JP2017094552A - Film forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film forming apparatus in which the occurrence of coating film breakage on the film-formed sheet-shape material can be suppressed.SOLUTION: There is provided a film forming apparatus 1 having a 1'st roll 10 and a 2'nd roll 20 having a peripheral speed higher than that of the 1'st roll 10, horizontally arranged to face each other at a predetermined distance, and for forming an active material layer 120 by feeding a granule material 130 between these rolls from the vertical direction and compression forming the granule material 130, and in which the diameter of the 1'st roll 10 is set smaller than the diameter of the 2'nd roll 20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a film forming apparatus for compressing powder particles to form a film.

  Regarding a film forming apparatus, a film forming apparatus that forms a sheet by compressing a granular material is known. As one of this type of film forming apparatus, a pair of rolls arranged in parallel with each other at a predetermined interval and driven to rotate at different rotational speeds (circumferential speeds), and powder particles between the pair of rolls (facing position) Some have a hopper that feeds the body. And in this film-forming apparatus, the granular material supplied between a pair of rolls from the hopper is compression-molded with a pair of roll, and the sheet-like material is formed into a film (refer patent document 1).

JP2013-0777560A

  However, in the film forming apparatus described above, there is a speed difference between the rotation speeds (peripheral speeds) of the pair of rolls. Therefore, as shown in FIG. Since it is pulled, a shearing stress acts on the sheet-like material. For this reason, when the extensibility of the granular material is insufficient, the sheet-like material may not be able to withstand the acting shear stress, and the film may be broken, resulting in poor film formation.

  Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a film forming apparatus capable of suppressing the occurrence of a film break in a sheet-like material to be formed. And

  One aspect of the present invention made to solve the above problems includes a first roll and a second roll having a peripheral speed higher than that of the first roll, which are horizontally opposed to each other at a predetermined interval. In the film-forming apparatus which forms a sheet-like material by supplying powder particles in the vertical direction and compressing the powder particles, the diameter of the first roll is larger than the diameter of the second roll It is small.

  In this film forming apparatus, a sheet-like material is formed by compression-molding the granular material supplied between the rolls with a first roll and a second roll that are horizontally opposed to each other at a predetermined interval. And since the peripheral speed of a 2nd roll is quicker than the peripheral speed of a 1st roll, the sheet-like material formed into a film by compression-molding a granular material is wound around the 2nd roll with a faster peripheral speed. . At this time, since a shear stress acts on the sheet-like material, the coating film density is reduced on the first roll side where the peripheral speed is slower, and there is a possibility that the sheet-like material is cut off (see FIG. 3). ).

  However, in this film forming apparatus, the diameter of the first roll is set smaller than the diameter of the second roll. Thereby, the supply port area (per unit time) of the fall direction of the granular material to the 1st roll side with a slower peripheral speed can be enlarged (refer FIG. 2). Therefore, it is possible to increase the supply amount of the granular material to the first roll side having the slower peripheral speed. As a result, since the coating density on the first roll side with the lower peripheral speed is increased, it is possible to withstand the shear stress caused by the difference in roll speed, and thus it is possible to suppress the occurrence of film breakage on the sheet-like material. .

  According to the film-forming apparatus which concerns on this invention, it can suppress that a coating-film breakage generate | occur | produces in the sheet-like material formed into a film as above mentioned.

It is a schematic block diagram of the film-forming apparatus which concerns on embodiment. It is explanatory drawing about the supply port area in the fall direction of a granular material. It is a conceptual diagram which shows that a shear stress acts with respect to a sheet-like object by the speed difference of a roll.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying a film forming apparatus of the present invention will be described below in detail with reference to the drawings. In this embodiment, a case where the present invention is applied to manufacture of an electrode plate will be described. Therefore, a film forming apparatus (electrode plate manufacturing apparatus) according to the present embodiment will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of a film forming apparatus according to an embodiment. Drawing 2 is an explanatory view about the supply mouth area in the drop direction of a granular material.

