JP2021126616A - Doctor chamber coater and method for manufacturing coated object using the same - Google Patents

Abstract

To provide a doctor chamber coater that can suppress an amount of coating liquid drooping from a second roll body during a standby mode, and to provide a method for manufacturing a coated object using the same.SOLUTION: A doctor chamber coater 1 applies a coating liquid 2 to an object to be coated 3. The doctor chamber coater includes: a doctor chamber 4 reserving the coating liquid 2 therein; a first roll body 5 disposed so that the coating liquid 2 reserved in the doctor chamber 4 adheres to the outer peripheral surface thereof; a second roll body 6 to which the coating liquid 2 adhering to the outer peripheral surface of the first roll body 5 is transferred; and a third roll body 7 for holding an object to be coated between the third roll body and the second roll body 6. When an operation mode of the doctor chamber coater 1 is switched to a standby mode from a coating mode, a nip pressure between the first and second roll bodies 5, 6 is decreased.SELECTED DRAWING: Figure 2

Description

The present invention relates to a doctor chamber coater for applying a coating liquid to an object to be coated, and a method for producing a coated object using the doctor chamber coater.

Examples of this type of doctor chamber coater that has been conventionally used include the configurations shown in Patent Document 1 and the like below. That is, in the conventional configuration, the doctor chamber having an opening, the first roll body arranged so that the coating liquid in the doctor chamber adheres to the outer peripheral surface, and the coating adhered to the outer peripheral surface of the first roll body. A second roll body to which the work liquid is transferred and a third roll body in which the object to be coated is sandwiched between the second roll bodies are provided.

Japanese Unexamined Patent Publication No. 2019-155311 Japanese Unexamined Patent Publication No. 2018-051482

The operation mode of the doctor chamber coater as described above includes a coating mode and a standby mode. The coating mode is an operation mode in which the object to be coated is sandwiched between the second roll body and the third roll body, and the coating liquid is transferred to the object to be coated. The standby mode is an operation mode in which the second roll body and the third roll body are separated from each other, and the coating liquid is circulated between the doctor chamber, the first roll body, and the second roll body.

When a coating liquid having a relatively low viscosity was used, the coating liquid drips from the second roll body during the standby mode. For example, in the case of a coater using a paint pan as shown in Patent Document 2 and the like, the coating liquid dripping from the second roll body (applicator roll) only returns to the paint pan, which does not pose a big problem. However, in the case of a coater using a doctor chamber, if a large amount of coating liquid drips from the second roll body, it is necessary to add a saucer corresponding to a paint pan or perform regular cleaning work, so that the coated product needs to be cleaned. It becomes a factor to increase the production cost.

The present invention has been made to solve the above problems, and an object of the present invention is to use a doctor chamber coater capable of suppressing the amount of coating liquid dripping from the second roll body during the standby mode and a doctor chamber coater thereof. It is to provide a method for manufacturing a coated product.

The doctor chamber coater according to the present invention is a doctor chamber coater that applies a coating liquid to an object to be coated, and is a doctor chamber in which the coating liquid is stored inside and a coating in the doctor chamber on the outer peripheral surface. The object to be coated is between the first roll body arranged so that the liquid adheres, the second roll body to which the coating liquid adhering to the outer peripheral surface of the first roll body is transferred, and the second roll body. In the operation mode of the doctor chamber coater, the object to be coated is sandwiched between the second roll body and the third roll body, and the coating liquid is transferred to the object to be coated. It includes a coating mode and a standby mode in which the second roll body and the third roll body are separated from each other and the coating liquid is circulated between the doctor chamber, the first roll body and the second roll body. When the mode is switched from the coating mode to the standby mode, the nip pressure between the first and second roll bodies is reduced.

In addition, the method for producing a coated object according to the present invention includes a step of applying a coating to the object to be coated by using the above-mentioned doctor chamber coater.

According to the doctor chamber coater of the present invention and the coating material manufacturing method using the same, when the operation mode is switched from the coating mode to the standby mode, the nip pressure between the first and second roll bodies is reduced. It is possible to suppress the amount of the coating liquid dripping from the second roll body during the standby mode.

It is a top view which shows the doctor chamber coater according to Embodiment 1 of this invention. It is sectional drawing which follows the line II-II of FIG. It is a front view which shows the doctor chamber of FIG. It is explanatory drawing which shows the state which the 1st and 2nd division body were rotated so that the opening of FIG. 2 is widened. It is explanatory drawing which shows the state which the 1st and 2nd division body of FIG. 4 were rotated. It is explanatory drawing which shows the state which the doctor chamber and the 1st roll body of FIG. 2 are rotated about the rotation axis of the 2nd roll body. It is explanatory drawing which shows the modification which the transport direction of the object to be coated is changed to the horizontal direction of FIG. It is explanatory drawing which shows the state which the operation mode of the doctor chamber coater of FIG. 2 is set to the standby mode. It is explanatory drawing which shows the nip pressure control mechanism of the 1st and 2nd roll body. It is explanatory drawing which shows the doctor chamber coater according to Embodiment 2 of this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to each embodiment, and the components can be modified and embodied without departing from the gist thereof. In addition, various inventions can be formed by appropriately combining the plurality of components disclosed in each embodiment. For example, some components may be removed from all the components shown in the embodiments. Furthermore, the components of different embodiments may be combined as appropriate.

