Classifications

• • 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
• • 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
  • D01D5/098—Melt spinning methods with simultaneous stretching
• • 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
  • D01D5/098—Melt spinning methods with simultaneous stretching
  • D01D5/0985—Melt spinning methods with simultaneous stretching by means of a flowing gas (e.g. melt-blowing)
• • 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
  • D01D5/12—Stretch-spinning methods
  • D01D5/14—Stretch-spinning methods with flowing liquid or gaseous stretching media, e.g. solution-blowing
• • 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
  • D01D5/12—Stretch-spinning methods
  • D01D5/16—Stretch-spinning methods using rollers, or like mechanical devices, e.g. snubbing pins
• • 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
  • D04H3/10—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 yarns or filaments made mechanically
  • D04H3/105—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 yarns or filaments made mechanically by needling
• • 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
  • D04H3/14—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 yarns or filaments produced by welding

Definitions

• the present invention relates to an apparatus and process for the production of a nonwoven fabric which is used as reinforcement, typically in the construction field, for example as reinforcement in railways, airports, roads, highways and tunnels, armored concrete columns, or as reinforcement in earthquake-resistant structures, as reinforcement in agricultural areas or forests, as reinforcement in thermally insulating building structures, etc.
• nonwoven fabrics in civil engineering, to build infrastructures such as roads, bridges, railways, dam support works and hydrogeological retaining structures, is well known. These fabrics allow the element in/on which they are placed to be reinforced, for example by distributing loads evenly within the structure.
• nonwoven fabrics produced according to the known art have some limitations in terms of characteristics, such as mechanical characteristics.
• object of the present invention is to make a nonwoven fabric which can be effectively used as a reinforcement fabric in the field of civil engineering.
• an apparatus for the production of a nonwoven fabric comprises: a spinneret for extruding a plurality of filaments; at least one first cooling device arranged below the spinneret; a first aerodynamic drawing device downstream of the cooling device, to draw the filaments; a mechanical drawing device downstream of the first aerodynamic drawing device; a second aerodynamic drawing device downstream of the mechanical drawing device; a mechanical distributor arranged downstream of the second aerodynamic drawing device to divert the path of the filaments; a filament collecting device arranged below the mechanical distributor, wherein the collecting device comprises a collection surface to collect the filaments and form a nonwoven fabric; a suction element to suction gases below the filament collection surface.
• the present invention thus introduces drawing carried out in three different steps, by means of two aerodynamic devices (i.e. pneumatic, which draw the filaments by means of air flows), and a mechanical device interposed between the two aerodynamic drawing devices.
• two aerodynamic devices i.e. pneumatic, which draw the filaments by means of air flows
• a mechanical device interposed between the two aerodynamic drawing devices.
• Filament drawing is therefore progressive and allows high tenacity filaments to be formed.
• the mechanical drawing device comprises rollers.
• the rollers are typically rotatable at progressively increasing speeds in order to draw the filaments.
• the rollers comprise primary rollers and secondary rollers, wherein the secondary rollers are movable relative to the primary rollers.
• Such mobility allows the path of the filaments to be varied, or at any rate allows an easier initial step of spinning, in which the secondary rollers can be arranged so that they do not intercept the path of the filaments, so that the filaments can more easily pass between the rollers and then be arranged in a drawing position, in which the rollers intercept the filaments.
• the rollers are heatable preferably to a temperature between 60°C and 150° C, in order to adjust the temperature of an element against which the filaments come into contact, thereby preventing, for example, thermal shocks, or otherwise assisting the drawing by means of temporary heating.
• the apparatus comprises at least one needle-felting device (needle loom) and/or a calender downstream of the filament collection surface. Thanks to this, the newly deposited nonwoven fabric can be consolidated.
• the apparatus comprises a thermal treatment device and/or a water-jet device which is arranged downstream of the collecting device, preferably downstream of the needle-felting device and/or calender, and which is configured so as to set the nonwoven fabric, i.e., to bond together the filaments of the nonwoven fabric.
