JPH0529106Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to a gravure coating machine, and is particularly capable of effectively applying a coating agent even to thin substrates, and easily coating a small amount. The present invention relates to a gravure coating machine that can also perform multi-color coating well.

[Prior art and its problems]

Generally, when coating a substrate made of resin film, paper, cloth, etc., it is necessary to prevent the coating agent from turning around to the back side of the substrate.

In order to prevent this back-rolling, coating has conventionally been applied to areas narrower than the entire width of the base material.

For example, as shown in FIG. 3, when coating the base material 1 using the wire bar 2, the wire bar 2
Small-diameter step portions 3, 3 are provided at both ends of the
The coating width ω of the wire bar 2 was formed to be narrower than the full width W of the base material 1.

However, when the stepped portion 3 is formed on the wire bar 2, there is no problem when the base material 1 is sufficiently thick, but when the base material 1 is thin, for example, the thickness is about 2 μm to 9 μm,
There was a problem in that vertical wrinkles were generated in the base material 1 at the stepped portion 3, resulting in poor coating.

Further, in the conventional gravure coating machine shown in FIG. 4, a similar problem occurs in that vertical wrinkles occur when coating a thin base material 1.

This is because in the conventional gravure coating machine, the base material 1, which is wound and stretched around the stretching rolls 4, is applied with an appropriate pressure by the lower gravure roll 5 and the upper rubber roll 6. Since the coating agent on the gravure roll 5 is applied to the lower surface of the base material 1 while being held, if the base material 1 is thin, vertical wrinkles will occur in the base material 1 due to the pressing force. It was hot. In the figure, numeral 7 is a doctor blade, and 8 is a pan for storing the coating agent.

Therefore, the present applicant has solved these problems by creating a "gravure coating machine" in Utility Application No. 136404/1984 (see Publication No. 7663/2003), which can cause vertical wrinkles even on thin substrates. A gravure coating machine has been proposed that can always perform good coating without any problems, and can also perform multicolor coating well.

[Purpose of invention]

The present invention was developed in consideration of these points, and in addition to the above-mentioned application, it is possible to easily apply a small amount of coating to a thinner substrate, easy to replace the rod, and moreover, it can be applied in multiple colors. It is an object of the present invention to provide a gravure coating machine that can perform satisfactorily.

[Summary of the idea]

The gravure coating machine of the present invention consists of a gravure roll that coats the bottom surface of a moving continuous base material at a position where the top surface is in a free state, and a gravure roll that coats the bottom surface of the base material in a position where the top surface of the continuous base material is in a free state. In a gravure coating machine equipped with a doctor blade that wipes off the agent before coating, the gravure roll is formed to have a diameter of 20 to 50 mm, and the coating material is stored and the lower part is inserted into the coating material. The upper surface has a storage section for applying a coating material to the gravure roll being immersed, and the cross-sectional area of the storage section is about 2 to 2.5 times the cross-sectional area of the gravure roll, and the average depth is about 2 to 2.5 times the cross-sectional area of the gravure roll. It is characterized by having a coating agent reservoir whose radius is 1.2 times or more the radius of the gravure roll.

[Example of idea]

