Spinning cloth air permeability on-line monitoring system and electrostatic spinning equipment using same

Abstract

The present application relates to the field of intelligent processing equipment in high-end equipment manufacturing industry, new chemical fibers and functional textile materials in new material industry, and particularly relates to a kind of spinning cloth air permeability online monitoring system and electrospinning equipment using it.The spinning cloth air permeability online monitoring system includes: roller, is arranged above spinning cloth, its axis is perpendicular to the direction of spinning cloth transmission, its inside hollow, its surface is provided with N rows of air jet holes, each row of air jet holes includes: M air jet holes arranged along the direction parallel to the axis of roller;Air jet device, its air outlet is connected to the hollow inside of roller;Pressure sensing system, including: S air pressure sensing units arranged below spinning cloth;Control system, using the air pressure value obtained by sensing S air pressure sensing units to judge the air permeability of spinning cloth.The present application can evaluate the quality standard of spinning cloth in real time and continuously, and improve the intelligent level of air permeability test.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of intelligent processing equipment in high-end equipment manufacturing industry, new chemical fibers and functional textile materials in new material industry, and the like, and particularly relates to a spinning cloth air permeability online monitoring system and an electrospinning device applying the same. BACKGROUND

[0002] In recent years, with the rapid development of nanotechnology, electrospinning technology has attracted extensive attention. Since the 21st century, the application of nanofibers has been further expanded, including biological, medical, textile and clothing, and other high-tech fields. Researchers have shifted from early fiber preparation and characterization to understanding the formation process and mechanism of electrospinning. Compared with other methods of obtaining fibers, electrospinning technology has the advantages of wide selection of raw materials, simple equipment and strong controllability of time. Therefore, it has become the object of researchers, and a hot wave of electrospinning theory and experiments has been triggered.

[0003] However, in order to realize industrialization, large-scale and wide application of nanofiber membranes prepared by electrospinning technology, further online quality monitoring is needed. The air permeability of nanofiber membranes is one of the key indicators that determine their quality. At present, the relatively mature online air permeability monitoring system for nanofiber membranes in China is still in a relatively blank stage, and there is no relevant national standard to follow. The data obtained by the conventional head-tail cutting monitoring method is not representative, and therefore there is an urgent need to develop a system that can monitor the quality in real time. SUMMARY

[0004] (I) Technical problems to be solved

[0005] The present application expects to at least partially solve one of the above technical problems.

[0006] (II) Technical solutions

[0007] In a first aspect of the present application, a spinning cloth air permeability online monitoring system is provided. The spinning cloth air permeability online monitoring system comprises:

[0008] a roller, disposed above the spinning cloth, with its axis perpendicular to the direction of transmission of the spinning cloth, hollow inside, and provided with N rows of air jet holes on its surface, N≥1, each row of air jet holes comprising: M air jet holes arranged in a direction parallel to the axis of the roller, M≥2;

[0009] an air jet device, with its air outlet connected to the hollow interior of the roller;

[0010] a pressure sensing system, comprising: S air pressure sensing units disposed below the spinning cloth, S≥1;

[0011] The control system is connected to the S air pressure sensing units, and the air permeability of the spun fabric is determined by the air pressure values sensed by the S air pressure sensing units.

[0012] In some embodiments of the present application, the air jet device sprays the pulsed air flow into the hollow interior of the drum; the control system determines the air permeability of the spun fabric by the pulsed electric signals of the S air pressure sensing units.

[0013] In some embodiments of the present application, the air jet device sprays the pulsed air flow into the hollow interior of the drum when the air jet holes are aligned with the spun fabric.

[0014] In some embodiments of the present application, the air jet device is a pulsed air flow generator, and the air outlet of the air jet device is connected to the hollow interior of the drum through a pipeline.

[0015] In some embodiments of the present application, the air jet device comprises: an air inlet motor; a pressure regulating valve, the air inlet of which is connected to the air outlet of the air inlet motor through a pipeline; an air jet valve, the air inlet of which is connected to the air outlet of the pressure regulating valve through a pipeline, and the air outlet of which is connected to the hollow interior of the drum through a pipeline; and an air flow control system, the signal input end of which is connected to the control system, and the signal output end of which is connected to the control end of the air jet valve, thereby controlling the opening degree and switching frequency of the air jet valve.

