CN107614764B - Nanofiber manufacturing device and nanofiber manufacturing method - Google Patents

Abstract

Provided are a nanofiber manufacturing apparatus and a nanofiber manufacturing method using a melt blowing method with improved productivity. The granular raw material (resin) charged into the hopper 2 is supplied into the heating cylinder 3 heated by the heater 4, melted, and then delivered to the front of the heating cylinder 3 by the screw 5 rotated by the motor 6. The heating cylinder 3 is provided with a head 7, and high-pressure gas is ejected from a gas ejection port 71 formed in the center of the head 7. The molten resin reaching the tip of the heating cylinder 3 passes through the inside of the head 7 and is discharged from the resin discharge port 73 of 6 extremely thin tubes disposed at a position retreating in the downstream direction of the resin discharge port 73. Thereby, the molten resin discharged from the resin discharge port 73 is extended to form fibers having a diameter of nanometer order.

Description

Nanofiber manufacturing device and nanofiber manufacturing method

Technical Field

The present invention relates to a nanofiber manufacturing apparatus and a nanofiber manufacturing method capable of providing high-quality nanofibers with a simple configuration.

Background

In recent years, demand has been rapidly increasing with the expansion of the use of nano-sized fibers, so-called nanofibers. With the expansion of the application of the nanofiber, the quality of the nanofiber is improved, and people need special nanofiber products which are suitable for the application. In addition, various known methods such as electrospinning and melt blowing are widely known for producing nanofibers, and these methods have advantages and disadvantages.

As the background art,patent document 1 discloses a method for producing a nonwoven fabric composed of a plurality of kinds of fibers by mixing solution-discharged fibers (solution-discharged fibers) into meltblown fibers. Specifically, the spinning solution discharged from the liquid discharge portion is ejected by the gas discharged from the gas discharge portion by the solution spinning unit, and is further fiberized into solution-discharged fibers, and the solution-discharged fibers are mixed into the fiber flow of the meltblown fibers discharged from the nozzle by the meltblowing method.

Non-patentdocument 1 discloses a method for producing nanofibers by an electric field spinning method.Non-patent document 1 discloses the following structure: in the case of producing nanofibers by the electrospinning method, it has been conventionally necessary to swell the resin with a solvent, but innon-patent document 1, the resin is swollen with heat without using a solvent, and thus ignition and explosion can be prevented when a solvent is used. In addition, the disadvantages of the nanofiber manufacturing method using the melt blowing method are also described in detail.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2010-185153

Non-patent document

Non-patent document 1: WEB-Journal No.151 nonwoven increasing publication (http:// www.webj.co.jp/index. html)

Disclosure of Invention

Problems to be solved by the invention

As described innon-patent document 1, in a method for producing nanofibers by a conventional melt blowing method, a method of blowing high-temperature air at a high speed and a method of suppressing the reduction of polymer discharge are considered in order to reduce the fiber diameter. When high-temperature air is ejected at high speed, the fiber diameter becomes small, but the length of the fiber is short and the fiber is in the form of a thin strip. On the other hand, in the case of suppressing the decrease in the discharge of the polymer, the production amount per unit time is significantly decreased. In either case, it is difficult to mass-produce nanofibers having excellent quality. In contrast, the electrospinning method can improve productivity. However, this method is complicated in apparatus, requires measures against fire and explosion, and is expensive in manufacturing cost.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a nanofiber manufacturing method and a nanofiber manufacturing apparatus, which can supply a large amount of nanofibers of good quality in a nanofiber manufacturing method of a meltblown system, and further eliminate factors that cause ignition or explosion, thereby improving safety.

Means for solving the problems

The nanofiber manufacturing apparatus of the present invention includes a liquid material discharge means for discharging a liquid material to a high-pressure gas flow discharged from a high-pressure gas discharge means, and is characterized in that a plurality of the liquid material discharge means are arranged around the high-pressure gas flow discharged from the high-pressure gas discharge means.

In addition, the nanofiber manufacturing apparatus of the present invention is characterized in that the liquid raw material discharge means includes an extrusion means for melting and extruding the raw material.

In addition, the nanofiber manufacturing apparatus of the present invention is characterized in that the liquid material discharge means includes means for supplying a dissolving material.

In the nanofiber manufacturing apparatus according to the present invention, the high-pressure gas ejection means is provided with a gas supply means for supplying a high-pressure and high-temperature gas, and the high-pressure gas ejection means ejects the high-temperature gas at a high pressure.

