JP2508518B2 - Paint applicator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coating material application device, and is particularly suitable for application to a magnetic coating material on a magnetic tape or a magnetic sheet.

SUMMARY OF THE INVENTION According to the present invention, a bending moment is applied to at least one roll shaft of a pair of rolls that presses a non-magnetic support at a predetermined pressure, at a shaft fulcrum thereof or at a portion isolated from the shaft fulcrum. By doing so, the bending in the operating portion of the rolls is offset and removed, and both rolls are pressed with a substantially uniform pressure so that the coating material is applied with a uniform thickness on the non-magnetic support.

[Conventional technology]

For example, in the production of a magnetic tape, as a device for applying a magnetic coating material to a non-magnetic support, that is, a base film with a thin coating pressure, there is, for example, a gravure roll coating device disclosed in Japanese Patent Publication No. 58-45090. .

This gravure roll coating will be described with reference to FIG. 9. (1) is a film-shaped non-magnetic support, and this non-magnetic support (1) is provided from a supply roll (2) to a guide roller (3). It is sent through between the backup roll (4) and the gravure roll (5) via.

The backup roll (4) and the gravure roll (5) sandwich the non-magnetic support (1) with a predetermined nip pressure, and the non-magnetic support (1) is rotated while rotating both rolls (4) (5). By the transfer, the gravure roll (5) sucks up the magnetic paint (7) stored in the application dish (6), and transfers and applies the magnetic paint onto one surface of the non-magnetic support (1).

Then, the coated surface of the magnetic paint (7) is smoothed by a smoother (8), and then the non-magnetic support (1) coated with the magnetic paint (7) is passed through a drier (9) and dried. It is designed to be wound on a winding roll (10).

[Problems to be solved by the invention]

In this gravure roll coating apparatus, rolls having a large width have been used in recent years to perform wide coating, and therefore both rolls (4) and (5) have a reaction force at the nip portion due to the nip pressure applied therebetween. Upon receiving it, it is easily elastically deformed, that is, it bends in an arc shape so that the distance between the central operating portions increases as shown in FIG.

Therefore, the coating amount of the magnetic coating material (7) on the non-magnetic support (1) by the gravure roll (5) is greatly different between the central portion and both end portions, that is, coating unevenness occurs. Therefore, the thickness of the magnetic layer is partially different, and when the magnetic layer is wound around the winding roll (10), only the portion with a large thickness of the magnetic layer rises, which causes the magnetic layer to wrinkle, Deformation may occur in the non-magnetic support (1), which requires cutting and discarding the wrinkled or deformed portion, which is a major obstacle to cost reduction.

In order to solve this, conventionally, a method has been adopted in which the diameters of the rolls (4) and (5) are made sufficiently large to increase the strength and the amount of deflection with respect to the nip pressure is reduced, but the entire apparatus becomes large. However, there is a problem that the weight becomes large.

Further, assuming the elastic deflection amount of the rolls (4) and (5) in advance, crowning the peripheral surfaces of the rolls (4) and (5),
It may be possible to machine the moving part into a bulged shape by cambering or the like, but this requires a very high machining accuracy, and there is a problem that the manufacturing cost becomes large.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a coating material coating device that can suppress the bending of a roll with a simple configuration and can perform coating with a uniform thickness.

[Means for solving problems]

In order to achieve the above-mentioned object, the apparatus of the present invention is an apparatus for applying a paint while pinching and transferring a non-magnetic support at a predetermined pressure by a pair of rolls, that is, a backup roll and a gravure roll, and at least one of both rolls. The roll supporting shaft is provided with a load mechanism for applying a bending moment to the shaft in order to remove the bending in the working part of the roll, at the shaft supporting portion of the roll or at a position separated from the shaft supporting portion at a required interval.

[Action]

When a bending moment is applied to the roll axis like this,
This bending moment cancels out the elastic bending due to the nip pressure of the roll, so that the bending of the moving part of the roll is removed and the nip pressure becomes uniform over the entire width, so that the non-magnetic support should be coated with a uniform thickness. You can

〔Example〕

Hereinafter, the embodiment of the present invention will be described with reference to FIGS. 1 to 8. The same reference numerals are given to the portions corresponding to the conventional example of FIG. 9 described above.

