JPH05208160A - Coating device - Google Patents

Abstract

(57) Abstract: The present invention is directed to the full width of a material web or generally the surface to be coated, even when the distance between the receiving chamber of the coating material and the surface to be coated is relatively short. The aim is to provide a uniform and even flow of coating material over the entire width of the. In the supply channel, an obstruction strip is formed in the longitudinal direction of the doctor element in parallel with it, or ribs and grooves are formed alternately in the longitudinal direction of the doctor element, or these Providing a plurality of rows of interfering strips, each abutting each other, provided with a plurality of projections corresponding to ribs, or a continuous row of strips having a series of holes, by means of the interfering strips or a plurality of projections The cross-sectional area ratio of the front and rear supply channels is reduced by at least 30%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention is used for applying applicator devices according to the preamble of claim 1, namely a doctor element for metering the applicator substance in a flat and even manner, and containing fresh applicator substance. And a receiving chamber extending along the support beam of the applicator, in each case having a length approximately equal to the doctor element, in which case also a supply passage of the same length is arranged. , A coating device of the type in which the coating material is supplied by this supply channel to a coating web which is formed along a material web or a corresponding roll used for guiding the material web.

[0002]

2. Description of the Prior Art Application devices of this kind are already known, for example German patent application DE 37255.
No. 45 publication. In this known example,
The receiving chamber for containing the coating substance is placed in the immediate vicinity of the object to be coated (the roll surface or the web surface guided by the roll), and the distance from the receiving chamber to the treatment surface is The significant reduction has the advantage that the applicator itself can be made relatively compact. German Utility Model Registration No. 9106311 also discloses another device similar to the above-mentioned coating device, in which the coating substance is usually pressurized in its receiving chamber and has a relatively narrow width. Is guided through the passage to the surface to be coated. Therefore, this system is also called a nozzle type coating mechanism.

[0003]

It is an object of the present invention that the flow of the coating material flows through the material web even when the distance between the receiving chamber for the coating material and the surface to be coated is relatively short. The point is to ensure that the supply is perfectly even over the entire width or generally the surface to be coated. In this case, if all other prerequisites that make the coating device a highly practical device are satisfied,
To achieve the intended purpose, it is only necessary for the product to be finished (paper or cardboard) to be subjected to a very homogeneous coating treatment. However, according to the usual processing techniques of today, the surface to be coated is operated at a very high speed and is forced to reach the doctor element, so that the unevenness of the coating material stream that has occurred up to that point has occurred. Such a non-uniform portion will eventually remain until the end, even if countermeasures are taken as necessary to remove it.

[0004]

According to the measure of the invention proposed for solving the above problems, an obstruction strip is formed inside the supply channel in the longitudinal direction of the doctor element and parallel thereto. A plurality of rows of obstruction strips, each of which is provided with or is alternately formed in the longitudinal direction of the doctor element, or with a plurality of projections corresponding to these ribs, but abutting each other, is provided. Or a continuous row of strips with a series of holes is provided, these interfering strips or projections providing a cross-sectional area ratio of the feed passages located before and after it of at least 3
0% is configured to be reduced.

In a preferred embodiment of the applicator according to the invention, the series of obstructing strips (grooves), ie, the grooves and the ribs, are different from each other in order to produce an even flow over the width of the feed channel. Interference strips are provided that are adapted to local conditions.

[0006]

The turbulent flow formed through the projections or ribs of the disturbing strips, combined with the additional flow resistance created by the disturbing strips or projections, makes the coating material even more effective. It has the effect of equalizing.

[0007]

The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings.

A support beam, generally designated 1 in FIG. 1, is used to carry a major part of the coating apparatus.

A feature of this embodiment is that the support beam 1 is supported adjustable over its entire length in order to compensate or offset the deflection of the support beam 1 or to set its deflection characteristic to a predetermined value. The support sleeve 13 is movably mounted via a pressure tube 14 supported on the central support pipe 12. A doctor element 5 is tensioned (tightened) in a fixed position on the support beam 1 on the outflow side with respect to the surface to be coated.

In the present invention, even if the surface to be coated is, for example, roll C, or this roll C
It may be a material web W (in particular paper or cardboard) which is guided through and moves in the direction indicated by the arrow 50 in FIG.

Another beam structure 2 is held on the support beam 1 via ribs 33, and the beam structure 2 is mainly composed of the following elements.

First of all, the receiving chamber 26 in the form of a pipe is first mentioned. The receiving chamber 26 has a plurality of outlet openings 27 distributed over its entire length. It is guided to the supply passage 18 via these outlet openings 27.