The nanofiber manufacturing apparatus according to the present invention further includes an angle adjusting means capable of adjusting an installation angle of the liquid material discharging means with respect to the high-pressure gas flow discharged from the high-pressure gas discharging means.

In the nanofiber manufacturing apparatus according to the present invention, at least 2 or more liquid material discharge units are disposed symmetrically with respect to the high-pressure gas discharge unit.

In the nanofiber manufacturing apparatus according to the present invention, the liquid material discharge means is disposed at equal intervals around the high-pressure gas stream discharged from the high-pressure gas discharge means.

In the nanofiber manufacturing apparatus according to the present invention, the high-pressure gas flow discharged from the high-pressure gas discharge unit is provided in a direction perpendicular to a surface on which the nanofiber manufacturing apparatus is installed.

In the nanofiber manufacturing method according to the present invention, the nanofiber is manufactured by discharging the liquid material from the liquid material discharging means to the high-pressure gas flow discharged from the high-pressure gas discharge means, and the liquid material discharging means is disposed in a plurality of numbers with the high-pressure gas flow discharged from the high-pressure gas discharge means as a center, and when the liquid material is discharged from the liquid material discharging means, a discharge angle of the liquid material discharged from the liquid material discharging means with respect to the high-pressure gas flow is adjusted.

Further, a nanofiber manufacturing method of the present invention is a nanofiber manufacturing method using a nanofiber manufacturing apparatus having a heating cylinder to which a raw material is supplied, a heating means for heating the heating cylinder, and an extrusion device for extruding the raw material in the heating cylinder, wherein a gas ejection port for ejecting high-pressure gas is provided at an end portion of the heating cylinder, a plurality of raw material discharge means for discharging the raw material in a molten state in the heating cylinder are provided around the gas ejection port, the raw material supplied is melted in the heating cylinder or the molten state of the raw material is maintained by heating the heating cylinder by the heating means, the raw material is discharged from the raw material discharge means by the extrusion device, and a gas flow is generated by the gas ejected from the gas ejection port, and forming nano-sized fibers by extending the discharged raw material by moving the discharged raw material from the outer periphery thereof with the flow of the ejected gas.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, nanofibers having a smaller diameter and higher quality can be safely produced. Further, in the production of nanofibers, the production amount per unit time, which is considered to be a disadvantage of the melt blowing method, can be compensated by providing a plurality of resin ejection units without using a device using a high voltage.

Drawings

Fig. 1 is a side view partially in cross section showing the overall structure of a first embodiment of a nanofiber manufacturing apparatus of the present invention.

Fig. 2 is a plan view of the head and the heating cylinder of the nanofiber manufacturing apparatus according to the first embodiment of the present invention.

Fig. 3 is a front view showing the appearance of the head tip of the nanofiber manufacturing apparatus according to the embodiment of the present invention.

3 fig. 3 4 3 is 3a 3 sectional 3view 3 of 3 the 3nanofiber 3 manufacturing 3apparatus 3 shown 3 in 3 fig. 3 3 3 taken 3 along 3 line 3a 3- 3a 3. 3

FIG. 5 is a sectional view of the nanofiber manufacturing apparatus shown in FIG. 4 taken along lines B-B, C-C, and D-D, respectively.

Fig. 6 is an explanatory view showing a resin flow path and a gas flow path inside the head of the nanofiber manufacturing apparatus according to the first embodiment of the present invention.

Fig. 7(a) is an explanatory view showing an example of a support structure of the resin ejection unit of the nanofiber manufacturing apparatus according to the first embodiment of the present invention, and fig. 7(b) is an explanatory view showing another example of a support structure of the resin ejection unit of the nanofiber manufacturing apparatus according to the first embodiment of the present invention.

Fig. 8 is a side view showing the overall structure of the second embodiment of the nanofiber manufacturing apparatus of the present invention.

Fig. 9 is a plan view showing the overall structure of the second embodiment of the nanofiber manufacturing apparatus of the present invention.

Fig. 10 is a front view showing a head structure of a second embodiment of the nanofiber manufacturing apparatus of the present invention.

Fig. 11 is an explanatory view for explaining the basic inventive concept of the nanofiber manufacturing apparatus and nanofiber manufacturing method according to the present invention.

Detailed Description

Hereinafter, specific embodiments of the present invention will be described. Needless to say, structures other than those described in the embodiment can be easily applied to the present invention within a range not departing from the gist of the present invention, and this is not necessary for explanation.

