JPS5871122A - Preparation of metallic container having joint by thermal bonding - Google Patents

Abstract

PURPOSE:To bond the joint of a container effectively by such an arrangement wherein the edge of an upper part of container material including a metal is coupled with that of a lower part of the same material by means of a thermosetting resin, a coil is placed in the vicinity of the edge of said material above the joint and another coil is placed similarly below the joint and the direction of a current of one coil is opposite to that of another coil, and the joint is effectively heated by high frequency induction heating. CONSTITUTION:Both edge portions 3, 4 are coupled together at a portion 5a which becomes a joint by means of a layer of adhesive 11a, and locally they are electrically insulated. A high frequency induction heating coil 14 is arranged outside the joint 5a. In other words, a side wall portion 6 connected to an intenal open edge portion 3 faces with a coil 15 wherein a current flows in the direction from the top to the bottom in the figure at a fixed point of time, and a side wall portion 8 connected to an outer open end portion 4 faces with a coil 16 wherein a current flows in the direction from bottom to top at the same point of time and the joint 5a is positioned midway between both coils 15, 16. The joint cak be effectively heated by causing a current to flow through the high frequency induction heating coils.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a gold JFAW vessel having a seam formed by thermal bonding, and more specifically, the present invention relates to a method for manufacturing a gold JFAW vessel having a seam formed by thermal bonding, and more specifically, the both edges of a container material, which are engaged through an adhesive resin layer, are connected to a high-frequency induction heating coil. This invention relates to a method for manufacturing a metal container, which comprises forming a joint by thermal bonding by efficiently heating the container.

High-frequency induction heating is a heating means widely used for heating metal moons, and is also widely used for manufacturing metal containers with seams formed by thermal bonding such as adhesive ends. , the high-frequency magnetic field from the high-frequency induction heating coil is blocked by the metal material, so in conventional technology, the resin adhesive applied to the edge of the container material is overlapped with light and subjected to high-frequency induction heating. There is a method of overlapping both ends through a molten adhesive layer, and finally pumping the overlapping part while cooling to form a seam, and a method of forming a joint by overlapping the ends of the container through a resin adhesive layer. A method is adopted in which the outside of both ends is heated by high-frequency induction, and the ends are thermally bonded by heat transfer from the outside.

However, although the former method can be conveniently applied when thermal bonding is performed by pressing both ends in the overlapping direction, such as in lap side seam cans where the seam extends straight in the axial direction, , an upper body and a lower body each consisting of a cup-shaped molded body formed by drawing or drawing-ironing a metal material are fitted at their circumferential open ends via an adhesive to form a container. When forming
It is difficult to apply because the axial pressing force during fitting causes the 9-bath fusion eyelid layer to leak out of the joint or cause scratches on the open end.

In addition, in the latter method, since the high-frequency magnetic field is blocked at the outer end of the seam, the inner end of the seam is heated only by heat conduction. Layering: Because the thermal conductivity is significantly poorer than that of metal, it takes an extremely long time for thermal bonding. A temperature gradient is inevitably formed in which the temperature is lower than the temperature, resulting in a defect that uniform heating becomes difficult. Especially gold h
When the I quality of the A stack is a ferromagnetic material such as steel, the inner end portion is not easily heated.

Therefore, an object of the present invention is to simultaneously heat both edges of a container material engaged through an adhesive resin layer from the outer edge and the inner 91M portion by high-frequency induction heating. All methods are provided below.

Another object of the present invention is that when manufacturing a metal container having a seam formed by thermal adhesion, it is possible to heat the thermal adhesive located between the two engaged ends to form the seam using high-frequency induction heating within a very short time. There is a whole way to offer you.

Still another object of the present invention is to provide a method in which both ends of a material with an adhesive layer interposed therebetween can be heated to an arbitrary temperature.

Still another object of the present invention is to fit together an upper body and a lower body each made of a metal seamless cup-shaped molded body through an adhesive layer at their circumferential open ends. The present invention aims to provide a method for efficiently heating this adhesive layer from the outside of the fitting portion by high-frequency induction heating.

