JPH08299861A - Method and device for powder spray coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suck a powder coating material from a delivered container to supply it to a spraying device so that fine particles existing in the atmosphere do not invade and the powder coating material, particularly the fine particles, are not scattered from the delivered container to the surroundings not to dirty the coating space and the equipment therein. SOLUTION: In this powder spray coating method, the powder coating material is supplied from the delivered containers 12, 14 to the spraying device 30 by means of air pressure while putting a spray coater into operation by a fluidizing/sucking device 23 which is dipped into the delivered container through an outflow hole 70 of an upper container. The outflow hole 70 of the upper container is covered with a covering device 20 and the fine particles are sucked from the delivered container at the upper point of the powder level 36 through the covering device 20 by a sucking air current 33. The fine particles existing on the outside of the delivered container are sucked and filtrated using a sucking air current other than the current 33. The air required for the sucking air currents is sucked into the delivered container 12 from the open air through the covering device 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder spray coating method and apparatus described in the claims.

[0002]

2. Description of the Related Art German Laid-Open Patent Publication No. 4239496
From A1 there is known a powder spray coating device which is capable of delivering a powder coating to a spray device by means of a vaporization and suction device which can be immersed in the container from the delivery container. For details of the submersible fluidization / suction device, see German Published Patent Publication No. 401.
Known from 2190 A1. Delivered container He is usually a cardboard box or bag or other container that is opened upwards after being involved. The powder is extremely light and contains fine dust in addition to the fine powder particles necessary for spray painting. Dust may enter the delivery container opened from the surroundings. Another drawback is that when the fluidization / suction device is immersed in the delivery container and the powder is fluidized inside it, fine particles of powder and especially dust are scattered by the fluidization / suction device and scattered from the delivery container. There is. The powder must be fluidized in order to be able to suck.
Before the submersible vaporization and suction device was invented, the powder from the delivery container into a separate container with a closable lid and an air-permeable floor for the inflow of powder fluidizing air. I was replacing the paint. However, a delivery container in the form of a bag cannot have a lid. Furthermore, the size of the delivery container varies, and none have a lid that is secured to the delivery container during powder suction.

[0003]

SUMMARY OF THE INVENTION The object of the present invention is to prevent dust mixed with the atmosphere from entering, and to disperse powder, especially dust, from the delivery container to the surroundings, and to contaminate the coating space and the equipment therein. To aspirate powder from the delivery container. The above objective is accomplished by the independent claims of the present invention. Advantageous refinements of the invention are stated in the dependent claims. The present invention can be used not only for delivery containers, but also for all powder containers that are open at the top.

[0004]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The powder spray coating apparatus shown in FIG. 1 includes a cabin 1 in which a coating object 2 is coated with a powder coating material 4 by a spray apparatus 3. The coating object 2 is transported by the transport device 5 through the cabin 2.
The floor of the cabin is formed by a filter band 6 which circulates in the direction of the arrow 7, which carries the excess powder falling on the filter band 6 to the outside of the cabin 1. The first powder station 8 is equipped with a lifting device 9 and a vibrating table 10. A cardboard box 13 on the vibrating table 10 and a bag 14 projecting upward from the cardboard box 13 and containing powder paint.
A delivery container 12 composed of and is placed. The upper end of the bag 14 is opened by being inserted from the bottom to the top through a horizontally provided carrier ring 16 and being folded back outward through the carrier ring. The carrier ring 16 is the lifting device 8
The height can be adjusted. Carrying ring 16
Since the cover device 20 is seated on the upper side, the upper end portion 15 of the bag 14 folded back by the carrying ring 16 is sandwiched and fixed between the carrier device 20 and the carrying ring 16. The carrying arm of the height-adjustable lifting device 9 carries a fluidization / suction device 23, which is the cover device 20 shown in FIG.
In the basic position above, the powder can be dipped into the bag 14 through the cover device 20 for delivery to the spray device 3. The fluidizing / suction device 23 is connected to a compressed air source 26 and at least one air connecting pipe 2 for feeding.
3 and a metering air connection pipe 25. The compressed air source creates a negative pressure in the injector 27 of the fluidization / suction device 23, and this negative pressure sucks the powder coating material from the bag 14 and feeds it to the spray device 3 using air pressure. A part of the feeding air 24 or the metering air 25 is a fluidizing / suction device 2
3 from the lower end 28 flows into the powder coating in the bag 14, whereby the powder coating is fluidized and can be sucked in by the feed air. A more detailed explanation in this respect is given in German published patent application DE 4012190 A1 and German published DE patent 4239496 A1.

