Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/253—Formation of filaments, threads, or the like with a non-circular cross section; Spinnerette packs therefor
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D4/00—Spinnerette packs; Cleaning thereof
  • D01D4/02—Spinnerettes
  • D01D4/025—Melt-blowing or solution-blowing dies
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D4/00—Spinnerette packs; Cleaning thereof
  • D01D4/02—Spinnerettes
  • D01D4/027—Spinnerettes containing inserts
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/08—Melt spinning methods
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
  • D04H1/56—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving in association with fibre formation, e.g. immediately following extrusion of staple fibres
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
  • D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
  • D04H3/16—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion

Definitions

• the present invention relates to a spinneret for multi-row coaxial spunbond and/or melt-blown type plant of the type specified in the preamble of the first claim.
• the present invention relates to an end portion of a multi-row coaxial spunbond and/or melt-blown type plant adapted to allow the distribution of polymeric fluid in output from the plant in the form of extruded polymeric filaments to obtain non-woven fabric.
• non-woven fabric As is known, non-woven fabric, or NWF, is an industrial product similar to a fabric but obtained by processes other than weaving and knitting. Therefore, within a non-woven fabric, the fibers have a random pattern, with no identifiable ordered structure while in a fabric the fibers have two prevailing and orthogonal directions between them, usually called weft and warp.
• non-woven fabrics can be basically divided into spunlace, spunbond and multirow coaxial or cusp melt-blown fabrics.
• 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 microfibre, to the two possible finishes, i.e. smooth or perforated, and to the multitude of smooth or printed colours, spunlace is suitable both for the sanitary sector and for the automotive, cosmetic, industrial or single-use sectors.
• Spunbond usually made of polypropylene
• Spunbond is a non-woven fabric that finds multiple applications in the agricultural, sanitary, construction, furniture, mattress and other related sectors.
• Numerous finishes can also be applied to the Spundbond, such as printed, laminated, flexographic printed laminate and self-adhesive.
• the filter After passing inside the filter, the molten polymer enters the distributor that accompanies the polymer towards the spinneret where the polymer is extruded into filaments constituting the NWF spundbond.
• the filter has the purpose of blocking particles or polymer pigments, not perfectly dissolved or in any case larger, which by entering the spinneret could obstruct the extremely small NWF extrusion holes.
• the NWF melt-blown is made through specific dies in order to achieve higher technical characteristics than previous TNTs.
• the melt-blown fabric is characterised by fiber with high filtering power for both liquid and aeriform substances.
• the melt-blown non-woven fabric production plants consist of a box that encloses the melt-blown fiber manufacture device and all the parts that are necessary for the process to function at its best.
• the known cusp melt-blown plants comprise an extrusion head, a cusp distributor, and an air blade.
• the multi-row coaxial melt-blown plants provide for stretching the polymer that comes 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.
• the multi-row coaxial melt-blown type plants comprise components defining coaxial holes, arranged in rows and adapted to house at least part of the aforementioned tubes transiting coaxially inside the holes in such a way as to allow the diffusion of polymeric fluid and, at the same time, to allow the diffusion of air or gas from at least part of the holes.
• these plants include devices, called spin packs, including a plurality of different components adapted to interact with each other.
• a spin pack consists of a spinneret and a diffusion device including one or more components called air plate.
• the layers of non-woven fabric made with the currently known dies do not allow the creation of particularly high-performance layers when placed under traction in different directions.
• non-woven fabrics thus made are very robust along the main development direction of the plant, they are not so perpendicular to that direction.
• the consequence of this weakness is, for example, very impactful in the manufacture of diapers.
• the latter must often be made with very low weights, equal to 5 g/m 2 and include a sandwich structure with two outer spundbond layers and a central melt-blown layer mainly used to retain liquids.
• the latter layer is usually made with weights equal to 1-2 g/m 2 and is often subject to tearing due to weakness along some directions and, therefore, rupture compromises the liquid tightness and the main functionality of the diaper.
• the technical task underlying the present invention is to devise a spinneret for multi-row coaxial spunbond and/or melt-blown type plant capable of substantially obviating at least part of the aforementioned drawbacks.
