JP2019073827A - Melt-spinning apparatus and method for manufacturing fiber sheet using the same - Google Patents

Abstract

To provide a melt-spinning apparatus capable of manufacturing, with high productivity, a fiber sheet having a uniform basis weight and formed of fine fibers.SOLUTION: A melt-spinning apparatus 10 comprises a molten resin supply device 20, a spinning unit 30 and a connection member 40. The connection member 40 comprises a first member 41 formed of a heat-resistant material, having a convex part 41P on a non-opposing surface 41R to the molten resin supply device 20, and a second member 42 formed of the heat-resistant material, having a concave part 42P into which the convex part 41P can be inserted on a non-opposing surface 42R to the spinning unit 30. The first member 41 has a first through-hole 41H which passes through an apex of the convex part 41P and penetrates the first member 41. The second member 42 has a second through-hole 42H which passes through a bottom of the concave part 42P and penetrates the second member 42. The second member 42 is supported by the apex of the convex part 41P of the first member 41, and thus the second member 42 is inclined relative to the first member 41 while a communicating state of the first through-hole 41H and the second through-hole 42H is maintained.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a melt spinning apparatus and a method of producing a fiber sheet using the same.

  Melt spinning is a method in which a resin as a raw material of fibers is melted, extruded into air, and solidified by cooling to form fibers, and as a method of forming fine fibers, for example, hot air is applied to the extruded molten resin. The melt-blown method etc. which are applied and refined are performed. As other melt spinning methods, a high voltage is applied to charge the molten resin, and the charged molten resin is drawn by coulomb force, so that the melt electrospinning method of forming fibers with a thin fiber diameter is relatively simple. And it attracts attention as a manufacturing method with high productivity. For example, Patent Document 1 proposes a nanofiber generating device in which a plurality of spinning units are arranged for the purpose of mass production of fibers by a melt spinning method.

  In the melt spinning method, the basis weight distribution of the fiber sheet may vary depending on the discharge direction of the discharged molten resin. Therefore, controlling the discharge direction of the molten resin is one of the important factors in terms of improving the quality of the obtained fiber sheet. Although there is no direct relationship with the melt spinning method, as one of the mechanisms for changing the direction of the fluid, Patent Document 2 connects the connected pipes at an arbitrary angle to adjust the flow path direction. The concave spherical receiving surface and the spherical convex portion of the elastic member respectively provided on the two members having the plastic covering on the inner surface of the circulating metal pipe and the spherical convex portion on the concave spherical receiving surface Pipe joints capable of swinging movement have been proposed. Patent Document 3 proposes, for the purpose of adjusting the flow path direction, a direction changing nozzle which changes the direction of a resin flow path by combining divided block bodies having curved grooves.

Unexamined-Japanese-Patent No. 2016-216871 Japanese Patent Application Laid-Open No. 11-304065 Japanese Patent Application Publication No. 2003-025408

  When the pipe joint described in Patent Document 2 is adopted for the melt electrospinning method, the flow direction of the molten resin can be adjusted, but it is caused by having a plastic member at the contact portion of the molten resin. Since the plastic component contained in the member is eluted into the molten resin and may be mixed into the fiber and the fiber sheet as an impurity component, a problem arises from the viewpoint of fiber quality. In addition, the elastic member made of synthetic rubber or the like is melted and decomposed by heat, which causes a problem that the sealability is impaired. Since the direction change nozzle described in Patent Document 3 does not have a slidable structure, it is not easy to appropriately change the flow channel direction according to the change in basis weight of the manufactured fiber.

  Therefore, an object of the present invention is to provide a melt-spinning apparatus having a reduced fiber basis weight variation during melt-spinning, and a method of producing a fiber sheet using the same.

  The present invention is a melt spinning apparatus comprising a molten resin supply device for supplying a molten resin, a spinning unit for spinning the molten resin, and a connecting member for connecting the molten resin supply device and the spinning unit. The connecting member includes a first member made of a heat-resistant material having a first surface facing the molten resin supply device and a second surface opposite to the first surface, and a first member facing the spinning unit. And a second member made of a heat resistant material having a second surface opposite to the first surface, the first member having a convex portion on the second surface, and a top of the convex portion , And the second member has a concave portion in the second surface, into which the convex portion can be inserted, and the second member has the first through hole passing therethrough and between the first surface and the second surface. A second through hole passing through the bottom of the recess and passing between the first surface and the second surface; The molten resin supply device and the first member are connected, the first through hole is in communication with the discharge flow path of the molten resin supply device, and the spinning unit and the second member are connected; The second through hole is in communication with the resin flow path of the spinning unit, and the second surface of the first member and the second surface of the second member face each other, and the convex portion is inserted into the concave portion The second member is supported by the top of the convex portion of the first member, and the second member is tilted with respect to the first member while maintaining the communication between the first through hole and the second through hole. It is intended to provide a melt spinning apparatus which is adapted to

  Further, the present invention is a melt spinning apparatus comprising: a molten resin supply apparatus for supplying a molten resin; a spinning unit for spinning the molten resin; and a connecting member for connecting the molten resin supply apparatus and the spinning unit. The connecting member includes a first member made of a heat resistant material having a first surface facing the molten resin supply device and a second surface opposite to the first surface, and a first member facing the spinning unit A second member made of a heat resistant material having a first surface and a second surface opposite to the first surface, the second member having a convex portion on the second surface, and The second member has a second through hole passing through the top and between the first surface and the second surface, and the first member has a concave portion in the second surface, into which the convex portion can be inserted. A first penetration through the bottom of the recess and through between the first surface and the second surface , The molten resin supply device and the first member are connected, the first through hole is in communication with the discharge flow path of the molten resin supply device, and the spinning unit and the second member are connected. The second through hole communicates with the resin flow path of the spinning unit, the second surface of the first member faces the second surface of the second member, and the convex portion is inserted into the concave portion. Then, the second member is supported by the bottom of the concave portion of the first member to maintain the communication between the first through hole and the second through hole while the second member is in contact with the first member. The present invention provides a melt spinning apparatus adapted to be tilted.

