JPH10151668A - Method and apparatus for repairing joint of can body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To repair a welded seam of a can by efficiently covering the same and the periphery thereof with a resin in almost uniform thickness. SOLUTION: In a method for repairing a joint of a can body having a resin protective layer formed to the inner surface thereof by lamination or coating by covering the joint of a can body and the strip like non-resin protective parts formed on both sides of the joint with a resin, the non-resin protective part of the can body and the resin protective layers on both sides of the non-resin protective part are heated and softened and a linear thermoplastic resin material 5 having a definite cross-sectional shape is heated over the total length thereof and, while this linear thermoplastic resin material 5 is gradually pressed flatly so as to cover the non-resin protective part and the end parts of the resin protective layers and a resin film is formed so as to cover the non-resin protective part containing the joint of the can body while air between the resin material and the surface of the can body is expelled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a can having a resin protective layer formed on the inner surface thereof by laminating, coating, or the like, and to a resin can covering the seam of the can body and its periphery, and a resin coating method and apparatus.

[0002]

2. Description of the Related Art As shown in FIG. 4, a can body (63) of a metal can (6).
Is performed by abutting or lapping both ends of a rectangular metal plate. The inner surface of the metal can, which contains contents that are susceptible to metal corrosion, is made of a metal material to prevent deterioration of the contents due to elution of the metal, corrosion of the can itself due to the contents, and leakage of the contents due to this. At the stage of the metal plate, a resin protective layer is formed by coating or laminating. However, when joining the can body by welding, in order to avoid the necessity of energization and damage to the resin protective layer due to heat, the area where the resin protective layer is not applied (about , Non-resin protection portions (62) are formed at both ends of the metal plate of the material so that the non-resin protection portions remain.

Therefore, as shown in FIG. 5, after the can body is formed, the non-resin protection portion including the welding seam is coated with a resin coating (8).
Repairs are being carried out. This method of repairing resin coating includes "spray coating" in which a coating agent is sprayed with a spray, "brush coating" in which a brush is applied, "film bonding" in which a belt-shaped film is thermocompressed with a pressure roller, and fine powder of synthetic resin. After electrostatically adsorbed on the parts requiring repair, heat-melt polymerization is applied to form a coating film. "Powder electrostatic coating", fine powder of synthetic resin is injected with hot air and melted before reaching the parts requiring repair. ,
"Powder spray coating" that forms a film with this molten resin,
There is "hot melt resin coating" in which a synthetic resin melted in a heating tank is coated while being extruded from a nozzle. The above coating repair method and the formed coating have the following problems as shown in FIGS. 3A to 3D.

FIG. 3A is a cross-sectional view of a repair part by “spray painting” and “brush painting”. “Spray coating” causes the working environment to deteriorate due to the scattering of the coating agent in areas other than the necessary parts. "Brush coating" requires a great deal of time and effort, and requires a solvent recovery treatment facility, so that initial costs and running costs are high. Both "spray coating" and "brush coating" basically consist of resin molecules dispersed in a solution.
In addition, since the resin film 8 to be formed cannot be made thick, pinholes 75 frequently occur after drying. Apart from the parts that need repair,
The scatter of the resin to the outside is inevitable, and the scattered matter (80) remains on the inner surface of the can body (63). Moreover, since the coating agent has a low viscosity, it is easy to flow and it is difficult to form a resin film (8) having a uniform thickness. For example, the resin coating (8) is interrupted or thinned by the edge (63) of the metal plate (60) and the edge (70) of the resin protective layer (7), and the repair effect is impaired. The solvent may remain inside the repaired part, which may adversely affect the contents.

FIG. 3B is a cross-sectional view of the repaired portion by “film bonding”. Since a step is generated between the end of the resin protective layer (7) and the surface of the metal plate (60) in accordance with the thickness of the resin protective layer (7), the film and the non-resin protective portion ( It is difficult to escape the air (hereinafter, referred to as outgassing) between the inner surface and the inner surface of the resin film (8). There is a high possibility that acicular spatters formed during welding will break through the film. Work management is difficult because the film is thin and shrinks or stretches due to heat.

