阅读说明：本技术 制备多层纤维膜的近场直写装置及多层纤维膜制备方法 (Near-field direct writing device for preparing multilayer fiber film and preparation method of multilayer fiber film ) 是由 王晗 李申 史磊 梁祝业 康欢 薛增喜 于 2019-10-24 设计创作，主要内容包括：本发明涉及静电纺丝领域,具体涉及制备多层纤维膜的近场直写装置及多层纤维膜制备方法,包括高压电源、接收系统、供液系统、控制系统、针头切换系统、视觉检测系统；针头切换系统与供液系统通过输液管连接,控制系统分别与供液系统、高压电源、接收系统、针头切换系统以及视觉检测系统电连接,视觉检测系统用于拍摄接收板上的纤维图片,控制系统根据纤维图片计算得到当前纤维膜尺寸,同时将当前纤维膜尺寸与预设纤维膜尺寸进行大小比较,根据比较结果控制供液系统、针头切换系统以及接收系统工作,采用视觉检测系统控制针头的切换和纺丝溶液的切换,自动完成多层纤维膜材料的制备,减少因为再定位问题产生误差的可能性。(The invention relates to the field of electrostatic spinning, in particular to a near-field direct-writing device for preparing a multilayer fiber film and a preparation method of the multilayer fiber film, wherein the near-field direct-writing device comprises a high-voltage power supply, a receiving system, a liquid supply system, a control system, a needle head switching system and a visual detection system; the needle switching system is connected with the liquid supply system through a liquid conveying pipe, the control system is respectively electrically connected with the liquid supply system, the high-voltage power supply, the receiving system, the needle switching system and the visual detection system, the visual detection system is used for shooting a fiber picture on the receiving plate, the control system calculates the current fiber film size according to the fiber picture, meanwhile, the current fiber film size is compared with the preset fiber film size, the liquid supply system, the needle switching system and the receiving system are controlled to work according to the comparison result, the visual detection system is adopted to control the switching of needles and the switching of spinning solution, the preparation of multilayer fiber film materials is automatically completed, and the possibility of errors caused by the repositioning problem is reduced.)

1. A near-field direct write apparatus for making a multilayer fibrous film, comprising: the device comprises a high-voltage power supply, a receiving system, a liquid supply system, a control system, a needle head switching system and a visual detection system;

the needle switching system is connected with the liquid supply system through a liquid conveying pipe, the liquid supply system comprises a plurality of liquid storage cavities for storing different spinning solutions or melts, the needle switching system comprises a plurality of needles with different diameters, the anode of the high-voltage power supply is connected with the needles, and the cathode of the high-voltage power supply is connected with a receiving plate of the receiving system;

the control system is respectively electrically connected with the receiving system, the liquid supply system, the high-voltage power supply, the needle head switching system and the visual detection system, the visual detection system is used for shooting a fiber picture on the receiving plate, the control system calculates the current fiber film size according to the fiber picture, meanwhile, the current fiber film size is compared with the preset fiber film size, and when the sizes are equal, the control system controls the liquid supply system to replace spinning solution or melt and controls the needle head switching system to switch needle heads, so that the next layer of spinning fiber film is prepared.

2. The near-field direct writing device for preparing the multilayer fiber film according to claim 1, wherein the visual inspection system further comprises a light source and a display screen, the light source is arranged obliquely above the receiving plate and irradiates the receiving plate, and the display screen is used for displaying the photographed fiber picture.

3. The near-field direct writing apparatus for preparing a multilayer fiber film according to claim 2, wherein the liquid supply system further comprises a syringe pump, a rotary liquid storage cavity selector provided with a plurality of liquid storage cavities;

one end of the liquid storage cavity is provided with a piston, and the other end of the liquid storage cavity is connected with the infusion tube; one end of the injection pump is electrically connected with a control system, when the liquid supply system supplies liquid, the control system controls the injection pump to move, and the injection pump pushes the piston to supply liquid for the needle head.

