JPH01137250A - Coating device - Google Patents

Abstract

PURPOSE:To measure the spacing between a web and air back roll of a web coating device by following up to the deformation of the roll by holding an optical type displacement sensor for measuring the spacing between the web and air back roll to the air back roll in such a manner that said sensor can be moved by a pressurizing mechanism. CONSTITUTION:The web 1 is supported in a contactless state by the air blown from the air back roll 2. A coating liquid supplying device 3 exists in proximity to the roll 2 and coating liquids are coated on the web 1. The optical type displacement sensor 11 is provided in the roll 2 in this constitution. A flange 13a of a cap 13 of the sensor 11 is placed on the side 2b of the roll 2 opposite to the web 1 via an annular rubber elastic body 14. The cap 13 is fixed to the roll 2 via a leaf spring 17. The spring 17 is kept energized at all times toward the web 1 by the leg part 17a thereof. The pressurizing mechanism of the sensor 11 is thus constituted so that the spacing can be measured while the sensor is moved by following up to the deformation on the web side 2a of the roll 2.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Applicability Meter) The present invention relates to a coating device, and more particularly to a coating device equipped with an optical displacement sensor.

(Technical background) As described in Japanese Patent Application Laid-Open No. 51-3B737, for example, a coating device sprays gas at a predetermined pressure onto the web from an air bag roll to float the web, and while running the web in a non-contact state, Some types apply by forming beads of coating liquid on the surface.

In this case, the gap between the air bag roll and the web (floating ff1
) may vary. In addition, in devices equipped with a negative pressure chamber to facilitate the formation of beads of coating liquid, if the gap between the side wall of the negative pressure chamber and the web changes, the pressure in the negative pressure chamber will be affected and the upper surface of the bead will The difference in air pressure between the bottom side and the bottom side may change, causing the web to fluctuate.

(Problems to be solved by the invention) Due to these reasons, coating unevenness with streaks in the width direction may occur. In particular, in the case of silver halide photosensitive materials, uniform coating with a film thickness of several tens of microns is required, which is undesirable because it induces sensitivity fluctuations, etc.
There is a need for high productivity, stable and uniform coating, and a need to prevent defective products from being distributed to users.

For this reason, the inventors conducted extensive research to prevent the occurrence of coating unevenness that causes streaks in the width direction, and by measuring the gap between the air back roll and the web, they can accurately determine fluctuations in the running state of the web. If possible, it will be possible to control the IIJ to prevent web fluctuations using this measurement information, and furthermore, by analyzing the measurement information, the cause of web fluctuations can be known, and the occurrence of coating unevenness can be effectively dealt with. We have found that it is possible to do this, and also that product management becomes reliable and the occurrence of defective products can be prevented.

However, the coating liquid applied to the web has a temperature of around 30°C, and the web side of the airbag roll may be slightly deformed due to the influence of this heat. It was found that the measurement surface of the optical displacement sensor was misaligned, which adversely affected the measurement of the gap between the web and the airbag roll.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a coating device that reduces the influence of deformation of the air bag roll as much as possible and enables accurate web position measurement.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention injects gas from an airbag roll onto a running web, supports the web in a non-contact state, and applies the air to the surface of the web. In a coating device that forms and applies a bead of coating liquid, the airbag roll is equipped with an optical displacement sensor that irradiates light onto the web and measures the gap between the web and the airbag roll, and the optical displacement sensor It is characterized in that it is movably pressed and held via a suppression mechanism following the deformation of the airbag roll.

(Function) In the present invention, the airbag roll is equipped with an optical displacement sensor that measures the gap between the web and the airbag roll by irradiating light onto the web.

When the air bag roll is deformed due to the influence of the coating liquid applied to the web, this optical displacement sensor is moved by a pressing mechanism to follow the deformation. Therefore, the positions of the measurement surface of the airbag roll and the measurement surface of the optical displacement sensor do not deviate, so even if the airbag roll is thermally deformed, it will not have an adverse effect on the measurement of the gap between the web and the airbag roll. can be added.

(Example) Hereinafter, the coating device of the present invention will be explained based on a specific example shown in the accompanying drawings.

FIG. 1 is a schematic diagram of a coating apparatus of the present invention.

In the figure, reference numeral 1 denotes a web which is a support to which a coating liquid is applied, and is conveyed at high speed via an air bag roll 2. This air bag roll 2 is formed with injection holes 2a, and air at a predetermined pressure inside the air bag roll 2 is blown onto the web 1 from the injection holes 2a, so that the web 1 is supported in a non-contact state. There is.