FIG. 3C is a cross section of the repaired portion by “powder electrostatic coating” and “powder spray coating”. Neither electrostatic powder coating nor powder spray coating can form a coating film having a uniform thickness. Further, since the particles are melted in a state where the particles are stacked, or the molten powder is sequentially stacked, countless bubbles (81)
And pinholes (75) are likely to occur. Inevitably, the powder is scattered to portions other than those requiring repair, leaving scattered matter (80).
Work management is difficult, and it takes time to set up during work and maintenance after work is completed. Both the powder electrostatic coating and the powder spray coating are very expensive in equipment. In addition, since the apparatus itself is large and ancillary facilities such as a powder recovery apparatus and a heating furnace are required, a large installation space is required.
Ancillary facilities are also expensive, and there is a problem that running costs increase.

FIG. 3D is a cross section of the repaired portion by “hot melt resin coating”. Hot-melt resin coating is unavoidable to introduce air bubbles, and pinholes (75) are likely to occur. The coating speed is slow, and it is difficult to control the adhesion state and the melting state of the resin. There is a problem that the set-up at the time of work and the maintenance after the end are troublesome, and the running cost is increased.

Furthermore, in any of the above-described methods for forming a resin film, there is hardly any resin suitable for being integrally melt-bonded to the resin protective layer (7), and the adhesive reliability with the resin protective layer (7) is low. Poor. Also, a dent (72) in the lap of the weld seam (61)
There was a problem that it was difficult to escape the air inside, and this remained as large bubbles.

[0009]

SUMMARY OF THE INVENTION The present invention is intended to improve the problems caused by each of the above-listed coating methods, that is, to improve the working environment, eliminate air bubbles and pinholes in the repair coating, and apply coating to portions other than those requiring repair. Provision of high-quality cans while preventing material scattering, forming high-precision repair coatings, shortening setup and maintenance time, speeding up repair work, eliminating costs and space savings by eliminating auxiliary equipment And a device that is easy to operate.

[0010]

The present invention comprises a laminate,
In a method for repairing a seam of a can body in which a resin protective layer (7) is formed on the inner surface by coating or the like and a band-shaped non-resin protection portion (62) formed on both sides of the seam with a resin, the seam of the can body is repaired. The non-resin protection part (62) of the body and the ends (71) and (71) of the resin protection layer (7) on both sides of the non-resin protection part (62) are heated and softened, and a linear shape having a constant cross-sectional shape over the entire length is obtained. The thermoplastic resin material (5) is heated and softened, and while being placed along the seam of the can body, the non-resin protection portion (62) and the end portion (71) of the resin protection layer (7) ( The linear thermoplastic resin material (5) is gradually squashed flat so as to cover the 71), and the air between the resin material and the surface of the can body is extruded while protecting the non-resin containing the seam of the can body. A resin coating (8) is formed to cover the portion (62).
A repair device according to the present invention includes a transport device (1) for transporting a can body in an axial direction thereof, and a can body transported by the transport device (1).
(63) are arranged in a row on the transition road and the seam (6
A plurality of pressure rollers (21) (22) (23) (24) capable of pressing 1),
Guide rollers (4) and (41) for supplying and guiding a linear thermoplastic resin material (5) to a pressure roller (21) through which a can body (63) first passes;
A heating device (3) for heating the vicinity of the seam of the can body sent to the thermoplastic resin material (5) and the pressure roller (21), and the plurality of pressure rollers (21), (22) and (23). (24) is a thermoplastic resin material in order from the pressure roller (21) that first presses the can
The pressing surface changes stepwise so that (5) can be crushed more flatly, and / or the thermoplastic resin material (5) is crushed more flatly in order from the pressing roller (21) that first presses the can. The pressing force is changing stepwise as much as possible.

