JPH09173936A - Nip roll type die coater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately keep a gap between the tip lip part of a die body and a belt-shaped base material in an initializing state irrespective of a change in plate thickness of the belt-shaped base material in die coating. SOLUTION: This nip roll type die coater 1 is provided with a die body 2 opposite a belt-shaped base material W supported on a backup roll 100 and continuously conveyed leaving a prescribed space 'g' movably forwards and backward in the radial direction toward a central axis 101 of the backup roll 100 and follow-up moving mechanisms 27, 28, 29 by which a nip roll 10 which is rotatable while the belt-shaped base material W is held between it and the backup roll 100 is energized so as to make it movable forwards and backwards in the radial direction towards the central axis 101 of the backup roll 100 on the upstream side in the conveying direction of the belt-shaped base material W and by which the die body 2 is moved forwards and backwards by the same travel amt. as that of the nip roll 10 moved forward and backward with a change in plate thickness of the belt-shaped base material W.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nip roll type die coater, and more specifically, in a die coater for coating a belt-shaped substrate which is supported by a backup roll and continuously conveyed, a backup roll is provided on a support base for supporting a die body. A nip roll that rotates while holding the strip-shaped substrate between is provided, and the die body is moved back and forth with respect to the backup roll by the same amount as the minute movement amount of the nip roll due to the plate thickness change of the strip-shaped substrate. The present invention relates to a nip roll type die coater that maintains a constant gap.

[0002]

2. Description of the Related Art In die coater coating, in order to form a glossy coating surface with a uniform coating thickness on a strip-shaped substrate, the gap between the tip lip of the die body and the substrate surface is always kept constant. There is a need to. In the case of strip-shaped base materials such as film and aluminum, the thickness variation is minimal, so even if the gap is adjusted to the optimum conditions and coating is then performed with the die body position fixed, the gap remains almost constant. Kept in.

However, in the case of galvanized steel sheet, J
IS standard G3302 plate thickness tolerance (for example, plate thickness 0.6
In the case of mm, ± 60 μm) may exceed the appropriate gap for die coating (20 to 80 μm). Therefore, if the die body is fixed and coated, the gap will change greatly, and the galvanized steel sheet will have a die tip lip portion. May come into contact with and be damaged. In particular, the optimum gap when applying a single layer of primer coating or when applying two layers is 10 to 30 μm.
However, it was impossible to fix the die body and apply it to the galvanized steel sheet.

Therefore, in order to enable die coating on a galvanized steel sheet, the applicant of the present application has proposed a nip roll type die coater 41 shown in FIG. 3 in Japanese Patent Application No. 6-193067. This nip roll type die coater 41
A support table 42, a nip roll 43, and a die body 44 are provided. The support base 42 is a strip-shaped base material W such as a galvanized steel plate.
With respect to the backup roll 100 that rotates while supporting, the linear roll 45 can be moved forward and backward in the horizontal direction. The nip roll 43 is a backup roll 10.
It is rotatably supported in parallel with 0 and on the side of the support base 42, and is urged to the strip-shaped substrate W by a cylinder rod 47 extending from an air cylinder 46.

The die body 44 is attached to the upper portion of the support base 42 via a die set base 48. The paint supplied from the paint supply source (not shown) to the die body 44 is discharged from the tip lip portion 44a toward the strip-shaped substrate W. The tip lip portion 44a is provided on the nip roll 43 with respect to the horizontal line X passing through the central axis 101 of the backup roll 100.
And a position on the strip-shaped substrate W that is symmetrical with the contact point with and are opposed to each other with a predetermined gap.

In the nip roll type die coater 41 having the above-mentioned structure, the nip roll 43 and the support base 42 advance and retreat with respect to the backup roll 100 according to the variation in the plate thickness of the strip-shaped substrate W. At the same time, the die body 44 also advances and retracts by the same amount, and the gap between the tip lip portion 44a and the strip-shaped substrate W is maintained substantially constant in the initial setting state regardless of the variation in the plate thickness of the substrate W. As a result, it becomes possible to apply a die coater even to a galvanized steel sheet having a thickness variation of about several tens of μm.

[0007]

In the nip roll type die coater 41, the nip roll 43 and the die body 44 are used.
By moving the support table 42 provided with the above-mentioned structure forward and backward with respect to the backup roll 100, it is possible to cope with the plate thickness variation of the strip-shaped substrate W.

