CN103484953A - Disc-type needle-free electrostatic spinning device - Google Patents

Abstract

The invention discloses a needle-free electrospinning device capable of continuously producing nanofiber membranes on a large scale, and provides an electrospinning technology that can effectively improve the yield and uniformity of electrospinning. The main points of the technical scheme are: using a disc with a special structure as the spinning unit, and applying voltage to each spinning unit through the PTFE shaft with built-in wires, so that the electric field between the spinning units is more uniform; The adjustable arc-shaped PTFE shield controls the amount of liquid at the spinning point, making the nanofiber fineness uniform and saving electric energy. The feature of the present invention is that the PTFE rotating shaft with built-in wires, the special disc structure, and the highly controllable arc-shaped PTFE shielding cover can make the electric field distribution among the spinning units uniform and effectively improve the nanometer Uniformity of fiber fineness and output in the fiber membrane, while avoiding the shortcomings of traditional needle equipment such as uneven power plant, easy blockage of needles, and difficulty in cleaning; the use of a disc-type needle-free electrospinning device effectively improves production capacity and The uniformity can reduce the cost, which is beneficial to the industrialization of electrospinning technology.

Description

A disc-type needle-free electrospinning device

technical field

The invention relates to an electrospinning technology, in particular to a disc-type needle-free electrospinning device.

technical background

Electrospinning is a method that uses electrostatic field force to draw spinning jet to form nanofiber nonwovens; as the most commonly used nanofiber production method, this technology has been extensively studied in recent years, and it has cost Low, simple, and applicable to most polymers and other advantages. Its products are fibers with a fineness between nanometers and micrometers, and are deposited on the receiving device in a disordered manner to form a micro-nano fiber web/film similar to non-woven fabrics, which can be used for filter materials, biomedical materials, and chemical sensors. , Multiple high-tech fields of battery separators.

Electrospinning technology, as the most effective method for continuous preparation of polymer nanofibers, has many advantages, but it is difficult to achieve large-scale production. At present, large-scale electrospinning technology is divided into two categories, one is multi-needle electrospinning technology, represented by Freudenburg Nonwovens in Germany, Finetex Technology Inc. in the United States, eSpinTechnologies, NanoMatrix, TOPTECH in South Korea, etc.; The category is needle-free electrospinning technology, and the representative companies are Donaldson Company of the United States and Elmarco Company of the Czech Republic (nano spider). Existing multi-needle electrospinning equipment has problems such as easy needle blockage, low efficiency and low output, serious electric field interference between multiple jets (End effect phenomenon), and uneven lateral thickness of electrospun membranes; existing needle-free electrospinning equipment (nano Spider) Although there is no needle clogging problem in traditional electrospinning, and the output is much higher than that of the needle-type electrospinning device, there are problems such as uneven thickness of the obtained fibers, thick fibers, high energy consumption, and difficult control of product quality.

Contents of the invention

Aiming at the shortcomings of the existing large-scale electrospinning equipment, the technical solution proposed by the present invention is to design a disc-type needle-free electrospinning device. The device includes an inner wall solution pool, which can save electricity and prevent leakage; it adopts a disc-type spinning head, which can evenly mix the spinning solution and control the fiber fineness; it also includes a high-performance plastic shaft with built-in wires, Voltage can be applied to each spinning disc separately, saving electric energy and reducing electric field interference; the device is specially designed with an arc-shaped shielding cover, which can control the solution thickness at the spinning position, make the nanofiber fineness uniform, and save electric energy .

The technical scheme of the present invention to solve the problem of large-scale electrospinning equipment is to design a disc-type needle-free large-scale electrospinning nanofiber non-woven fabric production equipment, which mainly includes: a solution pool 55, a high-performance plastic shaft 85, Spinning disc 80, shielding cover 75, high-voltage power supply 10, net transmission curtain 15, grounding target electrode plate 40, air suction device 35, transmission device 25, anti-slip device 50, etc.

The inner wall layer of the solution pool 55 is composed of high-performance plastics, which has the functions of saving electric energy and preventing leakage; the solution pool 55 adopts an arc-shaped design, and its inner diameter is slightly larger than the diameter of the spinning disc 80, which has the advantages of saving raw materials and uniform solution Function: According to the output of the equipment, the difference between the injection pump 120 and the return pump 125 can be controlled, the solution content in the solution pool can be precisely controlled, and the solution can flow with it to prevent polymer deposition.

