JP5900031B2 - Acrylic fiber manufacturing method and manufacturing apparatus thereof - Google Patents

Description

  The present invention relates to a manufacturing method and a manufacturing apparatus for obtaining acrylic fibers having high quality and excellent productivity.

  The demand for carbon fiber has been increasing for several years, and it is widely used for applications such as aircraft and sports, which require high functions, and general industrial applications such as civil engineering and construction. In order to meet these demands for expanding applications, it is necessary to reduce production costs and significantly increase production capacity. For this purpose, it is important to increase the productivity of acrylic yarns, which are precursors of carbon fibers. As a means for this, the number of single fibers constituting the yarns is increased to increase the total fineness of the yarns. It is most effective to improve productivity per equipment.

  In an ordinary carbon fiber precursor acrylic yarn manufacturing method, the yarn is guided and stretched until it is dried and densified after the spinning solution is led to a coagulation bath to obtain a coagulated yarn. The yarn is fed using a plurality of rollers. However, when the total fineness of the yarn is increased, with the current equipment premised on the processing of the regular tow, the distance between the adjacent weights on the roller becomes narrower, and interference between the yarns and fiber mixing occur. Occurring and causing single fiber damage, yarn breakage, fluffing, adhesion, and the like occur, resulting in a problem that the thread passage in the process is hindered. At the same time, fineness spots are generated by stretch spots between subsequent stretching processes, and the physical properties of the resulting carbon fibers are also lowered.

  In order to prevent this, it is necessary to lengthen each roller and widen the interval between adjacent weights. In that case, however, a large-scale facility modification including the drive unit is required, and the length of the roller is long. If the length is longer than this, it becomes difficult to handle tow yarn introduction and trouble handling, and a major problem remains in safety.

  In order to solve this problem, for example, in Japanese Patent Application Laid-Open No. 2007-291580 (Patent Document 1), a fluid is ejected from a slit opening provided in the width direction of the path along which the swollen swollen yarn travels. It has a yarn width control process for controlling the yarn width of the swollen yarn by providing converging properties to the yarn and by regulating plates provided on both sides of the path along which the swollen yarn travels. The distance between the left and right regulating plates in this yarn width control step is set to a width of 30% to 60% of the yarn width to be introduced, and any one of fluids such as water, liquid containing an oil agent, and air is ejected from the slit opening. It is described that the narrowness of the tow can be achieved while maintaining a uniform tow shape by imparting a focusing property.

JP 2007-291580 A

  According to the method described in Patent Document 1, the tow can be narrowed, but the widened tow traveling from the upstream of the process is set to 30% to 60% of the yarn width. By sharply narrowing the plate, the tow shape deteriorates, and it becomes easy to generate tow cracks and skew yarns, as well as single yarn breakage and tow breakage at the toe edge, and a high-quality carbon fiber precursor. There is a problem that a sufficient effect cannot be obtained in order to obtain a fiber yarn which is a body.

  In addition, when the tow is narrowed using the yarn width control device before the oil agent application step, the tow thickness increases compared to before the width of the tow is narrowed, and the excess oil solution impregnated in the yarn is guided. It is difficult to squeeze with a nip roll or the like, and the amount of moisture brought into the subsequent drying process increases, resulting in a problem that the drying efficiency is lowered and the manufacturing cost is increased.

  Further, when the oil solution is excessively adhered to the yarn and dried / densified in the subsequent drying process, the oil agent is likely to adhere to the yarn. There was a problem that thread breakage occurred.

  As a method of squeezing the acrylic fiber thread, the thread is brought into contact with a plurality of guides to remove the oil liquid impregnated in the thread, passed through a nip roller, or reversed to a plurality of rollers. There is a method of removing excess oil solution through the filter.

  However, with these methods, it is difficult to efficiently squeeze out moisture from the yarn for thick yarns and thick yarns. Therefore, fluff is likely to occur and there is a risk of winding. There is a problem that there is.

  The present invention is a carbon fiber precursor that prevents interference and mixing between adjacent yarns during production, has excellent process passability, and provides a high-quality and inexpensive carbon fiber with a large total fineness. An object of the present invention is to provide a method of manufacturing an acrylic yarn and a manufacturing apparatus thereof.

In the yarn width control step having a yarn width restriction portion for restricting the width of the acrylic fiber swelling yarn, which is the first basic configuration of the present invention, the same restriction width along the yarn traveling direction in the yarn width restriction portion A first yarn width restricting portion having a width and a second yarn width restricting portion whose width becomes narrower toward the outlet, and the width of the yarn traveling on the floor surface at the first yarn width restricting portion An acrylic fiber comprising: applying a liquid to the yarn, and regulating the width of the yarn so as to gradually decrease along the yarn traveling direction in a second yarn width regulating portion. The above-mentioned conventional problems are solved by this manufacturing method. It is preferable to use water or oil as the application liquid.