4. The near-field direct writing device for preparing the multilayer fiber membrane as claimed in claim 3, wherein the needle switching system comprises a fixed chuck provided with a liquid supply pipeline, a needle mounting seat provided with a plurality of needles, a mounting substrate;

the fixed chuck is vertically arranged on the mounting base plate, a rotating main shaft is arranged at the center of the needle head mounting seat, and the rotating main shaft penetrates through the fixed chuck to fix the needle head mounting seat; the upper end of the liquid supply pipeline is connected with the liquid supply system through the liquid conveying pipe, and the lower end of the liquid supply pipeline penetrates through the fixed chuck to be opposite to the upper end of the needle head on the needle head mounting seat.

5. The near-field direct writing device for preparing the multilayer fiber film of claim 4, wherein the lower end of the liquid supply pipeline is of an inverted truncated cone structure, and the upper end of the needle head is of a retractable spring type truncated cone structure;

the retractable spring type cone-shaped structure comprises a spring and a cone-shaped structure connected with one end of the spring, and the other end of the spring is connected with the inner wall of the needle tube of the needle head;

the diameter of the lower interface of the inverted round platform-shaped structure at the lower end of the liquid supply pipeline is larger than that of the upper interface of the spring round platform-shaped structure.

6. The near-field direct-writing device for preparing the multilayer fiber film according to claim 5, wherein a sealing gasket is further arranged on the outer surface of the truncated cone structure of the spring type truncated cone structure.

7. The near-field direct writing apparatus for preparing a multilayer fiber film according to claim 6, wherein the receiving system further comprises a motor, a guide rod connected with the motor and the receiving plate, the motor is electrically connected with the control system, and the control system controls the motor to drive the receiving plate to move along an X axis, a Y axis or a Z axis through the guide rod.

8. A multilayer fiber film production method based on the near-field direct writing apparatus for producing a multilayer fiber film according to any one of claims 1 to 7, comprising the steps of:

shooting a picture of the fiber membrane on the receiving plate;

calculating the fiber membrane picture to obtain the current fiber membrane size;

comparing the current fiber membrane size with a preset fiber membrane size, if the current fiber membrane size is equal to the preset fiber membrane size, turning off a high-voltage power supply, turning off a liquid supply pipeline, and stopping spinning;

replacing spinning solution or melt, switching spinning needle heads and adjusting the distance between a receiving plate and the spinning needle heads;

and starting the high-voltage power supply and the liquid supply pipeline to perform next-layer fiber spinning.

9. The method of claim 8, wherein calculating the fiber film picture to obtain the current fiber film size comprises: performing morphological processing on the fiber membrane picture, wherein the morphological processing comprises gray level transformation, morphological filtering and binaryzation, and calculating according to the fiber membrane picture after the morphological processing to obtain the size of the fiber membrane;

the dimensions of the fiber membrane include thickness, diameter, density.

10. A method of making a multilayer fibrous film according to claim 9 wherein said changing the spinning solution or melt, switching the spinning needle, and adjusting the distance between the receiving plate and the spinning needle comprises:

the control system controls the rotation of the rotary liquid storage cavity selector to enable a liquid storage cavity in which a spinning solution or a melt required for preparing the next layer of film is located to be opposite to the injection pump;

the control system selects a spinning needle head according to the selected spinning solution, controls the rotating main shaft to rotate, rotates the selected spinning needle head to be right below the liquid supply pipeline, and adjusts the distance between the receiving plate and the spinning needle head.

Technical Field

The invention relates to the technical field of electrostatic spinning, in particular to a near-field direct writing device for preparing a multilayer fiber film and a preparation method of the multilayer fiber film.

Background

Electrospinning is a particular fiber manufacturing process in which polymer solutions or melts are jet spun in a strong electric field in such a way as to produce polymer filaments of nanometer diameter. The electrospinning direct writing technology is a novel continuous jet flow jet printing technology based on electrostatic spinning, inhibits the spiral, bending and unstable motion of the traditional electrostatic spinning jet flow, overcomes the defect of disordered deposition of the traditional electrostatic spinning nanofiber, and utilizes the stable linear jet flow to carry out the direct writing preparation of the ordered nanostructure. At present, a fiber membrane consisting of a single material is difficult to meet various requirements in the using process, and the preparation of a multi-layer and multi-material nanofiber membrane is a great trend of electrostatic spinning development. When preparing multilayer, the fibrous membrane of many materials constitution among the prior art, need manual change syringe needle and manual change spinning solution or fuse-element when the different fuse-elements or solution carry out the spinning in the face of, manual change syringe needle and solution can influence electrostatic spinning efficiency and also can increase the possibility that the error appears when manual change syringe needle.