[0016] In some embodiments of the present application, the surface of the drum is provided with one row of air jet holes, and the one row of air jet holes comprises 20-40 air jet holes; the air jet frequency of the air jet device is consistent with the rotation frequency of the drum.

[0017] In some embodiments of the present application, the gas flow of the pulsed air flow is between 10-50 dm 3 / min.

[0018] In some embodiments of the present application, the switching frequency of the pulsed air flow is between 5-10 times per second.

[0019] In some embodiments of the present application, the control system internally pre-stores the relationship curve between the air permeability and the current, and executes the following control program:

[0020] Step A: receiving the qualified value of the air permeability set by the user;

[0021] Step B: determining the qualified range of the current according to the relationship curve between the air permeability and the current;

[0022] Step C: when the pulsed electric signals of the S air pressure sensing units are within the qualified range of the current, it is determined that the air permeability of the spun fabric is qualified; otherwise, it is determined that the spun fabric is unqualified.

[0023] In some embodiments of the present application, the pressure sensing system comprises 20-40 air pressure sensing units arranged in parallel with the axis of the roller, a signal collector connected to the 20-40 air pressure sensing units at the signal collection port and connected to the control system at the signal output port.

[0024] In some embodiments of the present application, the air pressure sensing unit is arranged directly below the axis of the roller.

[0025] In some embodiments of the present application, the air pressure sensing unit is a thin film sensing unit.

[0026] In some embodiments of the present application, the air pressure sensing unit is a piezoresistive sensing unit, each piezoresistive sensing unit has an area ranging from 5-20 cm 2 , a current of 4-20 mA, a range of 0-100 kPa, and an accuracy of ≤0.2%.

[0027] In the second aspect of the present application, an electrospinning device is provided. The electrospinning device comprises:

[0028] a spinning box, an inlet being arranged at the upstream side of the spinning box, and an outlet being arranged at the downstream side of the spinning box;

[0029] the spinning fabric permeability online monitoring system as above;

[0030] wherein the roller is arranged above the outlet, the pressure sensing system is arranged below the outlet, and the spinning fabric passes between the roller and the pressure sensing system.

[0031] In some embodiments of the present application, further comprising: a conveying frame arranged between the inlet and the outlet in the spinning box; an electrospinning device arranged above the conveying frame in the spinning box; a base material unwinder and a fabric winder arranged outside the inlet and the outlet, respectively; wherein the first end of the roller is connected to the spinning box through a drive shaft; the gas outlet of the air jet device is connected to the second end of the roller through a pipeline, and a bearing is arranged between the pipeline and the second end of the roller; wherein the spinning base material is drawn out from the base material unwinder, enters the spinning box from the inlet, is guided out of the spinning box through the conveying frame and the outlet, and is wound by the fabric winder, during which the nanofibers sprayed by the electrospinning device are deposited on the spinning base material to form the spinning fabric.

[0032] (III) Beneficial effects

[0033] From the above technical solutions, the present application has at least one of the following beneficial effects relative to the prior art:

[0034] (1) By monitoring the induced current generated by the air pressure passing through the tested spun fabric online, its air permeability can be monitored accurately and quickly, and the quality standards of the spun fabric can be evaluated in real time and continuously, which improves the intelligence level of air permeability testing and increases production efficiency.

[0035] (2) Compared with the compressed closed system jet device, the roller jet device can ensure the integrity of nanofibers and zero airflow loss. At the same time, compared with jet monitoring of the whole area, the multi-hole jet monitoring has higher accuracy. In addition, the number of jet holes can be adjusted or the pressure parameters and gas flow rate of the air intake can be set according to the needs. The equipment is simple to manufacture, easy to operate and highly stable.

[0036] (3) The current-time curve obtained by the signal processing unit after analyzing and processing the air permeability data can be used to identify the quality of the spinning film online and intuitively, which reduces the time and cost of manual monitoring and can meet the needs of large-scale industrial production of nanofiber fabrics.

