JPS6174742A - Compensation method for joined part inner face of welded can - Google Patents

Abstract

PURPOSE:To improve a compensation quality by heating the welded part of the can body which is transferred continuously, then by affixing, re-heating, etc. with a roller press a tape shaped resin film. CONSTITUTION:The can body blank 2 seam-welded by a welder 4 is transferred by a transfer belt 3 and heated to more than the melting temp. of a film 6 by pre-heating device 5. The resin film 6 being wound on a bobbin is led to the upper face of an inner part press roller 10 via the recessed groove 1a of a guide arm 1. The film 6 is then delivered automatically with the progress of a can body and welded with heat to the inner face of the can body joined part, also placed into close contact with by press rollers 10, 14. After the film 6 being cut by the differential speed of belts 7, 20 the affixing strength is elevated due to the secondary heating further. With said method a defective compensation of the inner face of the joined part is eliminated and the compensation quality is elevated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for applying a tape-shaped resin film to the inner surface of a joint part of a welded can and correcting the coverage of the part.

[Background of the invention]

Solder cans, adhesive cans, and the like are used as can bodies with side joints, but in recent years, welded cans have also come into practical use. Welded cans are usually made of tin-plated steel or nickel-plated steel.

Using tin-free steel, blank plates, etc.
A method of creating a can body blank that is painted and printed, excluding the edges to be welded, rolling it into a cylindrical shape, overlapping the blank edges, and performing electrical resistance seam welding to form the can body. Therefore, the welding step at the can body weld joint is relatively large, and the cut end face of the can body blank remains with exposed metal as a welding step, and the unpainted surface of the metal material is exposed around the outside. Therefore, it is essential to correct the coating of the can body weld joint and its vicinity.

[Conventional technology]

As a method for correcting the coating of the can body weld joint and its vicinity as described above, a method of performing correction painting using various paints has been generally practiced. However, with coating correction using general-purpose solvent-based paints, it is not possible to cover the welded step part with an appropriate film thickness, and with coating correction using powder coatings, etc., thick coating can be achieved, but workability deteriorates. There is a problem.

As a method for solving the problems of such correction painting methods, various methods of attaching a resin film to the welded seam have been studied. However, such resin films are generally
Weld seam steps and exposed metal surfaces in the vicinity, as well as
Due to poor adhesion to the outer protective coating layer and poor melt fluidity, the resin film cannot enter the welded seam step without any gaps, and the heating temperature is increased to improve melt fluidity. However, there is a problem in that the surface treatment of the can material and the grease-resistant film itself deteriorate and change due to heat, resulting in insufficient coverage of the relevant parts.

In addition, resin films are generally prone to static electricity, and metal powder floating in the air or generated near welding parts,
Other fine particles tend to adhere to the welded joint, and if the welded joint is molten and pressed in such a state, the part will have poor adhesion and become a correction defective part. If there is such a defective correction area, if the contents are filled and temporarily stored, corrosion will occur in the area, the resin film will peel off, the quality of the contents will deteriorate due to metal elution, and even holes may appear. causing the problem of leakage of contents.

[Purpose of the invention]

The present invention was developed in view of the above circumstances, and it solves the problems of the conventional technology using a simple and rational method, and completely corrects the inner surface of the weld joint using a tape-shaped resin film. It is an object of the present invention to provide a correction method that does not cause corrosion, metal elution, or leakage of contents due to the occurrence of defective correction portions.

[Means to solve the problem]

The method of correcting the inner surface of welded can joints according to the present invention solves the problems of the prior art. During the conveyance, pre-heating the seam weld joints in order from the preceding can body to a temperature equal to or higher than the melting temperature of the tape-shaped resin film; A process in which a tape-shaped resin film that is automatically fed out by the conveying action of the can body is adhered by a pair of upper and lower pressure rollers placed inside and outside the can body to perform primary correction of the joint, and seam welding. Department,
A step of performing secondary correction by reheating at a temperature lower than the heating temperature in the pre-heating step, and a step of automatically cutting the tape-shaped resin film between the front and rear can bodies and separating the can bodies individually. It is characterized by:

[Explanation of Examples]

Embodiments of the method of the present invention will be described with reference to the drawings.

