ES2387729T3 - Apparatus, process and set of nozzles for extruding cellulose fibers - Google Patents

Abstract

Apparatus (26) for extrusion of cellulose fibers (12) comprising: a) a first element (42) having multiple nozzles (44) arranged in rows, each of said nozzles (44) having an inner diameter through which an aqueous solution (20) consisting of cellulose (16) and a solvent (18) can be extruded, and formed through said first element (42) at least one passage (48) through which a compressed gas (34) can be routed ); b) a second element (52) fixed to said first element (42), said second element (52) having multiple passages (54) formed therethrough which are connected to said passage (48) which is at least one and is formed in said first element (42), and formed through said second element (52) multiple openings (58) through which each of said multiple nozzles (44) can pass; and c) a third element (60) fixed to said second element (52), said third element (60) being formed through multiple first openings (62), each of said multiple first openings (62) being sized to allow a of said multiple nozzles (44) pass through it, each of said multiple first openings (62) concentrically aligned around each of said multiple nozzles (44), each of said multiple first openings (62) being connected to said corridors (54) for compressed gas formed in said second element (52) and each of said multiple first openings being capable of emitting compressed gas (34) therethrough such that said compressed gas (34) partially surrounds at least said solution aqueous (20) extruded from each of said multiple nozzles (44), and said third element (60) also having multiple second openings (64) formed therethrough connected to said corridors (54) for compressed gas formed in said second element (52), each of said multiple second openings (64) positioned next to one of said multiple nozzles (44), and each of said multiple second openings (64 ) a diameter through which said compressed gas (34) can be emitted, characterized in that multiple needles (66) are arranged next to said multiple nozzles (44), each of said multiple needles (66) passing through one of said multiple aisles (54) and each of said multiple second openings (64) being greater than each of said multiple needles (66).

Description

Apparatus, process and set of nozzles for extruding cellulose fibers

[0001] This invention relates to an apparatus, a process and a set of nozzles for extruding cellulose fibers.

[0002] There are currently several different methods for extruding an aqueous solution containing cellulose and a water-soluble solvent in order to obtain cellulose fibers. Each of these methods uses special equipment to heat the aqueous solution and extrude it through a matrix holder assembly. The matrix holder assembly may include several components for directing and distributing the aqueous solution and compressed gas through a plurality of nozzles so as to form a plurality of molten filaments. The aqueous solution is usually extruded in the downward direction, so that the compressed gas and gravity will cause the aqueous solution to thin so as to form a plurality of molten filaments. The molten filaments are then brought into contact with a liquid, which causes a greater part of the solvent to be solvated in the liquid solution and thus allows the molten filaments to coagulate in order to form solid cellulose fibers. These solid cellulose fibers are then collected on a moving surface, such as a porous conveyor belt or a porous rotating drum, and form a nonwoven fabric.

[0003] So far no one has been able to design and build an apparatus or process that allows extrusion and forming cellulose fibers having a diameter of less than about 15 microns at a rate that makes a process of this economically feasible kind. In addition, no one has been able to design and build a row that extrudes 20 or more molten filaments per linear centimeter at a flow rate of more than 1.0 grams / hole / minute and with a production speed of up to approximately 750 meters per minute. In addition, no one has been able to extrude an aqueous solution containing cellulose and a backpressure solvent of more than 20 bars without damaging the row. In addition, no one has been able to extrude and form very fine cellulose fibers that have a diameter of less than 5 microns at a rate of more than 0.5 grams / hole / minute and with a speed of production of up to approximately 750 meters per minute. Finally, no one has been able to form a nonwoven fabric that is made of such cellulose fibers and has a basis weight of less than about 1 gram per square meter with a production speed of more than about 30 meters. per minute.

[0004] International application WO 2005/106085 A1 discloses a method and an apparatus in which a cellulose solution is extruded through a first plurality of uniformly spaced nozzles and when exiting the nozzles is accelerated and thinned by jets gaseous at high speed to form fine cellulosic fibers. A coagulant solution is forced to pass through a second plurality of nozzles that are uniformly spaced from each other and uniformly spaced from those of the first plurality of nozzles and are generally parallel thereto and form high velocity jets, such that the coagulant solution affects the fine cellulosic fibers by additionally thinning them and causing them to clot.

[0005] An apparatus according to claim 1, a process according to claim 5 and a use according to claim 11 have now been invented which will allow extruding and forming cellulose fibers each having a diameter of less than about 15 microns at the rate of a flow rate of more than about 0.1 grams / hole / minute. The apparatus, the process and the set of nozzles are also capable of forming very fine cellulose fibers each having a diameter of less than about 5 microns at a rate of more than about 0.5 grams / hole / minute. In addition, the apparatus, the process and the set of nozzles produce cellulose fibers that have unique characteristics and can be collected to form a non-woven fabric.

[0006] Briefly, this invention relates to an apparatus, a process and a use of a set of nozzles for extruding cellulose fibers. The apparatus includes a first element fixed to a spinning paste supply mechanism. The first element has a plurality of nozzles arranged in rows. Each of the nozzles has an inner diameter through which an aqueous solution of cellulose and a solvent can be extruded. Each of the nozzles also has formed therein at least one other passage through which a compressed gas can be routed. The apparatus also includes a second element fixed to the first element. The second element has multiple passages formed therethrough which remain connected to the passage formed in the first element, and multiple openings formed therein through which the multiple nozzles can pass. The apparatus also includes a third element fixed to the second element. The third element has multiple first openings formed therethrough. Each of the first multiple openings is sized to allow one of the multiple nozzles to pass through. Each of the first openings is connected to the corridors for compressed gas formed in the second element. Each of the first openings is capable of emitting compressed gas therethrough, such that the compressed gas surrounds at least partially the aqueous solution that is extruded from each of the nozzles. The third element also has multiple second openings formed therethrough which remain connected to the compressed gas passageways formed in the second element. Each of the second openings is positioned next to one of the nozzles, in each of the rows, and each of the second openings has an opening through which the compressed gas can be emitted.

[0007] The process includes the steps of forming an aqueous solution of cellulose and a solvent. This aqueous solution is directed through a row that has multiple rows of nozzles and second openings. The nozzles are different from the second openings. At least one of the nozzles in one of the rows is arranged to the triplet with respect to at least one of the nozzles of an adjacent row, each of the nozzles having a first opening aligned next to it. The aqueous solution is extruded through each of the nozzles to form multiple molten filaments. At least a part of each of the molten filaments is wrapped in a compressed gas emitted through the first adjacent opening. The molten filaments are then thinned to a circular cross-sectional configuration having a diameter of less than about 5 microns. Each of the molten filaments is brought into contact with a liquid that chemically reacts with the solvent to remove some of the solvent, whereby each of the molten filaments is transformed into a continuous solid fiber. The solid continuous fibers are then collected on a moving surface so as to form a cellulose nonwoven fabric.

[0008] Each nozzle has a longitudinal central axis and includes a hollow cylindrical tube having a predetermined cross section. An aqueous solution of cellulose and a solvent is extruded through each of the hollow cylindrical tubes so as to form multiple individual molten filaments. Each of the hollow cylindrical tubes is surrounded by a first opening having a singularly shaped cross section with a diameter. The diameter of each of the first openings is larger than the diameter of each of the hollow cylindrical tubes. Each of the first openings is capable of emitting a compressed gas surrounding one of the extruded molten filaments. At least three second openings are spaced outwards from each of the first openings. Each of the second openings is capable of emitting a stream of compressed gas that is essentially parallel to the longitudinal central axis of each of the nozzles and serves to wrap each of the extruded molten filaments.

[0009] The general object of this invention is to provide an apparatus that is capable of extruding cellulose fibers having a diameter of less than about 15 microns at a rate of more than 0.1 grams / hole / minute and with a production speed of up to approximately 750 meters per minute. A more specific object of this invention is to provide an apparatus that is capable of extruding very fine cellulose fibers having a diameter of less than about 5 microns at a rate of more than 0.5 grams / hole / minute and with a production speed of up to approximately 750 meters per minute.

[0010] Another object of this invention is to provide an apparatus for extruding cellulose fibers having a circular configuration in cross section and a diameter of approximately 5 microns or less.

[0011] Another object of this invention is to provide an apparatus for extruding very fine cellulose fibers having a diameter of less than about 3 microns.

[0012] Yet another object of this invention is to provide an apparatus that is for extruding cellulose fibers and includes a set of nozzles that are capable of extruding an aqueous cellulose solution and a water-soluble solvent together with compressed gas so that a thinned molten filament does not adhere to an adjacent molten filament.

[0013] Even further, an object of this invention is to provide an apparatus for extruding cellulose fibers economically and efficiently.

[0014] Another object of this invention is to provide a process for forming a cellulose nonwoven fabric. A more specific object of this invention is to provide a non-woven cellulose fabric produced by means of such a process.

[0015] Yet another object of this invention is to provide a process for forming a fabric made of multiple cellulose fibers each having a diameter of less than about 15 microns.

[0016] Yet another object of this invention is to provide a use of a set of nozzles to extrude multiple cellulose fibers at high speeds. A more specific object of this invention is to provide a use of a set of nozzles to extrude multiple cellulose fibers having a diameter of less than about 15 microns at a rate of more than 0.1 grams / hole / minute and with a production speed of up to approximately 750 meters per minute.

[0017] Even further, an object of this invention is to provide a use of a set of nozzles for extruding multiple cellulose fibers each having a uniquely shaped cross-sectional configuration and a diameter of approximately 5 microns or less.

[0018] According to one embodiment, an apparatus for extruding cellulose fibers comprises: a) a first element having multiple nozzles arranged in rows, each of said nozzles having an inner diameter through which an aqueous solution comprising of cellulose and a solvent, and having at least one passage formed therein through which a compressed gas can be routed; b) a second element fixed to said first element, said second element having multiple passages formed therethrough which remain connected to at least one passage formed in said first element, and multiple openings formed therein through which said passages can pass multiple nozzles; and c) a third element fixed to said second element, said third element having multiple first openings formed therethrough, each of said multiple first openings being sized to allow one of said multiple nozzles to pass therethrough, each of said being multiple first openings concentrically aligned around each of said multiple nozzles, each of said multiple first openings being connected to said compressed gas passageways formed in said second element and each of them being capable of emitting compressed gas therethrough such that said compressed gas at least partially surrounds said extruded aqueous solution from each of said multiple nozzles, and said third element having through it also multiple second openings that are connected to said compressed gas passageways formed in said second element, each of said mu being The multiple second openings positioned next to one of said multiple nozzles in each of said rows, and each of said multiple second openings has a diameter through which said compressed gas can be emitted.

[0019] According to one embodiment, the apparatus of one of the preceding claims is capable of forming cellulose fibers having a diameter of less than about 15 microns at a rate of more than 0.1 grams / hole / minute, and It is in particular capable of forming cellulose fibers having a diameter of less than about 5 microns at a rate of more than 0.5 grams / hole / minute.

[0020] According to an embodiment of the apparatus of one of the preceding claims, said third element has an even number of rows of nozzles, at least one of said nozzles being of a row displaced with respect to one of said nozzles of an adjacent row.

