Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/06—Wet spinning methods
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/12—Stretch-spinning methods
  • D01D5/14—Stretch-spinning methods with flowing liquid or gaseous stretching media, e.g. solution-blowing
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F2/00—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof

Definitions

• the invention relates to a process for the production of cellulosic fibers, in which a solution of cellulose in a tertiary amine oxide is spun in a warm state into filaments which are passed through an air gap and are subsequently brought into contact with a precipitant in order to precipitate the cellulose, whereby the filaments are withdrawn by exerting a force and stretched in the air gap, which force is exerted on the precipitant by flowing the precipitant in the direction in which the filaments are withdrawn and bringing the filaments into contact with the precipitant.
• the invention also relates to an apparatus for performing the method.
• tertiary amine oxides are able to dissolve cellulose and that cellulosic moldings can be obtained from these solutions by precipitation.
• a method for producing such solutions is known for example from EP-A - 0 356 419.
• a suspension of cellulose in an aqueous tertiary amine oxide is first prepared.
• the amine oxide contains up to 40% by mass of water.
• the aqueous cellulose suspension is heated and water is drawn off under reduced pressure until the cellulose dissolves.
• the process can be carried out in a thin film treatment apparatus.
• a spinning process is known, according to which the freshly spun filaments are brought into contact with a precipitant which is allowed to flow in the direction in which the filaments are drawn off.
• DE-C - 195 12 053 also discloses a process for the production of cellulosic fibers, in which the freshly extruded filaments are introduced into a precipitation bath which is accelerated to a predetermined speed and at least approximately laminar in the direction of the extruded filaments. The filaments are drawn off from a spool.
• air should not only mean air as such, but also any gas or gas mixture which is inert to the filaments and does not interfere with spinning in any other way. Accordingly, a gas other than air can also be present in the "air gap".
• a method of the type described at the outset is known from EP-A-0 574 870.
• This process is carried out with a so-called spinning funnel, in which the freshly extruded filaments are warped with the aid of a liquid, flowing precipitant. The flow of the precipitant is caused by gravity.
• the disadvantage is this method that only relatively low-viscosity cellulose solutions, which moreover have a relatively low cellulose concentration of only 7.8% by mass, 6.1% by mass and 10.5% by mass, can be spun. From an economic point of view, such low cellulose concentrations are unsatisfactory, since they require low solution production capacity and high evaporation costs when working up the used precipitant.
• the object of the present invention is to further develop a method of the type mentioned at the outset in such a way that a high output can be achieved and highly concentrated, highly viscous cellulose solutions can be processed.
• the process according to the invention for the production of cellulosic fibers in which a solution of cellulose in a tertiary amine oxide in the warm state is spun into filaments, which are passed through an air gap and then brought into contact with a precipitant in order to precipitate the cellulose, the filaments drawn off by exerting a force and stretched in the air gap, which force is exerted with the precipitant, by allowing the precipitant to flow in the direction in which the filaments are drawn off and the filaments are brought into contact with the precipitant, is characterized in that that the precipitant is allowed to flow at a rate at least as large as, and when it is brought into contact with the filaments is in particular greater than the speed at which the filaments are drawn off.
• the invention is based on the knowledge that highly viscous cellulose solutions with cellulose concentrations of at least 12% by mass without a mechanical stretching device, such as e.g. a take-off godet, that is to say only with the kinetic energy transferred from the flowing precipitant to the filaments.
• a mechanical stretching device such as e.g. a take-off godet
• the filaments are passed through a so-called injector, into which precipitant which accelerates the filaments is injected at a pressure which is above the ambient pressure.
• the removal speed is obtained in a known manner from the desired titer of the filaments, the concentration of the cellulose solution and the output of the cellulose solution.
• the filaments are preferably wetted with precipitant before they are brought into contact with the flowing precipitant, which exerts the pulling force on them.
• the precipitant with which the filaments are wetted can be the same precipitant with which the force for stretching is exerted on the filaments. But it can also be different.
• the filaments In order to enable spinning in the dense filament structure, it is expedient for the filaments to be cooled in the air gap by blowing with a cooling gas, the cooling being carried out immediately after spinning.
• the blowing can be done with moist air.
• N-methylmorpholine-N-oxide is advantageously used as the tertiary amine oxide in the process according to the invention.
• the invention also relates to a method for producing a spunbonded nonwoven, which is characterized in that the cellulosic fibers produced according to the invention are laid to form a nonwoven which is consolidated.
• the fleece can be consolidated by treatment with a water jet. However, it can also advantageously be solidified by soaking it with an aqueous solution of a tertiary amine oxide which can dissolve cellulose in order to dissolve the cellulose on the surface, and then pressing the soaked fleece at an elevated temperature, after which the solution of the tertiary amine oxide is washed out of the pressed fleece.
• a tertiary amine oxide which can dissolve cellulose in order to dissolve the cellulose on the surface
