JP3355064B2 - Resin powder coating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for coating a welding seam of a can body with a molten film of a resin powder in order to mainly prevent corrosion. The present invention relates to an apparatus for satisfactorily applying resin powder to a welding seam portion of a can body while preventing contamination.

[0002]

2. Description of the Related Art An inner surface and an outer surface of a can body of a three-piece can used as a container for food or drink are subjected to a surface treatment for corrosion prevention and a surface treatment for decoration. In this type of surface treatment, painting, offset printing, laminating, and the like are collectively performed while leaving the end of the flat can-making material. Then, this can-making material is roll-formed into a cylindrical shape, and after joining both side edges of the can-forming material by means such as resistance mash seam welding, a film mainly for corrosion prevention is formed on the welded joint. Is formed.

[0003] The film is generally composed of a cured film obtained by applying a thermosetting resin solution, followed by drying and baking, or a molten film of a resin powder. An example of an apparatus for applying a resin powder to a welding seam portion of a can body in order to form a molten film of the resin powder is described in JP-B-62-47595. This will be briefly described with reference to FIG.

[0004] The resin powder coating apparatus comprises: a jetting means 3 for jetting resin powder from a welding means 1 toward a welding seam portion of a can body 2 running continuously; The can body 2 is disposed so as to be substantially opposite to each other across the traveling can body 2 and connected to the reduced-pressure suction source, and is traveling.
A semi-cylindrical resin powder collecting means 4 longer than the interval between the two,
A heating means for heating and melting the resin powder applied to the welding seam portion of the can body;

[0005] According to the resin powder coating apparatus, the resin powder ejected between the running can bodies is collected by the resin powder collecting means 4 and attached to a portion not heated by the heating means 5. As a result, contamination of the can body 2 with the resin powder is prevented.

[0006]

However, an air flow parallel to the running direction of the can body 2 is formed on the peripheral surface of the can body 2 described above due to the viscosity of the air. Therefore, the resin powder that is ejected by the ejection means 3 and floats near the inner surface of the can body 2 and the resin powder that is about to fly into the gap between the can bodies 2 is moved by the air flow. Body 2
Together with the resin powder collecting means 4 and moved to a place outside the collecting range of the resin powder collecting means 4 and scattered, thereby causing contamination of the can body 2 and the like.

As a method for solving this problem, it is conceivable to increase the collecting ability of the resin powder collecting means 4, for example, the suction force by the resin powder collecting means 4. However, this affects the floating state of the resin powder spouted from the gap between the traveling can bodies to the welded seam portion of the can body 2, and the resin powder cannot be applied uniformly and to a predetermined thickness. Inconveniences such as occur.

That is, in the above-described conventional resin powder coating apparatus, the resin powder scattered outside the welding seam portion of the can body can be maintained while maintaining the good application state of the resin powder to the welding seam portion of the can body. And it was difficult to prevent contamination of the can body and the like.

The present invention has been made in view of the above circumstances, and it is possible to satisfactorily apply resin powder to a welding seam portion of a can body while preventing contamination of the can body and the like by resin powder. It is an object of the present invention to provide a resin powder coating device.

[0010]

Means for Solving the Problems To achieve the above object, an invention according to claim 1 is an apparatus for applying a resin powder to a welding seam portion of a can body, comprising: ,
It has a lead portion for resin powder provided to face a welding seam portion of a continuously running can body, and charges the resin powder ejected to this lead portion to charge the weld seam portion of the can body. Coating means for electrostatically applying a resin powder to a can body having a suction port disposed substantially opposite to the lead-out portion with a welding seam portion of the can body therebetween, and running continuously. A first suction means for sucking the resin powder leaked into the gap between the first and second suction means, and a suction port arranged closer to a forward side of the can body in the running direction than the suction port; And a second suction means having a suction force larger than the suction force of the first suction means.