• An aspect of the present invention also relates to a process for the production of a nonwoven fabric, comprising the steps of: a) extruding a plurality of filaments by means of a spinneret; b) cooling the filaments by means of at least one first cooling device arranged below the spinneret; c) drawing the filaments by means of a first aerodynamic drawing device; d) drawing the filaments by means of a mechanical drawing device arranged downstream of the first aerodynamic drawing device; e) drawing the filaments by means of a second aerodynamic drawing device arranged downstream of the mechanical drawing device; f) operating a mechanical distributor arranged below the second aerodynamic drawing device so as to divert the path of at least part of the filaments; g) depositing the filaments on a collecting device to form a nonwoven fabric.
• the filaments are filled, that is, they comprise one or more filler materials.
• the process comprises the step of consolidating the nonwoven fabric by a needle-felting device and/or by a calender.
• the process comprises the step of thermally setting the nonwoven fabric, preferably following the step of consolidating the nonwoven fabric.
• the spinneret is formed, in a known way, to extrude the filaments 3, which can be mono-component or bi-component filaments.
• the spinneret or otherwise the material supplied to it, can be configured to provide a filler to the filaments, for example a metal filler.
• Preferred fillers are calcium carbonate or titanium oxide.
• the extruded filaments can be bi-component, preferably in side-by-side or core-sheath configuration with, for example, round or trilobate section.
• the filament is preferably made of SBS material, or styrene-butadiene-styrene.
• the cooling device 4 is typically configured to direct against the filaments 3 a cooled, or otherwise room-temperature, gas (typically air).
• the apparatus 1 also comprises three drawing devices 5, 6, 7 arranged in series.
• the apparatus comprises a first aerodynamic drawing device 5.
• the apparatus further comprises a mechanical drawing device 6 arranged downstream of the first aerodynamic drawing device 5, typically below the latter.
• the rollers 61 - 65 are rotatable about their own axis of rotation A61 - A65, preferably at a speed between 400 meters/minute and 2000 meters/minute.
• At least part of the rollers is configured so that it can be heated, for example by means of an oleodynamic circuit.
• the heated rollers are configured to have a temperature preferably between 60°C and 150°C when in use.
• all the heated rollers are upstream of all the unheated rollers.
• all the rollers are heated except for the roller immediately upstream of the crimping device 6 (i.e., except for the roller furthest downstream in the path of the filaments 3).
• This last roller i.e., the roller 65 in the embodiment shown in the figures, is configured to have a temperature between 20°C and 50°C. This can be done by means of a dedicated device adapted to cause the roller to reach the desired temperature or, more preferably, such a roller has no heating/cooling means, so that it remains basically at room temperature.
• the primary rollers 61, 63, 65 and the secondary rollers 62, 64 are constrained to the frame of the apparatus (not shown herein in detail) so as to allow a relative movement between the primary and secondary rollers so that to alternately engage and disengage the filaments 3.
• the secondary rollers 62, 64 and the primary rollers 61, 63, 65 are preferably arranged alternately with each other so that, in use, the filaments 3 alternately meet a primary roller and a secondary roller.
• the secondary rollers 62, 64 are typically translatable alternately along a curve or, more preferably, a straight line. According to an embodiment, considering a condition of use, the secondary rollers 62, 64 are movable horizontally, as schematically shown for example in Figure 3 where the initial position of the rollers is shown schematically by dashed lines. It should be noted that Figure 3 is only a schematic illustration, so that proportions and distances traveled are not to scale.
• the apparatus 1 comprises an additional aerodynamic drawing device 7 downstream of the mechanical drawing device 6.
• the second aerodynamic drawing device 7 is configured to draw the filaments 3 by one or more flows of gas, typically air.
• the air pressure in the second aerodynamic drawing device is preferably between 0.2 and 2 bars.
• the apparatus 1 further comprises a mechanical distributor 8 arranged below said second cooling device 7 in order to divert the path of said plurality of filaments, so as to direct them towards a collecting device 9.
• the mechanical distributor 8 allows the filaments 3 to be separated and distributed over the deposition surface 91 of the collecting device 9, in order to form the voluminous nonwoven fabric 150.
• the mechanical distributor 8 comprises a movable shelf 101 on which the filaments 3 leaving the second aerodynamic drawing device 7 are laid.
• the movement of the movable shelf diverts the fall path of the filaments 3, which are deposited on a collecting device 9 comprising a surface 91 on which a first nonwoven fabric 150 is formed.
• the mechanical distributor comprises a fixed shelf 102 and a swinging rod 30.
