JPH047269B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application The present invention relates to a method of coating a portion of a substrate to be coated.

Prior Art Methods for painting the end of a base material such as a decorative board, a floor board, a ceiling board, an actual finished or decorated end, or a part of the surface of the base material include, for example, roll coating,
Alternatively, various methods are known, such as applicator coating using a ring or the like, spray coating, and shower coater coating.

Problems with the Prior Art In applicator coating, an applicator roll or applicator ring is brought into contact with the surface of the substrate to be coated, and the paint is transferred and applied via the roll or ring. Therefore, if the painted surface has irregular irregularities, a roll or ring with auxiliary irregularities is used. When applying applicator coating to thin substrates or substrates that have undergone actual processing, the end of the wood may be damaged by contact with rolls, rings, etc. Therefore, it is necessary to adjust the contact pressure. difficult.

In spray painting, paint loss is large, and the nozzle is easily clogged due to dust and paint scum in the paint, and the nozzle must be maintained and inspected frequently, resulting in poor efficiency and high cost.

Shower coater painting is a method in which paint is discharged from a discharge port and a portion of the surface of the substrate is coated while the substrate is moved close to the discharge port, but it is difficult to make the amount of coating uniform. Furthermore, it is difficult to strictly limit the application area on a portion of one surface of the base material.

Means for Solving the Problems In the present invention, paint is supplied into a painting box having a painting opening on the side wall for painting a part of the base material beyond the level of the painting opening, while the paint is supplied inside the painting box. The pressure is reduced by a depressurizing means to suck air from the coating port, thereby preventing the paint from spilling out, and the base material is brought into pressure contact with the coating port outside the coating box and moved. Air suction is prevented in at least a part of the opening surface of the mouth, and the paint is guided to the part to apply the coating to the part of the base material exposed to the coating mouth.

By varying the size and shape of the coating spout, it is possible to ensure that the coating spout is sealed when the substrate is pressed into the coating spout, or to form a gap in selected areas around the opening surface of the spout. It is also possible to cause 〓 to occur.

If the substrate seals the coating spout, this prevents air suction and the paint flows toward the coating spout and coats the portion of the substrate exposed in the coating spout.

When the base material covers a portion of the coating opening, a gap is created between the substrate and the coating opening at a selected periphery of the coating opening, and air is drawn from the gap between the coating opening and the coating opening. The air flow may also remove and dry excess paint applied to the substrate.

For example, if the substrate covers the lower part of the coating spout and there is a gap in the upper part, air will be drawn from the upper part of the coating spout, thereby directing the paint to the part of the substrate exposed to the coating spout. Then, the coating is applied to the surface of the base material exposed to the coating opening.

Furthermore, by retracting the side wall of the downstream portion of the coating port in the direction of movement of the substrate, the substrate is guided along the upstream side wall of the coating port, and when the substrate covers the coating port, the coating is completed. A gap is created between the downstream edge of the mouth periphery and the base material. During this time, the air sucked in from the bottom flows horizontally for a certain distance toward the upstream side, and eventually becomes bubbles and rises. In the area of the coating port that is not covered by the air flow, the air flow guides the paint to coat the portion of the substrate exposed in that area.

By providing appropriate auxiliary means at the coating opening,
It is also possible to coat the wood end of a base material having irregularities provided in an arbitrary shape.

Effects According to the present invention, even if paint is supplied beyond the level of the coating port of the coating box, overflow of the paint can be prevented by sucking air from the coating port due to the reduced pressure inside the coating box. .

By moving the base material in pressure contact with the coating opening on the outside of the coating box, air suction is prevented in at least a portion of the opening surface of the coating opening, and the paint is guided to the area exposed to the coating opening. Painting can be applied to the base material.

By varying the size and shape of the coating spout, it is possible to ensure that the coating spout is sealed when the substrate is pressed into the coating spout, or to form a gap in selected areas around the opening surface of the spout. It is also possible to cause 〓 to occur.