Disclosure of Invention

In order to solve the above problems, the present invention provides a near-field direct writing apparatus for manufacturing a multilayer fiber film, including: the device comprises a high-voltage power supply, a receiving system, a liquid supply system, a control system, a needle head switching system and a visual detection system; the needle switching system is connected with the liquid supply system through a liquid conveying pipe, the liquid supply system comprises a plurality of liquid storage cavities for storing different spinning solutions or melts, the needle switching system comprises a plurality of needles with different diameters, the positive pole of the high-voltage power supply is connected with the needles, and the negative pole of the high-voltage power supply is connected with a receiving plate of the receiving system; the control system is respectively electrically connected with the receiving system, the liquid supply system, the high-voltage power supply, the needle head switching system and the visual detection system, the visual detection system is used for shooting a fiber picture on the receiving plate, the control system calculates according to the fiber picture to obtain the size of a current fiber film, meanwhile, the size of the current fiber film is compared with the size of a preset fiber film, and when the sizes are equal, the control system controls the liquid supply system to replace a spinning solution or melt and controls the needle head switching system to switch a needle head to prepare a next layer of spinning fiber film. Through the arrangement, the automatic control of electrostatic spinning is realized, the efficiency of electrostatic spinning is improved, and meanwhile, the possibility of error is reduced because the spinning solution is replaced and the needle head is switched without manual operation in the spinning process.

Furthermore, the visual inspection system also comprises a light source and a display screen, wherein the light source is arranged above the receiving plate in an inclined mode and irradiates the receiving plate, and the display screen is used for displaying the shot fiber pictures.

Further, the liquid supply system also comprises an injection pump and a rotary liquid storage cavity selector provided with a plurality of liquid storage cavities; one end of the liquid storage cavity is provided with a piston, and the other end of the liquid storage cavity is connected with a liquid conveying pipe; one end of the injection pump is electrically connected with the control system, when the liquid supply system supplies liquid, the control system controls the injection pump to move, and the injection pump pushes the piston to supply liquid for the needle head.

Further, the needle switching system comprises a fixed chuck provided with a liquid supply pipeline, a needle mounting seat provided with a plurality of needles and a mounting substrate; the fixed chuck is vertically arranged on the mounting base plate, the center of the needle mounting seat is provided with a rotating main shaft, and the rotating main shaft penetrates through the fixed chuck to fix the needle mounting seat; the upper end of the liquid supply pipeline is connected with the liquid supply system through a liquid conveying pipe, and the lower end of the liquid supply pipeline penetrates through the fixed chuck to be opposite to the upper end of the needle head on the needle head mounting seat.

Further, the lower end of the liquid supply pipeline is of an inverted round table-shaped structure, and the upper end of the needle head is of a retractable spring type round table-shaped structure; the retractable spring type cone-shaped structure comprises a spring and a cone-shaped structure connected with one end of the spring, and the other end of the spring is connected with the inner wall of the needle tube of the needle head; the diameter of the lower interface of the inverted round platform-shaped structure at the lower end of the liquid supply pipeline is larger than that of the upper interface of the spring round platform-shaped structure.

Furthermore, a sealing washer is arranged on the outer surface of the round platform-shaped structure of the spring type round platform-shaped structure.

Furthermore, the receiving system also comprises a motor and a guide rod connected with the motor and the receiving plate, the motor is electrically connected with the control system, and the control system controls the motor to drive the receiving plate to move along the X axis, the Y axis or the Z axis through the guide rod.

The invention also provides a preparation method of the multilayer fiber film based on the near-field direct writing device for preparing the multilayer fiber film, which is characterized by comprising the following steps of:

shooting a picture of the fiber membrane on the receiving plate;

calculating the fiber membrane picture to obtain the current fiber membrane size;

comparing the current fiber membrane size with a preset fiber membrane size, if the current fiber membrane size is equal to the preset fiber membrane size, turning off a high-voltage power supply, turning off a liquid supply pipeline, and stopping spinning;

replacing a spinning solution, switching a spinning needle head and adjusting the distance between a receiving plate and the spinning needle head; and starting the high-voltage power supply and the liquid supply pipeline to perform next-layer fiber spinning.

