System for bonding films and method for using same to produce composite films

Abstract

To provide a system for joining films and a method for producing composite films using the system.SOLUTION: A system for joining films includes a first film, a second film with a plurality of elements, a joining roller, and a deformable roller with a deformable outer layer. The stiffness of the second film is lower than the stiffness of the first film. By using this system, the deformable outer layer of the deformable roller deforms sufficiently to fill the areas in the second film that are not covered by the plurality of elements during joining of the films. Thus, the second film, which is not rigid enough, and the first film can be joined to each other to produce a wrinkle-free composite film. Methods for producing composite films using this system are also disclosed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a system for splicing films, and in particular to a system including a deformable roller having a deformable outer layer for splicing films, and a method for producing a composite film using the same. [Background technology]

[0002] In recent years, various electronic products have been developed to be lighter, thinner, and more compact, expanding the scope of application of film bonding technology. The most common film bonding technology is the roll-to-roll method, which is a highly efficient continuous production method specialized for flexible thin films. In this method, a cylindrical substrate and a cylindrical thin film material to be bonded are pressed together with a roller to achieve a continuous bond. Once bonded, the product can be rolled into a cylindrical shape or cut into a semi-finished product for subsequent processing.

[0003] The main point in thin film bonding is how to bond thin films without wrinkles and make the laminate flat. In Patent Document 1, an insulating film, a metal foil, a spacing film, a metal foil, and an insulating film are mainly bonded by thermocompression bonding, and two single-sided metal-clad laminates are separated from the spacing film to achieve flat bonding.

[0004] However, when elements are present on the backside of the films to be bonded, these elements form three-dimensional obstacles with gap spaces between them. In addition, the film is relatively thin and does not have sufficient rigidity, which causes wrinkles when bonded to other films, resulting in an uneven composite film. There are many techniques for improving the flatness of thin film bonding, but these techniques do not take into account situations where there are three-dimensional obstacles, and they require the production machine to be stopped during the process to manually remove wrinkles, which results in a relatively slow production speed and increased labor costs.

[0005] Thus, the present invention provides a system for joining films, and a method for using the same to produce composite films, that overcomes the conventional drawbacks caused by three-dimensional obstacles. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] WO2011093427A1 publication Summary of the Invention [Problem to be solved by the invention]

[0007] The object of the present invention is to provide a system for bonding films and a method for manufacturing a composite film using the same, which overcomes the above drawbacks. The surface of the manufactured composite film is wrinkle-free, so there is no need to stop the production machine to increase the production speed. In addition, there is no need for additional manual work to remove wrinkles, which reduces labor costs. [Means for solving the problem]

[0008] To achieve the above, the present invention discloses a system for bonding films, including a first film, a second film, a bonding roller, and a deformable roller. The first film has a first surface and a second surface opposite the first surface, and the second film has a first surface and a second surface opposite the first surface. The first surface of the second film is configured to be oriented toward the first surface of the first film. The second film has a lower stiffness than the first film. The second surface of the second film includes a plurality of elements and at least one gap space not covered by the elements. The bonding roller is configured to contact the second surface of the first film. The deformable roller is configured to contact the second surface of the second film and is positioned adjacent to the bonding roller. The deformable roller has a deformable outer layer, and the deformable outer layer of the deformable roller deforms to fill at least one gap space in the second surface of the second film. The bonding roller is configured to indirectly contact the deformable roller via the first and second films, and the deformable roller is configured to indirectly contact the bonding roller via the first and second films. By using this system, the deformable outer layer of the deformable roller deforms sufficiently to fill gap spaces in the second film that is not sufficiently rigid during bonding of the films. Therefore, the second film that is not sufficiently rigid and the first film can be bonded together to produce a wrinkle-free composite film.

[0009] According to an embodiment of the present invention, each of these elements is a component associated with a battery.

[0010] According to an embodiment of the present invention, the distance between two adjacent elements is between 2 and 150 millimeters.

[0011] According to an embodiment of the present invention, the deformable roller includes an inner roller covered by a deformable outer layer.

[0012] According to an embodiment of the present invention, the hardness of the outer deformable layer of the deformable roller is between 15 Shore A and 50 Shore A.

[0013] According to an embodiment of the present invention, the thickness of the deformable outer layer of the deformable roller is between 1 and 4 millimeters.

[0014] According to an embodiment of the present invention, the outer deformable layer of the deformable roller is made of a polymer.