[0021] According to an embodiment of the apparatus of one of the previous embodiments, each of said multiple hollow cylindrical tubes has an inside diameter ranging from about 0.125 millimeters to about 1.25 millimeters.

[0022] According to an embodiment of the apparatus of one of the previous embodiments, each of said multiple nozzles is made of stainless steel.

[0023] According to an embodiment of the apparatus of one of the previous embodiments, each of said multiple second openings has a venturi formed therein.

[0024] According to an embodiment of the apparatus of one of the previous embodiments, said third element has an odd number of rows, wherein at least two of said nozzles of a row are offset with respect to two of said nozzles of an adjacent row.

[0025] According to an embodiment of the apparatus of one of the previous embodiments, each of said second openings contains a needle therein.

[0026] According to an embodiment of the apparatus of one of the above embodiments, an apparatus for extruding cellulose fibers comprises: a) a filter block fixed to a spinning paste supply mechanism, said filter block having a filter formed therein first passage through which an aqueous solution consisting of cellulose and a solvent can be routed, and formed therein a second passage through which a compressed gas can be routed; b) a row fixed to said filter block, said row having multiple nozzles arranged in rows, each of said nozzles having a longitudinal central axis with an inner diameter through which said aqueous solution can be extruded, and said row having formed through it at least one passage that is connected to said second passage; c) a gas distribution plate fixed to said row, said gas distribution plate having multiple passages formed therethrough which are connected to said passage which is at least one and is formed in said row, and formed therein multiple openings through which said multiple nozzles can pass; d) an outer plate fixed to said gas distribution plate, said outer plate having multiple first openings formed therethrough, each of said first multiple openings being sized to allow one of said multiple nozzles to pass through it, each being one of said multiple first openings concentrically aligned around each of said multiple nozzles, each of said multiple first openings being connected to said compressed gas passageways that are formed in said gas distribution plate and are each capable of emitting compressed gas therethrough such that said compressed gas at least partially surrounds said extruded aqueous solution from each of said multiple nozzles, and said outer plate also having multiple second openings therethrough which are connected to said gas passageways tablet formed in said gas distribution plate, each of said multiple second openings being positioned next to one of said multiple nozzles in each of said rows, at least one of said nozzles being displaced with respect to a nozzle of an adjacent row, and each of said multiple second opening having a diameter through which said compressed gas can be emitted.

[0027] According to an embodiment of the apparatus of one of the previous embodiments, said outer plate has at least three rows of nozzles, each row containing an equal number or an unequal number of said first and second openings.

[0028] According to an embodiment of the apparatus of one of the preceding claims, said outer plate has at least 20 openings per linear centimeter.

[0029] According to one embodiment, in particular of the apparatus of one of the above embodiments, an apparatus comprises: a) a spinning paste supply mechanism having a first conduit formed therein through which an aqueous solution can be routed which it consists of cellulose and a solvent, and formed therein a second conduit through which a compressed gas can be routed; b) a filter block fixed to said spinning paste supply mechanism, said filter block having at least two independent passages formed therethrough, each of said passages being in connection with one of the first and second ducts; c) a row fixed to said filter block, said row having multiple nozzles arranged in rows, each of said nozzles being an elongated hollow tube having a longitudinal central axis with a cross section having an opening through which said aqueous solution can be extruded, and having at least one passage formed therein connected to said passage for compressed gas formed in said filter block; d) a gas distribution plate fixed to said row, said gas distribution plate having multiple aisles formed therein which are connected to said passage formed in said row to route said compressed gas therethrough, and formed therein through multiple openings each of which is sized to allow one of said multiple nozzles to pass through; and e) an outer plate fixed to said gas distribution plate, said outer plate having multiple first openings formed therethrough, each of said first multiple openings being sized to allow one of said multiple nozzles to pass through it, being each of said multiple first openings concentrically aligned around each of said multiple nozzles, each of said multiple first openings connected to said compressed gas passageways that are formed in said gas distribution plate and are each capable of emitting compressed gas therethrough such that said compressed gas at least partially surrounds said extruded aqueous solution from each of said multiple nozzles; and said outer plate also having multiple second openings therethrough which are connected to said compressed gas passageways formed in said gas distribution plate, each of said multiple second openings positioned therein a central rod having a section transverse through which said compressed gas can be emitted, and at least one of said nozzles of one of said rows arranged at the triplet with respect to at least one of said nozzles of an adjacent row.

[0030] According to an embodiment of the apparatus of one of the above embodiments, the compressed gas can pass through said assembly at a speed of at least 45 meters per second and each of said first multiple openings includes at least two sickle slits.

[0031] According to an embodiment of the apparatus of one of the previous embodiments, said outer plate has at least 60 openings per linear centimeter.

[0032] According to one embodiment, in particular of the apparatus of one of the above embodiments, an apparatus comprises a set of nozzles for extruding multiple cellulose fibers, comprising: a) multiple nozzles each having a longitudinal central axis and including each a tube with a cross-section having a diameter through which an aqueous solution consisting of cellulose and a solvent can be extruded to be thus transformed into a molten filament, and a first opening surrounding each of said tubes and it has a cross section with a diameter, said diameter of said first opening being greater than said diameter of said tube, and each of said first openings being capable of emitting a compressed gas surrounding one of said extruded molten filaments; and b) at least three second openings that are each spaced outwardly from each of said first openings, each of said second openings being capable of emitting a stream of compressed gas that is essentially parallel to said longitudinal central axis of said nozzle, and each of said compressed gas streams serving to wrap one of said extruded molten filaments.

[0033] According to an embodiment of the apparatus of one of the previous embodiments, said compressed gas that is emitted from each of said first openings thins and accelerates each of said extruded molten filaments from each of said tubes in order to transform it into a continuous fiber having a diameter of less than about 15 microns.

[0034] According to an embodiment of the apparatus of one of the previous embodiments, each and every one of said first and second openings are aligned parallel to each other.

[0035] According to an embodiment of the apparatus of one of the previous embodiments, each of said second openings is spaced at a distance between about 1 millimeter and about 4 millimeters of said longitudinal central axis of said nozzle, and each of said second openings are spaced at a distance between about 1 millimeter and about 2 millimeters of said longitudinal central axis of one of said nozzles.

[0036] According to an embodiment of the apparatus of one of the previous embodiments, each of said tubes extends downwardly beyond said first openings exceeding them by at least 1 millimeter, in particular at least 3 millimeters, and in particular in At least 5 millimeters.

[0037] According to one embodiment, in particular of the apparatus of one of the above embodiments, an apparatus comprises a set of nozzles comprising: a) multiple nozzles each having a longitudinal central axis and each including a hollow cylindrical tube with a cross section that has a constant diameter through which an aqueous solution consisting of cellulose and a water-soluble solvent can be extruded to be thus transformed into a molten filament, and a first opening that surrounds each of said hollow cylindrical tubes and has a cross section with a constant diameter, said diameter of each of said first openings being greater than said diameter of each of said hollow cylindrical tubes, and each of said first openings being capable of emitting a compressed gas that surrounds at least partially to one of said extruded molten filaments; and b) a plurality of second openings that are each spaced outwardly from each of said first openings, each of said second openings being capable of emitting a stream of compressed gas that is essentially parallel to said longitudinal central axis of each one of said nozzles, and each of said compressed gas streams serving to wrap one of said extruded molten filaments.

[0038] According to an embodiment of the apparatus of one of the previous embodiments, there are at least three second openings for each first opening and each of said second openings is equally distanced from a second adjacent opening.

[0039] According to an embodiment of the apparatus of one of the previous embodiments, there are eight second openings for each first opening and said second individual openings are spaced apart from each other at a distance of approximately 45 degrees.

[0040] According to one embodiment, in particular of the apparatus of one of the previous embodiments, an apparatus comprises a set of nozzles comprising: a) multiple nozzles arranged in rows, each of said nozzles having a longitudinal central axis and each including of said nozzles a hollow cylindrical tube that has a cross-section and has a constant diameter positioned therein, through which an aqueous solution consisting of cellulose and a water-soluble solvent can be extruded to be thus transformed into a molten filament, and a first opening that is concentrically aligned around one of said hollow cylindrical tubes and has a cross section with a constant diameter, said diameter of said first opening being greater than said diameter of each of said hollow cylindrical tubes, and said first being opening capable of emitting compressed gas therethrough which at least partially surrounds said cast extruded filament; b) multiple second openings arranged in said rows with said multiple nozzles, at least two of said second openings positioned next to one of said nozzles in each of said rows, each of said second openings positioned therein a needle and each of said second openings having a diameter through which a compressed gas can be emitted; and c) at least one of said nozzles of a row displaced with respect to one of said nozzles of an adjacent row.

[0041] According to an embodiment of the apparatus of one of the previous embodiments, each of said first openings includes at least two sickle slits that are distanced from said hollow cylindrical tube. According to an embodiment of the apparatus of one of the previous embodiments, each of said hollow cylindrical tubes is vertically spaced downwardly from each of said first openings by at least 3 millimeters.

[0042] According to an embodiment of the apparatus of one of the previous embodiments, each of said second openings has a side wall aligned perpendicularly to each of said second openings.

[0043] According to one embodiment, a process for forming a nonwoven cellulose fabric comprises the steps of: a) forming an aqueous solution of cellulose and a solvent; b) directing said aqueous solution through a first element having multiple rows of first and second openings, each of said first openings positioned therein a nozzle, and at least one of said nozzles being of a row disposed to the three ring with respect to at least one of said nozzles of an adjacent row; c) extruding said aqueous solution through each of said nozzles so as to form multiple molten filaments; d) wrapping at least a portion of each of said molten filaments in a compressed gas emitted through each of said first and second adjacently aligned openings; e) thinning said molten filaments so as to give them in cross-section a circular configuration having a diameter of less than about 15 microns; f) placing said molten filaments in contact with a liquid, said liquid being mixed with said solvent to remove some of said solvent, whereby each of said molten filaments is transformed into a continuous solid fiber; and g) collecting said continuous solid fibers on a moving surface so as to form a cellulose nonwoven fabric.

[0044] According to one embodiment, the process of one of the above embodiments comprises the step of heating said aqueous solution to a temperature between about 80 ° C and about 140 ° C and heating said compressed gas to a temperature of at least about 120 ° C.

[0045] According to one embodiment, the process of one of the above embodiments comprises the step of extruding said aqueous solution through each of said nozzles at a flow rate of more than 0.1 grams / hole / minute. According to one embodiment, the process of one of the above embodiments comprises the step of emitting said compressed gas through each of said first openings at a speed of at least 45 meters per second, each of said first openings including at least two slits. Sickle

[0046] According to one embodiment, the process of one of the previous embodiments comprises the step of emitting said compressed gas through each of said second openings at a speed of at least 45 meters per second.

[0047] According to an embodiment of the process of one of the above embodiments, said compressed gas is compressed air that is emitted from each of said first openings essentially parallel to said molten filament extruded through each of said nozzles, and said Compressed air accelerates and thins each of said molten filaments.