In order to prevent the powder and its feeding air from being scattered from the cabin 1 to the surrounding working chamber, air 33 is passed from the cabin 1 through the filter band 6 through the exhaust pipe 30 and the auxiliary filter 31 of the exhaust fan 32. Since it is sucked, a slight negative pressure is maintained in the cabin 1. The same exhaust fan 32 as described above is connected to the exhaust port 35 of the cover device 20 via the auxiliary filter 31 and the intake pipe 34, and sucks dust from the bag 14 to above the powder level 36. The air sucked from the bag 14 by the air fan 32 is accompanied by the outside air into the bag 14 through the single or plural outside air suction ports 37. With this outside air suction port 37, the exhaust fan 32
It is possible to avoid that the suction air flow of the above obstructs the fluidization / suction device 23 for powder feeding. Excess powder carried out from the cabin 1 by the filter band 6 is sucked by the suction fan 4
0 is sucked by the suction nozzle 41 into the powder separating device 43 through the powder suction pipe 42, and the surplus powder is separated from the suction airflow in this separating device, so that the suction airflow does not contain powder and dust and the suction fan. It can flow from 40 to the ambient atmosphere. If the powder separation device 43 is for multicolor work (change of various colors), the cyclone separator 4 is used.
4 and a filter separator 45 arranged on the downstream side thereof. The fine powder particles separated from the suction air flow by the filter separator 45 are returned to the bag 14 through the squeeze valve sluice 47, the downstream strainer 48 and the powder recovery pipe 49, and the powder suction port 50 of the cover device 20. , Recovered. For single color work (always the same type of paint), the filter separator 45 can be omitted and the cyclone separator 44 is directly connected to the suction fan 40.

The fluidizing / suction device 23 can uniformly deliver a fixed amount of powder coating material to the spray device 3 only when the powder level 36 in the bag 14 is kept constant. For this reason, again, the container 12 is of the same construction as the powder station 8 and has the cover device 20 mounted thereon, so that the bag 14 does not have to be emptied and the spray painting operation has to be interrupted. A second powder station 8.2 having a Therefore, the same reference numerals are attached to the same parts. Also from this cover device 20, the intake pipe 34 passes through the auxiliary filter 31 and the exhaust fan 3
Connected to 2. The only difference is that the powder inlet 50 of the cover device 20 is closed, since no powder is filled in this second powder station 8.2. However, in another embodiment, a structure may be possible in which the powder is also filled in the second delivery container 12 and therefore the powder suction port is opened. The fluidizing / suction device 23 of the second powder station 8.2 is the bag 14 of the container 12.
Through the powder feed pipe 51, the powder suction pipe 42, the cyclone separator 44, the squeeze valve sluice 47, the strainer 48 and the powder recovery pipe 49 through the powder inlet of the cover device 20 of the first powder station 8 there. Delivery container 12
The powder coating material is conveyed to the bag 14 of. The fluidization / suction device 2 for the powder in the delivery container 12 of the second powder station 8.2 without passing through the cyclone separator 44 and the strainer 48.
It could also be conveyed directly from 3 to the powder inlet 50 of the delivery container 12 of the first powder station 8. However, the fresh powder is uniformly mixed with the recovered powder by passing through the cyclone separator 44 and the strainer 48, and is sucked from the delivery container 12 of the first powder station 8 into the spray device 3. The advantage is that the impurities are removed before.