The invention according to claim 2 is an apparatus for applying a resin powder to a welding seam portion of a can body, wherein the resin powder is applied to a welding seam portion of a continuously running can body. Coating means having a lead-out portion of resin powder provided to face each other, and charging the resin powder spouted to this lead-out portion to electrostatically apply the resin powder to a welding seam portion of the can body And a suction port disposed so as to be substantially opposed to the lead-out portion with the welding seam portion of the can body interposed therebetween, and sucks the resin powder leaked into a gap between the can bodies running continuously. A first suction means, and a suction port disposed inside the suction port and offset toward the front side in the running direction of the can body, and having a suction force larger than a suction force of the first suction means. And another suction means having a force.

[0012]

According to the first aspect of the present invention, the resin powder is supplied from the lead-out portion of the resin powder toward the welding seam portion of the can body, and electrostatic coating is performed. In that case, the resin powder that is about to leak to the outer surface side of the can body from the gap between the can bodies running continuously by the first suction means having a suction port disposed so as to be substantially opposed to the outlet portion. By suction, on the other hand, due to the airflow formed near the peripheral surface of the traveling can body, the resin powder that is about to leak to the forward side in the traveling direction of the can body,
The second suction means having a suction port disposed adjacent to the suction port of the first suction means on the front side in the running direction of the can body, outside the portion where electrostatic coating is performed. Through the gap between the continuously running can bodies, suction is performed from the front side in the running direction of the can body along the welding seam portion of the can body with a suction force larger than the suction force of the first suction means. .

[0013] In other words, the resin powder that is about to leak to the front side in the running direction of the can body is moved by the second suction means.
Suction is performed with a strong suction force that does not scatter in the circumferential direction of the traveling can body. For this reason, this resin powder does not adhere to portions other than the welding seam portion of the can body. Therefore, contamination of the can body and the like is prevented.

Since the suction operation by the second suction means is performed outside the portion where the resin powder is electrostatically applied, even if the suction force is increased, the suction operation of the resin powder can be performed. The influence on the floating state of the resin powder at the outlet is small,
Electrostatic application of the resin powder to the welding seam portion of the can body is not hindered, and the resin powder is applied uniformly and to a predetermined thickness.

According to the second aspect of the present invention, the resin powder is supplied from the resin powder outlet to the welding seam portion of the can body, and electrostatic coating is performed. In that case,
The resin powder that is to leak from the gap between the can bodies that run continuously to the outer surface side of the can body is sucked by the first suction means having a suction port disposed so as to be substantially opposed to the outlet section, On the other hand, due to the air flow formed near the peripheral surface of the traveling can body, the resin powder that is about to leak to the forward side in the traveling direction of the can body is separated by the first suction means and the first suction means. Another suction having a suction port locally disposed inside the suction port of the means and offset toward the front side in the running direction of the can body and having a suction force larger than the suction force of the first suction means. By means, the resin powder is sucked so as to be pulled back to the portion where the electrostatic coating of the resin powder is performed, and is sucked through the gap between the continuously running can bodies.

That is, the resin powder does not leak from the portion where the resin powder is electrostatically applied,
It is sucked by the first and second suction means. That is,
Since the resin powder does not scatter from the portion where the resin powder is electrostatically applied, the can body and the like are not contaminated.

Since the suction operation by the other suction means is performed only on a portion on the forward side of the portion where the electrostatic application of the resin powder is performed, the suction operation of the resin powder at the outlet of the resin powder is performed. The influence on the floating state of the powder, that is, the atmosphere of the lead-out portion is small, and the electrostatic application of the resin powder to the welding seam portion of the can body is not hindered.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the embodiments shown in FIGS. In FIG. 4, the resin powder coating apparatus of this embodiment mainly provides a welding seam in a cylindrical can body 10 and its vicinity (hereinafter referred to as a welding seam portion 10a) mainly for corrosion prevention. The resin powder 11 (hereinafter referred to as powder) made of an epoxy resin, a nylon resin, a polyester resin, or the like is applied.

