JP3252277B2 - Transfer type double-side coating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a duplex coating KoSo location to form at the same time resin film on both sides of a running web upwards, mirror films, cloth, paper, foil, punching plate, on both sides of the net-like sheet material, etc. It is used when forming a coating film.

[0002]

2. Description of the Related Art As this type of double-side coating apparatus, for example, the one shown in FIGS. 1 and 2 is known.
In the apparatus shown in FIG. 1, rubber rolls 3, 3 rotating in the same direction as the web 1 are arranged in parallel from both sides of the web 1 so as to press them, and both sides of the web 1 passed through a resin reservoir 4 provided thereunder. This is a coating apparatus in which resins 2 and 2 are adhered to a web, and the web 1 is guided between rollers 3 and 3 to squeeze out excess resin liquid to form a coating film. Although the thickness of the coating is designed by contact pressure of the rubber roller 3,3 in the case of the rubber roller Ru difficult der to finish the surface to a mirror surface. Ma
In addition, when the pressing force of the rollers is strong, fine streaks due to the roughness of the accuracy tend to be generated on the surface of the resin film, and when the pressing force is weak, the web 1 sways between the rollers. There is a disadvantage that the film thickness becomes unstable.

The apparatus shown in FIG. 2 is a coating apparatus in which cleaning doctors 6 are arranged on both sides of the web 1 instead of the rubber roller 3. However, it is very difficult to finish the doctor's edge with uniform accuracy over the entire length, and it is difficult to secure a uniform coating film on the left and right since thin edges must be installed facing each other. Fine irregularities may be generated due to the shaking of the web 1, and depending on the shape of the tip of the doctor 6, the resin liquid may adhere to the back side of the doctor and damage the coating film, which may cause the formation of streaks. is there.

[0004]

The present invention relates to a double-side coating apparatus for simultaneously forming a resin coating film on both sides of a web running upward,
An object of the present invention is to make the pressure of a coating film supplied uniform so that a stable mirror-like coating film can be formed on both surfaces of a web.

[0005]

[Technical means] technical means for solving this technical problem, transfer with a constant film thickness on the surface of the code <br/> coating roll for mirror finish passing through the (b) resin dam Apparatus for forming a coating film are arranged side by side with the coating roll inside, (b) the outer diameter of the coating roll is the same, and (c) the thickness of the web between the rolls is 8 to 12 μm.
Example was the width ungated a, transferring the coating film (d) of the coating roll between the web by rotating at a constant speed in opposite directions on both sides of the web simultaneously.

[0006] the coating roll is passed through the resin dam to form a coating film having a uniform film thickness, the coating will rotate with the roll remain attached to the surface of the roll, the coating
When the film is fed to a running web, the coating is transferred to the web
Will be done . An apparatus for forming this transfer coating film is as follows:
With the coating roll inside, they are arranged side by side
The thickness of the web
The transferred transfer coating is supplied at the same time . Coat
The printing roll is for mirror finishing, so
The side of the coated film that was in contact with the roll became the surface of the coated film.
Therefore, a mirror-like coating film is formed on the web .

[0007] In an outer diameter the same left right coating roll, because it is allowed to rotate at a constant speed in a direction opposite to the web, the web of the coating film is supplied from the left and right web travels upwardly between the rolls The pressure at the time of coating is the same. Interval of the roll surface comrades, 8~12μ to the thickness of the web
The web to be designed to a width obtained by adding m in a state no significant margin in the running distance. Also,
In this state, a coating film having the same pressure is supplied from the left and right sides and transferred onto the web, so that there is almost no load fluctuation at the time of transfer, and the web does not fluctuate between rolls.
Therefore, a stable coating film can be formed on both sides of the web using the transfer pressure of the coating film supplied.

[0008] spacing between the rolls, the type of web, running speed, in consideration of the kind and viscosity of the surface roughness and resin
It is set to a width plus 8~12μm to the thickness of U E Bed
However , if the thickness is smaller than 8 μm, the running may be hindered depending on the surface condition of the web, and if it exceeds 12 μm, the web may fluctuate if a slight difference occurs in the transfer pressure balance. When forming a transfer film with a uniform film thickness on the surface of a coating roll passing through a resin dam, a slit coater method using a fixed pipe type doctor roll (see Japanese Patent Publication No. 54-15571) or A reverse roll coater system using a roll that rotates in the opposite direction to the coating roll is desirable, but a system in which a doctor knife is simply arranged can also be employed. The method of determining the coating film and the gap between the coating rolls are determined by comprehensively considering the type and viscosity of the resin forming the coating film, the type of web, the running speed, and the like.
As the viscosity of the resin liquid, a resin liquid having a viscosity in the range of 500 to 30,000 cps conventionally used in transfer-type coating can be applied. The resin liquid may be aqueous or solvent-based.