In the present invention, nanofibers are formed by supplying a liquid material to a fluid (preferably a gaseous fluid) discharged at a high pressure, but in the present specification, particularly when the fluid is referred to as "gas" without specifying a composition, the fluid includes a gas having all of the compositions or molecular structures. In the present specification, the term "raw material" means all materials used in forming nanofibers, and examples using a synthetic resin as the "raw material" are described in the following examples, but the present invention is not limited thereto, and various constituent materials may be used. In the present specification, the term "liquid raw material" is not limited to the raw material being liquid, and includes a "molten raw material" applied to the first embodiment in which a solid raw material is melted and extruded by an extrusion device to form nanofibers, and a "dissolved raw material" applied to the second embodiment in which a solid raw material or a liquid raw material is dissolved in a predetermined solvent in advance to have a predetermined concentration, and then the solution is sent out by an appropriate means and discharged or extruded from a discharge port to form nanofibers. That is, the "liquid raw material" in the present invention means a raw material that needs to have a viscosity to such an extent that the "raw material" can be supplied (ejected or discharged) from a supply port (ejection port or discharge port), and in the present invention, the "raw material" having such a liquid property is referred to as a "liquid raw material".

As will be described later in detail, a common basic concept of the nanofiber manufacturing apparatus and the nanofiber manufacturing method described as the first embodiment and the second embodiment of the present invention is that, as shown in fig. 11, a high-pressuregas ejection unit 71 is provided at the center, and a plurality ofdischarge units 73a for discharging a liquid material are disposed so as to have a variable installation angle around a high-pressure gas flow 90 ejected from the high-pressuregas ejection unit 71. That is, the supply angle θ of the liquid material with respect to the high-pressure gas flow 90 is variable. As shown in fig. 11, thedischarge unit 73a for discharging the liquid material is disposed at a supply angle θ with respect to thecenter line 91 of the high-pressure gas flow 90, and the discharged liquid material is discharged (ejected) from the plurality ofdischarge units 73a toward thecenter line 91 of the high-pressure gas flow 90 and supplied. The discharged liquid raw material discharged and supplied from the plurality ofdischarge units 73a is preferably arranged so as to intersect on thecenter line 91.

In fig. 11, the arrangement states of the respective components are as described above, and the positional relationship is as follows. When these components are expressed in terms of a positional relationship of retreating toward the downstream side with respect to the position of the gas ejection port 71 (opening nozzle) of the high-pressure gas, a is a retreating distance of the material ejection port from the gas ejection port to the ejection port of thedischarge unit 73a, b is a retreating distance of the material ejection port from the gas ejection port to a position where the discharged materials are different from each other from the ejection port of thedischarge unit 73a, c is the hole diameter of the gas ejection port, and d is the gas ejection port separation distance.

Here, the supply angle of thedischarge unit 73a for discharging the liquid material is arranged at an angle θ with respect to thecenter line 91 of the high-pressure gas flow 90

tanθ＝d/(b-a) (1)

The raw material supply tangent angle θ represented by the above formula can be adjusted within a range of 0 ° < θ < 90 °. As an example, it is preferable that the retreat distance a of the raw material discharge port is 30mm, the hole diameter c is 2mm, the gas ejection port separation distance d is 7mm, and θ is 20 ° ± 10 ° when the pressure of the high-pressure gas ejected is about 0.15 MPa.

Thus, the raw material supply tangent angle θ should be determined by the retreating distance a of the raw material discharge port, the retreating distance b of the intersecting position of the discharged raw materials, and the gas discharge port separation distance d, and further, should be determined by the relationship with the discharge port diameter c of the high-pressure gas, and the pressure and temperature of the discharged high-pressure gas.

In the nanofiber manufacturing apparatus and nanofiber manufacturing method according to the first embodiment of the present invention, a granular raw material (resin) charged into a hopper is supplied into a heating cylinder heated by a heater to be melted, and the raw material is fed to the front of the heating cylinder by a screw rotated by a motor. The heating cylinder is provided with a head portion, and high-pressure gas is ejected from a gas ejection port formed in the center of the head portion. The liquid molten material (molten resin) reaching the tip of the heating cylinder is supplied (discharged) from a supply means (discharge means) for the liquid molten material (molten resin) disposed in a plurality of extremely thin tubes located downstream of the gas discharge means through the inside of the head. The liquid molten material discharge units of the plurality of extremely thin tubes are arranged uniformly around the gas discharge port arranged at the center. Thereby, the molten resin discharged from the liquid molten material discharge means is elongated to form fibers having a diameter of nanometer order.