The method is an acrylic fiber manufacturing apparatus, which is a second basic configuration of the present invention, and includes a yarn width control step having a yarn width regulating portion on the travel path of the acrylic fiber swollen yarn. The yarn width regulating portion is set to be narrow toward the outlet, the first yarn width regulating portion having a first width regulating member that regulates and guides the widths of both side edges in the width direction with the same width. A second yarn width regulating portion having a second width regulating member is continuously arranged, and each of the first and second yarn width regulating portions includes a first floor surface and a first floor surface constituting each yarn running surface. Two floor surfaces, the first floor surface of the first yarn width regulating portion has an opening formed extending in the width direction, and a liquid ejecting means for ejecting liquid from the opening, The second yarn width regulating portion regulates the width between the left and right fiber width regulating surfaces so that the width gradually decreases along the running direction of the yarn. Comprising a second width regulating member for the inner, it is suitably carried out by the manufacturing apparatus of the acrylic fiber.

The width between the restriction width of the first yarn width restriction portion and the inlet width of the second yarn width restriction portion is Amm, the exit width of the second yarn width restriction portion is Bmm, and the yarn width restriction surface in the second yarn width restriction portion It is preferable that A, B, and C satisfy the following formulas (1) and (2) when the length in the fiber running direction is Cmm.
1.5 × B ≦ A ≦ 4.0 × B (1)
3.0 × A ≦ C ≦ 15.0 × A (2)

Moreover, it is preferable that the regulation width of the first width regulating member is constant, and the first and second floor surfaces of the first and second yarn width regulating portions are constituted by a single member, or the first And the 1st and 2nd floor surfaces of the 2nd yarn width regulation part may be constituted from exclusive members, respectively. More preferably, it is preferable that the first yarn width regulating portion and the second yarn width regulating portion are continuously arranged.

  More preferably, in the present invention, an air ejection nozzle is disposed after the yarn width control step, an air ejection port provided in the air ejection nozzle is brought into contact with the yarn, and is perpendicular to the direction of travel of the yarn. The problem can be solved by ejecting the pressurized gas in a state of contacting the yarn from the direction. The jetting speed of the pressurized gas at this time is preferably in the range of 0.3 m / second to 80 m / second, more preferably 5 m / second to 60 m / second, and more preferably 10 m / second to 20 m / second.

  According to the present invention, when an acrylic yarn is manufactured with an increased total fineness, a step of applying a liquid to a flat yarn made of a swollen yarn of acrylic fiber, and the running of the yarn immediately thereafter The yarn is passed through first and second yarn width regulating portions provided on the floor surface of the travel path so that the interval gradually decreases along the direction, and the first and second yarn width regulating portions are passed. By rubbing the section and the first and second floor surfaces, and providing a yarn width control step for controlling the yarn width of the swollen yarn, without intentionally expanding the conventional equipment, Interference and fiber mixing are prevented, and the process passability is excellent, so that there is an effect that a high-quality and inexpensive carbon fiber without fluff can be obtained.

  The yarn width control step and the air ejection nozzle are preferably arranged before entering some stretching devices that are passed after washing with water, and the stretching step is performed after passing through the yarn width control step and the air ejection nozzle in the present invention. By arranging the yarn, the yarn can be uniformly drawn in the drawing step, and the resulting precursor yarn can have a variation rate of fineness unevenness in the longitudinal direction of 1% or less. When the liquid ejected from the opening formed in the first yarn width regulating portion is made into an oil agent-containing liquid material, the oil agent is uniformly applied to the tow, and the excessive oil agent liquid impregnated in the yarn is uniformly distributed. It is possible to reduce the oil adhesion spot (CV value) in the length direction of the precursor yarn to 6% or less, and drastically reduce the fluff and yarn breakage of the single fiber in the subsequent steps. be able to.

It is a schematic side view which shows the example of an arrangement | positioning aspect of the yarn width | variety control process in the manufacturing apparatus of the acrylic fiber of this invention. It is a top view which shows roughly typical embodiment of the yarn width | variety control part in this invention. It is a top view which shows schematically other embodiment of the yarn width | variety control part in this invention. It is a top view which shows schematically other embodiment of the yarn width | variety control part in this invention. It is a top view which shows schematically other embodiment of the yarn width | variety control part in this invention. It is a top view which shows schematically other embodiment of the yarn width | variety control part in this invention. It is a top view which shows schematically other embodiment of the yarn width | variety control part in this invention. It is a top view which shows roughly the yarn width control part which is a comparative example with this invention. It is a top view which shows roughly embodiment of the air ejection nozzle and air ejection port in this invention.

Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.
The acrylonitrile-based polymer used in the production method of the present invention is not particularly limited as long as it is used for a normal carbon fiber precursor acrylonitrile fiber, and is a homopolymer or copolymer of acrylonitrile, or of these polymers. Mixed polymers can be used. Monomers that can be copolymerized with acrylonitrile include (meth) acrylic esters such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and hexyl (meth) acrylate. Vinyl halides such as vinylidene chloride; maleic imide, phenylmaleimide, (meth) acrylamide, styrene, α-methylstyrene, vinyl acetate; styrene sulfonic acid soda, acrylic sulfonic acid soda, β-styrene sulfonic acid soda, meta Polymerizable unsaturated monomers containing a sulfone group such as sodium allyl sulfonate; polymerizable unsaturated monomers containing a pyridine group such as 2-vinylpyridine and 2-methyl-5-vinylpyridine However, it is not limited to these.

