KR102691162B1 - Two-component material mixing electrospinning device - Google Patents

Abstract

The present invention produces a spinning mixture by uniformly mixing the first mixture (thermosetting resin, thermoplastic resin polymerization material) and the second mixture (thermosetting resin curing agent, thermoplastic resin polymerization catalyst/initiator) at a set ratio without using any toxic solvents. After electrospinning, a non-toxic nanofiber membrane is produced. Therefore, in order to manufacture a conventional nanofiber membrane, various problems arising from having to dissolve a high molecular weight thermoplastic resin in a toxic organic solvent can be solved.

Description

Two-component material mixing electrospinning device}

The present invention relates to a two-component mixing electrospinning device.

Electrospinning is a method of producing nanofibers or nanofiber membranes by spraying a polymer solution dissolved in an electric field.

To manufacture a nanofiber membrane by electrospinning, a polymer solution is forced to flow through a syringe pump to form polymer droplets at the end of the nozzle, and a high voltage potential is applied to induce free charges in the polymer solution, thereby creating a repulsion force of the free charges. This causes the solution to overcome surface tension and erupt.

Most nanofiber membrane manufacturing methods using electrospinning use a method of dissolving pure low-molecular-weight thermoplastic polymer resin in advance in a solvent to create a solution with a certain concentration, and then applying high voltage to the outside for spinning.

However, it is difficult to manufacture nanoscale nanofiber membranes with low molecular weight thermoplastic resins. To solve this problem, a high molecular weight thermoplastic resin can be used, but in this case, a toxic organic solvent is needed to dissolve the high molecular weight thermoplastic resin. These toxic organic solvents remain in the nanofiber membrane after its manufacture.

The electrospinning method of producing a nanofiber membrane using a high molecular weight thermoplastic resin causes problems between the producer and the manufacturer during the process of manufacturing a product using the manufactured nanofiber membrane due to the toxic organic solvent. , causing harm to consumers during the process of using the product. Additionally, due to the toxic organic solvent remaining in the nanofiber membrane, the nanofiber membrane melts or deforms, thereby deteriorating the mechanical properties of the nanofiber membrane.

Additionally, when manufacturing a nanofiber membrane by melt spinning, it is difficult to add a conductive filler due to the high viscosity of the thermoplastic material during the melting process of the high molecular weight thermoplastic resin. Because of this, it is difficult to improve the mechanical, thermal, and electrical properties of the nanofiber membrane by including conductive fillers.

Korean registered patent (10-2275832)

The purpose of the present invention is to provide a two-component mixing electrospinning device that can solve the above-mentioned problems.

The two-component mixing electrospinning device to achieve the above purpose is,

A first supply unit supplying the first mixture;

A second supply unit supplying the second mixture;

A set amount of the first mixture is supplied from the first supply unit, and a set amount of the second mixture is supplied from the second supply unit, and the first mixture and the second mixture are uniformly mixed at a set ratio. A mixing unit that produces a spinning mixture;

a spinning unit that receives the spinning mixture from the mixing unit and performs electrospinning to produce a nanofiber membrane; and

It is characterized in that it includes a cleaning unit for cleaning the mixing unit and the radiation unit.

In addition, the above purpose is to

A first supply unit supplying the first mixture;

A second supply unit supplying the second mixture;

A set amount of the first mixture is supplied from the first supply unit, and a set amount of the second mixture is supplied from the second supply unit, and the first mixture and the second mixture are uniformly mixed at a set ratio. A mixing unit that produces a spinning mixture;

a spinning unit that receives the spinning mixture from the mixing unit and performs electrospinning to produce a nanofiber membrane; and

It includes a cleaning unit for cleaning the mixing unit and the radiation unit,

The mixing unit is,

A body provided with an inlet at the top through which the first mixture or the second mixture flows;

A piston is installed inside the body to be rotatable or movable up and down, and is composed of a head and a rod, with a discharge hole penetrating from the top surface to the bottom surface formed at the center, and a plurality of stirring blades installed on the upper surface of the head;

A piston rotating unit consisting of a rotor surrounding the outer peripheral surface of the rod and a stator installed on the inner peripheral surface of the body at a position facing the rotor to rotate the piston;

A piston upper and lower part consisting of a permanent magnet installed on the lower surface of the head and surrounding the rod to move the piston up and down, and an electromagnet located below the permanent magnet and installed on the inner peripheral surface of the body; and

This is achieved by a two-component mixing electrospinning device, which is installed inside the body and includes a heat source that supplies heat to the piston.