In the nanofiber manufacturing apparatus and nanofiber manufacturing method according to the second embodiment of the present invention, the high-pressure gas is ejected from the gas ejection port formed in the center, and the liquid raw material is ejected to the high-pressure gas from the liquid dissolved raw material discharge means of the plurality of extremely thin tubes disposed on the downstream side of the gas ejection port.

First embodiment

The overall configuration of a nanofiber manufacturing apparatus according to a first embodiment of the present invention will be described below with reference to fig. 1 to 3.

As a first embodiment of the present invention, ananofiber manufacturing apparatus 1 shown in fig. 1 includes: ahopper 2, aheating cylinder 3, aheater 4 as heating means, ascrew 5 as an extrusion device, amotor 6 as driving means, and acylindrical head 7. Thehopper 2 is used to feed a resin (particulate synthetic resin having a small particle diameter) as a raw material of nanofibers into thenanofiber manufacturing apparatus 1. Theheating cylinder 3 receives the resin supplied from thehopper 2 and heats and melts the resin. Theheater 4 heats the heating cylinder from the outside. Thescrew 5 is rotatably accommodated in theheating cylinder 3, and moves the molten resin toward the front end of theheating cylinder 3 by rotation. Themotor 6 rotates the screw 5 (details not shown) via theconnection 61. Thehead 7 is provided at the front end of theheating cylinder 3, and has a gas ejection port 71 (open nozzle) for ejecting gaseous hot air from the center, and a resin discharge means for discharging molten resin from the periphery of thegas ejection port 71. In thehead 7, high-pressure gas is supplied to thehead 7 from apipe 81 connected to thegas injection portion 8 as a gas supply pipe for injecting gas from the center. Thegas injection portion 8 is provided with heating means (not shown) such as a heater, and injects hot air from a gas injection port 71 (open nozzle). Thehead 7 and theheating cylinder 3 are connected via a sealingportion 9 such as an O-ring or an annular sheet member, and the molten resin is prevented from leaking outside the apparatus.

The plurality ofheaters 4 arranged on the outer periphery of theheating cylinder 3 are configured to be capable of temperature control independently or together by a control means not shown. In the present embodiment, as shown in fig. 1, a case where 4heaters 4 are arranged is shown, but the present invention is not limited to this, and the number ofheaters 4 to be arranged, the sizes of the heaters, and the arrangement conditions may be changed as appropriate, in accordance with various conditions such as the material and properties of the resin to be used, and the diameter and length of theheating cylinder 3.

Fig. 2 is a plan view of thenanofiber manufacturing apparatus 1 of the present embodiment, and fig. 3 is a front view. Fig. 4 to 6 are explanatory views showing the structure of thehead 7.

As shown in fig. 3, apipe 81 is connected to thehead 7 as an embodiment of the present invention, and high-pressure gas is supplied to thepipe 81 from the outer periphery of theheating cylinder 3 through thegas injection portion 8. High-pressure gas from thepipe 81 is introduced into thehead 7 and is ejected from a gas ejection port 71 (open nozzle: fig. 3) formed in the center. Around thegas ejection port 71, a plurality of resin discharge units 73 are arranged at equal intervals. In the present embodiment, the resin discharge unit 73 includes: aresin discharge needle 73a and a resin dischargeneedle mounting portion 73b, and the resin dischargeneedle mounting portion 73b has a structure in which theresin discharge needle 73a is mounted on thehead portion 7.

Thehead 7 shown in fig. 3 has: a heatingcylinder cover portion 77 that covers the front end portion of theheating cylinder 3; the resin discharge unit holdingring portion 78 serves as a means for holding the resin discharge unit 73. The resin discharge unit holdingring portion 78 is fixed to the heatingcylinder head portion 77 by a fixing means (no reference numeral) such as a bolt.

When the plurality of resin discharge units 73 are arranged around the gas ejection port 71 (open nozzle) by the resin discharge unit holdingring portion 78, the plurality of resin discharge units 73 are provided at equal intervals, at equal distances (distance a from the gas ejection port) or at equal angles (discharge angle θ), and the production amount of nanofibers having a uniform diameter and fiber length can be greatly increased.