1 to 5 show a first embodiment of the apparatus of the present invention. In this coating apparatus, the backup roll (4) and the gravure roll (5) are arranged in opposition to each other in the upper and lower frames ( It is supported by 11) and (12).
That is, the upper and lower frames (11) and (12) have both arm portions (11
a) A rectangular cylindrical housing (13) is projectingly fixed to the ends of a) (11b), (12a) and (12b), respectively, and both rolls (4) and (5) are fixed to the housing (13). Axis (4a)
And (5a) are axially supported at a predetermined interval between the roll-side portion and the tip end portion extending outward from the roll-side portion. The portions of the shafts (4a) and (5a) near the roll are fixedly supported by the housing (13) via the bearing (14) (in this example, this portion is referred to in the claims). The end portion is pivotally supported by a slider (19) of a load mechanism described later via a bearing (20). The shafts (4a) and (5a) are both supported by spherical shafts (4a ₁ ) (4a ₂ ), which allows the shafts (4a) and (5a) to tilt with respect to the axial direction. It is designed to be able to.

A hydraulic cylinder (15) is connected to the upper surface of the upper frame (11) on which the backup roll (4) is pivotally supported, and the backup roll (4) is directed downward by the cylinder (15), that is, the gravure roll (5). Therefore, both rolls (4) and (5) are in a state of being applied with a predetermined nip pressure so as to clamp the non-magnetic support (1) from both upper and lower surface sides. The nip pressure between the rolls (4) and (5) is controlled by a gap controller (16) interposed between the upper and lower frames (11) and (12).

Then, in order to remove the bending of both rolls (4) and (5) due to this nip pressure, a bending moment is applied to the shafts (4a) and (5a) by a load mechanism (18) provided in the housing (13). Has been done.

The load mechanism (18) will be described in detail with reference to FIGS. 2 and 3. In FIG. 2, one side arm portion (11) of the upper frame (11) on which the backup roll (4) is pivotally supported is shown.
Only the load mechanism (18) on the side a) is shown. A slider (19) is arranged at the outer end of the housing (13), and a support hole (19a) is formed in the slider (19).
The tip end of the shaft (4a) is inserted and supported through the bearing (20).

Guide pieces (21) are provided on both side edges of the slider (19) in a protruding manner, and the guide pieces (21) are fitted into guide grooves (22) vertically formed on the inner surface of the housing (13), As a result, the slider (19) is adapted to slide vertically in a direction orthogonal to the shaft (4a).

The lower edge of the slider (19) is a slanted edge (2
3), and a wedge-shaped actuation block (24) is interposed between the inclined edge (23) and the lower side surface of the housing (13), and the actuation block (24) includes the housing (1
Actuator (25) fixed to 3) Actuating screw shaft (2
5a) is screwed and connected.

The actuator block (24) is moved forward by the rotation of the actuator screw shaft (25a) driven by the actuator (25), so that the slider (19) is pushed upward, so that the tip of the shaft (4a) is not moved. , Upward, that is, the load is applied in the direction opposite to the nip direction of the backup roll (4). The amount of pressure applied by the actuator (25) is controlled by the load sensor.

The backup roll (4) is shown in FIGS. 2 and 3.
Although only the load mechanism (18) on one side arm (11a) side of the upper frame (11) on which the shaft is pivotally supported is shown, the upper frame (11)
The same load mechanism (18) on the other arm (11b) side
Are provided symmetrically, and the load mechanism (18) provided on both side arm portions (12a) (12b) of the lower frame (12) on which the gravure roll (5) is pivotally supported is also configured in the same manner. . However, in the case of the load mechanism (18) of this lower frame (12), the direction of the load applied to the tip of the shaft (5a) should be opposite to that in the case of the load mechanism (18) of the upper frame (11). That is, the upper edge of the slider (19) on which the tip of the shaft (5a) is supported is a slant edge (23), and the upper slant edge (23) and the housing (13) are above the slant edge (23). The actuation block (24) is interposed between the side surfaces, and the forward movement of the actuation block (24) driven by the actuator (25) pushes the slider (19) downward, whereby the tip of the shaft (5a). The load is applied downwardly, that is, in the direction opposite to the nip direction of the gravure roll (5).

