Electrospinning device with improved safety

Abstract

The present invention relates to a technology for preventing safety accidents due to discharge and overheating in an electrospinning device and improving the quality and efficiency of fiber spinning An abnormal state is detected in real time through a discharge detection sensor and a temperature sensor, and the supply of high voltage is blocked to minimize the risk of fire. A flame-retardant coating layer is applied to a mixer unit and a nozzle pack unit, and an air supply unit supports stabilization of the fiber shape and removal of the volatile solvent. Through this configuration, work safety is increased, and the reliability and performance of the device are maximized.

Description

Electrospinning device with improved safety

[0001] The present invention relates to a technology for improving the safety of an electrospinning device, and in particular to an electrospinning device including various safety devices and structures to prevent safety accidents caused by discharge and overheating and to reduce the risk of fire in a device that uses high voltage to spin a fiber raw material solution.

[0002] Electrospinning is a technology that uses a high-voltage electric field to spin polymeric materials from a solution into microfibers, and it is utilized in various industrial fields such as nanofiber manufacturing, filters, tissue engineering, and medical textiles. Such electrospinning devices produce fibers through the processes of charging using high voltage, supplying the solution, forming the fibers, and collecting them.

[0003]

[0004] An electrospinning device generally includes the following components. The high-voltage power supply generates a high voltage of tens of kV or more to impart an electric charge to the fiber raw material solution, and the solution supply serves to deliver the fiber raw material solution to the nozzle pack. The nozzle pack then discharges the fiber raw material solution in the form of fine fibers.

[0005] Korean Registered Patent Publication No. 10-1400280 describes an invention relating to an electrospinning device, detailing the background of the electrospinning device.

[0006]

[0007] However, existing electrospinning devices have several safety issues due to the nature of handling high voltage.

[0008] First, if the distance between the high-voltage electrode and ground is inappropriate, or if impurities accumulate on the electrode surface, the electric field becomes unbalanced, which can lead to discharge (sparks or arcs). Discharge is accompanied by high temperatures and intense light, which can ignite surrounding volatile substances and potentially lead to a fire. Existing devices lack systems to detect or control discharges in real time, making it difficult to prevent safety accidents.

[0009] In addition, since electrospinning devices continuously use high voltage, there is a high possibility that components such as the nozzle pack and mixer sections will overheat. In particular, overheated components come into contact with volatile solvent vapors, increasing the risk of fire. Existing devices currently lack real-time monitoring systems to detect or control overheating.

[0010] In addition, fiber raw material solutions used in the electrospinning process often contain volatile organic solvents (e.g., acetone, toluene, etc.), which can easily ignite due to discharge or overheating. Existing devices lack structural improvements or safety devices to address these fire risks, which can compromise the safety of the working environment.

[0011] Furthermore, conventional electrospinning devices lack the capability to detect or analyze discharge occurrences and control them appropriately. If a discharge occurs, the device continues to operate, increasing the likelihood of fire or equipment damage.

[0012] In addition, there is a lack of technology to monitor the temperature of the nozzle pack or mixer part in real time in the electrospinning device and to identify and control abnormal conditions. As a result, the lifespan of the device is shortened due to overheating, and the risk of fire increases.

[0013] [Prior Art Literature]

[0014] [Patent Literature]

[0015] Republic of Korea Registered Patent Publication No. 10-1400280

[0016] The main objective of the present invention is to prevent safety accidents and fire hazards caused by discharge and overheating that may occur in an electrospinning device. To this end, abnormal conditions are detected in real time through a discharge detection sensor and a temperature sensor, and the safety of the device is ensured by cutting off the high-voltage supply. In addition, the invention aims to minimize fire hazards through a flame-retardant coating layer and an air supply unit, while simultaneously improving the quality and efficiency of fiber spinning.

[0017] To achieve the objective of the present invention, the electrospinning device with improved safety according to the present invention comprises: a solution supply unit that supplies a solution in which a fiber raw material is dissolved; a high-voltage supply unit that imparts an electric charge to the solution; a nozzle pack unit that discharges the solution to which the electric charge has been imparted; and a discharge detection sensor coupled to the nozzle pack unit to measure a discharge pattern.

[0018] In addition, the discharge detection sensor of the electrospinning device with improved safety according to the present invention is linked with a control unit, and the detected discharge pattern is compared with a preset normal discharge pattern.

[0019] In addition, the discharge detection sensor of the electrospinning device with improved safety according to the present invention includes an electric sensor, an optical sensor, and an acoustic sensor.

[0020] In addition, the control unit of the electrospinning device with improved safety according to the present invention includes a data collection unit that converts data collected through the discharge shock sensor into a digital signal and stores it.

[0021] In addition, the control unit of the electrospinning device with improved safety according to the present invention includes a signal processing unit that derives a discharge pattern by processing a signal collected through the data collection unit using FFT and time-frequency analysis.

[0022] In addition, the control unit of the electrospinning device with improved safety according to the present invention includes an analysis unit that identifies abnormal discharge by comparing a preset normal discharge pattern with a derived discharge pattern.

