CN106733393A - Double dislocation coating method and devices - Google Patents

Abstract

The present application relates to the field of energy storage devices, and in particular to a double dislocation coating method and device. Lay the cloth surface with the lip die head; use the kiss coating method to coat the surface to be coated; after coating to a predetermined length, change the distance between the base material and the lip die head so that the surface to be coated and the lip die head head off. The device includes a first roller, a second roller, a moving assembly and a kiss coating assembly; the kiss coating assembly includes a staggered lip die head, and the staggered lip die head is located between the first roll and the second roll in the conveying direction, and faces to the Cloth surface; the moving assembly is connected to at least one of the first roll, the second roll, and the kiss coating assembly, and can drive the first roll, the second roll or the staggered lip die head to move to change the relationship between the base material and the staggered lip die head distance, and attach/disengage the surface to be coated with the lip die. The double dislocation coating method and device provided in the present application can ensure uniform coating weight.

Description

Double dislocation coating method and device

technical field

The present application relates to the field of coating processing, in particular to a double dislocation coating method and device.

Background technique

In related technologies, lithium batteries are generally coated by extrusion coating, which can be specifically divided into single dislocation coating and double dislocation coating.

Compared with single dislocation coating, double dislocation coating can significantly increase energy density and reduce material waste. However, in the double dislocation coating process, one side of the substrate must be dislocated first to form a single side area and a blank area, and when coating the other side of the substrate, the back roller will alternate with the coating area and the blank area Cooperate, and there will be a significant height difference when transitioning from the single-sided area to the blank area, resulting in a huge drop in the blank area during double-sided coating, which will affect the coating weight and cause uneven coating weight.

The uneven coating weight is likely to cause the risk of lithium deposition, and during the cycle cycle, due to the uneven current density distribution, the local position of the battery cell will overheat, and the isolation film is easy to shrink and deform at high temperature, which will cause the battery cell to short-circuit and catch fire. pose a security risk.

Contents of the invention

The present application provides a double dislocation coating method and device, which can solve the above problems.

The first aspect of the embodiment of the present application provides a double dislocation coating method. The two sides of the substrate coated by this method are respectively the coated surface and the surface to be coated, including the following steps:

(a), after the substrate is tensioned and conveyed to the coating position, the distance between the substrate and the split-lip die is changed, so that the surface to be coated is attached to the split-lip die, And the said coated surface corresponding to said wrong-lip die head is in unsupported state;

(b), adopting the kiss coating method to coat the surface to be coated;

(c) After coating to a predetermined length, change the distance between the base material and the split-lip die to separate the surface to be coated from the split-lip die, thereby stopping the coating.

Preferably, in the step (a) and the step (c), the method of changing the distance between the base material and the lip-staggered die is specifically: changing the conveying trajectory of the base material.

Preferably, in the step (a) and/or the step (c), the transport trajectory of the substrate is changed in a rotational or translational manner.

Preferably, in the step (a), the tension of the substrate is 40-80N.

Preferably, the tension conveying direction of the substrate is from bottom to top.

Preferably, in the step (b), the coating pressure of the kiss coating method is 10-40KPa.

The second aspect of the embodiment of the present application provides a double dislocation coating device. The two sides of the substrate coated by the device are the coated surface and the surface to be coated respectively. The double dislocation coating device includes a first rolls, second rolls, moving components and kiss coating components;

The first roller and the second roller are arranged in parallel at intervals, and the first roller and the second roller can cooperate with the substrate in sequence in the conveying direction of the substrate, so that the The substrate can be tensioned and conveyed between the two;

The kiss coating assembly includes a split-lip die head, and the split-lip die head is located between the first roller and the second roller in the conveying direction, and faces the surface to be coated;

The moving assembly is connected to at least one of the first roller, the second roller, and the kiss coating assembly, and can drive the first roller, the second roller, or the kiss coating assembly connected to it. The split-lip die in the assembly moves to change the distance between the base material and the split-lip die, and attaches/disengages the surface to be coated with the split-lip die.

Preferably, the first roller is located below the second roller.

Preferably, the moving assembly is connected to the first roller or the second roller, and can drive the first roller or the second roller connected to it to move, so that the conveying track of the substrate is not The second roller or the first roller connected to the moving assembly rotates as an axis, and attaches/disengages the surface to be coated with the split-lip die head.

