JP2000117175A - Multilayer applicator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer applicator which controls the mixing of liquid in multilayer application and which improves the precision of film thickness. SOLUTION: An application head 1 has liquid storing parts 3a, 3b, 3c and nozzles for ejecting a coating liquid are formed from slots 4a, 4b, 4c led from the liquid storing parts 3a, 3b, 3c. A multilayer applicator in which the nozzle on the most upstream side has a wide opening part 5a, and the other nozzles have opening parts formed by the extension of the slots 4a, 4c is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus for applying a coating liquid to a running support in the production of wallpaper and the like, and more particularly to a coating apparatus for simultaneously applying a coating liquid having a different composition to a support. .

[0002]

2. Description of the Related Art Conventionally, there is a process of applying a paste to a backing paper in a process of manufacturing wallpaper or the like. This paste is obtained by adding a filler such as calcium carbonate to vinyl chloride, further adding various stabilizers and foaming agents as needed, and adjusting the viscosity by diluting with an organic solvent or the like.

[0003] As a method of applying such a paste to a backing paper, various coating methods such as a knife coater are conventionally used. The knife coater is for applying a sol-like paste to a support by stretching over a single layer by a blade-like knife edge.
There is an advantage that cleaning and the like can be easily performed.

[0004]

However, in a coating apparatus such as a knife coater in which coating is performed by running a support in a dam for storing liquid, when two or more layers are coated, mixing of liquids occurs. It was difficult to perform simultaneous multi-layer coating due to problems such as easy occurrence and difficulty in obtaining accurate film thickness for each layer.

A multi-layer coating method using a coating head having a plurality of slot nozzles is also widely used. In such a coating method, when the width of the nozzle opening on the most upstream side is as narrow as 5 mm or less, There has been a problem that the coating state is unstable and the coating surface is likely to be disturbed.

An object of the present invention is to solve the above-mentioned problems and to provide an apparatus for simultaneously performing multi-layer coating on a running support.

[0007]

According to a first aspect of the present invention, there is provided a coating apparatus for disposing a coating liquid on a support which is provided with a coating head for discharging a coating liquid facing a backup roll and which rotates by rotating the coating head. The head has a plurality of nozzles for discharging the coating liquid formed by a liquid reservoir for storing the coating liquid and a slot communicating with the liquid reservoir, and the nozzle at the most upstream side has a wide opening, The multi-layer coating apparatus is characterized in that the subsequent nozzles have openings formed by extending the slots.

According to a second aspect of the present invention, there is provided the multilayer coating apparatus according to the first aspect, wherein the gap between the downstream nozzle port and the support is larger than the gap between the upstream nozzle port and the support.

Further, in the third aspect, the height of the partition wall between each nozzle can be arbitrarily adjusted, and the multi-layer coating apparatus according to any one of the first and second aspects, And

<Operation> In the present invention, the nozzle opening on the most upstream side of the coating head is not formed into an elongated shape of the slot portion as in a general extrusion coating device such as a die coater, but is formed in a wide shape. This facilitates the application of the coating solution to the support, and makes it possible to obtain a uniform coating film even when a support or a coating solution having poor coating suitability is used. The second and subsequent nozzles can easily ensure uniform discharge of the coating liquid in the width direction by making the width of the opening part elongated from the slot part, and further reduce the height of the partition wall between the nozzles. By setting such that the gap with the support increases toward the side, mixing with the lower layer coating solution can be eliminated.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. FIG. 1 is a cross-sectional view showing a usage state when a coating head 1 and a backup roll 2 are arranged in a multilayer coating apparatus according to the present invention, and FIG. 2 is a cross-sectional view of only the coating head 1. The coating head is formed by a liquid reservoir 3 (a to c) and a slot 4 (a to c) communicating with the liquid reservoir. With a wide shape. Further, the second and subsequent nozzle openings 5b and 5c with respect to the traveling direction of the support have a shape extended from the slots.

The liquid reservoir 3 has a circular or substantially circular cross section, and extends in the width direction of the support with the same or substantially the same cross section. The inner diameter of the liquid reservoir 3 is 5
The best size is set to about 50 mm depending on the properties and viscosity of the coating solution.

The slot 4 is a slit-shaped coating liquid passage having a width of 0.3 to 1.0 mm communicating from the liquid reservoir 3 to the support.

Further, the most upstream nozzle opening 5a
Has a width of about 10 to 30 mm, and the second and subsequent nozzle openings 5 continue with the same width as the slot 4.
It is 3 to 1.0 mm.

The tip of the partition wall forming each nozzle has a sharp edge shape processed at an accuracy of 5/1000 mm or more on the most downstream side in the running direction of the support. The width of the tip of each partition wall is 2 mm. 〜１０10 mm.

Further, the height of the partition wall between the nozzles is set so that the distance from the support becomes larger as going from the upstream side to the downstream side, and the distance from the support can be arbitrarily adjusted. In addition, it is possible to obtain a multilayer coating having an arbitrary thickness in a favorable state.

[0017]

EXAMPLES The effects of the present invention will be described below in more detail with reference to examples. <Example 1> Two layers were applied under the following conditions. (1) Support material: Backing paper Weight: 70 g / m ² Width: 1000 mm (2) Coating liquid A vinyl chloride paste having a viscosity of 4000 cps as a lower layer (hereinafter referred to as coating liquid 1) and a viscosity of 2000 cps as an upper layer
(Hereinafter, coating solution 2) was used. (3) Thickness of coating layer Lower layer: 100 μm Upper layer: 20 μm

The shape of the coating apparatus and the operating conditions of the coating are as follows. Coating head: Lower layer coating section Slot width: 1.0 mm Nozzle opening width: 20 mm Downstream front edge-support interval: 90 μm Upper layer coating section slot width: 0.6 mm Downstream front edge-support interval: 135 μm Coating speed: 50-200m / min

When the coating was performed under the above-described coating conditions, a favorable two-layer coating state in which the respective layers were not mixed and the film thickness was uniform was obtained.

[0020]

As described above, by using the coating apparatus according to the present invention, it is possible to simultaneously apply a plurality of coating solutions having different compositions in a state where the film thickness is uniform and the coating film is less disordered. It is possible to obtain physical properties that could not be obtained by the single-layer coating of (1), and it is possible to realize cost reduction by reducing the number of steps.

[0021]

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a coating apparatus according to the present invention.

FIG. 2 is a schematic sectional view showing a coating head of the coating apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Coating head 2 ... Backup roll 3a ... 1st reservoir 3b ... 2nd reservoir 3c ... 3rd reservoir 4a ... 1st slot 4b ... Second slot 4c Third slot 5a First nozzle opening 6a, 6b, 6c Partition wall 7a, 7b, 7c Sharp edge 8 Supporter 9 Coating liquid 1 10 ... Coating liquid 2 11 ... Coating liquid 3

Claims (3)

[Claims] An application apparatus for applying an application liquid to a support that is run by the rotation of the backup roll is provided with an application head for dispensing the application liquid. A plurality of nozzles for discharging the coating liquid formed by a liquid reservoir for use and a slot communicating with the liquid reservoir, of which the nozzle at the most upstream has a wide opening, and the second and subsequent nozzles A multilayer coating device having an opening formed by extension of a slot. 2. The multi-layer coating apparatus according to claim 1, wherein the gap between the opening of the downstream nozzle and the support is larger than the gap between the opening of the upstream nozzle and the support. . 3. The multi-layer coating apparatus according to claim 1, wherein in the coating head, the height of a partition wall between each nozzle can be arbitrarily adjusted. .