A coating liquid supply device 3 is located close to the air bag roll 2, and a flow pump 5a is installed in the liquid supply paths 4a and 4b.
, 5b, different types of coating liquids are supplied. In this embodiment, two types of coating liquids are supplied, but one or more types may be used. Vertical narrow slits 6a, 6b are formed above the liquid supply channels 4a, 4b, and the coating liquid flows out onto the sliding surface 7 of the coating liquid supply device 3 through these slits 6a, 6b. This sliding surface 7 is inclined toward the air bag roll 2, and the coating liquid that flows out flows down in a layer and is applied to the web 1 from the lower end of the sliding surface 7. A bead 8 of coating liquid is formed between the web 1 and the web 1 .

A pressure adjustment box 9 is provided on the lower surface side of the bead 8, and the pressure adjustment box 9 reduces the air pressure on the lower surface side to press the bead 8 from above to below to ensure coating.

Various solutions are used for this coating solution, but in particular, a wood-philic colloid solution for photographic light-sensitive materials, such as a wood-philic binder such as gelatin or polyvinyl alcohol, and a viscosity of 4.
Suitable for low viscosity coating compositions of ~40 cp. Also,
Evaporation of the coating phase liquid containing a volatile solvent on the slide surface can be suppressed by applying positive pressure.

Further, as the web on which the above-mentioned wood-philic colloid solution is applied, a support for photographic light-sensitive materials such as a plastic film such as polyethylene terephthalate, triacetyl cellulose, or polypropylene or paper or the like is used.

A back layer 10 is formed on the side surface of the air bag roll 2 of the web 1, and a silver halide photographic light-sensitive material may be applied to both sides of the web 1 coated with the coating liquid in this manner.

An optical displacement sensor 11 is provided inside the airbag roll 2, and a distance 11i between the web 1 and the airbag roll 2 is provided.
L is measured near the area where the bead 8 of the coating liquid is formed.

The optical displacement sensor 11 is constructed as shown in FIGS. 2 to 6. That is, the support cylinder 12 of the optical displacement sensor 11 is attached to the airbag roll 2 in a direction perpendicular to the axis, and the tip i portion 12a of the support cylinder 12 is attached to the inner surface of the web side 2a of the airbag roll 2. A cap 13 is hinged to the rear end portion 12b.

The flange portion 13a of the cap 13 is applied to the side 2b of the airbag roll 2 opposite to the web 1 side via an annular elastic body 14 made of rubber, for example. As shown in FIG. 4, this cap 13 is screwed onto the airbag roll 2 by inserting a positioning screw 16 into the flange portion 13a of the cap 13 via a plate 15, and a plate spring is inserted between the positioning screw 16. A tightening screw 18 is inserted through 17, and is tightened and fixed to the air bag roll 2 by this tightening screw 18.

The leaf spring 17 has a pair of bent legs 17a,
When the tightening screw 18 is tightened with the foot portion 17a in contact with the plate 15, the foot portion 17a is bent, thereby applying a biasing force.

A predetermined gap S is formed between the flange portion 13a of the cap 13 and the outer surface of the airbag roll 2 when the elastic body 14 is tightened, and the plate spring 17 always moves the airbag roll 2 in the direction of the web 1. The biased support tube 12 is allowed to move. These constitute a pressing mechanism of the optical displacement sensor 11, and are suppressed and held movably following the deformation of the web side 2a of the air bag roll 2.

Therefore, when the coating liquid is applied to the web 1 by the coating liquid supply device 3, if the web side 2a of the airbag roll 2 is deformed due to the influence of the temperature of the coating liquid, the optical displacement sensor 11 follows this deformation. The support cylinder 12 moves. For this reason, the measurement surface of the air bag roll 2 and the optical displacement sensor 1
1 is reduced, and the measurement accuracy of the gap between the web 1 and the airbag roll 2 is improved.

Furthermore, a connector 20 for connecting the wiring 19 is fastened to the cap 13 with screws 21.

Inside the support tube 12 of the optical displacement sensor 11, a light source side unit 22 is provided on a support body 24 via a bracket 23, and this light source side unit 22 includes a semiconductor laser 25,
A projection lens 26 and a slit 27 are built-in. The wavelength of this semiconductor laser 25 is, for example, 780 nm, and the amount of light is also adjusted so as not to affect the coating liquid applied to the web 1. The light from the semiconductor laser 25 passes through the projection lens 26 and the slit 27 and enters the prism 28 constituting the entrance section. The light passes through the prism 28 again, is converged by the light receiving lens 29, and is input to the position detection sensor 30.

The prism 28 is thin with a large diameter in plan view, and is tightly engaged with the holder 31. This holder 31 is connected to the support tube 12 and the web side 2 of the airbag roll 2.
A is sealed and supported by O-rings 32 and 33 to ensure airtightness.

Therefore, even if the optical displacement sensor 11 is provided inside the air bag roll 2, the high pressure air inside the air bag roll 2 may enter from between the tip 12a of the support tube 12 and the web side 2a of the air bag roll 2. Also, the holder 31 of the prism 28
Since airtightness is ensured, leakage into the opening 2C of the air bag roll 2 and the inside of the support tube 12 is prevented.