Embodiment 1.
1 is a plan view showing the doctor chamber coater 1 according to the first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1, and FIG. 3 shows the doctor chamber 4 of FIG. It is a front view.

The doctor chamber coater 1 shown in FIG. 1 is a facility for applying the coating liquid 2 to the object to be coated 3. Examples of the coating liquid 2 include ink, paint, chemical conversion treatment liquid, and the like. The coating liquid 2 can contain an insoluble matter. The insoluble matter is, for example, a pigment or an aggregate, which is dispersed without being dissolved in water or a solvent. Examples of the object to be coated 3 include a strip-shaped member made of a material such as paper, plastic, or metal. The metal strip-shaped member includes a cold-rolled steel plate, various plated steel plates, an aluminum alloy plate, a titanium plate, and a stainless steel plate.

As shown in FIGS. 1 to 3, the doctor chamber coater 1 includes a doctor chamber 4, a first roll body 5, a second roll body 6, and a third roll body 7.

The doctor chamber 4 is a container body having a liquid storage space 4a (see FIG. 2) for storing the coating liquid 2 inside. The front portion of the doctor chamber 4 is provided with an opening 4b that communicates the inside and outside of the liquid storage space 4a.

The first roll body 5 is a columnar member provided so as to be rotatable. The first roll body 5 can be rotationally driven by a driving force of a driving device (not shown). The first roll body 5 is arranged so that the coating liquid 2 in the doctor chamber 4 adheres to the outer peripheral surface. The first roll body 5 of the present embodiment is arranged inside the liquid storage space 4a (doctor chamber 4) so that the outer peripheral surface faces the outside of the doctor chamber 4 through the opening 4b. That is, most of the outer peripheral surface of the first roll body 5 is arranged in the doctor chamber 4 with respect to the circumferential direction of the first roll body 5. In other words, most of the outer peripheral surface of the first roll body 5 is surrounded by the doctor chamber 4.

The second roll body 6 is a columnar member provided so as to be rotatable. The second roll body 6 can be rotationally driven by a driving force of a driving device (not shown). The second roll body 6 is arranged outside the liquid storage space 4a (doctor chamber 4) so that the outer peripheral surface is in contact with the outer peripheral surface of the first roll body 5.

The third roll body 7 is a columnar member rotatably provided, and is arranged so as to sandwich the object to be coated 3 with the second roll body 6. In the doctor chamber coater 1 of the present embodiment, the third roll body 7 is arranged on the side of the second roll body 6 in the horizontal direction, and the object to be coated 3 is conveyed from the lower side to the upper side in the vertical direction. Will be done. In FIG. 2, the second roll body 6 is rotated counterclockwise and the third roll body 7 is rotated clockwise in accordance with the transport direction of the object to be coated 3.

When the coating liquid 2 is stored in the liquid storage space 4a in the doctor chamber 4, the coating liquid 2 is sequentially adhered to the outer peripheral surface of the first roll body 5 by rotating the first roll body 5. The coating liquid 2 adhering to the outer peripheral surface of the first roll body 5 is transferred to the outer peripheral surface of the second roll body 6 and then transferred to the object to be coated 3. The third roll body 7 supports the object to be coated 3 when the coating liquid 2 is transferred from the second roll body 6 to the object to be coated 3. The first roll body 5 may be referred to as a gravure roll, the second roll body 6 may be referred to as an applicator roll, and the third roll body 7 may be referred to as a backup roll.

The coating method includes reverse coating and natural coating. The reverse coating is a method in which the coating is performed while rotating the second roll body 6 so as to oppose the transport direction of the object to be coated 3. In the reverse coating, in FIG. 2, the first roll body 5 is rotated counterclockwise, the second roll body 6 is rotated clockwise, and the third roll body 7 is rotated clockwise. The natural coating is a method in which the coating is performed while rotating the second roll body 6 so as to follow the transport direction of the object to be coated 3. In the natural coating, in FIG. 2, the first roll body 5 is rotated clockwise, the second roll body 6 is rotated counterclockwise, and the third roll body 7 is rotated clockwise.

When the object to be coated 3 is a metal material such as a steel plate, deformation such as center elongation in the center of the plate, ear elongation at the edge of the plate, and / or quarter elongation between them occurs in the object to be coated 3. There are times when. When coating a plate (coil) having a bad plate shape (large deformation has occurred), the third roll body 7 forcibly controls the nip pressure, so that the second roll body 6 to the object to be coated 3 are coated. The coating liquid 2 can be uniformly transferred to the coating liquid 2. On the other hand, in the case of a plate having a good plate shape, the third roll body 7 is not niped, and the tensioned object 3 to be coated is pressed against the second roll body 6 for coating (no backing coating). good.