• Another important object of the invention is to realize a spinneret for multi-row coaxial spunbond and/or melt-blown type plant that allows to realize robust diapers given by the coupling of the different layers formed by the plant.
• the spinneret for multi-row coaxial spunbond and/or melt-blown type plant according to the invention is globally referred to with the numeral 1.
• the spinneret 1 is the portion of the plant from which polymer filaments made from the polymer fluid directly exit. Therefore, in a spunbond plant, the spinneret 1 is the downstream portion of the plant adapted to convey polymeric filaments on a deposition surface to make non-woven fabric.
• the spinneret 1 can be presented as a perforated plate.
• the spinneret 1 can be defined by a spin pack.
• the spinneret 1 may include a spinneret and an air plate.
• the spinneret includes, in turn, a plurality of coaxial holes, arranged in rows, adapted to house tubes passing coaxially inside the holes in such a way as to allow the diffusion of polymeric fluid and, at the same time, to allow the diffusion of air or gas from at least part of the holes, then passing through the air plate.
• the plant provides for stretching the polymer that comes out of tubes, arranged in rows, through the air that, coaxially, passes from the outside of the tube and pushes the fiber downwards.
• the spinneret 1 develops mainly along a main axis 1a.
• the main axis 1a is a virtual axis, for example barycentric, along which the spinneret 1 extends.
• the spinneret 1 also extends along a main plane 1b .
• the main plane 1b can be provided, for example, by an intermediate plane, preferably parallel to the support surface on which the polymeric filaments that make up the non-woven fabric are deposited.
• the main axis 1a may be parallel and in some cases co-planar to the main plane 1b.
• the spinneret 1 defines a vertical axis 1c.
• the vertical axis 1c is preferably perpendicular to the main axis 1a. Hence, the vertical axis 1c is preferably also perpendicular to the main plane 1b. Therefore, the vertical axis 1c is preferably oriented perpendicular to the support surface on which the polymeric filaments that make up the non-woven fabric are deposited and runs along the spinneret 1 from upstream to downstream.
• the spinneret 1 therefore comprises at least one first end 10.
• the first end 10 is adapted to interface with a polymeric fluid distributor of a multi-row coaxial spunbond and/or melt-blown type plant. Then, the first end 10 is the portion of the spinneret 1 exposed upstream of the spinneret 1 on which the polymer fluid is conveyed.
• the first end 10 can be made by a face parallel to the main plane 1b adapted to be constrained to the distributor of the plant.
• the spinneret 1 also comprises a second end 11.
• the second end 11 is arranged at a side of the spinneret 1 opposite the first end 10 with respect to the main plane 1b. Furthermore, the second end 11 is the portion at which the polymer fluid exits from the spinneret 1 in the form of polymer filaments. Therefore, the second end 11 is the portion of the spinneret 1 exposed downstream of the spinneret 1 and adapted to convey polymeric filaments towards the support surface.
• the second end 11 can be made from a face parallel to the main plane 1b facing the support surface.
• the spinneret 1 comprises a plurality of acceleration conduits 2.
• the acceleration conduits 2 can be made by simple outlet through holes through which the polymer fluid is stretched to make the filaments.
• the acceleration conduits 2 can be made of tubes through which the polymer fluid is stretched to make the filaments, as for example shown in Figs. 3-4 . It is important to note that, especially in this case, the termination of the tubes may be flush with the second end 11 or may also protrude from the second end 11 outside the spinneret 1.
• the acceleration conduits 2 extend at least from the first end 10 to the second end 11. Each of the acceleration conduits 2 therefore extends along its own dispensing axis 2a.
• the dispensing axis 2a is the axis along which the polymer fluid flows along the acceleration conduit 2.
• the acceleration conduits 2 are adapted to dispense each a respective polymer filament along the dispensing axis 2a.
• acceleration conduits 2 are distributed along a distribution axis 2b.
• the distribution axis 2b is preferably transverse to the main axis 1a and to the vertical axis 1c. Then, the acceleration conduits 2 are distributed along the distribution axis 2b in such a way as to realize, along the distribution axis 2b, a first row 2' .