Figure 1 is a partially cutaway front view of the apparatus for carrying out the method of the present invention, Figure 1 is an enlarged view of the apparatus up to the film sticking apparatus in Figure 1, Figure J is an enlarged view of the apparatus for applying the film sticking apparatus. figure,
Figure 1I is a sectional view of the guide arm of the tape-shaped resin film, and Figure 3 is a front view of the pressure roll portion for applying the film.

It is supported horizontally and is connected via a circular guide arm (insulated joint at the welding part of a seam welding machine) (/b) as shown in the cross-sectional diagram.
) A cylindrical can body blank (2
) is fed along the guide arm (1) to the right from the >1 fixation with the joint facing up, and the can body blank (2
) is seam welded by a seam welder (4), and is fed downward at a constant speed by a conveyor belt (3) provided along the lower surface of the guide arm (1). On the way, this weld joint is further heated to a temperature higher than the melting temperature of the tape-shaped resin film (6) by a pre-heating device (5) provided on the lower side, and the heated can body is heated to a temperature higher than the melting temperature of the tape-shaped resin film (6). The speed V of the belt (3) is transferred onto the slower conveyor belt (force) and the can bodies are brought closer to each other.

On the other hand, the tape-shaped resin film (6) wound around the bobbin passes through the guide wool (8) and passes through the guide arm (
1) A concave groove (
lα), and through the guide roll (9) which is pivotally supported on the extended lower side of the guide arm (1), the can,!
It is guided to the upper surface of the internal pressure roller a2 located inside the cylinder. This internal pressure roller α0 has its upper end pivoted on the guide arm (1), and a spring αD is elastically installed between the lower end and the guide arm (1), so that the lower end is upwardly biased. It is rotatably supported by a shaft on the pressing lever α2.

0 in the figure. ll is a support roller that is pivotally supported by the guide arm (1) at the front and rear of the pressing lever Q2 and comes into contact with the surface of the conveyor belt (7), and there is a space between the support roller α3 and the surface of the conveyor belt (7). This allows the can body to intervene.

Then, the tip of the can body that has been preheated first is brought into pressure contact with the internal pressing roller aω, and the external pressing roller α with which this is pressed.
When intervening during the bleeding, the tip of the tape-shaped resin film (6) that has been guided in advance is thermally welded to the inner surface of the weld joint of the can body, and as the can body advances, this tape-shaped resin film (6) 6) is automatically fed out, and the tape-shaped resin film (6) is sequentially attached to the weld joint of the can body, and a pair of upper and lower inner and outer pressing rollers (10)
, 1,1 due to the pressing force of σ(a)? As shown in figure S, they are tightly attached without any gaps. By the way, since the above-mentioned inner and outer pressing rollers α0) and αzu are made of a heat-resistant elastic material such as rubber, synthetic rubber, or synthetic resin, the tape-shaped resin film (6) does not conform to the shape of the weld joint. It is then pasted on.

In this way, the tape-shaped resin film (6) is continuously attached to the weld joint of the can body following the first can body. The weld joint of the first can body is then reheated in a post-heating device α9 which is provided on the lower side and whose heating temperature is lower than that of the pre-heating device, preferably lower than the melting temperature of the resin film. It is heated to further increase the adhesion strength of the tape-shaped resin film (6) to the weld joint. Then, a pair of upper and lower inner and outer pressing rollers α61 are provided on the downstream side of the heating device α9. (17) may be used to press again. The configuration and support structure of the inner and outer pressure rollers αe and αD are similar to those of the first inner and outer pressure rollers (lG) described above.

The mechanism is similar to that of α leakage. α Old support roller O
The corrected can body that has been reheated and preferably repressed is conveyed by the speed-increasing roller (21) at the right end in FIG. The speed υ of 2G and the circumferential speed V of the speed increasing roller 9 are the same speed, and the speed of this conveyor belt (20) and the circumferential speed of the speed increasing roller α are the same as the speed υ of the conveyor belt (force speed υ2 Therefore, the conveyance speed υ of the can body that is conveyed while being sandwiched between the speed increasing roller (19) and the conveyor belt, and the conveyance speed υ of the can body that is conveyed between the conveyor belt (19) and the conveyor belt (19) Due to the speed difference with the speed υ, the tape-shaped resin film bridged between both can doors is automatically cut and the can bodies are separated and transported to the next processing step.

Although electric resistance seam welding has been described as a welding means in the present invention, it is not limited to the embodiments because it is also possible to use means such as laser welding. The tape-shaped resin film used in the present invention is polyamide-based or polyester-based.