Here, assuming that the first roll body 5 is arranged outside the liquid storage space 4a, the coating liquid 2 is concentrated due to the vaporization of water or the solvent on the outer peripheral surface of the first roll body 5. As a result, the composition of the coating liquid 2 may fluctuate. In the doctor chamber coater 1 of the present embodiment, since the first roll body 5 is arranged inside the liquid storage space 4a, the concentration of the coating liquid 2 on the outer peripheral surface of the first roll body 5 is suppressed. It is possible to reduce the composition fluctuation of the coating liquid 2. Further, it is possible to reduce the possibility that foreign matter such as dust adheres to the first roll body 5 and is mixed in the coating liquid 2.

Hereinafter, each configuration of the doctor chamber coater 1 will be described in more detail with reference to FIGS. 4 to 7 in addition to FIGS. 1 to 3 described above. FIG. 4 is an explanatory view showing a state in which the first and second divided bodies 411 and 412 are rotated so as to widen the opening 4b of FIG. 2, and FIG. 5 is an explanatory view showing a state in which the first and second divided bodies 411 and 412 of FIG. , 412 are explanatory views showing the rotated state, and FIG. 6 is an explanatory view showing a state in which the doctor chamber 4 and the first roll body 5 of FIG. 2 are rotated around the rotation axis of the second roll body 6. FIG. 7 is an explanatory view showing a modified example in which the transport direction of the object to be coated 3 of FIG. 6 is changed to the horizontal direction.

As particularly shown in FIG. 2, the doctor chamber 4 has an inner wall 40 that partitions the liquid storage space 4a. The shape of the inner wall 40 is arbitrary, but the inner wall 40 of the present embodiment includes a lower curved surface 40a, a lower connecting wall 40b, a back wall 40c, an upper curved surface 40d, and an upper connecting wall 40e.

The lower curved surface 40a and the lower connecting wall 40b are arranged below the liquid storage space 4a. The lower curved surface 40a extends from the front end of the doctor chamber 4 toward the depth of the doctor chamber 4 in the depth direction 4d. The lower connecting wall 40b connects between the rear end of the lower curved surface 40a and the back wall 40c. The lower curved surface 40a and the lower connecting wall 40b are formed by the upper surface of the first divided body 411 described later.

The upper curved surface 40d and the upper connecting wall 40e are arranged above the liquid storage space 4a. The upper curved surface 40d extends from the front end of the doctor chamber 4 toward the depth of the doctor chamber 4 in the depth direction 4d. The upper connecting wall 40e connects between the rear end of the upper curved surface 40d and the back wall 40c. The upper curved surface 40d and the upper connecting wall 40e are composed of the lower surface of the second divided body 412, which will be described later.

The back wall 40c is an inner wall located at the back of the doctor chamber 4 in the depth direction 4d, and is arranged between the lower connecting wall 40b and the upper connecting wall 40e. The back wall 40c extends in the height direction 4h of the doctor chamber 4. The back wall 40c of the present embodiment is composed of an outer surface of a shaft portion 410, which will be described later.

In the present embodiment, the lower curved surface 40a and the upper curved surface 40d are formed by curved surfaces having a shape along the outer peripheral surface of the first roll body 5. The lower curved surface 40a and the upper curved surface 40d are composed of arcuate surfaces that form a part of a circle having a diameter larger than that of the first roll body 5. In the present embodiment, the distance between the lower curved surface 40a and the upper curved surface 40d and the outer peripheral surface of the first roll body 5 is constant in the circumferential direction of the first roll body 5.

As described above, the coating liquid 2 may contain an insoluble matter. The insoluble matter may settle in the liquid storage space 4a when the flow of the coating liquid 2 in the liquid storage space 4a is small, for example, when the rotation speed of the first roll body 5 is slow. When the insoluble matter is settled in the liquid reservoir space 4a, there is a possibility that an unintended pattern may be generated on the coated surface of the object to be coated. In the doctor chamber 4 of the present embodiment, the first roll body 5 is arranged inside the liquid storage space 4a (doctor chamber 4). Therefore, as compared with the embodiment in which the first roll body 5 is arranged outside the liquid storage space 4a, the rotation of the first roll body 5 can generate a larger flow of the coating liquid 2, and the first roll body 5 can flow. The coating liquid 2 can be more reliably agitated by the rotation of the roll body 5. That is, since the first roll body 5 is arranged inside the liquid storage space 4a, the sedimentation of the insoluble matter can be suppressed.