[0023] In addition, the control unit of the electrospinning device with improved safety according to the present invention includes a control unit that controls a relay unit linked to the high-voltage supply unit to cut off the power supply of the high-voltage supply unit when an abnormal discharge is detected.

[0024] The present invention provides the following effects.

[0025] First, safety is enhanced. Abnormal discharge is quickly detected through the discharge detection sensor (1100) and the control unit (1000), and the high-voltage supply unit (100) is cut off to prevent fire and device damage. In addition, safety is maximized by combining the first temperature sensor (910) and the second temperature sensor (920) with the mixer unit (300) and the nozzle pack unit (600) to detect and respond to overheating conditions in real time.

[0026] Next, the quality of electrospinning is improved. By optimizing the structure of the mixer unit (300) and the nozzle pack unit (600) and the electrode (320), the charge of the fiber raw material solution is maintained uniformly to improve spinning quality, and the air flow is controlled through the air supply unit (500) to stabilize the trajectory and shape of the spun fiber and maintain uniformity of diameter and quality.

[0027] Next is efficient fiber collection. The collector unit (800) utilizes a roller (810) and a belt (820) to continuously collect and move fibers, and applies a negative voltage to enable uniform distribution and efficient collection of fibers.

[0028] Next, the working environment and safety are improved. Volatile solvents are removed through the drying section (700) and the spun fibers are stably solidified to improve fiber quality and enhance safety in the working environment, and a flame-retardant coating layer is applied to the mixer section (300) and the nozzle pack section (600) to minimize the risk of fire caused by discharge or overheating.

[0029] Next is automation and reliability enhancement. Through a control unit (1000) including a data collection unit (1200), a signal processing unit (1300), and an analysis unit (1400), discharge and temperature data are recorded and analyzed in real time to support the maintenance and performance optimization of the device.

[0030] Finally, there is energy efficiency and environmental protection. Energy consumption is minimized through PID control and high-efficiency design, while the environmental impact of the working environment is reduced through the proper removal of solvent vapors and air circulation devices.

[0031] FIG. 1 is an enlarged view of a hinge system according to the present invention.

[0032] FIG. 2 is a block diagram of the main components of an electrospinning device according to the present invention.

[0033] FIG. 3 is a block diagram illustrating the configuration of a control unit according to the present invention.

[0034] FIG. 4 illustrates an example in which a plurality of mixer parts and a plurality of nozzles are formed according to the present invention.

[0035] Figure 5 is an SEM image of a nanofiber produced using an electrospinning device according to the present invention.

[0036] The present invention relates to an electrospinning device with improved safety, comprising: a solution supply unit for supplying a solution in which a fiber raw material is dissolved; a high-voltage supply unit for imparting an electric charge to the solution; a nozzle pack unit for discharging the solution to which the electric charge has been imparted; and a discharge detection sensor coupled to the nozzle pack unit for measuring a discharge pattern.

[0037] The present invention will be described in detail below with reference to the drawings. The embodiments described below are provided as examples to ensure that the concept of the present invention is sufficiently conveyed to a person skilled in the art. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. Furthermore, in the drawings, the size and thickness of the device, etc., may be exaggerated for convenience. Throughout the specification, the same reference numerals indicate the same components.

[0038]

[0039] FIG. 1 illustrates the configuration of an electrospinning device according to the present invention. FIG. 2 illustrates a block diagram of the main components of an electrospinning device according to the present invention. Hereinafter, the configuration and effects of an electrospinning device according to the present invention will be explained with reference to FIG. 1 and FIG. 2.

[0040] The electrospinning device according to the present invention includes a high voltage supply unit (100), a solution supply unit (200), a mixer unit (300), an air supply unit (500), a nozzle pack unit (600), a drying unit (700), and a collector unit (800).

[0041] The high-voltage supply unit (100) includes a high-voltage generator (110) and a high-voltage distributor (120). The high-voltage generator is an essential component of the electrospinning device and generates high voltage to impart an electric charge to the fiber raw material solution. The high-voltage generator (110) is a device that converts an input voltage (AC or DC) into a high voltage of tens of kV by high-frequency conversion and transformer-based step-up. Internally, it includes a high-voltage transformer, a rectifier, and a filter circuit to ensure a stable high-voltage output.

[0042] The high-voltage distributor (120) serves to distribute the voltage generated from the high-voltage generator (110) to the mixer section (300) within the electrospinning device.

[0043]

[0044] The solution supply unit (200) includes a tank (210), a pump (220), and a solution distributor (230). A solution in which a fiber raw material is dissolved is stored in the tank (210), and the solution is transferred to the solution distributor (230) via the pump (220). The solution distributor (230) is connected to the mixer unit (300) and serves to distribute the solution to the mixer unit (300). The amount of distribution can be adjusted, and since this is a known function of a distributor, a detailed description will be omitted.