[0048] According to one embodiment, the process of one of the preceding claims comprises the step of putting each of said molten filaments in contact with a liquid, which causes said molten filaments to coagulate in order to transform into a continuous solid fiber. .

[0049] According to an embodiment of the process of one of the previous embodiments, said liquid is water, and each of said molten filaments is contacted with said water at a distance of at least about 3 centimeters from each of said nozzles.

[0050] According to one embodiment, the process of one of the above embodiments comprises the steps of: a) forming an aqueous cellulose solution and a solvent, said aqueous solution having a temperature of at least about 100 ° C; b) directing said aqueous solution through a first element having multiple rows of first and second openings, each of said first openings having a nozzle positioned therein, and at least one of said nozzles being of a row disposed to the three ring with respect to at least one of said nozzles of an adjacent row; c) extruding said aqueous solution through each of said nozzles at a back pressure of at least 10 bars in order to form multiple molten filaments; d) wrapping at least a portion of each of said molten filaments in a compressed gas emitted through each of said first and second adjacently aligned openings; e) thinning said molten filaments so as to give them in cross-section a circular configuration having a diameter of less than about 5 microns; f) placing said molten filaments in contact with a liquid, said liquid being mixed with said solvent to remove some of said solvent, whereby each of said molten filaments is transformed into a continuous solid fiber; and g) collecting said continuous solid fibers on a moving surface so as to form a cellulose nonwoven fabric.

[0051] According to an embodiment of the process of one of the previous embodiments, said compressed gas emitted from each of said second openings prevents individual individual molten filaments from physically coming into contact with each other.

[0052] According to one embodiment, the process of one of the above embodiments comprises the steps of extruding said aqueous solution downward from each of said nozzles parallel to a longitudinal central axis and placing each of said molten filaments in contact with water. introduced at an angle of between about 5 degrees and about 175 degrees, said water making each of said molten filaments coagulate in order to become a continuous solid fiber.

[0053] According to one embodiment, the process of one of the above embodiments comprises the step of heating said compressed gas to a temperature between about 120 ° C and about 160 ° C.

[0054] According to an embodiment of the process of one of the above embodiments, said moving surface is a rotating drum having a porous surface or a conveyor belt having a porous surface.

[0055] According to one embodiment, the process of one of the above embodiments comprises the step of initiating said process by performing the following steps: a) heating said aqueous solution to a predetermined temperature of more than 80 ° C; b) directing said heated aqueous solution to said first element and extruding said heated aqueous solution through each of said nozzles at a back pressure of at least 10 bars; c) route to said gas

compressed through each of said first and second openings at a speed of between approximately 1 meter per second and approximately 10 meters per second; d) heating said compressed gas to a temperature of about 100 ° C; and e) gradually increasing said speed of said compressed gas until said compressed gas reaches a speed of at least about 45 meters per second.

[0056] According to one embodiment, the process of one of the above embodiments comprises the step of stopping said process by performing the following steps: a) disconnecting said heat used to heat said compressed gas; b) gradually reduce said speed of said compressed gas to 0 meters per second; c) make said solution aqueous stop flowing through each of said nozzles; and d) allowing said aqueous solution to cool to room temperature.

[0057] Other objects and advantages of the present invention will be more obvious to those skilled in the art in sight of the following description and accompanying drawings: Fig. 1 is a schematic representation of a cellulose fiber formation process. Fig. 2 is a sectional view of a matrix holder assembly showing multiple first and second nozzles. Fig. 3 is a front view of a nozzle. Fig. 4 is a front view of a second nozzle. Fig. 5 is a partially exploded view of a part of the row body shown within the area identified with the letter A. Fig. 6 is an enlarged partial sectional view of a second nozzle having a constant inside diameter. Fig. 7 is an enlarged partial sectional view of a second nozzle having a venturi. Fig. 8 is a front view of an alternative design for the first opening. Fig. 9 is a front view of yet another embodiment for the first opening. Fig. 10 is a front view of an additional embodiment for the first opening. Fig. 11 is a front view for yet another embodiment for the first opening. Fig. 12 is a front view of yet another embodiment of the first opening. Fig. 13 is a plan view of a set of first and second nozzles formed in an outer plate. Fig. 14 is a plan view of an alternative set of first and second nozzles formed on a plate Exterior. Fig. 15 is a plan view of an assembly where each nozzle is surrounded by three of the second openings. Fig. 16 is a plan view of an assembly where each nozzle is surrounded by four of the second openings Fig. 17 is a plan view of an assembly where each nozzle is surrounded by six of the second openings. Fig. 18 is a plan view of an assembly where each nozzle is surrounded by eight of the second openings Fig. 19 is an enlarged sectional view of a nozzle showing a molten filament being extruded from the same. Fig. 20 is a plan view of a coagulated cellulose fiber.

[0058] Referring to Fig. 1, there is shown a process 10 of cellulose fiber formation 12 with which can be made from a nonwoven fabric 14. Process 10 includes the steps of combining and dissolving cellulose 16 and a solvent 18 to form an aqueous solution 20. The aqueous solution 20 is commonly referred to as a spinnable paste in the industry. The type of raw cellulosic material used may vary. Cellulose is a C6H10O5 carbohydrate complex which is composed of glucose units that form the main constituent of the cell wall in most of the plants. The cellulosic material can be bleached or unbleached wood pulp that can be made by of several procedures, of which the Kraft process, the prehydrolyzed Kraft and the sulphite process would be examples. Many other cellulosic materials can be used separately or in combination with wood pulp Starting, including, but not limited to, members of the group consisting of: cotton linters purified, plants, fats, etc. Cellulose 16 can be wood pulp of any of a series of commercially available soluble or non-soluble class pulps. Examples of some sources of pulp from Wood include the following: Sappi Saiccor sulphite pulp from the Weyerhaeuser Company, International Paper Company, and the pre-rolled kraft pulp of the International Paper Company. In addition, wood pulp can be a pulp of high hemicellulose content with a low degree of polymerization. The cellulosic material can be chopped or shredded to become a fine drunk to promote the formation of a solution aqueous 20 with solvent 18.

[0059] Solvent 18 is as desirable a water-soluble solvent. For example, solvent 18 may be an oxide of amine, and as desired a tertiary amine N-oxide containing a non-solvent for cellulose, such as water. They are indicated in U.S. Pat. 5,409,532, granted to Astegger et al., Representative examples of oxide solvents amine that are useful in the practice of this invention. The desired solvent is N-methylmorpholine N-oxide (NMMO). Other representative examples of solvents include members of the group consisting of dimethylsulfoxides (DMSO), dimethylacetamides (DMAC), dimethylformamides (DMF) and derivatives of caprolactam. Pulp it can be dissolved in an amine oxide solvent by any procedures recognized in the art such such as those set forth in U.S. Pat. 4,246,221, granted McCorsley, III; 5,330,567, granted to Zikei et al.,

and 5,534,113, granted to Quigley et al. Still other solvents that may be used in this invention include members of the group consisting of dilute caustic soda, phosphoric acid, a mixture of liquid ammonia / liquid ammonia thiocyanate, and others. Yet another way of making an aqueous cellulose solution is described in U.S. Pat. 6,306,334, granted to Luo et al.

[0060] The aqueous solution 20 is then heated in a heater 22 or by some other type of heating mechanism to a high predetermined temperature. The aqueous solution 20 can be heated to a temperature ranging from about 80 ° C to about 140 ° C. As desired, the aqueous solution 20 is heated to a temperature of at least 100 ° C. According to what is most desirable, the aqueous solution 20 is heated to a temperature of at least about 110 ° C. As most desirable, the aqueous solution 20 is heated to a temperature of at least about 120 ° C.

[0061] The aqueous solution 20 of cellulose 16 and solvent 18 can be made in a known manner, such as, for example, as taught in U.S. Pat. 4,246,221, granted to McCorsley, III, which by reference is incorporated herein and becomes part of it. In U.S. Patent 4,246,221, the cellulose is soaked in a non-solvent mixture of approximately 40% NMMO and 60% water. The ratio of cellulose to wet NMMO is approximately 1: 5.1 by weight. The mixture is made in a double arm sigma vane mixer for approximately 1.3 hours under vacuum at approximately 120 ° C until sufficient water has been distilled off to leave approximately 12% -18% based on the NMMO, thereby which is formed a cellulose solution. The resulting spinnable paste should contain from about 8% to about 15% cellulose.

[0062] The heated aqueous solution 20 is then directed to a spinning paste delivery mechanism 24, such as for example an extruder, where it is routed to pass through a matrix / row holder assembly 26. The matrix / row holder assembly 26 may be fixed directly to the spinning paste supply mechanism 24, or it may be distanced from the spinning paste supply mechanism 24.

[0063] It should be noted that, although the preparation of the aqueous solution 20, consisting of cellulose 16 and a water-soluble solvent 18, such as aqueous NMMO, is known to those skilled in the art, the apparatus and the method for spinning the Aqueous solution 20 heated to convert it into cellulose fibers 12 is very unique. So far no one has been able to form cellulose fibers 12 each having a diameter of less than about 15 microns at a rate of more than 0.1 grams / hole / minute and with a production speed of up to about 750 meters per minute. In addition, no one has been able to form very fine cellulose fibers 12 each having a diameter of less than about 5 microns at a rate of more than 0.5 grams / hole / minute and with a production speed of up to about 750 meters per minute.

[0064] Referring now to Fig. 2, the matrix / row holder assembly 26 includes a matrix holder 28 having a first conduit 30 formed therein through which the heated aqueous solution 20 is routed. The matrix holder 28 also has at least one second conduit 32 formed therein. In Fig. 2 a couple of second ducts 32 are shown spaced apart from each other. Each of the second ducts 32 is sized and configured to route or direct a compressed gas 34 therethrough. As desired, the compressed gas 34 is air.

[0065] Those skilled in the art will understand that two, three, four or more second ducts 32 can be used. For better distribution of the compressed gas 34, multiple second spaced apart ducts 32 can be used.

[0066] Compressed gas 34 is normally heated to a high predetermined temperature. The compressed gas 34 can be heated to a temperature between about 100 ° C and about 160 ° C. As desired, the compressed gas 34 is heated to a temperature ranging from about 110 ° C to about 160 ° C. According to what is most desirable, the compressed gas 34 is heated to a temperature ranging from about 120 ° C to about 160 ° C. As most desirable, the compressed gas 34 is heated to a temperature of about 120 ° C. The compressed gas 34 should have a speed of at least about 45 meters per second (m / sec.). As desired, the compressed gas should have a speed of approximately 45 m / sec. at approximately 500 m / sec. According to what is most desirable, the compressed gas 34 should have a speed of approximately 50 m / sec. at approximately 450 m / sec.

[0067] It should be apparent to one skilled in the art that the cross-sectional area, internal shape and internal configuration of each of the ducts 32 may vary. The inside diameter of each of the ducts 32, the material from which each of the conduits 32 is made, the back pressure of the compressed gas 34 and the temperature of the compressed gas 34, as well as other factors, will influence the speed of the compressed gas 34.