[0009]

According to the present invention, the pressure of the resin solution to be applied can be made uniform and a stable mirror-like coating film can be formed on both surfaces of the web. As a result, there is an advantage that a glossy coating film can be formed at the same time. However, mirror-finish coating of 10 to 500 μm (but immediately after coating) is also possible.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a transfer apparatus 10 of a slit coater system using a fixed pipe type doctor roll 16.
1 is a schematic front view of a double-sided coating apparatus using two units. A resin dam 24 is disposed outside the gap between the coating roll 13 forming the transfer film 12 and the doctor roll 16. This dam 24 is provided with a resin supply slit 23 having a width adapted to the width of the coating roll 13,
A supply device (not shown) operates in accordance with the detection signal of the liquid level gauge 21 to supply the resin 2 into the dam 24. It is desirable to adjust the depth of the resin dam 24 according to the size of the gap between the coating roll 13 and the doctor roll 16. In this embodiment, by moving the plate 25 installed on the back to the adjusting screw 26,
The depth of the dam 24 can be adjusted. The opening of the dam 24 is closed by a lid 27 to prevent dust and dirt from entering the dam 24, thereby preventing a change in viscosity of the resin due to evaporation of the solvent.

In this embodiment, the coating film 12 is formed on both surfaces of the thin metal plate 1.
The gap between 3 and 13 is a gap obtained by adding 10 μm to the thickness of the metal plate 1. The coating film 12 whose film thickness is determined by the doctor roll 16 on the coating roll 13 is:
The coating roll 13 once moves downward according to the rotation of the rolls 13 which are rotating in the biting direction.
13 are simultaneously supplied from the left and right directions to the metal plate 1 traveling upward, and once face the gap between the metal plate 1 and the roll 13, and then transfer to the surface of the metal plate 1 to perform transfer. The transferred coating film 12 is subjected to a drying step in a state where it is applied to a metal plate as it is, but a cleaning doctor 14 is provided for the roll 13 so that a part of the coating film is Even if it remains on the surface of the roll 13, it is cut off and collected by the catch pan 15, the surface of the roll 13 is kept in a beautiful state and is exposed to the resin dam 24, so that a beautiful coating film is always formed. .

When coating a web or a net having a large number of holes, it is necessary to close the holes and voids in advance. In this case, the transfer by the transfer device 10 is performed. as the previous step, it intends row filling coating such as a hole. FIG. 4 is a schematic view of the filling and coating apparatus, in which a doctor contact pressure point 35 is provided at an upper portion of the resin dam 34, and the web 31 having the hole 32 is passed through the resin dam 34, and the resin is injected into the hole 32. After filling, the resin is passed through the doctor contact pressure point 35, and the resin on the surface of the web 31 is removed by the cleaning doctors 36, 36 arranged on the left and right at the time of passing, and the resin is filled only in the holes 32. The web 31 in which the holes 32 are closed in this way is guided to the transfer device 10 as it is, and the coating film 12 is formed on both surfaces.

[Brief description of the drawings]

Fig. 1 Conventional double-side coating device

FIG. 2 shows another conventional double-side coating device

FIG. 3 is a schematic cross-sectional view of a double-sided transfer device according to the present invention.

FIG. 4 is a schematic cross-sectional view of a filling coating apparatus used in a pre-process of double-sided transfer.

[Explanation of symbols]

1, web, 2, resin, 10 transfer device, 12 coating film, 13 coating roll, 14 cleaning doctor, 16 pipe type doctor roll, 21 liquid level gauge, 24 resin dam,

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B05C 1/08-1/12 B05C 11 / 04,5 / 02 B05C 9/04 B05D 1/28

Claims (1)

(57) [Claims] 1. A double-side coating apparatus for simultaneously forming a resin coating film on both sides of a web running upward, wherein a transfer coating having a constant film thickness is formed on a surface of a mirror-finish coating roll passing through a resin dam. The equipment for forming the film is arranged side by side with the coating roll inside, making the outer diameter of the coating roll the same and the thickness of the web between the rolls.
A double-sided coating apparatus that transfers coating films simultaneously on both sides of the web by rotating the coating rolls at the same speed in the opposite direction to the web, with a width of 8 to 12 μm .