• the filaments leaving the cooling device 7 are laid on the fixed shelf 102 by deflecting the fall path in the direction of the swinging rod 30, which causes the filaments 3 to swing/vibrate before being deposited on a collection surface 91 of the collecting device 9.
• a further embodiment (not shown in the figures) provides a mechanical distributor comprising alternately moving blades which allow the crimped filaments 3 to be separated and distributed on the deposition surface 91, in order to form the first voluminous nonwoven fabric 150.
• the mechanical distributor 8 typically comprises a movable element 101, 30 adapted to deflect the filaments 3 in a time-varying way.
• a movable element moves at a movement frequency of between 100 and 1000 movements (oscillation)/minute.
• the collecting device 9 can take various forms and typically comprises a movable belt. Furthermore, the apparatus typically comprises a suction element 92 to suction gases below the filament collection surface 91, in order to promote the formation of a first nonwoven fabric 150.
• the apparatus 1 further comprises at least one needle-felting device 13 downstream of the collecting device 9, that is, downstream of the region where the filaments 3 meet the collecting device 9.
• the needle-felting device 13 allows the filaments 3 of the nonwoven fabric 150 to be bonded, thereby allowing the first nonwoven fabric 150 to be consolidated.
• the apparatus 1 may comprise a calender 11, possibly heated, to consolidate the nonwoven fabric 150.
• the calender 11 is typically downstream of the needle-felting device 13.
• the apparatus comprises a thermal treatment device 12, which is typically adapted to heat the nonwoven fabric 150 and which is arranged downstream of the collecting device and of either the needle-felting device 13 or calender 11, if any.
• the thermal treatment device can heat the nonwoven fabric 150 according to various methodologies, typically by convection and/or radiation, preferably by a flow of air heated between 80°C and 150°C.
• the thermal treatment device 12 allows the nonwoven fabric to be thermally set.
• the nonwoven fabric can also be hydro-treated, typically with a water-jet device, for further consolidation.
• the nonwoven fabric 150 is typically collected by means of special devices, typically is wound into bobbin form.
• a plurality of filaments 3 are extruded from the spinneret 2.
• the extruded filaments are cooled by means of the cooling device 4 arranged below the spinneret 2.
• the filaments 3 are drawn by means of the three drawing devices 5, 6, 7, which are arranged in series downstream of the cooling device 4.
• the aerodynamic drawing devices 5, 7 draw the filaments by one or more gas (air) flows
• the mechanical drawing device 6 preferably comprises primary rollers 61, 63, 65 and secondary rollers 62, 64 in which the secondary rollers are movable relative to the primary rollers.
• the secondary rollers are typically arranged in the disengaged condition to allow the filaments 3 to pass between the rollers 61 - 65.
• the secondary rollers are brought to the drawing position, so as to engage the filaments and cause them to be drawn.
• the filaments passing around the rollers alternately meet the first and second secondary rollers.
• the filaments are laid alternately on a surface portion of a primary roller and then are laid on a surface portion of a secondary roller.
• the filaments 3 exhibit a basically S-shaped pattern in the transition from a primary roller to a secondary roller.
• At least part of the rollers can be heated, preferably between 60° C and 150° C, so as to affect the temperature of the filaments 3.
• the last roller to meet the filaments is preferably unheated, at a temperature between 15°C and 25°C.
• the filaments 3 are diverted and scattered in their fall path by the mechanical distributor 8 in order to increase the surface where the filaments 3 are deposited on the deposition surface 91 of the collecting device to form the nonwoven fabric 150.
• the suction element 92 suctions air so as not to disperse the filaments deposited on the deposition surface 91 and ensure the proper formation of the nonwoven fabric 150.
• the nonwoven fabric 150 can undergo different treatments.
• the nonwoven fabric 150 can be consolidated by a needle-felting device 13 and/or a calender 11.
• the first nonwoven fabric 150 can also be heated to set the filaments 3, and possibly hydrotreated to perform further consolidation or bonding.
• the fabric can be hydrotreated, typically by a water-jet device.
• water-jet treatment can be used instead of thermal treatment to set and bond the filaments together.
• the nonwoven fabric 150 is typically collected, typically wound, according to known methods.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Nonwoven Fabrics (AREA)

Priority Applications (1)

Applications Claiming Priority (1)

Publications (1)

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Family Applications (1)

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Citations (4)

• 2024
  • 2024-01-26 EP EP24154256.2A patent/EP4592440A1/fr active Pending

Patent Citations (4)

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