Here, the arrangement relationship between the gas ejection ports 71 (open nozzles) and the resin discharge units 73 arranged around the gas ejection ports is described with reference to fig. 11. Thegas flow 90 is ejected from thegas ejection port 71 disposed in the center of thehead 7. A plurality of resin discharge units 73 are provided around thegas flow 90, and molten resin is discharged from the resin discharge port of theresin discharge needle 73a toward thegas flow 90 at a discharge angle θ. The resin discharge port of theresin discharge needle 73a is arranged forward (downstream along thegas flow 90 from the gas ejection port 71) by a distance a from thegas ejection port 71. The resin discharge ports of the plurality of resin discharge needles 73a discharge the discharged resin toward the front of thegas ejection port 71 by the distance b so that the discharged resin intersects the front of thegas ejection port 71 by the distance b (downstream along thegas flow 90 from the gas ejection port 71).

As the arrangement conditions of the plurality of resin ejection units 73, nanofibers having uneven diameters or fiber lengths can be formed by changing the number, arrangement interval, arrangement distance (distance a from the gas ejection port), and arrangement angle (θ) of the resin ejection units 73. Therefore, the arrangement conditions such as the arrangement interval of the resin discharge units 73 may be appropriately selected or changed according to the application of the nanofibers to be produced.

3 fig. 3 4 3 is3a 3 sectional 3view 3 taken 3 along 3 line 3a 3-3a 3 of 3 the 3head 3 7 3 of 3 fig. 3 3 3, 3 and 3 fig. 3 5 3 ( 3a 3) 3, 3 ( 3b 3) 3, 3 and 3 ( 3c 3) 3 are 3 sectional 3views 3 of 3 main 3 portions 3 ( 3 section 3b 3-3b 3, 3 section 3c 3-3c 3, 3 and 3 section 3 d 3- 3 d 3) 3 of 3 the 3head 3 7 3 of 3 fig. 3 4 3. 3 Fig. 6 is an explanatory diagram showing a flow path a of the high-pressure gas and a flow path B of the molten resin. As shown in fig. 4 to 6, 6 resin flow paths 75 (arrows B in the drawings) corresponding to the resin discharge unit 73 are formed at equal intervals inside thehead 7. The resin discharge unit 73 is connected to theheating cylinder 3 via aresin flow path 75. The molten resin extruded by the rotation of thescrew 5 flows into theresin flow path 75 shown in the D-D sectional view of (C) in fig. 5, flows into the resin discharge needle mounting portion 73B shown in the B-B sectional view through theresin flow path 75 shown in the C-C sectional view, and is discharged from theresin discharge needle 73 a. At this time, as shown in fig. 4, the gas flow path 72 (arrow a in the figure) is formed in the center of thehead 7 so as not to interfere with the resin flow path 75 (arrow B in the figure), and as shown in the C-C sectional view of fig. 5 (B), thegas flow path 72 is formed so as to change the direction from the outside of thehead 7 to the inside thereof by passing between any adjacentresin flow paths 75. Thegas piping portion 8 for supplying high-pressure gas is connected to thegas flow path 72 via apipe 81. The high-pressure and high-temperature gas supplied from thegas ejection portion 8 is ejected from the gas ejection port 71 (open nozzle) through thegas flow path 72 formed in this way. In this way, theresin flow path 75 and thegas flow path 72 are formed in thehead 7 so as not to interfere with each other. In fig. 5 (b),reference numeral 79 denotes ascrew portion 79 when the pipe (gas flow path) 81 is attached to the heatingcylinder head portion 77.

In order to adjust the arrangement condition of the resin discharge unit 73 with respect to thegas flow path 72, a holdingadjustment unit 74 of the resin discharge unit 73 is provided. However, the diameter of the resin discharge port of theresin discharge needle 73a of the resin discharge unit 73 is very thin. Therefore, theresin discharge needle 73a is very likely to be affected by the vibration of the apparatus, stress such as the pressure of the resin, and the like, and therefore, the arrangement condition of the resin discharge unit 73 may be changed or theresin discharge needle 73a may be detached from thehead 7. Therefore, there is still a need for a structure that: even if the angle of theresin discharge needle 73a is adjusted and changed, theresin discharge needle 73a is not stressed, and theresin discharge needle 73a is not detached from thehead 7.