Further, calculating the fiber membrane picture to obtain the current fiber membrane size includes: and performing morphological processing on the fiber membrane picture, wherein the morphological processing comprises gray level transformation, morphological filtering and binaryzation, and calculating according to the fiber membrane picture after the morphological processing to obtain the size of the fiber membrane, and the size of the fiber membrane comprises thickness, diameter and density.

Further, changing the spinning solution or the melt, switching the spinning needle head, and adjusting the distance between the receiving plate and the spinning needle head include: the control system controls the rotation of the rotary liquid storage cavity selector to enable a liquid storage cavity in which a spinning solution or a melt required for preparing the next layer of film is located to be opposite to the injection pump; the control system selects a spinning needle head according to the selected spinning solution, controls the rotating main shaft to rotate, rotates the selected spinning needle head to be right below the liquid supply pipeline, and adjusts the distance between the receiving plate and the spinning needle head.

The near-field direct-writing device for preparing the multilayer fiber film and the preparation method of the multilayer fiber film, provided by the invention, realize automatic electrostatic spinning, have higher automation degree, improve the working efficiency of electrostatic spinning, reduce spinning errors to a certain extent and improve the quality of electrostatic spinning.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a functional block diagram according to an embodiment of the present invention;

FIG. 2 is a block diagram of an apparatus according to an embodiment of the present invention;

FIG. 3 is a top view of a rotary reservoir selector in one embodiment of the present invention;

FIG. 4 is a front view of a rotary reservoir selector in one embodiment of the present invention;

FIG. 5 is a block diagram of a needle switching system in accordance with one embodiment of the present invention;

FIG. 6 is an enlarged view of a portion of the liquid supply conduit and the needle in an embodiment of the present invention;

FIG. 7 is a flow chart illustrating the automated production of a multilayer fibrous membrane in accordance with one embodiment of the present invention;

FIG. 8 is a closed-loop control diagram for producing a multilayer fibrous membrane according to one embodiment of the present invention;

the device comprises a control system 1, a high-voltage power supply 2, a receiving system 3, a liquid supply system 4, a needle switching system 5, a visual detection system 6, an injection pump 41, a rotating shaft 42, a liquid storage cavity 43, a piston 44, a fixed chuck 51, a needle mounting seat 52, a mounting base plate 53, a liquid supply pipeline 54, a needle 55, a rotating spindle 56 and a sealing gasket 5501.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In one embodiment of the present invention, as shown in fig. 1-2, the present invention provides a near-field direct write apparatus for preparing a multilayer fiber film, comprising: the device comprises a control system 1, a high-voltage power supply 2, a receiving system 3, a liquid supply system 4, a needle head switching system 5 and a visual detection system 6, wherein the needle head switching system 5 is connected with the liquid supply system 4 through a liquid conveying pipe, the liquid supply system 4 comprises a plurality of liquid storage cavities 43 for storing different spinning solutions, the needle head switching system 5 comprises a plurality of needle heads 55 with different diameters, when electrostatic spinning is carried out, the positive pole of the high-voltage power supply 2 is connected with one of the needle heads 55, the negative pole of the high-voltage power supply 2 is connected with a receiving plate of the receiving system 3, when the high-voltage power supply 2 is started, proper voltage is adjusted to enable the polymerized spinning solution or melt to form continuous jet flow under the action of high voltage, the jet flow is stretched, a solvent. In this embodiment, the control system 1 is electrically connected to the receiving system 3, the liquid supply system 4, the high voltage power supply 2, the needle switching system 5 and the vision detection system 6, specifically, the vision detection system 6 includes a camera assembly, the camera assembly shoots a fiber picture on the receiving board through a micro lens installed on the camera assembly, and transmits the shot fiber picture to the control system 1, the control system 1 calculates the size of the fiber film on the current receiving board according to the fiber picture, meanwhile, compares the size of the fiber film on the current receiving board with the preset size of the fiber film, when the sizes are equal, stops spinning, the control system 1 controls the liquid supply system 4 to replace a spinning solution or melt, the needle switching system 5 switches needles to start spinning of the next layer of fiber film, thereby realizing automatic control of the near-field direct writing device for preparing multilayer fiber films, when multilayer fiber membranes made of different materials are prepared, the near-field direct writing device for preparing the multilayer fiber membranes can realize automatic replacement of spinning solution and automatic switching of needles adaptive to the spinning solution, so that the electrostatic spinning efficiency is improved, errors can be reduced by replacing manual replacement of the needles with automatic control, and the needles can be displaced and positioned inaccurately when the needles are replaced manually, so that spinning errors are generated. Specifically, if the size of the fiber membrane on the current receiving plate is equal to the preset size of the fiber membrane, the control system 1 closes the high-voltage power supply 2, so that the near-field direct writing device for preparing the multilayer fiber membrane stops spinning, and simultaneously, the control system 1 controls the liquid supply system 4 to select and replace the spinning solution or melt required for preparing the next layer of fiber membrane according to a preset program, controls the needle switching system 5 to switch the needle corresponding to the spinning solution, and starts the high-voltage power supply 2 to adjust to a proper voltage to start the next layer of spinning. The specific process of automatically controlling, selecting and replacing the spinning solution or melt and automatically switching the needle is described in detail below, and will not be described in detail herein.

