JP2001009342A - Die head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out coating with even film thickness in the width direction by extruding a coating liquid out of the tip end of a slot part at a uniform flow rate in the width direction. SOLUTION: This die head is provided with manifolds for spreading a coating liquid from a liquid inlet 14 in the width direction and a slot part 15 with a constant thickness through which the coating liquid is extruded from the manifolds. In the die head with such a structure, two manifolds, a first manifold 13a in the inlet side and a second manifold 13b in the slot part side, are installed in parallel and the gap 16 between the first manifold 13a and the second manifold 13b is so tapered as to be widened from the center part outward to both sides and thus the discharge precision of the coating liquid in the width direction from the slot part can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extrusion die head used for applying a coating liquid to a continuously running web.

[0002]

2. Description of the Related Art Conventionally, an extrusion type die head has been widely used in various fields because it can perform uniform thin film coating. This type of die head includes a manifold for spreading the coating liquid from the liquid inlet in the width direction, and a slot for extruding the coating liquid from the manifold. As the shape of the manifold, there are a coat hanger type, a T-type, and the like, and a coat hanger type is often used for a coating liquid having a large thixotropic property. The shape of the manifold is important in order to improve the accuracy of discharging the coating liquid in the width direction from the slot portion. In a coat hanger type, for example, by changing the length from the manifold to the tip of the die head in the width direction. Discharge accuracy is controlled.

[0003]

FIG. 1 shows an example of a conventional die head having a hanger coat type manifold. FIG. 1 (a) is a sectional view at the center, and FIG.
(B) is a plan view showing the die lower plate by removing the die upper plate and both side plates. In FIG. 1, 1 is a die upper plate, 2 is a die lower plate,
Reference numeral 3 denotes a manifold, and a coating liquid supplied into the die head from a liquid inlet 4 provided in the die lower plate 2 is spread in the width direction by the manifold 3 and discharged from the tip of the slot portion 5 to travel. Coated on top. The discharge accuracy of the coating liquid from the slot portion 5 of the die head can be made uniform by changing the distance indicated by the arrow from the manifold 3 to the tip.

[0004] Depending on the physical properties of the coating liquid such as thixotropic properties, some inks require the central portion to have a longer length, and the entire die head becomes longer, requiring a large occupied space. In addition, it is necessary to process the manifold obliquely with respect to the die head main body, and it is difficult to process the manifold with high accuracy.

FIG. 2 shows another example of a conventional die head having a hanger coat type manifold. FIG. 2 (a) is a cross-sectional view at the center, and FIG. 2 (b) shows a die upper plate and both side plates. It is a top view which removes and shows a die lower plate. Although this die head is obtained by processing the internal manifold 3 into a quadratic curve, the processing becomes more difficult than the linear manifold shown in FIG.

[0006]

In order to solve such a problem, according to the present invention, the shape of the manifold in the die head is made such that the pressure loss of the coating liquid flowing therethrough is constant. By adopting such a shape, the coating liquid is extruded at a uniform flow rate in the width direction from the tip of the slot portion adjacent to the manifold, and coating with a uniform film thickness in the width direction becomes possible.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a die head having a manifold for spreading a coating liquid from a liquid inlet in a width direction, and a slot having a constant thickness through which the coating liquid is extruded from the manifold. A first manifold on the inlet side and a second manifold on the slot side are provided side by side, and a gap between the first manifold and the second manifold is tapered so as to extend outward from both sides from the center to the center. It is like that.

FIG. 3 shows an example of a die head according to the present invention. FIG. 3 (a) is a cross-sectional view at the center, and FIG. 3 (b) shows a die lower plate by removing a die upper plate and both side plates. Plan view, FIG. 3
FIG. 3C is a cross-sectional view showing the lower plate and the upper plate at a position corresponding to line XX in FIG.

In FIG. 3, reference numeral 11 denotes a die upper plate, 12 denotes a die lower plate, 13a and 13b denote a first manifold and a second manifold provided side by side, and a coating liquid is supplied to the die lower plate 12. The liquid inlet 14 is provided, the liquid inlet 14 is connected to the first manifold 13a, and the slot portion 15 is connected to the second manifold 13b. The first manifold 13a and the second manifold 13b are formed by two groove-shaped recesses provided on the die lower plate 12 and a flat inner surface of the die upper plate 13. Since the boundary between the two recesses is slightly lower, the two manifolds 13
The gaps a and 13b are connected by a gap 16, and the gap 16 has a taper that extends outward from both sides from the center (the position indicated by the dotted line). The taper is designed so that the pressure loss of the coating liquid passing through the first manifold 13a and the second manifold 13b is constant.

As described above, by changing the gap between the first manifold 13a and the second manifold 13b in the width direction, the discharge accuracy of the coating liquid from the slot 15 of the die head is improved. Unlike the coat hanger type, the distance from the manifold to the tip is not changed, so the length of the die head does not become longer depending on the type of coating liquid. Work accuracy can be improved. Also, since the manifold itself is a straight type,
Processing is easy and accurate processing is possible.

[0011]

As described above, in the die head of the present invention, the manifold shape is a double manifold of the first manifold on the inlet side and the second manifold on the slot side, and the manifold between the first manifold and the second manifold is formed. With the specification in which the gap is changed in the width direction, the entire die head can be shortened, so that the occupied space can be kept small. In addition, since the manifold itself may be a straight type, processing of the manifold is not complicated, and processing with high accuracy is possible.

[Brief description of the drawings]

FIG. 1 shows an example of a conventional die head having a hanger coat type manifold. FIG. 1A is a cross-sectional view at the center, and FIG. It is a top view showing a board.

FIG. 2 shows another example of a conventional die head having a hanger coat type manifold. FIG. 2 (a) is a cross-sectional view at the center, and FIG. 2 (b) shows a state where a die upper plate and both side plates are removed. It is a top view which shows a die lower plate.

FIG. 3 shows an example of a die head according to the present invention.
3 (a) is a cross-sectional view at the center, FIG. 3 (b) is a plan view showing the die lower plate by removing the die upper plate and both side plates, and FIG. 3 (c) is XX in FIG. 3 (b). It is sectional drawing which shows a lower board and an upper board in the position corresponding to a line.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Die upper plate 12 Die lower plate 13a 1st manifold 13b 2nd manifold 14 Liquid inlet 15 Slot part 16 Gap

Claims (1)

[Claims] 1. A first manifold on the inlet side of a die head having a manifold for spreading a coating liquid from a liquid inlet in a width direction and a slot having a constant thickness through which the coating liquid is extruded from the manifold. And two of the second manifolds on the slot side are provided side by side,
A die head characterized in that a gap between a first manifold and a second manifold is provided with a taper that extends outward from both sides from a central portion.