Since the lower curved surface 40a has a shape along the outer peripheral surface of the first roll body 5, the coating liquid 2 can be agitated more uniformly, and the sedimentation of the insoluble matter can be suppressed more reliably. Further, since the distance between the lower curved surface 40a and the outer peripheral surface of the first roll body 5 is constant in the circumferential direction of the first roll body 5, the coating liquid 2 can be stirred more uniformly, and the insoluble matter can be stirred. The sedimentation of the water can be suppressed more reliably. The distance between the lower curved surface 40a and the outer peripheral surface of the first roll body 5 is preferably 10 mm or less. This is to make it possible to more reliably suppress the sedimentation of insoluble matter between the lower curved surface 40a and the upper curved surface 40d and the outer peripheral surface of the first roll body 5. Further, since the upper curved surface 40d is configured in the same manner as the lower curved surface 40a described above, it is possible to cope with the case where the doctor chamber 4 is used by reversing the direction of the doctor chamber 4, for example, as in the aspect of FIG.

As particularly shown in FIGS. 1 and 3, the doctor chamber 4 of the present embodiment includes a chamber body 41, a pair of sealing members 42, a pair of side wall bodies 43, an upper doctor blade 44, a lower doctor blade 45, and a blade. It has an adjusting unit 46 (see FIG. 2).

The chamber body 41 is a portion arranged in the central portion of the doctor chamber 4 in the width direction 4w (axial direction of each roll body 5 to 7) of the doctor chamber 4. The chamber body 41 has an outer shape having a substantially C-shaped cross section. The chamber body 41 partitions the upper part and the lower part of the liquid storage space 4a. When the chamber body 41 is viewed alone, the side portion of the chamber body 41 is open.

Each seal member 42 is arranged on the side (both sides) of the chamber body 41 related to the width direction 4w of the doctor chamber 4, and partitions the side portion of the liquid storage space 4a. The surface of each seal member 42 constitutes a side surface for partitioning the side portion of the liquid storage space 4a. The first roll body 5 can extend to the outside of the liquid storage space 4a through a hole provided in the seal member 42.

Each side wall body 43 is arranged on the side (both sides) of the seal member 42 related to the width direction 4w of the doctor chamber 4, and sandwiches the seal member 42 with the chamber main body 41. The chamber body 41 is fastened to each other by, for example, a fastening member (not shown) such as a bolt while the seal member 42 is sandwiched between the side wall 43 and the chamber body 41. , The seal member 42 and the side wall 43 are integrated with each other. The first roll body 5 may extend outward of the doctor chamber 4 through a hole provided in the side wall body 43 or be pivotally supported by the side wall body 43.

As the chamber body 41 (particularly, the first and second divided bodies 411, 412 described later) and the side wall body 43, a metal member such as an aluminum alloy body can be used. As the sealing member 42, for example, a foam such as polyethylene can be used.

The chamber body 41 of the present embodiment is provided with a recess in which the seal member 42 is housed. By housing the seal member 42 in the recess, it is possible to prevent the seal member 42 from being excessively compressed between the chamber main body 41 and the side wall body 43. The recess may be provided in the side wall body 43.

The upper doctor blade 44 is a longitudinal member extending from the upper part of the chamber body 41 so that the tip thereof is abutted against the peripheral surface of the first roll body 5. Similarly, the lower doctor blade 45 is a longitudinal member extending from the lower part of the chamber body 41 so that the tip thereof is abutted against the peripheral surface of the first roll body 5. The opening 4b of the doctor chamber 4 can be defined by the gap between the tips of the upper doctor blade 44 and the lower doctor blade 45.

In FIG. 2, when the first roll body 5 is rotated counterclockwise, that is, when the first roll body 5 is rotated in the same direction as the second roll body 6, the lower doctor blade 45 is the first roll body 5. It constitutes a downstream blade located on the downstream side of the opening 4b in the direction of rotation. On the contrary, when the first roll body 5 is rotated clockwise in FIG. 2, that is, when the first roll body 5 is rotated in the opposite direction to the second roll body 6, the upper doctor blade 44 is downstream. Configure the side blades. Although not shown, a recess is formed on the peripheral surface of the first roll body 5. The downstream blade (lower doctor blade 45 or upper doctor blade 44) scrapes the coating liquid 2 adhering to the peripheral surface of the first roll body 5 so as to leave the coating liquid 2 in the recess. As a result, a certain amount of the coating liquid 2 remains on the peripheral surface of the first roll body 5.

The upper doctor blade 44 of the present embodiment is arranged downward so that the tip on the first roll body 5 side is located above the base end on the chamber body 41 side. Further, the angle θ in the doctor chamber 4 between the extending direction of the upper doctor blade 44 and the tangent line of the first roll body 5 is set to be less than 90 °. By setting this angle θ to less than 90 °, the force (doctor pressure) at which the tip of the upper doctor blade 44 is pressed against the peripheral surface of the first roll body 5 becomes larger, and the upper doctor blade 44 scratches the coating liquid 2. It is possible to take more reliably. The angle θ in the doctor chamber 4 between the extending direction of the upper doctor blade 44 and the tangent line of the first roll body 5 is preferably 40 ° or more and 60 ° or less, and 50 ° or more and 60 ° or less. Is more preferable.