The high-performance plastic rotating shaft adopts a polytetrafluoroethylene, polyphenylene sulfide or polypropylene plastic central shaft 85, and wires 95 for applying different voltages to each turntable are arranged on the central shaft, and the wires are covered by high-performance plastic tubes. It can save electricity and prevent the danger of electric leakage. At the same time, different voltages can be applied to the disks through the wires, so that the electric field distribution of each disk spinning point can be evenly distributed, which can reduce electrostatic repulsion and uniform fiber fineness; There are bases 140 at intervals of 5 mm to 100 mm on the shaft, which can fix the discs and be connected with the wires, and can be used to adjust the spacing of the discs according to actual production needs.

The spinning disc 80 adopts a hollow design, and its shape can be changed. The shape parameters include the degree of inclination, diameter, direction, quantity, etc. of the edge of the disc. Four symmetrically distributed screws are used to fix the spinning disc 80 and the base 140 (see accompanying drawing 2); The degree of inclination it has makes the disk have a certain liquid storage capacity. When rotating at a low speed, due to the existence of the inclined surface of the disk 80, continuous spinning can be realized; the diameter of each disk can be adjusted between 100 mm and 200 mm according to the distribution law of the electric field. According to the principle of electric field distribution, the diameter of the disc located in the middle of the rotating shaft 85 is larger than that on both sides. Such a disc diameter distribution can control the uniformity of the electric field between the spinning positions of each disc, and play the role of uniform spinning jet The arrangement of the disks can be that a single disk is arranged in parallel in one direction along the rotating shaft and evenly arranged, or it can be configured in pairs with the bottom faces facing each other (see accompanying drawing 3) and evenly arranged along the rotating shaft. The arrangement of the discs depends on the viscosity of the spinning solution; the number and spacing of the spinning discs vary according to the product width and gram weight requirements.

Described shielding case 75 adopts polytetrafluoroethylene inner wall, adopts circular arc design (referring to accompanying drawing 1), is designed with height control device 70 between shielding case and solution pool, can control the circular spinning position height by controlling the disc. The amount of liquid on the discs makes the thickness of the solution at the spinning position of each spinning disc uniform (generally control the thickness of the liquid to be 0.1mm to 0.5mm), so that the fineness of the spun fibers is uniform and the thickness of the electrospun film is uniform; shielding The cover 75 can keep the electrospinning core components in a relatively shielded state at the same time, which can save power, uniform jet flow, and concentrate high voltage on the top spinning position of the disk.

The positive and negative poles of the high-voltage power supply 10 are respectively connected to the pressure plate 130 on the high-performance plastic shaft and the target electrode plate 40, and the voltage value is 15kV-50kV.

The mesh delivery curtain 15 is made of relatively sparse and thin plastic, which has very little interference to the electric field, and is driven by rollers to drive the base fabric forward at a speed of 1-100m/min.

The grounded target electrode plate 40 can be traversed by known technology to make the fiber deposition more uniform; the target electrode plate 40 is connected to the negative pole of the high voltage power supply, and can play the role of enhancing the electric field; it can also be adjusted according to the needs of fiber collection, and the shape Variable, static and movable, so as to obtain electrospun nanofiber nonwoven fabrics that meet different needs.

The air suction device 35 is installed above the net delivery curtain and the target pole plate 40, and adopts a tapered design for uniform air suction, so that the spun fibers can be deposited evenly.

The design of the anti-slip device 50 is to install two motors respectively at the inlet end and the output end of the net transport curtain, and the two motors are installed on opposite sides with the same direction of rotation, so that the base cloth and the net transport curtain will not move with the rollers. slippage due to rotation.

The width of the disc-type electrospinning device is adjustable, generally between 300 mm and 2000 mm. In order to achieve large-scale and industrialized nanofiber production, especially hybrid electrospinning, the spinning units can be staggered (see Figure 4), so that the distribution of the collected fibers on the base cloth/receiver is more uniform, and at the same time the equipment The overall width and weight are further increased.