The support body 24 is fixed to the holder 31 of the prism 28, and a fixing bar 34 having a flange 34a is screwed onto the receiving portion 24a of the support body 24, as shown in FIG. This fixing bar 34 is inserted into and supported by a support plate 35, and as the fixing bar 34 rotates, both are tightened and fixed in the proximal direction. Furthermore, printed wiring boards 36 and 37 on which drive circuits and control circuits for the semiconductor laser 25 and the position detection sensor 30 are provided are attached to the support body 24.

The position detection sensor 30 is supported by the sensor holder 3B, and the position detection circuit 39 detects the output state at the position of the light incident on the position detection sensor 30, and the detection signal is sent to the CRT 40.
Enter and display. The waveform displayed on this CRT 40 is shown in FIG. Does the optical displacement sensor 11 depend on the length of the airbag roll 2? In this embodiment, five pieces are arranged, and a to e in FIG. 7 show their arrangement positions. Further, a to e indicate the gap between the air bag roll 2 and the web 1, that is, a bead gap, and the amplitude at a to e indicates the amount of fluctuation of the web 1.

In FIG. 2, when the web 1 moves away from the left side, that is, from the airbag roll 2, the incident position of the reflected light on the position detection sensor 30 moves downward.

Furthermore, if the web 1 moves to the right and approaches the airbag roll 2, the incident position of the reflected light on the position detection sensor 30 moves upward. In accordance with the fluctuation of the web 1, the amount of fluctuation of the web 1 is displayed in the vertical direction in a to e of FIG. 7, and in this example, the fluctuation of the web 1 at positions d and a is getting bigger.

As this position detection sensor 30, a semiconductor device detection element (P
For example, a solid-state image sensor (CC) is used.
D) etc. Further, the position detection sensor 30 is moved by a position adjustment mechanism 41 according to the detected position of the web 1, so that the measurement range can be adjusted.

A cam plate 42 constituting this position adjustment mechanism 41 is rotatably supported by a receiving portion 24g of the support body 24 via a support pin 43. This cam plate 42 has a notch 4
2a is formed, and a bin 44 fixed to the sensor holder 38 is engaged with this notch 42a. Therefore, the position detection sensor 30 slides in the horizontal direction by the operation of the cam plate 42, and the movement of the cam plate 42 is performed by a pair of operation bars 45, 46. One end of the operation bar 45, 46 is connected to the support portion 24b of the support body 24.
, and abut on symmetrical positions of the cam plate 42 with the support bin 43 in between, and the other end is inserted through the support plate 35 . When either one of the operating levers 45, 48, for example, the right side is pushed, the cam plate 42 rotates to the left; when the left side is pushed, the cam plate 42 rotates to the right; The position detection sensor 30 is moved and the measurement position is adjusted.

The position detection sensor 30 is fixed by a position regulating bar 47, one end of which is inserted into a support portion (not shown) of the support body 24, and the other end is screwed onto a support plate 35. When rotated with a tool from the end side, the tip presses the sensor holder 38 to regulate the position.

(Effects of the Invention) In the present invention, the airbag roll is equipped with an optical displacement sensor that measures the gap between the web and the airbag roll by irradiating light onto the web, and this optical displacement sensor Since the optical displacement sensor is pressed and held so that it can move following the deformation of the back roll, when the air back roll deforms due to the influence of the coating liquid applied to the web, the optical displacement sensor uses a pressing mechanism to follow the deformation according to this deformation. Moving. Therefore, the positions of the measurement surface of the airbag roll and the measurement surface of the optical displacement sensor do not deviate, so even if the airbag roll is thermally deformed, it will not have an adverse effect on the measurement of the gap between the web and the airbag roll. This improves measurement accuracy.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the coating device of the present invention, Fig. 2 is a cross-sectional view of an optical displacement sensor, Fig. 3 is a longitudinal sectional view of the optical displacement sensor, and Fig. 4 is a side view of the optical displacement sensor. FIG. 5 is a partial perspective view showing the state in which the cap is attached, FIG. 6 is a sectional view taken along the line vr-Vl in FIG. 3, and FIG. 7 is a diagram showing measured waveforms. In the figure, 1 is a web, 2 is an air bag roll, 3 is a coating liquid supply device, 8 is a bead, 9 is a pressure adjustment box, 11
is an optical displacement sensor, 13 is a cap, 14 is an elastic body,
17 is a leaf spring, and 18 is a tightening screw. Figure 1 Figure 6 Figure 7

Claims (1)

[Claims] In a coating device that injects gas from an air back roll onto a running web, supports the web in a non-contact state, and forms beads of a coating liquid on the surface of the web for coating, the web is irradiated with light to form a coating liquid on the surface of the web. The airbag roll is equipped with an optical displacement sensor that measures a gap with the airbag roll, and the optical displacement sensor is held pressed so as to be movable following the deformation of the airbag roll via a pressing mechanism. Characteristic coating equipment.