Preferably, the moving assembly is connected to the first roller and the second roller at the same time, and can drive the first roller and the second roller to move at the same time, so that the conveying track of the substrate is close to Or translation occurs in a direction away from the lip-stitching die, and the surface to be coated is attached to/disengaged from the lip-staggering die.

Preferably, the staggered lip die includes a lower lip of the die and an upper lip of the die,

The lower lip of the die head and the upper lip of the die head are sequentially arranged in the conveying direction, the lower lip of the die head and the upper lip of the die head form a staggered lip structure, and the upper lip of the die head is lower than the lower lip of the die head The lip is far away from the substrate, and the misalignment range between the upper lip of the die and the lower lip of the die is 50-500 μm.

The technical solutions provided in the embodiments of the present application can achieve the following beneficial effects:

The double dislocation coating method and device provided in the embodiment of the present application use the moving component to drive the movement of the first roller or the second roller to change the conveying track of the substrate, and then control the cooperation relationship between the substrate and the dislocation lip die head, to control the coating process. Since the wrong-lip die is always attached to the surface to be coated during the coating process, the coating thickness and coating weight are uniform without large deviations, effectively reducing the risk of lithium deposition.

It is to be understood that both the foregoing general description and the following detailed description are exemplary only and are not restrictive of the application.

Description of drawings

Fig. 1 is a schematic view of the use state of a double dislocation coating device provided by the embodiment of the present application.

Reference signs:

1 - Substrate;

10 - coated surface;

12 - the surface to be coated;

2- Double dislocation coating device;

20 - the first roll;

22 - the second roller;

24 - mobile components;

26 - Kiss coating components;

260-wrong lip die head;

260a-die lower lip;

260b-die upper lip;

262-feeding unit;

28 - Sensor.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description serve to explain the principles of the application.

detailed description

The present application will be described in further detail below through specific embodiments and in conjunction with the accompanying drawings. The "front", "rear", "left", "right", "upper" and "lower" mentioned in the text are all referred to the double dislocation coating device in the accompanying drawings.

The embodiment of the present application provides a double dislocation coating device 2. As shown in FIG. The coating surface 10 has been coated with a coating layer at intervals in the previous process, forming a single-sided area and a blank area.

Please continue to refer to FIG. 1 , the double dislocation coating device 2 includes a first roll 20 , a second roll 22 , a moving assembly 24 and a kiss coating assembly 26 .

The first roller 20 and the second roller 22 are arranged in parallel and at intervals, and generally the rotation axes of the first roller 20 and the second roller 22 are parallel to the horizontal plane. The substrate 1 cooperates with the first roller 20 and the second roller 22 sequentially in the conveying direction (directed by the arrow in the figure), so that the substrate 1 can be conveyed under tension between the two. Specifically, the substrate 1 can be attached to the roller surfaces of the first roller 20 and the second roller 22 in sequence, and the force between the roller surface and the substrate 1 can be used to realize the turning and tensioning of the substrate 1 during the conveying process.

Usually, when the substrate 1 is transported, the coated surface 10 will face the first roller 20 and the second roller 22, and the single-sided area and the coating area will be attached to the first roller 20 and the second roller 22. The conveying path of the material 1 is rotated by 90 degrees at the first roller 20 and the second roller 22, forming a similar C-shaped structure (see FIG. 1 ). This structure can display the surface to be coated 12 to a large extent, so as to facilitate the setting of the negative pressure component 24 and kiss coating component 26 . However, in extreme cases, it is not ruled out that the substrate 1 will turn the surface to be coated 12 toward one of the first roller 20 or the second roller 22 to form an S-shaped conveying track.

The double dislocation coating device 2 provided in this embodiment does not use a press coating assembly, but uses a kiss coating assembly 26 instead. As shown in Figure 1, the kiss coating assembly 26 includes a wrong lip die head 260, in addition, it can also include a feeding unit 262 for feeding the wrong lip die head 260, etc., the wrong lip die head 260 is located at the conveying direction Between the first roller 20 and the second roller 22 , and facing the surface to be coated 12 .

The moving assembly 24 is connected to at least one of the first roller 20 , the second roller 22 , and the kiss coating assembly 26 . When the moving component 24 is connected with the kiss coating component 26, the moving component 24 can drive the kiss coating component 26 to move as a whole, or only drive the lip die 260 to move, but no matter how it is connected, it needs to be able to drive the lip die 260 to move . By moving the lip-stitching die 260 , the distance between the lip-staggering die 260 and the substrate 1 can be changed.