If the substrate seals the coating spout, this prevents air suction and allows the paint to flow toward the coating spout and coat the portion of the substrate exposed in the coating spout.

When the base material covers a portion of the coating opening, a gap is created between the substrate and the coating opening at a selected periphery of the coating opening, and air is drawn from the gap between the coating opening and the coating opening. The air flow may also remove and dry excess paint applied to the substrate.

For example, if the substrate covers the lower part of the coating spout and there is a gap in the upper part, air will be drawn from the upper part of the coating spout, thereby directing the paint to the part of the substrate exposed to the coating spout. The coating can be applied to the surface of the base material exposed to the coating port.

Furthermore, by retreating the side wall of the coating box in the downstream part of the coating port in the direction of movement of the base material,
The substrate is guided along the upstream side wall of the coating port,
When the base material covers the coating opening, a gap is created between the downstream edge of the peripheral area of the coating opening and the substrate, and air sucked from this gap is directed toward the upstream side by a certain distance. The paint flows horizontally and eventually rises as bubbles, but in areas where the airflow does not reach, the paint is guided by the airflow and is able to coat the parts of the substrate exposed in those areas. can.

By providing appropriate auxiliary means at the coating opening,
It is also possible to paint the wood end portion of the base material which has irregularities provided in an arbitrary shape.

Furthermore, by providing an air suction port on the downstream side of the coating port in the direction of movement of the substrate, excess applied at the coating port can be removed by the high-speed airflow at the suction port, thereby drying the painted surface.

The coated substrate can be immediately dried to touch-dryness by a high-speed suction air stream from the coating port and/or the air suction port.

The amount of coating can be adjusted by adjusting the viscosity of the paint, adjusting the negative pressure inside the coating box, adjusting the conveyance speed of the substrate, adjusting the distance between the substrate and the coating port, etc. The most desirable method is to keep the viscosity of the paint and the decompression capacity of the depressurizing means constant, provide a secondary air intake to adjust the negative pressure inside the paint box, and use high-speed air at the painting port and/or air suction port. It is best to adjust the speed of the flow and the amount of paint blown off. This method allows fine adjustment of the coating amount.

Furthermore, by providing auxiliary means at the coating port,
It is also possible to change the coating mode.

DESCRIPTION OF THE EMBODIMENTS FIG. 1 is a schematic side view of an apparatus for carrying out the method of the invention. The paint box 10 has a paint port 11 on the side surface for applying paint to the base material. The top surface of the coating box can be opened for cleaning, maintenance, and inspection of the interior, and it is desirable that the lid 12 be able to seal it. Further, it is desirable that a guide plate 13 for guiding the substrate be provided at the level of the lower edge of the coating port 11.

The paint supply means 20 is shown as a paint tank 21, a pipe 22 leading from the tank to the paint box, and a pump 23 provided in the pipe. Paint supply means 2
The paints supplied by 0 are not particularly limited, and include commonly used synthetic resin paints such as epoxy resins, vinyl resins, polyurethane resins, unsaturated polyester resins, acrylic resins, and chlorinated rubber resins. can be used. Among these, particularly water-based paints such as water-soluble paints and water-dispersible paints, and solvent-free paints such as UV-curable paints are preferably used. A solvent-based paint may be used, but a large amount of the solvent evaporates while the paint circulates between the paint box 10 and the paint tank 21 and is constantly sucked by the vacuum pump 32, so the solvent must be replenished. This is disadvantageous in terms of cost.

The pressure reducing means 30 is shown as a pipe 31 opening at the top of the coating box and a vacuum pump 32 sucking air from the pipe.

