JP3259042B2 - Knife coater and its knife - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a knife of a knife coater for uniformly applying a coating liquid on an upper surface of a running web.

[0002]

2. Description of the Related Art An example of a conventional knife coater is shown in FIGS.

The knife 100 of the knife coater includes a knife blade 102 and a knife holder 104 supporting the knife blade 102, and is disposed above a backup roller 106. A web 108 made of a film, paper, or the like is sent to a backup roller 106, passes through a coating liquid reservoir 112 provided by a dam plate 110 on the front side of the knife blade 102, and is coated with a coating film by the knife blade 102. 1
14 are formed.

Here, the knife blade 102 and the knife holder 1 are used.
04 is made of iron, which is plated with hard chrome. However, if it is iron, there is a problem that it is difficult to perform plating, and plating cannot be performed well.

For this reason, the material of the knife blade 102 is
Stainless steel is often used. However, since stainless steel has a larger coefficient of thermal expansion than iron, frictional heat between the web 108 and the coating liquid during coating and the knife 100
A change in ambient temperature causes the knife blade 102 to expand more than the knife holder 104, causing so-called bending in which the knife blade 102 bends. This allows
There is a problem that a difference in coating thickness occurs between the central portion and the end portion of the web, and the web cannot be coated uniformly.

Here, the knife holder 104 is placed on the knife blade 1.
Even with the same stainless steel material as 02, the knife blade 102, especially the blade tip, is always in contact with the coating liquid in the liquid reservoir 112, so it is easily affected by the temperature of the coating liquid, and the bending of the blade tip is reduced. There is a problem that it cannot be suppressed sufficiently.

[0007] In view of the above, it is an object of the present invention to provide a knife of a knife coater capable of adjusting the bending of a knife blade.

[0008]

According to a first aspect of the present invention, there is provided a knife of a knife coater for uniformly applying a coating liquid on a running web, wherein the knife has a blade tip inside.
A hollow portion for flowing a temperature control liquid is provided along the width direction of the web.

A knife according to a second aspect of the present invention is the knife of the knife coater according to the first aspect, wherein the knife edge portion comprises:
The knife blade tip includes a main body, and a cover member detachably provided on the back surface of the knife blade tip body, wherein the hollow portion is formed between the back surface of the knife blade tip body and the lid member. The inflow hole and the outflow hole of the temperature control liquid are provided in the lid member. A knife coater according to a third aspect of the present invention includes the knife according to the first or second aspect.
A knife coater, wherein the knife edge is coated with a coating liquid.
When the reverse vent occurs so that it can be pushed up,
Liquid for temperature control in the hollow part so as to cancel the
Is flowing.

[0010]

In the knife according to the first aspect of the present invention, a temperature controlling liquid is caused to flow through the hollow portion to keep the temperature of the knife edge portion constant.

In the knife of the second aspect of the present invention, the hollow portion is formed by the back surface of the knife blade tip body and the lid member, and the lid member is detachably provided on the back surface of the knife blade tip body. . Further, the temperature control liquid flows into the hollow portion from the inflow hole and is discharged from the outflow hole.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A knife 10 according to an embodiment of the present invention will be described with reference to FIGS. This knife 10
Is applied to the knife coater of FIG. 7 instead of the conventional knife 100 described above.

Reference numeral 12 denotes a plate-like knife blade having a width corresponding to the coating width of the web 108, and is made of stainless steel. The lower end of the knife blade 12 has a front side 1
A cutting edge portion 14 is provided which is inclined obliquely downward from the rear side 2a toward the rear side 12b.

Reference numeral 16 denotes a lid member made of stainless steel and attached to the back surface 12b of the knife blade 12 with bolts 17. The cover member 16 is attached to the blade edge portion 14 over substantially the entire width of the knife blade 12.

Reference numeral 18 denotes a hollow portion formed by a groove 18a provided on the front surface of the lid member 16 and the back surface 12b of the knife blade 12. The hollow portion 18 has an elongated shape over substantially the entire width of the lid member 16. An inflow hole 20 is provided at one end of the hollow portion 18 and an outflow hole 22 is provided at the other end thereof.
Penetrates the back of the. Pipes 32 and 34 are attached to the holes 20 and 22, respectively.