In this way, the load is applied to the tip blocks of the shafts (4a) and (5a) of both rolls (4) and (5) in the direction orthogonal to the shafts by the load mechanism (18), so that both rolls (4) and A bending moment is applied to the shafts (4a) and (5a) of (5) so that the moving parts of both rolls (4) and (5) are pressed against each other as shown in FIG. Therefore, the bending moment cancels the above-mentioned deflection of the rolls (4) and (5) due to the nip pressure, and the rolls (4) and (5) are respectively centered on straight lines a ₄ and a as shown in FIG. _The difference in deflection with respect to ₅ is reduced, that is, the elastic deflection amount is reduced, so that the nip pressure between both rolls (4) and (5) becomes uniform over the entire width.

Therefore, the thickness of the magnetic paint transferred from the gravure roll (5) to the non-magnetic support (1) is constant,
It is possible to obtain a magnetic tape of good quality without coating unevenness, the magnetic layer is wrinkled as in the conventional case, and the support (1) is used.
Since it does not deform, there is no part to cut and discard, which is also effective in terms of cost.

In addition, in this coating apparatus, it is not necessary to upsize both rolls (4) and (5) in order to maintain the strength, and the diameter may be the same as that of the conventional roll, so that the roll alone can be easily handled. The weight and cost can be suppressed, and in the production of both rolls (4) and (5), special processing such as crowning and cambering is not required,
Since the same straight shape processing as in the past is sufficient, the manufacturing cost does not increase.

The magnitude of the bending moment applied to the shafts (4a) and (5a) is set according to the nip pressure between the rolls (4) and (5). When the nip pressure between the two is changed, the load mechanism (18) is actuated by the actuator (25) accordingly, and the magnitude of the load applied to the tips of the shafts (4a) and (5a) is controlled. It

Next, an example of the most preferable configuration for actually manufacturing and using the apparatus of this example configured as described above will be described.

Both rolls (4) and (5) in the apparatus of this example are made of a metal material having physical properties such as a longitudinal elastic modulus of 21000 kg / mm ² or more and a density of 7.86 or less, for example, iron, and the backup roll (4) has its peripheral surface. Rubber is adhered as a cushioning material, and each has a diameter of 250 to 400 mm and a width of 1200 to 1400 mm.

When the nip pressure applied between the two rolls (4) and (5) is set to a linear pressure of 0.8 to 3.0 kgf / mm, the shaft (4a) is opposed to the nip pressure between the two rolls (4) and (5). The difference between the maximum and minimum values of elastic deflection from the center straight line of each roll (4) or (5) is set by setting the bending moments applied to 0.
1-2 μm, that is 0.2 between both rolls (4) and (5)
It can be a small value of ˜4 μm.

In this case, if the span from the shaft support of the shafts (4a) and (5a) to the load pressurizing part by the load mechanism (18) is 550 mm, the load mechanism (1
8) By the end of shaft (4a) and (5a) by 1200-6400kgf
The load of should be applied. The shaft diameters of the shaft support portions (4a) and (5a) and the load pressurizing portion must be 90 mm or more in terms of strength.

Then, by both rolls (4) and (5) that apply bending moment to the shafts (4a) and (5a) in this way, 4 to 50 μm
When a magnetic coating having a viscosity of 1000 to 12000 cps is transfer-coated at a coating thickness of 0.5 to 8 μm on a non-magnetic support (1) made of PET having a thickness of m, the coating thickness unevenness is ± 0.04 to 0.5.
It can be set to an extremely small value of μm.

Next, a second embodiment of the present invention will be described with reference to FIGS. 6 to 8. In FIGS. 6 to 8 as well, the upper frame (11) on which the backup roll (4) is axially supported. 2) only the configuration on the side of the one arm (11a) is shown.