[0068] The matrix / row holder assembly 26 also includes a filter block 36 that is fixed to the matrix holder 28. The filter block 36 has at least two separate passages 38 and 40 formed therethrough. The passage 38 is sized and configured to be married and aligned with the first conduit 30, so that the heated aqueous solution 20 can be routed through the filter block 36. The other passages 40, of which two are illustrated, are dimensioned and configured to match and be aligned with the two second ducts 32, so that the compressed gas 34 can be routed through the filter block 36. It should be understood that the size and shape of the passages 38 and 40 do not have to be identical to the size and shape of the first and second ducts 30 and 32, respectively. However, the number of passages 40 must be equal to the number of conduits 32 and each passage 40 must be aligned with one of the conduits 32.

[0069] Filter block 36 serves to filter particulate substance, such as undissolved pulp, solution impurities, etc., in order to separate it from the aqueous solution 20.

[0070] Referring to Figs. 2 and 3, the matrix / row holder assembly 26 further includes a first element 42 which may be a row. The first element 42 is fixed to the filter block 36. The filter block 36 is sandwiched between the matrix holder 28 and the first element or row 42. The first element 42 has multiple nozzles 44 arranged in rows and / or columns or according to any other desired layout. Each of the nozzles 44 may be made of a metal such as steel, stainless steel, a metal alloy, a ferric metal, etc. As desired, each of the nozzles 44 is made of stainless steel. Each of the nozzles 44 is illustrated as an elongated hollow tube 46. By "tube" is meant a hollow cylinder, such as especially one that conveys fluid or functions as a passage. Each of the hollow cylindrical tubes 46 has a longitudinal central axis X-X and a uniquely shaped cross section. As desired, the cross section is circular, but a cross section of almost any geometric shape can be used. The cross section should be constant. Each of the hollow cylindrical tubes 46 has an inner diameter d and an outer diameter d1. The inner diameter d may be from about 0.125 millimeters (mm) to about 1.25 mm. The outer diameter d1 should be at least about 0.5 mm. As desired, the outer diameter d1 of each of the hollow cylindrical tubes 46 may be located within a range of values ranging from about 0.5 mm to about 2.5 mm.

[0071] The heated aqueous solution 20 is extruded through the inner diameter d of each of the hollow cylindrical tubes 46. The back pressure in the heated aqueous solution 20 that is present in the passage 38 of the filter block 36 or in each of the hollow cylindrical tubes 46 should be equal to approximately 5 bars or more. "Bar" means a unit of pressure that is equal to one million (106) dynes per square centimeter. As desired, the back pressure in the heated aqueous solution 20 that is present in each of the hollow cylindrical tubes 46 may be from about 20 bars to about 200 bars. According to what is most desirable, the back pressure in the heated aqueous solution 20 that is present in each of the hollow cylindrical tubes 46 can be from about 25 bars to about 150 bars. According to what is even more desirable, the back pressure in the heated aqueous solution 20 that is present in each of the hollow cylindrical tubes 46 can be from about 30 bars to about 100 bars.

[0072] The first element or row 42 also has at least one other passage 48 formed therein. In Fig. 2 two spaced passages 48 are shown, each of which is sized and configured to be aligned with one of the two passages 40 formed through the filter block 36. The passages 48 are connected to a widened chamber 50 formed on a surface of the first element or row 42. The elongate chamber 50 may be centrally located around the longitudinal central axis XX of each of the hollow cylindrical tubes 46. The widened chamber 50 is aligned and distanced on the side opposite to that of the surface of the first element or row 42 that is fixed to the filter block 36. The size, depth and shape of the widened chamber 50 may vary. As desired, the widened chamber 50 has a circular shape with a depth of at minus 0.1 inches. According to what is most desirable, the widened chamber 50 has a circular shape with a depth of at least 0.2 inches. The passages 48 serve to direct the compressed gas 34 of the passages 40 to the widened chamber 50 of the row 42.

[0073] It should be understood that since the number of passages 40 formed in the filter block 36 may vary, the number of passages 48 formed in the first element or row 42 may also vary. As desired, there will be an equal number of passages. 48 formed in the first element or row 42 so that they are in correspondence and aligned with the number of passages 40 formed in the filter block 36. As stated above, a better distribution of the compressed gas 34 may be possible when use a greater number of passages 40 and passages 48. For example, twelve passages 40 can be formed in the filter block 36, and each can be aligned with one of the twelve passages 48 formed in the first element or row 42. Each of the twelve passages 40, as well as each of the twelve passages 48, may be approximately 30 degrees apart from an adjacent passage 40 or passage 48, respectively, in a front view of the block of filter 36 and the first element or row 42. A better distribution of compressed gas 34 is correlated with obtaining cellulose fibers 12 more uniformly.

[0074] Still referring to Fig. 2, the matrix / row holder assembly 26 additionally includes a second element made in the form of a gas distribution plate 52. The second element is fixed to the first element or row 42. The first element or row 42 is sandwiched between the filter block 36 and the second gas distribution element or plate 52. The second gas distribution element or plate 52 has multiple aisles 54 formed therein. The second gas distribution element or plate 52 also has a chamber 56 that is aligned and spaced apart from the surface of the second gas distribution element or plate 52 that is fixed to the first element or row 42. The aisles 54 connect the widened chamber 50 to the chamber 56. The chamber 56 may be centrally located around the longitudinal central axis XX of each of the hollow cylindrical tubes 46. The size, depth and shape of the chamber 56 may vary. The aisles 54 serve to route the compressed gas 34 through the second gas distribution element or plate 52. The second gas distribution element or plate 52 also has multiple openings 58 formed therein that are independent and distinct from the aisles 54. Each of the multiple openings 58 is sized to allow one of the multiple nozzles to pass through it. 44, made in the form of elongated hollow cylindrical tubes 46. As desired, each of the multiple openings 58 has a circular section with a diameter d2 that is greater than the outer diameter d1 of each of the hollow cylindrical tubes 46. In other words, the outer diameter d1 of each of the hollow cylindrical tubes 46 does not form a forced or tight fit with the inner diameter d2 of each of the multiple openings 56.

[0075] It should be understood that additional passages or smaller holes can also be formed in the second gas distribution element 52 to allow the passage of compressed gas therethrough.

[0076] Referring again to Figs. 2 and 3, the matrix / row holder assembly 26 includes a third element that is made in the form of an outer plate 60. The third outer element or plate 60 is fixed to the second gas distribution element or plate 52. The second gas distribution element or plate 52 is sandwiched between the first element or row 42 and the third external element or plate 60. The third external element or plate 60 has multiple first openings 62 formed therethrough. Each of the first multiple openings 62 is sized to allow one of the multiple nozzles 44, made in the form of elongated hollow cylindrical tubes 46, to pass freely therethrough; see Fig. 3. Each of the hollow cylindrical tubes 46 may extend outwardly or downwardly beyond the third outer element or plate 60. The distance along which the free end of each of each can vary the hollow cylindrical tubes 46 reach beyond the outer plate 60. Alternatively, each of the hollow cylindrical tubes 46 can end near the third element or outer plate

60

[0077] Each of the nozzles 44 has a first opening 62 formed next to it. As desired, each of the first openings 62 is concentrically aligned around each of the nozzles 44. Each of the first multiple openings 62 may have a uniquely shaped cross section with an inner diameter d2, see Fig. 3. As desired, each of the first multiple openings 62 has a circular cross section. The inner diameter d2 of each of the first openings 62 may vary. As desired, each of the first openings 62 has the same inner diameter d2. According to what is most desirable, the inner diameter d2 of each of the first openings 62 is at least 7.5 mm. According to what is even more desirable, the inner diameter d2 of each of the first openings 62 is at least 10 mm. As most desirable, the inner diameter d2 of each of the first openings 62 is at least 12 mm.

[0078] The inner diameter d2 of each of the first openings 62 should be greater than the outer diameter d1 of each of the hollow cylindrical tubes 46. Each of the first openings 62 is connected to the chamber 56 formed in the second gas distribution element or plate 52. Each of the first openings 62 is capable of emitting compressed gas 34 therethrough such that the compressed gas 34 at least partially surrounds the heated aqueous solution 20 extruded from each of the nozzles 44. As desired, each of the first openings 62 completely surrounds the heated aqueous solution 20 extruded from each of the nozzles 44 and this compressed air wraps or forms a curtain around the heated aqueous solution 20 extruded from each of the nozzles 44.

[0079] Referring to Figs. 2 and 4, the third element or outer plate 60 also has multiple second openings 64 formed therein which are connected to the chamber 56 formed in the second gas distribution element or plate 52. Each of the multiple second openings 64 has a unique cross-section through which the compressed gas 34 can be emitted. As desired, each of the multiple second openings 64 has a circular cross-section. Each of the multiple second openings 64 has an inside diameter d3. As desired, the inner diameter d3 is of a single dimension. The inner diameter d3 of each of the multiple second openings 64 may vary. As desired, the inner diameter d3 of each of the multiple second openings 64 is of the same dimension. According to what is most desirable, the inner diameter d3 of each of the second openings 64 is equal to the inner diameter d2 of each of the first openings 62. According to what is more desirable, the inner diameter d3 of each of the second openings 64 is at least 0.75 mm. According to what is even more desirable, the inner diameter d3 of each of the second openings 64 is at least 1.0 mm. According to what is most desirable, the inner diameter d3 of each of the second openings 64 is at least 1.2 mm.

[0080] Each of the second openings 64 may be positioned next to one of the first openings 62. Each and every one of the first and second openings 62 and 64 are aligned and parallel to each other. Alternatively, two or more of each of the second openings 64 may be positioned next to one of the first openings 62. In some embodiments, they may be positioned next to one of the first openings 62 from three (3) to eight (8 ) of the second openings 64. In addition, each of the second openings 64 may also be positioned next to one of the nozzles 44 in each of the rows or in each adjacent row. Many different arrangements or groupings can be used in which the arrangement of the first and second multiple openings 62 and 64 can be varied respectively.

[0081] Each of the second openings 64 is spaced at a distance between approximately 1 mm and approximately 3.8 mm of the longitudinal central axis X1-X1 of each of the nozzles 44. As desired, each of the second openings 64 are spaced at a distance between approximately 1 mm and approximately 2.5 mm of the longitudinal central axis X1-X1 of each of the nozzles 44.

[0082] Referring to Figs. 2 and 4, each of the multiple second openings 64 may have a stationary elongated central needle or rod 66 positioned therein. The elongated central needle 66 has a constant outside diameter d4 and is fixed to row 42; see Fig. 2. The diameter d4 of the central needle 66 may vary. As desired, the diameter d4 of the central needle 66 is at least 0.25 mm. According to what is most desirable, the diameter d4 of the central needle 66 is at least 0.5 mm. According to what is even more desirable, the diameter d4 of the central needle 66 is at least 0.64 mm. As most desirable, the diameter d4 of the central needle 66 is at least 0.75 mm.