[0011]

[Function and effect] The thermoplastic resin material (5) softened by heating is
The pressure rollers (21), (22), (23) and (24) press against the non-resin protection portion (62) of the can body (63). In the conventional "film bonding", in order to cover the non-resin protection portion (62) and press a band-shaped film having a width extending between the ends (71) and (71) of the resin protection layer (7),
There was no escape for air trapped in the air pocket generated by the step between the end portion (71) of the resin protective layer (7) and the non-resin protective portion (62) and the recess (72) formed by the wrap, and remained as bubbles. . On the other hand, in the present invention, the linear thermoplastic resin material (5) is heated and softened, and this is gradually pressurized by a plurality of pressure rollers, and gradually in the width direction of the non-resin protection portion (62). And cover the ends (71) and (71) of the resin protective layer (7). For this reason, the end portion (71) of the resin protective layer (7) and the non-resin protective portion (62)
Even if there is a step, and even if a dent (72) occurs due to the lap of the weld seam (61), the softened resin is not protected by the resin (62).
The width of the resin protective layer (7) is filled while excluding air from the end of the recess (72), and further overlaps by riding on the end (71) of the resin protective layer (7). No bubbles remain. When pressurizing the softened thermoplastic resin material (5), no air is entrained in the thermoplastic resin material (5), so that no air bubbles remain in the resin coating layer.

There is no problem that the coating is thinned or cut off at the edge of the resin protective layer (7) and the edge of the metal plate, which is difficult to avoid with the conventional repairable material having high fluidity. . The coating resin does not scatter and remain in unnecessary portions. Non-resin protection part (62) of can body (63)
Is pre-heated, so that it is familiar with the thermoplastic resin material (5) softened by heating, and because the thermoplastic resin material (5) is pressed against the non-resin protection portion (62) by a pressure roller, The bonding strength between the non-resin protection portion (62) and the thermoplastic resin material (5) is increased. The end portion (71) of the resin protective layer (7) is also softened by heating, and when the softened thermoplastic resin material (5) is put thereon and pressed, the resins are welded and integrated. Also, conventional repair materials often impair the inherent properties of the resin by being modified or made into a liquid or particulate form, but in the present invention, not only a synthetic resin modified as a repair material but also various known materials are used. Since it is possible to use a resin extruded product as it is, it is possible to select an optimum product in both adhesion and chemical resistance. The repair device includes a can body conveying device (1), a pressure roller row (2) for deforming the thermoplastic resin material (5) under pressure, a non-resin protection portion (62) of the can body (63), and a heat roller. It is a simple configuration consisting of a pressure roller row (2) for pressing the plastic resin material (5), and is less expensive than powder electrostatic coating or powder spray coating equipment. The thermoplastic resin material (5) is easier to handle and improves workability as compared with powder or film resin.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a resin-coated repairing apparatus. A transporting apparatus (1) for transporting a can body (63), and a can body (63) provided above the transporting apparatus (1). ) Non-resin protection part (62)
And a non-resin protection portion (62)
And a heating device (3) for heating a linear thermoplastic resin material (5)
And a linear thermoplastic resin material drawn from the drum (4)
Guide rollers (41) and (42) for guiding (5) to the pressure roller row (2)
It is constituted by and. In FIG. 1, the can body (63) moves from the left side to the right side, and the following repair work is performed. After the work is completed, the can body (63) moves from the right side to the left side and returns to the original position. In FIG. 1, the right direction is the downstream side, and the left direction is the upstream side.

The conveying device (1) is supported with a guide member (11) in which receiving rollers (12) and (12) are arranged at regular intervals in the conveying direction, and an opening directed toward the pressure roller row (2). It moves on the guide member (11) at a constant speed, and the rear end of the can body (63) is
A moving table (13) that moves the can body (63) in the reverse direction after passing through the roller (24) at the downstream end of (2) and returns it to its original position. The receiving rollers (12) (12) are forcibly rotated in the moving direction of the can body (63). In the embodiment, the pressure roller row (2) includes a first pressure roller (21), a second pressure roller (22), a third pressure roller (23), and a fourth pressure roller ( 24) -4
The two pressure rollers are arranged in a line at equal intervals. The arrangement pitch of the pressure roller is determined by the receiving roller (1) of the guide member (11).
2) The pitch is the same as that of (12), and each pressure roller is vertically opposed to the receiving roller (12) in pairs.