However, there are various thicknesses of the galvanized steel sheet for precoating within the range of 0.27 to 1.2 mm. As shown in FIGS. 4 (a) and 4 (b), when the thickness of the substrate W to be applied next changes significantly from the previous one, the upper lip portion 44a of the tip lip portion 44a retracted in the horizontal direction H is drawn.
b, the gaps g ₁ and g ₂ for the lower lip portion 44c are different. In the multi-layer coating die, the length 1 of the tip lip portion 44a is longer than that of the single layer, so that the difference between the gaps g ₁ and g ₂ is further increased. In particular, the smaller the backup roll diameter, the more the nip roll 4
The larger the mounting angle θ of 3 and the die main body 44 with respect to the horizontal line X, the larger the gap difference. The optimum gap when applying a thin film is as small as about 10 to 20 μm. Since such a gap difference hinders stable application, it is necessary to readjust the gap. Therefore, there is a problem that it takes time and labor to change to a base material having a different plate thickness.

On the other hand, in the nip roll type die coater 50 shown in FIG. 5, the backup roll 100 and the guide roll 102 arranged in parallel with the backup roll 100 support the strip-shaped substrate W, and the nip roll 43 is positioned between the backup roll 100 and the guide roll 102. Holds the strip-shaped base material W. When the plate thickness of the strip-shaped substrate W changes, the nip roll 43 moves back and forth with respect to the guide roll 102 together with the support base 42. As a result, the support base 4
2 The die main body 44 fixed to the upper part moves back and forth with respect to the backup roll 100 on the horizontal line X.

According to the nip roll type die coater 50 described above, the die body 4 can be used regardless of the change in the plate thickness of the strip-shaped substrate W.
The gap g between the upper lip portion and the lower lip portion 4 can be kept constant. However, in addition to the need for another roll 102 in addition to the backup roll 100, the distance between the nip roll 43 and the die main body 44 becomes long, so that there is a drawback that delay in gap control followability becomes large. .

[0011]

SUMMARY OF THE INVENTION The present invention aims at providing a nip roll type die coater capable of solving the above-mentioned problems, with a predetermined gap provided on a belt-shaped substrate which is continuously conveyed while being supported by a backup roll. The opposing die body is provided so as to be able to advance and retreat in the radial direction toward the central axis of the backup roll, and a nip roll that can rotate while sandwiching the belt-like base material with the backup roll conveys the belt-like base material rather than the die body. In the upstream direction of the backup roll, it is urged in a radial direction toward the central axis of the backup roll, and the die body and the nip roll are connected by a follow-up moving mechanism, and the follow-up moving mechanism changes the plate thickness of the strip-shaped substrate. The die body is moved back and forth by the same amount as the movement amount of the nip roll that moves back and forth. Here, the plate thickness change of the strip-shaped base material includes both the plate thickness variation caused by the rolling unevenness and the change of the plate thickness due to the switching of the type of the strip-shaped base material.

In the follow-up movement mechanism, the incompressible fluid is sealed in a pair of cylinders with a diaphragm, which communicate with each other through the conduits, and the diaphragm of one cylinder is placed on the nip roll side and the diaphragm of the other cylinder. Can be connected to the die body side, respectively.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG.
The nip roll type die coater 1 according to the present invention includes a die body 2 on the upper portion thereof. The die main body 2 is placed on a die set table 3 having L-shaped side surfaces and extending in the coating width direction, and a tip lip portion 2 in which a paint discharge slot is opened.
a and a backup roll 100 that rotates in the direction of arrow a
And a strip-shaped substrate W that is continuously conveyed while being supported by the substrate 1 and is disposed to face each other with a slight gap g.

First, the support structure on one end side of the die set table 3 will be described below. A saddle metal fitting 4 is fixed to the lower part of the die set base 3, and an inclined surface 5 formed on the support base 5.
It can slide on a with almost no resistance. Further, when the saddle metal fitting 4 slides along the inclined surface 5a, the die body 2 moves to the central axis 1 of the backup roll 100.
It moves back and forth with respect to the backup roll 100 in the radial direction toward 01. In FIG. 1, this straight line in the radial direction is indicated by Y, and the straight line Y is the central axis 10 of the backup roll 100.
An angle θ _{1 is formed} with respect to the horizontal line X passing through 1.

