JPS6223564Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is based on coatings on the outside of the can body of seamless can bodies, which are widely used as cans for beverage cans these days. This invention relates to a coating arrangement for the outer surface of a can body of a seamless can body, which has a can body with an inclined surface facing toward the center of the can body.

FIG. 1 is a side sectional view showing a typical shape of such a seamless can body, in which 1 is a straight body, 2 is the above-mentioned inclined surface, and 3 is a dome-shaped can that continues from the inclined surface and is convex inward of the can body. It is the bottom.

Appropriate coatings are applied to this seamless can body, and the exterior coating includes coating on the can bottom 3 and coating on the can body (body 1 and inclined surface 2). The former is usually applied by spraying, and the latter by using an application roll. Therefore, can bodies can be coated using two coating rolls, one for the body and one for the inclined surface, or by using one coating roll with an external shape that matches the external shape of the can body. This may be done with a coating roll. The present invention relates to an apparatus using a single application roll.

FIG. 2 shows an example of a coating station where coating is performed using a single coating roll. Reference numeral 10 denotes a coating roll consisting of a metal roll core 14 and an outer layer 15 made of an elastic material.
1, and an annular conical portion 12 which is in contact with the inclined surface 2 of the can body A. That is, roll 10
has an outer shape that matches the outer shape of the can body A, so the roll and the can body can rotate in contact with each other,
The barrel and inclined surfaces of the can will be painted at the same time. 20 is a first gold roll that contacts and supplies the coating material to the coating roll 10, and 30 represents a second gold roll that supplies the coating material to the first gold roll 20 in contact with it. As can be seen from the figure, the first gold roll 20 has a cylindrical portion 21 in contact with the annular cylindrical portion 11 of the applicator roll, and an annular conical portion 12.
and an inverted conical part 22 that is in contact with the coating roll, and the two are in rotational contact to supply paint to the entire outer surface of the coating roll. Further, the second gold roll 30 has a cylindrical part 31 and a conical part 31 that are in contact with the cylindrical part 21 and the inverted conical part 22 of the first gold roll, respectively, so that the paint can be supplied to the entire outer surface of the first gold roll. ing.

In such an apparatus, paint is first supplied to the outer surface of a second rotating gold roll, which is then transferred to the entire outer surface of a first gold roll that is also rotating;
Furthermore, it is transferred to the entire outer surface of the coating roll which is also rotating, and finally transferred to the entire outer surface of the rotating can body.

However, it has been found that there are serious problems with the transfer of paint using the paint station constructed in this manner. That is, defects occur due to non-uniform circumferential speed.

As mentioned above, the paint moves from the second gold roll to the first gold roll to the applicator roll to the can body, but in the meantime,
Simple cylindrical parts 31 and 21, 21 and 11, 1
There is no problem in transferring between 1 and 1), and uniform supply is possible, but transfer between the conical part and the inverted conical part (3
When transferring between 2 and 22, 22 and 12, and 12 and 2), since the outer peripheral speeds of the conical part and the inverted conical part are different, the paint moves more toward the side with the larger roll diameter. It shows a tendency and makes uniform supply difficult. However, this problem is most noticeable between the two gold rolls (32
and 22), between the coating roll with the elastic outer layer, the first gold roll and the can body,
Although this is not a practical problem, the fluidity of the paint decreases between the two gold rolls, resulting in uneven distribution and accumulation, and in extreme cases, even scorching.

The inventors of the present invention first attempted to avoid this phenomenon by adjusting the viscosity of the paint and adjusting the rotational speed of the rolls, but they could not obtain the desired results. It has been found that the desired purpose can be easily achieved by making the roll 40 a cylindrical roll that contacts only the cylindrical portion 21 of the first gold roll and does not contact the inverted conical portion 22 of the first gold roll. It is.

The only difference between FIG. 3 and FIG. 2 is the shape of the second gold roll. The outer layer of the coating roll is not particularly limited, but in this example, it has a swelling rate of 40% or less with respect to paint and solvent, and is A.
Butyl rubber was selected from those with a hardness of 30° to 50° using a rubber hardness meter.

The paint supplied to the second gold roll 40 is transferred to the cylindrical portion 21 of the first gold roll 20 by the rotation of the roll itself.
The paint is then transferred to the outer surface of the roll 2.
Due to the rotation of the coating material itself and the fluidity of the coating material itself, the coating material gradually spreads to the inverted conical section 22 and is transferred onto the outer surfaces of the cylindrical section 11 and the conical section 12 of the application roll 10. Note that 50 is a doctor blade for scraping off excess paint. Before starting the painting work on the can body, run it dry for a while and once the paint has sufficiently transferred to the coating roll as described above, bring the can body A into rotational contact with the roll 10 and it will be uniformly coated on the outside surface of the can body. A seamless can body with a beautiful coating is obtained.

In addition, when operating at extremely high speed, the outer layer 15
In order to prevent deformation, a large-diameter annular disc part 13 of an appropriate thickness may be formed on the applicator roll 10 following the conical part 12, as shown in FIG. It is also conceivable to form a small-diameter disk portion 23 following the inverted conical portion 22 to support the disk portion 13 of the applicator roll, but this is not an essential configuration for the present invention.

As described above, the present invention is an apparatus for painting the outer surface of a seamless can body, which is composed of a straight body part and the above-mentioned inclined surface following the straight body part. For a device consisting of an applicator roll having a cylindrical part and a conical part corresponding to the external shape of the applicator roll, and first and second metal rolls that supply paint to the applicator roll, the first metal roll has a cylindrical shape that matches the external shape of the applicator roll. The second gold roll is a cylindrical roll that contacts only the cylindrical part of the first gold roll, although the second gold roll has a cylindrical part and an inverted conical part. In other words, it enables uniform transfer of paint by avoiding uneven distribution of paint and occurrence of tightness, and since it has a simple structure, it can be said to be an extremely effective device in terms of quality control and practicality. be.

[Brief explanation of drawings]

Figure 1 is a side sectional view of an example of a seamless can body.
FIG. 2 is a schematic side view of an example of a device consisting of one coating roll and a first and second gold roll (only the coating roll is shown in cross section), and FIGS. 3 and 4 show the device of the present invention. FIG. 2 is a schematic side view of an example (only the applicator roll is shown in cross section). A... Seamless can body, 1... Straight body, 2... Inclined surface, 10... Application roll, 15...
...outer layer, 11... annular cylindrical part, 12... annular conical part, 20... first gold roll, 21... cylindrical part, 2
2... Inverted conical part, 40... Second gold roll.

Claims (1)

[Scope of Claim for Utility Model Registration] An apparatus for painting the outer surface of a seamless can body, which has a straight body part and an inclined surface extending toward the center of the can body at the end of the bottom side of the can body, which has an outer layer made of an elastic material. a coating roll, the outer layer of which includes an annular cylindrical portion that contacts the straight body of the can body and an annular conical portion that subsequently contacts the inclined surface of the can body; a coating roll that contacts and supplies paint to the coating roll; A device comprising a first gold roll that contacts and supplies paint to the first gold roll, wherein the first gold roll has a cylindrical portion that contacts an annular cylindrical portion and an annular conical portion of the coating roll, respectively. and an inverted conical portion, the second gold roll being a cylindrical roll that contacts only the cylindrical portion of the first gold roll.