JP3251907B2 - Vacuum coating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-reducing coating apparatus, and more particularly, to a uniform coating of an object to be coated having various uneven surfaces such as horizontal grooves and deeply carved patterns irrespective of the surface shape. The present invention relates to a reduced-pressure coating apparatus capable of performing the above.

[0002]

2. Description of the Related Art Conventionally, an apparatus 21 shown in FIG. 6 has been used as a vacuum coating apparatus for a long object such as a ceramic outer wall material. In this case, the coating chamber 22 is placed under reduced pressure, and when the object to be coated passes through the coating chamber from the entrance opening 22b to the entrance opening 22a, the coating is unevenly coated by contacting an air flow containing a large amount of paint particles. However, the excess paint is squeezed and removed by the air flow (so-called air knife) into the coating chamber generated in the slit formed between the outlet opening 22a and the workpiece.

[0003] However, since this air flow flows along the surface of the object to be coated from the longitudinal direction thereof, the surface of the object to be coated is flat, or only the longitudinal grooves (longitudinal grooves) are formed. If
Even though the paint is applied evenly, if there are horizontal or diagonal grooves or deep carved patterns, the excess paint in the grooves will not be sufficiently ironed, and the excess will remain there, There was a difficulty that was not painted. The non-uniform amount of paint applied causes cracking of the coating film upon drying, which is a serious defect as a coated product.

To improve this, as shown in FIG. 7, the outlet opening of the coating chamber 22 is formed as a cylindrical portion 23 extending over the object 24 to be coated, and the edge of the cylindrical portion is covered. There is disclosed an inclined edge crossing the traveling direction of the coated body 24, which generates an airflow that partially flows in the lateral direction as well as the longitudinal direction of the coated body (actually disclosed in Japanese Unexamined Utility Model Publication No. 1235
No. 76), the improvement of the uniform paintability for the case where there is a horizontal groove or a diagonal groove or for a deeply carved pattern was not sufficient.

As shown in FIG. 6, the conventional vacuum coating apparatus is provided with a paint collecting box 25 having a baffle plate 25b and a filter 25a to collect paint and use it for circulation. (Not shown), the paint on the wall of the collection box 25 was dried and accumulated, or the filter 25a was clogged, and the operation could not be performed for a long time. Further, the foaming of the paint in the collection box 25 was severe, and when this paint was sent to the coating room 22 by the pump P and reused, the foam adversely affected the finish of the coating surface of the object to be coated.

[0006]

Therefore, first, the present invention relates to a method for uniformly coating an object to be coated having various uneven patterns such as a horizontal groove and a deeply carved pattern irrespective of its surface shape. Second, to provide a reduced-pressure coating apparatus capable of performing accurate coating. Second, it is possible to operate for a long time without problems of accumulation of paint on the wall of the paint collection container and clogging of the filter. It is an object of the present invention to provide a reduced-pressure coating apparatus in which the foaming of the paint is small and the adverse effect on the finish of the coated surface is not caused.

[0007]

As a result of intensive studies to achieve the above object, the shape of the outlet opening is made to have a slope crossing the direction of travel of the object to be coated, and In addition to the air flow along the surface, it is possible to efficiently remove excess paint in the lateral grooves and deep grooves by actively generating an air flow that flows in from the vertical direction, and if a cyclone is used as a paint circulation means, The present inventors have found that the problems of the accumulation of paint, clogging of a filter, and foaming of paint can be solved, and the present invention has been completed.

That is, the invention according to claim 1 of the present invention has a means for transporting a workpiece to be transported in a coating chamber through an entrance opening, and when the workpiece is passed, the opening and the workpiece are connected to each other. In a reduced pressure coating apparatus provided with a coating chamber that forms a gap between the coating body and a decompression unit for reducing the pressure in the coating chamber, the shape of the outlet opening is changed in the traveling direction of the object to be coated. On the other hand, in addition to having an intersecting inclined portion, in the vicinity of the outlet opening, a covering member for the object to be coated constituting a slit from the vertical direction and a slit from the horizontal direction with respect to the surface of the object to be coated is provided. It is a reduced pressure coating device characterized by the following.