The next component is the guide block 16, which limits the supply passage 18 on one side and at the same time the passage 23 along the surface to be coated, and on the other side. Also limits the discharge passage 8 for delivering excess coating material scraped off by the doctor element 5 from the surface to be coated. The discharge passage 8 is connected via a throttling portion 10 to a collection trough 29 for collecting the applied substance.
In the area of the guide block 16, along this discharge passage 8, i.e. in the longitudinal direction of the doctor element 5, an obstruction strip 6 is provided, the rib of which, for example, is shown in FIG. It rushes into the passage 18. The obstruction strip 6 also narrows the free passage cross section in the supply passage 18.
The damming strip 4 carried by the receiving chamber 26 limits the supply passage 18 along the surface to be coated on the inlet side relative to the surface to be coated. At this point, even if a slight amount of excess coating substance is present, the guide plate 20
Is guided downward in the direction of the arrow and is fed into the collection trough 29.

The passages 23 formed by the guide block 16 along the surface to be coated may be constructed as relatively narrow passages in order to further equalize the flow of the coating substance.

In the embodiment shown in FIG. 2, the interference strip 6 is provided with a plurality of projections between which the groove 1 is provided.
5 is formed. In this case, the protrusion and the groove 15 are both formed as a rectangular groove. In the embodiment shown in FIG. 3, the base of the groove 7 located between the ribs 9 provided on the interference strip 17 'is formed in an arc shape.
In other parts, these grooves and ribs are formed with a fairly acute angle so as to generate turbulence. In this particularly advantageous embodiment of the invention shown in FIG. 3, a series of interfering strips 17 ', 1 directly butted against each other is provided.
7 ", 17 '" have different grooves 7, 7', 7 "and ribs 9, 9 ', 9" on each strip, and these blocking strips are best used. Since another groove or another similar strip having a groove shape can be used to obtain the above flow condition, the guide block 16 (or the groove for holding the obstructing strip) can be provided over the entire length. It makes it possible to create optimized coating material flow cross sections.

Interfering strip 17 according to the embodiment shown in FIG.
Is provided with a plurality of perforated portions 3 and 3'over its entire length, and in this case, the diameter of one perforated portion 3'is set to a value smaller than the diameters of many perforated portions 3. .. Therefore, according to this embodiment, it is possible to appropriately change the pressure loss in the turbulent flow over the entire length of the obstruction strip in order to further equalize the flow state as needed. This is also evident from the obstruction strips shown in FIG. 3, in which the grooves 7 ', 7''are arranged with a relatively short mutual spacing, respectively, or
Since the grooves are formed as shallower grooves, ribs 9'and 9 '' having different shapes are formed between the grooves. The obstruction strip 6 ″ according to another embodiment of the invention shown in FIG. 5 is provided with a triangular groove 19.

In this embodiment, one or more interfering strips are inserted laterally into the guide block 16,
It is desirable to hold within this guide block 16 using the fitting 31 shown in FIG. 1 or a similar guide member.

In each of the embodiments shown in FIGS. 2 to 4, the vertical width of the supply passage 18 is represented by the symbol s. In this case, the obstruction strip and its ribs and grooves are as follows. It is desirable to satisfy the following conditions. That is to say, in principle, the flow cross section of the coating material is approximately 10 mm to 2 which is located immediately before or after the obstruction strip.
The narrowing is about 35% to 70% of the vertical cross section of 0 mm width. Further, in this case, each rib 9,
The height dimension such as 9 ′, 9 ″ is preferably 30% to 30% of the width s in the supply passage 18 (ie 3 mm to 7 mm, for example).
To a value equivalent to 45%, and also grooves 7, 7 ', 7'', 15
The maximum width of each is set to a value corresponding to 25% to 45% thereof. When the shape of the groove is significantly deviated from the rectangular shape, these set values are defined based on the average width of the groove. The ratio between the groove width and the width at the free ends of the ribs is preferably set to a value between 0.85 and 1.45. The rib thickness in the flow direction is 8 mm to 15 mm
However, the thickness at the free end of the rib must also not be below its minimum value. The grooves (cutouts) and ribs in the interference strips are designed to have a relatively angular shape as already mentioned, but in order to create turbulence anyway, these corners Must not be rounded and chamfered. Also in the obstruction strip 17 according to the embodiment of FIG.
Cross section of the 3 'is set to a value of 15mm ² ~40mm ^2.

By the way, the groove of the obstruction strip according to the invention can be constructed in a shape which is significantly different from that shown, and it is also possible to use a groove of considerably complicated shape if required. What is possible is, of course, obvious, not to mention further, and this measure does not depart from the basic consideration underlying the invention.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an applicator according to the present invention cut perpendicular to the direction of motion of the surface to be coated.