The pressure roller row (2) is rotatably mounted on a horizontally long support rod (20) via a bracket (25).
By turning the handle (26) connected to the bracket (25), the vertical position of the pressure roller can be finely adjusted.
The support rod (20) is connected to an elevating device (not shown) so that the guide member (11) can float on the pressure roller row (2) at a time. Each of the pressure rollers (21), (22), (23), and (24) is formed of silicon rubber, and has a concave groove (21a) in which the groove width and groove depth are sequentially changed as shown in FIG. I have. The peripheral groove (21a) of the first pressure roller (21) has a groove width slightly larger than a diameter of a linear thermoplastic resin material (5) described later, and a depth of the peripheral groove (21a) of the thermoplastic resin material (5). A round bottom groove slightly larger than the radius. The peripheral groove (22a) of the second pressure roller (22) has a groove width of about half the width of the non-resin protection portion (62) of the can body (63), and the first pressure roller (21) ) Is a round bottom groove shallower than the peripheral groove (21a). The circumferential groove (23a) of the third pressure roller (23) has a groove width approximately equal to the width of the non-resin protection portion (62) of the can body (63), and the groove depth is such that the central portion is slightly deeper. It is gently curved. 4th pressure roller
The circumferential groove (24a) of (24) is larger than the width of the non-resin protection portion (62) of the can body (63), and slightly lower than the roller end by the same height as a whole. The width centers of all the pressure rollers (21) to (24) are aligned on a straight line.

In the embodiment, the heating device (3) is provided with a first burner (3).
1), 2nd burner (32), 3rd burner (33), 4th burner (3
4), constituted by a fifth burner (35). Each burner is supported by a support rod (30), and the first burner (31) has its tip directed upstream. The second burner (32) is connected to the first pressure roller (2).
The front end of the pressure roller (21) is disposed downward at a position upstream of the pressure roller (21) close to (1). A third burner (33) is provided between the first pressure roller (21) and the second pressure roller (22), and is provided between the second pressure roller (22) and the third pressure roller (23). 4th burner (34)
However, a fifth burner (35) is disposed between the third pressure roller (23) and the fourth pressure roller (24) with the tip thereof facing downward. With respect to the support rod (30), the position of the first burner (31) can be adjusted in the front-rear direction, and the positions of the second burner (32) to the fifth burner (35) can be adjusted in the vertical direction. The drum (4) around which the linear thermoplastic resin material (5) is wound has a can body so as not to hinder the traveling of the can body (63).
It is located above the transition path of (63).

The linear thermoplastic resin material (5) drawn from the drum (4) passes through the front of the first burner (31) by first and second two guide rollers (41) and (42). First pressure roller (2
Guided to 1). The first guide roller (41) is such that the can body (63) moves downstream from the standby position in FIG. 1 and the rear end of the can body (63) is the most downstream side beyond the fourth pressure roller (24). When you move to
It is arranged further downstream so as not to collide with the can body (63), and the thermoplastic resin material (5) drawn from the drum (4) is inverted and guided upstream in the transition path of the can body (63). Second guide roller
Transfer to (42). The second guide roller (42) is located slightly upstream of the first burner (31) in the transition path of the can body (63), and is made of a thermoplastic resin material from the first guide roller (41). (5) is inverted and guided to the first pressure roller (21). A thermoplastic resin material is provided between the second guide roller (42) and the first pressure roller (21).
(5) passes near the tip of the first burner (31).