Reference numeral 24 denotes an O-ring surrounding the hollow portion 18 for preventing water leakage. The O-ring 24 is made of rubber elastic material, and is fitted into O-ring grooves 26 and 28 provided on the knife blade back surface 12b and the front surface of the lid member 16 in close contact with each other.

Reference numeral 29 denotes a hole provided in the cover member 16, through which a bolt 17 for fixing the cover member 16 is inserted.

Reference numeral 30 denotes an iron knife holder for supporting the knife blade 12. The knife holder 30 has a columnar shape having a cutout portion 30 a having a fan-shaped cross section, and is slightly longer than the width of the knife blade 12. The upper portion of the back surface 12b of the knife blade 12 is screwed to the vertical surface of the notch 30a. The knife holder 30 has a shaft 5 protruding from both ends thereof.
4 is provided on a frame (not shown) of the knife coater so as to be rotatable around the center.

Reference numeral 31 denotes a screw hole provided on the upper portion of the knife blade 12, through which a bolt (not shown) for fixing the knife blade 12 to the knife holder 30 is inserted.

On the back surface of the knife holder 30, similarly to the knife blade 12, a hollow portion 38 is provided by a lid member 36. The lid member 36 has an arcuate cross section and forms an arc on the back of the knife holder 30. O-ring 4
The O-ring grooves 42 and 44, the inflow hole 46 and the outflow hole 48 of the lid member 36, and the pipes 50 and 52 are also formed in the same manner as the knife blade 12.

Next, the process of coating the web 108 using the knife 10 will be described.

The web 108 is a backup roll 106
, And is fed into the liquid reservoir 112, further passes between the backup roll 106 and the knife blade 12 of the knife 10 installed above the backup roll 106, is separated from the backup roll 106, and proceeds to the next step.

At this time, the coating liquid passes through a small linear orifice formed by the upper surface of the web 108 and the tip of the knife blade 12 to form a coating film 114. In order to form a uniform coating 114 in the width direction of the web 108, the orifice must be uniform in the width direction.

Water adjusted to a constant temperature is fed into the hollow portion 18 from the pipe 32 through the inflow hole 20, flows through the hollow portion 18, and is discharged from the outflow hole 22 and the pipe 34. Inside the hollow portion 18, the water and the knife blade 12 exchange heat with each other, so that the temperature of the knife blade 12, particularly the temperature of the cutting edge portion 14 thereof, can be kept constant.

For example, if water adjusted to a constant temperature of about 25 ° C. is allowed to flow through the hollow portions 18 and 38, not only the knife blade tip portion 14 but also the entire knife 10 including the knife holder 30 can be processed at the time of their processing. Because it can be kept at a temperature
The coating operation can be performed with the knife precision at the time of knife processing, and a uniform coated film 114 can be obtained.

When water adjusted to a high temperature is allowed to flow through the hollow portion 18, the knife edge 14 bends and the web 1
08, the amount of coating at the center is reduced. As described above, by adjusting the temperature of the water flowing through the hollow portion 18, the bend amount of the knife edge portion 14 can be adjusted, and therefore, the coating amount at the central portion of the web 108 can be controlled.

Therefore, even if the coating liquid acts to push up the knife blade tip 14 and reverse bends occur in the knife blade tip 14, high-temperature water flows through the hollow portion 18 to cancel the reverse bend. Thus, uniform coating can be performed in the width direction of the web 108.

As described above, at the time of coating, the coating film 1
While observing the state of 14, so that the desired state
The temperature of the water flowing through the hollow portions 18 and 38 can be adjusted.

In the knife 10, the cover member 16 is attached to the knife blade back surface 12b because the tip of the blade edge portion 14 is flatter than the knife blade front surface 12a. That's why. Further, since the liquid reservoir 112 for the coating liquid is located on the front side 12a of the knife blade, the lid member 16 is not immersed in the coating liquid during coating.

Since the hollow portion 18 is formed by providing the groove 18a in the lid member 16, even if the knife blade 12 is thin, it can be formed irrespective of its thickness.
Since the groove is not machined, the knife edge 1
4 does not decrease in accuracy.

The O-ring 24 serves to prevent water flowing in the hollow portion 18 from leaking from the contact surface between the knife blade back surface 12b and the cover member 16. Thereby, the accuracy of the contact surface does not have to be so high.

The knife blade 12 is not limited to a stainless steel material, but may be a steel blade plated with hard chrome. However, stainless steel is preferable because even if the knife edge portion 14 having a complicated shape is damaged, the wound can be easily corrected.