Examples of the method for polymerizing the monomer mixture include, but are not limited to, redox polymerization in an aqueous solution, suspension polymerization in a heterogeneous system, and emulsion polymerization using a dispersant.
In the method for producing acrylic fibers according to the present invention, first, these acrylonitrile polymers are dissolved in a solvent such as dimethylacetamide, dimethylsulfoxide, dimethylformamide, nitric acid, or aqueous rhodium soda solution to obtain a spinning dope.

Next, using a spinneret, the spinning dope is discharged into a coagulation bath (wet spinning) or once discharged into the air and then guided to the coagulation bath (dry-wet spinning) to obtain a coagulated yarn. For the coagulation bath, an aqueous solution containing a solvent used for the spinning dope is generally used.
The coagulated yarn in this state contains water in the fiber and is in a swollen state until it is dried and densified in a later step. In a normal production method, a coagulated yarn is taken out from a coagulation bath by a godet roller, and then subjected to necessary steps such as washing, stretching, and application of an oil agent, followed by drying and densification to obtain a precursor fiber for carbon fiber. .

  As shown in FIG. 1, the yarn width control step FWC in the acrylic fiber manufacturing method according to the present invention is adjacent to the upstream side of the second and third roll boxes RB2 and RB3 arranged in the wet drawing step, for example. Arranged. In the yarn width control step FWC, a yarn width regulating portion that regulates and guides the width of the expanded and flatly swollen yarn running through the first roll box RB1 disposed in the previous step. FWR is provided. The yarn width regulating portion FWR includes first and second yarn width regulating portions WR1 and WR2. The first and second yarn width regulating portions WR1 and WR2 are first and second floor surfaces (yarn running surfaces) 1. , 2 and first and second width regulating members 3, 4; 5, 6, each of which consists of a pair of left and right standing on the first and second floor surfaces 1, 2.

  The yarn traveling on the fiber traveling path travels so as to rub against the regulating surfaces of the first and second floor surfaces 1 and 2 and the first and second width regulating members 3, 4; To do. When the yarn travels on each regulation surface, it is necessary to make each regulation surface a smooth surface in order to prevent the occurrence of fluffing of single fibers and yarn breakage. Therefore, as a material used for the first and second floor surfaces 1 and 2 and the first and second width regulating members 3, 4; 5, 6, a stainless steel material that hardly corrodes and can easily form a smooth surface is used. It is desirable to use it, and it is preferable to apply plating to at least the regulating surface of the stainless steel that comes into contact with the yarn.

The yarn narrowed in the yarn width control step FWC has a large thickness, and it is difficult to uniformly remove moisture (or oil) present in the yarn with a conventional guide or nip roll. Therefore, it is preferable to install the air ejection nozzle 10 so as to cross the yarn traveling path at a right angle after the yarn width control step FWC as shown in FIG.
When the yarn width control step FWC and the air ejection nozzle 10 are arranged in front of the drawing tank, the residual solvent contained in the yarn is removed by the air ejection nozzle, so that the amount of residual solvent brought into the next step As a result, the cleaning load is reduced.

Moreover, when the yarn width control process FWC and the air ejection nozzle 10 are arranged as an oil bath, the oil liquid contained in the tow is removed by the air ejection nozzle 10, so that the oil liquid to the next process (drying process) ( The amount of oil (mixed liquid of oil and water) is reduced, so the drying load is reduced. Furthermore, the effect of reducing the uneven adhesion of the oil is obtained by removing the oil that is unevenly distributed in the tow. .

By arranging the air ejection nozzles 10 installed after the yarn width control step FWC in multiple stages, the effect can be obtained more easily. However, it is preferable to set the optimum number of steps in consideration of the installation space, the capital investment cost, the running cost, and the damage to the tow due to the air ejection.
Usually, a sufficient effect can be obtained by providing one or two stages.

It is preferable that the air ejection port 11 provided in the air ejection nozzle 10 is ejected in a direction perpendicular to the traveling direction of the yarn. Pressurized gas jetted in the vertical direction can penetrate the yarn efficiently, and it is possible to efficiently remove excess liquid impregnated in the yarn and oil liquid unevenly distributed in the yarn. Become.
The ejection direction is preferably from the top to the bottom from the point of scattering of liquid or oil and the point of most adhesion.