This resin powder coating apparatus includes a welding means 12 for resistance mash seam welding of both side edges of a can forming material formed into a cylindrical shape and stacked, and a can body obtained by the welding means 12. Conveying means 1 for continuously conveying 10
3, 13 and at least the welded seam portion 10a of the can body 10.
, A coating means 15 for electrostatically applying powder 11 to a welding seam portion 10 a on the inner surface side of the can body 10 cooled by the cooling means 14, and a welding seam of the conveyed can body 10. Suction means 16 disposed so as to be substantially opposed to the application means 15 with the portion 10a interposed therebetween, and the suction means 16 of the can body 10 so as to form a molten film of the powder 11 applied to the welding seam portion 10a on the inner surface side of the can body 10. Welding seam 10a
And heating means 17 for heating.

Hereinafter, each means will be specifically described. The welding means 12 includes a pair of electrode rollers 18a and 18b arranged so that the circumferential surfaces thereof are opposed to each other. Both side edges on which a plate-shaped can material cut into a predetermined size is roll-formed and stacked. Parts are disposed opposite the electrode rollers 18a, 18b.
Mash seam welding by passing through the can body 1
It is configured to obtain 0. Injection nozzles of an inert gas (for example, N ₂ gas) not shown are appropriately provided toward the electrode rollers 18a and 18b, and welding by the welding means 12 is performed in an inert gas atmosphere. I have. Therefore, the welding seam portion 10a of the can body 10
Is prevented from being oxidized, and a molten film of the powder 11 is favorably formed.

The transporting means 13, 13 is for transporting the can body 10 obtained by the welding means 12 with its welded seam portion 10a positioned above, and includes a drive roller member connected to a drive shaft (not shown). Belt members 20, 20 made of a suitable rubber material and hung over the driven roller members 19 b, 19 b held rotatably, are in contact with both sides of the can body 10 drawn out from the welding means 12. It is arranged. Then, the can body 10 derived from the welding means 12 is moved at a predetermined interval to about 100 m / min.
The driving roller members 19a, 19a are configured to be driven so as to continuously convey at (1.7 m / s).

The cooling means 14 is disposed between the welding means 12 and the coating means 15 and cools air cooled to a predetermined temperature supplied from an air supply source (not shown) through a chiller to a can body. 10, a predetermined range from above, that is, the can body 10
Are sprayed at a predetermined flow rate to the welding seam portion 10a.

The temperature of the welding seam portion 10a of the can body 10 cooled by the cooling means 14 is set to a temperature (for example, about 55 ° C.) lower than the softening temperature of the powder 11 (about 60 ° C.). An increase in the heat load of the means 14 and the subsequently arranged heating means 17 is avoided.

The coating means 15 is for applying the powder 11 to the welding seam portion 10a of the can body 10 so that a coating film of the powder 11 is formed to a thickness of about 50 μm. As shown in FIGS. 4 and 5, the powder nozzle body 21a disposed on the inner surface side of the can body 10 to be conveyed comes into contact with the outer surface of the can body 10 passing through the coating means 15, and one end thereof is grounded. Ground brush 22
(In FIG. 5, for convenience, the position is shifted from diagonally below to diagonally above and shown.)

The powder nozzle body 21a is provided with a powder nozzle portion 21b which is opened to face the welding seam portion 10a of the can body 10 to be conveyed, and a plurality of electrodes connected to a static electricity generator (multiplier). The pins 23 are buried in a line in the transport direction of the can body 10 so that the tip ends face the powder nozzle portion 21b.

Further, a pair of masking members 25 are opposed to the powder nozzle body 21a in the conveying direction of the can body 10 so as to be in sliding contact with the inner surface of the can body 10 to be conveyed, and the height thereof can be adjusted. Attached to. The masking members 25, 25 are made of a brush member made of glass fiber having excellent heat resistance and abrasion resistance, or a sheet member made of fluororesin in which glass fiber is woven.

The can body 10 of the powder nozzle 21b is
On the rear side (so-called upstream side) in the transport direction of
A powder supply path 26 is connected to a powder storage unit (not shown) that stores the powder 11 having no lump due to moisture or the like, and the powder 11 is supplied to the powder nozzle 21b in a suspended state. It is configured as follows.