  According to the present invention, a fiber sheet having a uniform basis weight can be easily produced.

FIG. 1 is a cross-sectional view showing the structure of the melt spinning apparatus of the present invention. Fig.2 (a) is a perspective view of the 1st member used for the melt spinning apparatus shown in FIG. 1, FIG.2 (b) is one Embodiment of the 2nd member used for the melt spinning apparatus shown in FIG. FIG. 3 (a) is an enlarged view of an essential part of the structure of the first member used in the melt spinning apparatus shown in FIG. 1, and FIG. 3 (b) shows the melt spinning apparatus shown in FIG. It is a principal part enlarged view when the structure of the 2nd member used is cross-sectionally viewed. FIG. 4 is a schematic view from above showing a state in which a plurality of melt spinning devices shown in FIG. 1 are provided and spun. FIGS. 5 (a) and 5 (b) are perspective views of the first member and the second member used in the melt-spinning apparatus of another embodiment, respectively. FIG. 6 is a graph showing the basis weight distribution in the fiber sheets of Example 1 and Comparative Example 1.

  Hereinafter, the present invention will be described based on its preferred embodiments with reference to the drawings. FIG. 1 shows a cross-sectional view showing the structure of a first embodiment of the electrospinning apparatus of the present invention. A melt spinning apparatus 10 shown in FIG. 1 includes a molten resin supply device 20, a spinning unit 30, and a connecting member 40 connecting the both. Each member will be described below

  The melt spinning device 10 is provided with a molten resin supply device 20. The molten resin supply device 20 includes a kneading device and a gear pump (both are not shown) inside. The kneading apparatus melts and kneads a thermoplastic resin having fiber forming ability, and supplies it to the discharge flow channel 21. The kneading apparatus includes a metal cylinder and a metal screw (not shown) inserted into the cylinder. The cylinder is heatable by a heater (not shown). The screw is, for example, of a uniaxial or biaxial type. The kneading apparatus is provided with a hopper (not shown), and the thermoplastic resin as a raw material is supplied into the cylinder through the hopper. The thermoplastic resin supplied into the cylinder is melted by heat and is kneaded by a screw, and is delivered by a gear pump to a spinning unit 30 described later. From the viewpoint of quantitatively supplying the molten resin to the discharge flow channel 21, it is preferable that the molten resin supply device 20 internally include a kneading device and a gear pump in this order along the supply direction of the molten resin. .

  The melt spinning apparatus 10 comprises a spinning unit 30. The spinning unit 30 includes a spinning unit 30A and a circulating unit 30B. The spinning unit 30 discharges and spins the molten resin supplied from the molten resin supply device 20. The spinning unit 30A of the spinning unit 30 includes a hollow needle-like nozzle 31 in communication with the discharge flow path 21 of the molten resin supply device 20. The nozzle 31 can discharge the molten resin supplied from the molten resin supply device 20 from the discharge port 31 a of the nozzle 31 through a resin flow path 38 described later. When the melt spinning apparatus 10 is used in a melt electrospinning method, the nozzle 31 is preferably made of a conductor such as metal from the viewpoint of improving the chargeability.

  The lower limit of the inner diameter of the discharge port 31a of the nozzle 31 can be set to preferably 30 μm or more, and more preferably 100 μm or more. On the other hand, the upper limit thereof can be set preferably to 3000 μm or less, more preferably 2000 μm or less. The inner diameter of the discharge port 31a can be set to preferably 30 μm to 3000 μm, and more preferably 100 μm to 2000 μm. By setting the inner diameter of the discharge port 31a within this range, the molten resin can be fed easily and quantitatively. When the melt spinning apparatus 10 is used for melt electrospinning, the lower limit of the outer diameter of the discharge port 31a can be set to preferably 0.1 mm or more, more preferably 0.2 mm or more. The upper limit of the outer diameter of the discharge port 31a can be set preferably to 10 mm or less, more preferably 7 mm or less. By setting the inner diameter and the outer diameter of the discharge port 31 a in this range, the molten resin can be efficiently charged.

  When the melt spinning apparatus 10 is used in a melt electrospinning method, as shown in FIG. 1, the spinning unit 30A may include an electrode 32 for charging the nozzle 31 to generate an electric field. The electrode 32 is preferably made of a conductive material, and the outer surface thereof is supported by a support member 33 made of an electrically insulating material. The electrode 32 is a concave surface electrode which is disposed so as to surround the nozzle 31 and whose inner surface is a substantially wedge-shaped concave surface 32a. The open end of the concave surface 32a may be a perfect circle or an ellipse. In particular, when the melt spinning apparatus 10 is used in a melt electrospinning method, the open end of the concave surface 32a should be a perfect circle in order to concentrate the charge on the nozzle 31 and increase the charge amount of the molten resin to be discharged. preferable. Although FIG. 1 shows a state in which a negative voltage is applied to the electrode 32 by the high voltage generator 34, a positive voltage may be applied to the electrode 32 instead.