In addition, it is important that the air ejection port 11 of the air ejection nozzle 10 is brought into contact with the traveling yarn and the pressurized gas is ejected in a state where there is no space (gap) between the air ejection port 11 and the yarn. is there. By bringing the air jets into contact with the surface of the yarn, the effect of the pressurized gas penetrating the yarn is further increased, and the excess liquid impregnated in the yarn and the oil liquid unevenly distributed in the yarn are efficiently removed. It becomes possible to do.
Conversely, when there is a distance (space) between the air jet outlet and the running yarn (when non-contact processing is performed), the yarn jets out due to the air jet output, and the air penetration effect is reduced. It becomes difficult to obtain the effects of the present invention. In addition, the tow is disturbed by the shaking of the tow, causing single yarn breakage or yarn breakage.

The material of the air ejection nozzle 10 and the air ejection port 11 is not particularly limited, but it is desirable to use a stainless steel material that is easy to form a smooth surface so as not to cause damage due to contact resistance with the running yarn, Furthermore, it is preferable to apply plating to at least the surface of the stainless steel that contacts the yarn.
FIG. 9 shows an example of an air ejection nozzle 10 and air ejection ports 11 (a) to (e) formed in the air ejection nozzle 10 and having various shapes and arrangements. 11 (a) to (c) in the figure is composed of one or more slits in which the air ejection port extends in the nozzle length direction, and the air ejection port 11 (a) in the same figure is formed from a single slit, The air jets 11 (b) and 11 (c) in the figure are examples in which two and three slits are formed in parallel. On the other hand, the air jets 11 (d) and 11 (e) in the figure are composed of a large number of small holes arranged along the length direction of the nozzle, and the air jets 11 (d) in the figure are An example is shown in which the air ejection nozzles 10 are arranged in two rows parallel to the length direction and arranged in a staggered manner. Moreover, the air ejection port 11 (e) in the figure shows an example in which three rows of small holes parallel to the length direction of the air ejection nozzle 10 are arranged in a staggered manner.

  As described above, the shape of the air ejection port 11 opened to the air ejection nozzle 10 is various, such as a porous type and a slit type, and is not particularly limited, but the air penetrates uniformly in the yarn width direction. It is preferable that openings continuously exist in the width direction of the yarn.

The tension of the tow when air is ejected is not particularly limited, but a great effect can be obtained by treating the tension of the yarn in the range of 40 cN / 1000 dtex to 500 cN / 1000 dtex.
If the tension of the yarn is 40 cN / 1000 dtex or less, the yarn is shaken by the air jet output, the air penetration force is weakened, and it is difficult to obtain the liquid removing effect. On the other hand, when the tension of the yarn is 500 cN / 1000 dtex or more, air cannot penetrate through the yarn, and it is difficult to obtain a liquid removing effect. Further, damage due to contact resistance with the air ejection nozzle 10 increases, which may cause thread breakage and fluff.

  The ejection speed of the pressurized gas ejected from the air ejection nozzle 10 can be selected appropriately depending on the yarn tension, installation location, number of yarn components, and fineness. It is preferably from 40 m / sec to 40 m / sec, and if it is 0.5 m / sec or less, it is difficult to obtain a liquid removing effect by air, and if it is 40 m / sec or more, thread breakage or fluff may be caused.

  According to the first embodiment of the present invention shown in FIG. 2, the first width regulating members 3 and 4 of the first yarn width regulating portion WR1 are erected in parallel on the first floor surface 1 along the yarn running direction. The first floor surface 1 is formed with a slit-like opening 7 extending perpendicular to the yarn traveling direction. From this opening 7, as shown in FIG. 1, liquids, such as the oil agent discharged from the ejection pump 8, and ion-exchange water, are ejected and a liquid is provided to a thread | yarn. Is the regulated width dimension A (mm) of the yarn by the first width regulating members 3 and 4 when traveling through the first yarn width regulating portion WR1 equal to the width of the widened yarn when fed from the previous process? The width is set slightly narrower than its width.

  At this time, as shown in FIG. 2, the second width regulating members 5 and 6 disposed in the second yarn width regulating portion WR2 in the first embodiment serve as the width of the first width regulating members 3 and 4 as shown in FIG. It is equal to the dimension A (mm), and the width dimension B (mm) of the outlet is set narrower than the width dimension A of the inlet. That is, the width dimension (left-right distance) of the second width regulating members 5 and 6 is gradually narrowed from the entrance to the exit of the yarn. Therefore, the yarn travels by rubbing the right and left side edges thereof along the second width regulating members 5 and 6 with a required distance C (mm), and the yarn width is regulated so as to gradually narrow during that time. .

  In the first yarn width regulating portion WR1 in the yarn width control step FWC, the swollen yarn is fed in the state in which the tow width is expanded most and the thickness variation of the tow is reduced. By applying a liquid from the slit-like opening 7 of the floor surface 1, the residual solvent and water (ion-exchanged water) or water (ion-exchanged water) and oil agent at the single yarn level in the swollen yarn are replaced. Immediately thereafter, the yarn is introduced onto the second floor surface 2 of the second yarn width regulating portion WR2, and the pair of left and right second width regulating members 5 and 6 provided on the second floor surface 2, It is regulated so that the interval gradually decreases along the running direction of the yarn. By this regulation, it is possible to obtain a uniform tow shape without cracking or skewing of the yarn, and without breakage or breakage of the single yarn at the edge portion of the tow yarn. Further, since the liquid present inside the tow is squeezed out in the process of narrowing the tow width, the liquid replacement efficiency is further improved.