However, when the thermoplastic resin material (5) moves from the second guide roller (42) to the first pressure roller (21), the first
It is heated and softened by the burner (31). The can body (63) moves downstream with the welding seam (61) being positioned directly below, while resting on the moving table (13). During this time, the second to fourth burners (32) (33) (34)
By (35), the thermoplastic resin material (5), the non-resin protection portion (62) of the can body (63), and the end of the resin protection layer (7) are heated and softened. Immediately before the tip of the can body (63) reaches the first pressure roller (21), it passes through the second burner (32), whereby the non-resin-protected portion (62) of the can body (63) is preheated. From the first pressure roller (2
Then, the welding seam (61) moves while being pressed between the receiving rollers (12) and the pressure rollers (21) (22) (23) (24).
During this time, the second to fourth burners (32), (33), (34), and (35) are used to form the thermoplastic resin material (5), the non-resin protection portion (62) of the can body (63), and the resin protection layer (7). The ends are heated and softened.

The thermoplastic resin material (5) is slightly crushed by the first pressure roller (21) into a semicircular shape as shown in the lower diagram of FIG. 2C. When passing through the second pressure roller (22), the non-resin protection portion (62) is squashed flat so as to greatly expand in the width direction. After filling the bottom of the step between the end portion (71) of the resin protection layer (7) and the non-resin protection portion (62), the step is climbed. Therefore, the thermoplastic resin material (5) and the non-resin protection part (62)
There is no room for air to accumulate between them, and no air bubbles remain. Further, there is no problem that the coating is thinned or cut off at the edge of the metal plate at the joint, which is difficult to avoid with the conventional repair material having high fluidity. Can body (63)
When passing through the third pressure roller (23) and the fourth pressure roller (24), the flatness of the thermoplastic resin material (5) is further increased, and the flatness of the thermoplastic resin material (5) is increased on the end portion (71) of the resin protective layer (7). The resin film (8) which spreads by the above is formed. When the can body (63) passes through the fourth pressure roller (24), the thermoplastic resin material (5) is cut at the upstream end of the can body (63). This cutting may be performed manually or the cutter may be automatically cut when the cutter comes and goes in the transition path of the thermoplastic resin material (5). When the cutting of the thermoplastic resin material (5) is completed, the roller row (2) rises, and the can body (63) returns to the original position on the upstream side.
The new can body that has been completely repaired is replaced with a new one that has not been repaired, and the same operation as above is repeated.

During pressurization by the pressure roller row (2), there is no danger of air being entrapped in the thermoplastic resin material (5). In this respect, neither bubbles nor pinholes are generated in the resin coating (8). . The resin pressing layer is formed by the fourth pressure roller (24) having no groove.
The thickness of the resin coating (8) pressed in a state of overlapping with the end of (7) does not become thinner than the thickness of the resin protection layer (7), and the non-resin protection part (62) The repair effect is enhanced without causing partial breaks or thin portions in the coating resin for protecting the resin. Because the non-resin protection part (62) of the can body is preheated, it is well compatible with the thermoplastic resin material (5) that has been softened by heating. Since the pressure is applied to the protection portion (62), the bonding strength between the non-resin protection portion (62) and the thermoplastic resin material (5) increases. Resin protective layer
The end (71) of (7) is also softened by heating, and when the softened thermoplastic resin material (5) is put thereon and pressed, the resins are welded and bonded together. In addition, conventional repair materials may be modified,
In many cases, extruded products of various known resins as well as modified synthetic resins are used as repair materials in the present invention, although in many cases the original properties of the resin are impaired by making them liquid or particulate in advance. Therefore, it is possible to select an optimum adhesiveness and chemical resistance.
When the repaired can body (63) returns to the original position, if there is a risk that the thermoplastic resin material (5) may be blown by the burner (31),
The burner (31) may be ON / OFF controlled by a solenoid valve or the like.
In this case, the control of the pilot device can also be electrically linked with the gas supply to the burner.