  As shown in FIG. 1, the film forming apparatus 1 according to the present embodiment includes a first roll 10, a second roll 20, a third roll 30, and a powder body supply unit 40. Then, the film forming apparatus 1 forms an active material layer 120 as a sheet-like material obtained by compression molding the powder 130 supplied from the powder supply unit 40 with the first roll 10 and the second roll 20. It is supposed to be. In FIG. 1, the vertical direction is the vertical direction, and the gravity acts downward.

  The 1st roll 10 and the 2nd roll 20 are horizontally opposed, and are press rolls of the different diameter which compress-molds the granular material 130 supplied from the granular material supply part 40 in a sheet form. That is, the central axis 10O of the first roll 10 and the central axis 20O of the second roll 20 are arranged at the same height position, and the diameter of the first roll 10 is smaller than the diameter of the second roll 20. And the 1st roll 10 and the 2nd roll 20 are arrange | positioned in the state which each outer peripheral surface 11 and 21 mutually faced in the 1st facing position A.

  Such 1st roll 10 and 2nd roll 20 are hold | maintained so that the center distance may become a fixed space | interval. In addition, a predetermined gap (corresponding to a film thickness for film formation) is provided between the outer peripheral surface 11 of the first roll 10 and the outer peripheral surface 21 of the second roll 20 at the first facing position A.

  The 3rd roll 30 is a transfer roll which transfers the active material layer 120 shape | molded by the 1st roll 10 and the 2nd roll 20 to the current collector foil 110 which is a base material. A current collector foil 110 is wound around the outer peripheral surface 31 of the third roll 30, and the third roll 30 is located at a position where it does not interfere with the first roll 10 and the second roll 20, and the active material layer 120. As long as it can be transferred to the current collector foil 110, and as an example, it may be disposed directly under the second roll 20. And the 3rd roll 30 is hold | maintained so that the center distance with the 2nd roll 20 may become a fixed space | interval. In addition, a predetermined gap (corresponding to the thickness of the electrode plate to be manufactured) is provided between the outer peripheral surface 21 of the second roll 20 and the outer peripheral surface 31 of the third roll 30 at the second facing position B.

  The granular material supply part 40 supplies the granular material 130 accommodated in the inside between the 1st roll 10 and the 2nd roll 20 (the process area | region mentioned later) from a perpendicular direction by gravity fall. . As shown in FIG. 1, the powder body supply unit 40 is provided above the first facing position A where the first roll 10 and the second roll 20 face each other. For this reason, the granular material supply unit 40 supplies the granular material 130 to the first facing position A from above the first facing position A.

  The powder body 130 includes a powder material for forming the active material layer 120. The granular material 130 of the present embodiment includes an active material 121 and a binder 122. Further, the particles in the granular material 130 of the present embodiment are granulated particles obtained by granulating the active material 121 and the binder 122.

  The first roll 10, the second roll 20, and the third roll 30 rotate when the electrode plate 100 is manufactured. In FIG. 1, each rotation direction of the 1st roll 10, the 2nd roll 20, and the 3rd roll 30 is each shown by the arrow. As shown in FIG. 1, the rotation direction of the first roll 10 and the third roll 30 is clockwise, and the rotation direction of the second roll 20 is counterclockwise. That is, the first roll 10 and the second roll 20, and the second roll 20 and the third roll 30 that are arranged to face each other rotate in opposite directions.

  Here, the peripheral speed of the first roll 10 and the peripheral speed of the second roll 20 are different, and the peripheral speed of the second roll 20 is set faster than that of the first roll 10. As a result, the active material layer 120 formed into a sheet by compressing the powder body 130 by the first roll 10 and the second roll 20 is attached to the outer peripheral surface 21 of the second roll 20.

  In addition, the area | region (process area | region) where the granular material 130 is compression-molded by the 1st roll 10 and the 2nd roll 20 is a rotation direction only a predetermined dimension from the 1st facing position A in a rotation direction, as shown in FIG. This is a range from the upstream (upper) position C (upward from the first facing position A by an angle θ). Further, the processing region is in a predetermined length range (corresponding to the width of the active material layer to be formed) in the axial direction (front-rear direction in the drawing). In the processing region in such a range, the powder body 130 supplied from the powder body supply unit 40 is compression-molded by the first roll 10 and the second roll 20.