  The material of the regulating member and the bottom member is not particularly limited, but is preferably a stainless material that is not easily corroded, and further subjected to plating so as not to cause damage due to contact resistance between the swollen yarn and the regulating member and the bottom member. preferable.

The second width regulating members 5 and 6 run by rubbing the width A of the yarn inlet, the width B of the yarn outlet and the left and right edges of the yarn along the second width regulating members 5 and 6. The distance C is set so as to satisfy the following formulas (1) and (2), and either water or an oil-containing liquid material is applied to the swollen yarn from the opening of the first yarn width regulating portion WR1. When converging is imparted by jetting, it becomes possible to narrow the width while stably maintaining a more uniform yarn form.
1.5 × B ≦ A ≦ 4.0 × B (1)
3.0 × A ≦ C ≦ 15.0 × A (2)

If the width separation dimension A at the yarn introduction end of the pair of left and right second width regulating members 5 and 6 is smaller than 1.5 times the width dimension B of the yarn lead-out end, the single width at the edge portion of the tow yarn will be reduced. If thread breakage or tow breakage occurs, and if it exceeds 4.0 times, it is difficult to control the width while maintaining a uniform yarn form.
Further, when each rubbing distance C between the second width regulating members 5 and 6 is shorter than 3.0 times the interval (width) A between the introduction ends, the yarn is abruptly narrowed, and the uniform yarn It is difficult to control the width while maintaining the form, and if it exceeds 15.0 times, it is difficult to obtain the effect of controlling the fiber width.

Next, a method for controlling the width of the yarn in the production process of the acrylic yarn as the carbon fiber precursor according to the embodiment of the present invention will be specifically described with reference to the drawings.
FIG. 1 schematically shows a part of an acrylic fiber manufacturing apparatus according to the present invention and a manufacturing method thereof. The swollen yarns of acrylic fibers that have been subjected to a washing process in the previous step and run in parallel in units of weight are introduced into the yarn width control step FWC and the air ejection nozzle 10 in the present invention. At this time, since the swollen yarn is passed through a large number of rolls, the yarn width is widened and flattened. The flat yarn T introduced into the first yarn width regulating portion WR1 of the yarn width control step FWC is extended on the first floor 1 perpendicular to the traveling direction of the yarn T as shown in FIG. The liquid is directly ejected from the plurality of liquid ejection openings 7 toward the running surface of the yarn T, and the residual solvent and water (ion-exchanged water) or water (ion-exchanged water) at the single yarn level in the swollen yarn The replacement water) and the oil agent are replaced.

Subsequently, immediately between the pair of left and right second width regulating members 5 and 6 provided on the second floor 2 so that the interval gradually decreases along the traveling direction of the yarn T immediately after the second floor. The yarn T is caused to travel along the surface 2 and the pair of left and right second width regulating members 5 and 6 while being rubbed to uniformly narrow the yarn width.
Ejection amount of the liquid is 0.5m ³ /hr~1.5m ³ / hr against the yarn T per weight, preferably 0.8m ³ /hr~1.2m ³ / hr. Is less than the amount of ejection is 0.5 m ³ / hr, and insufficient penetration by water flow, converging yarn T (narrowing) can not be obtained, when it exceeds 1.5 m ³ / hr, through the reverse The force increases, skewing of the tows and tow cracks occur, and in the worst case, there is a possibility of causing single yarn breakage. By adjusting the flow rate of the ejected fluid, the opening area of the opening, and the distance between the width regulating members on both sides, the width of the yarn T can be controlled uniformly.

  In the present invention, the total fineness of the precursor fiber finally obtained by drying and densification is not particularly limited, and can be applied over a wide range. In particular, the effect of controlling the yarn width is 22,000 dtex. (2.2 kg / km) or more, preferably 22,000 dtex or more and 99,000 dtex or less.

  The spinning device includes a first roll box RB1, a second roll box RB2, a wet heat stretching device, and a third roll box RB3. In the embodiment shown in FIGS. The control process FWC and the air ejection nozzle 10 are provided between the first roll box RB1 and the second roll box RB2. Either the water or the oil-containing liquid material is sent to the opening 7 formed in the first floor surface 1 by the ejection pump 8. Reference numeral 9 denotes a cleaning tank. Thus, it is preferable to arrange the yarn width control step FWC in front of several stretching devices after washing with water. As described above, in the form of the uniform yarn T in which the yarn width is controlled, the variation rate (CV) of the fineness unevenness in the longitudinal direction of the precursor yarn is 1% or less even after being drawn by the drawing device. The carbon fiber precursor acrylic yarn is preferable.