Within the delivery container 12, at least within the delivery container 12 of the first powder station 8, the powder level 36 is monitored and depending on the powder level 36 from the delivery container 12 of the second powder station 8.2. A level sensor is provided for adjusting the powder feed rate, whereby the powder level 3 in the delivery container 12 of the first powder station 8 is adjusted.
6 is always kept constant. The first powder station 8 will now be described on behalf of both powder stations 8 and 8.2. The cover device 20 is a funnel 60 which is tapered downwards.
And a lid 61 seated on this funnel.
The lower end of the funnel 60 has a cylindrical bushing 62 which passes through the carrier ring 16 and projects through the carrier ring 16 into the open end 15 of the bag 14. Since the diameter of the lower end of the funnel 60 and its bushing 62 is smaller than the shortest inner diameter of the bag 14 used as a delivery container, and the diameter of the carrying ring 16 is slightly larger than that, the upper end of any bag of any size. The part 15 can also pass between the carrier ring 16 and the bushing 62 and can be folded back on the carrier ring 16. If a bag 14 with a larger diameter is used, its upper end 15 can be folded between the carrying ring 16 and the bushing 62, so that the bag can be fitted with the funnel 20 and carrying ring 16 regardless of size. It can be sandwiched between and thereby fixed and closed.

In alternative embodiments, various sizes of carrier rings can be used that can be interchangeably secured to the lifting device 9. This allows it to accommodate bags of various diameters.
The carrying ring 16 and the bag upper part 15 folded back by this ring
It is not necessary to fit and into the funnel 60 at the shortest diameter portion of the funnel 60, and it is possible to fit at any portion where the funnel 60 has a larger diameter. The lid 61 hermetically seals the upper end of the funnel 20 except for the slit 37 between the lid 61 and the upper edge portion 38 of the funnel 60. The slit 37 covers the outside air 61
Forming an outside air suction port 37 that flows along the lower side of
At this time, the fine powder particles are blown into the bag 14 again from the lower side of the lid 61 and from the inside of the funnel, while the outside air is sucked from the funnel 20 through the exhaust port 35 by the exhaust fan 32. The air filter 6 is suitable for the outside air inlet 37.
2 is provided, and this filter prevents dust from the outside air from entering the bag 14. Figure 2 shows fluidization
A suction device 23 is shown, the solid line being the cover device 20.
The upper initial position is shown, the dotted line shows the state of being completely immersed in the bag 14, and the arrow 64 shows the dipping device.

A through-hole 70 is formed in the lid 61, the size and shape of which are adapted to the fluidizing / suctioning device 23. The fluidization / suction device 23 is hermetically enclosed in this through-hole 70, thereby preventing air from entering the bag 14 when it is immersed in the bag 14, and
On the other hand, when drawing out from the bag 14, the fluidizing / suction device 23
A packing ring 72 for removing the powder from the bag and collecting it in the bag 14 is provided. A compressed air ring 74 having a nozzle opening 75 and a peeling edge 76 inside the through hole 72 is provided on the lower side of the packing ring 72, and the peeling edge connects the fluidizing / suction device 23 from the bag 14 to the through hole 70. It plays a role of separating the powder from the outer peripheral surface of the fluidizing / suction device 23 when the powder is drawn upward through the through. The packing ring 72 and the compressed air ring 74 are exchangeably housed in the through hole 70 and are held by a snap-type closing device 78.
3 and 5 show the powder station 8 without the delivery container 12. Delivery containers are cardboard boxes, bags,
Alternatively, as in FIGS. 1 and 2, it may be a bag in a cardboard box. Other types of containers may be used. Here, the delivery container means a container of the powder coating material that the powder coating material manufacturer delivers to the user who sprays the coating material on the coating object. Such a delivery container is generally called a “container”.

FIG. 3 shows the fluidizing / suction device 23, and the dotted line shows the upper basic position, and the solid line shows the position lowered to the blowing device 80 of the vibrating table 10. This blowing device 80 is incorporated in the vibrating table 10 and blows the powder on the lower end side out of the powder line and the injector of the fluidizing / suction device 23 before the device is used for another powder. Blows compressed air into the fluidizing and aspirating device 23 to remove air from the device. During the operation of blowing the powder from the fluidizing / suction device 23 and the injector 27, the feeding air pipe or the metering air pipe 25 may be closed, or the blowing device 80 may be used from below. The supply air and the compressed air are fluidized against the pressure of the compressed air blown into the fluidization / suction device 23.
The supply air and the compressed air must be supplied with such strength that they can flow out at the lower end of the suction device 23. The powder paint in the container 12 is "fluidized" by the vibration of the vibrating table 10.
Therefore, it assists the fluidizing action of the fluidizing air flowing into the container 12 from the fluidizing / suction device. Vibrating table 1
If a stationary table is used instead of zero, a larger amount of fluidizing air is needed.