When the moving assembly 24 is connected with the first roller 20 or the second roller 22, it includes two situations, that is to say, the moving assembly 24 can only be connected with the first roller 20 or the second roller 22, or can be connected with the first roller 22 at the same time. The roller 20 and the second roller 22 are connected. These two cases are described below.

For the first case, the moving assembly 24 is only connected to the first roller 20 or the second roller 22 . At this time, the moving assembly 24 can only drive the first roller 20 or the second roller 22, and the moving assembly 24 is only connected to the first roller 20 as an example, that is to say, the first roller 20 can be driven by the moving assembly 24 to generate Displacement, while the position of the second roller 22 that is not connected with the moving assembly 24 is always in a fixed state. When the moving assembly 24 drives the first roller 20 to move, it needs to be able to make the conveying path of the substrate 1 rotate around the second roller 22 . In order to meet this requirement, the moving direction of the first roller 20 should be along the thickness direction of the substrate 1, which is also the radial direction of the first roller 20, and the moving direction should not be in line with the tension conveying direction of the substrate 1. parallel. Since the split lip die head 260 is located between the first roll 20 and the second roll 22, when the conveying path of the substrate 1 is rotated with the second roll 22 as the axis, the surface to be coated 12 and the split lip die head can be changed. 260 spacing. Connecting the moving assembly 24 to the second roller 22 produces the same effect, but in the opposite direction of rotation.

For the second case, the moving assembly 24 is connected to the first roller 20 and the second roller 22 at the same time, and at this time, both the first roller 20 and the second roller 22 can move. In this case, the movement of the first roller 20 and the second roller 22 can be simultaneously controlled by the moving assembly 24. Since the substrate 1 cooperates with the first roller 20 and the second roller 22 in sequence, the first roller 20 and the second roller Simultaneous movement of the two rollers 22 will result in displacement of the conveying track of the substrate 1 . Utilizing this point, the movement of the first roller 20 and the second roller 22 can make the conveying path of the substrate 1 move in translation in the direction of approaching or moving away from the lip-staggered die head 260 .

The coating process of the wrong-lip die 260 needs to be in close contact with the surface 12 to be coated. For example, as shown in Figure 1, in this embodiment, the wrong-lip die 260 includes the lower lip 260a of the die and the upper lip of the die. 260b, the die head lower lip 260a and the die head upper lip 260b are arranged sequentially in the conveying direction, the die head lower lip 260a and the die head upper lip 260b form a staggered lip structure, wherein the die head upper lip 260b is farther away from the base than the die head lower lip 260a Material 1. When coating, the surface 12 to be coated needs to be attached to the lower lip 260a of the die head. Since the upper lip 260b of the die head and the lower lip 260a of the die head will be staggered by a certain position, the coating can release the pressure and form a wetting at the staggered position. Angle, along with the conveyance of substrate 1, coating just is coated on the surface 12 to be coated continuously. In this embodiment, the misalignment range between the upper die lip 260b and the lower die lip 260a is preferably 50-500 μm, which can form a better wetting angle. And in the non-coating state, it needs to be in a disengagement state between the staggered lip die head 260 and the surface 12 to be coated of the substrate 1, and there is a certain gap between the two, so that the conveying process of the substrate 1 will not stop at this moment. It will accompany the coating process, so as to realize the interruption of coating.

Therefore, the main purpose of changing the transport trajectory of the substrate 1 is to control the coating process. Drive the first roller 20 or the second roller 22 to move by the moving assembly 24, can change the conveying track of the substrate 1, make the substrate 1 can be with the mold that will be coated with the surface 12 and the lip die head 260 when it needs to be coated. The lower lip 260a of the die is bonded, and the conveying track of the substrate 1 can be changed when coating is not required, so that the surface to be coated 12 is separated from the lower lip 260a of the die.

In order to achieve stable movement, cylinders, servo motors, stepping motors, etc. can be used as the power source of the moving assembly 24, for example, a screw is screwed to the first roller 20 or the second roller 22, and the screw is driven by the servo motor Rotate, and convert the rotation into linear motion through screw connection, and finally drive the first roller 20 or the second roller 22 to move. When the moving assembly 24 is connected to the first roller 20 and the second roller 22 at the same time, two sets of servo motors and screw rods can be provided separately, or the first roller 20 and the second roller 22 can be connected through a connecting piece and driven in a unified manner. .