[0083] Referring to Fig. 5, as illustrated, the stationary central needle 66 is positioned such that it is parallel and adjacent to one of the hollow cylindrical tubes 46. The compressed gas 34 can follow a straight or tortuous path. through the second gas distribution element or plate 62 and the third external element or plate 60, such that it will form a wrap, cover or curtain of compressed gas 34 around at least a part of the circumference of the hollow cylindrical tube 46. "Wrapping" means something that hides, protects or shields it. In addition, the compressed gas 34 exiting the adjacent second opening 64 will provide a barrier or veil that will limit or prevent the heated aqueous solution 20, extruded outside each of the nozzles 44, that is, from the hollow cylindrical tubes 46, contact, touch and / or join the heated aqueous solution 20 extruded from an adjacent nozzle 44. The word "veil" means something that hides, separates or shields it like a curtain. Briefly said, the compressed gas 34 emitted through the multiple second openings 64 will form compressed gas streams that will limit or prevent the individual molten filaments from joining one or more other molten filaments and forming ropes and / or bundles. As desired, the compressed gas 34 can form a wrap, cover

or curtain around the entire circumference of each of the hollow cylindrical tubes 46. The speed and pressure of the compressed gas 34 can be varied as appropriate for the equipment available.

[0084] Even with reference to Fig. 5, it can be clearly seen that the hollow cylindrical tube 46 extends downwardly beyond the first opening 62 along a vertical distance d5 that is at least 1 mm. As desired, the vertical distance d5 is at least 3 mm, and according to what is most desirable, the vertical distance d5 is at least 5 mm.

[0085] In Figs. 4 and 5, each of the multiple second openings 64 completely surrounds the central needle 66 such that the compressed gas 34 can be emitted around the entire outer circumference of each of the central needles 66. It can be seen as the Compressed gas 34 leaving each of the second openings 64 wraps or forms a veil around or around the heated aqueous solution 20 extruded from each of the nozzles 44.

[0086] Referring now to Figs. 6 and 7, the central needle 66 in each of the second openings 64 has a constant outside diameter d4. In Fig. 6, the central needle 66 is coaxially aligned with the second opening 64 such that a side wall 82 of the second opening 64 is aligned with and parallel to the elongated central needle 66. The side wall 82 is also aligned perpendicularly to the second opening 64. In this embodiment, a uniform discharge of compressed gas is emitted around the entire circumference of the central needle 66

34. Alternatively, a second opening 64 ’having a venturi configuration may be used; see Fig. 7. "Venturi" means a narrowed throat in a gas passage used to increase the speed of the passing gas. Each of the multiple second openings 64 'has a side wall 84 that has a venturi-like shape. For example, the side wall 84 has a convex shape that can form a narrow passageway around or below the circumference of the center needle 66. The convex shape of the side wall 84 increases the speed of the compressed gas 34 passing therethrough. . This design may be desirable in some applications.

[0087] It should be noted that in Fig. 6 the terminal end of the central needle 66 is flush with the outer surface of the outer plate 60, while in Fig. 7 the terminal end of the central needle 66 is located inwards with respect to the outer surface of the outer plate 60. Alternatively, the terminal end of the central needle 66 may be located within the thickness of the outer plate 66.

[0088] Referring now to Figs. 8-12, are shown in the same alternative embodiments for the first opening 62. In Fig. 8 a first opening 68 is shown which has a square configuration with a hollow cylindrical tube 46 positioned therein. In Fig. 9 a first opening 70 is shown having a triangular configuration with a hollow cylindrical tube 46 positioned therein. A first opening 72 is shown in Fig. 10 having two sickle slits 74 spaced apart from a hollow cylindrical tube 46. In Fig. 11 a first opening 76 is shown having four shorter sickle slits 78 spaced apart from a hollow cylindrical tube 46 and each other. Finally, in Fig. 12 a first opening 80 is shown having a plurality of circular holes 83 spaced apart from a hollow cylindrical tube 46. In Fig. 12 ten circular holes are shown that are spaced at equal distance from each other. One skilled in the art will understand that the actual number of holes 83 may vary. Similarly, several arrangements may be used for the first openings 62.

[0089] referring to Fig. 13, there is shown therein an assembly 86 that includes a plurality of first openings 62 each having a nozzle 44 positioned therein, and a plurality of second openings 64 formed in the third outer element or plate 60. The assembly 86 has a longitudinal central axis X1-X1 and a transverse central axis Y1-Y1. The assembly 86 includes a plurality of columns 88 that are aligned parallel to the longitudinal central axis X1-X1 and a plurality of rows 90 that are aligned parallel to the transverse central axis Y1-Y1. In set 86, the number of columns 88 and the number of rows 90 may vary. The number of columns 88 may be greater than, equal to or less than the number of rows 90. As desired, the number of columns 88 is greater than number of rows 90. The number of columns 88 can be an even number or an odd number. Similarly, the number of rows 90 may be an even number or an odd number. The number of columns 88 can be between about 1 per row and about 1,000 per row. As desired, the number of columns 88 may be between about 2 per row and about 800 per row. According to what is most desirable, the number of columns 88 can be between about 10 per row and about 500 per row. According to what is even more desirable, the number of columns 88 can be between about 20 per row and about 250 per row. In Fig. 13, as illustrated the outer plate 60 has an even number of columns 88 and an even number of rows 90.

[0090] The number of rows 90 may be between about 1 per row and about 100 per row. As desired, the number of rows 90 may be between about 2 per row and about 50 per row. According to what is most desirable, the number of rows 90 may be between about 3 per row and about 25 per row. According to what is even more desirable, the number of rows 90 may be between about 6 per row and about 18 per row. As most desirable, the outer plate 60 will contain at least about 10 rows 90 per row. In Fig. 13 eighteen rows 90 are present.

[0091] It will also be noted that each of the nozzles 44, positioned in each of the columns 88, is displaced or disposed to the triplet with respect to a nozzle 44 positioned in an adjacent column 88. "Al tresbolillo" means located or as if located on alternate sides of a center line; that is put in a row or in zigzag rows. Similarly, each of the nozzles 44, positioned in each of the rows 90, is displaced or disposed to the pin with respect to a nozzle 44 positioned in an adjacent row 90. As desired, at least one of the nozzles 44 of one of the columns or rows 88 or 90 respectively is disposed to the pin with respect to at least one of the nozzles 44 that are present in an adjacent column or row 88 or 90, respectively . According to what is most desirable, at least two of the nozzles 44 of one of the columns or rows 88 or 90 respectively are disposed to the pin with respect to at least two of the nozzles 44 that are present in a column or row 88 or 90 adjacent, respectively. According to what is even more desirable, at least three of the nozzles 44 of one of the columns or rows 88 or 90 respectively are disposed to the pin with respect to at least three of the nozzles 44 that are present in a column or row 88 or 90 adjacent, respectively.

[0092] It has been recognized that in order to achieve a uniform high quality formation of the cellulose fibers 12 the nozzles 44 should be arranged to the three-roll so that, being the heated aqueous cellulose solution 20 extruded to be thus transformed into multiple fused filaments, each of the multiple fused filaments can remain independent and unique. By establishing a minimum distance between two adjacent nozzles 44, the molten filaments extruded therefrom will not touch or join together. The three-pin arrangement of the nozzles 44 also minimizes that the compressed gas streams leaving one of the nozzles 44 interfere with the compressed gas streams associated with an adjacent nozzle 44.

[0093] Even with reference to Fig. 13, the third element or outer plate 60 has at least about 8 of the first and second openings 62 and 64 respectively per linear centimeter. The number of first openings 62 may be equal to or different from the number of second openings 64. The inside diameter d2 of each of the first openings 62 may be equal to or different from the inside diameter d3 of the second openings 64 or 64 ’. As desired, the third element or outer plate 60 has at least about 20 of the first and second openings 62 and 64, respectively, per linear centimeter. According to what is most desirable, the third element or outer plate 60 has at least about 40 of the first and second openings 62 and 64, respectively, per linear centimeter. According to what is even more desirable, the third outer element or plate 60 has at least about 60 of the first and second openings 62 and 64, respectively, per linear centimeter. As most desirable, the third element or outer plate 60 has at least about 90 of the first and second openings 62 and 64, respectively, per linear centimeter.

[0094] It should be apparent to one skilled in the art that many different assemblies can be constructed and used. For example, in the third element or outer plate 60 an assembly could be formed that had at least six rows 90 per row and in which each of the rows 90 includes an equal number of first and second openings 62 and 64, respectively. Alternatively, an assembly that has at least ten rows 90 per row and in which each of rows 90 includes at least two of the first openings 62, that is, two of the elements, could be formed in the third element or outer plate 60 nozzles 44, and at least two of the second openings 68. In addition, in the third element or outer plate 60 a set could be formed having at least ten rows 90 per row and in which each of the rows 90 contains an unequal number of first and second openings 62 and 64, respectively.

[0095] Regardless of the set that is selected in particular, it should be noted that displacing one of the first openings 62, with one of the nozzles 44 located therein, in one of the columns 88 or rows 90, with respect to a of the first openings 62 that are present in an adjacent column 88 or row 90, the distance between the first adjacent openings 62 can be increased. Similarly, the distance between two adjacent nozzles 44 is also increased. As this distance is increased, the probability of an extruded molten filament from one of the nozzles 44 coming into contact with or touching an extruded molten filament from the adjacent nozzle 44 decreases. As illustrated in Fig. 3, each of the first openings 62 contains a nozzle 44. By limiting or preventing such contact, individual molten filaments can be formed that can be thinned so as to become very fine cellulose fibers. The word "lose weight" means to make more slender, thin or small. The different individual molten filaments are then coagulated, as will be explained later, in order to each form a soft solid cellulose fiber. "Coagular" means causing a transformation of a liquid into a soft solid mass.

[0096] Referring now to Fig. 14, a second assembly 92 is shown therein which includes a plurality of first openings 62 and a plurality of second openings 64 formed in the third element or outer plate 60. Each of the First openings 62 has a nozzle 44 positioned therein. The assembly 92 has a longitudinal central axis X2-X2 and a transverse central axis Y2-Y2. The assembly 92 includes a plurality of columns 94 that are aligned parallel to the longitudinal central axis X2-X2 and a plurality of rows 96 that are aligned parallel to the transverse central axis Y2-Y2. In assembly 92, the number of columns 94 and the number of rows 96 may be varied as explained above with reference to Fig. 13. A notable difference between assembly 86, shown in Fig. 13, and the set 92, shown in Fig. 14, is that in set 92 one of every two columns 94, as well as the two outer rows 96, contains (n) only the second openings 64. This creates a configuration wherein each of the nozzles 44 is surrounded by eight of the second openings 64. This means that eight streams of compressed gas are present to separate and wrap each molten filament extruded from each of the nozzles 44 in order to prevent it from entering in contact with or touch an adjacent molten filament. By keeping each molten filament isolated, the formation of ropes and / or bundles by the molten filaments can be limited or eliminated, and multiple fine cellulose fibers can be obtained.