The cover member 16 does not necessarily have to be made of the same material as the knife blade 12, but is preferably made of the same material because of the same thermal expansion coefficient.

The knife holder 30 may not be made of iron, and may be made of the same stainless steel material as the knife blade 14, but is preferably made of hard chrome plated iron in terms of cost.

In this embodiment, since the knife holder 30 is made of iron, it is not always necessary to provide the hollow portion 38 unless the ambient temperature during coating is particularly high.

Next, a knife 10 according to another embodiment of the present invention will be described.

In the knife 10 shown in FIG.
A groove 18b provided on the back surface 12b of the cover member 16 and a groove 18a provided on the front surface of the lid member 16 form a hollow portion 18 through which water for temperature control flows.

In the knife 10 shown in FIG.
A hollow portion 18 through which water for temperature control flows is formed by a groove 18b provided on the back surface 12b of the cover member 16, and no groove is provided in the lid member 16.

Also in these cases, the temperature of the knife edge portion 14 can be adjusted by the method described above.

In the knife 10 described above, the hollow portion 1
Since the blade 8 is provided along the removable lid member 16, the hollow portion can be easily formed regardless of the material of the knife blade 12. Moreover, the hollow member 18 can be easily cleaned by removing the lid member 16.

As described above, regardless of the material of the knife 10, the knife 10 whose bending can be adjusted and whose temperature of the cutting edge portion 14 can be controlled with a simple structure can be obtained.

The temperature control liquid flowing through the hollow portions 18 and 38 is not limited to the above-mentioned water, and can be variously used depending on the purpose. Water or an aqueous solution is preferred.

[0043]

According to the knife of the first aspect of the present invention, the temperature of the knife edge is controlled so as to be independent of the material of the knife.
The bending of the knife edge can be controlled.

Therefore, the stability of the coating is obtained without being affected by the change in the surrounding temperature, the coating can be performed uniformly in the width direction of the web, and the coating amount at the center of the web is adjusted. Can also.

According to the knife of the second aspect of the present invention, a hollow portion can be easily provided at the knife blade tip regardless of the thickness of the knife, and the hollow portion can be easily removed by removing the lid member. Maintenance is possible. In addition, since they are provided on the back side of the knife blade tip, they are less affected by the temperature of the coating liquid reservoir on the front side of the knife blade.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a knife 10 according to one embodiment of the present invention.

FIG. 2 is a rear view of the knife 10 according to the embodiment of the present invention.

FIG. 3 is a perspective view of the knife blade 12;

FIG. 4 is a perspective view of a lid member 16;

FIG. 5 is a longitudinal sectional view of a blade edge portion 14 of a knife 10 according to another embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of a cutting edge portion 14 of a knife 10 according to another embodiment of the present invention.

FIG. 7 is a longitudinal sectional view of a knife coater provided with a conventional knife 100 during coating.

FIG. 8 is a rear view of the conventional knife 100.

[Explanation of symbols]

 Reference Signs List 10 Knife 12 Knife blade 12b Back surface of knife blade 14 Knife blade tip 16 Knife blade lid member 18 Knife blade hollow portion 20 Inlet hole 22 Outflow hole

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-329419 (JP, A) JP-A-63-310670 (JP, A) JP-A-59-102176 (JP, U) International publication 93/10309 (WO, A1) (58) Field surveyed (Int. Cl. ⁷ , DB name) B05C 11/02, 11/04 B05C 3/18

Claims (3)

(57) [Claims] 1. A knife of a knife coater for uniformly coating a running web with a coating liquid, wherein a hollow portion for flowing a temperature control liquid along a width direction of the web is provided inside a cutting edge of the knife. A knife of a knife coater characterized by being provided. 2. The knife blade tip portion comprises a main body of the knife blade tip portion, and a lid member detachably provided on a back surface of the knife blade tip portion main body. The knife of the knife coater according to claim 1, wherein an inflow hole and an outflow hole of the temperature control liquid are formed between a back surface and the lid member, and the lid member is provided with an inflow hole and an outflow hole of the temperature control liquid. (3) A knife provided with the knife according to claim 1 or 2.
Fucota, So that the knife blade tip is pushed up by the coating liquid
So that when a reverse vent occurs,
Flow the liquid for temperature control into the hollow part Characterized by
Knife coater.