In this embodiment, in order to improve the uniformity of coating, it is preferable to position the first roller 20 below the second roller 22, so that the conveying path of the substrate 1 will be between the first roller 20 and the second roller 22. Keep feeding upwards. When coating, the lower lip 260a of the die is in contact with the surface 12 to be coated, and the paint is coated onto the surface 12 to be coated as the substrate 1 is conveyed upwards, and the wetting angle during the coating process can avoid Spreads downward under the influence of gravity to better maintain coating uniformity.

This embodiment provides a double dislocation coating method, which specifically includes the following steps:

S10. After the base material is tensioned and conveyed to the coating position, change the distance between the base material and the split-lip die head, so that the surface to be coated is attached to the split-lip die head, and the gap corresponding to the split-lip die head is The coated surface is in an unsupported state;

S20. Coating the surface to be coated by kiss coating;

S30. After coating to a predetermined length, change the distance between the substrate and the split-lip die to separate the surface to be coated from the split-lip die, thereby stopping the coating.

This method can be implemented by the double dislocation coating device 2 provided in this embodiment, and the double dislocation coating method and the double dislocation coating device 2 will be described below.

In the above method, S10 is mainly realized by the first roller 20, the second roller 22, the kiss coating assembly 26 and the moving assembly 24. The first roller 20 and the second roller 22 are responsible for realizing the tension conveying of the substrate 1, and the tension generally requires Reach 40 ~ 80N. It should be noted that the first roller 20 and the second roller 22 may only be used to maintain the tension, and the adjustment of the tension does not necessarily require the first roller 20 and the second roller 22 to be realized. For example, the substrate 1 may be passed through another Tension adjustment components to achieve tension adjustment.

There are many ways to judge whether the substrate 1 has been transported to the coating position. A specific mark is set at an appropriate position on the substrate 1, and then the substrate 1 is continuously monitored by sensors 28 such as infrared and photoelectric. When there is a specific mark on the substrate 1, it can be judged that it has been transported to the coating position. The identification process can be carried out by PLC.

When a specific mark is identified, the PLC generates a control signal to control the movement assembly 24 to start and drive the first roller 20 , the second roller 22 or the kiss coating assembly 26 to move. Taking the moving assembly 24 to drive the first roller 20 or the second roller 22 to move as an example, the movement of the first roller 20 or the second roller 22 will cause the change of the conveying track of the substrate 1, and the moving target position is the The surface 12 can be attached to the lip die 260 .

At this time, since the lip die head 260 is between the first roll 20 and the second roll 22, the coated surface 10 on the substrate 1 opposite to the lip die head 260 is completely exposed without any support. The distance between the coating surface 12 and the split-lip die 260 can be controlled by the positions of the first roll 20 and the second roll 22 .

It should be noted that since the substrate 1 is in contact with the roller surface with a single-sided area and a blank area when passing through the first roller 20 and the second roller 22, there is a height difference between the single-sided area and the blank area, so It is inevitable that slight changes such as shaking will occur in the conveying track of the substrate 1. Therefore, in order to ensure a continuous and stable bonding relationship between the surface to be coated 12 and the lip die 260, the surface to be coated 12 and the lip It is better to maintain a certain pressing force between the die heads 260, and even make the lip-staggered die head 260 press the substrate 1 to form a slight turning point in the conveying track.

After the lip-stitching die head 260 is attached to the surface 12 to be coated, S30 starts. In this step, the coating pressure is preferably kept within the range of 10-40KPa. At this time, the coating length can be calculated synchronously through an encoder or other means, and of course it does not exclude the use of other means to control the coating length.

When the coating length reaches the requirement, the PLC sends a control signal again to control the moving assembly 24 to move in reverse, so that the lip-stitching die 260 is out of contact with the surface to be coated 12, and the coating process is completed.

In the coating process, no matter whether the coated surface 10 is a single-sided area or a blank area, the surface to be coated 12 and the lower lip 260a of the lip-staggered die 260 are always attached together, and the distance between the two is basically the same. Therefore, it can ensure that the coating thickness and coating weight are uniform, and there will be no large deviation, which can effectively reduce the risk of lithium analysis.

The present application further illustrates the technical effect through experimental data. The methods and equipment used in the experimental examples and comparative examples of the present application are the double dislocation coating methods and devices provided in the embodiments of the present application, wherein the coating pressure, dislocation lip Value, base tension, measurement results and conclusions are shown in Table 1. In the experimental example and the comparative example, the coating weight is required to be 0.32g.