[0037] (4) Compared with uniform airflow monitoring, the pulse airflow monitoring used in this embodiment has the following advantages: ① The monitoring is more accurate. Uniform airflow monitoring obtains a stable airflow, making it difficult to distinguish the presence or absence of a signal. At the same time, it is impossible to amplify the useful signal through normalization or other processing methods. Pulse airflow monitoring makes it easy to distinguish the presence or absence of a signal, avoiding the impact of defects caused by uniform airflow monitoring on the breathability of the overlapping fabric. It also provides convenience for subsequent signal processing, such as normalization. ② The monitoring effect is better. The jet frequency of pulse airflow can be adjusted according to the conveying speed of the spun fabric, avoiding problems such as deformation or damage to the spun fabric caused by excessive jetting when the conveying speed of the spun fabric is low. ③ It is highly efficient and energy-saving. Pulse airflow monitoring consumes less air, which can save a lot of energy and avoid the energy consumption and wear on the jetting device caused by uniform airflow monitoring, thus reducing operating costs. Attached Figure Description

[0038] Figure 1 This is a horizontal cross-sectional view of an electrospinning device using an online monitoring system for the air permeability of spun fabrics, as described in an embodiment of the present invention.

[0039] Figure 2 for Figure 1 The view shown is of the direction of the discharge port of the electrospinning equipment.

[0040] Figure 3 for Figure 1 The diagram shows the structure of the air jet device in the electrospinning equipment.

[0041] Figure 4 for Figure 1 The diagram shows the structure of the pressure sensing system in the electrospinning equipment.

[0042] Figure 5For Figure 1 The air permeability-current relationship curve pre-stored in the control system of the electrospinning equipment shown in FIG.

[0043] Figure 6 For Figure 1 The current change graph received by the control system of the electrospinning equipment shown in FIG. DETAILED DESCRIPTION

[0044] The purpose of the present application is to provide an air permeability online monitoring system for industrialized production of electrospinning, which can quickly and accurately test the air permeability of the measured spinning cloth, improve the intelligent level of the electrospinning equipment, and improve the quality of the electrospinning cloth.

[0045] In order to make the purpose, technical scheme and advantages of the present application clearer and more apparent, the following further describes the present application in combination with specific embodiments and with reference to the accompanying drawings.

[0046] In the first aspect of the present application, a spinning cloth air permeability online monitoring system is provided. On this basis, the second aspect of the present application provides an electrospinning equipment applying the spinning cloth air permeability online monitoring system. For ease of understanding, the following mainly describes the electrospinning equipment, but those skilled in the art should understand that the spinning cloth air permeability online monitoring system therein can be independently implemented for manufacturing, using, selling, offering for sale, importing, etc., and is also within the protection scope of the present application.

[0047] Figure 1 FIG. 4 is a horizontal sectional view of the electrospinning equipment applying the spinning cloth air permeability online monitoring system according to the embodiment of the present application. Figure 2 For Figure 1 The view of the electrospinning equipment shown in FIG.

[0048] As Figure 1 and Figure 2 The electrospinning equipment of the present embodiment includes a spinning box 10, an upstream side of which is provided with a feeding port 11 and a downstream side of which is provided with a discharging port 12; a conveying frame 20, which is arranged in the spinning box between the feeding port and the discharging port; an electrospinning device 30, which is arranged in the spinning box above the conveying frame; a base material unwinding machine 41 and a cloth winding machine 42, which are respectively arranged outside the feeding port and the discharging port, wherein the spinning base material is led out from the base material unwinding machine 41, enters the spinning box from the feeding port 11, is led out via the conveying frame 20 and the discharging port 12, and is wound by the cloth winding machine 42. During this period, the nanofibers sprayed by the electrospinning device 30 are deposited on the spinning base material to form a spinning cloth.

[0049] Please continue to refer to Figure 1 and Figure 2The electrostatic spinning device also comprises a spinning cloth air permeability online monitoring system for monitoring the air permeability of the spinning cloth after electrospinning. Specifically, the spinning cloth air permeability online monitoring system comprises: a roller 51 arranged above the spinning cloth, the axis of which is perpendicular to the direction of transmission of the spinning cloth, the inside of which is hollow, and the surface of which is provided with N rows of air injection holes, N ³ 1, each row of air injection holes comprising: M air injection holes 51c arranged in a direction parallel to the axis of the roller, M ³ 2; an air injection device 52, the air outlet of which is connected to the hollow inside of the roller; a pressure sensing system 53 comprising: S air pressure sensing units 53a arranged below the spinning cloth, S ³ 1; a control system 54 connected to the air injection device and the S air pressure sensing units, which controls the air injection device to output air, and judges the air permeability of the spinning cloth by using the air pressure values obtained by the S air pressure sensing units; wherein the roller is arranged above the discharge port, the pressure sensing system is arranged below the discharge port, and the spinning cloth passes between the two.