Similarly, the lower doctor blade 45 of the present embodiment is arranged so as to be raised forward so that the tip on the first roll body 5 side is located above the base end on the chamber body 41 side. Further, the angle θ in the doctor chamber 4 between the extending direction of the lower doctor blade 45 and the tangent line of the first roll body 5 is set to be less than 90 °. By setting this angle θ to less than 90 °, the force (doctor pressure) at which the tip of the lower doctor blade 45 is pressed against the peripheral surface of the first roll body 5 becomes larger, and the lower doctor blade 45 scratches the coating liquid 2. It is possible to take more reliably. The angle θ in the doctor chamber 4 between the extending direction of the lower doctor blade 45 and the tangent line of the first roll body 5 is preferably 40 ° or more and 60 ° or less, and 50 ° or more and 60 ° or less. Is more preferable.

The blade adjusting portion 46 is configured to adjust the angle θ between the extending direction of the upper doctor blade 44 and the lower doctor blade 45 and the tangent line of the first roll body 5. The blade adjusting portion 46 of the present embodiment is configured so that the angle θ can be adjusted by adjusting the separation distance between the rear end portions of the upper doctor blade 44 and the lower doctor blade 45 and the chamber main body 41. There is. More specifically, the blade adjusting portion 46 of the present embodiment is a member having a non-circular cross section arranged between the chamber main body 41 and the upper doctor blade 44 and the lower doctor blade 45, and the blade adjustment is performed. The angle θ is adjusted by rotating the member constituting the portion 46. However, the configuration of the blade adjusting portion 46 is arbitrary, for example, a bolt inserted into the rear end portion of the upper doctor blade 44 and the lower doctor blade 45 and the chamber body 41, or after the upper doctor blade 44 and the lower doctor blade 45. The blade adjusting portion 46 may be formed by other members such as shims inserted between the end portion and the chamber body 41. The upper doctor blade 44 and the lower doctor blade 45 may be held by a holder (not shown), and the angle θ may be adjusted by or together with the holder.

In the doctor chamber 4 of the present embodiment, the pipe body 47 is connected to the lower part of each side wall body 43. Inside each side wall body 43, a flow path 43a connecting the pipe body 47 and the liquid storage space 4a is provided. The seal member 42 is provided with an opening 42a located below the liquid storage space 4a while communicating with the flow path 43a and the liquid storage space 4a of the side wall body 43. That is, in the present embodiment, the opening 42a is provided on the side surface of the liquid storage space 4a. In the doctor chamber 4 of the present embodiment, the coating liquid 2 is supplied to the liquid reservoir space 4a through the opening 42a at the lower end side related to the width direction 4w, and through the opening 42a at the lower end side related to the width direction 4w. The coating liquid 2 is discharged from the liquid reservoir space 4a. The opening 42a at the lower end on one end side constitutes a supply port, and the opening 42a at the lower end on the other end side constitutes a discharge port. The orientation of the coating liquid 2 may be opposite to the orientation shown in FIGS. 1 to 3.

The coating liquid 2 is supplied to the liquid storage space 4a and the coating liquid 2 is discharged from the liquid storage space 4a by a supply device (not shown). The supply device is connected to each opening 42a via a pipe body 47 below each side wall body 43. Without limitation, the supply device can consist of a tank and a pump. The coating liquid 2 is stored in the tank. The pump supplies the coating liquid 2 in the tank to the liquid storage space 4a (doctor chamber 4). The coating liquid 2 supplied to the liquid storage space 4a is returned to the tank from the liquid storage space 4a. That is, the coating liquid 2 can be circulated between the tank and the liquid storage space 4a.

As described above, the coating liquid 2 is supplied to the liquid storage space 4a from the opening 42a (supply port) at the lower end side related to the width direction 4w, and the opening 42a (exhaust) at the lower end side related to the width direction 4w. By discharging the coating liquid 2 in the liquid storage space 4a from the outlet), the flow of the coating liquid 2 can be formed at the bottom of the liquid storage space 4a, and the sedimentation of the insoluble matter can be suppressed. The supply device is set so that the flow velocity of the coating liquid 2 along the width direction 4w (axial direction of each roll body 5 to 7) of the doctor chamber 4 at the bottom of the liquid reservoir space 4a is 0.1 m / s or more. It is preferable to supply 2. This is to more reliably suppress the sedimentation of insoluble matter.