[0045]

[0046] The mixer unit (300) consists of a main body (310) and an electrode (320). The main body (310) is in the shape of a tube, through which a solution in which fiber raw material is dissolved from a solution distributor (230) passes. The main body (310) is designed in a cylindrical or tube shape to stably maintain the flow of the solution passing through its interior. A flow path design (e.g., straight flow type, vortex suppression type) may be applied to the interior of the main body (310) to optimize the flow of the solution. The main body (310) maintains the fiber raw material solution supplied from the solution distributor (230) uniformly and transmits the charged solution through the electrode (320) to the nozzle pack unit (600).

[0047]

[0048] The electrode (320) is installed inside or outside the main body (310) and is electrically connected to the high-voltage distributor (120). The shape of the electrode (320) can be designed as a rod, ring, or mesh type to optimize the application of charge to the solution. The high voltage received from the high-voltage distributor (120) is applied to the solution to make it charge.

[0049]

[0050] The mixer unit (300) may additionally perform a mixing function to maintain the uniformity of the concentration, viscosity, or charge state of the fiber raw material solution. It may be designed so that the solution is naturally mixed by installing a spiral channel or a porous obstacle inside the main body, or the solution may be mechanically mixed by installing a rotary blade or screw inside the main body. In addition,

[0051] An ultrasonic generator can be used to support fine mixing and degassing (bubble removal) of the solution.

[0052]

[0053] Additionally, the mixer section (300) may have a flame-retardant coating layer formed thereon to ensure safety in a high-voltage environment. To reduce the risk of fire, the exterior and interior surfaces of the main body (310) may be treated with a flame-retardant coating.

[0054]

[0055] Specifically, the coating layer is coated with a flame-retardant coating composition, and the flame-retardant coating composition may include a solvent, a flame retardant, a silane coupling agent, an epoxy compound, and an acid anhydride.

[0056] The above solvent is intended to control the concentration of the composition and induce a reaction between the active ingredients included in the composition, and may use anhydrous or hydrated lower alcohols having 1 to 4 carbon atoms (methanol, ethanol, ethanol, propanol, butanol, etc.), toluene, phenol, and mixed solvents of the above alcohols and water, but is not limited thereto.

[0057] The above flame retardant is included as an active ingredient in a coating composition to directly provide a flame-retardant effect and may include a flame retardant selected from the group consisting of phosphorus-based flame retardants such as trimethyl phosphate, triethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixyllenyl phosphate, resorcinol bis(diphenyl phosphate), phenyl diresorcinol phosphate, bisphenol diphenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, phenyl di(isopropylphenyl) phosphate, triisophenyl phosphate, diphenyl phosphate, and resorcinol diphosphate; metal hydroxide-based flame retardants such as aluminum hydroxide and magnesium hydroxide; nitrogen-containing compound-based flame retardants; graphite material-based flame retardants; melamine cyanurate-based flame retardants; metal oxide-based flame retardants such as antimony oxide; phosphate-based flame retardants and mixtures thereof.

[0058] The above silane coupling agent is included to improve the adhesion between the coating composition and the surface of the substrate to which the coating composition is attached, and to improve the efficiency of the flame-retardant coating to enhance flame retardancy, flame resistance, etc., and may include an organic functional group capable of bonding with an organic compound and a hydrolyzing group capable of reacting with an inorganic material.

[0059] The above silane coupling agent may include a silane coupling agent selected from the group consisting of an alkyl group-containing silane coupling agent, a phenyl group-containing silane coupling agent, an amino group-containing silane coupling agent, an epoxy group-containing silane coupling agent, an acrylate group-containing silane coupling agent, an isocyanate group-containing silane coupling agent, a fluorine group-containing silane coupling agent, a vinyl group-containing silane coupling agent, and mixtures thereof.

[0060] More specifically, the alkyl group-containing silane coupling agent may be methyltrimethoxysilane, dimethyldimethoxysilane, octyltriethoxysilane, etc., the alkyl group-containing silane coupling agent may be dimethoxydiphenylsilane, phenyltrimethoxysilane, etc., the phenyl group-containing silane coupling agent may be used, and the amino group-containing silane coupling agent may be 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-aminoethyl-3-aminopropylmethyldimethoxysilane, N-2-aminoethyl-3-aminopropyltrimethoxysilane, N-2-aminoethyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-ethyl-2-aminoethyltrimethoxysilane, N-ethyl-2-aminoethylmethyldimethoxysilane, N-ethyl-3-aminopropyltrimethoxysilane, N-ethyl-3-aminopropylmethyldimethoxysilane, etc. There are. Meanwhile, epoxy group-containing silane coupling agents include 2-glycidoxyethylmethyldimethoxysilane, 2-glycidoxyethylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethylmethyldiethoxysilane, 3-(3,4-epoxycyclohexyl)propylmethyldimethoxysilane, 3-(3,4-epoxycyclohexyl)propylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-(3,4-epoxycyclohexyl)propyltrimethoxysilane, 3-(3,4-epoxycyclohexyl)propyltriethoxysilane, etc. may be used, and as acrylate group-containing silane coupling agents, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxymethyltriethoxysilane, etc. may be used.Meanwhile, the above-mentioned fluorine group-containing silane coupling agent may be heptadecafluoro-1,1,2,2-tetradecyltrimethoxysilane, trifluoropropyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, heptadecafluorodecyltriisopropoxysilane, etc.