[0050] It can be seen that, by monitoring the induced current generated by the air pressure passing through the measured spinning cloth, the air permeability of the spinning cloth can be accurately and quickly monitored, and the quality standard of the spinning cloth can be continuously evaluated in real time, thereby improving the intelligent level of the air permeability test and improving the production efficiency.

[0051] The various components of the electrostatic spinning device of the present embodiment will be described in detail below.

[0052] In the present embodiment, the spinning box 10 is in the shape of a rectangular cuboid, and has a feeding port 11 and a discharging port 12 on two sides. The feeding port 11 is 2m long and 0.5m wide, and the discharging port 12 comprises a rectangular platform that is 2m long and 1.5m wide.

[0053] Those skilled in the art should understand that the shape of the spinning box, the shape / dimensions of the feeding port and the discharging port, etc. can be adjusted according to actual production needs, and are not limited to the shapes and dimensions listed above.

[0054] The conveying frame 20 is located between the feeding port 11 and the discharging port 12. On the outside of the spinning box, on the upstream side of the feeding port 11, a base material unwinding machine 41 is arranged. On the outside of the spinning box, on the downstream side of the discharging port, a cloth winding machine 42 is arranged. Above the conveying frame 20, an electrostatic spinning device 30 is installed. The electrostatic spinning device 30 comprises a high-voltage power supply, a spraying device, etc. (not shown in the figure). The spraying device is composed of multiple groups of injectors. The spinning base material is placed on the drum of the base material unwinding machine 41, and is conveyed at a conveying speed of 1-5mm / s through the conveying belt of the conveying frame 20 to the cloth winding machine 42 through the electrostatic spinning device 30. During this process, the nanofibers sprayed by the electrostatic spinning device 30 are deposited on the spinning base material to form a spinning cloth.

[0055] Please refer to Figure 2The drum 51 is in a cylindrical shape and is arranged above the discharge port. The first end of the drum 51 is connected to the spinning beam 10 through a driving shaft 51a, and the second end is connected to the air inlet pipe. The driving shaft 51a is fixed on the box body and is driven by a power mechanism to drive the drum 51 to rotate. At the second end of the drum, a bearing 51b is arranged outside the air inlet pipe to ensure that the air inlet pipe is fixed when the drum rotates.

[0056] Those skilled in the art should understand that the position of the drum, the installation and fixing mode, and the driving mode are only examples, and those skilled in the art can adjust them based on actual production needs, which are also within the protection scope of the present application.

[0057] A row of 20-40 air injection holes 51c is arranged on the side surface of the drum 51, and the area of the air injection hole is 5-20 cm 2 The row of air injection holes is arranged in a direction parallel to the axis of the drum.

[0058] It can be seen that, compared with the pressurized closed system air injection device, the drum air injection device can ensure the integrity of the nanometer spinning fiber and zero loss of airflow. Compared with the whole area air injection monitoring, the multi-hole air injection monitoring has higher precision, and the number of air injection holes, the pressure parameters and the gas flow of the air inlet can be adjusted according to the requirements. The equipment is simple to manufacture, easy to operate, and has high stability.

[0059] It should be particularly pointed out that, for the sake of simplifying the control process and data processing, the present embodiment is provided with a row of air injection holes on the drum. However, in other embodiments of the present application, 2 rows, 3 rows, 4 rows or more rows of air injection holes can be provided, and the control system can be set according to the data processing program. The present application can also be realized, and it is also within the protection scope of the present application. However, in this case, the adjustment of the air injection frequency and the interference factors before and after different air injection processes need to be considered, and the control program and the data processing program are more complex than the present embodiment.