[0021]

Embodiment 1 The resin protective layer (7) on the inner surface of the can body (63) is coated.
Formed Example Thermoplastic resin material (5) Canister body of modified polyethylene wire rod having a diameter of 3 mm (63) Made of chrome-plated thin steel plate, length 400 in the axial direction
mm, thickness 0.4 mm, epoxy resin thickness 12μm on the inner surface is coated, placed the width of the non-resin protective portion (62) transport device is 12mm (1) is a can body (63) to the moving base (13) 12m (3) Heating and pressurizing roller train (2) First pressurizing at a temperature of 200 ° C. in a range of 50 mm centering on the non-resin protection part (62) of the can body (63) by a burner direct fire The circumferential groove (21a) of the roller (21) is an arc-shaped bottom groove having a maximum depth of 2 mm and a width of 3.5 mm. The circumferential groove (22a) of the second pressure roller (22) is an arc having a maximum depth of 1 mm and a width of 15 mm. Bottom groove The circumferential groove (23a) of the third pressure roller (23) is 0.5 mm, width 20 mm
The fourth pressing roller (24) has no groove. The obtained repair resin film is a repair film having a thickness of 0.1 mm and a width of 22 mm.

The blank shown in FIG. 6 was cut out of each of the six can bodies (63) manufactured according to Test Example 1 by cutting a blank having a width of 100 mm and a length of 400 mm centering on the repaired portion, and cutting the blank to a length of 200 mm. I made 12 pieces and tested them. In the present invention, when the cross-section observation and the performance test were performed, it was very good as follows. . Cross-sectional shape The surface pressed by the pressure roller is flat, and the surface to be bonded to the welded part is formed in conformity with the shape of the irregularities, and no thinning of the coating at the edge of the metal plate was observed (Fig. 3
E). . Cross-cut test None of the repaired resin coating on the welded part (A in FIG. 6), the repaired resin coating on the non-resin protection part (B in FIG. 6), and the resin protection layer (C in FIG. 6) did not peel off. In the grid test, 10 × 10 grids are formed by making a grid-like cut at 1 mm intervals with a cutter so that the test layer reaches the metal surface. After the cellophane tape is pressed from above, the tape is peeled off, and the adhesive strength is determined based on how many 1 mm square resin films are peeled off together with the tape. A pass is judged as zero peeling. . T-peeling test None of the repaired resin film on the welded portion (A in FIG. 6), the repaired resin film on the non-resin-protected portion (B in FIG. 6), and the resin protective layer (C in FIG. 6). In the T peel test, as shown in FIG. 7, a parallel cut is made on the test layer with a cutter so as to reach the metal surface at a distance of 10 mm, and the test layer is cut and raised 10 mm from the starting point of the cut to make a right angle. The force at the time when the 10 mm-wide tape-like film is peeled off is measured. In this case, peeling is not possible because the film cannot be peeled and the film is destroyed, and it is judged as acceptable. . Repeated bending test (repeated until the test piece cuts perpendicular to the welding direction) Repair resin coating on the welded part (A in Fig. 6), Repair resin coating on the non-resin protection part (B in Fig. 6), Resin protective layer No peeling was found in any of (c) in FIG. . Chemical Resistance After sealing the back surface and the edge of the test piece with wax, the test piece was immersed in the following chemicals a to f, and kept at 45 ° C. in a constant temperature bath to perform an acceleration test for 3 weeks. “No abnormality” in the results shown below indicates the same results as the above test results, and also indicates that no rust was generated, no coloring, and no change in the solution was caused. Chemicals a. 5% HCl aqueous solution b. 5% NaOH aqueous solution c. Aqueous ammonia d. 96% ethanol e. 3% saline f. 23% aqueous solution of Raipon F (trade name, household detergent)

Chemical Welded area (Fig. 6a) Peripheral area (Fig. 6b) Coating resin protective layer (Fig. 6c) a No abnormality No abnormality No overall rust b No abnormality No abnormality No overall rust c No abnormality No abnormality Rust Occurrence d No abnormality No abnormality No spot rust e No abnormality No abnormality rust occurrence f No abnormality No abnormality Point rust

[0024]

Example 2 A can body was made of a metal substrate (60) having a thickness of 0.32 mm.
The length of the welding seam (61) was changed to 350 mm. Other conditions were tested in the same manner as in Example 1. The results obtained were exactly the same as in Example 1.