  It is preferable that the concave surface 32a has a value such that the normal at any position thereof passes through the tip of the nozzle 31 or in the vicinity thereof. From this viewpoint, it is particularly preferable that the concave surface 32a has the same shape as the inner surface of a true spherical shell.

  As shown in FIG. 1, the spinning unit 30A may further include a covering 35. The cover 35 preferably covers the entire surface of the concave surface 32 a of the electrode 32. The electrode 32 and the cover 35 are in direct contact with each other. The surface of the cover 35 covering the concave surface 32 a of the electrode 32 has a shape complementary to the concave surface 32 a of the electrode 32. Further, the surface of the cover 35 exposed outward is a concave surface 35 a. The curvature of the concave surface may be the same as or different from the curvature of the concave surface 32 a of the electrode 32.

  When the melt spinning apparatus 10 is used in a melt electrospinning method, the coating 35 is preferably made of a dielectric from the viewpoint of improving the chargeability of the nozzle 31. By arranging the covering 35 made of a dielectric in contact with the concave surface 32 a of the electrode 32, the charge amount of the nozzle 31 can be further increased. The cover 35 may be composed of a single type of dielectric, or may be a laminate in which a plurality of types of dielectrics are stacked.

  As a dielectric used for the covering 35, ceramic materials such as mica, alumina, zirconia, barium titanate which are insulating materials, Bakelite (phenol resin), nylon (polyamide), vinyl chloride resin, polystyrene, polyester, polypropylene And resin-based materials such as polytetrafluoroethylene and polyphenylene sulfide. The dielectric used for the cover 35 can contain an antistatic agent. By containing the antistatic agent, when charged molten resin, fibers and the like adhere to the covering 35, the charging of the covering 35 can be reduced.

  The flow-through unit 30B which constitutes a part of the spinning unit 30 together with the spinning unit 30A is disposed between the molten resin supply device 20 and the spinning unit 30A, as shown in FIG. The flow part 30 </ b> B has a double-pipe structure formed of an inner cylinder 36 and an outer cylinder 37 covering the inner cylinder 36. A resin flow passage 38 is formed in the inner cylinder 36. One end of the resin flow path 38 is in communication with the discharge flow path 21 of the molten resin supply device 20, and the other end is in communication with the nozzle 31, and the molten resin discharged from the molten resin supply device 20 is spun. It is distributed to the department 30A. A space between the inner cylinder 36 and the outer cylinder 37 is a gas flow passage 39 through which gas can flow. As described above, in the flow part 30B, the resin flow path 38 for flowing the molten resin is formed, and the gas flow passage 39 is formed so as to surround the resin flow path 38.

  The gas flow passage 39 is opened so as to surround the nozzle 31 in the spinning unit 30A. As shown in FIG. 1, a plurality of gas flow passages 39 may be formed. From the viewpoint of convenience and improvement of the formability of the microfibers, it is preferable to use air, which is a heating fluid, as the gas to be circulated to the gas flow passage 39. Air is supplied from a gas inlet 45 provided in a second member 42 described later.

  The melt spinning apparatus 10 includes a connecting member 40 that connects the molten resin supply device 20 and the spinning unit 30. As shown in FIG. 1, the connecting member 40 includes a first member 41 having a convex portion protruding toward the spinning unit 30, a second member 42 having a concave portion into which the convex portion can be inserted, and a first member 41. A fixing member 43 for fixing the member 41 and the second member 42 is provided. The first member 41 is connected to the molten resin supply device 20 by fixing means (not shown) such as screws and bolts. Similarly, the second member 42 is connected to the spinning unit 30 by fixing means (not shown) such as screws and bolts.

  The connecting member 40 will be described in detail. The first member 41 is, as shown in FIG. 2A, a first surface 41S facing the molten resin supply device 20 and a second surface opposite to the first surface 41S. And a surface 41R. The first surface 41S and the second surface 41R are parallel to each other. The second surface 41R has a convex portion 41P formed in a substantially hemispherical shape so as to protrude from the second surface 41R at a substantially central portion thereof. A first through hole 41H is open at the top of the convex portion 41P. The first through hole 41H passes through the top of the convex portion 41P and penetrates between the first surface 41S and the second surface 41R. When the first member 41 is assembled to the molten resin supply device 20, the discharge flow passage 21 of the molten resin supply device 20 and the first through hole 41H communicate with each other.

  The first member 41 is provided with a fixing hole 41 a. The fixing member 43 is inserted into the fixing hole 41a. The fixing hole 41 a is used to fix the first member 41 and the second member 42 by the fixing member 43. In the embodiment shown in FIG. 2A, fixing holes 41a are provided at central portions of four sides of the rectangular first member 41 in plan view.

  As shown in FIG. 2B, the second member 42 has a first surface 42S facing the spinning unit 30, and a second surface 42R opposite to the first surface 42S. The first surface 42S and the second surface 42R are parallel to each other. The second surface 42R has a concave portion 42P which is sunk in a substantially hemispherical shape in a substantially central portion thereof. In the state where the second member 42 and the above-described first member 41 are fixed, the convex portion 41P of the first member 41 can be inserted into the concave portion 42P. The concave portion 42P has a second through hole 42H at its bottom. The second through holes 42H pass through the bottom of the concave portion 42P and pass between the first surface 42S and the second surface 42R. In a state where the second member 42 is assembled to the spinning unit 30, the resin flow path 38 and the nozzle 31 in the spinning unit 30 communicate with the second through hole 42H.