Fig. 7(a) is an explanatory view showing a support structure constituted by a holding and adjustingunit 74, the holding and adjustingunit 74 being used for fixing the resin discharging unit 73 with respect to the resin discharging unit holdingring portion 78 and enabling adjustment of the mounting angle thereof. The resin discharge unit 73 includes aresin discharge needle 73a and a resin dischargeneedle mounting portion 73b, and the resin dischargeneedle mounting portion 73b is fixed to the resin discharge unit holdingring portion 78 of thehead portion 7 by appropriate fixing means such as screwing, engagement, and pins, which are not shown. Theresin discharge needle 73a is provided with a holding and adjustingunit 74. As shown in fig. 7, the holdingadjustment unit 74 includes: a resin dischargeneedle gripping portion 74a gripping theresin discharge needle 73a from the periphery; theadjustment unit 74b has anadjustment rod 74c that is provided so as to penetrate from the outside to the inside of thehead 7 and can advance and retreat. By operating theadjustment unit 74b to advance and retract theadjustment rod 74c, the resin dischargeneedle holding portion 74a is moved in the radial direction of thehead 7, and thereby theresin discharge needle 73a can be fixed at a desired position and angle. With the holding and adjusting means 74, the resin discharging means 73 can be adjusted so that the discharged molten resin is discharged at a desired discharge angle with respect to the flow of the gas discharged from thegas discharge port 71, and the resin discharging means 73 can be reliably fixed at the angle.

According to this configuration, the holding and adjustingunit 74 is useful as an adjusting unit for adjusting the discharge angle of the molten resin with respect to the flow of the discharged gas, and theresin discharge needle 73a has a very thin tubular shape, and the tip thereof may vibrate greatly by the driving of themotor 6 or thescrew 5 when thenanofiber manufacturing apparatus 1 is operated, but the holding and adjustingunit 74 can effectively suppress the vibration. Further, in fig. 2 of the present embodiment, a case is shown in which 6 resin discharging units 73 are provided and 6 holding and adjustingunits 74 are provided, but not limited thereto, and the number thereof may be appropriately selected depending on conditions such as the amount of resin used or the production amount, the characteristics of the product, and the like.

Fig. 7(b) shows another example of the angle adjusting function of the resin discharge unit 73. In this embodiment, the holdingadjustment unit 74 also includes: a resin dischargeneedle gripping portion 74d that grips theresin discharge needle 73a from the periphery; the adjustment unit (not shown) has anadjustment rod 74e that is provided so as to penetrate from the outside to the inside of thehead 7 and can be advanced and retracted. In this case, the adjustment unit is also operated to advance and retreat theadjustment rod 74e and move the resin dischargeneedle holding portion 74d in the radial direction of thehead portion 7, thereby fixing theresin discharge needle 73a at a desired position and angle. In this case, the resin dischargeneedle attachment portion 73c is spherical or cylindrical, the slidingsurface 76 on which the resin dischargeneedle attachment portion 73c is rotatable and revolves is formed on the resin discharge unit holdingring portion 78 of thehead portion 7, and the angle of theresin discharge needle 73a can be easily adjusted by attaching the resin dischargeneedle attachment portion 73 c. This allows the resin ejection unit 73 to be angularly adjusted without fear of theresin ejection needle 73a falling off.

Further, as shown in the drawing, thegas ejection port 71 and the resin discharge unit 73 are configured as follows: the resin discharge unit 73 is located downstream of thegas ejection port 71. With this configuration, the molten resin gradually expands along the distribution of the jet gas flow of the gas jetted from thegas jetting port 71, and becomes a fiber shape having a diameter of nanometer order. Further, since the gas serving as hot air is ejected from thegas ejection portion 8 by a heating means not shown, the resin discharged from the resin discharge unit 73 can be made into finer nanofibers having longer fiber diameters than in the case of ejecting normal temperature gas.

A series of operations of thenanofiber manufacturing apparatus 1 having the above-described configuration will be described. The raw material (resin) charged into thehopper 2 is heated and melted by theheater 4 in theheating cylinder 3, and is discharged to the front of theheating cylinder 3 by a screw rotated by themotor 6. The molten resin reaching the distal end of theheating cylinder 3 passes through 6resin flow paths 75 formed inside thehead 7 and is discharged from the material discharge ports of the 6 resin discharge needles 73 a. The discharged molten resin is carried while being moved by a gas flow generated by the high-pressure and high-temperature gas supplied from thegas jetting portion 8 and jetted from thegas jetting port 71. At this time, the molten resin is extended to form nanofibers due to the difference between the flow of the high-temperature gas having a faster velocity and the velocity of the air staying around the molten resin having a slower velocity.