[0025]

Embodiment 3 The resin protective layer (7) on the inner surface of the can body (63) is formed by lamination.
In place of the coating resin protective layer of Example 1, a resin protective layer formed by laminating a linear low-density polyethylene film was formed on the inner surface of the can body, and a modified synthetic resin wire was used in the same manner as the laminated film. Grade linear low-density polyethylene. Further, the same repair was performed while cooling the pressure roller with water. Example 1 from the obtained 6 cans
The same test piece was taken and tested in the same manner. The results obtained were as follows. . Cross-sectional shape The cross-sectional shape was such that the surface pressed by the pressure roller was flat, and the surface to be bonded to the welded portion was formed in the shape of irregularities, and no thinning of the coating at the steel plate edge was observed. In addition, the repair coating and the laminated film were completely melted, and it was difficult to recognize the interface (FIG. 3).
E). . Cross-cut test None of the repaired resin coating on the welded part (A in FIG. 6), the repaired resin coating on the non-resin protection part (B in FIG. 6), and the resin protection layer (C in FIG. 6) did not peel off. . T-peeling test None of the repaired resin film on the welded portion (A in FIG. 6), the repaired resin film on the non-resin-protected portion (B in FIG. 6), and the resin protective layer (C in FIG. 6). . Repeated bending test (repeated until the test piece is cut perpendicular to the welding direction) No abnormality such as floating in the welded part, peripheral part, and laminate part. Chemical resistance The same test as in Example 1 was performed, and the following results were obtained.

Chemical Welded part (Fig. 6a) Peripheral part (Fig. 6b) Coating resin protective layer (Fig. 6c) a No abnormality No abnormality No abnormality b No abnormality No abnormality No abnormality c c No abnormality No abnormality No abnormality d No abnormalities No abnormalities No abnormalities e No abnormalities No abnormalities No abnormalities f No abnormalities No abnormalities No abnormalities

[0027]

Example 4 In the same manner as in Example 3, the thickness of the coating film formed by changing the pressing pressure of each of the grooved pressing rollers and the pressing pressure of the non-groove pressing roller was 20 mm to 40 mm in width. The thickness could be arbitrarily adjusted from 0.01 mm or less to 0.03 mm or more. The cross-sectional shape at this time was the same as in Example 3. In all of Examples 1 to 4, the surplus amount other than the amount of the film formed was extruded out of the edge of the can by a roller in order, and could be easily cut and removed. Further, in the present invention, in a can having a resin protective layer formed by lamination (especially a can using a polyethylene-based laminated film), the film and the repair resin that are laminated beforehand at the time of forming the film are mutually melted and integrated. As a result (FIG. 3E), it was possible to produce a perfectly repaired weld can.

The apparatus of the present invention is characterized in that a synthetic resin wire having a specific cross-sectional shape and a cross-sectional area is re-formed into another shape such as a coating, and is adhered or fused to a substrate while being formed. Therefore, the shape and layout of the equipment and the shape and number of the pressure rollers are not limited. Also, the groove shape of each pressure roller of the pressure roller row (2) is not limited to the above-mentioned one. For example, all the pressure rollers have no groove, and the pressing force is increased toward the downstream roller. The shape and the number of rollers are not limited as long as the linear thermoplastic resin material (5) can be gradually crushed. The cross-sectional shape, cross-sectional area, and material of the synthetic resin wire used are determined by the required film thickness, shape, quality, and the like, and are not limited. That is, the technique of the present invention can be used not only for repairing welding cans, but also for welding cans and adhesive cans, as well as for repairing cracks and scratches, filling holes, and the like. FIG.
Shows a repair device when the seam is located at the corner of the square can, receiving roller (12a) having a circumferential groove (12b) along the corner of the can and side receiving rollers (12c) (12c ) To support the can body (63), and squeeze the thermoplastic resin material gradually in the same manner as described above with the pressure roller row (2a). Pressure roller row
The groove shape of each pressure roller in (2a) may be changed stepwise.
In the practice of the method of the present invention, the welding seam of the can body (63)
At the same time as (61) and its peripheral part are preheated, the adhesive strength can be increased by subjecting the part to flame plasma treatment.

[Brief description of the drawings]

FIG. 1 is a front view of a repair device.