The present invention produces a spinning mixture by uniformly mixing the first mixture (thermosetting resin, thermoplastic resin polymerization material) and the second mixture (thermosetting resin curing agent, thermoplastic resin polymerization catalyst/initiator) at a set ratio without using any toxic solvents. After electrospinning, a non-toxic nanofiber membrane is produced. Therefore, in order to manufacture a conventional nanofiber membrane, various problems arising from having to dissolve a high molecular weight thermoplastic resin in a toxic organic solvent can be solved.

In the present invention, a nanofiber membrane with controlled and improved mechanical, thermal, and electrical properties is manufactured by including a conductive filler in the first mixture (thermosetting resin, thermoplastic resin polymer). Therefore, when manufacturing a nanofiber membrane by melt spinning, the problem of difficulty in adding a conductive filler due to the high viscosity of the thermoplastic material during the melting process of the high molecular weight thermoplastic resin can be solved.

Figure 1 is a diagram showing a two-component mixing electrospinning device according to an embodiment of the present invention.
Figure 2 is a diagram showing a state in which the third supply unit is connected to the first supply unit shown in Figure 1.
Figure 3 is an enlarged view of the mixing unit shown in Figure 1, showing a state in which the piston rotates.
Figure 4 is an enlarged view of the mixing unit shown in Figure 1, showing a state in which the piston is rising.
Figure 5 is a diagram showing a state in which a spinning unit produces a nanofiber membrane by spinning a spinning mixture.
Figure 6 is a diagram showing a state in which the cleaning unit cleans the mixing unit and the spinning unit with a cleaning solution.

Hereinafter, a manufacturing device for a two-component mixed electrospinning device according to one embodiment of the present invention will be described in detail.

As shown in Figure 1, the two-component mixing electrospinning device 1 according to an embodiment of the present invention includes a first supply unit 10, a second supply unit 20, a mixing unit 30, and spinning. It consists of a unit 40 and a cleaning unit 50. And, it is composed of various parts such as the frame on which they are installed, the control unit that controls them, wiring, wires, power sources, and pneumatics. Hereinafter, only the essential parts will be described so as not to distract from the gist of the invention.

[First supply unit (10)]

The first supply unit (10) includes a first tank (11), a first agitator (12), a first deaerator (13), a first recovery device (14), a first heat source (15), and a first pump (16). , It consists of a first flow meter (17) and a first opening/closing valve (18).

The first tank 11 stores the first mixture.

The first mixture is a thermosetting resin or thermoplastic resin polymer.

In this embodiment, bisphenol A type epoxy resin or bisphenol F type epoxy resin is used as the thermosetting resin. Bisphenol A type and F type epoxy resin can be selected according to the characteristics of the nanofiber membrane.

In this example, caprolactam, a polyamide intermediate, is used as a thermoplastic resin polymerization material.

Meanwhile, additional conductive fillers may be added to the first mixture. To this end, as shown in FIG. 2, a third supply unit 60 is added and connected to the first supply unit 10 through a pipe L61. The third supply unit (60) includes a fourth tank (61) into which the first mixture and the conductive filler are mixed, and an ultrasonic vibrator (62) that excites the fourth tank (61) to evenly mix the first mixture and the conductive filler. ) is provided. The third supply unit 60 mixes the first mixture with a conductive filler and supplies it to the first supply unit 10 in a set amount. For this purpose, a supply pump 63 and a flow meter 64 are installed in the pipe L61.