The paint is supplied above the level of the coating port 11,
On the other hand, by reducing the pressure inside the coating box by the pressure reducing means 30, air from the outside world is sucked from the coating port 11, thereby preventing paint from overflowing from the coating port. In other words, a vacuum is applied within the coating box to the extent that air is sucked in at a sufficient speed to prevent paint from overflowing from the coating port. In order to provide the required reduced pressure atmosphere inside the coating box 10, when the size of the coating port 11 is 20 to 100 mm in length x 180 to 300 mm in width,
For example, set the suction force by the vacuum pump 32 to 300 to 2000.
Must be mmAq. This suction force is not limited to the above range as it varies depending on the opening size of the coating port 11, the size of the substrate to be coated, and the type and amount of paint to be applied to the substrate. , which can be arbitrarily set and adjusted.

The base material is placed on the guide plate 13 and the coating port 1
It is moved so that it is pressed against 1. When the base material is pressed against the coating port 11, if the coating port is completely sealed by the base material part, air is not sucked and the paint is applied to the part of the base material exposed to the coating port. be done. In this case, the paint applied to the base material is scraped off at the periphery of the coating port 11, and at the downstream edge in the moving direction of the base material.
The paint film becomes extremely thin and a sealing coat is applied. In this case, an auxiliary air suction port (not shown) is provided on the side of the coating box on the downstream side of the coating port 11 with respect to the direction of movement of the substrate to provide air flow to the coating surface and dry the coating material. It's good. It is necessary to take care that air suction from this auxiliary air suction port is not obstructed by the base material. When painting only the inner surface of the grooves of a base material that has one or more grooves extending in the direction of movement on one flat surface,
All you have to do is press the surface against the coating port and move it. When a base material with grooves covers the coating opening, air is sucked in from both ends of the groove, but the middle part of the groove exposed to the coating opening is painted in the same manner as described above, and the groove The surfaces on both sides and/or the peaks between the grooves are also painted. However, the paint adhering to the surface of the peak is scraped off by the downstream edge of the coating port.
The amount of paint adhering to the inner surface of the groove is blown off in proportion to the speed of the air flow, but it is not completely blown off, and the remaining paint is dried by the air flow. Further, the secondary air suction means 40 is connected to the coating box 10.
It can be installed on top of the paint box to prevent excessive negative pressure from occurring inside the paint box. The secondary air suction means is shown as having a pipe 41 and a valve 42, which can also be used to adjust the amount of excess paint scraped off by adjusting the valve 42.

If the height of the coating port 11 is made larger than the height of the base material, the coating port 11 will not be sealed by the base material, and air will flow from the top surface of the base material to the upper part of the coating port 11. is sucked into the paint box through the
The sucked air rises in the paint as bubbles and escapes into the air above the paint box. Due to this movement of air, the paint is guided to the surface of the base material pressed against the coating port 11, and coating is performed.

If the downstream peripheral part of the coating port 11 is set back from the other peripheral parts, the coating port will not be completely sealed even if the end of the base material is brought into pressure contact with the coating port 11, and the downstream peripheral part will not be completely sealed. Air continues to be sucked in. The sucked air is blown into the paint a limited distance toward the upstream side, and eventually rises as bubbles as described above. Coating port 11 in the direction of movement of the base material
By increasing the dimensions of the substrate, parts of the substrate can be coated in the area upstream of the coating port. Moreover, the airflow in the region downstream of the coating port 11 serves to remove excess paint and dry it to a touch-touch level. In this case, by setting it back inside the wall surface of the painting box on the downstream side of the painting port 11, it is possible to avoid the painted surface of the base material coming into contact with the wall surface of the painting box and causing damage. If necessary, a guide means for guiding the movement of the base material can be provided.

In FIG. 1, paint extraction means 50 is also shown in the paint box 10, which is used to remove the paint from the paint opening 11 when the pressure inside the paint box increases for some reason.
Drain the paint into the paint tank before it spills out. In FIG. 1, the paint removal means 5
0 is shown as consisting of piping 51 and valve 52. The valve 52 is normally closed, and can be an automatic valve that opens automatically when the pressure inside the paint box exceeds a predetermined pressure, and can be linked to a pressure detection means inside the paint box. Such pressure sensing means as well as automatic valves themselves are known and therefore will not be described in detail. The paint removing means may be provided with a pump, if necessary.