• the invention also relates to a device for carrying out the method according to the invention, which device comprises: an opening for receiving precipitant and filaments, a channel which is connected to the opening and in which the filaments are guided, which device is characterized in that the channel opens into an acceleration area in which the filaments are accelerated with a precipitant which is introduced via a feed which opens into the acceleration area at a pressure which is higher than atmospheric pressure.
• the invention further relates to a spinning device for carrying out the amine oxide process according to the
• the invention also relates to the use of an injector which has: a channel in which freshly extruded cellulosic
• Filaments are guided an acceleration area, into which the channel opens, so that the filaments can be fed to the acceleration area, and a feed for precipitant, which feeds into the acceleration area, so that precipitant can be fed to the acceleration area, in the production of cellulosic filaments by the dry / wet spinning process, in which a solution of cellulose in an aqueous tertiary amine oxide is formed into filaments, which are drawn in an air gap and then brought into contact with precipitant.
• FIG. 1 shows in FIG. 1 the use according to the invention of an injector for dry / wet spinning of solutions of cellulose in a tertiary amine oxide.
• Figure 2 shows a preferred embodiment of the device according to the invention.
• 1 is 1 with a heatable (heating not darge sets) designated spinneret which C, is fed via the feed line 2 with spinning material 3, that hot cellulose solution at a temperature of about 100 ° C to 120 *.
• the pump 4 serves to meter the spinning mass and to set the pressure required for the extrusion.
• the filaments 5 extruded from the spinneret 1 via the spinning holes 16 are cooled with an inert gas 6, preferably air, which is directed via the gas nozzles 7 onto the filaments 5 leaving the spinneret 1.
• the filaments 5 are guided into the channel 9 of the injector 17 and finally reach an acceleration area 10 of the injector 17, in which the filaments come into contact with precipitant flowing rapidly downwards in the direction of the diffuser 11, as a result of which the cellulose is precipitated.
• the Filaments accelerated.
• the precipitant used for acceleration is pressed into the injector 17 via the feed 14. Due to the acceleration of the filaments in the direction of the diffuser 11, the filaments are drawn downward at a higher speed than they are supplied by the spinneret 1. This causes the filaments to stretch.
• the drawn filaments emerge from the injector 17 through the diffuser 11 and can be deposited, for example, on a sieve (not shown). The guidance of the filaments through the injector 17 is not shown in FIG. 1.
• the air gap extends from the bottom of the spinneret 1 to the end of the channel 9, i.e. to the mouth of the channel 9 in the acceleration range 10.
• the length of the channel 9 is not limited and can also be shorter than shown in FIG. 1.
• FIG. 2 shows a preferred embodiment of the device according to the invention.
• parts of the device which have already been described in FIG. 1 are given the same reference numbers.
• the filaments 5 extruded from the spinneret 1 enter a device which essentially has an injector part 18 on which a type of spinning funnel 19 is placed.
• the mechanical connection of the injector part 18 to the spinning funnel 19 can e.g. be made by screwing.
• the filaments 5 extruded from the spinneret 1 reach the precipitant 15 of the spinning funnel 19 via an air gap, which is defined by the distance of the underside of the spinneret 1 from the surface of the precipitating agent 15, are guided through the channel 9a and finally reach the Acceleration range 10 of the injector 18, in which the filaments flow from the fast downward direction towards the diffuser 11 Precipitating agents are accelerated.
• the precipitant used for acceleration is pressed into the injector 18 via the feed 14. Due to the acceleration of the filaments in the direction of the diffuser 11, the filaments are drawn downward at a higher speed than they are supplied by the spinneret 1. This causes the filaments to stretch in the air gap.
• the spinning funnel 19 there is a feed 12 for precipitant which is pumped into the cone 8 via the channel 13. Care must be taken that the amounts of precipitant which are fed to the spinning funnel 19 via the feeds 12 and 14 or discharged from the injector 18 via the diffuser 11 are matched to one another in such a way that the desired stretching is achieved in the air gap and at the same time a decrease in the liquid level 15 and thus an enlargement of the air gap is prevented.
• a spinnable cellulose solution with a cellulose content of 12% (NMMO: 77%; H 2 0: 11%) was prepared in a heatable and evacuable stirred kettle made from sulfite pulp and aqueous NMMO. This solution was extruded at 130 ° C from a spinneret with 888 holes (hole diameter: 80 / im) into filaments. The air gap was 22 mm.
• Precipitant was injected into feed 14 in an amount of 1008 l / hour.
• the precipitant speed in the acceleration area 10 at the exit of the channel 9a was approximately 378 m / minute, whereby a stretching or warping of 9.9 was achieved.
• a draw of 9.9 means that the filaments are drawn off at a speed which is 9.9 times the speed at which the filaments leave the spinneret and enter the air gap at which they are drawn.
• the stretching is therefore given by:
• the fibers produced had a titer of 1.30 dtex.
• Example 1 The process described in Example 1 was carried out, but the precipitant injection and precipitant speed given in the table below were selected and the stretching also given in the table was achieved.
• the filament strand produced in Example 2 was run onto a screen belt to form a nonwoven with a basis weight of 40 g / m 2 .
• the liquid permeability of this fleece was measured with a LISTER device according to the EDANA (European Disposables and Nonwovens Association) standard 150.2-93 (methodology: A certain amount (5 ml) of the test liquid (0.9% NaCl solution) is brought onto the fleece at a constant outlet speed (the time for the removal of this liquid through the fleece is measured electronically). The mean of 10 measurements was 1.47 see.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Artificial Filaments (AREA)
• Polysaccharides And Polysaccharide Derivatives (AREA)
• Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
• Nonwoven Fabrics (AREA)
• Chemical Or Physical Treatment Of Fibers (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)