  Further, the second member 42 is provided with a fixing hole 42 a for fixing the second member 42 and the first member 41 described above by the fixing member 43. The fixing hole 42a penetrates between the first surface 42S and the second surface 42R. In the embodiment shown in FIG. 2 (b), fixing holes 42a are provided at the central portions of the four sides of the rectangular second member 42 in plan view.

  In the fixing member 43, both members 41 are in a state where the second surface 41R of the first member 41 and the second surface 42R of the second member 42 face each other, and the convex portion 41P is inserted into the concave portion 42P. , 42 are members for fixing. In the embodiment shown in FIGS. 2 (a) and 2 (b), the fixing member 43 can be a known fastening member such as a screw or a bolt.

  As shown in FIG. 1, in a state where the first member 41 and the second member 42 are assembled, the second surface 41R of the first member 41 and the second surface 42R of the second member 42 face each other, and The convex portion 41P of the first member 41 is inserted into the concave portion 42P of the second member 42. When the convex portion 41P is inserted into the concave portion 42P, the entire convex portion 41P is not inserted into the concave portion 42P, and only the upper portion including the top of the convex portion 41P is inserted into the concave portion 42P. Be done. The convex portion 41P and the concave portion 42P are shaped and sized to be in such an inserted state. By inserting the convex portion 41P into the concave portion 42P in such a state, the second member 42 is supported by the top of the convex portion 41P of the first member 41. Thereby, the second member 42 is tilted with respect to the first member 41 while maintaining the communication between the first through hole 41H of the first member 41 and the second through hole 42H of the second member 42. . That is, the second surface 41R of the first member 41 is nonparallel to the second surface 42R of the second member 42. The tilt direction is in the xz plane and in the yz plane in the xyz rectangular coordinate system shown in FIG. The xy plane in FIG. 2A is parallel to the second surface 41R of the first member 41.

  In the state where the convex portion 41P is inserted into the concave portion 42P, the first through hole 41H opened at the top of the convex portion 41P and the second through hole 42H opened at the bottom of the concave portion 42P communicate with each other. This communication state is maintained even if the second member 42 tilts relative to the first member 41. Since the convex portion 41P is substantially hemispherical, the spinning direction and angle of the spinning unit 30 connected to the second member 42 can be three-dimensionally freely changed along with the tilting of the second member 42. Can. The direction and angle of tilting of the spinning unit 30 can be suitably changed by adjusting the degree of loosening or tightening by the fixing member 43.

  From the viewpoint of achieving both the flow of molten resin in the connecting member 40 and the three-dimensional tilting of the spinning unit 30, as shown in FIG. 3A, the diameter D1 of the convex portion 41P is 20 mm or more and 100 mm or less Is preferred. The diameter d1 of the first through hole 41H is preferably 5 mm or more and 20 mm or less. The height H1 of the convex portion 41P is preferably 5 mm or more and 20 mm or less.

  From the same viewpoint, as shown in FIG. 3B, the diameter D2 of the concave portion 42P is preferably 20 mm or more and 100 mm or less. The diameter d2 of the second through hole 42H is preferably 5 mm or more and 20 mm or less. The depth H2 of the concave portion 42P is preferably 5 mm or more and 20 mm or less.

  From the viewpoint of quantitatively adjusting the direction and angle of tilting of the spinning unit 30, the apparatus 10 measures the angle between the second surface 41R of the first member 41 and the second surface 42R of the second member 42. Preferably, it further comprises measuring means. The angle measuring means may be, for example, a protractor, a protractor, a laser type angle meter, a micrometer head and the like. When using a micrometer head among these angle measuring means, from the viewpoint of performing quantitative and three-dimensional angle measurement, at least one of the xz plane direction and the yz plane direction shown in FIG. Preferably, they are provided one by one. The angle measurement means may be provided by replacing at least one of the fixing members 43, and may be provided separately from the fixing member 43. From the viewpoint of improving the fixability of the first member 41 and the second member 42, it is preferable that the angle measurement means be provided separately from the fixing member 43.

  From the viewpoint of successfully supplying the molten resin from the molten resin supply device 20, at least one of the first member 41 and the second member 42 has heating means for heating or keeping the molten resin warm. Is preferred. As a heating means, a known means such as a heater can be used. As a temperature for heating or keeping warm, it is preferable to heat or keep warm at a temperature equal to or higher than the melting point of the raw material resin used for producing fibers. From the same point of view, it is preferable that the first member 41 and / or the second member 42 be made of a heat-resistant material and generally made of a material having high heat conductivity, and examples of the material include alumina and carbonized material. Ceramics such as silicon and metals such as stainless steel and copper may be mentioned. Among these, metals such as stainless steel are more preferable from the viewpoint of achieving both processability and strength.

  As shown in FIG. 1, the second member 42 is provided with a gas inlet 45. Gas is supplied to the gas flow passage 39 from a gas supply source (not shown) installed outside the melt spinning apparatus 10 through the gas inlet 45. The gas supplied to the gas flow passage 39 is not particularly limited, but it is preferable to use a heated gas from the viewpoint of heat retention or heating of the molten resin. From the viewpoint of convenience, it is preferable to use heated air as the gas.

  As shown in FIG. 1, the melt spinning device 10 may further be provided with a connection portion 50 for connecting the connection member 40 and the spinning unit 30. The connection portion 50 is a first connection member 51 connected to the first surface 42S side of the second member 42, and a second connection member 52 that presses one end of the flow portion 30B against the first connection member 51 and fixes the first connection member 51. Equipped with The first connection member 51 and the second connection member 52 are coupled by coupling means such as screwing or bolt fastening, for example.