According to the present invention, in a container manufacturing method that involves joining both ends of a container material made entirely of metal through a seam formed by thermally bonding resin, both ends are engaged through a layer of thermally adhesive resin. In addition, the part that should be a joint where both ends are locally insulated,
The material connected to one end and the material connected to the other end are faced to coil parts with opposite current directions, and the part to be the joint is located approximately in the center of both coil parts, and high-frequency induction heating is performed. There is provided a method for manufacturing a metal container, characterized in that the coil is energized and a thin current is passed through each of the ends to heat a portion of both ends.

As already pointed out, the present invention involves fitting an upper body and a lower body, each of which is a seamless cup-shaped molded body made of metal, through an adhesive layer at their circumferential open ends. This adhesive layer is efficiently heated by high-frequency induction heating from the outside of the mating part, and is particularly useful for manufacturing a complete bottle-shaped metal container with a circumferential side seam. The invention will be explained below using this container as an example, but the invention is of course not limited to this case.

In FIG. 1 showing an example of a metal bottle according to the invention, this bottle includes a lower body 1 made of a seamless cup-shaped molded body made of metal such as a tin-plated steel plate, and a seamless cup-shaped molded body made of metal. These cup-shaped molded bodies have an open end 6 and an open end s4 that are joined together to form a circumferential side seam 5. integrated into the shape.

In this embodiment, the lower body 1 consists of a tall thin side wall portion 6 formed by drawing and ironing a metal material at a high degree of 6 degrees, and a thick bottom portion 7 which has not undergone substantially all the ironing process. The upper body 2 is also a cup consisting of a tall thin side wall 8 and an upper wall 9 formed by the same molding as the lower body.The height of the side wall 8 of the upper body 2 is determined by the seam. 5, or slightly larger than the width of the joint.The upper wall 9 of the upper body 2 has an upwardly convex tapered surface, and the center of the upper wall 9 has a tapered surface for filling the contents. A spout 10 for dispensing is formed.

In the specific example shown in FIG. 1, the open end 6 of the lower body 1 is narrowed to a smaller diameter than the rest of the body wall by neck-in processing in the vicinity of the open end 6. It is fitted into the open end 4 of the large diameter upper body. A thermal adhesive layer 11 is provided between the outer surface of the open end 6 of the lower body and the inner surface of the open end 4 of the upper body, and the bonding between the lower body and the upper body,
Fixation is taking place. A portion of the adhesive 11 protrudes from the seam 5 and is attached to the cut edge 12 of the metal material located inside the seam.
From the viewpoint of corrosion resistance, it is desirable to form a coating layer 16 on the metal.

In the metal container having the above-described structure, only an extremely small spout 10 is formed in the upper body 2, and therefore, after the upper body 2 and the lower body 1 are fitted together, this fitting assembly is It will be understood that it is virtually impossible to insert a special heating mechanism etc. into the interior of the three-dimensional body, and therefore, the only heating of the fitting part is heating from the outside.

According to the present invention, a high-frequency induction heating coil is positioned outside the fitting portion in a specific manner and energized, thereby
Not only the open end portion 4 located on the outside but also the open end portion 6 located on the inside can be efficiently heated and bonding can be performed within a very short time.

In FIG. 2 for detailed explanation of the present invention, in a portion 5cL to be a seam, both ends 6 and 4 are mechanically engaged by fitting through an adhesive layer 11α, and this Both ends 6 and 4 are electrically insulated at least locally by adhesive #11c.

There is a total of 1
The high-frequency induction heating coils indicated by 4 are arranged in the following positional relationship. That is, the side wall portion 6 that continues to the inner open end portion 3
, the side wall portion 8 facing the coil portion 15 in which the current flows vertically from top to bottom at a certain point in the drawing, and connected to the open end 4 on one side, the current flows at the same point in the drawing. Coil part 1 flowing vertically from bottom to bottom
A portion 5α that faces coil portion 6 and is to serve as a seam is located approximately midway between both coil portions 15 and 16. Although the coil portions 15 and 16 are only shown in cross-section in the figures, it should be understood that they form continuous loops substantially perpendicular to the drawings.

In the above-mentioned positional relationship, the high frequency induction heating coil 14
When a high-frequency current is applied to the side wall portion 6 facing the coil portion 15, tN of the coil portion.