[0060] Figure 3 For Figure 1 The structure diagram of the air injection device in the electrospinning equipment is shown in FIG. 1. Please refer to Figure 1 and Figure 3 In the present embodiment, the air injection device 52 comprises:

[0061] An air inlet motor 52a;

[0062] A pressure regulating valve 52b, the air inlet thereof is connected to the air outlet of the air inlet motor through a pipe;

[0063] An air injection valve 52c, the air inlet thereof is connected to the air outlet of the pressure regulating valve through a pipe, and the air outlet thereof is connected to the hollow interior of the drum through a pipe;

[0064] An air flow control system 52d is connected to the control end of the air jet valve, and controls the opening degree and switching frequency of the air jet valve.

[0065] The air flow control system can be directly set by a user or be set by the control system. In this embodiment, the air flow control system is a PLC control system, and the signal input end of the PLC control system is connected to the control system 54, and the opening degree and switching frequency set by the user are input by the control system.

[0066] The air inlet motor 52a is used to generate air pressure, and the air pressure is adjusted to a preset air pressure by the pressure regulating valve 52b. When the air jet hole 51c touches the nanofiber membrane, the gas is jetted out. The opening degree of the air jet valve 52c is set by the PLC control system to adjust the gas flow and switching frequency, and the air jet frequency is consistent with the rotation frequency of the roller and the frequency of the conveying belt.

[0067] Specifically, in this embodiment, the roller rotates along the spinning cloth conveying direction, and the rotation frequency is 5 seconds / revolution. The opening degree and switching frequency of the air jet valve 52c are controlled by the PLC control system to control the gas flow to be 20 dm 3 / min, and the air jet frequency is 5 seconds / time. However, the present application is not limited thereto. In some other embodiments of the present application, the gas flow of the pulse air flow is between 10-50 dm 3 / min; and the switching frequency of the pulse air flow is between 5-10 times / second. Of course, the person skilled in the art can also adjust it according to the actual production needs, which will not be described here.

[0068] The person skilled in the art should understand that in order to output the pulse air flow, in addition to the implementation mode of the “PLC control system controlling the air jet valve” as described above, a pulse air flow generator can also be used, as long as the air outlet end of the pulse air flow generator is connected to the hollow interior of the roller. The structure is simpler, but the cost is relatively high.

[0069] Figure 4 For Figure 1 The structure schematic diagram of the pressure sensing system in the electrospinning equipment is shown in FIG. 5. Figure 2 and Figure 4 As shown in FIGS. 5 and 6, the pressure sensing system 53 includes a film air pressure sensing unit 53a and a signal collector 53b.

[0070] The film air pressure sensing unit 53a is fixed on the discharge port, and 20-40 sensing units are distributed thereon. The sensing unit is a piezoresistive structure. The area of each sensing unit is in the range of 5-20 cm 2 , the current is 4-20 mA, the range is 0-100 kPa, and the accuracy is ≤0.2%.

[0071] Those skilled in the art should understand that although the sensing unit in the embodiment adopts a piezoresistive structure, other types of sensing units, such as a piezocapacitive sensing unit, can also be adopted in other embodiments of the application, and the application can also be implemented. Although the air pressure sensing unit in the embodiment obtains a current signal, an air pressure sensing unit outputting a voltage signal can also be adopted in other embodiments of the application. In addition, the number of sensing units, specific parameters, etc. can be adjusted according to actual production needs, and are not limited to the above embodiment.

[0072] For the signal collector 53b, the sensing signal collection port is connected to the 20-40 sensing units, and the signal output port is connected to the control system. The signal collector 53b converts the pressure of the gas through the measured material into an electrical signal and transmits it to the control system 54.

[0073] The control system 54 includes a processor, a memory, and a display screen. The memory includes an electrical signal dynamic display program for the processor to run. By statistically storing the current intensity at different times, the relationship between the air permeability and the current is compared, and the processing program determines the air permeability of the spunlaid fabric.

[0074] Figure 5 For Figure 1 The air permeability-current relationship curve pre-stored in the control system of the electrospinning device is shown. The relationship curve is obtained from previous experiments. Since the relationship curve is pre-stored in the control system, after receiving the user-set air permeability qualified value, the qualified range of the current pulse can be calculated.

[0075] It can be seen that the current-time curve obtained by the signal processing unit analyzing and processing the air permeability data can intuitively identify the quality of the spunlaid film online, reducing the time and cost of manual monitoring, and can meet the large-scale industrial production of nanofiber fabrics.