[0061] The above epoxy compound is intended to improve the mechanical strength of the coating layer by providing high adhesion and durability, and to enhance the flame retardant effect by strengthening resistance to heat and chemicals, and may include bisphenol diglycidyl ether oligomers, triglycidyl ether compounds, or mixtures thereof.

[0062] The above bisphenol diglycidyl ether oligomer may be selected from the group consisting of bisphenol A diglycidyl ether oligomer having a weight-average molecular weight of 300 to 1,000 g / mol, bisphenol F diglycidyl ether oligomer having a weight-average molecular weight of 300 to 1,000 g / mol, bisphenol AF diglycidyl ether oligomer having a weight-average molecular weight of 300 to 1,000 g / mol, and mixtures thereof.

[0063] The above triglycidyl ether compound may be selected from the group consisting of trimethylolpropane triglycidyl ether, triphenylolmethane triglycidyl ether, trimethylolethane triglycidyl ether, and mixtures thereof.

[0064] Specifically, it is preferable to use a bisphenol A diglycidyl ether oligomer with a weight-average molecular weight of 300 to 1,000 g / mol and a bisphenol F diglycidyl ether oligomer with a weight-average molecular weight of 300 to 1,000 g / mol as the epoxy compound, and more specifically, it is preferable that the weight ratio of the bisphenol A diglycidyl ether oligomer and the bisphenol F diglycidyl ether oligomer is 1:0.5 to 1:3, and within the above weight ratio range, the flame retardancy and adhesion of the coating composition can be maximized.

[0065] The above acid anhydride is included for the curing of the epoxy compound, and by inducing the curing action of the epoxy compound, it can not only improve the adhesion and durability of the coating composition to the substrate surface, but also ultimately improve the flame retardant performance of the coating composition. Specifically, the above acid anhydride may include an acid anhydride selected from the group consisting of tetrahydrophthalic anhydride (THPA), methylhexahydrophthalic anhydride (Me-HHPA), 3-methyl-1,2,3,6-tetrahydrophthalic anhydride, trimethylic anhydride (TMA), phthalic anhydride (PA), benzophenone tetracarboxylic anhydride (BTDA), and mixtures thereof.

[0066] Preferably, the flame-retardant coating composition may comprise 30 to 50 parts by weight of a flame retardant, 20 to 40 parts by weight of a silane coupling agent, 20 to 40 parts by weight of an epoxy compound, and 20 to 40 parts by weight of an acid anhydride, based on 100 parts by weight of a solvent. According to the above weight range, not only can the flame-retardant effect intended by the present invention be maximized, but the durability of the coating layer can also be maximized by further improving adhesion to the substrate surface. However, if the weight is less than or exceeds the above weight range, the flame-retardant effect and / or adhesion to the substrate surface may be reduced.

[0067] Preferably, the flame-retardant coating composition may further include additional additives capable of exhibiting a flame-retardant effect, and more specifically, may further include a compound represented by the following Chemical Formula 1 and a compound represented by the following Chemical Formula 2:

[0068] [Chemical Formula 1]

[0069]

[0070] [Chemical Formula 2]

[0071]

[0072] Here,

[0073] m is an integer from 1 to 4, and

[0074] n is an integer from 1 to 5, and

[0075] R1 and R2 are identical or different from each other and are each independently selected from the group consisting of hydrogen, a halogen group, a cyano group, a hydroxyl group, a nitro group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, and a substituted or unsubstituted alkynyl group having 2 to 24 carbon atoms.

[0076] When R1 and R2 are substituted, they are substituted with a substituent selected from the group consisting of hydrogen, a nitro group, a halogen group, a hydroxyl group, a carboxyl group, an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, and an alkynyl group having 2 to 24 carbon atoms, and when they are substituted with multiple substituents, they are the same or different from each other.

[0077] More preferably, the compound represented by Chemical Formula 1 is a compound represented by Chemical Formula 3 below, and the compound represented by Chemical Formula 2 may be a compound represented by Chemical Formula 4 below:

[0078] [Chemical Formula 3]

[0079]

[0080] [Chemical Formula 4]

[0081]

[0082] When the flame-retardant coating composition further includes the compound represented by Chemical Formula 1 and the compound represented by Chemical Formula 2, due to the specific functional groups and structural characteristics of each compound, the flame-retardant effect can be further enhanced through a synergistic effect upon mixing with other active ingredients, and excellent adhesion to the substrate can be exhibited.