Optionally, the visual detection system 6 further includes a light source, the light source is disposed above the receiving plate in an oblique direction, and the light source irradiates the receiving plate to provide a sufficient light source for the visual detection system 6 to shoot the fiber picture on the receiving plate, so that the fiber picture shot by the camera assembly of the visual detection system 6 is clearer, and a more accurate basis is provided for the automatic control of the subsequent control system.

Optionally, the visual inspection system 6 further includes a display screen, the fiber picture shot by the visual inspection system 6 is displayed on the display screen in real time, and an operator can judge the spinning process through the display screen at any time, so that the near-field direct writing device for preparing the multilayer fiber film can be manually controlled to spin.

In another embodiment of the present invention, the liquid supply system 4 further comprises an injection pump 41, a liquid storage cavity selector having a plurality of liquid storage cavities 43, as shown in fig. 3, which is a top view of the liquid storage cavity selector, fig. 4 is a front view of the liquid storage cavity selector, the liquid storage cavity selector has a rotating shaft 42 disposed at a central position of the liquid storage cavity selector, and a plurality of liquid storage cavities 43, the rotating shaft 42 is driven by a motor for rotating the liquid storage cavity selector to rotate the liquid storage cavities 43 storing the spinning solution required for electrospinning right under the injection pump 41, the position of the injection pump 41 is fixed, when electrospinning, one of the liquid storage cavities 43 on the liquid storage cavity selector needs to be positioned right under the injection pump 41, one end of the injection pump 41 is electrically connected to the control system 1, when the electrospinning liquid supply system 4 needs to supply the polymer solution or the melt to the needle 55 for spinning, the control system 1 controls the syringe pump 41 to move towards a liquid storage cavity 43 right below the syringe pump 41, specifically, a piston 44 is further disposed at one end of the liquid storage cavity 43 opposite to the syringe pump 41, and when the syringe pump 41 pushes the piston 44 of the liquid storage cavity 43 to move, the spinning melt or solution inside the liquid storage cavity 43 is output from the other end of the liquid storage cavity 43 and enters the needle 55 through a liquid conveying pipe (in fig. 1, the syringe pump 41 and the liquid storage cavity selector in the liquid supply system 4 are both horizontally disposed). In this embodiment, 3 liquid storage cavities 43 are taken as an example for explanation, the 3 liquid storage cavities 43 are uniformly arranged, the center of each liquid storage cavity 43 is connected with the center of the rotating shaft, and an included angle between adjacent connecting lines is 120 degrees, so that the liquid storage cavity 43 storing the currently required spinning solution or melt is positioned under the injection pump 41 only when spinning is started, and then the rotating shaft is only required to be driven to rotate 120 degrees when the spinning solution rotating liquid storage cavity 43 is replaced, and the positioning is not required again, so that the working procedure in the process of preparing the multilayer fiber films made of different materials is simplified, and the spinning efficiency is improved. It should be understood that 3 liquid storage cavities are provided on the liquid storage cavity selector in this embodiment, which is only an example, and other numbers of liquid storage cavities may be provided according to needs, and if the number of liquid storage cavities changes, the degree of rotation required when the liquid storage cavities are rotated also changes accordingly, and the specific control should be set according to actual conditions.