FIG. 2 is a longitudinal sectional view of one or more interfering strips and their grooves and protrusions according to an advantageous embodiment of the application device of the invention, taken perpendicular to the plane of the drawing.

FIG. 3 is a longitudinal sectional view of one or more interfering strips and their grooves and ribs according to an advantageous embodiment of the application device of the invention, taken perpendicular to the plane of the drawing.

FIG. 4 is a longitudinal sectional view of one or more obstructing strips and their holes and ribs according to an advantageous embodiment of the applicator of the invention, taken perpendicular to the plane of the drawing.

FIG. 5 is a plan view showing still another embodiment of the interference strip according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Support beam, 2 ... Beam structure, 3, 3 '... Perforation part, 4 ... Damming strip, 5 ... Doctor element, 6, 6' ... Interference strip , 7, 7 ', 7' '... Groove, 8 ... Ejection passage, 9, 9', 9 '' ... Rib, 10 ... Throttling part, 12 ... Support pipe, 13. ..Supporting sleeves, 14 ... Pressure tubes, 15 ... Grooves, 16 ... Guide blocks, 17, 17 ', 17' '... Interfering strips, 18 ... Supply passages, 19 ...・ Groove, 20 ... Guide plate, 23 ... Passage, 26 ... Receiving chamber, 27 ... Exit opening, 29 ... Collection trough, 31 ... Joint, 33 ... Rib , 50 ... arrow indicating the direction of movement of the surface C ... roll, s ... vertical width in supply passage, W ... material c Breakfast.

Claims (10)

[Claims] 1. A doctor element (5) for evenly leveling the coating substance and a support beam (1) used in the coating device for containing fresh coating substance.
With a receiving chamber (26) extending along it, and in each case having a length approximately equal to the doctor element (5), and in this case also a supply channel (18) of the same length.
Through which the coating substance is supplied to the coating space (23) formed along the material web or the corresponding roll (C) used for guiding the material web. In the coating device of the type described, a doctor element (5) is provided inside the supply passage (18).
With interfering strips (6) formed parallel to it in the longitudinal direction of the ribs, or with ribs (9, 9 ', 9'') formed alternately in the longitudinal direction of the doctor element (5) A plurality of rows of interfering strips (17 ', 1), each abutting one another, with grooves (7,7', 17 '', 15,19) or with projections corresponding to these ribs.
7 ", 17 '") or a continuous row of strips (17) with a series of holes (3,3')
Are provided, in which case the blocking strips (17 ', 1
7 ″, 17 ′ ″) or a plurality of protrusions are configured to reduce the area ratio in the cross section of the supply passage (18) located before and after the protrusion by at least 30%. .. 2. Grooves (15, 19, 7, 7 ', 7''),
The ribs (9, 9 ', 9'') or holes (3, 3') have locally different shapes to change the resistance caused by the ribs (9, 9 ', 9''). The coating device according to claim 1, wherein the coating device is configured as follows. 3. A series of interfering strips butted against each other such that the ribs (9, 9 ', 9'') or grooves (7, 7', 7 '') have different shapes and / or sizes. The coating device according to claim 1 or 2, characterized in that a piece (17 ', 17'',17''') is provided. 4. Ribs (7, 7 ', 7'') project into the remaining free flow cross section in the feed passage (18) and have an average width of 30 in the feed passage (18).
In the longitudinal direction of the doctor element (5) at the free end of the groove (15,7,7 ', 7''), measured in the width direction of the passage, corresponding to a value between% and 45%. While having a width dimension corresponding to a value between 0.85 times and 1.45 times the measured groove width, the groove (15, 7,
7 ', 9'') or the intermediate spaces between the projections corresponding to these grooves are also the same, corresponding to values between 25% and 40% of the average vertical width in the feed passage (18). The coating apparatus according to any one of claims 1 to 3, wherein the coating apparatus has a width dimension measured as described above. 5. The groove according to claim 1, characterized in that the groove (7, 7 ′, 7 ″, 15) is formed as a groove having a shape with a substantially consistent width. Coating equipment. 6. The coating apparatus according to claim 5, wherein the bottom surface of each groove is chamfered. 7. The coating apparatus according to claim 1, wherein each groove is formed in a triangular shape. 8. Application device according to claim 1, characterized in that the blocking strip (17) has a series of round holes. 9. Ribs (7, 7 ′, to be coated)
The coating device according to any one of claims 1 to 8, characterized in that the distance between the edge closest to the surface of 7 '') and this surface is set to a value of at most about 110 mm. 10. A plurality of obstruction strips (6, 6 ', 17) or a plurality of rows of obstruction strips (17, 17', 17 '', 1).
Application device according to any one of the preceding claims, characterized in that 7 ''') is arranged such that it can be inserted into a flute formed in the application device.