  In addition, the yarn width control step in the present invention is arranged before drying and densification after washing and stretching, and when the liquid supplied to the opening is an oil agent, it is also used as a uniform adhesion device for the oil agent The variation rate (CV) of the oil agent adhesion spot in the longitudinal direction of the precursor yarn is 6% or less, which is preferable as the carbon fiber precursor acrylic yarn.

FIGS. 3-6 has shown other embodiment of the 1st and 2nd thread width control part WR1, WR2 distribute | arranged to the thread width control process FWC in this invention.
According to the embodiment shown in FIGS. 3 to 5, the first yarn width restricting portion WR1 and the second yarn width restricting portion WR2 are continuously arranged as in the first embodiment shown in FIG. . That is, the first and second floor surfaces 1 and 2 are integrally formed from a single member, and the first and second width regulating members 3, 4; There is no difference from the embodiment. In the embodiment shown in FIG. 3, the opening 7 formed in the first floor surface 1 of the first yarn width restricting portion WR1 is different from the first embodiment in that it includes a single slit-like opening. According to the embodiment shown in FIG. 4, the opening 7 formed in the first yarn width restricting portion WR <b> 1 is not a slit shape but is composed of a plurality of perfectly circular holes.

The embodiment shown in FIG. 6 is greatly different from the first embodiment in that the first yarn width regulating portion WR1 and the second yarn width regulating portion WR2 are spaced apart. That is, the first floor surface 1 and the second floor surface 2 are arranged with a predetermined distance therebetween. The first width regulating members 3 and 4 and the second width regulating members 5 and 6 may be separated from each other or made continuous. In the embodiment shown in FIG. 7, wide first and second floor surfaces 1 and 2 made of a single member are arranged on the first and second yarn width regulating portions WR1 and WR2 in the yarn width control step FWC in the present invention. On the first and second floor surfaces 1 and 2, a plurality of first and second width regulating members 3, 4; 5, 6 are arranged in parallel in the yarn running direction in units of weight. An example is shown.
In the present invention, these embodiments have no significant difference in function and effect, but are appropriately adopted based on the total fineness of the yarn, the single fiber fineness, or differences in processing and processing conditions in the preceding and following steps. is there.

As described above, in the present invention, liquid is ejected from the fluid ejection opening 7 provided in the width direction of the first floor surface 1 to the traveling yarn T composed of a flat swollen yarn in a swollen state. After that, the second width regulating members 5 and 6 for controlling the yarn width are provided so that the regulation widths of the second width regulating members 5 and 6 on both sides of the path along which the swollen yarn travels are gradually narrowed toward the downstream of the process. By passing between 6, the entanglement between the single fibers and the yarn width are uniformly controlled, and the tow yarn form can be made uniform.
Further, after the yarn width control step, an air ejection nozzle 10 is disposed, and a pressurized gas is applied in a direction perpendicular to the yarn traveling direction with the air ejection port 11 provided in the air ejection nozzle 10 in contact with the yarn. , And excess liquid impregnated in the yarn can be removed.

As a result, interference between adjacent weights and fiber mixing can be prevented, and a high-quality carbon fiber precursor acrylic yarn excellent in process passability can be manufactured at low cost.
The carbon fiber precursor acrylic yarn obtained by the present invention can be converted into high-grade carbon fiber through a firing process such as flameproofing treatment and carbonization treatment.

Hereinafter, typical examples and comparative examples of the present invention will be described more specifically with reference to the drawings.
[Example 1]
Acrylonitrile, acrylamide and methacrylic acid are copolymerized by aqueous suspension polymerization in the presence of ammonium persulfate-ammonium hydrogen sulfite and iron sulfate, and consist of acrylonitrile units / acrylamide / methacrylic acid units = 96/3/1 (mass ratio). Acrylonitrile polymer was obtained. This acrylonitrile-based polymer was dissolved in dimethylacetamide to prepare a 21% by mass spinning solution.

This spinning dope is discharged through a spinneret having a pore size of 50,000 and a pore diameter of 45 μm into a coagulation bath composed of an aqueous dimethylacetamide solution having a concentration of 60% by mass and a temperature of 35 ° C. to obtain a coagulated yarn. It was taken up at a take-up speed of 39 times. Next, the fiber is stretched 5.4 times at the same time as being washed with water, led to the first oil bath of the aminosilicone oil agent prepared to 1.5% by mass, and the first oil agent is given, and several guides are used. After squeezing once, the second oil agent was applied in the second oil bath of aminosilicone oil agent prepared to 1.5% by mass. This fiber was dried using a hot roll, and dry heat secondary stretching between the hot rolls was performed 1.3 times. Thereafter, the moisture content of the fibers was adjusted with a touch roll, and carbon fiber precursor fibers having a single fiber fineness of 1.2 dtex were collected with a winder.

  The yarn width control step FWC shown in FIG. 6 is provided before the wet heat drawing step, a plurality of parallel running swollen yarns are introduced into the yarn width control step FWC, converging is given, and a predetermined yarn width is further provided. Was uniformly controlled.