In the second embodiment, the load mechanism (28) for applying a bending moment to the shaft (4a) is integrated with the shaft support portion of the shaft (4a). That is, one arm (11
A bearing block (29) is fixed to a), and a cylindrical support member (31) is provided in a circular support hole (30) formed in the bearing block (29) in the front-rear direction orthogonal to the shaft hole (29a). Is rotatably fitted, and a bearing hole (31a) which is orthogonal to the axial direction and communicates with the shaft hole (29a) is formed in the center of the cylindrical support member (31). There is. Then, the shaft (4a) passing through the shaft hole (29a) of the bearing block (29) is supported by the bearing hole (31a) via the inner and outer bearings (32) and (33) (in this example, , This portion corresponds to the "shaft support" in the claims). In addition, a lever (3
4) is fixed, and the tip of this lever (34) is pressed by a cylinder (36) fixedly supported by a U-shaped support frame (35) fixed to the upper frame (11) to form a cylindrical shape. Shaft (4a) by applying turning force to the support member (31)
A bending moment in a direction that cancels the bending due to the nip pressure is applied to the.

The load mechanism (28) is connected to the upper frame (1
1) Both side arm parts (12a) of the lower frame (12), which is also provided on the other side arm part (11b) side symmetrically with one side arm part (11a) side, and on which the gravure roll (5) is pivotally supported. ) (12b) is provided in the same manner. However, in the case of the load mechanism of the lower frame (12), the arrangement of the cylinder (36) is reversed from that in the case of the upper frame (11), and the bending moment applied to the shaft (5a) is set in the opposite direction.

Even when the load mechanism (28) and the shaft supporting portions of the shafts (4a) and (5a) are integrally formed as in the second embodiment, the shafts (4a) and (5a) are connected to the shafts (4a) and (5a) as in the first embodiment. Since it is possible to apply a bending moment that cancels the deflection due to the nip pressure of both rolls (4) and (5), both rolls (4) and (5)
It is possible to eliminate the bending of the moving part and make the thickness of the magnetic paint applied to the non-magnetic support (1) uniform.

The load mechanisms (18) and (28) are provided on the upper and lower support frames (11) and (12) as described above, and the bending moment is applied to the shafts (4a) and (5a) of both rolls (4) and (5). It is best to add one support frame (1
A load mechanism may be provided only in 1) or (12), that is, a bending moment may be applied only to the shaft (4a) or (5a) of one roll (4) or (5). The result is obtained. The drive mechanism of the load mechanisms (18), (28) is not limited to the one shown in the figure, and other actuators can be used.

Further, the device of the present invention is not limited to the application of the magnetic paint as described above, but can be applied to so-called back coating applied to the surface opposite to the magnetic surface in a video tape or the like, and is not limited to magnetic tapes. Instead, it can be applied to all apparatuses that apply by applying a nip pressure between a pair of rolls and allowing them to pass.

〔The invention's effect〕

As described above, in the device of the present invention, the bending mechanism applies a bending moment to at least one roll shaft of a pair of rolls that presses the non-magnetic support at a predetermined pressure. It is offset by the bending moment and removed, so that the nip pressure of the roll becomes uniform over the entire width, so that the coating material can be applied with a uniform thickness on the non-magnetic support, that is, the coating material can be applied stably.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing a first embodiment of the device of the present invention, FIG. 2 is a vertical sectional front view of a main portion thereof, and FIG.
FIG. 4 is a schematic side view of the roll in a state in which a bending moment is applied, FIG. 5 is a schematic view of the roll in a state where deflection is reduced, and FIG. 6 is a second embodiment of the device of the present invention. FIG. 7 is the same perspective view, FIG. 8 is the same exploded view, FIG. 9 is the same exploded perspective view, FIG. 9 is a schematic view of the gravure roll coating device, and FIG. It is explanatory drawing of a state. In the figure, (1) is a non-magnetic support, (4) is a backup roll, (4a) is its axis, (5) is a gravure roll, and (5)
a) is its axis, and (18) and (28) are load mechanisms.

Claims (1)

(57) [Claims] 1. An apparatus for applying a coating material while pressing a non-magnetic support by a pair of rolls while sandwiching it at a predetermined pressure, and at least one of the pair of rolls is required to have a shaft supporting portion of a shaft or a shaft supporting portion. A paint applicator, characterized in that a load mechanism for applying a bending moment to the shaft is provided at the portions separated by intervals so as to remove the flexure in the moving part of the roll.