The conductive filler may be any one of graphite powder, graphene, carbon nanotubes, or a mixture thereof. Graphite powder, graphene, and carbon nanotubes can improve the conductivity and strength of nanofiber membranes. In addition, graphite powder, graphene, and carbon nanotubes have self-lubricating properties and are resistant to friction, which can improve the wear resistance of nanofiber membranes.

By mixing the first mixture with the conductive filler, the mechanical, thermal, and electrical properties of the nanofiber membrane can be adjusted and improved.

The first agitator 12 includes a propeller 121 installed inside the first tank 11, a motor 122 installed on the top of the first tank 11 to rotate the propeller 121, and the motor 122. It consists of a connecting shaft 123 connecting the shaft and the propeller 121.

The first stirrer 12 stirs the first mixture by rotating the propeller 111 at a speed of about 100 to 300 rpm so that the temperature of the first mixture is uniform.

The first defoamer 13 communicates with the inside of the first tank 11 through a pipe L11, and removes air bubbles in the first tank 11 by sucking them in using vacuum pressure.

The first recovery device 14 is installed on the pipe L12 connecting the first tank 11 and the mixing unit 30, and recovers the first mixture remaining in the mixing unit 30 to the first tank 11. do.

The first heat source 15 continuously supplies heat to the inside of the first tank 11 so that the temperature of the first mixture is maintained at a temperature (30 to 150°C) suitable for electrospinning. The first heat source 15 may be configured in various ways, such as a heating wire or a planar heating element.

The first pump 16 supplies a set amount of the first mixture to the mixing unit 30 through the pipe L13.

The first flow meter 17 measures the flow rate of the first mixture flowing in the pipe L13. The first pump 16 receives flow rate feedback from the first flow meter 17 and adjusts the flow rate of the first mixture to the set flow rate.

The first on/off valve 18 is installed in the pipe L13 and supplies the first mixture to the mixing unit 30 or blocks the supply.

[Second supply unit (20)]

The second supply unit (20) includes a second tank (21), a second agitator (22), a second deaerator (23), a second recovery device (24), a second heat source (25), and a second pump (26). , It consists of a second flow meter (27) and a second opening/closing valve (28).

The second tank 21 stores the second mixture.

The second mixture is a thermosetting resin hardener when the first mixture is a thermosetting resin. In this example, a second mixture of amines is used as a thermosetting resin hardener.

The second mixture is a thermoplastic resin polymerization catalyst/initiator when the first mixture is a thermoplastic resin polymerization material. In this example, sodium ε-caprolactamate is used as a catalyst, and an isocyanate compound or an ester compound is used as an initiator.

The second stirrer 22 stirs the second mixture. The second agitator 22 includes a propeller 221 installed inside the second tank 21, a motor 222 installed on the upper part of the second tank 21 to rotate the propeller 221, and the motor 222. It consists of a connecting shaft 223 that connects the shaft and the propeller 221.

The second agitator 22 stirs the second mixture by rotating the propeller 221 at a speed of about 100 to 300 rpm so that the temperature of the second mixture is uniform.

The second deaerator 23 communicates with the inside of the second tank 21 through a pipe L21, and removes air bubbles in the second tank 21 by sucking them in using vacuum pressure.

The second recovery device (24) is installed on the pipe (L22) connecting the second tank (21) and the mixing unit (30) to recover the second mixture remaining in the mixing unit (30) to the second tank (21). do.

The second heat source 25 continuously supplies heat to the inside of the second tank 21 so that the temperature of the second mixture is maintained at a temperature (30 to 150°C) suitable for electrospinning. The first heat source 15 may be configured in various ways, such as a heating wire or a planar heating element.

The second pump 26 supplies a set amount of the second mixture to the mixing unit 30 through the pipe L23.

The second flow meter 27 measures the flow rate of the second mixture flowing in the pipe L23. The second pump 26 receives flow rate feedback from the second flow meter 27 and adjusts the flow rate of the second mixture to the set flow rate.

The second on/off valve 28 is installed in the pipe L23 and supplies the second mixture to the mixing unit 30 or blocks the supply.