As shown in FIGS. 4, 5 and 6, the fluidizing / suction device 23 is provided with a plurality of injectors 27 instead of a single injector 27, and each injector 2 is provided with a plurality of injectors 27.
7 delivers the powder coating to another spray device 3. The plurality of injectors 27 are integrated as a unit, or block, which is shown in plan view with a rectangular cross section in FIGS. 4, 5 and 6 and in plan view with a circular cross section in FIG. However, other shapes may be used. The basic advantages of the invention will now be summarized. The powder stations 8 and 8.2 can be used for delivery containers of various sizes and their plastic bags 14. Instead of the exhaust fan 32, a commercially available dust suction device may be connected to the exhaust port 35 of the cover device 20. Powder station 8
And 8.2 can be used later in any commercially available spray device in place of the previously used user container. By using the cover device 20 having a function of automatically cleaning the fluidizing / suction device 23, time is required in the case of color exchange, that is, when one type of powder paint is changed to another type of paint. Significant savings and minimal work interruption.

Fluidizing / suction device 23 even during spray painting
Even during cleaning, no dust is generated that would cause adjacent equipment to become dirty. The closed intake system and dust discharge system do not contaminate the powder paint with powder or dust of a different color. According to the present invention, in order to clean the delivery containers 12 and 14 of the fluidizing / suction device 23 and the lower side of the cover device 20, a stronger suction airflow can be generated from the exhaust fan 32 than during the spray painting operation. , Whereby powder remnants are sucked from the part. At the same time, the feed air from the feed air pipe 24 and the metering air pipe 2
The metering air from 5 can be supplied or shut off at higher pressures in larger quantities.

[Brief description of drawings]

FIG. 1 is a schematic view of a powder spray coating apparatus according to the present invention.

FIG. 2 is a powder station according to the invention with a delivery container or a bag inside a cardboard box forming the container together.

FIG. 3 is the powder station of FIG. 2 without a delivery container.

FIG. 4 is a plan view of the powder station of FIG.

5 is a plan view of the powder station of FIG.

FIG. 6 is a plan view of the fluidizing / suction device of the powder station of FIGS. 2 to 6;

FIG. 7 is a plan view of an embodiment in which the dipable fluidizing / suction device has a circular cross section.

[Explanation of symbols]

 1 Cabin 2 Coating Object 3 Spraying Device 4 Powder Paint 5 Conveying Device 6 Filter Belt 7 Arrow 8 Powder Station 8.2 Powder Station 9 Elevating Device 10 Shaking Table 12 Delivery Container 13 Cardboard Box 14 Bags 15 Bag Ends 16 Carrying Ring 20 Carrying Device 22 Carrying arm 23 Fluidization / suction device 24 Air pipe for feeding 25 Air pipe for metering 26 Compressed air source 27 Injector 28 Lower end 30 Exhaust pipe 31 Auxiliary filter 32 Exhaust fan 33 Air 34 Intake port 35 Exhaust port 36 Powder level 37 Outside Air Suction Port (Slit) 38 Funnel Upper Edge 40 Exhaust Fan 41 Suction Nozzle 42 Powder Suction Tube 43 Powder Separation Device 44 Cyclone Separator 45 Filter Separator 46 Dust 47 Squeeze Valve Sluice 48 Strainer 49 Powder Recovery Pipe 50 Powder Suction port 60 Funnel 6 Bushing 64 arrow 70 through opening 72 through opening 74 the compressed air ring 75 the nozzle opening 76 peeling edge 78 snap closure device 80 balloon device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B05D 3/00 B05D 3/00 B

Claims (14)