On the other hand, the powder nozzle portion 21b has a forward (so-called downstream) portion in the transport direction of the can body 10,
A powder recovery path 27 communicating with the powder supply source is connected to recover the powder 11 that has not been applied to the welding seam portion 10a of the can body 10. further,
The powder nozzle body 2 is attached to the powder nozzle body 21b so as to cover the downstream portion of the powder nozzle portion 21b from above.
A cover member 21c is provided extending from the downstream side portion (rear end portion) of 1b toward the upstream side. The upper surface of the cover member 21c faces the welding seam portion 10a on the inner surface side of the traveling can body 10 at a predetermined interval, and the lower surface thereof is gradually inclined toward the powder recovery path 27. The movement of the powder 11 to the powder recovery path 27 is performed smoothly, and the second and third powders described later are used.
The movement of the powder 11 to be collected into the powder collection path 27 is not hindered by the suction operation of the suction means of (1).

As shown in FIGS. 1 to 3, the suction means 16 includes a first suction means 16a, a second suction means 16b, and a third suction means 16c. The first suction means 16a has a suction port arranged so as to be substantially opposed to the powder nozzle portion 21a of the application means 15 with the welding seam portion 10a of the can body 10 being conveyed therebetween. And the first
The second suction means 16 is provided outside the suction port of the suction means 16a.
b, and a third suction means 16c is provided inside the suction port of the first suction means 16a.

More specifically, the second suction means 16b has a suction port outside the suction port of the first suction means 16a and the suction port of the first suction means 16a.
Are arranged adjacent to each other on the front side in the transport direction. Further, the third suction means 16c is arranged such that its suction port is biased toward the inside of the suction port of the first suction means 16a and to the front side in the running direction of the can body 10. In this case, the suction port of the third suction means 16c is connected to the cover member 21c.
The powder nozzle 21b is disposed downstream from the tip of the powder nozzle 21b.
It is preferable to reduce the influence on the floating state of the powder 11 formed on the substrate. Therefore, the third suction means 1
6 corresponds to another suction means in claim 2.

The suction means 16a, 16b,
16c is connected to a suction source such as a suction port of a blower (not shown). The suction means 16
a, 16b, and 16c are provided with pressing roll members 28, 28 that come into contact with the upper surface of the can body 10 being conveyed.
The suction ports 6a, 16b, and 16c are arranged so as not to obstruct the suction ports. In addition, a roll member 29 that comes into contact with the lower surface of the can body 10 to be conveyed is provided. Therefore,
The transport of the can body 10 by the transport means 13, 13 is performed smoothly, and the upper surface of the transported can body 10 and the suction means 16a,
The space between the suction ports 16b and 16c is appropriately maintained.

The flow rate of air near the upper surface of the can body 10 conveyed by the first suction means 16a (hereinafter referred to as suction speed) leaks into the gap between the can bodies 10 conveyed continuously. The suction speed by the second suction means 16b is set to an extent that the powder 11 can be sucked, for example, 0.8 to 1.7 m / s, and the conveying speed of the can body 10 (about 1.7 m / s). Greater speed, for example 4.2 m /
s, and the suction speed by the third suction means 16c is such that the powder 11 to be translated together with the conveyed can body 10 can be sucked, for example, 2.4 m / s.
s.

The heating means 17 is disposed downstream of the coating means 15, that is, on the front side in the transport direction of the can body 10.
The powder 11 applied to the No. 0 welding seam portion 10a is melted to form a molten film. The heating means 17 is provided in a predetermined range where the powder 11 is applied,
That is, the high frequency induction heating device is capable of appropriately heating the welded seam portion 10a of the can body 10 partitioned by the masking members 25, 25.