[0097] Still referring to Fig. 14, it will also be noted that the outer columns 94, 94 on the left and right sides of the assembly 92 and the outer rows 96 at the top and bottom of the assembly 92 are exempt of the first openings 62 and of the nozzles 44. This configuration is not necessary but can help to limit the air turbulence at each end of the assembly 92. In addition, the air turbulence can be further limited by causing the two columns 94, 94 that They are located on the right side of the figure and are exempt from first openings 62 and nozzles 44, as shown. Similarly, the two outer columns 94, 94 can be made on the left side of the assembly, as well as the two outer rows 96, 96 that are at the top and bottom of the assembly 92 are also exempt from first openings 62 and nozzles 44.

[0098] Referring to Figs. 15-18, they are represented in the same four different sets. In Fig. 15, the third element or outer plate 60 contains a plurality of first and second openings 62 and 64, respectively. In this assembly, each of the first openings 62 contains a nozzle 44 and each of the first openings 62 is surrounded by three of the second openings 68 through which compressed gas is routed. This is called a "three hole" configuration. In Fig. 16, the third element or outer plate 60 contains a plurality of first and second openings 62 and 64, respectively. In this assembly, each of the first openings 62 contains a nozzle 44 and each of the first openings 62 is surrounded by four of the second openings 64 through which compressed gas is routed. This is called a "four hole" configuration. In Fig. 17, the third element or outer plate 60 contains a plurality of first and second openings 62 and 64, respectively. In this assembly, each of the first openings 62 contains a nozzle 44 and each of the first openings 62 is surrounded by six of the second openings 64 through which compressed gas is routed. Each of the second openings 64 is spaced approximately 60 degrees from an adjacent second opening 62. This is called the “six hole” configuration. In Fig. 18, the third element or outer plate 60 contains a plurality of first and second openings 62 and 64, respectively. In this assembly, each of the first openings 62 contains a nozzle 44 and each of the first openings 62 is surrounded by eight of the second openings 64 through which compressed gas is routed. Each of the second openings 64 is spaced approximately 45 degrees from an adjacent second opening 62. This is called the “eight hole” configuration.

[0099] referring to Figs. 1, 13 and 19, the process 10 additionally includes the step of directing the heated aqueous solution 20 through each of the nozzles 44 formed in the first element or row 42. The first element or row 42 has multiple rows 90 of first openings 62 each containing one of the nozzles 44. The first element or row 42 also has a plurality of second openings 64 formed therein. The first openings 62 differ from the second openings 64 in that each of the first openings 62 has a nozzle 44 positioned therein. In the first element or row 42, at least one of the nozzles 44, located in a row 90, is disposed to the pin with respect to at least one of the nozzles 44 located in an adjacent row 90. Each of the nozzles 44 is concentrically disposed within each of the first openings 62 and one or more of the second openings 64 are located next to each of the nozzles 44.

[0100] The heated aqueous solution 20 is extruded through the hollow cylindrical tube 46 of each of the nozzles 44 at a predetermined back pressure. The back pressure must be at least 10 bars to form a molten filament 98. The back pressure can be between about 10 bars and about 200 bars as explained above. The velocity of the heated aqueous solution 20 leaving the nozzle 44, including the adjacent air stream, should be at least about 100 meters per second. As desired, the velocity of the heated aqueous solution 20 leaving the nozzle 44, including the adjacent air stream, should be at least about 250 meters per second. According to what is most desirable, the velocity of the heated aqueous solution 20 leaving the nozzle 44 should be at least about 450 meters per second. The extruded molten filament 98 forms a thickening 100, see Fig. 19, immediately upon exiting the hollow cylindrical tube 46. They contribute to forming this thickening 100 a number of factors. Such factors include, but are not limited to, the following: friction between the aqueous solution 20 and the inner diameter d of the hollow cylindrical tube 46, the speed of the aqueous solution 20, the viscosity of the aqueous solution 20, the inner diameter d of the hollow cylindrical tube 46, the gravity acting in the aqueous solution 20, etc.

[0101] The extruded molten filament 98 is at least partially wrapped, and as desirable is completely enveloped, by the compressed gas 34 that is emitted through the first opening 62 surrounding each of the nozzles 44. The compressed gas 34 can be heated to a temperature of at least about 100 ° C. As desired, the compressed gas 34 is heated to a temperature of at least about 120 ° C. According to what is most desirable, the compressed gas 34 is heated to the same temperature as that of the heated aqueous solution 20. Compressed gas 34 is emitted in the form of gas streams 102 that are essentially aligned parallel to molten filament 98. Compressed gas streams form a veil or curtain about at least a part of the circumference of molten filament 98. According to Desirably, the compressed gas streams 102 form a veil or curtain around the entire circumference of the molten filament 98. The compressed gas 34, which as desired is air, is emitted from each of the first openings 62 at a speed at least 45 meters per second as explained above. Compressed gas streams 102, together with gravity, will thin and accelerate each of the molten filaments 98 thereby making it adopt a circular configuration in cross-section having a diameter of less than about 15 microns. As desired, each of the molten filaments 98 will have a diameter between about 0.5 microns and about 10 microns. According to what is most desirable, each of the molten filaments 98 will have a diameter between about 1 micron and about 8 microns. According to what is even more desirable, each of the molten filaments 98 will have a diameter between about 1 micron and about 5 microns. As most desirable, each of the molten filaments 98 will have a diameter between about 1 micron and about 3 microns.

[0102] Even with reference to Fig. 19, thinning and acceleration will occur within a predetermined distance h. The actual amount of weight loss and acceleration may vary. Both the amount of thinning and the acceleration can be calculated and adjusted to obtain a cellulose fiber 12 having a predetermined diameter. The distance h may vary depending on a number of factors, including, but not limited to, the following: the composition of the aqueous solution 20, the finishing diameter of the cellulose fibers, the temperature of the molten filament 98, the inner diameter of the hollow cylindrical tube 46, etc. The distance h can be between about 3 centimeters and about 3 meters. As desired, the distance h should be between about 15 centimeters and about 2 meters. According to what is most desirable, the distance h should be between about 20 centimeters and about 1.5 meters. According to what is even more desirable, the distance h should be between about 30 centimeters and about 1 meter.

[0103] The process 10 further includes the steps of extruding the heated aqueous solution 20 downwardly from each of the nozzles 44 parallel to a longitudinal central axis X3-X3 and bringing each of the molten filaments 98 into contact with a liquid 104. The liquid 104 causes each of the molten filaments 98 to coagulate so as to become a continuous solid fiber 12. The liquid 104 may be water, alcohol or a solution having a high concentration of water. The temperature of the liquid 104 can be adjusted to suit the particular needs of each case. For example, liquid 104 may be at room temperature. Alternatively, the liquid 104 could be at a temperature below room temperature. You can also vary the speed of the liquid

104. It has been found in some applications that using a pressurized liquid 104 produces a better chemical reaction between molten filaments 98 and liquid 104. For example, liquid 104 can be introduced in the form of a hydrochorro. The term "hydrochorro" means a jet of liquid under pressure or a mixture of liquid and air. The liquid 104 causes a greater part of the solvent 18 to be solvated in the liquid solution and thus allow the molten filaments 98 to coagulate or transform into a continuous solid fiber. The amount of solvent 18 that is actually removed by the liquid 104 may vary depending on the percentage of solvent 18 that is present in the heated aqueous solution 20. As desired, at least 75% of the solvent that is present in the heated aqueous solution 20 will be removed. According to what is most desirable, at least about 80% of the solvent that is present in the heated aqueous solution 20 will be removed. According to what is even more desirable, at least about 85% of the solvent that is present in the heated aqueous solution 20 will be removed. As most desirable, at least about 90% of the solvent that is present in the heated aqueous solution 20 will be removed.

[0104] For example, if the heated aqueous solution 20, leaving the nozzle 44, includes approximately 85% solvent, approximately 10% cellulose and approximately 5% water, then once the molten filament 98 has established contact with liquid 104, the percentages may vary from approximately 10% solvent, approximately 10% cellulose and approximately 80% water. In order to remove all solvent 18 that is present in each of the molten filaments 98, cellulose fibers 12 will normally have to be subjected to additional washing steps.

[0105] Each of the molten filaments 98 should be brought into contact with the liquid 104 at a distance h of at least about 3 centimeters from each of the nozzles 44. The liquid 104 can be introduced at an angle alpha a. The angle a can be between about 5 degrees and about 175 degrees measured from the longitudinal central axis X3-X3. As desired, the angle a can be between about 10 degrees and about 135 degrees measured from the longitudinal central axis X3-X3. According to what is most desirable, the angle a can be between about 25 degrees and about 90 degrees measured from the longitudinal central axis X3-X3. According to what is even more desirable, the angle a can be between about 30 degrees and about 60 degrees measured from the longitudinal central axis X3-X3. The angle a may be an acute angle or an obtuse angle measured from the hollow cylindrical tube 46.

[0106] Referring again to Figs. 2 and 19, each of the molten filaments 98 is extruded from each of the hollow cylindrical tubes 46 and each is thinned and accelerated by the compressed gas 34 leaving the first openings 62 in the form of compressed gas streams 102 Additional compressed gas 34 is emitted from each of the second openings 64. The compressed gas that is emitted from each of the second openings 64 limits or prevents the various individual molten filaments 98 from physically coming into contact with each other. This reduces the possibility that two or more of the molten filaments 98 may come into contact or touch each other and form ropes and / or bundles of filaments 98. It is desirable to keep each of the molten filaments 98 isolated and individualized with with respect to the adjacent molten filaments 98. By doing this, a multitude of individual cellulose fibers 12 can be produced which will all have essentially the same diameter.

[0107] The compressed gas 34 that is emitted through each of the second openings 64 will wrap the adjacent molten filaments 98 or help keep them separate from each other. The compressed gas 34 emitted from each of the second openings 64 can also be heated to have a high temperature. The temperature of the compressed gas 34 that is emitted from each of the second openings 64 may equal or almost coincide with the temperature of the compressed gas streams 102. Alternatively, the temperature of the compressed gas 34 that is emitted from each one of the second openings 64 may be a higher temperature or a lower temperature than the temperature of the compressed gas streams 102.

[0108] Similarly, the speed of the compressed gas 34 that is emitted from each of the second openings 64 can be adjusted to be less than, equal to, or greater than the speed of the compressed gas streams 102. As desired, the speed of compressed gas 34 that is emitted from each of the second openings 64 is essentially equal to the speed of compressed gas streams 102. In addition, the speed of compressed gas 34 that is emitted from each of the first and second openings 62 and 64, respectively, may be less than, equal to or greater than the speed of the heated aqueous solution 20 extruded from each of the nozzles 44. As desired, the speed of the compressed gas 34 that is emitted from each of the first and second openings 62 and 64, respectively, is greater than the velocity of the heated aqueous solution 20 extruded from each of the nozzles 44.