Applications Claiming Priority (4)

Publications (2)

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Family Applications (1)

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• 1995
  • 1995-12-27 AT AT0210795A patent/AT402947B/de not_active IP Right Cessation
• 1996
  • 1996-12-20 AT AT96942981T patent/ATE176011T1/de not_active IP Right Cessation
  • 1996-12-20 ES ES96942981T patent/ES2129992T3/es not_active Expired - Lifetime
  • 1996-12-20 AU AU11857/97A patent/AU1185797A/en not_active Abandoned
  • 1996-12-20 EP EP96942981A patent/EP0811087B1/fr not_active Expired - Lifetime
  • 1996-12-20 JP JP9523913A patent/JPH11501371A/ja active Pending
  • 1996-12-20 WO PCT/AT1996/000260 patent/WO1997024476A1/fr not_active Ceased
  • 1996-12-20 DE DE59601184T patent/DE59601184D1/de not_active Expired - Fee Related
  • 1996-12-20 CA CA002213221A patent/CA2213221A1/fr not_active Abandoned
  • 1996-12-20 CN CN96193341.0A patent/CN1181788A/zh active Pending
  • 1996-12-20 BR BR9607047A patent/BR9607047A/pt not_active Application Discontinuation
• 1997
  • 1997-08-15 NO NO973763A patent/NO973763D0/no not_active Application Discontinuation

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