The operation of the resin powder coating apparatus configured as described above will be described. The can body 10 obtained by the welding means 12 is conveyed to the cooling means 14 by the conveying means 13 and 13, and the welding seam portion 10a is cooled to a predetermined temperature. On the other hand, in the powder nozzle portion 21b facing the welded seam portion 10a on the inner surface side of the cooled can body 10, an electric field toward the weld seam portion 10a of the can body 10 is formed by the electrode pin 23, and the powder 11 is suspended. Derived in turbid state.

The powder 11 led to the powder nozzle 21b is charged by the electrode pins 23, and the can body 10 is grounded via the ground brush 22. Therefore, the charged powder 11 is supplied to the masking member 25,
It flies toward the welded seam portion 10a on the inner surface side of the can body 10 defined by 25, and adheres to the welded seam portion 10a of the can body 10 by Coulomb force. That is, can body 1
The electrostatic application of the powder 11 is performed on the welding seam portion 10a of No. 0.

Since the welding seam portion 10a of the can body 10 on which the powder 11 is electrostatically applied is cooled to a temperature at which the powder 11 does not melt, the applied powder 11 is not melted, and Welding of the powder 11 derived in a turbid state does not occur. Therefore, the powder 11 is not deposited locally on the welded seam portion 10a of the can body 10, and the coating film of the powder 11 is formed uniformly.

Further, since the masking members 25, 25 are only in sliding contact with the can body 10 cooled to a predetermined temperature, the temperature of the masking members 25, 25 does not rise to the softening / melting temperature of the powder 11. Therefore, the powder 11 does not weld to the masking members 25, 25, and the masking members 25, 25 are prevented from being deformed, that is, deteriorated with time.

By the way, of the powder 11 led to the powder nozzle portion 21b in a suspended state, the powder 11 flies into the gap between the can bodies 10 that are continuously conveyed, and from this gap to the outer surface side of the can body 10. The powder 11 to be leaked is the first
This powder 1 is sucked by the suction means 16a.
1 does not adhere to the outer surface of the can body 10 or the like.
Is not contaminated.

Then, due to the air flow formed near the inner surface of the can body 10 being conveyed, the powder nozzle portion 21b serving as the outlet of the powder 11 and the suction port of the first suction means 16a are opposed to each other. The powder 11, which tends to leak from the portion where the powder 11 is electrostatically applied to the welding seam portion 10 a of the body 10 to the front side in the transport direction of the can body 10 along with the transport of the can body 10, travels The suction is performed by the second suction means 16b and the third suction means 16c through the gaps between the can bodies 10 to prevent the contamination of the can body 10 and the like by the powder 11 to be leaked.

More specifically, the second suction means 16b is provided outside the portion where the electrostatic coating is performed, and particularly, from the front side in the transport direction of the can body 10, the second suction means 16b attempts to leak. The powder 11 to be sucked is sucked at a suction force larger than the suction force of the first suction means 16a, specifically, at a speed higher than the transport speed of the can body 10. Therefore, the powder 11 does not scatter in the circumferential direction of the can body 10, thereby effectively preventing contamination of the can body 10 and the like. In addition, the second suction means 16
Since the suction port of b is disposed outside the portion where the powder 11 is electrostatically applied, the powder nozzle 21b
Atmosphere of the powder 11 formed on the substrate, that is, the powder 1
1 does not adversely affect the suspended state. Therefore, the electrostatic application of the powder 10 to the welding seam portion 10a of the can body 10 is favorably performed.

Further, the third suction means 16 c is
The powder 11 in a floating state, which tends to leak to the front side in the transport direction, is sucked so as to be pulled back to the portion of the powder 11 where the electrostatic coating is performed. That is, the powder 11 floating in the narrow space between the welding seam portion 10a on the inner surface side of the can body 10 and the upper surface portion of the cover member 21c is separated through the gap between the can bodies 10 running continuously. Suction is performed with a suction force larger than the suction force of the first suction means 16a. Therefore, the powder 11 floating near the inner surface of the can body 10
Is partitioned by masking members 25, 25, etc.
The powder 11 does not leak from the portion where the electrostatic coating is performed to the front side. Therefore, contamination of the can body 10 and the like does not occur. Note that the third suction means 16c does not increase the suction capacity of the first suction means 16a in the entire area, and furthermore, a cover member 21c is provided so as to face the suction port of the third suction means 16c. So powder nozzle 2
The adverse effect on the atmosphere due to the powder 11 formed in 1b is small, and good electrostatic coating of the powder 11 is maintained.