The bottom portion of the liquid storage space 4a can be understood as, for example, the vicinity of the upper surface of the lower curved surface 40a. The flow velocity of the coating liquid 2 along the width direction 4w of the doctor chamber 4 at the bottom of the liquid reservoir space 4a can be obtained by the following method. That is, when the flow rate of the coating liquid 2 flowing from the opening 42a into the bottom of the liquid storage space 4a is A (L / s) and the area of the opening 42a is S (cm ² ), the coating liquid 2 in the opening 42a The flow velocity of is A / S × 0.01 (m / s). For example, when the opening 42a area S is 5 cm ² , when the coating liquid 2 having a flow rate of 1 L / s flows into the bottom of the liquid reservoir space 4a from the opening 42a, the flow velocity of the coating liquid 2 in the opening 42a is 2 m / s. Is.

The opening 42a may be arranged at a position away from the inner wall 40, but the opening 42a may be provided so that the lower edge of the opening 42a is at the same height as the inner wall 40. Although the opening 42a is shown to be rectangular in FIG. 2, it may be shaped along the inner wall 40. More specifically, the opening 42a has a base paper shape corresponding to the gap shape between the outer peripheral surface of the first roll body 5 and the lower curved surface 40a (the shape of the base paper portion of the fan or the fan shape in which the inner diameter side is missing). May be. For example, the shape of the opening 42a may be at least an arc shape at the lower edge of the opening 42a, such as a shape obtained by cutting a circle with a straight line parallel to the diameter.

As particularly shown in FIG. 2, the chamber body 41 has a shaft portion 410, a first divided body 411, a second divided body 412, and a plurality of cleaning nozzles 413.

The shaft portion 410 is arranged at the central portion of the doctor chamber 4 in the height direction 4h. Further, the shaft portion 410 is arranged at the rear portion (opposite side of the opening 4b) of the doctor chamber 4 in the depth direction 4d.

The first divided body 411 is arranged at the lower part of the doctor chamber 4 in the height direction 4h. The second divided body 412 is arranged in the upper part of the doctor chamber 4 in the height direction 4h. The first and second divided bodies 411 and 412 of the present embodiment have shapes that are vertically symmetrical with each other.

The first and second divided bodies 411 and 412 are integrally provided with each other via the shaft portion 410. Further, the first and second divided bodies 411 and 412 are provided so as to be rotatable around the shaft portion 410. The first and second divided bodies 411 and 412 are provided so as to be rotatable in opposite directions and the same directions.

The opening 4b can be narrowed by rotating the first and second divided bodies 411 and 412 in opposite directions with respect to the shaft portion 410. By narrowing the opening 4b, the tips of the upper doctor blade 44 and the lower doctor blade 45 can be brought into contact with the outer peripheral surface of the first roll body 5 even when the upper doctor blade 44 and the lower doctor blade 45 are worn.

As shown in FIG. 4, the opening 4b can be expanded by rotating the first and second divided bodies 411 and 412 in opposite directions with respect to the shaft portion 410. The doctor chamber 4 and the first roll body 5 are provided so as to be displaceable in a direction relatively close to each other and a direction away from each other along the depth direction 4d. As shown in FIG. 4, by expanding the opening 4b, the first roll body 5 can be taken in and out through the opening 4b. With such a configuration, maintenance of the doctor chamber 4 and the first roll body 5 can be performed more easily.

As shown in FIG. 5, the first and second divided bodies 411 and 412 can be rotated in the same direction with the opening 4b expanded. The aspect shown in FIG. 5 is an aspect in which the opening 4b is directed upward. By directing the opening 4b upward, maintenance of the inside of the doctor chamber 4 can be performed more easily.

Returning to FIG. 2, the cleaning nozzle 413 is a nozzle for spraying the cleaning liquid onto the inner wall 40 of the doctor chamber 4 and the first roll body 5. The cleaning nozzles 413 may be spaced apart from each other in the width direction 4w of the doctor chamber 4. After the coating liquid 2 is discharged from the liquid reservoir space 4a, the inner wall 40 and the first roll body 5 can be cleaned by spraying the cleaning liquid from the cleaning nozzle 413. For example, the flow path of the coating liquid 2 can be cleaned by passing the cleaning liquid from the cleaning nozzle 413 through the flow path of the coating liquid 2 such as the pipe body 47. Such cleaning can be performed when the coating liquid 2 is replaced.

In the present embodiment, the cleaning nozzles 413 are attached to the first and second divided bodies 411 and 412, respectively, and it is possible to spray the cleaning liquid on the inner wall 40 and the first roll body 5 from both the upper side and the lower side. Has been done. However, the arrangement of the cleaning nozzles 413 is arbitrary, and at least one of the upper and lower cleaning nozzles 413 may be omitted.

The first roll body 5 has a smaller diameter than the second roll body 6. By making the diameter of the first roll body 5 smaller, the doctor chamber 4 can be made smaller than the case where the diameter of the first roll body 5 is equal to or larger than the diameter of the second roll body 6. Further, the peripheral length of the first roll body 5 can be shortened, and the concentration of the coating liquid 2 in the first roll body 5 can be suppressed more reliably.