[Mixed Unit (30)]

Referring to Figures 3 and 4, the mixing unit 30 consists of a body 31, a piston 32, a piston rotating part 33, a piston upper/lower part 34, and a heat source 25.

The upper part of the body 31 is provided with an inlet 31a through which the first mixture or the second mixture flows. An insulating cylinder 31b is installed at the lower end of the body 31. The insulating cylinder 31b surrounds the rod 32b. The insulating cylinder 31b is made of a ceramic insulator or a non-ceramic insulator that does not conduct electricity. The insulating cylinder 31b prevents high voltage from being applied to the body 31 when high voltage is applied to the radiation unit 40.

The piston 32 is installed inside the body 31 so that it can rotate or move up and down. The piston 32 consists of a head 32a and a rod 32b whose diameter is smaller than that of the head 32a.

A discharge hole 32c is formed at the center of the piston 32. The discharge hole 32c penetrates from the top surface to the bottom surface of the piston 32. A plurality of stirring blades (32d) are installed on the upper surface of the head (32a).

A space where the first mixture and the second mixture are mixed is formed by the upper side of the head 32a and the inner wall of the body 31. This is called mixed space (S). In addition, the mixture of the first mixture and the second mixture is collectively referred to as “spinning mixture.” A seal (not shown) is installed between the side of the head 32a and the body 31 to prevent the radiation mixture from leaking.

Piston rotating part (33)

Referring to Figure 3, the piston rotating unit 33 rotates the piston 32.

The piston rotating part 33 consists of a rotor 33a surrounding the outer peripheral surface of the rod 32b, and a stator 33b installed on the inner peripheral surface of the body 31 at a position facing the rotor 33a. The rotor 33a is composed of permanent magnets, and the stator 33b is composed of coils 33bb. When a current is applied to the coil, a magnetic field is formed around the coil, and the magnetic force of this magnetic field and the magnetic force of the permanent magnet repel each other, causing the rod 32b to rotate. The rotational speed of the load 32b is adjusted according to the intensity of the current applied to the coil. Since this is a technology known to be the same as the motor operating principle, further detailed description will be omitted.

When the piston 32 rotates, the stirring blade 32d rotates, and the radiation mixture remaining in the mixing space S is stirred by the stirring blade 32d. In this way, by stirring the spinning mixture once again just before electrospinning, a nanofiber membrane with uniform physical properties can be manufactured.

Piston upper and lower part (34)

Referring to Figure 4, the piston upper and lower part 34 moves the piston 32 up and down.

The piston upper and lower part 34 is installed on the lower surface of the head 32a and includes a permanent magnet 34a surrounding the rod 32b, and an electromagnet 34b located below the permanent magnet 34a and installed on the inner peripheral surface of the body 31. It consists of The electromagnet 34b generates an opposite polarity to the permanent magnet 34a. The electromagnet 34b consists of an iron core (not shown) and a coil 34bb wound around the iron core. Since the operating principle of an electromagnet is a known technology, further detailed description will be omitted.

The speed at which the piston 32 rises or falls can be controlled by adjusting the strength of the current applied to the electromagnet 34b. In other words, it can be controlled by adjusting the downward force caused by the self-weight of the piston 32 and the repulsive force of the permanent magnet 34a and the electromagnet 34b.

When the piston 32 rises, the volume of the mixing space S decreases, and the radiation mixture remaining in the mixing space S moves to the radiation unit 40 through the discharge hole 32c.

Heat source (35)

The heat source 35 is installed on the lower inner peripheral surface of the body 31. The heat source 35 continuously supplies heat to the outer peripheral surface of the piston 32 so that the temperature of the spinning mixture is maintained at a temperature (30 to 150° C.) suitable for electrospinning. Due to this, the spinning mixture flowing through the discharge hole 32c of the piston 32 is maintained at a temperature suitable for electrospinning. The heat source 35 may be configured in various ways, such as a heating wire or a planar heating element.