A thin current 17 is induced which runs in the opposite direction to the open end portion 6 but in the same direction.

Similarly, in the side wall portion 8 facing the coil portion 16, an eddy current 18 is induced which is opposite to the current direction of the coil portion and passes through the open end portion 4 in the same direction. These vortices fi 17 and 18 are induced in such a way that the current density 181 is low in the portions of the side walls 6 and 8 and high in the portions of the open ends 3 and 4, and as a result, the current density lKt is Not only the open end 4 located on the inside but also the open end 6 located inside is heated strongly. For this purpose, the high-frequency conductive heating coil 14 is formed such that the current density in the coil portions 15 and 16 is sparse. In the drawings, reference numeral 19 is a magnetic core made of a magnetic material such as ferrite, which strengthens the electromagnetic coupling between both coil portions 15 and 16 and the material side wall 6.8, which can be used for rounding to increase heating efficiency. ing.

According to the present invention, as explained above, the flat wave induction 47IO
By performing electromagnetic coupling between the heating coil and the metal material to be heated not at the portion where both ends of the material are overlapped, but between the side wall portions 6 and 8 which are separated from each other rather than this overlapped portion, This makes it possible to heat both the inner and outer ends 6.4 efficiently, and also in a short time because both the inner and outer ends 6.4 are heated with the adhesive layer in between. Moreover, uniform heating is possible. A short heating time has the advantage that the amount of molten adhesive overflowing is reduced.

In the present invention, in order to heat the entire circumferential fitting part with the above-mentioned high-frequency induction heating coil, a large number of high-frequency induction heating coils are arranged so as to substantially cover the surrounding metal of the circumferential fitting part. However, there are two methods: a method in which induction heating is performed with the fitted object of the upper and lower bodies stationary, a method in which one or more high-frequency induction heating coils are arranged and induction heating is performed without fully rotating the fitted object of the upper and lower bodies, and a long method. A method of heating the fitting portion by rotating and moving it along the flat coil, a combination method of these methods, etc. may be employed as appropriate.

As for the high frequency current applied to the coil, any current used for induction heating of plums can be used; for example, generally speaking, a high frequency of 10 KHz to 500 KHg is preferably used. The input to the heating coil also varies considerably depending on the size of the container, the required temperature and heating time - and cannot be generally specified.

As an example, when joining a circumferential seam container with a diameter of 110.6mm using a polyester thread adhesive, the input cuff KW is 0.
．． It was confirmed that the thermal bonding process was completed in an extremely short time of 6 seconds.

According to the present invention, it is also possible to heat the outer end and the inner end to the same temperature,
It is also possible to heat these at different temperatures.

In the specific example shown in FIG. 3-A, the thickness t of the outer body 2
. and ti of the inner body 1 are equal and the heating coil 15.
If the gaps between the outer end 4 and the outer end 4 are equal, the temperature rise will tend to be slightly higher at the outer end 4. In this case, by inserting the ferrite core or M&21 between the coil portion 16 of the heating coil 14 and the outer body 2, the temperature T of the outer end 4 can be adjusted. and the temperature Ti of the inner end 6 can be made equal. In this case, if a ferrite core is used, the heating efficiency will be higher because the power loss is lower than that of a copper plate. T can also be achieved by making the total distance between the outer body 2 and the coil portion 16 larger than the distance between the inner body 1 and the coil portion 15. It is possible to heat the material so that = Ti.

In the specific example shown in FIG. 3-B, the distance between the outer body 2 and the coil portion 16 is made wider than the distance between the inner body 1 and the coil portion 15, and the distance between the outer body 2 and the coil portion 16 is By inserting a ferrite core or a copper plate 20 between them, it is possible to heat with a temperature relationship of Ti'')To.Of course, if this positional relationship is reversed, To>Ti
It is also possible to heat with the following temperature relationship.

In the specific example shown in FIG. 3-C, by lowering the position of the heating coil 14 relative to the fitting part 5α, the thin current induced in the outer end 4 is reduced, and the 7'j)T by suppressing the temperature rise.