[0015] According to an embodiment of the present invention, the outer deformable layer of the deformable roller is porous.

[0016] According to an embodiment of the present invention, the bonding roller has a higher Shore A hardness than the deformable roller.

[0017] The present invention also provides a method for manufacturing a composite film by using the above-described system for bonding films, the method including the steps of receiving a first film by a bonding roller and pressing a first side of the first film against a first side of a second film, receiving a second film by a deformable roller and pressing the first side of the second film against the first side of the first film, wherein the deformable outer layer of the deformable roller deforms to fill at least one gap space in the second side of the second film, and obtaining a composite film in which the first film is bonded to the second film.

[0018] Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. [Effects of the Invention]

[0019] The present invention will be more fully understood from the detailed description given below, which is by way of example only and is therefore not intended to limit the invention. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic diagram of an embodiment of a system for bonding films of the present invention. [Figure 2] 1 is a schematic diagram of an embodiment of a deformable roller of a system for splicing films of the present invention. [Figure 3] FIG. 2 is a side view of an embodiment of a system for splicing films of the present invention showing a deformable roller and a splicing roller simultaneously pressing a first film and a second film together. [Figure 4A] FIG. 2 is a schematic diagram of an embodiment of a system for splicing films of the present invention showing a deformable roller and a splicing roller simultaneously pressing a first film and a second film together. [Figure 4B] FIG. 2 is a cross-sectional view of an embodiment of a system for splicing films of the present invention showing a deformable roller and a splicing roller simultaneously pressing a first film and a second film together. [Figure 5A] FIG. 2 is a schematic diagram of another embodiment of a system for bonding films of the present invention. [Figure 5B] FIG. 2 is a schematic diagram of another embodiment of a system for bonding films of the present invention. [Figure 6] FIG. 1 is a flow diagram of a method for manufacturing a composite film by using the film bonding system of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] 1 is a schematic diagram of an embodiment of a system for splicing films of the present invention. The system for splicing films includes a first film 50, a second film 40 including a plurality of elements 41, a first feed roller 31, a second feed roller 32, a splicing roller 21, and a deformable roller 22 including a deformable outer layer 221.

[0022] The first film 50 is guided to the bonding roller 21 by the first feed roller 31, and the second film 40 is guided to the deformable roller 22 by the second feed roller 32. The bonding roller 21 is configured to receive the first film 50 and indirectly contact the deformable roller 22 via the first film 50 and the second film 40, thereby pressing the first film 50 against the second film 40. The deformable roller 22 is also configured to receive the second film 40 and indirectly contact the bonding roller 21 via the first film 50 and the second film 40, thereby pressing the second film 40 against the first film 50. While pressing the second film 40, the deformable outer layer 221 of the deformable roller 22 deforms sufficiently to fill in areas of the second film 40 that are not covered by the multiple elements 41. Thus, the second film 40 and the first film 50 can be bonded together to produce a wrinkle-free composite film. It should be noted that the description herein is for illustrative purposes only and is not intended to limit the number or location of rollers. In other embodiments, if there are more than two films to be bonded together, the number of feed rollers increases accordingly.

[0023] The first film 50 has a first surface 501 and a second surface 502 opposite to the first surface 501. The first surface 501 is configured to be oriented toward the second film 40, and the first surface 501 of the first film 50 is bonded to the second film 40. The thickness of the first film 50 can range from a few micrometers to several thousand micrometers (μm). The first film 50 is a PET (polyethylene terephthalate) or other plastic film with sufficient rigidity.

[0024] The second film 40 has a first surface 401 and a second surface 402 opposite to the first surface 401. The first surface 401 is configured to be oriented toward the first film 50, and the first surface 401 of the second film 40 is bonded to the first surface 501 of the first film 50. The thickness of the second film 40 is approximately 0.001 to 0.02 millimeters (mm), preferably 0.004 to 0.006 mm. The second film 40 is a metal film such as a copper thin film or an aluminum thin film. The second surface 402 of the second film 40 includes a plurality of elements 41 and an area not covered by the elements 41. In the area not covered by the elements 41, a gap 411 is defined between two adjacent elements 41. Thus, at least one gap 411 exists on the second surface 402 of the second film 40. The height of each element 41 is 40 to 200 micrometers. The distance between two adjacent elements 41 is 2 to 150 millimeters. The elements 41 are components related to the battery, such as a positive electrode active material layer, a negative electrode active material layer, an adhesive frame, etc. Furthermore, the elements 41 can be the same or different components related to the battery. In one embodiment, the elements 41 can be one of a positive electrode active material layer, a negative electrode active material layer, or an adhesive frame. In another embodiment, the elements 41 can be a positive electrode active material layer, a negative electrode active material layer, or an adhesive frame, respectively.