The paint inside the paint box is violently agitated by the air sucked in from the paint port 11 and/or the secondary air suction means 40, which prevents the pigments in the paint from settling and also prevents the separation of paint components. do.

When the sucked air forms bubbles and escapes above the paint box, the paint image is carried away into the air as droplets along with the bubbles. In FIG. 1, a gas-liquid separation means 60 is shown connected to the pressure reduction means 30. The paint separated by the gas-liquid separation means is collected in the paint tank 21. Such gas-liquid separation means itself may be of a known type. The gas-liquid separation means 60 can also be provided within the coating box. For example, a plurality of baffle plates 61 are provided above the paint box, air containing droplets is blown toward the surface of the paint, and the droplets are shaken off to the surface by gravity and/or centrifugal force. Also good. In order to prevent paint from adhering to the baffle plate or to remove the adhered paint, a solvent may be sprayed onto the baffle plate.

The pressure reduction means is provided in the paint tank 20 instead of in the paint box 10, and the upper part of the paint box and the upper part of the paint tank are communicated with each other through a communication means (not shown), thereby indirectly reducing the pressure inside the paint box. You may do so.

The coating port 11 shown in FIG. 1 is formed on one plane, and therefore there is a limit to the shape of the substrate that can be coated with it. It is desirable to use the same equipment for coating the ends of substrates of different thicknesses, for coating different widths on one surface of a substrate, and for coating uneven surfaces of substrates. To change the size and shape of the coating port 11, an easily replaceable adapter can be used. To be more specific, the size and shape of the coating port 11 are set to the maximum expected size and shape,
Adapters having coating ports 11 of different sizes and shapes are removably attached by suitable fixing means such as bolts and nuts. Several embodiments of such adapters are shown schematically in FIG. In these figures, the coating box 10 has a U-shaped groove 14, as shown in FIG.
A U-shaped coating opening 11 is provided along the inner surface of the groove, and the adapter 15 is shown as having a generally U-shaped cross-sectional shape that fits within the groove. However, the groove 14 in the paint box
It is easily understood that it is not essential to provide.

FIG. 2b is a partial sectional view of the area of the coating port 11 of the coating box 10 taken along a vertical plane, showing an embodiment of the adapter 15 suitable for coating the end of a base material having a rectangular cross section. . The adapter 15 installed in the groove 14 has a U-shaped cross section, its outer surface matches the inner surface of the groove 14 of the coating box 10, and the adapter 15 has a U-shaped cross section at a position corresponding to the coating port 11. A U-shaped opening 16 is provided across the bottom wall of the adapter and a portion of each opposing side wall. As a result, the U-shaped opening of the coating port 11 is substantially limited by the opening of the adapter 15. adapter 1
The bottom wall of 5 is aligned with the plane of the edge 17 of the aperture 16 in the side wall of the adapter on the upstream side of the aperture 16 and is set back in the plane indicated by 18 on the downstream side of the aperture 16. I'm forced to. Although not shown in the drawings, the adapter 15 is fixed to the paint box by suitable fastening means. In order to make the drawings clear, there is shown as if there is a slight gap between the cross-sectional outer shape of the base material S and the cross-sectional inner shape of the adapter 15, but in reality there is almost no gap. Base material S
is guided along the bottom wall on the upstream side of the opening 16 (a plane passing through the periphery of the opening indicated by 17 in the figure). When the base material does not cover the opening 16, external air is sucked in the direction perpendicular to the opening surface (from the right side to the left side in the figure) due to the reduced pressure inside the coating box 10. When the substrate approaches the opening 16, the edge of the substrate partially covers the opening 16, and assuming that the negative pressure inside the paint box remains unchanged, the speed of the airflow that is drawn in increases, but , the flow direction of the airflow hardly changes. In the areas covered by the substrate in the openings 16, the air flow guides the paint so that it begins to coat the portions of the substrate exposed to the openings 16. When the substrate covers the aperture 16, due to the above-mentioned characteristics of the bottom wall of the adapter, a small gap is left only around the downstream side of the aperture 16, and due to the reduced pressure inside the paint box, outside air can be sucked out between the two. is sucked in at high speed. At this time, the air flow sucked into the paint flows horizontally toward the upstream side, but eventually turns into bubbles and rises, escaping into the air above the paint box. If there is an area upstream of the opening 16 that this airflow does not reach, the paint in that area is dragged by the airflow and guided to the surface of the base material exposed to the opening 16, and painting is performed. That will be understood. On the other hand, the air flow sucked from the above-mentioned gap
Blow off excess paint and allow the painted surface to dry. On the downstream side of the opening 16, the above-mentioned features of the bottom wall of the adapter allow the painted surface of the substrate to be moved without contacting the bottom wall of the adapter, so that the painted surface is not damaged. If necessary, make sure that the painted surface of the base material does not come into contact with the bottom wall of the adapter.
Means for guiding the substrate may also be provided.

