JPH0533868U - Companion flow breaker - Google Patents

Abstract

(57) [Summary] [Purpose] To secure a stable jet of coating material applied to the web that is wound around a backing roll and conveyed. In a coating device for forming a paint layer by spraying a paint 4 from a paint supply device 3 onto a web 2 wound around a backing roll 1 and conveyed, an upstream side of the supply device 3 in the conveyance direction of the web 2 On the side, a device for forming a jet stream that flows in a direction opposite to the conveying direction of the web 2 is provided without contacting the web 2 and the paint supply device 3,
It is designed so that the air entrained in is shut off.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an entrained flow blocking device applied to a coating device.

[0002]

[Prior Art]

 FIG. 5 shows a schematic side sectional view of a conventional coating apparatus. In the figure, the web 2 conveyed from the paper feed section is conveyed on the backing roll 1 and coated with the coating liquid 4 blown out from the paint supply head 3, and then the finishing blade 5 is used to obtain a predetermined film thickness. The excess coating liquid is scraped off and transported to the drying process. Further, a wake blocking device 10 having a slit nozzle 12 for ejecting a jet stream facing the web is installed upstream of the coating material supply head in the web conveying direction so as to block the boundary layer developed on the surface of the web.

[0003]

[Problems to be solved by the device]

 In conventional coating equipment, as the web speed increases, the boundary layer developed on the web before coating becomes thicker. Therefore, the air film between the coating liquid 4 and the web 2 blown out from the coating supply head 3 becomes thick, the surface of the coating liquid is disturbed, and an air layer enters unevenly between the coating liquid 4 and the web 2. For this reason, the amount of the coating liquid 4 adhered becomes uneven in the width direction of the web 2, and the thickness of the coating layer 6 becomes uneven, which causes a problem such as deterioration of product quality. Therefore, even in the conventional device, the wake blocking device 10 is provided as shown in FIG. 5, but when the jet jet from the slit nozzle 12 collides with the web, the air flow becomes as shown by the arrow 13. Since the flow also flows to the right side in the figure as 13 ', the effect of wake blocking was insufficient. Further, when a large amount of the coating material 4 is jetted out, excess coating material flows out in the direction of the flow from the shutoff device 10, and there is a problem that dirt or clogging of the slit is caused on the slit nozzle 12. .. The present invention is intended to solve the above conventional problems.

[0004]

[Means for Solving the Problems]

 Therefore, the present invention is a coating device for forming a paint layer by spraying paint from a paint supply device onto a web wound around a backing roll and conveyed, and the web is provided upstream of the supply device in the web transfer direction. In addition, a device that forms a jet stream that flows in the opposite direction to the web transport direction is provided in a non-contact manner with the paint supply device, and a device that shuts off the air entrained in the web is provided. It is a means to

[0005]

[Action]

 Since the device that shuts off the air does not contact the web or the paint supply device, excess paint is ejected, and even if the excess paint turns behind the supply device, it does not reach the slit nozzle 8. Therefore, the slits are not clogged and dirt is not generated, and maintenance is easy. Further, the jet flow ejected from the slit nozzle sucks the air in the space formed by the supply device and the blocking device as a secondary flow due to the Coanda effect and the ejector effect, and does not directly collide with the web. There is no air flow to the air, and the effect of blocking the wake is much greater than that of the conventional one. Therefore, according to the present invention, since the entrained flow developing device sufficiently blocks the entrained flow developed on the web, an air layer is not formed between the web and the coating liquid even when the web speed is high, Transfer film thickness is constant.

[0006]

【Example】

 Hereinafter, the present invention will be described with reference to the embodiments of the drawings. FIGS. 1 and 2 show first and second embodiments of the present invention. First, in FIG. 1, 1 is a backing roll, 2 is a web, 3 is a paint supply device, 4 is paint, 5 is a blade, and 6 is adhered paint. Now, the air blown from the blow-out slit 8 at a flow velocity similar to the web velocity runs along the outer wall of the device 7 which blocks the entrained flow by the Coanda effect, along with the air downstream of the paint as a secondary flow. It is discharged only in the direction opposite to the direction. In this case, the blowing speed can be controlled within the range of 5 to 100 m / s. In the embodiment of FIG. 1, in order to blow the blown air so as to be parallel to the web surface aiming at increasing the accompanying flow blocking effect, another slit 9 is blown out from the rear portion of the device 7. By the Coanda effect, the direction of the air flow 20 along the outer wall of the device 7 is opposed to the direction parallel to the traveling direction of the web on the roll. As a result, even if the device 7 is attached to the web 2 on the roll at an angle α, it is possible to create a flow that is parallel and opposite to the web running direction. Further, the slit 9 enhances the Coanda effect, and even if the slit 9 is not provided, the accompanying flow blocking effect is far greater than that of the conventional one.

Next, FIG. 2 shows a second embodiment, in which the air blown out from the blowout slit 8 is also in the back portion of the paint supply device 3 and the air in the space 21 formed by the entrained flow blocking device 7 due to the ejector effect. With it, it is discharged in a direction parallel to and parallel to the web running direction. The slits 8 and 9 are provided so as to form a uniform gap in the width direction, and blown air is introduced from both ends of the blocking device 7 and the center of the lower part of the blocking device 7, From 9, it is possible to ensure uniform blowing in the width direction.

[0008]

[Effect of the device]

 As described in detail above, according to the present invention, the entrained air that develops in the web that is wound around the backing roll and conveyed is blocked, so that the jet flow of the paint is not disturbed even at high speed, and the coating liquid adheres. The amount is also uniform in the width direction. In addition, the air behind the jet paint is also discharged as a secondary flow, so a stable jet is secured. FIG. 3 shows a schematic diagram of the relationship between the air layer immediately after the conventional jet paint is transferred to the web and the transferred film thickness. At a speed of 2000 m / min, most of it becomes an air layer, making it difficult to control the paint film thickness. On the other hand, when the present invention is implemented, as shown in FIG. 4, the air layer does not increase with respect to the change in speed, and it is possible to obtain a sufficiently stable transfer even at 2000 m / min and control the film thickness. can do. In addition, since the present invention has a non-contact device for shutting off the air entrained in the web, the excess paint from the feeding device does not directly contact the shut-off device, and the slits are clogged or soiled by the paint. Can be prevented.

[Brief description of drawings]

FIG. 1 is a side sectional view of an entrained flow cutoff device according to a first embodiment of the present invention.

FIG. 2 is a side sectional view of an entrained flow blocking device according to a second embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a relationship between a conventional transfer film thickness and a web speed.

FIG. 4 is an explanatory diagram showing a relationship between a transfer film thickness and a web speed according to the present invention.

FIG. 5 is a side sectional view of a conventional coating apparatus.

[Explanation of symbols]

 1 Backing Roll 2 Web 3 Paint Supply Device 4 Paint 5 Finishing Blade 6 Adhering Paint 7 Entrained Flow Blocking Device 8 Air Blowing Slit 9 Air Blowing Slit

Claims (1)

[Scope of utility model registration request] 1. A coating device for forming a paint layer by spraying paint from a paint supply device onto a web wound around a backing roll and conveyed, wherein the web and the web are provided upstream of the supply device in the web conveyance direction. An entrainment flow interrupting device, which is provided with a device that forms a jet flow that flows in a direction opposite to the transport direction of the same web in a non-contact manner with the paint supply device, and shuts off the air entrained in the web.