[0025] In an embodiment, an adhesive substance is applied to the first surface 501 of the first film 50 for bonding to the first surface 401 of the second film 40. The adhesive substance is a sticky adhesive or a sticky gel.

[0026] In the present invention, the second film 40 has a lower rigidity than the first film 50. Rigidity is the ability of a thin film to resist bending. Therefore, in the present invention, since the second film 40 has a lower rigidity than the first film 50, the second film 40 is more prone to wrinkling than the first film 50.

[0027] The bonding roller 21 receives the first film 50 guided by the first feed roller 31 and continuously contacts the second surface 502 of the first film 50. The bonding roller 21 can be any type of hollow or solid roller, such as a steel roller or a rubber-coated roller. The bonding roller 21 has a higher Shore A hardness than the deformable roller 22.

[0028] The deformable roller 22 is positioned adjacent to the bonding roller 21. The deformable roller 22 receives the second film 40 guided by the second feed roller 32. As shown in FIG. 2, the deformable roller 22 has a deformable outer layer 221 and an inner roller 222 covered by the deformable outer layer 221. The thickness of the deformable outer layer 221 is 1 to 4 millimeters and is made of a soft polymer or is porous. For example, the polymer may be rubber, but is not limited to this. The diameter of the inner roller 222 is 50 to 250 millimeters. The inner roller 222 may be a solid or hollow steel or aluminum roller. The hardness of the deformable outer layer 221 is 15 Shore A to 50 Shore A.

[0029] 3, the second surface 402 of the second film 40 has a plurality of elements 41. The elements 41 have a certain thickness and weight, and therefore a certain mechanical strength. Therefore, the rigidity of the area of ​​the second film 40 covered by the elements 41 can be increased. The areas of the second film 40 that are not covered by the elements 41 are not supported by the elements 41, and therefore wrinkles are likely to occur, particularly in the gap spaces 411 between two adjacent elements 41 on the second surface 402. Therefore, in the present invention, the deformable outer layer 221 of the deformable roller 22 is sufficiently deformed to fill and press the areas of the second surface 402 of the second film 40 that are not covered by the elements 41 during bonding of the films. In particular, the deformable outer layer 221 is sufficiently deformed relative to the elements 41 on both sides to fill the gap spaces 411, thereby increasing the mechanical strength of this area during bonding. Therefore, when the deformable roller 22 presses the second film 40 and the bonding roller 21 presses the first film 50, the first film 50 and the second film 40 are bonded flat to each other, producing a wrinkle-free composite film.

[0030] FIG. 4A is a schematic diagram showing how deformable roller 22 and bonding roller 21 press first film 50 and second film 40, respectively. The bonding roller 21 presses the first surface 501 of the first film 50 against the first surface 401 of the second film 40. The deformable roller 22 also presses the first surface 401 of the second film 40 against the first surface 501 of the first film 50, bonding the first film 50 and the second film 40 together. In the figure, the elements 41 on the second surface 402 of the second film 40 are arranged in a matrix, but they may also be arranged irregularly.

[0031] FIG. 4B is a cross-sectional view taken along the center line of the rotation axis of the deformable roller 22 and the center line of the rotation axis of the joining roller 21. FIG. 4B , the bonding roller 21 presses the first surface 501 of the first film 50 against the first surface 401 of the second film 40, and the deformable roller 22 presses the first surface 401 of the second film 40 against the first surface 501 of the first film 50. Specifically, the deformable outer layer 221 of the deformable roller 22 deforms sufficiently to fill and press areas of the second surface 402 of the second film 40 that are not covered by the plurality of elements 41. In particular, the deformable outer layer 221 deforms sufficiently to fill the interstitial spaces 411 between adjacent elements 41. Thus, the first film 50 and the second film 40 can be bonded to produce a wrinkle-free composite film.