A pulley 6 is rotatably supported on the upper portion of the support 5, and one end of a wire 7 hung on the pulley 6 is connected to a saddle member 4 and the other end is connected to a balance weight 8. The support base 5 is also provided with two linear way bearings 20 and 20 on the bottom thereof, and is horizontally movable on a rail 22 provided on a base base 21.
Further, the support base 5 is connected to an air cylinder 24 via a cylinder rod 23 fixed to the lower portion of the side surface. The air cylinder 24 is an actuator for receiving the base material plate joint signal and the abnormal signal from the previous process and retracting the support base 5 to avoid a collision of the plate joint portion or the like with the tip lip portion 2a of the die body 2. Therefore, after passing through the plate joint, the support base 5 is advanced to a predetermined position where it abuts on the stopper 25 provided on the front part of the base base 21. The air cylinder 24 is fixed on the base 21 by a holder 26.

A nip roll 10 extending parallel to the backup roll 100 is provided on the upstream side of the die body 2 in the conveyance direction of the strip-shaped substrate W. Nip roll 10
The rotary shaft 11 extends through a U-shaped groove 5b formed in the support base 5, and its tip end is rotatably supported by a movable bearing 12. The movable bearing 12 is fitted inside a U-shaped slide base 13 fixed to the side surface of the support 5. In this state, the movable bearing 12 can be moved back and forth with little resistance in the radial direction toward the central axis 101 of the backup roll 100. In FIG. 1, this straight line in the radial direction is indicated by Z. The straight line Z passes through the contact point between the nip roll 10 and the strip-shaped substrate W, and
An angle θ ₂ is formed with respect to the horizontal line X. Note that the angle θ
₂ may be the same angle as the angle θ ₁ formed by the straight line Y and the horizontal line X, or may be different.

Backup roll 100 for movable bearing 12
A rod 15 extending on a straight line Z through a through hole formed in the slide base 13 is fixed to the side surface on the side. A male screw is formed on the tip side of the rod 15, a nut 16 with a washer is screwed, and a compression coil spring 17 is externally mounted between the washer and the slide base 13. As a result, the nip roll 10 is urged against the strip-shaped substrate W by the restoring force of the compression coil spring 17. Here, instead of the compression coil spring 15, a disc spring may be used.

The die body 2 and the nip roll 10 are interlocked by a follow-up moving mechanism. The follow-up movement mechanism is composed of a pair of cylinders 28 and 29 with a diaphragm that communicate with each other via a conduit 27. Each cylinder 2
As shown in FIG. 2, 8 and 29 have a columnar shape, and are attached to the side surfaces of the support base 5 via brackets 30 and 31 (in FIG. 2, the cylinders 28 and 29 are arranged on both left and right sides for easy understanding). Separately.).

As shown in FIG. 1, each cylinder 28, 29
Have basically the same structure and the same size.
That is, the cylinders 28 and 29 have the same bore diameter, one wall thereof is formed of the diaphragm plates 32 and 33 of the same material and thickness, respectively, and the inside thereof is in a liquid-tight state. On the other hand, a different point is that the cylinder 28 is provided with an air bleeding port 34 and a valve 35, and the cylinder 29 is connected to another conduit 38 having an inlet 36 and an opening / closing valve 37 at the upper part. The central portion of the diaphragm plate 32 of the cylinder 28 and the movable bearing 12 on the nip roll 10 side are operated by the operating rod 39, and the central portion of the diaphragm plate 33 of the cylinder 29 and the saddle metal member 4 on the die body 2 side are operated by the operating rod 40. Are linked by.

As will be described later, since it is necessary to accurately transmit the minute movement amount of the nip roll 10 to the die main body 2, the movable bearing 12 and the slide base 13, and the inclined surface 5a of the saddle metal member 4 and the support base 5 are connected. It is preferable to use a needle bearing having a small actuation resistance for the sliding portion between them. For the same reason, each cylinder 28,
The mounting angle of 29 is such that the central axis 28a of the cylinder 28 coincides with the straight line Z and the central axis 29a of the cylinder 29 is 29a.
Is preferably parallel to the straight line Y.

The structure described above is similarly provided on the other end side of the die set table 3. Next, the adjustment and coating operation of the nip roll type die coater 1 having the above structure will be described. First, the nut 16 with a washer is rotated to bias the nip roller 10 toward the backup roll 100 in a state where the belt-shaped substrate W is not present on the backup roll 100. At this time, the restoring force of the compression coil spring 17 is equal to or more than the diagonal downward component force of the gravity load of the nip roll 10 and the movable bearing 12, and the diaphragm plate 3 of the cylinder 28.
2 is initialized to the maximum outward convex state. In this state, the strip-shaped base material W is wound around the backup roll 100,
It is held between the nip roll 10. The plate thickness of the galvanized steel sheet for precoating as the strip-shaped substrate W is 0.27 to
Although there are various types within the range of 1.2 mm, the diaphragm plate 32 is always in a convex state regardless of the plate thickness, and the straight line Z
A displacement amount of 0.93 mm or more, which corresponds to the maximum plate thickness difference, can be taken in the direction along.