  In this embodiment, ion-exchanged water (DI water) is used as the water, and the water is directly jetted onto a flat yarn composed of a plurality of swollen yarns running in parallel from the opening of the first floor surface 1. Was applied and the yarn width was controlled, leading to the subsequent drawing process.

The apparatus and processing conditions in the yarn width control step FWC used in this embodiment shown in FIGS. 1, 2 and 5 are the restriction width of the first width restriction members 3 and 4 and the second width restriction members 5 and 6. The inlet width A is 40 mm, the downstream width B of the second width restricting members 5 and 6 is 12 mm, the contact distance C of the second width restricting members 5 and 6 is 400 mm, the amount of jetted water is 1 m ³ / hr, and the yarn width The tow width when introduced into the control step FWC was 40 mm. Spinning could be performed stably without problems such as mixing with adjacent weights and interference, and there were no tow forms running through the process and no defects such as tow cracking and crossing. Table 1 shows the evaluation results of the precursor fibers obtained from the evaluation results of the manufacturing process.

  In Examples 2 to 4 below, experiments were performed in the same manner as in Example 1 except that the specification of the yarn width control device was set as follows. In these Examples 2 to 4, the regulation width of the first width regulating members 3 and 4 is constant and is matched with the inlet width of the second width regulating members 5 and 6. The width at this time is A (mm).

[Example 2]
The width A of the upstream end of the second width regulating members 5 and 6 is 40 mm, the width B of the downstream end is 25 mm, the contact distance C of the second width regulating members 5 and 6 is 400 mm, and DI water is used as the jet liquid. It was.
As shown in Table 1, spinning can be performed stably without problems such as fiber mixing with adjacent weights and interference, and the tow form running in the process was good with no defects such as tow cracking and oblique crossing.

Example 3
A yarn width control device was provided instead of the oil bath, and an oil agent was applied while uniformly controlling a plurality of parallel swollen yarns so as to have a predetermined yarn width.
As the applied liquid, the yarn inlet width A at the upstream end of the second width regulating members 5 and 6 is 30 mm, the yarn outlet width B at the downstream end is 17 mm, and the contact distance C between the second width regulating members 5 and 6 is 400 mm. When the oil was used and introduced into the yarn width controller, the yarn width was 30 mm. Even in this embodiment, as shown in Table 1, stable spinning can be performed without troubles such as mixing with adjacent weights and interference, and the tow form that runs the process is also good without defects such as tow cracking and oblique crossing. Met.

Example 4
An experiment was conducted in the same manner as in Example 3 by using the yarn width control device shown in FIG.
The second width regulating members 5 and 6 have an upstream end yarn inlet width A of 30 mm, a downstream end yarn outlet width B of 17 mm, and a second width regulating member (regulator plate) contact distance C of 400 mm. In this case, an oil was used, and the width of the yarn when introduced into the yarn width control device was 30 mm. Even in this example, as in Example 3, the tow form that travels through the process was satisfactory with no defects such as toe cracks and crossing.

Example 5
Experiments were conducted in the same manner as in Example 3 using the yarn width control device shown in FIGS. 1, 2, and 5. The second width regulating members 5 and 6 have a yarn inlet width A of 40 mm, a downstream yarn outlet width B of 12 mm, and a contact distance C of the second width regulating members 5 and 6 of 400 mm. Similarly, an oil agent was used as the application liquid, and the width of the yarn when introduced into the yarn width control device was 30 mm.

  Further, an air ejection nozzle 10 is disposed after the yarn width control device, the air ejection port 11 (e) is brought into contact with the yarn in a direction perpendicular to the traveling direction of the yarn, and pressurized air is ejected at a speed of 15 m / Erupted in seconds. As shown in Table 1, it was possible to perform stable spinning without any troubles such as fiber mixing with adjacent weights and interference, and the tow form traveling in the process was good without defects such as tow cracking and oblique crossing. In particular, the adhesion spot of the oil agent was remarkably low as compared with other examples.

Example 6
Implemented except that the air ejection nozzle 10 is arranged after the yarn width control device, and the pressurized air is ejected at an ejection speed of 15 m / sec with a distance of 5 cm between the yarn and the air ejection port 11 (e). The experiment was conducted in the same manner as in Example 5.
The processability and quality of the yarn were good.

Example 7
An air ejection nozzle 10 is disposed after the yarn width control device, the air ejection port 11 (e) is brought into contact with the yarn from a direction perpendicular to the traveling direction of the yarn, and pressurized air is ejected at a speed of 0.3 m / second. The experiment was performed in the same manner as in Example 5 except that the ejection was performed in seconds.
The processability and quality of the yarn were good.

Example 8
An air ejection nozzle 10 is arranged after the yarn width control device, the air ejection port 11 (e) is brought into contact with the yarn from a direction perpendicular to the traveling direction of the yarn, and pressurized air is ejected at an ejection speed of 60 m / sec. The experiment was performed in the same manner as in Example 5 except that the ejection was performed.
The processability and quality of the yarn were good.

