JPS5955369A - Roll coating method for film - Google Patents

Abstract

PURPOSE:To prevent the sticking of a coating liquid on the top surface of a film, by spraying air from the central part of the film toward both-side edges on the top surface of the film just before the position where the film is nipped. CONSTITUTION:Air nozzles 4 are disposed at both-side edges on the top surface of a film F just before a nipping position, that is, on the side where the film F enters. The nozzles 4 are provided diagonally downward and divergently outward so as to direct the air blown through the nozzles from the central part of the film F toward the side edges thereby flowing away the coating liquid that is to be spread toward the top surface of the film F.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing a coating liquid from adhering to the other side of a film when coating one side of the film with a roll.

When coating one side of a thin film such as a plastic film, cellophane, or paper (hereinafter collectively referred to as a film) with various substances in liquid form, various problems occur if the coating liquid sticks to the other side of the film.

Conventionally, a device as shown in FIG. 3 was used, but it had various drawbacks and was not satisfactory.

That is, FIG. 3 is a perspective view of the main parts of a conventional roll coating apparatus, in which a liquid roll partially immersed in a coating liquid tank L and an upper presser roll 3 are used to coat a film F ( (indicated by the dotted line), and film F
It is used to coat the underside of the .

In order to prevent the coating liquid from passing between the rolls 13 and around the upper surface of the film F, a doctor blade/Q f is provided at a position corresponding to both side edges of the film F, and this doctor blade/Q f is used to prevent the coating liquid on the liquid roll λ. I was scraping off the liquid.

However, with this method, it is possible to completely prevent the coating liquid from adhering to the two sides of the film. There were problems such as scratches and uneven rotation of the liquid roll 2VC due to the doctor blade IO acting as a brake.

The present invention is a method that solves the above problems, and is characterized by blowing air onto both side edges of the top surface of the film instead of the conventional doctor grade.

The present invention will be explained below based on the drawings. Fig. 1 is a perspective view of an example of an apparatus for carrying out the method of the present invention;
- II sectional view, symbols 7 to 3 and F refer to the same things as in FIG. 3, g is an air nozzle, and ≠/ is a compressed air hose.

In the present invention, the air nozzle 4t is disposed immediately before the two-tube position, that is, on both sides of the upper surface of the film F, on the side where the film F enters. The air nozzle is opened diagonally downward and outward so that the air blows out from the center of the film F toward the side edges, and the air blows away the coating liquid that tends to get around to the upper surface of the film F.

Air nozzle installation position 1, 11. " may be adjusted appropriately depending on the speed of the film F and the weight of the coating liquid. For example, the distance between the tip of the air nozzle t and the top surface of the film F is /θ~, 20m+=a It is preferable to set the angle between the air nozzle and the film F to approximately 3θ to t00.

According to the method of the present invention, the coating liquid on the top surface of the film F is removed by the air blown outward on both side edges of the film F, and the coating liquid on the top surface of the film F is removed by the air.
Since the adhesion state of the coating liquid to @, is shown by the diagonal lines in Figure 2, there is no risk of the coating liquid going around between the liquid roll λ and the presser roll 3, and furthermore, unlike the conventional doctor grade method, There is no adverse effect on equipment or operation.

[Brief explanation of drawings]

1h is a perspective view showing an example of an apparatus for implementing the method of the present invention, FIG. 2 is a sectional view taken along line 1-II, and FIG. 3 is a perspective view of a conventional coating apparatus. /...Coating liquid tank No./&0-ru3...
Press t roll ≠... Air nozzle F... Film

Claims (1)

[Claims] The film is nipped between a liquid roll partially immersed in the coating liquid tank and a presser roll above it.
A method for coating the bottom surface of a film, characterized in that air is blown from a middle heat section of the film toward both side edges of the top surface of the film just before the film nip position to prevent coating liquid from adhering to the top surface of the film. Roll coating method for film.