Here, the "shape of the outlet opening" refers to a horizontal cross-sectional shape of the coating chamber when the coating chamber is viewed in a plan view (hereinafter, simply referred to as a plan view). In this case, it is sufficient that at least a part has an inclined portion, and a case where the entire opening is inclined at a certain angle is also included. In addition, since it is sufficient that at least a part has an inclined portion, the entire opening may be a W, V, or zigzag type, and a part of the opening may have such a shape. The shape of these outlet openings can be selected optimally according to the surface shape of the object to be coated. It is a matter of course that, for the side wall portion including the outlet opening, a member different from the other side wall member may be used to configure the shape of the outlet opening.

The vertical slit formed near the outlet opening may be formed on the covering member, and the slit is formed between the coating chamber outlet side end of the covering member and the coating chamber side wall. May be. In this case, the shape of the slit in plan view is preferably the same as or similar to the shape of the opening. Further, it is preferable that the shape of the exit side end of the slit from the horizontal direction as viewed in plan is the same as or similar to the shape of the exit opening.

The slit from the vertical direction only needs to be formed at a position perpendicular to the surface of the object to be coated. It is preferable that the respective angles of the two slit constituting walls be 45 ° to 135 ° with respect to the surface of the object to be coated. However, in this case, both constituent walls do not necessarily have to be at the same angle. More preferably,
It is preferable that the angle of the slit constituting wall on the side of the coating room is 90 °, and the angle of the other constituting wall is 45 ° to 90 °. In addition, this slit configuration wall may be configured to have an appropriate width as needed.

With the above construction, not only the air knife from the horizontal direction flowing along the surface from the length direction but also the air knife from the vertical direction on the surface of the object to be coated is generated. As a result, the excess paint in the groove is subjected to almost the same ironing irrespective of the direction and depth of the groove, and the effect of both knifes is combined, regardless of the surface shape of the object to be coated. And a more uniform coating than before is possible.

Here, the adjustment of the effect of the air knife from the horizontal direction and the effect of the air knife from the vertical direction can be achieved by adjusting the interval and the width of the slit through which the air flow as its source passes. For example, when only a horizontal slit width is different and a device having the same slit interval, vertical slit width, and other configurations is compared, a device having a larger horizontal slit width has a larger airflow flowing from the horizontal direction. , The amount of airflow flowing from the vertical direction increases, and the air-knife effect from the vertical direction increases.

[0014] The invention according to claim 2 of the present invention is characterized in that, on the outlet side wall of the coating chamber, the side wall portion including the outlet opening is recessed in the direction of the inlet side wall. It is a reduced-pressure coating device of the description. Also in this case, it is a matter of course that the side wall portion including the outlet opening may be depressed in the direction of the inlet side wall by using a member different from the other side wall members.

[0015] With this configuration, when conveying the object to be coated such as a ceramic long object using the conveying means such as a conveyor belt, the installation interval of the roll for supporting the object to be coated is set to
The length can be shorter than that having a convex side wall portion. As a result, for example, if the roll installation interval is long, the positional relationship between the slit and the object to be coated becomes unstable, and stable coating is difficult. Even if a roll is not provided in the room, stable conveyance can be ensured only by a roll provided outside the coating room.

According to a third aspect of the present invention, a cover member for the object to be coated is provided at the entrance opening of the coating chamber, and the member between the object to be coated and the cover member is provided when the object to be coated passes. The vacuum coating apparatus according to claim 1 or 2, wherein a slit having a width is formed.

With this configuration, a wide slit is formed by the covering member at the entrance opening, so that the inflow of air from the horizontal direction into the coating chamber is suppressed, and as a result, the covering member over the entrance opening is formed. As compared with the case without the above, the amount of inflow of air from the vertical direction is increased, and the air-knife effect from the vertical direction is enhanced.

According to a fourth aspect of the present invention, there is provided the reduced pressure coating apparatus according to the first, second or third aspect, wherein a coating circulation means using a cyclone is provided. Examples of the circulating means include means for connecting a pressure reducing device such as a blower to the cyclone and between the cyclone and the coating chamber by a pipe, and sending the paint separated by the cyclone to the coating chamber by a pump.

With this configuration, the paint that has entered the cyclone from the coating chamber is separated by the centrifugal force of the swirling flow. A situation in which the paint adhering to the filter does not dry and accumulate does not occur, and since no filter is required, the filter can be operated for a long time without a problem of clogging of the filter. Further, the amount of air bubbles generated in the cyclone is small, and even if the air bubbles are circulated in the coating chamber, the air bubbles do not adversely affect the finish of the coating surface.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing a main part of a vacuum coating apparatus according to a first embodiment of the present invention, wherein A is a longitudinal sectional view, and B and C are transverse sectional views.

