one inner surface 3 .

[0074] The inner face 3 is substantially closed and furthermore extends around the dispensing axis 2a since it actually faces it.

[0075] The inner surface 3 therefore surrounds the cavity.

[0076] Furthermore, the acceleration conduit 2 defines a plurality of contours 4. The contours 4 are identical to one another and are arranged successively along the dispensing axis 2a.

[0077] The contour 4 is therefore substantially formed along the dispensing axis 2a by the inner surface 3 and determines the overall shape of the cavity.

[0078] In particular, the contour 4 is preferably determined on the cross section 2c.

[0079] The cross section 2c is preferably perpendicular to the dispensing axis 2a and is therefore essentially an imaginary plane that cuts the acceleration conduit 2 perpendicularly to the dispensing axis 2a and thereby defines on itself the contour 4 formed by the inner surface 3.

[0080] The contour 4 also defines a first extended area, which is the portion of the two-dimensional space contained within the contour 4.

[0081] Therefore, the contour 4 can preferably be depicted in a circle, which is also determined on the cross section 2c. Naturally, a circle is a trivially imaginary geometric element inside which the contour 4 can be geometrically depicted.

[0082] Furthermore, the circle itself defines a second area of ​​extension on the cross section 2c. The second area of ​​extension is therefore determined by the two-dimensional space contained within the circle, which, as is known, can be calculated using the formula A=π*r 2 can be obtained by

[0083] Advantageously, the contour 4 does not have a shape corresponding to a circle.

[0084] Indeed, advantageously, the first extension area is less than 90% of the second extension area, and even more particularly, preferably, the first extension area is less than 60% of the second extension area.

[0085] Thus, the contour 4 can be made according to various embodiments.

[0086] For example, contour 4 may be a convex shape. As is known, a convex shape is one in which any line segment connecting any two of its points is contained entirely within the shape itself.

[0087] Thus, if the contour 4 is convex, it preferably defines a first dimension 4a and a second dimension 4b.

[0088] The first dimension 4a is the largest dimension that the contour 4 defines in one direction, and the second dimension 4b is the largest dimension in a direction perpendicular to the first dimension 4a.

[0089] Preferably, the second dimension 4b is less than 90% of the first dimension 4a. Even more particularly, the second dimension 4b may be less than 60% of the first dimension 4a.

[0090] Furthermore, the dimensions may refer to a geometrically well-defined contour 4. For example, the convex contour 4 may have the form of an almost equilateral triangle, as shown in Figure 6e, or a generally rectangular shape, possibly with additional slightly rounded sides, as shown in Figure 6d.

[0091] Of course, in the case of a triangle, the first dimension 4a may be given by the height, while the second dimension 4b may be given by the side intersected by the height, and in the case of a rectangle, the dimensions 4a, 4b may correspond to the respective sides.

[0092] In other embodiments, the contour 4 may instead be concave. Dual to being convex, a shape is concave if there is at least one line segment connecting a pair of points of the shape that does not belong entirely to the shape itself.

[0093] Thus, if the contour 4 is concave, it preferably includes at least one convex portion 40. A convex portion 40 is a part of the concave contour 4 that is identifiable within the contour 4 as being at least partially delimited and that has the property of being convex.

[0094] Thus, convex portion 40, like convex contour 4, may also define a third dimension 40a and a fourth dimension 40b.

[0095] The third dimension 40a is substantially the largest dimension in one direction that the convex portion 40 extends, and the fourth dimension 40b is similarly the largest dimension in a direction perpendicular to the third dimension 40a.

[0096] Preferably, the fourth dimension 40b is less than 90% of the third dimension 40a. Even more particularly, the fourth dimension 40b can be less than 60% of the third dimension 40a.

[0097] As previously mentioned, the dimensions may refer to a geometrically well-defined convex portion 40. For example, the convex portion 40 of the contour 4 may have a generally triangular shape, as shown for example in Figure 6h, or a generally rectangular shape, as shown in Figures 6g and 6j, possibly with chamfered sides as in Figure 6a, or even a trapezoidal shape, as shown in Figures 6b-6c.

[0098] Of course, in the case of a triangle, the third dimension 40a may be given by the height, while the fourth dimension 40b may be given by the base below the height. In the case of a rectangle, the dimensions 40a, 40b may correspond to the respective sides.

[0099] More generally, the concave contour 4 may be formed by two or more mutually intersecting convex portions 40. The concave contour 4 may thus define a cross / star-like configuration with three to five points (for example, three as in Figures 6a and 6c, or four as in Figures 6f and 6i, or even five as in Figures 6b and 6j).

[0100] In addition to what has been described, in particular if the acceleration conduit 2 is a tube, it may also be provided with an outer surface 5 .

[0101] The outer surface 5 is also closed. Furthermore, the outer surface 5 extends around the inner surface 3. In that case, the outer surface 5 wraps around the inner surface 3.

[0102] Preferably, the outer surface 5 of the acceleration conduit 2, facing outwards and therefore not in contact with the cavity, is also connected to the inner surface 3 via a wall 6.

[0103] The wall 6 is therefore bounded by the surfaces 3, 5, which therefore define both sides of the wall 6 with respect to the same wall 6.