A liquid reservoir 2a of the coating liquid 2 is formed above the portion where the outer peripheral surfaces of the first and second roll bodies 5 and 6 come into contact with each other. The rotation shafts 5a and 6a of the first and second roll bodies 5 and 6 of the present embodiment are offset from each other in the vertical direction. That is, one of the rotation shafts 5a and 6a of the first and second roll bodies 5 and 6 is arranged at a higher position than the other. In the present embodiment, the rotation shaft 6a of the second roll body 6 is arranged at a position higher than the rotation shaft 5a of the first roll body 5. By offsetting the rotating shafts 5a and 6a in the vertical direction, it is possible to prevent the outer peripheral surfaces of the first and second roll bodies 5 and 6 from being in a line contact state at the lower part of the liquid reservoir 2a, and from the liquid reservoir 2a. Can suppress dripping. The rotation axes of the second and third roll bodies 6 and 7 of the present embodiment are arranged at the same height position.

The doctor chamber 4 and the first roll body 5 are individually provided so as to be movable in the horizontal direction. Further, the doctor chamber 4 and the first roll body 5 may be provided so as to be rotatable around the rotation shaft 6a of the second roll body 6. As shown in FIG. 6, the doctor chamber 4 and the first roll body 5 may be arranged so that the first roll body 5 is pressed against the second roll body 6 from diagonally below. The mode in which the first roll body 5 is pressed against the second roll body 6 from diagonally below is useful when the object to be coated 3 is transported in the horizontal direction as shown in FIG. 7. That is, it is possible to avoid interference between the object to be coated 3 transported in the horizontal direction and the doctor chamber 4.

Next, the operation mode of the doctor chamber coater 1 will be described with reference to FIGS. 2 and 8. FIG. 8 is an explanatory diagram showing a state in which the operation mode of the doctor chamber coater 1 of FIG. 2 is set to the standby mode.

The operation mode of the doctor chamber coater 1 of the present embodiment includes a coating mode and a standby mode.

In the coating mode, as shown in FIG. 2, the object to be coated 3 is sandwiched between the second and third roll bodies 6 and 7, and the coating liquid 2 adhered to the outer peripheral surface of the first roll body 5 in the liquid reservoir space 4a. Is transferred to the object to be coated 3 via the second roll body 6.

In the standby mode, as shown in FIG. 8, the second roll body 6 and the third roll body 7 are separated from each other, and the coating liquid 2 is applied between the liquid reservoir space 4a, the first roll body 5, and the second roll body 6. This is a circular mode. By circulating the coating liquid 2 between the liquid reservoir space 4a, the first roll body 5 and the second roll body 6, when the next material (the object to be coated 3 to be coated next) is introduced, You can start painting immediately.

Here, the amount of the coating liquid 2 transferred from the first roll body 5 to the second roll body 6 increases as the nip pressure (pressing pressure) between the first and second roll bodies 5 and 6 increases. If a large amount of the coating liquid 2 is transferred to the second roll body 6 during the standby mode, the coating liquid 2 may drip from the lower end of the second roll body 6. The dripping of the coating liquid 2 is more likely to occur in the coating liquid 2 having a low viscosity, for example, the viscosity of the # 4 Ford cup is about 15 seconds.

In the doctor chamber coater 1 of the present embodiment, when the operation mode is switched from the coating mode to the standby mode, the nip pressure between the first and second roll bodies 5 and 6 is reduced. That is, the nip pressure in the standby mode is lower than the nip pressure in the coating mode. By lowering the nip pressure in this way, it is possible to suppress the amount of the coating liquid 2 dripping from the second roll body 6 during the standby mode. The nip pressure in the standby mode can be 1/2 or less of the nip pressure in the coating mode. The dripping of the coating liquid 2 can be suppressed more reliably.

Here, FIG. 9 is an explanatory view showing the nip pressure control mechanism of the first and second roll bodies 5 and 6. The 1-1 and 1-2 actuators 53 and 54 are connected to both ends of the rotation shaft of the first roll body 5 via the 1-1 and 1-2 connecting bodies 51 and 52. The first-first and first-two connection bodies 51 and 52 can be pedestals that support the rotation shaft of the first roll body 5. The first roll body 5 is configured to be displaceable in the direction closer to and away from the second roll body 6 by the driving force of the first and second actuators 53 and 54. First and 1-2 load cells 55 and 56 are interposed between the actuators 53 and 54 and the connecting bodies 51 and 52, and are added to the first roll body 5 from the actuators 53 and 54. The load applied can be measured by each load cell 55, 56.

Similarly, the 2-1 and 2-2 actuators 63 and 64 are connected to both ends of the rotation shaft of the second roll body 6 via the 2-1 and 2-2 connecting bodies 61 and 62. ing. The 2-1 and 2-2 connecting bodies 61 and 62 can be a pedestal that supports the rotation axis of the second roll body 6. The second roll body 6 is configured to be displaceable in the direction of approaching and away from the first roll body 5 and / or the third roll body 7 by the driving force of the second 2-1 and 2-2 actuators 63 and 64. ing. 2-1 and 2-2 load cells 65 and 66 are interposed between the actuators 63 and 64 and the connecting bodies 61 and 62, and are added to the second roll body 6 from the actuators 63 and 64. The load applied can be measured by each load cell 65, 66.