  The first connection member 51 has a through hole 51a, and in the state where the connecting member 40 and the connecting portion 50 are connected, the through hole 51a, the second through hole 42H in the connecting member 40, and the circulating portion 30B. It communicates with the resin flow path 38 in the By having this structure, the molten resin supplied from the molten resin supply device 20 can be supplied to the nozzle 31. The first connection member 51 has a gas flow hole 51 b and a gas distribution passage (not shown) in addition to the through hole 51 a. The gas flow hole 51 b is formed such that the gas flow hole 51 b and the gas flow passage 39 in the spinning unit 30 communicate with each other in a state where the connection portion 50 and the spinning unit 30 are assembled. With this structure, the gas supplied from the gas inlet 45 can be supplied to the nozzle 31 side. The first connection member 51 and the second connection member 52 of the connection portion 50 are preferably made of, for example, a metal in terms of heat resistance, mechanical strength, and the like. When the melt spinning apparatus 10 is used in a melt electrospinning method, at least the first connection member 51 is preferably grounded from the viewpoint of preventing application of a voltage to the molten resin supply device 20.

  As shown in FIG. 1, in the melt-spinning apparatus 10, the collection portion 61 of the fiber F is disposed at a position facing the discharge port 31 a of the nozzle 31. The collection unit 61 is used to collect the molten resin spun from the nozzle 31 as the fiber F. In the embodiment shown in FIG. 1, the collecting portion 61 is a flat plate, but the shape is not particularly limited as long as it can collect molten resin, and it is a shape such as a belt conveyor or a peripheral surface of a cylinder. May be

  When the collection unit 61 is disposed in the melt spinning apparatus 10, the lower limit value of the distance between the collection unit 61 and the tip of the nozzle 31 can be preferably 50 mm or more, and more preferably 100 mm or more. The upper limit value is preferably 3000 mm or less, more preferably 2000 mm or less. The distance between the collection portion 61 and the tip of the nozzle 31 can be preferably 50 mm or more and 3000 mm or less, and more preferably 100 mm or more and 2000 mm or less.

  In the melt spinning apparatus 10 having the above configuration, a communication passage connecting the molten resin supply device 20 and the nozzle 31 is formed between the molten resin supply device 20 and the nozzle 31. Specifically, the flow passage of the molten resin communicated from the molten resin supply device 20 to the nozzle 31 includes the first through holes 41H and the second through holes 42H of the connecting member 40, the through holes 51a of the connecting member 50, and the circulating portion. The resin flow path 38 of 30 B is formed via the communication path in communication. In addition, a flow passage of gas communicated from the gas introduction port 45 provided in the second member 42 of the connection member 40 to the gas flow passage 39 provided in the flow passage portion 30B is formed. In the present embodiment, a gas flow passage (gas flow passage 39) is provided to surround the communication passage. Note that "enclose the communication passage" means including the form of surrounding the part of the length in addition to the case of surrounding the entire length of the communication passage. And according to this melt spinning apparatus 10, the second member 42 in the connecting member 40 is in the xz plane and the yz plane with respect to the first member 41 while maintaining the communication state of the flow path of the molten resin. Since the inside can be tilted, the discharge direction of the fiber F can be arbitrarily adjusted. As a result, the basis weight of the fiber sheet obtained by depositing the fibers F can be made more uniform.

  In the production of a fiber sheet using the melt spinning apparatus 10, a usual melt spinning method, melt electrospinning method or the like can be employed. Examples of the method of spinning by the melt spinning method include a meltblown method. In the melt-spinning apparatus 10 of the present invention, it is possible to inject gas through the gas flow passage 39 along the extending direction of the nozzle 31. Therefore, it is possible to produce microfibers particularly by the meltblown method, and the fibers Can be used to form a fibrous sheet.

  For example, in the meltblown method, a resin composition containing a raw material resin is supplied to a molten resin supply device 20, and the resin composition is melt-kneaded by a kneading device provided in the molten resin supply device 20. The resin composition is kneaded by the rotation of a screw and sent out to the nozzle 31 by a gear pump or the like provided in the molten resin supply device 20 and discharged from the discharge port 31 a of the nozzle 31. By blowing a gas toward the discharged molten resin R through the gas flow passage 39, the molten resin R is transported to the side of the collection portion 61 while generating a small diameter fiber. The fiber deposited in the collection unit 61 is conveyed to a downstream process by, for example, a conveying means such as a belt conveyor, and then press-processed by a nip roll, a press roll or the like to produce the fiber sheet of the present invention. The spinning conditions in the melt spinning method are not particularly limited, and appropriate conditions are adopted according to the type of resin, the use of the product, and the like.

  On the other hand, when spinning is performed by melt electrospinning, microfibers can be relatively easily formed. The molten electrospinning method is a method of charging the molten resin R discharged by discharging the molten resin R in a state in which an electric field is generated in the vicinity of the nozzle 31, and stretching and elongating to form fibers. .

  Also in the melt electrospinning method, for example, as in the case of the melt spinning method described above, the resin composition containing the raw material resin is supplied to the molten resin supply device 20, and the resin composition is provided in the molten resin supply device 20. Heat and melt in a kneading apparatus. The molten resin composition is kneaded by the rotation of a screw, and is discharged toward the nozzle 31 by a gear pump provided in the molten resin supply device 20 and discharged from the discharge port 31 a of the nozzle 31.