Second embodiment

As the first embodiment of the present invention, a nanofiber manufacturing apparatus in which a particulate synthetic resin having a fine particle diameter is melted and used as a raw material has been described in detail, but as described above, a liquid raw material of nanofibers is not limited to this, and a dissolved raw material in which a solid raw material or a liquid raw material is dissolved in a predetermined solvent in advance to have a predetermined concentration may be used. This is also a liquid raw material. Fig. 8 to 10 show a nanofiber manufacturing apparatus for forming nanofibers from a dissolved raw material. Note that the same structures as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

In the second embodiment of the present invention, asolvent storage 5A having a function of pressing a dissolved material by applying a predetermined pressure is used instead of thehopper 2, thescrew 5, and themotor 6 of the first embodiment. The predetermined pressure may be a pressure generated by gravity due to a difference in level. Thehead 7A is connected to asolvent supply hose 3A and agas ejection unit 8. Although not shown, means for ejecting gas may be appropriately disposed in thegas ejecting portion 8 or may be introduced from a high-pressure gas supply portion (not shown) into thegas ejecting portion 8. As shown in fig. 9, thehead portion 7A is provided with agas passage 72A and agas ejection port 71A constituting a passage for the gas supplied from thegas ejection portion 8. Similarly, thehead 7A is provided with aresin flow path 75A as a flow path for dissolving the raw material, and theresin flow path 75A is connected to the resin discharge unit 73. The resin discharge unit 73 has a structure including aresin discharge needle 73a as a discharge port for dissolving the raw material, and a resin discharge needle mounting portion not shown in fig. 8 to 10, as in the first embodiment. Further, thehead portion 7A is provided with a resin discharge unit holdingplate portion 78A, and by providing a holdingadjustment unit 74 thereon, the discharge angle of theresin discharge needle 73a can be freely adjusted by the holdingadjustment unit 74 as in the first embodiment, wherein the holdingadjustment unit 74 includes: a resindischarge needle grip 74 a; and anadjusting unit 74b having an adjustingrod 74c that is provided so as to penetrate from the outside to the inside of thehead portion 7A and can advance and retreat.

As shown in fig. 10, the nanofiber manufacturing apparatus of the second embodiment is provided with 2 resin discharge units 73. Of course, the arrangement of the resin discharge units 73 is not limited to 2, and 3 or more resin discharge units 73 may be provided around thegas ejection port 71A. At this time, the resin discharge units 73 are preferably uniformly provided. Although the embodiment shown in the drawings shows a horizontal discharge type gas discharge system, a modification in which thegas flow path 72A from thegas discharge port 71A discharges gas vertically (from above to below or from below to above) is also conceivable to those skilled in the art.

With this configuration, compared to the configuration of the first embodiment, by using a dissolving raw material in which the raw material is dissolved in a solvent, the nanofiber manufacturing apparatus can be configured without using a complicated apparatus such as a heating cylinder, a motor, or a screw, and thus the apparatus can be downsized and the space can be saved. Further, the apparatus can be made smaller, and thus a portable nanofiber manufacturing apparatus can be made. In such a portable nanofiber manufacturing apparatus, nanofibers can be formed by spraying nanofibers onto a place where nanofibers are to be attached, and the application of nanofibers is expanded.

While the embodiments of the present invention have been described in detail, the present invention is not limited to the embodiments, and various modifications can be made within the spirit and scope of the present invention. For example, although the above embodiment shows the transverse nanofiber manufacturing apparatus in which the molten resin and gas ejection ports are directed in the horizontal direction, the present invention is not limited thereto, and the longitudinal nanofiber manufacturing apparatus and manufacturing method in which the molten resin and gas ejection ports are directed downward are also free from any problem. This effectively avoids the influence of gravity. Further, although the extrusion apparatus has been described as thescrew 5, it is necessary to cope with a method of interrupting the production of nanofibers, but there is no problem in that the solution is supplied sequentially and extruded intermittently by using a piston or the like as in the case of die casting. Further, thegas ejection port 71 may be formed in a conical shape as a nozzle shape to increase the pressure. Further, although 2 specific examples have been described as the structure for adjusting the angle of theresin ejection needle 73a, any configuration may be used as long as it can adjust the angle of, for example, a bellows-type resin ejection means.