FIG. 2c is also a cross-sectional view similar to FIG. 2b, in which the upper corner of the cross section of the base material S is curved and decorated at the end of the base material and a part of the upper surface of the base material. An adapter 15 for painting is shown. In this embodiment, the upper corner of the cross section of the adapter 15 is deformed into a shape similar to the cross-sectional shape of the end of the base material, and the opening 16 is formed in most of the side wall of the adapter located above. It is similar to the azaptor of FIG. 2b, except that it extends. The coating opening 11 is limited by an opening 16 of the adapter 15, and the portion of the substrate exposed to the opening 16 is coated. On the downstream side of the opening 16, the portion of the inner wall of the adapter corresponding to the opening 16 is set back, thereby removing excess paint from the painted surface S1 of the base material and drying the painted surface in the same manner as described above. It will be done.

FIG. 2d is also a similar cross-sectional view, showing an adapter 15 suitable for reinforcing coating of the real part of the base material S having male seeds. In this embodiment, the cross-sectional shape of the bottom wall of the adapter 15 is deformed to a shape similar to the cross-sectional shape of the base material, and the opening 16 is formed on the bottom wall of the adapter 15.
The adapter is similar to the adapter of FIG. 2b, except that it is formed over a modified bottom wall and a portion of a pair of side walls.

FIG. 2e is also a similar cross-sectional view and shows an adapter 15 suitable for reinforcing coating of the fruit part of a base material S having female seeds. This embodiment is also similar to the embodiment of FIG. 2b, except for the same features as FIG. 2d, and will therefore not be described in detail.

FIG. 2f is a similar sectional view showing an adapter 15 suitable for painting the end of a substrate having a rectangular cross section and a portion of the front and back surfaces adjacent to the end. This embodiment is substantially the same as the embodiment of FIG. 2b, the only difference being that the adapter opening 16 is formed over a wider portion of the pair of side walls. Therefore, no further explanation is necessary.

FIG. 3 is a cross-sectional view of the base material S and the auxiliary means 70 added to the coating port 11 or the opening 16 of the adapter 15. This auxiliary means 70 consists of a block 71 made of a suitable material, with ridges 72 on one surface thereof.
It has a paint scraping surface on which parallel protrusions are formed as shown by and troughs 73. Positioning the auxiliary means 70 by an appropriate fixing means so that the protrusion is oriented in the direction of movement of the base material and the paint scraping surface is brought into contact with the base material on the downstream side of the coating port 11;
Fix it. It will be understood without further explanation that this allows a draft-like coating to be applied to the surface of the substrate.