Instructions attached

Fig. 1 is a schematic diagram of the overall structure of an embodiment of the disc-type needle-free electrospinning device.

Fig. 2 is a cross-sectional view of a spinning core component of the disc-type needle-free electrospinning device.

Fig. 3 is a cross-sectional view of a disc-type needle-free electrospinning device using a bidirectional disc as a spinning core component.

Fig. 4 is a schematic diagram of a staggered arrangement of the disk-type needle-free electrospinning device.

Fig. 5 is a SEM picture of a nanofiber product of an embodiment of the centrifugal needle-free electrospinning device of the present invention.

Detailed ways

Further describe the present invention below in conjunction with embodiment and accompanying drawing thereof:

The disk-type needle-free electrospinning device designed by the present invention (referred to as the device, see Figures 1-4), the device mainly includes a liquid supply system, a spinning system, a power supply system, a receiving system, a transmission system and a control system.

The power supply system, receiving system, transmission system and control system adopt known technologies, which will not be repeated here.

Described spinning system (referring to accompanying drawing 1 and 2): comprise solution pond 55, and solution pond is a double-layer structure, and its high-performance plastic inner wall 110 has the effect of preventing electric leakage and saving electric energy, and adopts semicircular arc shape bottom groove, bottom The distance between the groove and the spinning disc 80 is 10 mm to 30 mm, which can save and even the solution; the solution pool 55 is connected with the high-performance plastic rotating shaft 85 by bearings, and the rotating shaft 85 is made of high-performance plastic. The wire 95 connected to the silk disk 80 is provided with a base 140 for installing the disk, and the wire 95 is connected to the corresponding pressure disk 130, which can realize the respective pressurization of each spinning disk 80; The disc 80 is installed on the base 140, and has a design with an inclination angle of 0°-90°, has a certain liquid storage capacity, is adjustable in diameter, can be pressurized separately, and can adopt different shapes according to actual needs; the solution A shielding cover 70 made of high-performance plastic is installed above the pool. The shielding cover adopts a smooth opening design and is arc-shaped. Its diameter is slightly larger than that of the spinning disc 80. The liquid-carrying thickness of the spinning position of the disk 80 has the functions of saving electric energy, reducing electric field mutual interference and uniform fiber fineness; a receiving device is installed above the spinning jet, including a mesh delivery curtain 15, and a reciprocating and traversing target electrode plate 40. Base cloth 20; the mesh transmission curtain 15 is made of light and thin plastic mesh with low mesh number, which has very little interference to the electric field; the target electrode plate 40 can move back and forth, and is connected with the negative pole of the high voltage power supply 10, and Different shapes can be used to make the fiber distribution more uniform and meet the needs of different products.

The solution pool 55 has a double-layer structure, adopts an arc-shaped design, and has an injection pump 120 and a return pump 125 . Solution pool inner wall 110 adopts high-performance plastics to make, and thickness is 5mm～20mm, has the effect of preventing electric leakage and saving electric energy; 30mm), which has the effect of saving raw materials and uniform solution; according to the output of the equipment, the difference between the injection pump 120 and the return pump 125 can be controlled, and the difference is generally set between 20g/h and 2000g/h, so that Precisely control the solution content in the solution pool and make the solution flow with it to prevent deposition.

The high-performance plastic rotating shaft 85 adopts high-performance plastic as the central shaft, and a wire 95 is laid inside, and the outer layer is covered with a high-performance plastic sleeve 91 , and the wire is connected with the base 140 and the pressure plate 130 . The rotating shaft 85 uses high-performance plastics as the central shaft, which has the functions of saving electric energy, preventing electric leakage and reducing electric field interference; the rotating shaft is provided with a base 140 connected to the wire 95 and installed for the spinning disc 80, between the bases The distance between them is 0.5cm, and the spinning discs 80 can be installed adjacently or at intervals as required; the wire 95 is connected with the base 140 and the pressure disc 130, and different voltages can be applied to each disc according to the distribution of the simulated electric field. Thereby it plays the role of uniform electric field; the effective spinning length of the rotating shaft is 30cm to 80cm; the rotating speed of the rotating shaft is 2r/min to 20r/min.