In FIG. 1, reference numeral 2 denotes a coating room, 2b denotes an inlet opening, and 2a denotes an outlet opening. Each of the openings is formed by a side wall plate which is a member separate from the main body wall of the coating chamber. In particular, the outlet side opening 2a is formed at a position recessed inside the coating chamber.
In this case, the attachment of the separate member to the main body wall may be performed by known means such as screwing and bolting.

Reference numeral 3 denotes a member for covering the object to be coated. Reference numeral 4 denotes an object to be coated, which forms slits S2 and S3 from the horizontal direction between the entrance opening 2b, the exit opening 2a, and the cover member 3 when passing through the coating chamber. The covering member 3 forms a slit S1 from the vertical direction with the coating chamber outlet side wall. Adjustment of these slit intervals can be achieved by attaching the two members constituting the slits to a support so as to be freely opened and closed (for example, using a known long-hole nut and bolt).

As shown in FIG. 1B, the shape of the outlet side opening 2a in a plan view is inclined with respect to the advancing direction of the object to be coated, and the slit S1 and the cover member 3 from the vertical direction.
Has the same shape at the outlet end. In addition, each shape of these members with respect to the traveling direction of the object to be coated may be a U-shape as shown in FIG. 1C.

In this way, not only the air knife effect from the horizontal direction but also the air knife effect from the vertical direction are generated, and the slits S1 and S2 at the inlet of the air flow are formed on the object to be coated. The air knife is inclined not only in the longitudinal direction but also in the width direction of the object to be coated. It becomes possible to make the paint more uniform than before. Further, since the outlet opening is recessed, the interval between the rolls 6 supporting the object to be coated can be shortened as shown in FIG. 1A, as compared with the case where the outlet opening protrudes.

FIG. 2 is a schematic view showing a main part of a reduced-pressure coating apparatus according to a second embodiment of the present invention.
B is a cross-sectional view. FIG. 3 is a partially enlarged view of the vicinity of the entrance opening of FIG. 2A. As can be seen by comparing FIG. 2A and FIG. 1A, the device according to the second embodiment
In the apparatus of the embodiment, a cover member 3b is provided to extend to the entrance opening 2 to make the entrance side slit S3 wide, and a gap below the exit side slit S2 is provided by a separately provided cover member 3a. Is formed between the coating chamber outlet side wall which is recessed and the object to be coated, and the shape of the outlet side opening 2a in plan view, the shape of the vertical slit S1 and the outlet side end of the covering member 3a. As shown in FIG. 2B, the shape of the object is in the shape of a letter in the traveling direction of the object to be coated. The shape of each of these members with respect to the traveling direction of the object to be coated may be inclined as shown in FIG. 2C.

In this way, as shown in FIGS. 2 and 3, the slit S3 is made to have a proper width, and the air flow from the horizontal direction (a, b) , C, d) is suppressed, while the flow of the airflow (e) from the vertical slit S1 is increased, so that the vertical air-knife effect can be further enhanced as compared with that of FIG. It is possible to more effectively deal with lateral or oblique deep grooves.

FIG. 4 is a schematic view showing a main part of a reduced pressure coating apparatus according to a third embodiment of the present invention, wherein A is a perspective view of a coating chamber, and B is a cross-sectional view. In this case, the entire side wall of both the entrance and the exit is made the same as the shape of the exit side opening 2a in a plan view (shape), and the slit S1 from the vertical direction and the exit side of the coating room exit side covering member 3a. FIG. 4 shows the shape of the end and the entrance end of the coating chamber entrance side covering member 3b.
As shown in B, it has the same shape (shape) as the coating room outlet opening.

In this way, since there is no partial dent in the coating chamber, the coating material smoothly moves in the coating chamber and is also excellent in design. In order for the paint to move smoothly in the coating chamber, it is only necessary that there is no partial unevenness on the side wall of the coating chamber. Therefore, the shape of the inlet side wall in plan view is not necessarily the same as the shape of the outlet side wall. You don't have to.