[0076] Specifically, the control system pre-stores the air permeability-current relationship curve, which executes the following control program:

[0077] Step A, receiving user-set values, including:

[0078] Sub-step A1, receiving a user-set air permeability qualified value;

[0079] Sub-step A2, receiving user-set values of the opening degree and the switching frequency of the air jet valve;

[0080] Those skilled in the art should understand that the above user-set values can also be default values set by the user in advance, which are also within the protection scope of the application.

[0081] Step B, test preparation, including:

[0082] Sub-step B1, control the air jet device to output air flow according to preset gas flow and frequency.

[0083] Specifically, the air inlet motor 52a is started, the constant air pressure is adjusted through the adjusting valve 52b, the PLC control system controls the opening degree and switching frequency of the air jet valve 52c, and the gas flow is controlled in the range of 0-50 dm 3 / min, and the air flow produced by the air inlet motor 52a is blown vertically to the spinning cloth at a frequency of 5-10 seconds / time, and the pressure after the air flow passes through the spinning cloth is received by the film air pressure sensing unit 53a.

[0084] Sub-step B2, determine the current qualified range according to the relationship curve between air permeability and current;

[0085] Sub-step B3, control the base material unwinding machine 41 and the cloth winding machine 42, and the electrospinning device 30 to work, and start the electrospinning process.

[0086] The specific implementation of this step can refer to the description of the related prior art, which will not be repeated here.

[0087] Sub-step B4, control the power device to drive the driving shaft to rotate, and then drive the roller to rotate.

[0088] The roller rotates along the conveying direction of the electrospinning film at a rotation frequency of 5 seconds / revolution, and the roller rotates to the upper side of the nanometer film to perform light touch air jet, and the air jet frequency is consistent with the rotation frequency of the roller.

[0089] Step C, when the pulse current signals of the S air pressure sensing units are within the current qualified range, it is judged that the air permeability of the spinning cloth is qualified; otherwise, it is judged that the spinning cloth is unqualified.

[0090] In this embodiment, when the sensing unit surface has no pressure, its resistance is very high, and when the sensing unit senses pressure, the resistance gradually decreases. At the same time, the pressure signal collected by the collector is converted into an electrical signal data and transmitted to the control system 54.

[0091] Figure 6 For Figure 1 The current change graph at different times received by the control system of the electrospinning device shown in FIG. 6. Figure 6 In FIG. 6, the abscissa is time, in seconds (s); the ordinate is pulse current intensity, in milliampere (mA). As shown in FIG. 6, when the sensing unit surface has no pressure, its resistance is very high, and when the sensing unit senses pressure, the resistance gradually decreases. At the same time, the pressure signal collected by the collector is converted into an electrical signal data and transmitted to the control system 54. Figure 6It can be seen that, in the case of uniform and flat electrospinning nanofiber membrane, the electrical signal obtained by the sensing unit is a generally regular pulse electrical signal. When the nanofiber membrane is too thick at some places, the amplitude of the pulse electrical signal will be greatly reduced; when the nanofiber membrane is too thin at some places, the amplitude of the pulse electrical signal will be greatly increased. Thus, the uniformity of the electrospinning nanofiber membrane can be perceived by analyzing the amplitude change of the pulse electrical signal.

[0092] Specifically, when the air permeability is in the range of 30-50 mm / kPa.min, that is, the current intensity is all in the range of 15-18 mA, it indicates that the batch of spunlaced fabric is qualified, and at this time the control system display screen displays the word "qualified". If the current exceeds 15-18 mA, it indicates that the batch of spunlaced fabric is unqualified, and at this time the control system display screen displays the word "unqualified".

[0093] In this embodiment, the jet device sprays pulse airflow, so that the current obtained by the control system is a regular pulse electrical signal. By analyzing the change of the regular pulse electrical signal, the air permeability of the nanofiber membrane in the spunlaced fabric can be known. In other embodiments of the present application, the jet device can also spray uniform airflow, so as to keep the air pressure above the spunlaced substrate dynamically stable. At this time, the current signal obtained by the control system is a smooth current. If the smooth current changes suddenly, it also indicates that the air permeability of the nanofiber membrane has changed, and the present application can also be achieved.