The spinning disk 80 adopts a hollow design, and its shape is controllable. It has an adjustable shape including the degree of inclination, diameter, direction, quantity, etc. of the disk, and has a smooth slope design. Four symmetrically distributed screws are used to fix the spinning disc 80 and the base 140 (see Figure 2); Excellent liquid storage capacity, when the disk rotates at low speed, continuous spinning can be realized due to the existence of the inclined surface of the disk; the diameter of each disk can be adjusted according to the law of electric field distribution, and the diameter of the disk is between 100mm and 200mm. The principle of electric field distribution, the diameter of the disc located in the middle of the rotating shaft is larger than that on both sides, such a disc diameter distribution can control the uniformity of the electric field between the spinning points of each disc, and play the role of uniform spinning jet; The direction can be unidirectional or bidirectional staggered (as shown in Figure 3), and can be adjusted according to the needs of the solution; the number of spinning discs can be changed according to the needs of product width and grammage.

The shielding cover 75 is made of high-performance plastic, and adopts an arc-shaped design with a smooth spinning point opening design, and its height is adjustable, as shown in Figure 1. The shielding cover made of high-performance plastic can play the role of shielding the electric field interference between equipment and stabilizing the jet flow, with a thickness of 10mm-15mm; the diameter of the shielding cover 75 is slightly larger than that of the spinning disc, and the opening width is between 30mm-50mm; The height control device 70 between the shielding cover and the solution pool is adjustable in height, and can control the amount of liquid carried at the spinning point of the disk, and the thickness of the solution at the spinning point of each spinning disk is evenly controlled. Generally, the thickness of the liquid carried is controlled to be 0.1mm. ~0.5mm, so that the fineness of the spun fibers is uniform; at the same time, the shielding cover can keep the core components of the electrospinning in a relatively shielded state, which can save power, stabilize the jet, and concentrate the high-pressure point on the top spinning point of the disc .

The receiving device is located above the spinning disk 80 and is composed of a base cloth 20 , a mesh curtain 15 , a target receiving plate 40 and an air suction device 35 . The base fabric 20 is driven by the net transmission curtain 15 at a speed of 1m/min to 100m/min; the net transmission curtain 15 is made of light and thin plastic net with a low mesh number, which has minimal interference to the electric field and is equipped with an anti-slip device 50 , the speed is 1m/min to 100m/min; the target electrode plate 40 is connected to the negative pole of the high-voltage power supply, and has a reciprocating traverse device, which can adopt various shapes, enhance the electric field, make the fiber distribution more uniform, and obtain a certain orientation. The function of the fiber net; the air suction device 35 is installed above the net delivery curtain and the target plate, and adopts a tapered design, with uniform air suction, so that the spun fibers can be evenly deposited.

Example 1

As shown in accompanying drawing 1, a kind of disc-type needleless large-scale electrospinning nanofiber non-woven fabric production equipment mainly includes: solution pool 55, polytetrafluoroethylene rotating shaft 85, spinning disc 80, shielding Cover 75, high-voltage power supply 10, net transmission curtain 15, grounded target electrode plate 40, air suction device 35, transmission device 25, anti-slip device 50, etc. During work, the depth of the solution pool 55 is 130mm, the depth of the solution is set to 100mm, and the difference between the injection pump 120 and the return pump 125 is set to 172g/h; the diameter of the spinning disk 80 is 200mm, and the number of effective jobs is 20. Install a spinning disc with a distance of 10mm between the bases, and the voltage applied to each spinning disc is the same, all of which are +25kV; the height of the shielding cover 75 is controlled so that the thickness of the liquid on the disc is 0.2mm; the polytetrafluoroethylene The rotational speed of the ethylene rotating shaft 85 is 15r/min, and the effective working width is 200mm; the target electrode plate 40 is pressurized at -25kV, and the reciprocating speed is 30 times/min; the transmission speed of the mesh curtain 15 and the base cloth 20 is 2m/min, and The negative pressure of the wind device is set to -10MPa; the distance between the spinning point of the spinning disk 80 and the base cloth 20 is set to 150mm.