We make sure that this relationship is established. Conversely, in Fig. 3-C, by raising the position of the coil 14 relative to the fitting portion 5cLVc, the eddy current induced in the inner end 6 is reduced, and the temperature rise in the inner end 6 is reduced. It can be suppressed.

131 In the present invention, any material that can be melted, softened, or activated by heat and exhibits adhesion properties can be used as the adhesive layer, such as polyester, polyamide yarn, acid-modified polyolefin, etc. Plastic resin adhesives are advantageously used, but are of course not limited thereto.

Materials for containers include Il! such as aluminum. ¥! All metal-containing materials such as metal, tinplate, nine-free steel, other various surface-treated steel plates, and black plates are used, even if these materials are painted with 1.1 each rod paint. Equal differences are not supported.

Furthermore, even if this material is a laminate of metal foil and glass film, if this plastic film exhibits heat-sealing properties, it is natural that it can be used as an adhesive.

The present invention is suitably applied to the production of the above-mentioned container with a circumferential joint. For example, as shown in FIG. 23
6 can be advantageously used for lock seam bonding via adhesive layer 11, and 14- is also advantageous for use in heat sealing the periphery of the lid and the flange of the body via thermal adhesive. Can be used.

The invention is illustrated by the following example.

A modified vinyl paint is applied to the inner and outer surfaces of the base plate thickness 0.23 dragon aluminum plate C6004 material H19) with a total coating amount of 18
0ml/dm2.80m? / dm", then punched out into a disc with a diameter of 250 mm, and molded into a syllable by normal press processing, with an inner diameter of 110.60 io+ at the edge of the joint and a diameter of 60 mm at the center. The entire upper body with a spout was fabricated.

On the other hand, a lower body having an outer diameter of 110.50 mrs at the edge of the joint was produced by completely punching out a disk with a diameter of 250 mm from the same painted plate and forming it by press working.

Over the entire circumference of the edge of this lower body, its outer surface constraint 6 t
The adhesive was completely applied in the following manner to a width of 2 nm on the inner surface. That is, in Example 12, the entire lower body of powdered nylon 12 was masked so that only 6 outer edges and 2 inner edges were exposed, and then static coating was performed, and then those areas were heated with an infrared heater. Melt the powder to about 85μ
An adhesive film was formed with a film thickness of m.

After fitting the upper body prepared as above and the lower body coated with adhesive, a heating process and a cooling process are performed in the same steamer to melt the adhesive in the mating part and solidify it by cooling. H with the upper body and lower body joined
A total of 8t approximately 2000111/metal containers were manufactured. In addition,
In the heating process, the member to be heated is rotated at 480 rpm and heated for 0.6 seconds with an input of 7KW, and in the cooling process, as soon as the heating is completed, compressed air is sprayed onto the fitting part for 1 second using a nozzle metal to cool it. I did it.

1. The shape of the heating coil in the heating process is 3-A.
, 3-B, 3-C, and 7, the diameter of the conductor of the heating coil 15, 16 is 4 mra, and the number of turns of the flat spiral heating coil is ta-coupled to the upper member 2 and lower member 1. has 5 turns, the width Wc is 25 mm, and the width Wg of the hollow part is 20 ms.

The cooling nozzle of the outer member is placed on the opposite side of the fitting part of the container corresponding to the heating coil so as to surround the fitting part.The cooling nozzle of the inner member is inserted through the opening of the outer member, and the cooling nozzle of the inner member It is installed to cool the corresponding position.

The details of the heating process and cooling process adopted on each side are as follows.

Example 1゜So that the temperature rises of the outer member and the inner member are equal,
The heating coil was set in a state where it was lowered by 2 degrees (Δl=2 degrees) from the center of the center metal fitting part of the heating coil. In the cooling process, air was blown onto the outer and inner members.

The temperature of the fitting portion at this time is shown in FIG. The curve α is the temperature of the fitting portion of the outer member and the inner member, and the curve α is the temperature of the adhesive.

At the end of heating 1. The temperature of the fitting portion of the outer member and the inner member was both 260°C, and the temperature of the adhesive was 195°C.

The time t2 required for the adhesive to reach the solidifying temperature of 145° C. was 0.5 seconds after the end of heating.