[0094] However, compared with uniform airflow monitoring, the pulse airflow monitoring in this embodiment has the following advantages:

[0095] ①More accurate monitoring

[0096] Uniform airflow monitoring obtains a smooth airflow, and it is difficult to distinguish the presence or absence of the signal. At the same time, it is impossible to amplify the useful signal by normalization and other processing methods. Pulse airflow monitoring is easy to distinguish the presence or absence of the signal, avoids the influence of defects on the air permeability of the overlapped fabric caused by uniform airflow monitoring, and provides convenience for subsequent signal processing, such as normalization.

[0097] ②Good monitoring effect

[0098] The pulse airflow spraying frequency can be adjusted according to the conveying speed of the spunlaced fabric, which avoids the problem of deformation or damage of the spunlaced fabric caused by excessive air spraying when the conveying speed of the spunlaced fabric is low.

[0099] ③High efficiency and energy saving

[0100] Pulse airflow monitoring consumes less air, which can save a lot of energy, avoid the consumption of energy and the wear and tear of the jet device caused by uniform airflow monitoring, and reduce the operating cost.

[0101] The electrostatic spinning device in the present application is described in detail above, and based on the above description, those skilled in the art should have a clear understanding of the spinning cloth air permeability online monitoring system in the present application, which will not be described again here.

[0102] So far, the various embodiments of the present application have been introduced. According to the above description, those skilled in the art should have a clear understanding of the present application.

[0103] It should be further noted that the direction terms mentioned in the embodiments, such as "up", "down", "front", "back", "left", "right", "inner", "outer", etc., are only the directions of the drawings, and are not intended to limit the protection scope of the present application. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Moreover, the shapes and sizes of the components in the drawings do not reflect the true size and ratio, but only illustrate the content of the embodiments of the present application.

[0104] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0105] It should be noted that, unless explicitly stated to the contrary, the numerical parameters in the specification and claims of the present application can be approximate values, which can be changed according to the content of the present application. Specifically, all numbers indicating the content of composition, reaction conditions, etc. recorded in the specification and claims should be understood as being modified by the term "about" in all cases, which means that it contains a variation of ±10% from the specific number in some embodiments.

[0106] Those skilled in the art should understand that in the claims and specification of the present application, the word "comprising" does not exclude the presence of elements (or steps) not listed in the claims. The word "one" or "an" before an element (or step) does not exclude the presence of multiple such elements (or steps).

[0107] For certain implementation manners, if they are not the key contents of the present application and are well known to those skilled in the art, they are not described in detail in the drawings or the text of the specification due to the limitation of the volume, and can be understood with reference to the related prior art. Moreover, the purpose of providing the above examples is only to enable the present application to meet the legal requirements, and the present application can be implemented in many different forms, and should not be interpreted as being limited to the examples described herein. In addition, the above definitions of elements and methods are not limited to the various specific structures, shapes or manners mentioned in the examples, and those skilled in the art can make simple changes or replacements.

[0108] Similarly, it should be understood that, in order to simplify the present application, various features of the present application are sometimes grouped together in a single embodiment, figure, or description of related elements in the above description of exemplary embodiments of the present application. However, the method of the present application should not be interpreted as reflecting the intention that the claimed application requires more features than those explicitly recited in each claim. Rather, as reflected by the claims, each aspect of the application is based on less than all the features of the preceding single embodiment. Moreover, the embodiments can be mixed and used with each other or other embodiments based on design and reliability considerations, i.e. the technical features in different embodiments can be freely combined to form more embodiments. Therefore, the claims following the specific embodiments are hereby expressly incorporated into the specific embodiments, wherein each claim itself is a separate embodiment of the present application.

[0109] The above various specific embodiments have been described in detail to explain the purpose, technical means and beneficial effects of the present application, and it should be understood that the purpose of the detailed description is to enable those skilled in the art to understand the present application more clearly, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An online monitoring system for the air permeability of spun fabrics, characterized in that, The system comprises: a roller arranged above the spinning fabric, the axis of the roller being perpendicular to the direction of the spinning fabric transmission, the roller being hollow inside, and the surface of the roller being provided with N rows of air jet holes, N≥1, each row of air jet holes comprising M air jet holes arranged in a direction parallel to the axis of the roller, M≥2; an air jet device, the air outlet of the air jet device being connected to the hollow inside of the roller; a pressure sensing system comprising S air pressure sensing units arranged below the spinning fabric, S≥1; a control system, the control system being signal-connected to the S air pressure sensing units, and the control system being configured to determine the air permeability of the spinning fabric by using the air pressure values sensed by the S air pressure sensing units; wherein the roller is configured to rotate along the direction of the spinning fabric transmission, the air jet device is configured to inject a pulse air flow into the hollow inside of the roller, and the control system is configured to determine the air permeability of the spinning fabric by using the pulse electric signals of the S air pressure sensing units.