[0032] The deformable outer layer 221 may have multiple holes 2211 inside, as shown in Figure 5A, or multiple holes 2212 on its outer surface, as shown in Figure 5B. These types of deformable outer layers 221 can deform sufficiently to fill the interstitial spaces 411 between adjacent elements 41 during bonding.

[0033] FIG. 6 is a flow diagram of a method for producing a composite film by using the film bonding system of the present invention. The method for manufacturing a composite film includes providing a first film 50 in step S601, providing a second film 40 in step S602, guiding the first film 50 to a bonding roller 21 by a first feed roller 31 and guiding the second film 40 to a deformable roller 22 by a second feed roller 32 in step S603, and receiving the first film 50 by the bonding roller 21 and deforming the first film 50 in step S604. the surface 501 of the second film 40 being pressed against the first surface 401 of the second film 40, the deformable roller 22 receiving the second film 40, and the deformable outer layer 221 of the deformable roller 22 being pressed against the first surface 501 of the first film 50, so that the deformable outer layer 221 of the deformable roller 22 deforms to fill at least one gap space 411 in the second surface 402 of the second film 40; and in step S605, obtaining a composite film in which the first film 50 is bonded to the second film 40.

[0034] As described above, the present invention provides a system for joining films, which is particularly suitable for films having multiple elements and lacking sufficient rigidity, in order to solve the problem of wrinkles occurring when a film that does not have sufficient rigidity is joined to another film, and a method for manufacturing a composite film using the system. The system of the present invention includes a deformable roller that deforms sufficiently during bonding to fill the interstitial spaces between elements of the film that lack sufficient stiffness, thus allowing the film that lacks sufficient stiffness to be bonded flat to other films to produce a wrinkle-free composite film.

[0035] The invention being thus described, it will be apparent that the same may be modified in various ways. Such modifications should not be regarded as a departure from the spirit and scope of the invention, and all modifications as would be apparent to one skilled in the art are intended to be included within the scope of the following claims. [Explanation of symbols]

[0036] 21 Bonding roller 22 Deformable roller 31 First feed roller 32 Second feed roller 40 Second Film 41 elements 50 First Film 221 Deformable outer layer 222 Inner roller 401 First Side 402 Second Side 411 Interstitial Space 501 First Side 502 Second Side 2211 holes 2212 hole

Claims

1. 1. A system for splicing films, comprising: a first film having a first surface and a second surface opposite the first surface; a second film having a lower stiffness than the first film and having a first surface and a second surface opposite to the first surface, the second film being configured to be oriented with the first film such that the first surfaces of the second film are oriented relative to each other, and the second surface of the second film is configured to include a plurality of elements and at least one interstitial space not covered by the plurality of elements; a bonding roller configured to contact the second surface of the first film; a deformable roller configured to contact the second surface of the second film and positioned adjacent to the bonding roller; the deformable roller has a deformable outer layer; the deformable outer layer of the deformable roller deforms to fill the at least one interstitial space in the second surface of the second film; the bonding roller is configured to indirectly contact the deformable roller via the first film and the second film; the deformable roller is configured to indirectly contact the bonding roller via the first film and the second film; the joining roller has a higher Shore A hardness than the deformable roller; A system for joining films.

2. 2. The system for splicing films according to claim 1, wherein each of said plurality of elements is a component associated with a battery.

3. 2. The system for splicing films according to claim 1, characterized in that the distance between two adjacent elements is between 2 and 150 millimeters.

4. 10. The system for splicing films of claim 1, wherein the deformable roller comprises an inner roller covered by the deformable outer layer.

5. 10. The system for bonding films of claim 1, wherein the deformable outer layer of the deformable roller has a hardness of 15 Shore A to 50 Shore A.

6. 6. The system for splicing films according to claim 5, wherein the thickness of the deformable outer layer of the deformable roller is between 1 and 4 millimeters.

7. 7. The system for splicing films of claim 6, wherein the deformable outer layer of the deformable roller is made of a polymer.

8. 8. The system for bonding films of claim 7, wherein the deformable outer layer of the deformable roller is porous.

9. 10. A method for producing a composite film by using the system for joining films according to claim 1, comprising: receiving the first film by the bonding roller and pressing the first surface of the first film against the first surface of the second film; receiving the second film by the deformable roller and pressing the first surface of the second film against the first surface of the first film, wherein the deformable outer layer of the deformable roller deforms to fill the at least one interstitial space in the second surface of the second film; and obtaining the composite film wherein the first film is bonded to the second film. method.

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