Description of the reference numerals

1 nanofiber manufacturing apparatus

2 hopper

3 heating cylinder

4 Heater (heating unit)

Screw 5 (extrusion device)

6 Motor (drive unit)

7 head part

71 gas outlet (high pressure gas outlet unit)

72 gas flow path

73 resin discharge unit

73a resin discharge needle (Material discharge port)

73b, 73c resin discharge needle mounting part

74 holding adjustment unit

74a resin discharge needle holding part

74b adjusting part

74c adjusting rod

75 resin flow path

76 sliding surface

77 heating cylinder cover

78 resin discharge unit holding ring portion

8 gas injection part (gas injection unit)

81 tubes (gas flow path)

90 flow of gas

91 center line of high pressure gas flow.

Claims (3)

1. A nanofiber manufacturing apparatus having a resin discharge unit that discharges molten resin to a high-pressure gas flow discharged from a high-pressure gas discharge unit, the nanofiber manufacturing apparatus being characterized in that,

comprising:

a hopper for charging a resin as a raw material of the nanofibers,

a heating cylinder for receiving the resin supplied from the hopper and heating and melting the resin,

a heater as a heating means for heating the heating cylinder,

a screw, as an extrusion device, rotatably housed in the heating cylinder and rotating to move the molten resin toward a tip end of the heating cylinder,

a motor as a driving unit for rotating the screw,

a head part provided at the front end of the heating cylinder, having a high-pressure gas flow path formed in the center and a plurality of molten resin flow paths formed in the periphery,

a gas supply pipe for supplying high-pressure gas to the flow path of the high-pressure gas formed in the center of the head part,

an angle adjusting unit capable of adjusting an installation angle of the resin discharging unit with respect to a high-pressure gas flow discharged from the high-pressure gas discharging unit;

the high-pressure gas from the gas supply pipe is introduced into the head portion from the outer periphery and is ejected from the high-pressure gas ejection means formed in the center portion, the resin ejection means is arranged in a plurality of equally spaced positions around the high-pressure gas ejection means with the high-pressure gas flow ejected from the high-pressure gas ejection means as the center, and the discharged liquid material to be discharged and supplied is arranged at an installation angle of more than 0 ° and less than 90 ° with respect to the center line of the high-pressure gas flow so as to intersect the center line of the high-pressure gas flow.

2. A nanofiber manufacturing method using a nanofiber manufacturing apparatus, the nanofiber manufacturing apparatus comprising:

a hopper for charging a resin as a raw material of the nanofibers,

a heating cylinder to which the resin is supplied from the hopper,

a heating unit for heating the heating cylinder,

a screw as an extruding device for extruding the raw material in the heating cylinder,

a motor as a driving unit for rotating the screw,

a head part provided at the front end of the heating cylinder, having a high-pressure gas flow path formed in the center and a plurality of molten resin flow paths formed in the periphery,

a gas supply pipe for supplying high-pressure gas to the flow path of the high-pressure gas formed in the center of the head part,

an angle adjusting unit capable of adjusting a setting angle of the resin discharging unit with respect to a high-pressure gas flow discharged from the high-pressure gas discharging unit;

the nanofiber manufacturing method is characterized in that,

high-pressure gas from the gas supply pipe is introduced into the head portion from the outer periphery and is ejected from the high-pressure gas ejection unit formed in the center portion,

a plurality of resin discharging means for discharging the resin in a molten state in the heating cylinder are provided around the high-pressure gas ejecting means,

heating the heating cylinder by the heating means to melt the supplied resin in the heating cylinder, and discharging the resin from the resin discharge means by the extrusion device so that the discharged liquid material discharged and supplied intersects the center line of the high-pressure gas flow and the discharge angle of the liquid material with respect to the center line of the high-pressure gas flow is in the range of more than 0 ° and less than 90 °,

the gas ejected from the high-pressure gas ejection means generates a gas flow, and the discharged liquid raw material that is discharged and supplied is moved from the outer periphery along the gas flow of the ejected gas so as to intersect on the center line of the high-pressure gas flow, whereby the discharged liquid raw material is elongated and formed into fibers having a nanometer-scale diameter.

3. The nanofiber manufacturing method according to claim 2, wherein, when discharging the liquid raw material, the liquid raw material is discharged from the resin discharge unit so that a discharge angle of the liquid raw material with respect to the high-pressure gas flow is adjusted within a range of more than 0 ° and less than 90 °.

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