  The discharged molten resin R is spun by electrospinning. Specifically, the electrode 32 is connected to the high voltage generator 34 to apply a voltage to generate an electric field between the tip of the nozzle 31 and the electrode 32, and the molten resin R discharged from the discharge port 31 a of the nozzle 31 To charge. The charged molten resin R is spun so as to repeat drawing to form ultrafine fibers by its electric repulsion. The fibers generated from the molten resin R are transported by the gas from the gas flow passage 39 and deposited on the surface of the collection portion 61.

  As in the case of the melt spinning method described above, the fibers deposited in the collection portion 61 are transported to the downstream process by, for example, a transport means such as a belt conveyor, and then press-processed by a nip roll or press roll. The fiber sheet of the invention can be produced.

  It is preferable that a plurality of melt spinning devices 10 be provided from the viewpoint of enhancing the production amount of the fibers spun by the melt spinning device 10 and improving the productivity. In this case, it is preferable that a plurality of melt spinning devices 10 be provided in parallel with the direction orthogonal to the fiber conveyance direction, from the viewpoint of making the basis weight of the fibers uniform in the width direction. The number of melt spinning apparatuses 10 is not particularly limited, and may be provided in a line in a direction perpendicular to the fiber conveyance direction, or may be provided in a plurality of lines.

  For example, as shown in FIG. 4, two melt spinning devices 10 can be provided along a direction orthogonal to the fiber transport direction. In the figure, the fiber transport direction is the direction orthogonal to the paper surface. When spinning is performed by the method shown in FIG. 4 to produce the fiber sheet S, distribution may occur in the basis weight of the fibers in the width direction of the fiber sheet S, that is, in the direction orthogonal to the transport direction. Then, from the viewpoint of making the basis weight of the fibers in the width direction of the fiber sheet S even more uniform, when a plurality of melt spinning devices 10 are installed along the direction orthogonal to the transport direction of the fiber sheet S, FIG. It is preferable to adjust the degree of tilting so that the basis weight of the fibers in the width direction of the fiber sheet S becomes uniform by tilting each melt spinning apparatus 10 as shown in FIG. In FIG. 4, two melt spinning devices 10 are installed, and the melt spinning in the sheet of FIG. 4 is performed so that the nozzle 31 in each melt spinning device 10 faces the center in the width direction of the fiber sheet S. Although the device 10 is shown in a tilted state, the tilting direction is not limited thereto. For example, each melt spinning device 10 may be tilted in a plane orthogonal to the paper surface of FIG. 4.

  According to the present embodiment, it is possible to produce a fiber sheet having fibers of various fiber diameters depending on the conditions for carrying out the melt spinning method. In particular, microfibers called nanofibers can be easily produced. The fiber diameter of the nanofibers is preferably 100 nm or more and 3000 nm or less when the fiber diameter is represented by a circle equivalent diameter. The fiber diameter can be measured, for example, by scanning electron microscope (SEM) observation.

  Next, a second embodiment of the present invention will be described with reference to FIG. The description of the first embodiment is appropriately applied to points that are not particularly described in the present embodiment. In FIG. 5, the same members as those in FIGS. 1 to 4 are denoted by the same reference numerals.

  In the second embodiment shown in FIG. 5, the shapes of the first member 41 and the second member 42 in the connecting member 40 are different from those in the first embodiment. The other structure in the melt spinning apparatus 10 is the same as that of the first embodiment. In the present embodiment, as shown in FIG. 5A, the first member 41 ′ of the connecting member 40 is opposite to the first surface 41S ′ facing the molten resin supply device 20 and the first surface 41S ′. And a second surface 41R 'located. The first surface 41S 'and the second surface 41R' are planes parallel to each other. The second surface 41R 'has a convex portion 41P' formed in a substantially semi-cylindrical shape so as to protrude from the second surface 41R 'at a substantially central portion thereof. A first through hole 41H 'is opened at the central portion in the height direction and the circumferential direction of the convex portion 41P'. The first through holes 41H 'pass through the central portion of the convex portion 41P' and penetrate between the first surface 41S 'and the second surface 41R'. When the first member 41 'is assembled to the molten resin supply device 20, the discharge flow passage 21 of the molten resin supply device 20 and the first through hole 41H' are in communication with each other.

  The first member 41 'is provided with a fixing hole 41a'. The fixing member 43 is inserted into the fixing hole 41a '. The fixing hole 41 a ′ is used to fix the first member 41 ′ and the second member 42 ′ by the fixing member 43. In the embodiment shown in FIG. 5A, fixing holes 41a 'are provided at central portions of four sides of the rectangular first member 41' in plan view.

  As shown in FIG. 5 (b), the second member 42 ′ has a first surface 42 S ′ facing the spinning unit 30 and a second surface 42 R ′ located on the opposite side of the first surface 42 S ′. There is. The first surface 42S 'and the second surface 42R' are parallel to each other. The second surface 42R 'has a concave portion 42P' which is sunk in a substantially semi-cylindrical shape at a substantially central portion thereof. When the second member 42 'and the above-described first member 41' are fixed, the convex portion 41P 'of the first member 41' can be inserted into the concave portion 42P '. The concave portion 42P 'has a second through hole 42H' at the center in the height direction and the circumferential direction at the bottom thereof. The second through holes 42H 'pass through the central portion of the bottom of the concave portion 42P' and pass between the first surface 42S 'and the second surface 42R'. In a state where the second member 42 'is assembled to the spinning unit 30, the resin flow path 38 and the nozzle 31 in the spinning unit 30 communicate with the second through hole 42H'.