First weigh a certain mass of PBS polymer particles, prepare a solution with a mass fraction of 14%, weigh the mass of the solvent chloroform/isopropanol (8:2), and then pour the solute and solvent into the magnetic rotor in turn. Place the jar on a constant temperature magnetic stirrer with a magnetic rotor speed of 1000r/h at room temperature and stir for about 2 hours to completely dissolve the PBS particles until the solution becomes uniform and transparent.

Before spinning, the height of the shielding cover 75 is set, and the height difference between its opening and the spinning disc is 0.2 mm, and the distance between the spinning point of the spinning disc 80 and the base cloth is adjusted to 150 mm; Then inject the PBS solution into the solution pool 55 through the injection pump 120. After the liquid level reaches 100mm, turn on the backflow pump 125 and set the difference to 172g/h; The rotational speed of the vinyl fluoride rotating shaft 85 is 15r/min, the transmission speed of the base cloth is set to be 2m/min, and the reciprocating speed of the target electrode plate 40 is 30 times/min; after the inclined part of the spinning disc 80 is completely covered by the solution, open The high-voltage power supply 10 is set at 25kV to start spinning.

After 10 minutes, turn off the high-voltage power supply 10, the injection pump 120, the return pump 125, the mesh transmission curtain transmission device 25, the air suction device 35, the target electrode plate reciprocating transmission device, and the rotating shaft transmission device in sequence. The PBS/melt-blown nonwoven composite fabric with uniform distribution of electrospun nanofibers was obtained, with an effective width of 200 mm, a grammage of electrospun nanofibers of 1 g/m ² , and a length of 20 m.

Example 2

As shown in accompanying drawing 1, a kind of disc-type needleless large-scale electrospinning nanofiber non-woven fabric production equipment mainly includes: solution pool 55, polytetrafluoroethylene rotating shaft 85, spinning disc 80, shielding Cover 75, high-voltage power supply 10, net transmission curtain 15, grounded target electrode plate 40, air suction device 35, transmission device 25, anti-slip device 50, etc. During work, the depth of the solution pool 55 is 13cm, the depth of the solution is set to 10cm, and the difference between the injection pump 120 and the return pump 125 is set to 750g/h; the diameter of the spinning disk 80 is 200mm, and the spinning disk adopts a bidirectional design ( See accompanying drawing 3), the number of effective work is 25, and a spinning disc is installed every 3 bases, and its spacing is 20mm, and the applied voltage of each spinning disc is the same, both are +30kV; the height of the shielding cover is 75 The control is that the thickness of the liquid on the disc is 0.15mm; the rotation speed of the PTFE shaft 85 is 20r/min, and the effective working width is 500mm; the target electrode plate 40 is pressurized at -30kV, and the reciprocating speed is 30 times/min; The transmission speed of the curtain 15 and the base cloth 20 is 2m/min, the negative pressure of the air suction device is set to -10MPa; the distance between the spinning point of the spinning disk 80 and the base cloth 20 is set to 200mm.

First weigh a certain mass of PVA high polymer particles, prepare a solution with a mass fraction of 16%, weigh the PVA high polymer particles and deionized water according to the percentage, and then pour the solute and solvent into the frosted wide mouth with a magnetic rotor. In the bottle, at room temperature, place the jar on a constant temperature magnetic stirrer with a magnetic rotor speed of 1000r/h and stir for about 2 hours to completely dissolve the PVA particles until the solution becomes uniform and transparent.

Before spinning, the height of the shielding cover 75 is set, and the height difference between its opening and the spinning disc is 0.15 mm, and then the distance between the spinning point of the spinning disc 80 and the base cloth is adjusted to 200 mm. Then inject the solution into the solution pool 55 through the injection pump 120. After the liquid level reaches 100mm, turn on the backflow pump 125 and set the difference to 750g/h; The rotating speed of ethylene rotating shaft 85 is 20r/min, and setting base cloth conveying speed is 2m/min, and target electrode plate 40 reciprocating speed is 30 times/min; , turn on the high-voltage power supply 10, set the voltage to 30kV, and start spinning.

After 10 minutes, turn off the high-voltage power supply 10, the injection pump 120, the return pump 125, the mesh transmission curtain transmission device 25, the air suction device 35, the target electrode plate reciprocating transmission device, and the rotating shaft transmission device in sequence. A PVA nonwoven fabric with uniform distribution of electrospun nanofibers was obtained, with an effective width of 500 mm, a grammage of electrospun nanofibers of 2 g/m ² , and a length of 20 m.