[0083] More specifically, the above compounds are fluorine-containing fluorine-based compounds that provide high thermal stability, allowing them to maintain their structure without deformation even at high temperatures, thereby maximizing flame-retardant performance. Additionally, they exhibit excellent resistance to chemicals, enabling them to be mixed with flame-retardant materials to provide even more effective flame-retardant properties. Furthermore, the compounds, by containing fluorine, can suppress reactions with oxygen during combustion and can further enhance flame-retardant properties by cutting off the oxygen supply in the event of a fire.

[0084] Specifically, the additional additive may comprise 10 to 20 parts by weight of a compound represented by Formula 1 and 10 to 20 parts by weight of a compound represented by Formula 2, based on 100 parts by weight of a solvent. More specifically, the flame-retardant coating composition of the present invention may comprise 30 to 50 parts by weight of a flame retardant, 20 to 40 parts by weight of a silane coupling agent, 20 to 40 parts by weight of an epoxy compound, 20 to 40 parts by weight of an acid anhydride, 10 to 20 parts by weight of a compound represented by Formula 1, and 10 to 20 parts by weight of a compound represented by Formula 2, based on 100 parts by weight of a solvent. When following the above weight range, the flame-retardant effect can be further maximized due to the synergistic effect resulting from the mixing of each component, as well as the adhesion of the coating layer to the substrate can be maximized. However, if the weight is below the above weight range or exceeds the above weight range, the effect may be reduced.

[0085]

[0086] Preparation Example

[0087] Preparation of flame-retardant coating composition

[0088] The flame-retardant coating composition was prepared by mixing triphenyl phosphate, a flame retardant; 3-glycidoxypropyltrimethoxysilane, a silane coupling agent; an epoxy compound in which bisphenol A diglycidyl ether oligomer with a weight-average molecular weight of 1,000 g / mol and bisphenol F diglycidyl ether oligomer with a weight-average molecular weight of 1,000 g / mol were mixed in a weight ratio of 1:1; tetrahydrophthalic acid anhydride, an acid anhydride; a compound represented by Chemical Formula 3 and a compound represented by Chemical Formula 4 in the weight ranges shown in Table 1 below; maintaining the temperature at 75°C to 90°C and stirring at 2,500 to 3,000 rpm for 2 to 2.5 hours.

[0089] Meanwhile, the above compounds were purchased from Tokyo Chemical Industry Co., Ltd. and used:

[0090] [Chemical Formula 3]

[0091]

[0092] [Chemical Formula 4]

[0093]

[0094] BY1BY2BY3BY4BY5BY6 Solvent 100100100100100100 Flame Retardant 402530405055 Silane Coupling Agent 301520304045 Epoxy Compound 301520304045 Acid Anhydride 301520304045 Compound represented by Chemical Formula 3-7.510152025 Compound represented by Chemical Formula 4-7.510152025

[0095] (Unit: parts by weight)

[0096]

[0097] Experimental Example

[0098] Adhesion test of flame-retardant coating layer

[0099] A coating layer was prepared by applying the coating composition of the above manufacturing example to an aluminum steel plate test specimen and heat-curing it. Subsequently, the adhesion of the coating layer was measured according to KS D 6711 (Coated plates and plates for aluminum and aluminum alloys), and the degree of adhesion was evaluated as an index by setting the case where the coating surface was completely peeled off as 0 and the case where the coating surface was not peeled off at all as 10. A higher number in the index indicates superior adhesion.

[0100] The results are as shown in Table 2 below.

[0101]

[0102] BY1BY2BY3BY4BY5BY6Adhesion57910107

[0103] (Unit: exponent)

[0104] According to Table 2 above, when a coating layer is formed using the flame-retardant coating composition of the present invention, excellent adhesion of the coating layer can be confirmed overall. Specifically, it was confirmed that adhesion is better when additional additives are included, and in particular, it was confirmed that the adhesion of the coating layer is best in the range of BY3 to BY5.

[0105]

[0106] Flame retardancy and flame resistance testing of the flame-retardant coating layer

[0107] The coating composition of the above manufacturing example was applied to the surface of wire cables of the same thickness and length and heat-cured to produce a coating layer. Subsequently, the flame retardancy and flame resistance of each cable specimen with the coating layer formed and the control specimen without the coating layer formed were measured according to KS K 0593, and the length of each burned specimen was checked, and the results are shown in Table 3 below.

[0108]

[0109] BY1BY2BY3BY4BY5BY6 Control Group Flame Retardant, Flame Retardant (mm) 69463331324498

[0110] According to Table 3 above, it was confirmed that when a coating layer is formed using the flame-retardant coating composition of the present invention, superior flame-retardant and flame-retardant effects can be exhibited compared to a control group without a coating layer. Furthermore, it was confirmed that the effect is even better when additional additives are included as active ingredients in the coating composition, and in particular, it was confirmed that flame-retardant and flame-retardant activity is maximized in the range of BY3 to BY5.

[0111]

[0112] Additionally, a first temperature sensor (910) may be coupled to the main body (310). Through the first temperature sensor (910), the safety of the electrospinning device according to the present invention can be increased.