  Further, the second member 42 'is provided with a fixing hole 42a' for fixing the second member 42 'and the first member 41' described above by the fixing member 43. The fixing holes 42a 'pass through between the first surface 42S' and the second surface 42R '. In the embodiment shown in FIG. 5 (b), fixing holes 42a 'are provided at the central portions of the four sides of the rectangular second member 42' in plan view.

  In a state where the first member 41 'and the second member 42' are assembled, the second surface 41R 'of the first member 41' and the second surface 42R 'of the second member 42' face each other, and The convex portion 41P 'of the first member 41' and the concave portion 42P 'of the second member 42' are aligned in the height direction, and the convex portion 41P 'is inserted into the concave portion 42P'. Be done. In the state where the convex portion 41P 'is inserted into the concave portion 42P', the entire convex portion 41P 'is not inserted into the concave portion 42P', and only the upper portion including the top ridge line of the convex portion 41P ' It is inserted in concave 42P '. The convex portion 41P 'and the concave portion 42P' are shaped and sized to be in such an inserted state. By inserting the convex portion 41P 'into the concave portion 42P' in such a state, the second member 42 'is supported by the top ridge of the convex portion 41P' of the first member 41 '. become. Thereby, the second member 42 'is opposed to the first member 41' while maintaining the communication between the first through hole 41H 'of the first member 41' and the second through hole 42H 'of the second member 42'. Will be inclined. That is, the second surface 41R 'of the first member 41' is nonparallel to the second surface 42R 'of the second member 42'. The direction of tilting is only in the xz plane in the xyz coordinate system shown in FIG. 5 (a). Due to this tilting, the spinning direction and angle of the spinning unit 30 connected to the second member 42 'can be freely changed in two dimensions. The direction and angle of tilting of the spinning unit 30 can be suitably changed by adjusting the degree of loosening or tightening by the fixing member 43.

  Next, matters common to the above-described embodiments will be described. The molten resin used for manufacture of a fiber sheet contains a thermoplastic resin. Examples of thermoplastic resins include polyolefin resins such as polyethylene and polypropylene; polyester resins such as polyethylene terephthalate; polyamide resins such as nylon 6; vinyl polymers such as polyvinyl chloride; acrylic polymers such as polyacrylic acid . These resins can be used alone or in combination of two or more.

  The molten resin may be blended with an additive in addition to the thermoplastic resin as long as the effects of the present invention are not impaired. Examples of the additive include a charging agent, an antioxidant, a neutralizing agent, a light stabilizer, an ultraviolet light absorber, a lubricant and the like. Examples of the charge agent include salts of higher fatty acids such as stearic acid and metals such as Na, K and Zn, and surfactants such as alkyl sulfonates and quaternary ammonium salts.

  Although the present invention has been described above based on its preferred embodiments, the present invention is not limited to the embodiments. For example, in the first embodiment, the convex portion 41P is provided on the first member 41, and the concave portion 42P is provided on the second member 42. Instead of this, the first member 41 and the second member 42 are provided. Under the condition that the communication state of the through holes 41H and 42H is maintained, the first member 41 may be provided with a concave portion and the second member 42 may be provided with a convex portion. The same applies to the second embodiment, and in the embodiment, the convex portion 41P 'is provided to the first member 41' and the concave portion 42P 'is provided to the second member 42'. Instead, a concave portion is provided in the first member 41 'on condition that the communication state of the through holes 41H' and 42H 'of the first member 41' and the second member 42 'is maintained, and the second member 42' is provided. May have a convex portion.

  Further, in the embodiment shown in FIG. 4, the two melt spinning devices 10 and 10 are disposed along the direction orthogonal to the transport direction of the fiber sheet S, but instead, three or more melt spinning devices are provided. You may arrange ten. Alternatively, a plurality of melt spinning devices 10 may be disposed along a direction orthogonal to the transport direction of the fiber sheet S, and a plurality of melt spinning devices 10 may be disposed along the transport direction.

  Hereinafter, the present invention will be described in more detail by way of examples. However, the scope of the present invention is not limited to such embodiments.

Example 1
From a resin composition containing 80% by mass of polypropylene (PP; manufactured by PolyMirae, MF 650Y) as a thermoplastic resin and 20% by mass of zinc stearate as an additive using the melt spinning apparatus 10 shown in FIGS. 1 to 4 The resulting molten resin R was spun by electrospinning to obtain fibers. The spinning conditions of the electrospinning method were as follows, and collected on a belt conveyor provided on the collection portion 61 so as to have a basis weight of 33 g / m ² to obtain a fiber sheet of 300 mm in the width direction.

・ Manufacturing environment: 27 ° C, 50% RH
· Heating temperature in the molten resin supply device 20: 250 ° C
・ Discharge amount of molten resin: 912 g / hr
-Applied voltage of nozzle 31 (made of stainless steel): 0 kV (grounded)
· Applied voltage to electrode 32: -38 kV
The voltage applied to the collection unit 61: 0 kV (grounded)
The distance between the nozzle tip and the collection unit 61: 1000 mm
・ Temperature of gas ejected from gas flow passage 39: 260 ° C.
· Flow rate of gas ejected from the gas flow passage 39: 200 L / min
・ The number of melt spinning devices 10: 4 (2 each in upper and lower two rows)
The tilt angle of the spinning unit 30: 3 ° in the horizontal direction (x-z direction) inward, 0 ° in the vertical direction (y-z direction)

Comparative Example 1
The inclination angle of the spinning unit 30 is 0 ° (a state where the nozzle 31 and the collection unit 61 are orthogonal to each other), and a fiber is provided on the collection unit 61 so as to have a basis weight of 64 g / m ² Was spun under the same conditions as in Example 1 to produce a fiber sheet.