[Claims] 1. Fluidization in which powder paint is immersed from the delivery container (12, 14) into the delivery container through the outflow hole (70) of the upper container during spray coating operation by using air pressure.
In the powder spray coating process of the type in which the suction device (23) feeds the spray device (30), the upper container outflow hole is covered by the cover device (20), and the dust is sucked by the suction airflow (33). Delivery container (12)
Through the cover device (20) to the powder height level (3
6) Being sucked above, dust is delivered container (20)
Being filtered out of the suction airflow (33) on the outside of the air, and the air required for the suction airflow (38) being sucked into the delivery container (12) from the outside air through the cover device (20),
The process characterized by. 2. Powder spray coating process according to claim 1, characterized in that the outside air is filtered while being sucked into the delivery container (12). 3. A container (12) for delivering a cover device (20).
Powder spray coating process according to claim 1 or 2, characterized in that it is held by a carrier device (9) separate from. 4. A bag (14) is used as a delivery container (12), the upper end (15) of the bag (14) being inserted upwards from the bottom through a carrying ring (16) and subsequently carrying ring. Folding outwards beyond (16) and simultaneously opening, and then cover device (20)
The powder spray coating process according to claim 1, characterized in that the carrier ring is covered. 5. The delivery container (1) while the powder paint is extracted from the delivery container and conveyed to the spray device (3).
2) The powder paint is delivered through the cover device (20) in an amount such that the level of powder in the container is kept substantially constant (1
The powder spray coating process according to claim 1, wherein the powder spray coating process is supplemented in 2). 6. The cleaning of the delivery container (12), the fluidizing / suction device (23) and the lower side of the cover device (20) produces a suction air flow stronger than that during the spray painting operation, and At the same time, compressed air which is stronger than during the spray painting operation is blown into the delivery container (12) through a fluidizing / suction device or the compressed air is shut off. The powder spray coating process according to the item 1. 7. The powder coating material (4) was immersed in the delivery container (12) through the upper container outlet hole in order to convey the powder coating material (4) from the delivery container (12) to the spray device (3) by using air pressure. A powder spray coating apparatus having a fluidizing / sucking apparatus (23) is provided with a cover device (20) for covering the upper container outlet hole, and the fluidizing / suction apparatus (2).
3) The cover device (20) is formed with a passage hole for immersing the delivery container (12) in the delivery container (12), and dust is supplied from the delivery container (12) to the powder level (36) by an external suction air supply source (32). The cover device (20) is formed with a suction air connecting pipe (35) for sucking the air upward, and an outer air suction port (37) for re-sucking the air consumed by the suction air source (32). ) Is formed, the powder spray coating device. 8. A powder spray coating apparatus according to claim 7, characterized in that the outer air inlet (37) has an air filter (52). 9. The powder spray coating device according to claim 7, wherein the cover device (20) has a powder suction port (50) for replenishing the delivery container (12) with powder paint. . 10. The powder spray coating apparatus according to claim 7, further comprising a carrying device (9) for carrying the cover device (20) separately from the delivery container (12). . 11. A carrier ring in which the delivery container (12) comprises or consists of a bag (14) containing a powder coating, the carrier device (9) being arranged horizontally. (16), the bag upper part inserted from the bottom through the ring is folded around the ring and simultaneously opened, and the cover device (20) is surrounded by the bag part (15). 11. Powder spray coating device according to claim 10, characterized in that it is mounted on a carrying ring (16) which is present. 12. Cover device (20) for a carrier device (9).
The powder spray coating apparatus according to claim 10 or 11, characterized in that the position can be adjusted in the vertical direction. 13. Powder that adheres to the outside of the vaporization and suction device (23) is automatically removed, and is removed when the vaporization and suction device (23) is raised through the passage hole (70). Device according to one of claims 7 to 12, characterized in that a device (72, 74) for cleaning the vaporization and suction device (23) for returning the powder to the delivery container (12) is provided at the site of the passage hole (70). The powder spray coating apparatus according to the item. 14. A blowing device (80) is provided, which is integrated with the table (10) carrying the delivery container (12) and is arranged below the vaporization and suction device (23), Compressed air can be blown into the lower end face of the vaporization and suction device by means of a blowing device (80) in order to clean the powder duct while the delivery container (12) is off the table. 13. The powder spray coating apparatus according to item 13.