FIG. 2 is an explanatory diagram of a pressure roller and a thermoplastic resin material that is deformed by being pressed by the roller.

FIG. 3 is a cross-sectional view comparing a repair part of the present invention with a conventional repair part.

FIG. 4 is a perspective view of the can body before repairing in which a part of the can body is broken.

FIG. 5 is a perspective view of the can body after the repair.

FIG. 6 is a front view of the test piece.

FIG. 7 is an explanatory view of a T peel test method.

FIG. 8 is an explanatory diagram of a method for repairing a square can.

[Explanation of symbols]

 (1) Conveying device (2) Pressure roller row (3) Heating device (5) Thermoplastic resin material (61) Weld seam (62) Non-laminated part (63) Can body (7) Resin protective layer (71) End Department

Claims (5)

[Claims] 1. A can body having a resin protective layer (7) formed on its inner surface by lamination, coating or the like, and a seam of the can body and a belt-shaped non-resin protective portion (62) formed on both sides of the seam. In the method of repairing the seam, the non-resin protection portion (62) of the can body and the resin protection layer on both sides of the non-resin protection portion (62)
The ends (71) and (71) of (7) are heated and softened, and a linear thermoplastic resin material (5) having a constant cross-sectional shape is heated and softened over the entire length, and this is joined to the seam of the can body. The linear thermoplastic resin material (5) is gradually flattened so as to cover the non-resin protection portion (62) and the end portions (71) (71) of the resin protection layer (7) while being disposed along. A method of repairing a seam joint of a can body, which crushes and extrudes air between the resin material and the surface of the can body to cover a non-resin protection portion (62) including a seam of the can body to form a resin film (8). . 2. An end portion (71) of the resin protective layer (7) is heated and melted, and the thermoplastic resin material (5) softened by heating is coated on the non-resin protective portion (62) of the can body. The method for repairing a seam joint of a can body according to claim 1, wherein the resin coating (8) and the resin protective layer (7) are welded and integrated. 3. A transfer device for transferring a can body in an axial direction thereof.
(1) and a plurality of pressure rollers (21) (22) arranged in a line on a transition path of the can body (63) conveyed by the conveying device (1) and capable of pressing a seam of the can body (63). ) (23) (24) and a linear thermoplastic resin material to the pressure roller (21) through which the can body (63) passes first.
A guide roller (4) (41) for supplying and guiding (5), and a joint (6) of the can body fed to the thermoplastic resin material (5) and the pressure roller (21).
1) The heating device (3) for heating the vicinity, the plurality of pressure rollers (21) (22) (23) (24), the pressure roller (21) to press the can body first A resin coating and repairing apparatus for a seam of a can body, characterized in that the pressing surface is changed stepwise so that the thermoplastic resin material (5) can be crushed flat in order. 4. A transfer device (1) for transferring a can body, and a plurality of transfer devices arranged in a line on a transition path of the can body (63) transferred by the transfer device (1) and capable of pressing a seam of the can body. Transfer of the can body to the pressure roller (21) through which the can body (63) first passes the pressure roller (21) (22) (23) (24) and the linear thermoplastic resin material (5) Guide rollers (4) and (41) for supplying and guiding so as not to interfere with the heating, and a heating device () for heating the vicinity of the seam (61) of the can body (63) sent to the thermoplastic resin material (5) and the pressure roller ( 3), the plurality of pressure rollers (21), (22), (23), and (24) are formed by sequentially pressing the thermoplastic resin material (5) in order from the pressure roller (21) that presses the can body. A resin coating and repairing apparatus for a seam joint of a can body, characterized in that the pressing force is changed stepwise so as to be able to be crushed more flatly. 5. A can in which a resin coating (8) is applied to a strip-shaped non-resin protection portion (62) including a seam of a can body having a resin protection layer (7) formed on the inner surface by lamination, coating or the like. (8) is welded to the ends (71) and (71) of the resin protective layer (7) and has the same thickness as the resin protective layer (7) or the resin protective layer.
(7) A can having a thickness larger than that of (7) and a flat surface.