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

1 and 2 show an embodiment of the present invention. In this embodiment, a continuous base material 11 is run horizontally from left to right in FIG. This base material 11 is unwound from a raw roll (not shown), and as shown in FIG.
2, and finally wound up by a take-up roll (not shown). One expansion roll 12
(in this embodiment, the right side in FIG. 1) is supported so as to be vertically movable. Then, two stretching rolls 12,1
A gravure roll 13 having a relatively small diameter of about 20 mm is horizontally suspended below the base material 11 at the middle portion of the roll. This gravure roll 13 is mounted on a base 14 that is moved up and down by an appropriate drive mechanism (not shown).
It is rotatably supported by a pair of support members 15, 15 erected above with bearings 16, 16.
Rotational force is transmitted to this gravure roll 13 from a drive motor via a coupling (both not shown). In this embodiment, gravure roll 1
3 is rotated in a direction opposite to the traveling direction of the base material 11 (counterclockwise in FIG. 1) at the contact portion. Furthermore, an engraved portion 17 having a width narrower than the entire width of the base material 11 is engraved on the outer peripheral surface of the gravure roll 13. Coating agent A is placed on the base 14 below this gravure roll 13.
A coating agent reservoir 18 for storing the coating agent is fixed by a tightening bolt 19. A reservoir 20 for storing the coating agent A is formed on the upper surface of the coating agent reservoir 18, and the gravure roll 13 has an engraved portion 17 therein.
Coating agent A is applied to the inside by dipping the lower part of the container into coating agent A. And this storage section 20
The width of the engraving portion 17 is the same as that of the engraving portion 17. In addition, the volume of the storage section 20 is as shown in FIG.
Its cross-sectional area is approximately 2 of the cross-sectional area of the gravure roll.
~2.5 times, and the average depth is 1.2 times or more the radius of the gravure roll, and the size is such that, for example, a small amount of low-viscosity coating agent A can be stored and applied to the thin base material 11 in a small amount. The capacity of this storage section 20 is determined based on the above-mentioned cross-sectional area and depth, so that when a small amount of coating is applied and a coating test is performed, at least the amount of coating that can be evaluated allows the test results to be evaluated. It is best to decide according to the design conditions within a certain range. Width regulating closing members 2 are provided at both ends of the coating agent reservoir 18 to close both ends of the reservoir 20.
1 and 21 are fixed. Further, immediately before the engraving part 17 of the gravure roll 13 applies the coating agent A stored in the storage part 20 to the base material 11, the engraving part 17 of the gravure roll 13
A doctor blade 22 is provided for wiping off excess coating agent applied to the coating material 7 . This doctor blade 22 is also formed to have the same width as the engraving portion 17. This doctor blade 22 is attached to a holder 24 rotatably supported on a pivot shaft 23 parallel to the gravure roll 13. Storage portions 20 are provided inside the coating agent reservoir 18, the center of the gravure roll 13, and the base 14, respectively.
There are built-in heaters 25, 25, . These heaters 25 are used, for example, when heating the coating agent A, which has the property of solidifying at room temperature, to an appropriate temperature so that it can be coated. In this case, heating is performed while monitoring the temperature using temperature sensors 26, 26, . . . installed at appropriate positions.

Next, the operation of this embodiment will be explained.

In the following, a case will be described in which coating agent A, which has the property of solidifying at room temperature like wax, is applied.

First, the spreading roll 12 on the right side in FIG. 1 is raised to the position indicated by the chain line in the same figure, so that the base material 11 is separated from the upper peripheral surface of the gravure roll 13. At the same time, each heater 2 built in the gravure roll 13, the coating agent reservoir 18, and the base 14
5 is heated to maintain the coating agent A filled in the reservoir 20 at an appropriate temperature (for example, 100 to 150° C.) and in a molten state ready for coating. Next, the coating agent A that has been melted in advance is filled into the reservoir 20 of the coating agent reservoir 18 . The filling amount of this coating agent A is desirably
Approximately the lower half of No. 3 is immersed in coating agent A. Then, each temperature sensor 26
While monitoring the temperature of the coating agent A inside, the energization state of each heater 25 is controlled to maintain the appropriate temperature of the coating agent A. Thereafter, the gravure roll 13 is rotated counterclockwise in the figure. Then, gravure roll 13
The portion of the engraving section 17 immersed in the coating agent A is filled and supplied with the coating agent A, and advances in the direction of the doctor blade 22 as the engraving section 17 rotates. The coating agent A filled in this engraving part 17 is
The excess amount is wiped off by the doctor blade 22, and the appropriate amount is filled and supplied only to the entire width of the engraving portion 17. The excess coating agent wiped off by the doctor blade 22 is supplied to the engraving section 17 again or returned to the storage section 20. When the appropriate amount of coating agent A is supplied into the engraving portion 17 of the gravure roll 13 in this way, the gravure roll 13 is moved together with the base 14 to the predetermined coating position (first
Then, the spreading roll 12 in the raised position is lowered to the solid line position in the figure, and the engraving part 17 of the gravure roll 13 is brought into contact with the lower surface of the base material 11, and the coating agent in the engraving part 17 is raised. A as base material 11
Coat on the bottom surface of.