Although the present invention has been described above with reference to some embodiments, the present invention is not limited to the above-described embodiments, and various changes can be made without departing from the technical idea of the present invention.

For example, the direction of relative movement between the base material and the coating port during the coating process does not need to be linear.

The shape of the paint scraping means can be changed in various ways.
It will also be clear that various coating modes can thereby be obtained.

The pressure reduction means need not be directly connected to the paint box. For example, by connecting a depressurizing means to the paint tank and providing communication means to allow air to circulate between the upper part of the paint box and the upper part of the paint tank, the pressure inside the paint box can be indirectly reduced. good.

By moving the substrate so as to provide different distances between the coating opening and the substrate, it is also possible to partially apply different coating thicknesses to the painted surface.

In the above description, the uneven shape on the surface of the base material is the unevenness of the cross-sectional outline of the base material, and does not change when painting a base material that has irregularities in the moving direction of the base material, such as a beaded edge. However, it will be understood without explanation that the method of the present invention can also be applied to coating a substrate having such an uneven shape.

It is also possible to use two coating apparatuses to coat opposing surface portions of the substrate at the same time or at different times.

From the above description, it will be understood that by the method of the present invention, partial coating of a substrate can be performed easily, economically, and efficiently.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of an apparatus for carrying out the method of the present invention, and FIG. 2 is a diagram showing a modification of the apparatus and some embodiments of adapters used therewith. Figure 2a is a perspective view of a modified example, Figure 2b
~f is a cross-sectional view showing the relationship between the peripheral portion of the U-shaped groove of the device and various adapters and base materials, and FIG. 3 is a cross-sectional view showing an example of an auxiliary means for changing the coating mode. It is a diagram. Explanation of symbols, 10: Paint box, 11: Paint opening, 1
2: Lid body, 13: Guide plate, 14: U-shaped groove,
15: Adapter, 16: Adapter opening, 17:
Edge, 18: Surface, 20: Paint supply means, 21: Paint tank, 22: Piping, 23: Pump, 30: Pressure reducing means, 31: Piping, 32: Vacuum pump, 40:
Secondary air suction means, 41: Piping, 42: Valve, 5
0: Paint scraping means, 51: Piping, 52: Valve,
60: Gas-liquid separation means, 61: Baffle plate, 70: Auxiliary means, 71: Block, 72: Peak, 73: Valley.

Claims (1)

[Scope of Claims] 1. A paint box having a coating port on the side wall for applying paint to a portion of a base material, while supplying paint beyond the level of the coating port, while reducing the pressure inside the coating box. Paint is prevented from overflowing from the coating port by suctioning air from the coating port, and the part of the base material to be coated is brought into pressure contact with the coating port on the outside of the coating box and moved. 1. A method for partially painting a base material, comprising guiding a paint to at least a part of an opening surface of a mouth, thereby painting a part of the base material. 2. In the method described in claim 1,
When the base material is pressed into the coating port,
The size and shape are such that a slight gap is created between the base material and the periphery of the coating opening at the selected periphery of the opening of the coating opening, and air is sucked from between the base material and the periphery of the coating opening. A method for partially painting a base material, which is characterized by guiding the paint to a part of the material. 3. In the method described in claim 2,
A method for partially coating a substrate, characterized in that the gap is formed by making the height of the coating port larger than the height of the substrate. 4. In the method described in claim 2,
The above-mentioned gap is formed by retracting the downstream edge of the coating port inward from the other edges in the moving direction of the substrate when the substrate is pressed against the coating port. A method for partially painting a substrate, characterized in that excess paint applied on the upstream side of the spout is removed by an air stream flowing in at high speed from the downstream edge of the coating spout. 5. In the method described in claim 1,
A partial coating method for a substrate, characterized in that an air suction port is provided on the downstream side of the coating port in the moving direction of the substrate, and excess paint applied at the coating port is removed by a high-speed air flow at the suction port. .