JPS58189280A - Preparation of metallic container - Google Patents

Abstract

PURPOSE:To prepare a metallic container having a circumferential joint bonded with an adhesive, by forming an assembled container consisting of upper and lower hollow bodies fitted with each other via a hot-melt adhesive and heating the fitted part with opening kept in closed state. CONSTITUTION:Lower hollow body 3 with a bottom and upper hollow body 2 with an opening are fitted together at the opened ends 2b and 3b, with a hot- melt adhesive layer formed on the fitted part to fabricate an assembled container 11. The assembled container 11 is mounted between a 1st member 16 and a 2nd member 13 facing each other at a fixed distance. The fitted part 7 is heated, with the opening 2a kept in closed state while sliding of opening end in the axial direction due to the filled-in pressurized gas being swelled by heating is prevented by the 1st and the 2nd members 16, 13 so that the adhesive layer 4 may be fused and a metallic container with a circumferential joint and a required height may be prepared.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a metal container, and more particularly to a method for manufacturing a metal container having (1) a peripheral joint portion joined via an adhesive layer.

As shown in FIG. 1, an open end 3b (reduced diameter ) are fitted together via an adhesive layer 4 made of heat-fusible plastic, and the fitting part is heated to a temperature that allows heat-fusibility of the plastic to perform circumferential bonding. When sealing the metal cap 6 by tightening the opening 2a of the metal container 1 formed with the portion 5 using a tightening tool (not shown), if the height of the metal container 1 is uneven, the container may be sealed poorly. (when the height is smaller than the specified value) or containers whose body portion 1a buckles and loses commercial value (when the height is higher than the specified value) are likely to occur. This is because the distance between the mounting plate (not shown) for the metal container 1 and the claw portion (not shown) of the seaming tool is constant regardless of variations in the height of the metal container 1.

However, in the process of manufacturing the metal container 1, during the transfer from the fitting device to the heating device for the fitting portion, slipping in the axial direction may occur in the fitting portion, or the upper (2) portion of the can body 2 may slip in the lower can. Phenomena such as tilting with respect to the body 3 are likely to occur, and even if the heights are aligned at the time of fitting, it is not possible to manufacture the metal container 1 of uniform height by simply heating the fitting part. Have difficulty.

The present invention aims to solve the above technical problems.

In order to achieve the above object, the present invention fits each open end of a lower hollow body having a bottom portion and an upper hollow body having a mouth portion through a heat-fusible adhesive layer to form a fitting portion. A method of manufacturing a metal container having circumferential joints by forming a metal container assembly having circumferential joints, and then heating and melting the adhesive layer by heating the fitting part, the method comprising: forming a metal container assembly having circumferential joints arranged at regular intervals; The metal container assembly is inserted between the first member and the second member facing each other, and the fitting part is heated with the mouth part sealed, and the interior expanded by heating is heated. caused by the pressure of the gas,
The open end through the molten adhesive layer? The present invention provides a method for manufacturing a metal container of a constant height having a circumferential joint portion, characterized in that the axial slippage of the metal container is restricted by a first member and a second member.

The present invention will be described below with reference to drawings showing embodiments.

In FIG. 2, reference numeral 11 indicates that the diameter-reduced open end 3b of the lower can 3 is inserted into the open end 2b of the upper can 2 with an adhesive layer 4 interposed therebetween. This is a metal container assembly formed by forming a joining part 7. The upper can body 2 in this example is
A cup-shaped body is formed by drawing a relatively thin (e.g., about 0.15 to 0.30 mm) metal blank (e.g., made of a tin-plated steel plate or an aluminum alloy plate with at least the inner surface coated). It is made by forming a mouth part 2a by burring the bottom part, and forming a bead part 2a1 for fixing the metal cage 6 to the end of the mouth part 2a. - The inferior lower can body 3 is made by drawing a metal blank of the same type as that used for the upper can body 2.
After processing to form a cup-shaped body having the same outer diameter as the upper can body 2, the opening end of the cup-shaped body is reduced in diameter to form a reduced-diameter portion 3b. It is made by forming an adhesive layer 4 of adhesive plastic. In the case of FIG. 2, in order to protect the end face of the reduced diameter part 3b (which is a cut edge and metal is exposed), the adhesive layer 4 also covers the end face and the upper part of the inner peripheral surface of the reduced diameter part 3b. Covered.

As the heat-fusible plastic, a thermoplastic plastic having a relatively low melting point and a polar group, such as modified linear polyester, nylon 12 or nylon 11, or acid-modified polyolefin, is preferably used. The adhesive layer 4 may be formed by powder coating or slurry coating (drying and solidifying after coating), but it is preferable to form the adhesive layer 4 by heat-sealing it to the reduced diameter part 3b of the plastic Teso. This is the most preferred method since it provides an adhesive layer free of defects such as pores.

The fitting is performed using a suitable fitting device, such as a fitting die,
This is done by a tight fit. The metal container assembly 11 formed as described above has a heating device 12
The circumferential joint part 5 (see Fig. 1) is transported to a peripheral surface and the fitting part 7 is heated so that the adhesive layer 4 is heat-sealed to the inner peripheral surface of the open end 2b (5) of the upper can body 2. ) is formed.

The heating device 12 includes a mounting plate 13 for the metal container assembly 11, a high frequency induction heating coil 14 (hereinafter referred to as heating coil), and a magnetic core 15 made of ferrite surrounding the heating coil 14. The mounting board 13 includes a mounting part 13a having an inner diameter substantially equal to the outer diameter of the vicinity of the bottom 3a of the lower can body 3, and the metal container assembly 11 is inserted into the mounting part 13a. . Heating coil 14 and magnetic core 1
5 surrounds the metal container assembly 11 at a position where the magnetic flux is best concentrated on the fitting portion 7 of the metal container assembly 11 inserted into the mounting portion 13a, and is supported by a support (not shown); It is arranged.