In this case, since the traveling direction of the base material 11 and the rotating direction of the engraved part 17 are opposite directions at the mutual contact portion, the engraved part 17 is slipping with respect to the lower surface of the base material 11. As a result, the pattern of the engraving portion 17 coated on the lower surface of the base material 11 is
As a result, the coating agent is coated on the lower surface of the base material 11 in a uniform and smooth state. This smoothness is determined by the base material 11 and the gravure roll 1.
It is adjusted by changing the relative speed difference with 3.
As a result, according to this embodiment, the smoothing device can be omitted. Further, since a rubber roller for processing is not provided on the opposite side of the gravure roll 13 for the base material 11, the coating agent can be applied extremely well without vertical wrinkles even if the base material 11 is thin. .

In this embodiment, in order to facilitate the application of a small amount of coating agent A, the volume of the storage section 20 is made small. When replacing A with another one, the inside of the storage section 20 can be cleaned extremely easily and quickly, reducing the rod replacement work to about 1/10 of the conventional work.
can be shortened to In particular, when testing the matching between the base material 11 and the coating agent A, the coating agent A and the gravure roll 13 are frequently replaced during the coating test. Since the coating test can be performed by using a small amount of coating agent A ranging from cc to several hundred cc and the small diameter and lightweight gravure roll 13, these can be exchanged extremely easily and quickly. Coating tests can be performed extremely efficiently. In contrast, in the conventional example, the transfer roll has a large diameter and is heavy, and the amount of coating agent filled in the storage container is extremely large, several liters, so it takes a long time to replace them. At the same time, a large amount of used coating agent remaining in the reservoir after the coating test has to be discarded, resulting in a problem that a large amount of coating agent is wasted.

In addition, in this embodiment, the coating agent A in the storage section 20 can be constantly heated to an appropriate temperature by the heater 25 to be in an optimal state for coating, and the coating agent A that solidifies at room temperature However, the base material 11
Coated to. Since the coating agent A applied onto the base material 11 is applied very thinly, upon contact with the outside air after coating, the temperature rapidly decreases and solidifies. As a result, the coating of the coating agent A is completed, and the drying process of the coating agent A becomes unnecessary, and it is possible to speed up the coating and improve efficiency.

In addition, since the gravure roll 13 has a small diameter,
The contact area with the lower surface of the base material 11 is extremely small compared to a large-diameter gravure roll, and the contact with and separation from the base material 11 is improved. Due to the synergistic effect of the fact that the and the opposite directions, it is possible to accurately start and stop the application.
Furthermore, the cost of the gravure roll 13 is reduced, the entire machine is made smaller, and the drive for vertical movement can also be made smaller. In addition, the base material 11 and the gravure roll 13
By adjusting the relative speed of the gravure roll 13 by changing the rotational speed of the gravure roll 13, the coating thickness of the coating agent on the base material 11 can be adjusted in addition to the smoothing adjustment described above.

Note that in this embodiment, the gravure roll 13
The diameter of the gravure roll 13 is approximately 20 mm, but as long as the diameter of the gravure roll 13 does not cause vertical wrinkles on the base material 11 and can maintain good contact with and separation from the base material 11, Depending on the properties of the agent A, etc., it may vary, for example, between about 20 and 80 mm. In addition, as the heater 25 for heating and melting the coating agent A, in addition to a sheathed heater using electric energy, a heater 25 that circulates heating steam, a heat medium, or a known technical means may be used as necessary. Good to use. Further, as for the temperature sensor, a known sensor capable of directly or indirectly measuring the temperature of the coating agent A in the storage section 20 may be used as necessary.