Further, the powder 11 which is to fly out of the range defined by the masking members 25, 25, etc. from the gap between the continuously running can bodies 10 and to leak to the front side in the running direction of the can body 10 is provided. Even if there is, the first having a suction port surrounding the suction port of the third suction means 16c
Of the can body 10 and does not leak to the front side in the running direction of the can body 10.

In the resin powder coating apparatus described above, the first suction means 16a, the second suction means 16b, and the third suction means 16c are combined.
Suction means 16a and the second suction means 16b or the first
Of the suction means 16a and the third suction means 16c. Of course, each suction means 1
Means for adjusting the suction direction and the like, for example, rectifying plates can be provided in the suction ports of 6a, 16b and 16c.

[0044]

As described above, the apparatus for applying resin powder of the present invention has a structure in which the air formed outside or inside the suction port of the first suction means near the peripheral surface of the traveling can body. Due to the flow, the outlet of the resin powder and the suction port of the first suction means are opposed to each other, and from the portion where the resin powder is electrostatically applied to the welding seam portion of the can body, There is provided a second suction means capable of sucking the resin powder to be leaked to the front side in the running direction of the can body with running. Therefore, contamination of the can body and the like by the resin powder can be prevented, and the resin powder can be favorably applied to the welded seam portion of the can body.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a suction unit according to an embodiment of the present invention.

FIG. 2 is a side view of the suction unit shown in FIG.

FIG. 3 is an operation diagram schematically showing an example of a flow rate of air near an upper surface of a can body conveyed by a first suction unit, a second suction unit, and a third suction unit.

FIG. 4 is a perspective view schematically showing an example of an entire coating line provided with the resin powder coating device of the present invention.

FIG. 5 is a diagram schematically illustrating an example of a coating unit according to the embodiment of the present invention.

FIG. 6 is a schematic view showing an example of a conventional resin powder coating device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Can body 10a Weld seam part of can body 11 Powder (resin powder) 15 Coating means 16 Suction means 16a First suction means 16b Second suction means 16c Third suction means 21b Powder nozzle part (lead-out of resin powder) Part)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-107974 (JP, A) JP-A-59-177164 (JP, A) JP-A-62-286572 (JP, A) JP-A 55-177 165162 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B05B 5/00-5/16 B05B 15/04 B05D 7/22 B21D 51/26

Claims (2)

(57) [Claims] An apparatus for applying resin powder to a welding seam portion of a can body, wherein the resin powder is applied to a welding seam portion of a continuously running can body. An application unit that has a lead-out part, and charges the resin powder ejected to the lead-out part to electrostatically apply the resin powder to a welding seam portion of the can body; and a welding seam portion of the can body. A first suction unit having a suction port disposed so as to be substantially opposed to the outlet section and suctioning resin powder leaked into a gap between the can bodies running continuously; and the suction port. A second suction means having a suction port arranged closer to the front side in the running direction of the can body than the first suction means, and having a suction force larger than the suction force of the first suction means. A resin powder coating device. 2. A resin powder application device for applying resin powder to a welding seam portion of a can body, comprising a resin powder coating device provided to face a welding seam portion of a continuously running can body. An application unit that has a lead-out part, and charges the resin powder ejected to the lead-out part to electrostatically apply the resin powder to a welding seam portion of the can body; and a welding seam portion of the can body. A first suction unit having a suction port disposed so as to be substantially opposed to the outlet section and suctioning resin powder leaked into a gap between the can bodies running continuously; and the suction port. And a suction unit having a suction port disposed to be offset toward the front side in the traveling direction of the can body, and having a suction force larger than the suction force of the first suction unit. A resin powder coating device.