In addition, the mixing unit 30 can be configured in various ways using known technologies such as electronic and mechano-electronic mixing. In addition, in the two-component mixing electrospinning device, only the mixing unit 30 can be replaced with a different type of mixing unit, resulting in excellent compatibility. For example, the mixing unit 30 can be easily replaced with a known mixing head as needed.

[radiation unit (40)]

The radiation unit 40 consists of a nozzle 41, a voltage unit 42, and a collection unit 43.

The nozzle 41 is installed at the lower end of the insulating cylinder 31b.

The voltage unit 42 applies high voltage to the nozzle 41 for electrospinning. The + pole of the voltage part 42 is connected to the side of the nozzle 41, and the - pole is connected to the collection part 43.

The collection unit 43 collects the electrospun nanofiber membrane. The collection unit 43 is composed of a cylindrical body 43a and a motor 43b that rotates the cylindrical body 43a. While the cylindrical body 43a rotates, the electrospun nanofiber membrane is wound around the cylindrical body 43a. The -pole of the voltage portion 42 is connected to the axis supporting the cylindrical body 43a.

A third heat source 45 is located on the lower side of the cylindrical body 43a to maintain the cylindrical body 43a at a set temperature (30 to 120°C) so that the nanofiber membrane wound around the cylindrical body 43a can be hardened. . The third heat source 45 can be configured in various ways, such as a heating wire or a planar heating element.

The collecting unit 43 and the third heat source 45 are installed on the moving member (L). The moving member (L) can be moved left and right by the driving means (M). The driving means (M) may be composed of known technologies such as a ball screw type or a linear motor type.

[Cleaning unit (50)]

The cleaning unit 50 cleans the mixing unit 30 and the radiation unit 40.

The cleaning unit 50 consists of a third tank 51, a third pump 52, a third flow meter 53, a third open/close valve 54, and a cleaning liquid collection container 55.

The third tank 51 stores cleaning liquid. In this example, acetone is used as a cleaning solution.

The third pump 52 supplies a set amount of cleaning liquid to the mixing unit 30 through the pipe L51.

The third flow meter 53 measures the flow rate of the cleaning liquid flowing in the pipe L51. The third pump 52 receives flow rate feedback from the third flow meter 53 and adjusts the flow rate of the cleaning liquid to the set flow rate.

The third on/off valve 54 is installed in the pipe L51 to supply or block the supply of the cleaning liquid to the mixing unit 30.

The cleaning liquid collection container 55 cleans the mixing unit 30 and the spinning unit 40 and collects the remaining cleaning liquid.

The cleaning liquid collection container 55 is installed on the moving member L on which the collection unit 43 is installed. The cleaning liquid collection container 55 is located at a certain interval in the lateral direction of the collection unit 43. When the moving member (L) moves, the collection unit (43), the third heat source (45), and the cleaning liquid collection container (55) move together.

Hereinafter, the operation of the two-component mixing electrospinning device according to an embodiment of the present invention will be described. Basically refer to Figures 1 to 3.

electrospinning

Referring to Figure 5, the first supply unit 10 supplies the first mixture to the mixing unit 30. The second supply unit 20 supplies the second mixture to the mixing unit 30. In this case, the first on-off valve 18 and the second on-off valve 28 are opened, and the third on-off valve 54 is closed.

The mixing ratio of the first mixture and the second mixture is controlled by the discharge amount of the first pump (16) and the discharge amount of the second pump (26). In addition, the overall physical properties of the nanofiber membrane are adjusted depending on the amount of conductive filler added to the first mixture and the degree of dispersion. Additionally, if the first mixture is a thermosetting resin, the curing time can be adjusted by additionally adding a curing accelerator or curing retardant to the first tank 11.