FIG. 5 is a schematic view of a vacuum coating apparatus according to a fourth embodiment of the present invention, in which a cyclone is used as a paint collecting means, wherein A is a front view, B is a side view,
C is a plan view. In this case, the top of the coating chamber 2 is connected to the upper side wall of the cyclone 5, the bottom of the cyclone 5 is connected to the bottom of the coating chamber 2 via the pump 7, and the top of the cyclone 5 is connected to a blower (not shown). Are linked. Reference numeral 8 denotes a cover for the entrance opening, and its role will be described later.

In this way, the paint in the coating chamber 2 flows violently through the slits under a reduced pressure by a blower to form an air flow containing a large amount of paint, and flows out from the top of the coating chamber. The paint entering the cyclone 5 is efficiently separated by the centrifugal force of the swirling flow, so that not only the paint recovery rate is good, but also the paint adheres to the box wall as in the case of separation using a conventional paint recovery box. A situation in which the dried paint is dried and deposited does not occur. In addition, since no filter is required, the filter can be operated for a long time without a problem of clogging of the filter. In addition, using a cyclone,
The generation of air bubbles contained in the paint in the cyclone is extremely reduced, and even if this paint is circulated and used, there is no adverse effect on the finish of the coating surface due to the air bubbles when a conventional recovery box is used.

In the embodiment of the present invention, by incorporating a blending tank with an automatic viscosity adjusting device in the paint circulation system, it is possible to add paint and automatically adjust the viscosity during the painting operation. In other words, during the painting operation, the paint is continuously exposed to reduced pressure, so that the water in the paint evaporates,
The NV value (non-volatile component concentration) of the paint gradually increases,
If this automatic viscosity controller is incorporated, constant N
The V value can be secured, and long-time automatic operation can be performed.

Further, the tip of the object to be coated is detected at a predetermined position of the feed conveyor, and a cover (for example, 8 in FIG. 5A) provided at the entrance opening of the coating chamber is automatically opened. If the lid is automatically closed at the same time as the rear end of the object to be passed passes through the opening, the inflow speed of the air flow at the slit on the exit side of the coating chamber can be kept constant, so that the longitudinal direction of the object to be coated can be maintained. A uniform coating of the whole is ensured.

[0033]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

(Example 1) An apparatus having a coating chamber 2 shown in Fig. 1 and having a shape such as an outlet opening shown in Fig. 1C is connected to a cyclone and a blower as shown in Fig. 5. And painted under the following conditions. Coating object: cement-based outer wall material, length 3030 mm, width 470 mm, surface shape is 3 mm, 6 mm in depth, and grooves of 10 mm in width are formed at random intervals vertically and horizontally. Paint: Acrylic emulsion paint (non-volatile component concentration: 45% by weight, viscosity: 600 cps) The interval between slits S2 and S3 in FIG. 1; 5 mm; width of slit S2; Also, both constituent walls of the slit S1 from the vertical direction are perpendicular to the surface of the object to be coated, and the interval between them is 10 mm. Conveying speed by the conveyor; 40 m / min blower - pumping speed; 60m ³ / min

(Comparative Example 1) Using the reduced pressure coating apparatus shown in FIG. 6 described above, coating was performed under the following conditions. In this case, the shapes of the inlet and outlet openings are perpendicular to the traveling direction of the object to be coated in a plan view, and no slit is formed from the vertical direction as shown in the first embodiment. Workpieces, paints,
The conveying speed by the conveyor and the exhaust speed of the blower are the same as in the first embodiment.

(Comparative Example 2) The reduced pressure coating apparatus shown in FIG. 7 was used, and a paint collection box 25 shown in FIG.
Was arranged as shown in FIG. 6 and painted under the following conditions. In this case, the outlet portion of the object to be coated is a cylindrical portion 23 extending over the object to be coated, and the edge of the cylindrical portion is an oblique edge crossing the traveling direction of the object to be coated 24. Example 1
No slits are formed from the vertical direction as shown in FIG. The displacement of the object to be coated, the paint, the conveying speed by the conveyor, and the displacement of the blower are the same as in the first embodiment.

The coating was performed under the above conditions, and the following results were obtained.

[Table 1] Here, each symbol means the following. ；: Uniform coating without excessive paint remaining in grooves. X: Excess paint is mostly left in the groove, and the paint becomes uneven. Δ: intermediate state between ○ and ×. The average coating amount in a wet state was 80 to 100 in all cases.
g / m ² .