Known resin materials such as polyethylene and polyvinyl chloride can be used, but polyamide and polyester are preferred. Also, the film shape is width j ~/
j fi, thickness 00! r~0! ;u is preferred.

〔effect〕

As described above, according to the present invention, the following effects can be obtained.

(α) It goes without saying that the weld joint can be corrected by pasting a tape-shaped resin film on the preheated weld joint and further pressing it with a pressure roller. By reheating, the correction can be further strengthened and the problems of the prior art can be completely solved.

(b) Since the reheating temperature is lower than the preheating temperature, preferably lower than the melting temperature of the resin film, the primary correction will not be destroyed by the reheating process and stronger fixing can be achieved. .

(c) Since the tape-shaped resin film is fed out along the guide arm so that it can be isolated from the welding part of the seam welding machine and the pre-heating process, there is no change or deterioration of the resin film due to heating from that part. There is no adhesion of metal powder or other fine particles due to the welding arc, and there is no correction failure due to poor adhesion, and the problems of the prior art can be eliminated.

Since the speed υ of the conveyor belt that carries out the process of reheating from adhering Cd) 2/ is made smaller, the speed υ of the conveyor belt that conveys the corrected can body is made smaller, so that the speed of the conveyor belt that conveys the can body after correction is smaller. The tape-shaped resin film in a bridge state between the can bodies is automatically cut by the difference in conveying speed, and the can bodies are easily separated into individual can bodies. There is no need to provide a mechanism.

(Li) Pressure bonding is performed using a pair of upper and lower inner and outer pressure rollers on the lower side of the post-heating device, so the Japanese language film is pressure-bonded twice.In addition, the temperature of the post-heating is kept relatively low, and the resin film is The welding joint can be properly welded without causing any damage.

[Brief explanation of drawings]

The figures show an example of an apparatus for carrying out the method of the present invention, and Fig. 1 is a partially cutaway front view, Figs. Cross-sectional view of the arm part,
Figure 5 is a front view showing the pressed state of a portion of the inner and outer pressing rollers. (1)...Guide arm 1 (/α)...Concave groove,
(2)... Can body blank, (3), (7), H
... Conveyor belt, (4) ... Seam welding machine, (5)
... preheating device, (6) ... tape-shaped resin film. (8), (9)...Guidance page, (10)...
Internal pressure roller, αυ...Spring, αδ...Press lever, αy...Support roller, Side...External pressure roller, 09...Post-heating device, αe...Internal pressure roller, (17 )...External pressure roller, 0 mark...
Support roller, (13... speed-increasing roller. Fig. 4 Fig. 5 (j6)

Claims (1)

[Claims] (1) (a) A large number of welded cans are continuously conveyed in tandem so that they are seam welded and the seam welds are aligned on the same line. Preheating the seam weld joints in order from the can body to a temperature higher than the melting temperature of the tape-shaped resin film; (b) transporting the can body to the seam weld joints on the heated inner surface of the can body; A tape-shaped resin film that is automatically unrolled by action,
(c) reheating the seam weld at a temperature lower than the heating temperature in the preheating process; (d) Next, automatically cutting the tape-shaped resin film between the front and rear can bodies to separate the can bodies individually. Internal correction method. (2) A method for correcting the inner surface of a welded can joint according to claim 1, in which the seam weld joint faces upward. (3) A method for correcting the inner surface of a welded can joint according to claim 1, wherein a tape-shaped resin film that is fed out from a welded part of a seam welding machine and a preheating process is separated by a guide arm. (4) The can body conveyance speed υ_2 until the completion of the tape-shaped resin film attachment process and the reheating process is slightly slower than the can body conveyance speed υ_1 up to preheating, and the interval between can bodies during film attachment is shortened. A method for correcting an inner surface of a welded can joint according to claim 1. (5) The relationship between the can transport speed υ_3 after the completion of correction due to reheating and the can body transport speed υ_2 until the completion of reheating is υ
The method for correcting the inner surface of a welded can joint according to claim 1, wherein _3>υ_2 is set, the interval between can bodies is forcibly expanded, and the connected tape-shaped resin film is automatically cut. (6) The method for correcting the inner surface of a welded can joint according to claim 1, wherein a re-pressing step using a pair of pressure rollers is provided on the downstream side of the re-heating step.