[0113] The first temperature sensor (910) is linked with the control unit (1000). The control unit (1000) includes a data collection unit (1200), a signal processing unit (1300), an analysis unit (1400), a control unit (1500), and a warning unit (1600). The control unit (1000) is also linked with the discharge detection sensor (1100), as will be described later, and a block diagram of the control unit (1000) is shown in FIG. 3.

[0114] The first temperature sensor (910) is, for example, a fixed temperature sensor and is a sensor for continuously monitoring the temperature of a specific location. In addition, it may be a non-contact temperature sensor, such as an infrared (IR) temperature sensor.

[0115] The data collection unit (1200) is a high-speed data logging system and an A / D converter, and serves to convert analog data received from the first temperature sensor (910) into a digital signal.

[0116]

[0117] The signal processing unit (1300) removes noise and calculates the average temperature. A threshold value (e.g., 50°C) for determining an overheating state is preset, and the rate of temperature rise is detected through time-temperature graph analysis. For example, the rate of temperature change over time (rate of temperature rise) can be calculated.

[0118]

[0119] The analysis unit (1400) processes sensor data in real time to determine whether the temperature threshold is exceeded. Additionally, for example, the temperature patterns of normal and abnormal states can be compared with a pre-configured database. In the case of a normal pattern, the temperature changes within a certain range, while in the case of an abnormal pattern, the temperature exceeds the threshold or rises rapidly.

[0120]

[0121] When an abnormal temperature rise is detected, the control unit (1500) generates a warning signal through the warning unit (1600) or cuts off the power of the high-voltage supply unit (100).

[0122] The warning unit (16000) includes an LED display, a warning light, and a speaker, and provides a visual / audio warning notification when an overheating condition occurs. In addition, temperature data can be visualized as a graph to indicate the overheating section.

[0123]

[0124] Through the above configuration, the temperature of the device is continuously monitored to prevent potential overheating risks in advance, and even small temperature changes can be accurately detected by combining a temperature sensor and a signal processing module. In addition, safety can be enhanced by automatically shutting off the power when an overheating condition is detected, and device maintenance and performance optimization can be contributed by recording and analyzing temperature data.

[0125]

[0126] In the present invention, a second temperature sensor (920) is coupled to the nozzle pack (600) to detect the temperature of the nozzle pack (600) and to be linked with the control unit (1000). It is applied on the same principle as the first temperature sensor (910), and a detailed description is omitted to prevent redundancy.

[0127] As described above, the present invention has the advantage of maximizing safety by sensing the temperature in the parts where discharge may occur in both the mixer part (300) and the nozzle pack part (600) to detect an overheating state and controlling it to take countermeasures.

[0128]

[0129] The air supply unit (500) includes a compressor (510) and an air nozzle (520). The air nozzle (520) is directed toward the vicinity of the nozzle (620) of the nozzle pack unit (600) and sprays high-pressure air generated from the compressor (510). The air supply unit (500) performs an important function in controlling and stabilizing the airflow during the process of fiber formation through the nozzle pack unit (600). The extruded solution moves to the collector unit (800) by an electric field, and at this time, the air supply unit (500) controls the airflow to stabilize the trajectory and shape of the extruded fiber. In addition, the appropriate airflow maintains a uniform elongation speed of the fiber, thereby maintaining the diameter and quality of the extruded fiber at a constant level.

[0130] Additionally, the air supply unit (500) serves to remove vapors of volatile solvents. Fiber raw material solutions often contain volatile solvents such as acetone and ethanol. The air supply unit (500) inhales or expels solvent vapors generated around the nozzle to maintain a safe working environment.

[0131] In addition, it can prevent steam from accumulating inside the device, thereby increasing the safety of the radiation process and reducing the risk of fire.

[0132] Additionally, the air supply unit (500) absorbs or disperses heat generated during the radiation process, thereby lowering the temperature inside the device. In particular, it plays an important role in lowering the temperature around the nozzle pack unit (600).

[0133] In addition, appropriate cooling air is provided so that the spun fibers can solidify as they cool in the air.

[0134] Additionally, the air supply unit (500) induces the spun fibers to be oriented in a specific direction. By controlling the direction and speed of the airflow, it helps the fibers to be aligned in a desired shape on the collection surface.

[0135]

[0136] The nozzle pack unit (600) includes a nozzle pack body (610) and a nozzle (620). The nozzle pack unit (600) is a core component of the electrospinning device and enables stable and uniform spinning by working in conjunction with the high-voltage supply unit (100) and the solution supply unit (200).

[0137] The nozzle pack body (610) is designed to support and fix multiple nozzles and is made of a modular frame. For example, a distribution channel may be formed inside to maintain a uniform flow of the solution.

[0138] As described above, since there is a high probability of discharge near the nozzle pack portion (600), a flame-retardant coating layer may be formed on the outer surface of the nozzle pack body (610). As the composition and effect of the flame-retardant coating layer have been described above, a redundant description will be omitted.