  Returning to FIG. 1, the current collector foil 110 as a base material is wound around the outer peripheral surface 31 of the third roll 30 as described above. The current collector foil 110 is wound around the third roll 30 with the second surface 112 side facing the outer peripheral surface 31 of the third roll 30. For this reason, the current collector foil 110 is conveyed by the rotation of the third roll 30.

  Further, the first surface 111 of the current collector foil 110 faces the outer peripheral surface 21 of the second roll 20 at the second facing position B. In addition, the 3rd roll 30 of this embodiment rotates so that the moving speed of the 1st surface 111 of the current collection foil 110 in the 2nd facing position B may become faster than the circumferential speed of the 2nd roll 20. FIG. It has become. As a result, at the second facing position B, the active material layer 120 wound around and conveyed on the second roll 20 is transferred to the first surface 111 of the current collector foil 110 wound around the third roll 30. It is like that.

  Next, the operation of the film forming apparatus 1 (production of the electrode plate 100) will be described. First, the granular material supply unit 40 supplies the granular material 130 to the first facing position A (processing region). At this time, the granular material 130 is supplied to the first facing position A by gravity drop. When the granular material 130 supplied to the first facing position A passes through the gap between the first roll 10 and the second roll 20 due to the rotation of the first roll 10 and the second roll 20, the powder 130 is passed through the gap. Pressurized (compressed) by the first roll 10 and the second roll 20. By this pressurization, the particles in the powder body 130 are bound to each other by the action of the binder 122 and the like in the powder body 130. Thereby, the granular material 130 which passed the 1st facing position A is shape | molded in a sheet form.

  And the granular material 130 pressurized by the 1st roll 10 and the 2nd roll 20 in the 1st facing position A is the 1st among the outer peripheral surface 11 of the 1st roll 10, and the outer peripheral surface 21 of the 2nd roll 20. It adheres to the surface with the higher moving speed at the facing position A. Therefore, the granular material 130 that has passed the first facing position A adheres as a sheet-like active material layer 120 on the outer peripheral surface 21 of the second roll 20 as shown in FIG. Then, the active material layer 120 attached on the outer peripheral surface 21 of the second roll 20 is transported to the second facing position B by the rotation of the second roll 20.

  Here, when the active material layer 120 adheres on the outer peripheral surface 21 of the second roll 20, a shear stress acts on the active material layer 120. Therefore, when tensile stress is generated on the first roll 10 side with the lower peripheral speed and the spreadability of the active material layer 120 is insufficient, the coating film may be cut off (see FIG. 3). ).

  However, in the film forming apparatus 1, the diameter of the first roll 10 is smaller than the diameter of the second roll 20. Therefore, the supply port area (per unit time) in the dropping direction of the granular material 130 toward the first roll 10 can be increased. As a result, since the coating film density on the first roll 10 side with the lower peripheral speed can be increased, even when the active material layer 120 has the same spreadability, the coating film breakage occurs. Can be suppressed.

The reason will be described with reference to FIG. Here, the following three specific examples including the conventional apparatus will be described.
Comparative example: When using a roll having the same diameter (radius R = 100 mm) as a conventional apparatus Example 1: When the radius of the first roll is 75 mm and the radius of the second roll is 100 mm Example 2: First roll When the radius of the second roll is set to 50 mm and the radius of the second roll is set to 100 mm, the film forming conditions are not changed. To do).

First, as shown in FIG. 2, assuming that the roll radius is R and the length of the machining region in the axial direction (front-back direction) is L, the supply port area of the powder 130 is “(R−R cos θ) L”. . Here, when the angle θ in the specific example 1 (conventional device) is θ = 5 °, the angle θ is determined as follows so that the roll peripheral speed is constant regardless of the roll diameter.
Comparative example: The radius of the first roll is 100 mm, and the angle θ is θ = 5 °.
Example 1: The radius of the first roll is 75 mm, and the angle θ is θ = 6.667 °.
Example 2: The radius of the first roll is 50 mm, and the angle θ is θ = 10 °.