[0104] The outer surface 6 may therefore be cylindrical, as shown in Figures 7A-7j, 9a-9d, and 10a-10d, or the outer surface 5 may alternatively be contoured like the inner surface 3. In this way, the surfaces 3, 5 define a constant thickness for the wall 6, as shown, for example, in Figures 5 and 8a-8d.

[0105] Of course, the acceleration conduit 2 may also be used with other acceleration conduits 2 to form a group of acceleration conduits 2, for example a pack, for use in a production facility.

[0106] Thus, in various embodiments, the spinneret 1 may comprise multiple acceleration conduits 2 all defining the same contour 4, as in Figures 9a-9d.

[0107] Or, a chain 1 may comprise a number of such acceleration conduits 2 defining respective different contours 4, as in Figures 8a to 8d and 10b to 10d.

[0108] Or again, the spinneret 1 may comprise a plurality of acceleration conduits 2 each defining a circular contour, ie having a conventional contour according to known technology, as in Figures 8c and 8a.

[0109] For example, the spinneret 1 may comprise a number of acceleration conduits 2, each defining a circular profile but with different diameters.

[0110] Of course, the present invention also comprises a multi-row coaxial spunbond and / or meltblown production installation comprising a spinneret 1 as just described according to various possible embodiments.

[0111] The operation of the spinneret 1 for a multi-row coaxial spunbond and / or meltblown production installation described above in structural terms is substantially similar to that of any spinneret of the prior art in the sense that it allows the polymer fluid to be transported along the dispensing axis 2a of each acceleration conduit 2.

[0112] However, the spinneret 1 for a multi-row coaxial spunbond and / or meltblown production facility according to the present invention achieves important advantages.

[0113] Indeed, the polymer filament chains of multi-row coaxial spunbond and / or meltblown production equipment make it possible to create strong nonwoven membranes or layers in various, especially perpendicular, directions relative to each other.

[0114] The fact that the filaments are discharged in different directions at different inclinations makes it possible to achieve robustness of the fabric not only parallel to the main axis 1a but also transverse to it, i.e. parallel to the distribution axis 2b.

[0115] Thus, the spinneret 1 for multi-row coaxial spunbond and / or meltblown production equipment also makes it possible to create a robust diaper, which is more resistant and sturdy, as it is less susceptible to destruction, especially the weaker layers, which are brought about by connecting the various layers formed by the production equipment.

[0116] The invention can be modified to produce various versions that fall within the scope of the inventive concept defined by the claims.

[0117] In this context, all details may be replaced by equivalent elements and materials; the shapes and dimensions may be arbitrary. (Other possible items) (Item 1) A spinneret (1) for a multi-row coaxial spunbond and / or meltblown type production installation, extending along a major axis (1 a) and a major plane (1 b) and defining a vertical axis (1 c) perpendicular to said major axis (1 a) and said major plane (1 b), a first end (10) adapted to interface with a polymerization fluid distributor of a multi-row coaxial spunbond and / or meltblown production equipment; a second end (11) of the spinneret (1) located on the opposite side of the main plane (1b) from the first end (10), through which the polymerization fluid leaves the spinneret (1) in the form of polymerized filaments; and A plurality of acceleration conduits (2) each extending along its own dispensing axis (2a) at least from said first end (10) to said second end (11); adapted to dispense each of said polymeric filaments one by one along said dispensing axis (2a), distributed along a distribution axis (2b) transverse to said major axis (1a) and said vertical axis (1c) to create a first row (2'), and parallel to said major axis (1a) to create at least a second row (2'') offset along said major axis (1a) with respect to said first row (2'); multiple acceleration conduits; In a spinneret comprising: at least one of the dispensing axes (2a) of the acceleration conduits (2) of the first row (2') defines a first inclination angle (α') other than 90° with respect to the main plane (1b); At least one of the dispensing axes (2a) of the acceleration conduits (2) of the second row (2'') defines a second inclination angle (α'') with respect to the main plane (1b), the second inclination angle (α'') being different from the first inclination angle (α'). Spinneret. (Item 2) 2. The spinneret (1) according to item 1, wherein the dispensing axes (2a) of all the acceleration conduits (2) of the first row (2') and / or the second row (2'') respectively define the same first inclination angle (α') and / or the same second inclination angle (α''). (Item 3) Item 1. The spinneret (1) of any one of the preceding items, wherein one or more of the second tilt angles (α″) is equal to 90°. (Item 4) 2. The spinneret (1) according to any one of the preceding items, wherein the second tilt angle (α″) is opposite or complementary to the first tilt angle (α′). (Item 5) 2. The spinneret (1) according to any one of the preceding items, wherein the first tilt angle (α') is comprised between 60° and 90°. (Item 6) One or more of the acceleration conduits (2) have at least one closed inner surface (3) that extends around the dispensing axis (2a) and defines a plurality of identical contours (4) arranged successively along the dispensing axis (2a); the contours (4) are determined on a cross section (2c) perpendicular to the dispensing axis (2a); the contours (4) define a first extension area on the cross section (2c); the contours (4) are delineable within a circle determined on the cross section (2c); the circle defines a second extension area on the cross section (2c); The first extension area is less than 90% of the second extension area; A spinneret (1) according to any one of the preceding items. (Item 7) The spinneret (1) according to the immediately preceding item, wherein the first extension area is less than 60% of the second extension area. (Item 8) 10. The spinneret (1) according to any one of the preceding items, wherein the contour (4) is convex and defines at least a first maximum dimension (4a) and a second maximum dimension (4b) perpendicular to the first dimension (4a) and less than 90% of the first dimension (4a). (Item 9) The spinneret (1) according to the immediately preceding item, wherein the second dimension (4b) is less than 60% of the first dimension (4a). (Item 10) The spinneret (1) according to the immediately preceding paragraph, wherein said contour (4) defines the form of a substantially equilateral triangle or a substantially rectangular shape. (Item 11) 8. The spinneret (1) according to any one of items 6 to 7, wherein the contour (4) is concave and includes at least one convex portion (40) that is discernible within the contour (4) as being bounded by at least a portion of the contour (4) and defines at least a third maximum dimension (40a) and a fourth maximum dimension (40b) that is perpendicular to the third dimension (40a) and is less than 90% of the third dimension (40a). (Item 12) The spinneret (1) according to the immediately preceding item, wherein the fourth dimension (40b) is less than 60% of the third dimension (40a). (Item 13) 13. The spinneret (1) according to any one of items 11 to 12, wherein the contour (4) is formed by two or more of the convex portions (40) intersecting each other. (Item 14) The spinneret (1) according to the previous item, wherein the contour (4) defines a crossing shape having three to five points. (Item 15) A spinneret (1) according to the previous item, comprising a plurality of said acceleration conduits (2) which all define the same contours (4), or contours (4) which differ from one another, and / or one or more of circular type.