[0139]

[0140] The nozzle (620) is generally made of stainless steel or a highly corrosion-resistant metal to maintain durability and precision. Multiple nozzles (620) may be formed. At this time, multiple mixer sections (300) and nozzles (620) may be formed, and the designer may pre-design and determine the number of nozzles (620) to optimize the distribution of the solution. FIG. 4 illustrates an example in which multiple mixer sections (300) and multiple nozzles (620) are formed.

[0141]

[0142] In addition, the nozzle (620) of the present invention is characterized by having a plurality of nozzles compared to a conventional electrospinning device. That is, it is characterized by including a plurality of nozzles (620) compared to a conventional electrospinning device. This is because, in the electrospinning device of the present invention, the high-voltage supply unit (100) and the air supply unit (500) are located outside the nozzle pack unit (600), allowing the nozzles (620) within the nozzle pack unit (600) to be positioned more densely. Through this, the nozzle pack unit (600) can be simplified, and cleaning and maintenance of the nozzle pack unit (600) are made easier. In addition, the electrospinning device of the present invention can position 200 to 250, 200 to 240, 200 to 230, 200 to 220, or 200 to 210 nozzles (620) within the nozzle pack (600), making it easier to mass-produce compared to conventional electrospinning devices.

[0143]

[0144] A discharge detection sensor (1100) is coupled to the nozzle pack (600) and is linked with the control unit (1000). FIG. 3 is a block diagram illustrating the configuration of the control unit (1000).

[0145] The discharge detection sensor (1100) includes an electric sensor (1110), an optical sensor (1120), and an acoustic sensor (1130). The electric sensor (1110) is a sensor for detecting changes in voltage and current, and detects sudden voltage drops and current spikes that occur during discharge. It includes a voltage sensor, a current sensor, a high-frequency signal detection circuit, etc.

[0146] The optical sensor (1120) is a sensor that detects light (arc or spark) generated from a discharge and can visually monitor the location and intensity of the discharge. It includes a UV sensor, a photodiode, a CCD camera, etc.

[0147] The acoustic sensor (1130) detects ultrasonic and high-frequency sounds generated during discharge, and analyzes the acoustic signal to determine the nature and magnitude of the discharge. It includes an ultrasonic microphone, a piezoelectric sensor, etc.

[0148]

[0149] Data collected from the discharge detection sensor (1100) is transmitted to the data collection unit (1200), and the data collection unit (1200) converts the collected data into a digital signal and performs storage and analysis.

[0150]

[0151] The signal processing unit (1300) derives the temporal and spatial characteristics of the discharge based on the collected signal. The collected data is processed using Fast Fourier Transform (FFT) and time-frequency analysis to derive the discharge pattern. In the case of normal discharge, voltage drops and current spikes occur regularly, whereas in the case of abnormal discharge, the voltage and current signals are irregular and have strong high-frequency components.

[0152]

[0153] The analysis unit (1400) identifies whether there is an abnormal discharge by comparing the normal discharge pattern stored in the database with the derived discharge pattern. For example, this can be identified using a machine learning-based algorithm.

[0154] When it is determined that an abnormal discharge pattern is present, the control unit (1500) can control the relay unit (2000) linked to the high-voltage supply unit (100). The relay unit (2000) is an electrical switch that controls the circuit of the high-voltage supply unit (100) using a low-voltage or low-current signal. Since the configuration regarding the relay is a known technology, a detailed description will be omitted. Through the above configuration, when it is determined that an abnormal discharge pattern is present, the high-voltage supply unit (100) will no longer supply voltage.

[0155]

[0156] If the warning unit (1600) determines that there is an abnormal discharge pattern, it immediately notifies the worker through a warning light, sound, and notification message.

[0157]

[0158] Through the configuration of the control unit (1000) as described above, abnormal discharge can be quickly detected and measures taken to prevent device damage and fire, the quality of electrospinning can be stabilized by maintaining a normal discharge pattern, and discharge data can be recorded and analyzed to contribute to the maintenance and performance optimization of the equipment, and the discharge pattern can be measured with high accuracy by combining electrical, optical, and acoustic sensors.

[0159]

[0160] The drying unit (700) is composed of a hot air drying device for removing volatile solvents contained in the solution and stably solidifying the spun fibers during the process in which the solution spun from the electrospinning device moves to the collection collector unit (800). The drying unit (800) plays a key role in improving the quality of the fibers and enhancing the safety of the working environment against solvent vapors.

[0161] The drying unit (700) may include a hot air generator, an air circulation device, and a control panel. The hot air generator is composed of a heater for generating high-temperature air and generally includes an electric heater coil or a gas heater. A temperature sensor and a PID controller are built in to maintain a uniform temperature of the air. For example, the air can be heated to an appropriate temperature (e.g., 40 to 120°C) required for the fiber to solidify.

[0162] The air circulation device is equipped with a fan or a blower to deliver hot air to the collector section (800). It may include a damper and an air velocity sensor to control the airflow. By distributing the hot air evenly, it acts evenly on the surface of the fibers, and by controlling the speed and direction of the airflow, it can improve the solidification and collection stability of the fibers.