[0109] Still referring to Figs. 1 and 19, the continuous cellulose fibers 12 are still relatively soft and are still relatively wet when collected on a moving surface 106. The moving surface 106 may be a conveyor belt 108, as illustrated, or it may be some other type of movable element, such as a rotating drum. The moving surface 106, that is, the conveyor belt 108 or the rotating drum, can be porous so that water can thus easily pass through it. The moving surface 106 may be made such that it is capable of moving at different speeds. Upon entering the continuous and coagulated cellulose fibers 12 in contact with the moving surface 106, they will accumulate in order to form a non-woven fabric 110. The height or thickness t of the non-woven fabric 110, see Fig. 19, it will vary depending on the speed of the moving surface 106. For example, the lower the speed of the moving surface 106, the greater the height or thickness t of the nonwoven web 110. Similarly, when the speed is increased of the moving surface 106, the height or thickness of the nonwoven fabric 110 will decrease.

[0110] The distance between the nozzles 44 and the moving surface 106 is commonly referred to in the industry as the "matrix to collector" distance. This distance, indicated as h1 in Fig. 19, can be between about 15 centimeters and about 3 meters. As desired, the distance h1 is between about 20 centimeters and about 1 meter. According to what is most desirable, the distance h1 is between about 25 centimeters and about 120 centimeters. According to what is even more desirable, the distance h1 is between about 30 centimeters and about 90 centimeters. As most desirable, the distance h1 is at least 50 centimeters.

[0111] The nonwoven fabric 110 can be constructed to have an open pore structure. The size of the pores and the amount of pores may vary. The nonwoven fabric 110 may be a tangled accumulation of coagulated cellulose fibers 12. "Nonwoven" is understood to mean that the fibers 12 are not arranged or woven into a fixed configuration. The nonwoven fabric 110 may be made of 100% cellulose fibers 12, or it may be a combination of cellulose fibers 12 and polymer fibers. The polymer fibers (not illustrated) can be extruded from another extruder that is positioned in a location located upstream or downstream with respect to the matrix / row holder assembly 26; see Fig. 1. Polymer fibers may be polyolefin fibers, such as polyethylene or polypropylene fibers, or they may be two component fibers, etc. The percentage of different cellulose and polymer fibers may vary to suit the needs and requirements of each particular case.

[0112] It should be understood that cellulose fibers 12 can be combined with a polymer so as to also form a two component fiber.

[0113] Process 10 can be started by heating the aqueous solution 20 to a predetermined temperature. The aqueous solution 20 can be heated to an elevated temperature of between about 80 ° C and about 140 ° C. As desired, the aqueous solution 20 is heated to a temperature of at least 100 ° C. According to what is most desirable, the aqueous solution 20 is heated to a temperature of at least about 110 ° C. According to what is even more desirable, the aqueous solution 20 is heated to a temperature of about 120 ° C. Simultaneously or sequentially, the compressed gas 34 can be heated to an elevated temperature. The elevated temperature may be at least 100 ° C or more. As desired, the elevated temperature of the compressed gas 34 is approximately 110 ° C. According to what is even more desirable, the high temperature of the compressed gas 34 is about 120 ° C. The heated aqueous solution 20 is then directed through the matrix / row holder assembly 26 to the first element or row 42. In the first element or row 42, the heated aqueous solution 20 is extruded through each of those in the multitude of hollow cylindrical tubes 46 forming the nozzles 44. The heated aqueous solution 20 is extruded through each of the hollow cylindrical tubes 46 at a back pressure of between about 5 bars and about 200 bars. As desired, the back pressure is more than 20 bars. According to what is even more desirable, the back pressure is more than 30 bars. According to what is even more desirable, the back pressure is more than 40 bars. The heated compressed gas 34 is simultaneously routed through each of the first and second openings 62 and 64, respectively, at a speed of between about 1 meter per second and about 10 meters per second. The velocity of the heated compressed gas 34 is then gradually increased until the compressed gas 34 reaches a speed of at least about 45 meters per second. At this point in time, cellulose fibers 12 of a quality suitable for production can be extruded.

[0114] The process 10 can be stopped by disconnecting the heat used to heat the compressed gas 34. Then the speed of the compressed gas 34 is gradually reduced from about 45 meters per second to 0 meters per second. The flow of the heated aqueous solution 20 flowing through each of the nozzles 44 is then stopped. The heated aqueous solution 20 is then allowed to cool to room temperature. At this point in time the different pipes or hoses that lead to the aqueous solution 20 heated to the matrix / row assembly 26 can be swept or purged. It is important to sweep or purge such pipes or hoses, especially if the spinning paste supply mechanism 24 will be out of service for a prolonged period of time.

[0115] Referring to Fig. 20, there is shown a coagulated cellulose fiber 12 having a circular configuration in cross section with a diameter d6. The diameter d6 of the cellulose fiber 12 should be less than about 15 microns. As desired, the diameter d6 of the cellulose fiber 12 is less than about 10 microns. According to what is most desirable, the diameter d6 of the cellulose fiber 12 is between about 0.5 microns and about 8 microns. According to what is even more desirable, the diameter d6 of the cellulose fiber 12 is between about 0.5 microns and about 5 microns. As most desirable, the diameter d6 of the cellulose fiber 12 is between about 0.5 microns and about 4 microns.

[0116] Cellulose fiber 12 has a uniformly smooth outer surface 112 when viewed with 100 magnifications. Before coming into contact with the moving surface 106, the coagulated cellulose fiber 12 contains less than about 20% of the water-soluble solvent 18. In other words, the concentration of the solvent 18 is measured immediately after being the molten filament 98 coagulated to become a solid fiber

12. As desired, before contacting the moving surface 106, the coagulated cellulose fiber 12 contains less than about 15% of the water-soluble solvent 18. According to what is most desirable, before coming into contact with the surface 106 in motion, the coagulated cellulose fiber 12 contains less than about 10% of the water-soluble solvent 18. According to what is even more desirable, before coming into contact with the surface 106 in motion the coagulated cellulose fiber 12 contains less than approximately 8% of the water soluble solvent 18.

[0117] As mentioned above, each of the cellulose fibers 12 is made from a heated aqueous solution 20 which may vary in composition. The aqueous solution 20 may include between about 5% and about 35% cellulose, between about 60% and 90% of solvent 18, and between about 5% and about 35% water. Typically, the aqueous solution will contain about 10% cellulose, about 85% solvent and about 5% water. The most common water-soluble solvent 18 is N-methylmorpholine N-oxide (NMMO).

[0118] The heated aqueous solution 20 is extruded through the first element or row 42 at a rate of more than 0.1 grams / hole / minute and with a production speed of up to 750 meters per minute. As desired, the heated aqueous solution 20 is extruded through the first element or row 42 at a flow rate of more than 0.5 grams / hole / minute and with a production speed of up to 750 meters per minute. According to what is most desirable, the heated aqueous solution 20 is extruded through the first element or row 42 at a rate of more than 1 gram / hole / minute and with a production speed of up to 750 meters per minute. Immediately after being extruded from each of the nozzles 44, the heated aqueous solution 20 takes the form of a molten filament 98. The molten filament 98 is thinned and accelerated by gravity and adjacent adjacent compressed gas streams 102 of the first openings 62. Each of the molten filaments 98 is coagulated by the liquid 104 being thus transformed into a continuous solid fiber 12. This solid fiber 12 is still soft and moist and contains less than 20% of the water-soluble solvent 18.

[0119] Referring again to Fig. 1, the multiple continuous cellulose fibers 12 are collected on the moving surface 106 so as to form the cellulose nonwoven fabric 110. The cellulose nonwoven fabric 110 contains less than about 20% solvent. The non-woven cellulose fabric 110 has a basis weight of at least about 1 gram per square meter (g / m2). Alternatively, cellulose nonwoven fabric 110 has a basis weight of at least about 1.25 g / m2. Still as an alternative, the 110 non-woven cellulose fabric has a basis weight of at least about 1.5 g / m2 or more.

[0120] The non-woven cellulose fabric 110 is directed to a washing station 114 where an additional liquid, which is as desirable in the form of water, is contacted with the non-woven cellulose fabric 110. This additional liquid is mixing with the residual solvent 18 and reducing the concentration of solvent 18 to a percentage of less than 10%. As desired, the concentration of solvent 18 in cellulose fiber 12 is reduced to less than 5%. According to what is most desirable, the concentration of solvent 18 in cellulose fiber 12 is reduced to less than 3%. According to what is even more desirable, the concentration of solvent 18 in cellulose fiber 12 is reduced to less than 1%.

[0121] It should be noted that cellulose nonwoven fabric 110 can be passed through additional washing stations so that more than 99% of solvent 18 is removed.

[0122] After the solvent concentration 18 has been reduced to a preselected value or until practically all of the solvent 18 has been removed from the cellulose nonwoven fabric 110, the nonwoven fabric 110 is dried in a dryer 116. The fabric does not Cellulose fabric 110 can be dried using heated air, steam, moving air, contact with another element such as a felt or cloth, etc. Other methods than those known to those skilled in the art can also be used to dry cellulose nonwoven fabric 110.

[0123] Each of the cellulose fibers 12 is white or dirty white. A dye may be added to the heated aqueous solution 20 or to the molten filaments 98 so as to form cellulose fibers 12 of a particular color, if that is what is desired.

[0124] The dried cellulose 110 nonwoven fabric may be subjected to other mechanical methods, if desired. For example, cellulose nonwoven fabric 110 may be hydroentangled. In addition, cellulose nonwoven fabric 110 can be subjected to any process used in papermaking, including, but not limited to, the following: it can be punched, it can be punched, it can be stamped, it can be embossed, can be printed, can be coated, etc. After being treated in this way, the non-woven cellulose fabric 110 can be rolled up to be in the form of a supply roll 118. The supply roll 118 can be loaded and transported in a semi-trailer or in a railroad car to a manufacturer, distributor or consumed, or the supply roll 118 may be stored until ready to be sent to a consumer.

[0125] While the invention has been described in conjunction with several specific embodiments, it should be understood that in the light of the above description many alternatives, modifications and variations will be obvious to those skilled in the art. Accordingly, it is intended that this invention include all those alternatives, modifications and variations that remain within the spirit and scope of the appended claims.

[0126] In summary, an apparatus for extruding cellulose fibers is disclosed. The apparatus includes a first element, a second element and a third element that are all fixedly connected to each other. Multiple nozzles extend outward from the first element and each is designed to direct an aqueous solution of cellulose through it. Being the extruded aqueous solution, it is thinned and accelerated by compressed gas that flows through the first element and the second element and exits through the first openings formed in the third element. The compressed gas surrounds at least partially each nozzle and protects the molten filaments extruded therefrom. The third element also has multiple second openings formed therein which are also connected to a source of compressed gas. Compressed gas streams leaving each of the second openings serve to prevent each of the molten filaments from contacting an adjacent molten filament.

[0127] A process of cellulose fiber formation is also disclosed. The process includes the step of extruding an aqueous solution of cellulose and a solvent through a first element in order to form molten filaments. The first element has multiple rows of first and second openings with a nozzle positioned in each of the first openings. At least one of the nozzles of a row is disposed to the triplet with respect to at least one of the nozzles of an adjacent row. At least a part of each of the molten filaments is wrapped in a compressed gas emitted through each of the first openings. Each of the molten filaments is contacted with a liquid to remove some of the solvent and transform each of the molten filaments into a continuous solid fiber. The solid continuous fibers are then collected on a moving surface so as to form a cellulose nonwoven fabric.