Moreover, if a plurality of gravure coating machines of the present invention shown in FIGS. 1 and 2 are provided in the running direction of the base material 11 and coating agents of different colors are supplied to each,
Multicolor coating can be done extremely well.

That is, for example, cyan, magenta, and yellow coating agents are fed to three gravure coating machines, and the gravure coating machines are lowered until the areas to be coated with each color of the base material 11 are reached. Wait for the base material 11
When the area to be coated comes, the gravure coating machine is raised and the engraving part 17 of the gravure roll 13 is coated.
is brought into contact with the lower surface of the base material 11 to coat the lower surface of the base material 11 with a coating agent of each color.

In this case, according to the gravure coating machine of the present invention, even if the waiting time is long, the appropriate amount of coating agent can always be supplied into the engraving portion 17 by the doctor blade 22 at the start of coating. Therefore, a large amount of coating material is not applied to the coating start area, which would be expected in the case of a coating machine that uses a wire bar in the same way, and it is possible to maintain a uniform coating thickness over the entire area. It can be coated evenly.

Furthermore, similar multi-color coating can be applied using a conventional gravure coating machine shown in Figure 4, in which the substrate is sandwiched between two rolls, an offset gravure coating machine, or a flexo printing machine. However, since the base material is held between rolls, it is difficult to coat the thin base material well due to vertical wrinkles, and it is also necessary to move the two rolls closer to each other. Yes, the entire device is large and complicated, resulting in high costs.

In contrast, the gravure coating machine for multicolor coating according to the present invention has a simple configuration, is small in size, and is inexpensive. In particular, the installation space and cost are 1/8 to 1/3 that of conventional models.

[Effect of idea]

Since the gravure coating machine of the present invention is constructed and operates in this way, it can coat well without vertical wrinkles even when the substrate is thin, making it extremely easy to coat small quantities. In addition, rolls and coating agents can be exchanged quickly, making it possible to perform coating tests extremely easily, as well as eliminating waste of coating agents and saving resources. Furthermore, the smoothing of the coating agent and the coating thickness can be freely adjusted, and multi-color coating can always be performed well with a simple configuration, thereby providing a coated product with high commercial value. It has the following effects:

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing an embodiment of the gravure coating machine of the present invention, Fig. 2 is a reduced sectional view taken along the - line in Fig. 1, and Fig. 3 is a side view showing the state of coating with a wire bar. FIG. 4 is a side view of a conventional gravure coating machine. 11... Base material, 13... Gravure roll, 17
...Engraving portion, 18...Coating agent reservoir, 20...Reservoir portion, 21...Side wall, 22...Doctor blade, 25...Heater, A...Coating agent.

Claims (1)

[Scope of Claim for Utility Model Registration] 1) A gravure roll that coats the lower surface of a traveling continuous base material at a position where the upper surface of the base material is in a free state, and excess coating from the surface of this gravure roll. In a gravure coating machine equipped with a doctor blade for wiping off the coating material before coating, the gravure roll is formed to have a diameter of 20 to 50 mm, and the coating material is stored and a lower part of the coating material is coated. It has a reservoir part on the upper surface for applying the coating material to the gravure roll immersed in the gravure roll, and the cross-sectional area of the reservoir part is about 2 to 2.5 times the cross-sectional area of the gravure roll, and the average depth is A gravure coating machine characterized by being provided with a coating agent reservoir whose radius is 1.2 times or more the radius of the gravure roll. 2) The gravure coating machine according to claim 1, wherein the gravure roll, doctor blade, and coating agent reservoir are formed so as to be able to move toward and away from the lower surface of the substrate. 3) A plurality of sets of gravure rolls, doctor blades, and coating agent reservoirs are provided in the traveling direction of the base material, and each set is independently provided so as to be freely movable toward and from the bottom surface of the base material. A gravure coating machine according to claim 1 of the utility model registration claim.