• acceleration conduits 2 are also distributed along and parallel to the main axis 1a in such a way as to realize at least a second row 2".
• the second row 2" is, therefore, preferably offset with respect to the first row 2' along the main axis 1a.
• At least one of the dispensing axes 2a of the acceleration conduits 2 of the first row 2' defines a first angle of inclination ⁇ ' .
• the first inclination angle ⁇ ' is defined with respect to the main plane 1b. Furthermore, advantageously, the first angle of inclination ⁇ ' is other than 90°. For example, the first angle of inclination ⁇ ' may be comprised between 60° and 90°. Furthermore, at least one of the dispensing axes 2a of the acceleration conduits 2 of said second row 2' defines a second angle of inclination ⁇ " .
• the second angle of inclination ⁇ " is also defined with respect to the main plane 1b. Furthermore, advantageously, the second inclination angle ⁇ " is different from the first inclination angle ⁇ '.
• At least one pair of acceleration conduits 2 of the different rows 2',2" are differently inclined and thus dispense polymer filaments that can converge, for example, with the other polymer filaments.
• one or more of the second angles of inclination ⁇ " may be equal to 90°, for example all the second angles of inclination ⁇ " as shown in Fig. 2 .
• the acceleration conduit 2 is, as such, an element of substantially elongated shape and including a cavity through which polymer in the liquid state can percolate to allow extrusion, in particular from the spinneret 1.
• the acceleration conduit 2 therefore, comprises at least one inner surface 3.
• the inner surface 3 is substantially closed. Furthermore, it develops around the dispensing axis 2a, since it is in fact facing onto it.
• the inner surface 2 therefore, encloses the cavity.
• the acceleration conduit 2 defines a plurality of outlines 4.
• the outlines 4 are mutually identical. Furthermore, they are arranged in succession along the dispensing axis 2a.
• the outlines 4 are substantially formed along the dispensing axis 2a by the inner surface 3 and determine the overall shape of the cavity.
• the outline 4 is determined on a sectional plane 2c.
• the section plane 2c is preferably normal to the dispensing axis 2a. Therefore, the section plane 2c is substantially a virtual plane which, by cutting the acceleration conduit 2 normally to the dispensing axis 2a, defines on itself the outline 4 formed by the inner surface 3.
• the outline 4 also defines a first extension area.
• the extension area is the portion of two-dimensional space contained within the outline 4.
• the outline 4 is preferably inscribable in a circle.
• the circle is also determined on the section plane 2c.
• the circle is trivially a virtual geometric element within which the outline 4 is geometrically inscribable.
• the circle in addition, itself defines a second extension area on the section plane 2c.
• the outline 4 does not have a shape corresponding to the circle.
• the first extension area is less than 90% of the second extension area. Even more in detail, preferably, the first extension area is less than 60% of the second extension area.
• the outline 4 can be made according to different embodiments.
• the outline 4 may be a convex figure.
• a convex figure is a figure in which any segment joining any two points of it is entirely contained in the figure itself.
• the outline 4 if it is convex, it preferably defines a first dimension 4a and a second dimension 4b.
• the first dimension 4a is substantially the maximum dimension that the outline 4 determines in one direction.
• the second dimension 4b is also the maximum dimension in a direction perpendicular to the first dimension 4a.
• the second dimension 4b is less than 90% of the first dimension 4a. Even more in detail, the second dimension 4b may be less than 60% of the first dimension 4a.
• a convex outline 4 may have a nearly equilateral triangular shape, as shown in Fig. 6e , or almost rectangular, possibly even slightly rounded on the sides, as shown in Fig. 6d .
• the first dimension 4a may be provided by the height
• the second dimension 4b may be provided by the side intercepted by the height.
• the dimensions 4a, 4b may correspond to the respective sides.
• the outline 4 may instead be concave.
• the concavity of a figure is manifested when there is at least one segment that joins a pair of points of the figure does not belong entirely to the figure itself.
• the outline 4 is concave, it preferably includes at least one convex portion 40.
• the convex portion 40 is a part of a concave outline 4 that can be identified within the outline 4, in such a way as to be delimited at least in part, and which has the characteristic of convexity.