Claims (10)

1. a disc-type needle-free electrospinning device (referring to Fig. 1), comprising a solution pool, a high-performance plastic rotating shaft, a metal rotating disk, a shielding cover, a grounded metal pole plate, an air suction device, and an anti-slip device, characterized in that : The inner wall layer of the solution pool is made of high-performance plastic, which has the functions of safe insulation, saving electric energy, preventing electric leakage and reducing electric field interference; the solution pool of the rotating shaft adopts an arc-shaped design, and the inner diameter is slightly larger than the diameter of the spinning disc. It has the function of saving raw materials and uniform solution; according to the output of the equipment, the difference between the return pump and the return pump can be controlled, and the solution content in the solution pool can be precisely controlled, and the solution can flow with it to prevent polymer deposition. the 2. The disc-type needle-free electrospinning device according to claim 1, characterized in that: the inside of the high-performance plastic shaft is laid with wires, the outer layer is covered with a high-performance plastic sleeve, and the wires and the base and The pressure plate is connected; the high-performance plastics include polytetrafluoroethylene, polyphenylene sulfide or polypropylene plastics. the 3. The disc-type needle-free electrospinning device according to claim 1, characterized in that: the high-performance plastic rotating shaft is provided with a base that is connected to the wire and is used to install the spinning disc; the wire and the base and The pressure discs are connected, and different voltages can be applied to each disc according to the requirements of the electric field distribution, so as to play the role of a uniform electric field. the 4. The disc-type needle-free electrospinning device according to claim 1, characterized in that: the spinning disc 80 adopts a hollow design, and its shape is adjustable, including the degree of inclination, diameter, direction, and quantity of the disc etc., the outer edge of the disc has a sleek sloping design. the 5. The disk-type needle-free electrospinning device according to claim 1, characterized in that: the inclination of the disk is between 0° and 90°, and the inclination design of the disk itself makes the disk have a certain storage capacity. Liquid capacity, when the disc rotates at low speed, continuous spinning can be realized due to the existence of the degree of inclination of the disc. the 6. The disc-type needle-free electrospinning device according to claim 1, characterized in that: according to the principle of electric field distribution, the diameter of the disc located in the middle of the rotating shaft is larger than that on both sides, and such a disc diameter distribution can control the diameter of each circle. The uniformity of the electric field between the spinning positions of the discs, and it acts as a uniform spinning jet. the 7. The disc-type needle-free electrospinning device according to claim 1, characterized in that: the discs can be placed parallel to the same direction along the rotating shaft, or a pair of discs can be formed with the bottom faces facing each other, and then evenly distributed along the rotating shaft The placement can be adjusted according to the requirements of electrospinning; the number of spinning discs can be adjusted according to the requirements of the product width. the 8. The disc-type needle-free electrospinning device according to claim 1, characterized in that: the shielding cover is made of polytetrafluoroethylene, adopts an arc-shaped design, and has a smooth spinning position opening design, Height adjustable. The shield made of polytetrafluoroethylene can shield the electric field interference between equipment and stabilize the jet flow; the diameter of the shield is slightly larger than that of the spinning disc, and the height control device between the shield and the solution pool is adjustable in height. It can control the amount of liquid in the spinning position of the disc, and evenly the thickness of the solution in each spinning point of the spinning disc. Generally, the thickness of the liquid is controlled to be 0.1mm~0.5mm, so that the fineness of the spun fibers is uniform; the shielding cover can also be used at the same time Make the electrospinning core components in a relatively shielded state, which can save electric energy, stabilize the jet flow, and concentrate the high voltage point on the top spinning position of the disc. the 9 . The disc-type needle-free electrospinning device according to claim 1 , wherein the disc can also be a plane disc with no inclination at the edge, and the thickness is 0.5-100 mm. the 10. The disk-type needle-free electrospinning device according to claim 1, characterized in that: the diameter of each disk can be adjusted according to the electric field distribution law, and the diameter of the disk is between 50 mm and 200 mm. the

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