In a further embodiment of the present invention, as shown in fig. 5, the needle switching system 5 comprises a fixed chuck 51 provided with a liquid supply pipe 54, a needle mount 52 mounted with a plurality of needles 55, a mounting base plate 53. Specifically, the plurality of needles 55 are uniformly arranged on the circumference of a circle having a center of the needle mounting seat 52 as a circular point and a certain length L as a radius, and the value of L is set according to the actual situation, and is not limited herein. The fixed chuck 51 is vertically arranged on the mounting base plate, the center of the needle mounting seat 52 is provided with a rotating spindle 56, and the rotating spindle 56 penetrates through the fixed chuck 51 to fix the needle mounting seat 52; the upper end of the liquid supply pipeline 54 is connected with the liquid supply system 4 through a liquid conveying pipe, and the lower end of the liquid supply pipeline 54 passes through the fixed chuck 51 and is opposite to the upper end of the needle 55 on the needle mounting seat 52. In this embodiment, the rotating spindle 56 is connected to the fixed chuck 51 by a rolling bearing, the rotating spindle 56 is driven to rotate by a motor controlled by the control system 1, the fixed chuck 51 and the liquid supply pipe 54 on the fixed chuck 51 are fixed when the rotating spindle 56 rotates, and only the needle mounting seat 52 rotates along with the rotating spindle 56, so as to change the needle 55 connected to the liquid supply pipe 54. Through the above-mentioned setting, when carrying out electrostatic spinning, fix a position syringe needle 55, as long as guarantee syringe needle 55 upper end and supply liquid pipe 54's lower extreme on vertical direction on a straight line can, the positioning process is simple, there is not the error, carry out many materials afterwards, carry out the secondary location to syringe needle 55 when needing to be changed the syringe needle when multilayer fibre membrane spinning, only need make the rotatory predetermined angle of rotating spindle can, to spinning the syringe needle is equipped with 3 for example, then need control rotating spindle 56 rotatory 120 when changing the syringe needle, thereby can simplify many materials, the procedure of multilayer fibre membrane spinning, it is littleer to compare in the manual work change syringe needle error, efficiency is higher.

Further, in another embodiment of the present invention, as shown in fig. 6, in order to achieve a good seal between the needle 55 and the liquid supply pipe 54 when electrospinning is performed, the liquid supply pipe 54 is disposed at an end close to the needle 55, i.e., a lower end of the liquid supply pipe 54, in an inverted truncated cone structure, and the needle 55 is disposed at an end close to the liquid supply pipe 54, i.e., an upper end of the needle 55, in a retractable spring type truncated cone structure, wherein the retractable spring type truncated cone structure comprises a spring connected to an inner wall of the needle pipe and a truncated cone structure connected to the spring. When the side surface of the spring type round platform-shaped structure of the needle head is contacted with the side surface of the inverted round platform-shaped structure of the liquid supply pipeline when the needle head is switched, the liquid supply pipeline can apply a force to the spring type round platform-shaped structure, so that the spring is compressed, the spring type round platform-shaped structure moves downwards and retracts into the needle tube of the needle head until the needle head rotates to the position right below the liquid supply pipeline, the spring expands, the spring type round platform-shaped structure of the needle head 55 pops out to enter the round platform-shaped structure of the liquid supply pipeline, it should be noted that the diameter of the lower interface of the inverted round platform-shaped structure at the lower end of the liquid supply pipeline 54 is larger than that of the upper interface of the spring type round platform-shaped structure, so that the spring type round platform-shaped structure can pop out smoothly to enter the round platform-shaped structure.

Optionally, as shown in another embodiment of the present invention, a sealing gasket is disposed on an outer surface of the truncated cone structure of the spring-type truncated cone structure, so that when the spring-type truncated cone structure is located in the liquid supply pipe, further sealing can be performed to prevent liquid leakage.

