JPH0574430B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coating device that uniformly applies coating materials such as high viscosity paints and adhesives to various substrates.

[Conventional technology]

Conventional coating equipment, such as a roll coater, is driven to rotate in the same direction as the conveyance direction of the substrate to be coated, and has a coating roll that applies paint etc. to the surface of the substrate, and a roller with a diameter larger than the coating roll in front of the coating roll. a doctor roll that has a small diameter, is rotated in a direction opposite to the rotational direction of the application roll at the contact portion with the application roll, and whose distance from the application roll can be adjusted;
It consists of a lower roll located below the application roll and driven to rotate in the same direction as the conveyance direction of the substrate to be coated. Then, the coating material applied to the coating roll surface was directly transferred and coated onto the surface of the substrate being conveyed while contacting the lower surface of the coating roll.

[Problem that the invention seeks to solve]

In the conventional coating apparatus as described above, continuous unevenness on the coating film surface in the same direction as the conveyance direction of the substrate, which is generally called roll tack, occurs. That is,
In the case of low-viscosity paints, the unevenness of the paint film disappears due to the natural flow of the paint transferred onto the substrate, creating a smooth surface, but in the case of high-viscosity paints, there are gaps between the application roll and the lower roll. Due to the generated waves, the unevenness of the painted surface remained as it was, and the surface smoothness was extremely low.

In addition, a linear sliding plate is provided on the top of the liquid delivery roll so as to be tangential to the roll, and the sliding plate scrapes the liquid that has flowed around the circumference of the delivery roll, and the liquid that has flowed down the sliding plate is removed. Coating devices for coating substrates are also known. (Refer to Patent Publication No. 1269547 of the Federal Republic of Germany) However, since a sliding plate is provided on the upper part of the roll in a tangentially inclined manner, resistance is created when the coating material flows down on the sliding plate, and it is difficult to prevent the coating material from flowing down on the sliding plate. The liquid scraped off by the sliding plate generates a force that pushes the liquid already on the sliding plate, which tends to cause waves in the coating film. In addition, in order to improve this problem, a sliding plate that is connected to the sliding plate that contacts in the tangential direction of the delivery roll and has a gentler slope than the slope of the tangential direction is provided, and a sliding plate that has a slope similar to the first tangential direction is provided. By providing a slope with a gentle slope at the center of the sliding plate that contacts the sliding plate, the flow rate of the liquid at that gentle part is slowed down, and then the slope is returned to its original level to reduce the flow of the coating material. A method to make the liquid film thickness uniform by increasing the speed is also described, but by making the slope gentler, it tends to cause waves in the liquid, and it is difficult to achieve a completely uniform thickness at the subsequent connection part. It was not possible to return it to a paint film, and there was still nothing satisfactory.

The present invention aims to solve the problems of such conventional coating apparatuses.

[Means for solving problems]

In order to solve the above-mentioned conventional problems, the present invention provides a coating blade 3 on the bottom surface of the coating roll 1, which has a vertical or nearly vertical angle so as to touch the coating roll 1 surface and its upper end. It is something.

[Effect]

By providing the coating blade 3 as described above, the present invention can apply high viscosity paint, adhesive, etc. to the base material 7.
It applies evenly and smoothly to the surface.

[Description of First Embodiment] A first embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

A coating roll 1 which is rotationally driven in a forward direction B with respect to a transport direction A of the substrate to be coated, and a coating roll 1 which is closer to the substrate carrying-in side of the coating roll 1 and whose diameter is smaller than that of the coating roll 1; A doctor roll 2 whose distance from the roll 1 is adjustable is provided.

The doctor roll 2 rotates in the opposite direction C to the rotational direction of the application roll 1 at the contact part with the application roll 1.
The distance between the coating roll 1 and the coating roll 1 is adjusted as appropriate depending on the thickness of the coating material to be coated on the substrate.

The application roll 1 and the doctor roll 2 stir the applied coating material between the rolls 1 and 2, respectively, so as to knead it.
A portion of it is adhered to the surface of the coating roll 1 with a uniform thickness through the adjusted gap between the rolls 1 and 2.

A coating blade 3 is provided at the bottom of the coating roll 1 so that the surface of the coating roll 1 and its upper end are in contact with each other. The applicator blade 3 has a length equal to the surface length of the applicator roll 1, is formed with an appropriate width, and has its lower end inclined vertically or at an arbitrary angle in the conveying direction or counter-conveying direction of the substrate 7. It may be provided.

Below the coating blade 3, there is a receiving gutter 4 for the coating material, and lower rolls 5, 5, which are located before and after the receiving gutter 4 and are driven to rotate in the forward direction D with respect to the conveying direction A of the substrate 7 to be coated. ' is provided.