After that, the air bleeding valve 35 and the opening / closing valve 37 of the cylinder 28 are opened, and the incompressible fluid is flown in through the inlet 36. Mercury, hydraulic oil, etc. are preferably used for this incompressible fluid. The inside of the cylinder 28 is filled with an incompressible fluid to completely discharge the air, and then the valve 35 is closed. Then, the injection is continued until the conduit 27 communicating with the cylinder 28, the cylinder 29, the conduit 38 and the injection port 36 are filled with the incompressible fluid.

Then, gap adjustment is performed on the die body 2. First, the weight of the balance weight 8 is adjusted with the tip lip portion 2a of the die body 2 in contact with the strip-shaped substrate W. Specifically, when the strip-shaped base material W is continuously applied, the coating bead formed between the tip lip portion 2a and the surface of the base material maintains a constant pressure which is a stable application state, and this pressure is applied to the tip lip portion. It acts on 2a as a reaction force.
Therefore, in the weight adjustment of the balance weight 8, the diagonal downward component force of the gravity load of the die main body 2, the die set table 3, the saddle metal fitting 4, etc. is reduced, while the adjusted gap is changed by the reaction force from the paint bead. Therefore, the pressing force of the tip lip portion 2a against the strip-shaped substrate W is set to be larger than the pressure of the paint beat.

At this time, the diaphragm plate 33 of the cylinder 29 is concave as seen from the outside, and as in the case of the cylinder 28 described above, the diaphragm plate 33 is always 0.93 mm in the direction along the straight line Y while keeping the concave state. The above displacement is possible.

After adjusting the balance weight 8, the on-off valve 37
Closed to enclose incompressible fluid. Then, the die body 2 is retracted by a gap adjusting mechanism (not shown) provided on the die set table 3, and the gap g between the tip lip portion 2a and the strip-shaped substrate W is initially set to the optimum gap. At this time, the positions of the die set table 3 and the saddle hardware 4 on the inclined surface 5a are
The incompressible fluid is prevented from moving by the sealed cylinder 29.

After the above adjustments are made, the coating material is supplied to the die body 2 from a coating material supply source (not shown), and the strip-shaped substrate W is run to perform continuous coating. The nip roll 10 holds the strip-shaped base material W between the backup roll 100 and rotates in the direction of the broken line arrow b.

The allowable thickness of the galvanized steel sheet based on the JIS standard varies depending on the sheet thickness, but the variation in sheet thickness due to uneven rolling is usually several tens of μm in the running direction or the coating width direction. When such a plate thickness variation portion comes into contact with the nip roll 10, the nip roll 10 moves back and forth on the straight line Z according to the plate thickness variation. This forward / backward movement amount is determined by the movable bearing 12
And transmitted to the cylinder 28 via the operating rod 39,
The inner volume changes due to the deformation of the diaphragm plate 32. Main bodies of cylinders 28 and 29 and conduits 27 and 3
8 itself is formed so as not to cause distortion, the volume of the incompressible fluid is invariable, and the cylinders 28 and 29 are of the same size. Therefore, an increase / decrease in the internal volume of the cylinder 28 appears as an increase / decrease in the internal volume of the cylinder 29, and the diaphragm plate 33 is deformed in the direction along the central axis 29a by the same amount as the deformation amount of the diaphragm plate 32. As a result, the operating rod 40, the saddle metal fitting 4, and the die set base 3 move, and the die body 2 moves back and forth with respect to the belt-shaped substrate W on the straight line Y. As a result, the gap g is kept almost in the initial setting state regardless of the variation in the plate thickness of the strip-shaped substrate W, and stable coating is possible.

Further, since the follow-up moving mechanism composed of the cylinders 28, 29 and the like are independently provided on both sides in the coating width direction, the nip roll 10 causes the backup roll 100 to move due to the plate thickness variation of the strip-shaped substrate W in the coating width direction. When slightly tilted, the die body 2 is also driven so as to tilt.