Claims

1. A spinneret for a multi-row coaxial spunbond and / or meltblown type production equipment, the spinneret extending along a major axis and a major plane and defining a vertical axis perpendicular to said major axis and said major plane; a first end adapted to interface with a polymerization fluid distributor of a multi-row coaxial spunbond and / or meltblown type production equipment; a second end of the spinneret disposed on an opposite side of the major plane from the first end, where polymerization fluid exits the spinneret in the form of polymerized filaments; and - a plurality of acceleration conduits each extending along its own dispensing axis from at least said first end to said second end; adapted to dispense each of the polymeric filaments one at a time along the dispensing axis; distributed along a distribution axis transverse to said major axis and said vertical axis to create a first row, and parallel to said major axis to create at least a second row offset along said major axis relative to said first row; Multiple acceleration conduits; In a spinneret comprising: at least one of the dispensing axes of the acceleration conduits of the first row defines a first tilt angle other than 90° with respect to the major plane; At least one of the dispensing axes of the acceleration conduits of the second row defines a second inclination angle with respect to the major plane that is different from the first inclination angle. Spinneret.

2. 2. The spinneret of claim 1, wherein the dispensing axes of all the acceleration conduits of the first row and / or the second row define the same first inclination angle and / or the same second inclination angle, respectively.

3. 10. The spinneret of claim 1, wherein one or more of the second tilt angles is equal to 90 degrees.

4. 10. The spinneret of claim 1, wherein the second tilt angle is opposite or complementary to the first tilt angle.

5. 10. The spinneret of claim 1, wherein the first tilt angle is comprised between 60° and 90°.

6. One or more of the acceleration conduits have at least one closed inner surface that extends around the dispensing axis and defines a plurality of identical contours arranged consecutively along the dispensing axis; the contours are determined on a cross section perpendicular to the dispensing axis; the contours define a first extension area on the cross section; the contours are describable within a circle determined on the cross section; and the circle defines a second extension area on the cross section; The first extension area is less than 90% of the second extension area; 6. The spinneret of claim 1.

7. 7. The spinneret of claim 6, wherein the first extension area is less than 60% of the second extension area.

8. 7. The spinneret of claim 6, wherein the profile is convex and defines at least a first maximum dimension and a second maximum dimension that is perpendicular to the first maximum dimension and that is less than 90% of the first maximum dimension.

9. 9. The spinneret of claim 8, wherein the second maximum dimension is less than 60% of the first maximum dimension.

10. 10. The spinneret of claim 9, wherein the profile defines a generally equilateral triangle or a generally rectangular form.

11. 7. The spinneret of claim 6, wherein the contour is concave and includes at least one convex portion discernible within the contour as bounded by at least a portion of the contour and defining at least a third maximum dimension and a fourth maximum dimension perpendicular to the third maximum dimension and less than 90% of the third maximum dimension.

12. 12. The spinneret of claim 11, wherein the fourth maximum dimension is less than 60% of the third maximum dimension.

13. 12. The spinneret of claim 11, wherein the profile is formed by two or more of the convex portions intersecting each other.

14. 14. The spinneret of claim 13, wherein the profile defines a crossing configuration having three to five apexes.

15. 15. The spinneret of claim 14, comprising a plurality of said acceleration conduits all defining the same said contour or contours different from one another, and / or one or more of circular type.

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