In another embodiment of the present invention, the receiving system 3 comprises a motor and a guide rod, one end of the motor is electrically connected to the control system 1, the other end of the motor is connected to the receiving plate through the guide rod, in the near-field spinning, the stable distances of different solutions or solutions in an electric field are different, so that if the distance between the receiving plate and a needle is not adjusted accordingly when different spinning solutions or solutions are used for electrostatic spinning, the electrostatic spinning will generate whip phenomenon, and to avoid whip phenomenon, controllable near-field spinning is realized, the receiving distance must be matched with the size of the spinning solution and the electric field, in this embodiment, the receiving system 3 further comprises a motor and a guide rod, the motor drives the receiving plate to move in the X-axis, Y-axis or Z-axis direction according to the driving guide rod of the control system 1, the receiving plate moves in the X-axis and Y-axis during the electrostatic spinning to receive the fibers ejected from the needle, and, when changing spinning solution and switching the syringe needle, thereby control system 1 can drive the distance between adjusting receiving plate and the syringe needle along the motion of Z axle direction according to the kind control motor drive guide arm of spinning solution to realize the automatic distance between regulation and control receiving plate and the syringe needle, avoid appearing whip phenomenon, improve electrostatic spinning quality.

The invention also provides a preparation method of the multilayer fiber film, which is based on the near-field direct writing device for preparing the multilayer fiber film, and specifically as shown in fig. 7, the preparation method of the multilayer fiber film comprises the following steps:

s601, shooting a fiber membrane picture on a receiving plate;

s602: calculating the fiber membrane picture to obtain the current fiber membrane size;

s603: comparing the current fiber membrane size with a preset fiber membrane size, if the sizes are equal, executing a step S604, otherwise executing a step S601;

s604: turning off the high-voltage power supply and the liquid supply pipeline, and stopping spinning;

s605: replacing a spinning solution, switching a spinning needle head and adjusting the distance between a receiving plate and the spinning needle head;

s606: and starting the high-voltage power supply and the liquid supply pipeline, starting spinning the next layer of fiber film, and returning to the step S601.

Through the above steps, the control system 1 realizes automatic control of electrostatic spinning, does not need manual operation, improves spinning efficiency, and simultaneously, because the needle 55 only needs to be positioned once, only the rotating main shaft 56 needs to be rotated by a certain angle (the angle can be changed according to the position of the needle and the number of the needles) when next layer of spinning is carried out, the secondary positioning is not needed, and the error is reduced while the efficiency is improved. As shown in fig. 8, a recyclable closed-loop control is formed in the automatic preparation process of the multilayer fiber film, and the visual inspection system 6 continuously takes fiber pictures and sends the pictures to the control system 1 for calculation and judgment of the spinning process, so that the liquid supply system 4, the needle switching system 5 and the receiving system 3 are controlled to work to realize the automatic preparation of the multilayer fiber film.

In an embodiment, the calculating, by the control system 1, the current fiber membrane size from the fiber membrane picture includes: the method comprises the steps of performing morphological processing on a fiber membrane picture, wherein the morphological processing comprises gray level transformation, morphological filtering and binarization, calculating according to the fiber membrane picture after the morphological processing to obtain the size of the fiber membrane, further, the size of the fiber membrane comprises thickness, diameter and density, and certainly, other size parameters of the fiber membrane can be used as the basis for automatic control, the size of the fiber membrane can be adjusted automatically according to actual needs, the calculation of the size of the fiber membrane can be realized by adopting the existing calculation method, and redundant description is not repeated.

In one embodiment, the control system 1 controlling the changing of the spinning solution or melt, the switching of the spinning needle, and the adjusting of the distance between the receiving plate and the spinning needle comprises: the control system 1 controls the liquid storage cavity selector to rotate, and a liquid storage cavity 43 where a spinning solution required for preparing the next layer of film is located is opposite to the injection pump 41;

the control system 1 selects one needle 55 according to the selected spinning solution, controls the rotating main shaft 56 to rotate, rotates the selected needle 55 to be right below the liquid supply pipeline 54, and adjusts the distance between the receiving plate and the needle 55. Because the diameters of the needles 55 used by different spinning solutions are different, and the requirements on the distance between the receiving plate and the needle 55 are also different, the spinning solutions are replaced, and the distances between the needle 55 and the receiving plate and the needle 55 need to be changed along with the replacement, so that the spinning quality is ensured.

The terms and expressions used in the specification of the present invention have been set forth for illustrative purposes only and are not meant to be limiting. It will be appreciated by those skilled in the art that changes could be made to the details of the above-described embodiments without departing from the underlying principles thereof. The scope of the invention is, therefore, indicated by the appended claims, in which all terms are intended to be interpreted in their broadest reasonable sense unless otherwise indicated.