Further, even when the plate thickness is changed by switching the strip-shaped substrate W, the die body 2 is changed according to the change amount of the plate thickness.
Moves forward and backward in the radial direction toward the central axis 101 of the backup roll 100, so that the gap between the upper lip portion and the lower lip portion of the tip lip portion 2a is kept equal. Therefore, the coating operation can be continued without re-adjusting the gap.

As a follow-up moving mechanism that follows the minute movement of the nip roll 10 to follow the die main body 2, a method of transmitting the moving amount by a link mechanism can be considered, but in order to accurately transmit the minute moving amount, the axial clearance of the link is transmitted. Needs to be manufactured to about several μm, which is technically and costly difficult. In addition, as an electrical follow-up mechanism, the nip roll 10
A method of electrically detecting the amount of movement of the die and driving the driving device based on the signal to move the die main body 2 back and forth is conceivable. However, the control device for minute movement is expensive and complicated to control. It has a drawback that it takes a long time to respond and a delay in gap control is likely to occur.

[0031]

As is apparent from the above description, in the nip roll type die coater according to the present invention, the nip roll moves forward and backward in the radial direction toward the central axis of the backup roll in accordance with the change in the plate thickness of the strip-shaped substrate. The movement amount of the nip roll is transmitted to the die body via the follow-up movement mechanism, and the die body moves in the radial direction toward the central axis of the backup roll by the same amount as the forward / backward movement amount of the nip roll.

Therefore, according to the present invention, the gap between the die body and the surface of the base material can be controlled within the optimum gap range capable of stable coating regardless of the change in the plate thickness of the strip-shaped base material, and the coating defects Occurrence is low. Further, even when the plate thickness of the coating base material is changed, labor for resetting the gap can be saved, and labor can be saved and operating time can be shortened. Furthermore, since the die body and nip roll are movable in different radial directions, the layout of the die body and nip roll can be determined independently without being restricted by the backup roll diameter or the mounting angle of the backup roll. , The degree of freedom in design is increased.

Further, according to the nip roll type die coater using the incompressible fluid in the follow-up movement mechanism, the minute movement of the nip roll can be accurately transmitted with a simple and inexpensive structure, and the die body can be driven with good response. it can.

[Brief description of the drawings]

FIG. 1 is a side view including a partial cross section of a nip roll type die coater according to the present invention.

FIG. 2 is a diagram illustrating a mounted state of a cylinder with a diaphragm.

FIG. 3 is a schematic view of a nip roll type die coater according to another application of the present applicant.

FIG. 4 is an enlarged view of the vicinity of the tip lip portion of the multilayer die body in the nip roller type die coater of FIG.
Shows an initial setting state in which the gaps of the upper lip portion and the lower lip portion are equal, and (b) shows a state in which there is a difference in the gaps of the upper lip portion and the lower lip portion when the substrate plate thickness changes significantly. Indicates.

FIG. 5 is a schematic view of a nip roll type die coater in which a belt-shaped substrate is supported by two rollers.

[Explanation of symbols]

1 ... Nip roll type die coater, 2 ... Die body, 10 ...
Nip roll, 27 ... Conduit, 28, 29 ... Cylinder with diaphragm, 32, 33 ... Diaphragm plate (diaphragm), 100 ... Backup roll, 101 ... Central axis,
W ... Strip-shaped substrate.

Claims (2)

[Claims] 1. A die main body, which is supported by a backup roll and is continuously conveyed, faces a strip-shaped base material with a predetermined gap therebetween and is capable of advancing and retracting in a radial direction toward a central axis of the backup roll, and the backup roll. The nip roll that is rotatable while holding the strip-shaped base material between is urged in a state in which the nip roll can be moved forward and backward in the radial direction toward the central axis of the backup roll upstream of the die body in the transfer direction of the strip-shaped base material. A nip roll type die coater in which the main body and the nip roll are connected by a follow-up movement mechanism, and the follow-up movement mechanism moves the die body forward and backward by the same amount as the movement amount of the nip roll that moves forward and backward with the change in the plate thickness of the strip-shaped substrate. . 2. A non-compressible fluid is sealed in a pair of cylinders with a diaphragm, which communicate with the inside of each cylinder via a conduit, and the diaphragm of one cylinder is connected to the nip roll side and the diaphragm of the other cylinder is connected to the die body side. The nip roll type die coater according to claim 1, further comprising a follow-up movement mechanism having the above-mentioned configuration.