2. The on-line monitoring system for air permeability of a spunlace fabric according to claim 1, wherein, The air jet device is configured to inject a pulse air flow into the hollow inside of the roller when the air jet holes of the air jet device are aligned with the spinning fabric, and wherein: the air jet device is a pulse air flow generator, the air outlet of the pulse air flow generator being connected to the hollow inside of the roller through a pipeline; or the air jet device comprises: an air inlet motor; a pressure regulating valve, the air inlet of the pressure regulating valve being connected to the air outlet of the air inlet motor through a pipeline; an air jet valve, the air inlet of the air jet valve being connected to the air outlet of the pressure regulating valve through a pipeline, and the air outlet of the air jet valve being connected to the hollow inside of the roller through a pipeline; an air flow control system, the signal input end of the air flow control system being connected to the control system, and the signal output end of the air flow control system being connected to the control end of the air jet valve, the air flow control system being configured to control the opening degree and the switching frequency of the air jet valve.

3. The system according to claim 1, wherein: the surface of the roller is provided with one row of air jet holes, the one row of air jet holes comprising 20-40 air jet holes; the air jet frequency of the air jet device is consistent with the rotation frequency of the roller.

4. The system according to claim 1, wherein: the gas flow of the pulse gas flow is between 10-50 dm 3 / min; and / or the switching frequency of the pulse air flow is between 5-10 times per second.

5. The on-line monitoring system for air permeability of a spunlaid fabric according to claim 1, wherein, the control system is internally pre-stored with a relationship curve between the air permeability and the electric current, and the control system is configured to execute the following control program: step A, receiving the air permeability qualified value set by a user; step B, determining the qualified range of the electric current according to the relationship curve between the air permeability and the electric current; step C, when the pulse electric signals of the S air pressure sensing units are within the qualified range of the electric current, determining that the air permeability of the spinning fabric is qualified; otherwise, determining that the air permeability of the spinning fabric is unqualified. the pressure sensing system comprises:

6. The on-line monitoring system for air permeability of a spunlaid fabric according to claim 1, wherein, 20-40 air pressure sensing units, the 20-40 air pressure sensing units being arranged in a direction parallel to the axis of the roller; a signal collector, the sensing signal collection port of the signal collector being signal-connected to the 20-40 air pressure sensing units, and the signal output port of the signal collector being connected to the control system.

7. The system according to claim 6, wherein: the air pressure sensing units are arranged directly below the axis of the roller; and / or the air pressure sensing units are thin film sensing units.

8. The system according to claim 6, comprising: a spinning beam, the upstream side of the spinning beam being provided with a feeding port, and the downstream side of the spinning beam being provided with a discharging port. The air pressure sensing units are piezoresistive sensing units, each of which has an area ranging from 5-20 cm 2 , current 4-20 mA, range 0-100 kPa, accuracy ≤0.2%.

9. An electrospinning apparatus, characterized by, ​ ​ The system for monitoring the air permeability of a spun fabric on line according to any one of claims 1 to 8; The drum is arranged above the discharge port, and the pressure sensing system is arranged below the discharge port, with the spun fabric passing between the drum and the pressure sensing system.

10. The electrospinning apparatus of claim 9, wherein, Further comprising: A conveying frame arranged in the spinning box between the inlet port and the discharge port; An electrospinning device arranged in the spinning box above the conveying frame; A base material unwinder and a fabric winder arranged outside the inlet port and the discharge port, respectively; The first end of the drum is connected to the spinning box via a drive shaft, and the air outlet of the air jet device is connected to the second end of the drum via a pipe, with a bearing arranged between the pipe and the second end of the drum; The base material is unwound from the base material unwinder, enters the spinning box from the inlet port, is guided out of the spinning box via the conveying frame and the discharge port, and is wound by the fabric winder, during which the nanofibers sprayed by the electrospinning device are deposited on the base material to form the spun fabric.

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