[0163] The control panel is a control device that allows for real-time adjustment of hot air temperature, airflow speed, and other parameters. Temperature and airflow status can be monitored through a digital display.

[0164]

[0165] The collector section (800) is an area where fibers spun from an electrospinning device are collected, and it serves to maintain the shape of the fibers and ensure they are uniformly arranged. The collector section (800) is composed of a roller (810) and a belt (820) and is characterized by the application of a negative voltage to form a potential difference with the high voltage applied to the solution.

[0166] The roller (810) has a cylindrical structure and is mainly made of a highly durable metal material such as stainless steel or aluminum. The surface of the roller (810) is coated with an anti-static coating or a smooth surface treatment to increase the efficiency of fiber collection. Additionally, it supports and rotates the belt (820) to collect fibers evenly. It supports the uniform distribution of fibers and can adjust the rotation speed as needed.

[0167] The belt (820) has an infinite loop structure driven by a roller (810), and the surface of the belt is treated with a special coating to ensure good adhesion of fibers. It continuously collects fibers to maximize production efficiency and moves at a constant speed to evenly distribute the spun fibers. After collecting the fibers, the collected fibers are transferred to the next process (e.g., drying, packaging).

[0168] A negative voltage is applied to the collector (800) to create a potential difference with the radiated solution. Generally, a voltage between -5 kV and -30 kV is used to create an electric field that allows the radiated solution to move stably to the collector (800).

[0169]

[0170] A nanofiber filter was manufactured in the following manner using the electrospinning apparatus of the present invention described above:

[0171] Polyethersulfone (PES) was dissolved in a mixed solution of DMAc, DMSO, and ethyl acetate in a weight ratio of 3:5:2 to prepare a spinning solution containing 15 wt% of PES.

[0172] The above spinning solution is injected into the electrospinning device described above, at 31°C to 33°C, humidity 50%, spinning solution spray speed 0.2 m / min, voltage 40 to 60 Kv, and 0.5 kg / cm² 2 Electrospinning was carried out under air injection conditions. A melt-blown nonwoven fabric was used as a support, and a nanofiber web was formed by electrospinning on one surface of the support. The electrospinning pack of the electrospinning device used included six 25 gauge (G) electrospinning nozzles.

[0173] After forming a nanofiber web under the manufacturing conditions described above, the results of measuring the average diameter of the nanofibers are as shown in Fig. 5 and Table 4 below:

[0174] NODiameter(nm)12662234330241695188617272618157917610251Min169Max302Avg.228

[0175] According to the experimental results above, the average diameter of the nanofibers was measured to be 228 nm, the minimum diameter 169 nm, and the maximum diameter 302 nm. It was confirmed that it is possible to produce nanofibers with uniform diameters using the electrospinning device of the present invention.

[0176] Although the detailed description of the present invention has been explained with reference to preferred embodiments, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and technical scope of the invention as set forth in the claims below. Accordingly, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be determined by the claims.

[0177] 100 : High voltage supply,

[0178] 200 : Solution supply unit,

[0179] 300 : Mixer section,

[0180] 500 : Air supply unit,

[0181] 600 : Nozzle pack section,

[0182] 700 : Drying section,

[0183] 800 : Collector Department,

[0184] 900 : Temperature sensor.

[0185] The present invention relates to a technology for improving the safety of an electrospinning device, and in particular to an electrospinning device including various safety devices and structures to prevent safety accidents caused by discharge and overheating and to reduce the risk of fire in a device that uses high voltage to spin a fiber raw material solution.

Claims

1. A solution supply unit that supplies a solution in which a fiber raw material is dissolved; A high-voltage supply unit that imparts an electric charge to the above solution; A nozzle pack portion for discharging the above-mentioned charged solution; and A discharge detection sensor coupled to the nozzle pack portion to measure a discharge pattern; comprising Electrospinning device with improved safety.

2. In Paragraph 1, The above discharge detection sensor is linked with a control unit, The detected discharge pattern is compared with a preset normal discharge pattern. Electrospinning device with improved safety.

3. In Paragraph 2, The above discharge detection sensor is Includes electric sensors, optical sensors, and acoustic sensors Electrospinning device with improved safety.

4. In Paragraph 3, The above control unit is, A data collection unit that converts data collected through the above-mentioned electric shock sensor into a digital signal and stores it. Electrospinning device with improved safety.

5. In Paragraph 4, The above control unit is, A signal processing unit that derives a discharge pattern by processing the signal collected through the data collection unit using FFT and time-frequency analysis; Electrospinning device with improved safety.

6. In Paragraph 5, The above control unit is, The apparatus includes an analysis unit that identifies abnormal discharge by comparing a pre-set normal discharge pattern with a derived discharge pattern. Electrospinning device with improved safety.

7. In Paragraph 6, The above control unit is, A control unit that controls a relay unit linked to the high-voltage supply unit to cut off the power of the high-voltage supply unit when an abnormal discharge is detected; Electrospinning device with improved safety.

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