The nip pressure between the first and second roll bodies 5 and 6 has a correlation with the measured values of the 1-1 and 1-2 load cells 55 and 56. The average value of the measured value of the 1-1 load cell 55 and the measured value of the 1-2 load cell 56 is called the first average load. For example, when the first average load in the coating mode is 200 kgf, it is preferable that the first average load in the standby mode is 100 kgf or less. As described above, this is to more reliably suppress the dripping of the coating liquid 2. Further, the first average load in the standby mode is more preferably 10 kgf or more. If the first average load is less than 10 kgf, the nip pressure between the first and second roll bodies 5 and 6 may become unstable.

The method for producing a coated object according to the present embodiment includes a step of applying a coating to the object to be coated 3 by using the above-mentioned doctor chamber coater 1.

According to such a doctor chamber coater 1 and a coating material manufacturing method using the same, when the operation mode is switched from the coating mode to the standby mode, the nip pressure between the first and second roll bodies 5 and 6 is increased. Since it can be lowered, the amount of the coating liquid 2 dripping from the second roll body 6 can be suppressed during the standby mode. As a result, it is possible to reduce the need for adding a saucer corresponding to a paint pan and performing regular cleaning work. This configuration is particularly useful when using a low viscosity coating liquid 2 with a # 4 Ford cup viscosity of 15 seconds or less.

Further, since the nip pressure between the first and second roll bodies 5 and 6 in the standby mode is 1/2 or less of the nip pressure in the coating mode, the surfaces of the first and second roll bodies 5 and 6 and the surface thereof and the same thereof. The amount of coating liquid dripping between rolls can be suppressed.

Further, since the rotation axes of the first and second roll bodies 5 and 6 are offset from each other in the vertical direction, the liquid formed above the points where the outer peripheral surfaces of the first and second roll bodies 5 and 6 come into contact with each other. It is possible to prevent the coating liquid from dripping from the reservoir 2a.

Embodiment 2.
FIG. 10 is an explanatory view showing the doctor chamber coater 1 according to the second embodiment of the present invention. In the first embodiment, it has been described that the first roll body 5 is arranged inside the liquid storage space 4a (doctor chamber 4). However, as shown in FIG. 10, the first roll body 5 may be arranged outside the liquid storage space 4a (doctor chamber 4). The first roll body 5 of the second embodiment is arranged so as to face the inside of the doctor chamber 4 (liquid storage space 4a) through the opening 4b.

Further, in the first embodiment, the chamber main body 41 is described as having the shaft portion 410, the first divided body 411, and the second divided body 412, but as shown in FIG. 10, the chamber main body 41 is formed by one block as a whole. It may be configured. Other configurations are the same as those in the first embodiment.

Even in the embodiment in which the first roll body 5 is arranged outside the liquid storage space 4a in this way, when the operation mode is switched from the coating mode to the standby mode, between the first and second roll bodies 5 and 6. By lowering the nip pressure, it is possible to suppress the amount of the coating liquid 2 dripping from the second roll body 6 during the standby mode.

1 Doctor chamber coater 2 Coating liquid 3 Material to be coated 4 Doctor chamber 5 1st roll body 6 2nd roll body 7 3rd roll body

Claims (5)

A doctor chamber coater that applies the coating liquid to the object to be coated.
The doctor chamber where the coating liquid is stored inside, and
A first roll body arranged so that the coating liquid in the doctor chamber adheres to the outer peripheral surface, and
The second roll body to which the coating liquid adhering to the outer peripheral surface of the first roll body is transferred, and
A third roll body that sandwiches the object to be coated is provided between the second roll body.
The operation mode of the doctor chamber coater is set to
A coating mode in which the object to be coated is sandwiched between the second roll body and the third roll body and the coating liquid is transferred to the object to be coated.
It includes a standby mode in which the second roll body and the third roll body are separated from each other and the coating liquid is circulated between the doctor chamber, the first roll body and the second roll body.
When the operation mode is switched from the coating mode to the standby mode, the nip pressure between the first and second roll bodies is reduced.
Doctor chamber coater. The nip pressure between the first and second roll bodies in the standby mode is ½ or less of the nip pressure in the coating mode.
The doctor chamber coater according to claim 1. The # 4 Ford cup viscosity of the coating liquid is 15 seconds or less.
The doctor chamber coater according to claim 1 or 2. The axes of rotation of the first and second rolls are offset from each other in the vertical direction.
The doctor chamber coater according to any one of claims 1 to 3. A step of applying a coating to the object to be coated by using the doctor chamber coater according to any one of claims 1 to 4.
Coating material manufacturing method.

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