Table 1 Relevant parameters and conclusions of the experimental example and comparative example of the double dislocation coating method

It can be seen from Table 1 that if the coating pressure is too large, the tension is too large or too small, and the lip is too large or too small, the coating effect will be affected. When the coating pressure is 10-40KPa and the tension is 40-80N , When the misaligned lip is in the range of 50-500μm, the best coating effect can be achieved, and the coating weight is the most accurate and uniform.

The double dislocation coating method and device provided in the embodiment of the present application can ensure that the coating thickness and coating weight are uniform without large deviations, and effectively reduce the risk of lithium analysis.

The above is only a preferred embodiment of the application, and is not intended to limit the application. For those skilled in the art, the application can have various modifications and changes, based on any amendments, equivalent replacements, Improvements, etc., should all be included within the protection scope of the present application.

Claims (11)

1. A double dislocation coating method, the base material two sides that adopt this method to coat are respectively coated surface and to-be-coated surface, it is characterized in that, comprises the following steps: (a), after the substrate is tensioned and conveyed to the coating position, the distance between the substrate and the split-lip die is changed, so that the surface to be coated is attached to the split-lip die, And the said coated surface corresponding to said wrong-lip die head is in unsupported state; (b), adopting the kiss coating method to coat the surface to be coated; (c) After coating to a predetermined length, change the distance between the base material and the split-lip die to separate the surface to be coated from the split-lip die, thereby stopping the coating. 2. double dislocation coating method as claimed in claim 1, is characterized in that, In the step (a) and the step (c), the method of changing the distance between the base material and the lip-staggered die is specifically: changing the conveying track of the base material. 3 . The double dislocation coating method according to claim 2 , characterized in that, in the step (a) and/or the step (c), the conveying trajectory of the substrate is changed by rotation or translation. 4 . 4. The double dislocation coating method according to any one of claims 1 to 3, characterized in that, in the step (a), the tension of the substrate is 40-80N. 5. The double dislocation coating method according to any one of claims 1 to 3, characterized in that, in the step (a), the tension conveying direction of the substrate is from bottom to top. 6. The double dislocation coating method according to any one of claims 1 to 3, characterized in that, in the step (b), the coating pressure of the kiss coating method is 10-40KPa. 7. A double dislocation coating device, the two sides of the substrate coated by the device are respectively the coated surface and the surface to be coated, it is characterized in that the double dislocation coating device includes a first roller, a second rollers, moving components and kiss coating components; The first roller and the second roller are arranged in parallel at intervals, and the first roller and the second roller can cooperate with the substrate in sequence in the conveying direction of the substrate, so that the The substrate can be tensioned and conveyed between the two; The kiss coating assembly includes a split-lip die head, and the split-lip die head is located between the first roller and the second roller in the conveying direction, and faces the surface to be coated; The moving assembly is connected to at least one of the first roller, the second roller, and the kiss coating assembly, and can drive the first roller, the second roller, or the kiss coating assembly connected to it. The split-lip die head of the assembly moves to change the distance between the substrate and the split-lip die head, and attaches/disengages the surface to be coated with the split-lip die head. 8. The double dislocation coating device according to claim 7, wherein the first roller is located below the second roller. 9. The double dislocation coating device according to claim 7, wherein the moving assembly is connected to the first roller or the second roller, and can drive the first roller or the second roller connected to it The second roller moves, so that the conveying path of the base material is rotated around the second roller or the first roller that is not connected with the moving assembly, and the surface to be coated is connected to the lip die head Fit/detach. 10. The double dislocation coating device according to claim 7, wherein the moving assembly is connected to the first roller and the second roller at the same time, and can drive the first roller and the second roller The two rollers move at the same time, so that the conveying path of the substrate is translated in a direction approaching or away from the split-lip die head, and the surface to be coated is attached to/disengaged from the split-lip die head. 11. The double dislocation coating device as claimed in claim 7, wherein the dislocation die includes a lower lip of the die and an upper lip of the die, The lower lip of the die head and the upper lip of the die head are sequentially arranged in the conveying direction, the lower lip of the die head and the upper lip of the die head form a staggered lip structure, and the upper lip of the die head is lower than the lower lip of the die head The lip is far away from the substrate, and the misalignment range between the upper lip of the die and the lower lip of the die is 50-500 μm.