[Comparative Example 1]
An experiment was conducted in the same manner as in Example 3 except that the yarn width control device shown in FIG. 8 was used. FIG. 8 is a plan view of a yarn width control device showing an example of a conventional yarn width control device used in the first comparative example.
The restriction width of the yarn width restriction portion in this comparative example 1 is uniform from the yarn introduction port to the lead-out port, the width is 17 mm, the length of the yarn width restriction member is 400 mm, and the oil agent is used as the application liquid. The width of the yarn before being used and introduced into the yarn width control device was 30 mm.

  As can be understood from Table 1, the number of single fibers bonded was 4, and there were many mixed fibers. Further, the generation of fluff was observed at the edge of the tow, and the toe was cut off. Further, the fiber spots were 1.8% and the oil agent adhesion spots were 13%.

1, 2 First and second floor surfaces 3, 4 First width regulating members 5, 6 Second width regulating member 7 Opening 8 Jet pump 9 Cleaning tank 10 Air jet nozzles 11, 11 (a) to 11 (e) Air Spout FWC Yarn width control step FWR Yarn width regulating portions RB1 to RB3 First to third roll boxes WR1, WR1 First and second yarn width regulating portions T Yarn

Claims (14)

In a yarn width control step having a yarn width restricting portion for restricting the width of the acrylic fiber swelling yarn, the yarn width restricting portion includes a first yarn width restricting portion having the same restricting width along the yarn traveling direction and an outlet. Continuously arranging the second yarn width regulating portion whose width becomes narrower toward the
The first yarn width regulating part regulates the width of the yarn traveling on the floor surface, the liquid is applied to the yarn, and the second yarn width regulating part sets the width of the yarn to the yarn. Restricting it to gradually decrease along the direction of travel,
A method for producing an acrylic fiber comprising:   The air jet nozzle is disposed after the yarn width control step, and the pressurized gas is jetted onto the yarn in a state where the air jet port provided in the air jet nozzle and the yarn are in contact with each other. The manufacturing method of the acrylic fiber of description.   The method for producing an acrylic fiber according to claim 2, wherein an ejection speed of the pressurized gas ejected from the air ejection port is 0.3 m / second to 80 m / second. The first yarn width regulating portion regulates the regulation width of the yarn to be constant, and the application of the liquid is performed by ejecting liquid from an opening provided on a floor surface of a traveling path;
The manufacturing method of the acrylic fiber as described in any one of Claims 1-3 which comprises these. The width of the first yarn width regulating portion and the width of the inlet width of the second yarn width regulating portion are Amm, the outlet width of the second yarn width regulating portion is Bmm, and the yarn width regulating surface of the second yarn width regulating portion; When the contact distance in the yarn running direction is Cmm, the A, B, and C satisfy the following formulas (1) and (2). The manufacturing method of acrylic fiber as described in any one of.
1.5 × B ≦ A ≦ 4.0 × B (1)
3.0 × A ≦ C ≦ 15.0 × A (2)   The method for producing acrylic fiber according to any one of claims 1 to 5, comprising using water as the applied liquid.   The method for producing acrylic fiber according to any one of claims 1 to 5, comprising using an oil as the applied liquid. An acrylic fiber manufacturing apparatus in which a yarn width control step having a yarn width regulating portion is arranged on a travel path of a swollen yarn of acrylic fiber,
The yarn width restricting portion includes a first yarn width restricting portion having a first width restricting member for restricting and guiding the widths of both side edges in the width direction of the yarn with the same width, and a narrow width toward the outlet. And a second yarn width regulating portion having two width regulating members,
Each of the first and second yarn width regulating portions has a first floor surface and a second floor surface constituting each yarn running surface,
The first floor surface of the first yarn width regulating portion has an opening formed extending in the width direction, and a liquid ejecting means for ejecting liquid from the opening,
The second yarn width restricting portion includes a second width restricting member that restricts and guides the width between the left and right fiber width restricting surfaces so as to gradually narrow along the running direction of the yarn.
Acrylic fiber manufacturing equipment.   9. The apparatus for producing acrylic fiber according to claim 8, further comprising an air ejection nozzle that ejects pressurized gas in a direction perpendicular to the traveling direction of the yarn downstream from the yarn width regulating device. The acrylic fiber manufacturing apparatus according to claim 8 or 9, wherein a restriction width of the first width restriction member is constant.   The acrylic fiber manufacturing apparatus according to any one of claims 8 to 10, wherein the first and second floor surfaces of the first and second yarn width regulating portions are formed of a single member.   The acrylic fiber manufacturing apparatus according to any one of claims 8 to 11, wherein the first and second floor surfaces of the first and second yarn width regulating portions are each configured by a dedicated member.   The acrylic fiber manufacturing apparatus according to any one of claims 8 to 12, wherein the first yarn width regulating portion and the second yarn width regulating portion are continuously arranged.   The acrylic fiber manufacturing apparatus according to any one of claims 8 to 12, wherein the first yarn width regulating portion and the second yarn width regulating portion are arranged apart from each other.

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