Claims (16)

1. Device (26) for extrusion of cellulose fibers (12) comprising: a) a first element (42) having multiple nozzles (44) arranged in rows, each of said nozzles (44) having an inner diameter through which an aqueous solution (20) consisting of cellulose (16) can be extruded ) and a solvent (18), and formed through said first element (42) at least one passage (48) through which a compressed gas (34) can be routed; b) a second element (52) fixed to said first element (42), said second element (52) having multiple passages (54) formed therethrough which remain connected to said passage (48) which is at least one and is formed in said first element (42), and formed through said second element (52) multiple openings (58) through which each of said multiple nozzles (44) can pass; and c) a third element (60) fixed to said second element (52), said third element (60) having multiple first openings (62) formed therethrough, each of said multiple first first openings (62) being sized to allow one of said multiple nozzles (44) passes through it, each of said multiple first openings (62) being concentrically aligned around each of said multiple nozzles (44), each of said multiple first openings (62) being connected to said passages (54) for compressed gas formed in said second element (52) and each of said multiple first openings being able to emit compressed gas (34) therethrough such that said compressed gas (34) surrounds the less partially to said aqueous solution (20) extruded from each of said multiple nozzles (44), and said third element (60) also having multiple second openings (64) formed therethrough that remain with connected to said corridors (54) for compressed gas formed in said second element (52), each of said multiple second openings (64) positioned next to one of said multiple nozzles (44), and each of said multiple second openings (64) a diameter through which said compressed gas (34) can be emitted, characterized by the fact that multiple needles (66) are arranged next to said multiple nozzles (44), each of said multiple needles (66) passing through one of said multiple aisles (54) and each of said multiple second second openings (64) being larger than each of said multiple needles (66).

2.

The apparatus of claim 1, further comprising a filter block (36) fixed between a matrix holder (28) and said first element (42), said filter block (36) having a first passage (38) formed therein. whereby an aqueous solution (20) consisting of cellulose (16) and a solvent (18) can be routed, and formed therein a second passage (40) through which a compressed gas (34) can be routed.

3.

The apparatus (26) of claim 2, wherein said matrix holder (28) has formed therein a first conduit (30) through which an aqueous solution (20) consisting of cellulose (16) and a solvent (25) can be routed 18), and formed therein a second conduit (32) through which a compressed gas (34) can be routed, and said compressed gas (34) can pass through said apparatus (26) at a speed of at least 45 meters per second and each of said first multiple openings (72) includes at least two sickle slits (74).

Four.

The apparatus of claim 1, wherein each of said multiple nozzles (44) is made of stainless steel, and each of said multiple second openings (64) has a venturi formed therein.

5.

Process (10) of forming a cellulose nonwoven fabric (14), comprising the steps of: a) forming an aqueous solution (20) of cellulose (16) and a solvent; b) directing said aqueous solution (20) through a first element (42) having multiple nozzles (44) arranged in rows (90), each of said nozzles (44) having an inner diameter through which it passes said aqueous solution (20), said first element (42) having multiple needles (66) arranged next to said multiple nozzles (44), and said first element (42) having at least one passage (48) through which a compressed gas (34), of a second element (52) fixed to said first element (42), said second element (52) having multiple passages (54) formed therethrough which are connected to said passage (48) which is at minus one and is formed in said first element (42), each of said multiple needles (66) passing through one of said multiple aisles (54) and multiple openings (58) formed through said second element (52 ) through which each of said multiple nozzles (44) can pass, and from a third element (60) fixed to said second element (52), said third element (60) having multiple first openings (62) formed therethrough, each of said first openings (62) being sized to allow one of said multiple nozzles (44) pass through it, each of said first openings (62) being concentrically aligned around each of said multiple nozzles (44), each of said first openings (62) being connected to said aisles ( 54) for compressed gas formed in said second element (52) and each of said first compressed gas openings (34) emitting therethrough such that said compressed gas (34) at least partially surrounds said aqueous solution (20) extruded from each of said multiple nozzles (44), and said third element (60) also having multiple second openings (64) formed therethrough which are connected to said passageways (54) for compressed gas

formed in said second element (52), each of said multiple second openings (64) being larger than each of said multiple needles (66) and each of said multiple second openings (64) positioned next to one of said multiple nozzles (44), and each of said multiple second openings (64) having a diameter through which said compressed gas (34) is emitted; c) extruding said aqueous solution (20) through each of said nozzles (44) in order to form multiple filaments (98); d) wrapping at least a portion of each of said filaments (98) in a compressed gas (34) emitted through each of said first and second openings (62, 64) aligned adjacently; e) thinning said filaments (98) in order to make them adopt in a cross section a circular configuration having a diameter (d6) of less than about 15 µm (microns); f) putting said filaments (98) in contact with a liquid (104), said liquid (104) being mixed with said solvent (18) to remove some of said solvent (18), whereby each of said filaments (98 ) is transformed into a continuous solid fiber (12); and g) collecting said continuous solid fibers (12) on a moving surface (106) so as to form a cellulose nonwoven fabric (110).

6.

The process (10) of claim 5, further comprising the steps of heating said aqueous solution (20) to a temperature between 80 ° C and 140 ° C and heating said compressed gas (34) to a temperature of at least 120 ° C, and extruding said aqueous solution (20) through each of said nozzles (44) at a rate of more than 0.1 grams / hole / minute.

7.

The process (10) of claim 5, further comprising the steps of emitting said compressed gas (34) through each of said first openings (62) at a speed of at least 45 meters per second and emitting said compressed gas (34) through each of said second openings (64) at a speed of at least 45 meters per second.

8.

The process (10) of claim 5, further comprising the steps of extruding said aqueous solution

(20) downwards from each of said nozzles (44) parallel to a longitudinal central axis (X) and placing each of said filaments (98) in contact with water (104) introduced at an angle ( a) between 5 degrees and 175 degrees, said water (104) making each of said filaments (98) coagulate in order to transform a continuous solid fiber (12).

9.

The process (10) of claim 5, further comprising the step of initiating said process by performing the following steps: a) heating said aqueous solution (20) to a predetermined temperature of more than 80 ° C; b) directing said heated aqueous solution (20) to said first element (42) and extruding said heated aqueous solution (20) through each of said nozzles (44) at a back pressure of at least 10 bars; c) route said compressed gas (34) through each of said first and second openings (62, 64) at a speed of between 1 meter per second and 10 meters per second; d) heating said compressed gas (34) to a temperature of approximately 100 ° C; and e) gradually increasing said speed of said heated compressed gas (34) until said compressed gas (34) reaches a speed of at least about 45 meters per second.

10.

The process (10) of claim 5, further comprising the step of stopping said process by performing the following steps: a) disconnecting said heat used to heat said compressed gas (34); b) gradually reduce said speed of said compressed gas (34) to 0 meters per second; c) causing said aqueous solution (20) to stop flowing through each of said nozzles (44); and d) allowing said aqueous solution (20) to cool to room temperature.

eleven.

Use of a set (86) of nozzles (44) for extruding multiple cellulose fibers (12), said assembly (86) comprising: a) a first element (42) having multiple nozzles (44) arranged in rows (90) , each of said multiple nozzles (44) having a longitudinal central axis and each of said multiple nozzles including a tube (46) with a cross section having a diameter through which an aqueous solution (20) consisting of cellulose (16) and a solvent (18) can be extruded to be thus converted into a filament (98), said first element (42) also having multiple needles (66) arranged next to said multiple nozzles (44), and having said first element (42) at least one passage (40) through which a compressed gas (34) is routed; b) a second element (52) fixed to said first element (42), said second element (52) having multiple passages (54) formed therethrough which are connected to said passage (40) which is at least one and is formed in said first element (42), each of said multiple needles (66) passing through one of said multiple aisles (54), and multiple openings (58) being formed through said second element (52) through which passes each of said multiple nozzles (44);

c) a third element (60) fixed to said second element (52), said third element (60) having multiple first openings (62) formed therethrough, each of said first openings (62) being sized to allow it to pass through one of said multiple nozzles (44), each of said first openings (62) being concentrically aligned around each of said multiple nozzles (44), each of said first openings (62) being connected to said corridors (54) for compressed gas formed in said second element (52) and each of said first compressed gas openings (34) emitting therethrough such that said compressed gas (34) at least partially surrounds said aqueous solution ( 20) extruded from each of said multiple nozzles (44), and said third element (60) also having formed therethrough multiple second openings (64) which are connected to said corridors (54) for compressed gas formed in said second element (52), each of said multiple second openings (64) being larger than each of said multiple needles (66) and each of said multiple second openings (64) positioned next to one of said multiple nozzles (44), and each of said multiple second openings (64) having a diameter through which said compressed gas (34) is emitted, and where there are at least three of said second openings (64) that are each distanced towards the outside of each of said first openings (62), each of said second openings (64) emitting a stream of compressed gas (102) which is essentially parallel to said longitudinal central axis of each of said multiple nozzles ( 44), and each of said compressed gas streams (102) serving to wrap one of said extruded filaments (98).

12.

The use of claim 11, wherein said compressed gas (34) emitted from each of said first openings (62) thins and accelerates each of said filaments (98) extruded from each of said tubes (46) thus converting it in a continuous fiber (12) having a diameter (d6) of less than 15 µm (microns).

13.

The use of claim 12, comprising the operation of using the apparatus (26) of claim 1 at a rate of more than 0.1 grams / hole / minute, wherein said extruded cellulose fibers (12) have a diameter (d6) between 0�5 and �! m.

14.

The use of claim 11, wherein said first and second individual openings (62, 64) are aligned parallel to each other, and each of said second openings (64) is spaced at a distance between 1 millimeter and 4 millimeters of said central longitudinal axis of said nozzle (44).

fifteen.

The use of claim 14, wherein each of said second openings (64) is spaced at a distance between 1 millimeter and 2 millimeters of said longitudinal center axis of one of said nozzles (44), each of said second openings (64) contains a venturi, and each of said tubes (46) is a hollow cylindrical tube (46) that is made of stainless steel and extends downwardly beyond said first openings (62) exceeding them by at least 1 millimeter.

16.

The use of claim 11, wherein said multiple nozzles (44) are arranged in rows (90), each of said nozzles (44) including a hollow cylindrical tube (46) having a cross section and a constant diameter and is positioned therein, said aqueous solution (20) being extruded therethrough, and each of said first openings (62) being concentrically aligned around each of said hollow cylindrical tubes (46) and each having said first openings a cross section with a constant diameter, said diameter of each of said first openings (62) being greater than said diameter of each of said hollow cylindrical tubes (46), and each of said first openings (62) emitting ) through it compressed gas (34) that at least partially surrounds said extruded filament (98); said second openings (64) being arranged in said rows (90) with said multiple nozzles (44), at least two of said second openings (64) being positioned next to one of said nozzles (44) in each of said rows ( 90), each of said second openings (64) emitting a compressed gas (34); and at least one of said nozzles (44) of a row (90) being displaced with respect to one of said nozzles (44) of an adjacent row (90).