Therefore, the supply port area in the dropping direction of the granular material 130 toward the first roll 10 in each specific example is as follows.
Comparative example: 0.381L
Example 1: 0.507L
Example 2: 0.760 L

  That is, the area of the supply port is “0.381L” in the conventional film forming apparatus (roll radius is 100 mm), whereas in the film forming apparatus 1, the radius of the first roll 10 is set to 3/4 ( In Example 1), it becomes “0.507L”, which is about 1.4 times. Further, when the radius of the first roll 10 is halved (Example 2), it becomes “0.760 L”, which is approximately doubled. Thus, by making the diameter of the first roll 10 smaller than the diameter of the second roll 20, the area of the supply port in the dropping direction of the granular material 130 is increased. As a result, the supply amount of the granular material 130 to the first roll 10 side increases and the coating film density increases. Thereby, since the active material layer 120 can endure the shear stress which arises by a roll speed difference, it can suppress that the coating material breakage generate | occur | produces in the active material layer 120. FIG.

Here, as a contradiction to reducing the roll diameter, there is a possibility that the depth of the processing region (length in the vertical direction) becomes large and supply of the powder body 130 cannot catch up. The depth of the processed region is “Rsin θ” as shown in FIG. However, it can be seen that the depth in each specific example is as follows and hardly changes.
Comparative example: 8.716 mm
Example 1: 8.707 mm
Example 2: 8.682 mm
That is, even if the diameter of the first roll 10 is reduced, there is almost no influence on the depth of the processing region.

  In addition, since the angle θ is a value determined by the characteristics of the powder and the like 130 and is an unknown number, it will be briefly described that the above effect can be obtained even when the angle θ is changed. As preconditions, the roll radius of the conventional apparatus is 100 mm and the angle θ is θ = 10 ° (the angle θ is twice that of the comparative example). On the other hand, in the film forming apparatus 1 of the present embodiment, when the radius of the first roll 10 is 50 mm, the angle θ is θ = 20 °. Accordingly, the area of the supply port in the dropping direction of the granular material 130 is “1.519L” in the conventional apparatus and “3.015L” in the film forming apparatus 1, and the supply port area is approximately doubled. On the other hand, the depth of the processing area is “17.365 mm” in the conventional apparatus and “17.101 mm” in the film forming apparatus 1, and there is almost no change, and it can be said that there is almost no influence on the depth of the processing area. Therefore, the above-described effect can be obtained by reducing the diameter of the first roll 10 regardless of the angle θ.

  In this way, the powder material 130 is formed into a film by the film forming apparatus 1, thereby forming the active material layer 120 with no paint film breakage. Then, as shown in FIG. 1, the active material layer 120 is conveyed to the second facing position B by the second roll 20. At the second facing position B, the current collector foil 110 is passed by conveyance. For this reason, the active material layer 120 that has reached the second facing position B due to the rotation of the second roll 20 passes through the gap between the second roll 20 and the third roll 30 together with the current collector foil 110. When passing through the gap, the current collector foil 110 and the active material layer 120 are pressed against the second roll 20 and the third roll 30 in the thickness direction. In addition, at the second facing position B, the active material layer 120 is transferred from the outer peripheral surface 21 of the second roll 20 onto the first surface 111 of the current collector foil 110. Thus, the electrode plate 100 is manufactured.

  As described above in detail, according to the film forming apparatus 1 according to the present embodiment, the diameter of the first roll 10 with the slower peripheral speed is set smaller than the diameter of the second roll 20. Thereby, since the supply port area in the fall direction of the granular material 130 to the first roll 10 side having the slower peripheral speed is increased and the supply amount of the granular material 130 is increased, the coating film on the first roll 10 side is increased. A decrease in density can be prevented. Therefore, it is possible to prevent the active material layer 120 from being broken.

  It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention.

DESCRIPTION OF SYMBOLS 1 Film-forming apparatus 10 1st roll 20 2nd roll 30 3rd roll 40 Granule supply part 100 Electrode plate 120 Active material layer 130 Powder

Claims (1)

A first roll and a second roll having a peripheral speed faster than the first roll, which are horizontally opposed to each other at a predetermined interval, are supplied between the rolls in a vertical direction, and the powder is supplied by the powder. In a film forming apparatus for forming a sheet-like material by compression molding,
The film forming apparatus, wherein the diameter of the first roll is smaller than the diameter of the second roll.

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