The temperatures of the outer member and the inner member at the time when the adhesive solidified were the same, 115°C. Therefore, -17= No more than necessary pressing force is applied to the adhesive, the adhesive is not extruded from the fitting part, and no tensile stress is applied to the adhesive even if the fitting part reaches room temperature.

Example 2 The center of the heating coil was set 1 m1 from the center of the fitting part of the outer member so that the temperature of the fitting part of the outer member was higher than that of the inner member.
The heating coil was set in a state where it was raised by 1 (Δ/−1−1 mm).

At the end of heating, the temperature of the outer member of 1=11 was 245°C, the temperature of the inner member was 215°C, and the temperature of the adhesive was 195°C.

The time required for the adhesive to reach the solidifying temperature of 145° C. was 0.5 seconds after the end of heating. At this point 1=1. The temperature of the inner member is 110°C and the temperature of the outer member is 120°C. Since the temperature of the outer member is slightly higher, the tightening force of the adhesive will be weaker, but this degree of temperature difference is not practical for practical purposes. No problem.

Example & In order to make the temperature of the fitting part of the outer member lower than that of the inner member, the center of the heating coil was set 18-31 degrees lower than the center of the fitting part (△1--3). Set up the heating coil.

The temperature of the outer member at the end of heating (1=t+) is 220°C,
The temperature of the inner member was 240°C and the temperature of the adhesive was 195°C.

The time required for the adhesive to solidify is 0.5 minutes from the end of heating.
It was seconds later. At this time, the temperature of the outer member was 115℃,
The temperature of the inner member was 120°C.

In this case, since the temperature of the outer member is slightly lower than that of the inner member, a tightening force may act on the adhesive and the molten adhesive may be extruded, but this does not pose a practical problem.

[Brief explanation of the drawing]

Fig. 1 is a side cross-sectional view of a metal container having a circumferential side seam formed by thermal bonding; Fig. 2 is a side cross-sectional view of a high-frequency induction heating coil and the container for detailed explanation of the present invention; Fig. 3-A; , FIG. 3-B and FIG. 3-C are partially enlarged side views showing several examples of arrangement of high-frequency induction heating coils. FIG. FIG. 5 is a diagram showing a one-hour temperature curve during heating and cooling of each part of the seam in Example 1. Reference number 1 is the lower body, 2 is the upper body, 6 and 4 are the open ends, 5 is the seam, 5α is the fitting part, 6 and 8 are the side walls, 11.1
1cL is an adhesive layer, 14 is a high frequency induction heating coil, 15
and 16 are coil portions in which current directions are opposite to each other, eddy currents 17 and 18 are in opposite directions, and 19 is the entire magnetic core. Patent applicant Akira Kishimoto Agent Patent attorney Ikuo Suzuki ('1 Figure 1 0 Continued from Figure 2 page 1 ■ Applicant Akira Kishimoto 26-130-4439 Kamaritani-cho, Kanazawa-ku, Yokohama-shi

Claims (1)

[Scope of Claims] (1) In a container manufacturing method that involves joining both ends of a container material containing metal through a seam formed by thermally bonding resin, the both ends are joined through a layer of thermally adhesive resin. The part that is to be a joint where both ends are locally electrically insulated is
- The material connected to one end of the coil and the material connected to the other end face the coil parts with opposite current directions, and the joint part is located approximately in the center of both coil parts, so that high frequency induction can be achieved. A method for manufacturing a metal container, comprising heating both ends by energizing a heating coil and inducing an eddy current passing through each of the ends. ■ The high frequency induction heating coil has a magnetic core in the center,
A coil t [L is engaged around the coil t [L], and both ends to be bonded face the magnetic core, and the material connected to one end and the material connected to the other end have opposite current directions. The method according to claim 1, wherein the high frequency induction heating coil is positioned so as to face the coil portion and a magnetic field is applied thereto. (5) The above-mentioned materials are an upper body and a lower body, each of which is made of a seamless cup-shaped molded body made of metal, and their open ends are fitted together, and the fitted ends are all the above-mentioned high-frequency induction The method according to claim 1, wherein the layer is bonded by heating with a heating coil.