The coating material adhered to the surface of the coating roll 1 with a uniform thickness is scraped off by the coating blade 3, and is also transmitted through the coating blade 3 surface, which is arranged perpendicularly or nearly perpendicularly to the surface of the coating roll. It flows down along the coating blade 3 due to its own weight, forms a continuous vertical curtain from the lower end of the coating blade 3, and flows down to the receiving gutter 4. Since this curtain-like flow flows vertically, it is formed by the weight of the coating material, and the amount of flow is constant as long as the specific gravity of the coating material does not fluctuate. In particular, in the case of high-viscosity coating materials, the viscosity causes the flow to flow in a curtain-like manner with a constant thickness without any turbulence.

The coating material flowing down into the receiving gutter 4 is put between the coating roll 1 and the doctor roll 2 using a circulation device (not shown), and is reused.

The substrate 7 conveyed by the conveyance device 6 passes through a curtain-shaped coating material with a uniform thickness flowing down from the coating blade 3 by the lower roll 5, so that a uniform smooth coating film is formed on the surface of the substrate 7. It is formed.

Furthermore, as shown in FIG. 3, a lower roll 5a is provided below the coating blade 3 without a receiving gutter, and a blade 8 for scraping the coating material is attached to the lower roll 5a, so that the curtain-shaped coating material can be directly removed. The coating material applied to the lower roll 5a may be scraped off with a scraping blade 8 and collected into a coating material collection gutter 9. E is the rotation direction of the lower roll 5a.

Furthermore, it goes without saying that the apparatus of the present invention can be used not only for coating high-viscosity coating materials but also for coating low-viscosity coating materials.

[Description of the second embodiment] Next, as in the second embodiment shown in FIGS. 4 and 5, the state in which the coating blade 3 is in contact with the coating roll 1 in non-coating state in FIG. It may also be moved downward.

Then, the coating material is applied to coating roll 1 and coating blade 3.
It passes through the gap, goes around the applicator roll 1, and returns to the paint reservoir between the doctor roll 2 and the applicator roll 1.

By moving the applicator blade 3 downward in this way, the lower roll 5a required in the first embodiment is removed.
Also, the coating material collection gutter 9 is no longer required, and the structure of the coating device is significantly simplified, and a series of conveyor rolls 6a
That's enough.

〔Effect of the invention〕

In this way, the present invention applies the coating material to the coating roll 1.
and the gap between the doctor roll 2 and the doctor roll 2.
In addition, in order to deposit a desired amount on the coating roll 1 and to apply it to the base material 7 by scraping it off with a coating blade 3 disposed perpendicularly or close to perpendicular to the surface of the coating roll 1, it is caused to flow down in a vertical curtain shape. When applying a high-viscosity coating material, the curtain-like flow is formed by the weight of the coating material, so it flows down at a constant amount.
Due to the viscosity of the coating material, the thickness becomes constant without the curtain-like disturbance. Therefore, roll tack does not occur, and the coating film has a uniform thickness.
Moreover, it is applied smoothly.

[Brief explanation of the drawing]

(First Embodiment) Fig. 1: Side view of the first embodiment of the present invention, Fig. 2: Enlarged view of the main parts thereof, Fig. 3:
Side view of another aspect of the present invention, (Second Embodiment) Fourth
Figure: Side view of the second embodiment of the present invention during painting, No. 5
Figure: Side view when not painted. 1: Application roll, 2: Doctor roll, 3: Application blade, 4: Receiving gutter, 5, 5': Lower roll, 5
a: Lower roll (Fig. 3), 6: Conveying device, 6a:
Conveyance roll, 7: Base material, 8: Scraping blade (Fig. 3), 9: Gutter for collecting coating material (Fig. 3), A: Substrate conveyance direction, B: Application roll rotation direction, C: Doctor Roll rotation direction, D: lower roll 5, 5' rotation direction, E: lower roll 5a rotation direction.

Claims (1)

[Scope of Claims] 1. A coating roll 1 that is rotationally driven in the same direction B as the conveying direction A of the substrate 7 to be coated, and a diameter larger than that of the coating roll 1 on the substrate carrying side of the coating roll 1. A doctor roll 2 that is small and rotates in a direction C opposite to the rotational direction of the application roll 1 at the contact portion with the application roll 1, and whose distance from the application roll 1 can be adjusted; A coating device for a plate-shaped object, comprising a coating blade 3 whose upper end is in contact with the surface of a coating roll perpendicularly or nearly vertically.