• the convex portion 40 can, similarly to the convex outline 4, define a third dimension 40a and a fourth dimension 40b.
• the third dimension 40a is substantially the maximum dimension that the convex portion 40 determines in one direction.
• the fourth dimension 40b is also the maximum dimension in a direction perpendicular to the third dimension 40a.
• the fourth dimension 40b is less than 90% of the third dimension 40a. Even more in detail, the fourth dimension 40b may be less than 60% of the third dimension 40a.
• a convex portion 4 of an outline 4 may have an almost triangular shape, as shown for example in Fig. 6h , or almost rectangular as shown in Figs. 6g and 6j , possibly with a bevelled side as in Fig. 6a , or even trapezoidal, as shown in Figs. 6b-6c .
• the first dimension 4a may be provided by the height
• the second dimension 4b may be provided by the base side on which the height lies.
• the dimensions 4a, 4b may correspond to the respective sides.
• a concave outline 4 may be formed by two or more mutually crossed convex portions 40.
• the concave outline 4 may define a cross/star shape having three to five tips (e.g. three as in Figs. 6a and 6c , or four as in Figs. 6f and 6i , or even five as in Figs. 6b and 6j ).
• the acceleration conduit 2 may also comprise an outer surface 5.
• the outer surface 5 is also closed. Furthermore, the outer surface 5 develops around the inner surface 3. Then, the outer surface 5 wraps around the inner surface 3.
• the outer surface 5, which faces the outside of the acceleration conduit 2 and therefore not in contact with the cavity, is connected to the inner surface 3 via a wall 6.
• the wall 6 is therefore surrounded by the surfaces 3, 5 and, therefore, the surfaces define opposite faces of the wall 6 with respect to the same wall 6.
• the outer surface 6 may thus be cylindrical, as shown in Figs. 7a-7j , 9a-9d and 10a-10d , or the outer surface 5 may alternatively be outlined as the inner surface 3. In this way, the surfaces 3, 5 determine a constant thickness for the wall 6, as shown for example in Figs. 5 and 8a-8d .
• acceleration conduit 2 can be used with other acceleration conduits 2 to form a group of acceleration conduits 2, for example also a tube pack for use in a plant.
• the spinneret 1 may comprise a plurality of acceleration conduits 2 all defining a same outline 4, as in Figs. 9a-9d .
• the chain 1 may comprise a plurality of said acceleration conduits 2 defining respective mutually different outlines 4, as in Figs. 8a-8d and 10b-10d .
• the spinneret 1 may comprise a plurality of acceleration conduits 2 each defining a circular outline, i.e. having a conventional outline according to the known art, as in Figs. 8c and 8a .
• the spinneret 1 may also comprise a plurality of acceleration conduits 2 each defining a circular outline, but different diameters.
• the invention also comprises a multi-row coaxial spundbond and/or melt-blown plant comprising a spinneret 1 as just described according to the different possible embodiments.
• the operation of the spinneret 1 for multi-row coaxial spunbond and/or melt-blown type plant described above in structural terms is substantially similar to the operation of any spinneret of the prior art, in the sense that it allows polymer fluid to be conveyed along the dispensing axes 2a of each acceleration conduit 2.
• the spinneret 1 for multi-row coaxial spunbond and/or melt-blown type plant according to the invention achieves important advantages.
• the multi-row coaxial spunbond and/or melt-blown type plant polymer filament chain allows to make a membrane, or layer, of sturdy non-woven fabric in different directions, in particular perpendicular to each other.
• the spinneret 1 for multi-row coaxial spunbond and/or melt-blown type plant also allows to create robust diapers given by coupling the different layers formed by the plant, in which in particular the weaker layer is subject to less breakage and is therefore more resistant and durable.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)

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Citations (3)

• 2025
  • 2025-03-14 EP EP25163825.0A patent/EP4621112A1/fr active Pending
  • 2025-03-14 JP JP2025041484A patent/JP2025143232A/ja active Pending
  • 2025-03-17 US US19/081,795 patent/US20250290231A1/en active Pending
  • 2025-03-17 CN CN202510313274.4A patent/CN120666454A/zh active Pending

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