[Evaluation]
With respect to the fiber sheets produced in Example 1 and Comparative Example 1, a portion in the width direction 300 mm × longitudinal direction 100 mm of the central portion of the fiber sheet was taken out and further divided into 10 in the width direction to be 30 mm wide × 100 mm longitudinal A sample for evaluation was prepared. The basis weight of each evaluation sample was measured to calculate the average basis weight. The relative basis weight (standardized basis weight) of each sample for evaluation when the average basis weight in the sample for evaluation in the width direction position 0 to 300 mm is 1 with the one end of the fiber sheet as the position 0 mm in width direction is shown in FIG. Indicated. Moreover, the dispersion | variation in the standardization basis weight in each width direction position was calculated as a standard deviation.

  As shown in FIG. 6, the relative basis weight of the fiber sheet of Example 1 is the ratio of the highest standardized basis weight (width direction position 0 to 30 mm) to the lowest standardized basis weight (width direction position 150 to 180 mm) Is about 1.3 times, and the standard deviation is 0.07. On the other hand, the relative basis weight of the fiber sheet of Comparative Example 1 has a ratio of the highest standardized basis weight (crosswise position 240 to 270 mm) to the lowest standardized basis weight (crosswise position 120 to 150 mm) about 2 And the standard deviation was 0.24. Therefore, according to Example 1, it can be seen that it is possible to manufacture a fiber sheet having a small variation in basis weight in the width direction and a uniform basis weight.

DESCRIPTION OF SYMBOLS 10 Melt spinning apparatus 20 Melt resin supply apparatus 30 Spinning unit 31 Nozzle 39 Gas flow path 40 Connection member 41 1st member 42 2nd member 43 Fixing member 45 Gas introduction port 50 Connection part 61 Collection part

Claims (6)

A molten resin supply device for supplying a molten resin;
A spinning unit for spinning the molten resin;
A melt spinning apparatus comprising: a connecting member for connecting the molten resin supply apparatus and the spinning unit;
The connecting member is a first member made of a heat resistant material having a first surface facing the molten resin supply device and a second surface opposite to the first surface, and a first surface facing the spinning unit And a second member made of a heat-resistant material having a second surface opposite to the first surface,
The first member has a convex portion on its second surface, and has a first through hole passing through the top of the convex portion and passing between the first surface and the second surface,
The second member has, on its second surface, a concave portion into which the convex portion can be inserted, and a second through hole passing through the bottom of the concave portion and passing between the first surface and the second surface Have
The molten resin supply device and the first member are connected, and the first through hole is in communication with the discharge flow path of the molten resin supply device,
The spinning unit and the second member are connected, and the second through hole is in communication with the resin flow path of the spinning unit,
When the second surface of the first member and the second surface of the second member face each other and the convex portion is inserted into the concave portion, the second member is supported by the top of the convex portion of the first member. The melt spinning apparatus according to claim 1, wherein the second member is inclined relative to the first member while maintaining the communication between the first through hole and the second through hole. A molten resin supply device for supplying a molten resin;
A spinning unit for spinning the molten resin;
A melt spinning apparatus comprising: a connecting member for connecting the molten resin supply apparatus and the spinning unit;
The connecting member is a first member made of a heat resistant material having a first surface facing the molten resin supply device and a second surface opposite to the first surface, and a first surface facing the spinning unit And a second member made of a heat-resistant material having a second surface opposite to the first surface,
The second member has a convex portion on its second surface, and has a second through hole passing through the top of the convex portion and passing between the first surface and the second surface,
The first member has on the second surface thereof a concave portion into which the convex portion can be inserted, and a first through hole passing through the bottom of the concave portion and passing between the first surface and the second surface Have
The molten resin supply device and the first member are connected, and the first through hole is in communication with the discharge flow path of the molten resin supply device,
The spinning unit and the second member are connected, and the second through hole is in communication with the resin flow path of the spinning unit,
The second member is supported by the bottom of the concave portion of the first member when the second surface of the first member and the second surface of the second member face each other and the convex portion is inserted into the concave portion. The melt spinning apparatus according to claim 1, wherein the second member is inclined relative to the first member while maintaining the communication between the first through hole and the second through hole.   The melt spinning apparatus according to claim 1, wherein the connection member further comprises angle measurement means for measuring an angle between the first member and the second member.   The melt spinning apparatus according to any one of claims 1 to 3, further comprising heating means for heating the molten resin to at least one of the first member and the second member. The spinning unit is
A nozzle for discharging the molten resin supplied from the molten resin supply device;
An electrode for generating an electric field between the nozzle and the nozzle;
The electrode is a concave surface electrode in which a concave surface is disposed so as to surround the nozzle,
A communication passage is formed between the molten resin supply device and the nozzle, for connecting the molten resin supply device and the nozzle,
The melt spinning apparatus according to any one of claims 1 to 4, wherein a gas flow passage through which gas can flow is formed so as to surround the communication passage.   The manufacturing method of a fiber sheet using the melt spinning apparatus as described in any one of Claims 1-5.