As shown in the above table, the uniform coating can be applied to the 6 mm deep lateral groove, which cannot be uniformly coated by the conventional apparatus, by using the reduced pressure coating apparatus of the present invention. It should be noted that, with respect to the vertical grooves, even with the conventional apparatus, no excessive paint remained in the grooves, and almost uniform coating was achieved.

[0039]

As described above, according to the first aspect of the present invention, air from the horizontal direction flowing along the surface from the length direction is applied to the surface of the object to be coated.
Since not only the knife but also the air knife from the vertical direction is generated on the surface at the same time, both knife effects are combined, and the excess paint in the groove is substantially reduced regardless of the direction and depth of the groove. The same ironing is applied, and almost uniform coating becomes possible irrespective of the surface shape of the object to be coated.

Further, according to the second aspect of the present invention, the installation interval of the roll for gripping the object to be coated can be made shorter than that of the roller having the convex side wall portion. as a result,
For example, if the interval between the rolls is long, the positional relationship between the slit and the object to be coated becomes unstable, and the coating of the object to be coated is unstable in maintaining the form, which makes stable coating difficult. Even if no roll is provided, stable transport can be ensured only by the roll provided outside the coating room.

According to the third aspect of the present invention, since a wide slit is formed by the covering member at the entrance opening, the inflow of air into the coating chamber from the horizontal direction is suppressed. As a result, the amount of air flowing in from the vertical direction is increased and the air-knife effect from the vertical direction is increased as compared with the case where the covering member is not provided at the entrance opening, and the lateral or oblique deep groove or the like Is more effective.

According to the fourth aspect of the present invention, since the paint entering the cyclone from the coating chamber is separated by the centrifugal force of the swirling flow, it is separated using a conventional paint recovery box. As in the case described above, a situation in which the paint adhered to the container wall is dried and deposited does not occur, and since no filter is required, there is no problem of clogging of the filter.
Long-term operation becomes possible. In addition, bubbles contained in the paint used in circulation are reduced, and the bubbles do not adversely affect the finish of the coating surface.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a main part of a reduced-pressure coating apparatus according to a first embodiment of the present invention, where A is a longitudinal sectional view, and B is
And C are cross-sectional views.

FIG. 2 is a schematic view showing a main part of a vacuum coating apparatus according to a second embodiment of the present invention, where A is a longitudinal sectional view, and B is
Is a cross-sectional view.

FIG. 3 is a partially enlarged view of the vicinity of an entrance opening of FIG. 2A.

FIG. 4 is a schematic view showing a main part of a reduced-pressure coating apparatus according to a third embodiment of the present invention, wherein A is a perspective view of a coating chamber, and B is a cross-sectional view.

FIG. 5 is a schematic view of a reduced-pressure coating apparatus according to a fourth embodiment of the present invention, in which a cyclone is used as paint collection means, where A is a front view, B is a side view, C
Is a plan view.

FIG. 6 is an example of a conventional vacuum coating apparatus.

FIG. 7 is another example of a conventional vacuum coating apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Decompression coating device, 2 ... Painting room, 2a ... Outlet opening, 2b ... Inlet opening, 3 ... Covering member of a to-be-coated body,
4 ... Workpiece, 5 ... Cyclone, 6 ... Roll, 7
... pump, 8 ... lid of inlet opening, S1 ... slit from vertical direction, S2, S3 ... slit from horizontal direction.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B05C 3/09-3/15 B05D 1/16-1/24

Claims (4)

(57) [Claims] 1. A coating chamber for conveying an object to be coated which is conveyed through a doorway through an opening in a coating chamber, wherein a gap is formed between the opening and the object to be coated when the object to be coated passes. And, in a reduced-pressure coating apparatus provided with a decompression means for decompressing the interior of the coating chamber, the shape of the outlet opening has an inclined portion that intersects with the traveling direction of the object to be coated. And a cover member for the object to be coated, comprising a slit in the vertical direction and a slit in the horizontal direction with respect to the surface of the object to be coated, near the opening on the outlet side. 2. The reduced pressure coating apparatus according to claim 1, wherein a side wall portion including the outlet opening is recessed in a direction of the inlet side wall in an outlet side wall of the coating chamber. 3. A coating member for covering an object to be coated is provided at an entrance opening of the coating chamber, and a wide slit is formed between the object to be coated and the covering member when the object to be coated passes. The reduced-pressure coating device according to claim 1, wherein the coating is performed. 4. The reduced-pressure coating apparatus according to claim 1, further comprising a coating circulation means using a cyclone.