The first mixture and the second mixture are mixed within the mixing space (S) to create a spinning mixture. The stirring blade (32d) rotates to stir the spinning mixture. The piston (32) rises. As the volume of the mixing space (S) decreases, the spinning mixture remaining in the mixing space (S) moves to the spinning unit (40) through the discharge hole (32c). The spinning mixture is deposited at the end of the nozzle (41). A high voltage of 16kV is applied to the nozzle (41). The radiation mixture is radiated. A nanofiber membrane is created from the spinning mixture and wound around the cylindrical body (43a). The nanofiber membrane is hardened by the heat of the third heat source 45.

sejung

When the first mixture is exhausted in the first supply unit 10 or the second mixture is exhausted in the second supply unit 20, electrospinning is stopped.

After electrospinning is stopped, when the first mixture or the second mixture is replenished, the cleaning unit 50 cleans the mixing unit 30 and the spinning unit 40. In this case, the first on-off valve 18 and the second on-off valve 28 are closed, and the third on-off valve 54 is open.

Referring to FIG. 6, the cleaning unit 50 supplies cleaning liquid to the mixing unit 30.

The moving member (L) is moved to the left by the driving means (M), and the cleaning liquid collection container (55) instead of the cylindrical body (43a) is positioned below the nozzle (41).

The piston (32) rises. As the volume of the mixing space (S) decreases, the cleaning liquid remaining in the mixing space (S) moves to the radiation unit (40) through the discharge hole (32c). The spinning mixture is sprayed into the cleaning liquid collection container (55) through the nozzle (41). While the cleaning liquid is sprayed, the mixing space (S), discharge hole (32c), and nozzle (41) are cleaned.

In this way, when the first mixture or the second mixture is replenished after electrospinning is stopped, the mixing space (S), the discharge hole (32c), and the nozzle (41) are cleaned, so the first mixture or the second mixture is replenished. Once this is completed, electrospinning can be resumed immediately. Therefore, the present invention is suitable for mass production of nanofiber membranes, not for experimental production of nanofiber membranes.

1: Two-component mixing electrospinning device
10: first supply unit 20: second supply unit
30: mixing unit 40: radiation unit
50: cleaning unit 60: third supply unit

Claims (5)

A first supply unit supplying the first mixture;
A second supply unit supplying the second mixture;
A set amount of the first mixture is supplied from the first supply unit, and a set amount of the second mixture is supplied from the second supply unit, and the first mixture and the second mixture are uniformly mixed at a set ratio. A mixing unit that produces a spinning mixture;
a spinning unit that receives the spinning mixture from the mixing unit and performs electrospinning to produce a nanofiber membrane; and
It includes a cleaning unit for cleaning the mixing unit and the radiation unit,

The mixing unit is,
A body having an inlet at the top through which the first mixture or the second mixture flows, and an insulating cylinder installed at the lower end;
A piston is installed inside the body to be rotatable or movable up and down, and is composed of a head and a rod, with a discharge hole penetrating from the top surface to the bottom surface formed at the center, and a plurality of stirring blades installed on the top surface of the head;
A piston rotating unit consisting of a rotor surrounding the outer peripheral surface of the rod and a stator installed on the inner peripheral surface of the body at a position facing the rotor to rotate the piston;
A piston upper and lower part consisting of a permanent magnet installed on the lower surface of the head and surrounding the rod to move the piston up and down, and an electromagnet located below the permanent magnet and installed on the inner peripheral surface of the body; and
It includes a heat source installed inside the body to supply heat to the piston,

The radiation unit is,
a nozzle directly connected to the bottom of the insulating cylinder;
A voltage unit that applies high voltage for electrospinning to the nozzle; and
A two-component mixed electrospinning device characterized by consisting of a collection unit that collects the electrospun nanofiber membrane. The two-component mixed electrospinning device according to claim 1, wherein the first mixture is a thermosetting resin, and the second mixture is a thermosetting resin curing agent. The two-component mixed electrospinning device according to claim 1, wherein the first mixture is a thermoplastic resin polymerization material, and the second mixture is a thermoplastic resin polymerization catalyst/initiator. The method of claim 1, wherein a conductive filler is added to the first mixture,
A two-component mixed electrospinning device, wherein the conductive filler is one of graphite powder, graphene, and carbon nanotubes, or a mixture thereof. delete