Reference numeral 16 denotes a sealing device, which has a frame portion 16a1 that can be loosely inserted into the mouth portion 2a of the upper can body, and a bottom surface 16b1 that surrounds the frame portion 16a and has a shape corresponding to the upper surface 2al' of the bead portion 2al. It has a circumferential groove 16b in which the bead portion 2a1 can be loosely inserted. At least the circumferential groove 16
The peripheral surface of b is preferably formed of a material with a small friction coefficient, such as fluororesin or MC nylon, so that the bead portion 2al (6) can slide easily. The sealing tool 16 is moved up and down by a drive device (not shown) via a shaft 17 so that the circumferential groove 16b remains coaxial with the mounting portion 13a.

A plurality of locking shafts 18 are fixed to the mounting plate 13.
The sealing device 16 is lowered and its flange portion 16c is locked onto the upper surface 18a of the locking shaft 18. The height of the locking shaft 18 is
In the locked state, the distance between the bottom surface 13a1 of the mounting portion 13a and the bottom surface 16b1 of the circumferential groove 16b is determined to be equal to the specified height of the metal container 1 to be manufactured.

Normally, the height of the metal container assembly 11 when inserted into the mounting portion 13a is slightly smaller (for example, 0 to 1 smaller) than the specified height, as shown in FIG. , upper surface 2a1' of bead portion 2al and circumferential groove 1
There is a gap 19 between the bottom surfaces 16bl of 6b.

Place the metal container assembly 11 on the placing part 13a, and close the sealing tool 1.
6 is lowered to lock the sealing tool 16 to the locking shaft 18 in the depressed state. At that time, a frame portion 16a is inserted into the opening portion 2a.
is inserted, and the bead portion 2 is inserted into the circumferential groove 16b,
If the upper can body 2 is tilted toward the lower can body 3, the tilt is corrected to ensure coaxiality between the two. When the heating coil 14 is energized in the state shown in FIG. 2 as described above,
The fitting part 7 and the metal in its vicinity are heated, and the adhesive layer 4 reaches its heat-sealable temperature (i.e., a temperature higher than the melting point or softening point of the thermoplastic, usually about 200°C).
above) to melt and soften. At the same time, the temperature of the air within the metal container assembly 11 also rises and tends to expand. The heated air tries to escape from the gap between the mouth part 2a and the side surface of the frame part 16a, but since the gap is extremely small, the amount of escape is limited, and the internal pressure increases (usually 0.1 kg).
/1yn2 (Guno pressure)) Therefore, the open end 2b and mouth 2a of the upper can body 2 slide along the melted and softened adhesive layer 4 and the side surface of the frame part 16a, respectively, and the upper can body 2 Upper surface 2a1' of bead portion 2a1 and circumferential groove 16b
rises until the bottom surface 16b1 of the
.

The correspondingly shaped top surface 2a1' and bottom surface 16b1 come into compressed contact due to the internal air pressure and the pressing force applied to the closure 16, so that the metal container assembly 11 is substantially sealed. Next, when the heating coil 14 is de-energized (the energization time is usually 0.3 to 2 seconds), the heat near the fitting portion 7 rapidly escapes to other parts of the upper can body 2 and lower can body 3 by thermal conduction. , the adhesive layer 4 is cooled to a solidification temperature, and a circumferential joint 5 is formed. However, since the internal air cools slowly, the internal air pressure hardly decreases until the adhesive layer 4 hardens, and the contact between the top surface 2a1' and the bottom surface 16bl continues.

Therefore, a metal container 1 having a circumferential joint 5 and a specified height as shown in FIG. 3 is obtained. Next, sealing tool 1
6 is raised, the metal container 1 is taken out from the mounting plate 13, and sent to the next process.

FIG. 4 shows an example in which the sealing device and the height regulating means are separate parts. The sealing tool 26 is fitted into the mouth part 2a made of plastic such as MC nylon, and has a frame part 26a that can seal the mouth part 2a, and an inner end of the bottom surface 26b1 which is the upper surface (9) 2a1 of the bead part 2al. ' has a flange portion 26b that comes into contact with.

The upper surface 26c of the sealing member 26 is the bottom surface 2 of the flange portion 26b.
It is parallel to 6b1. The height regulating plate 27 is moved up and down by a drive device (not shown) via a shaft 28, and can be locked onto the upper surface 18a of the locking shaft 18 under pressure. The distance in the height direction between the bottom surface 13a1 and the top surface 18a of the mounting portion 13a is determined to be equal to the specified height of the metal container 1.

The metal container assembly 11 fitted with the sealing member 26 is placed on the mounting section 1.
3a, there is usually a parallel gap 2 between the upper surface 26c of the sealing device and the lower surface 27a of the height regulating plate 27.
9 (usually about 0-1 ran).

When the heating coil 14 is energized in the state shown in FIG. 4,
Similarly to the case shown in FIG. 2, the upper can body 2 rises together with the seal 26 due to the internal air pressure, and the upper surface 26c of the seal 26 is raised.
is in contact with the lower surface 27a of the height regulating plate 27, and the upper can body 2
The inclination of the metal container 1 is corrected, and at the same time the height of the metal container 1 is defined.

The present invention is not limited to the above embodiments; for example, the fitting portion 7 may be heated by direct flame heating, infrared heating, or the like. Further, the heating device may heat the metal container assembly 11 while rotating it by placing an arc-shaped heating coil in contact with a part of the circumferential surface without surrounding the entire circumference near the fitting portion. The upper can body and the lower can body may also have any other shape, and may also have side seams such as welds.

According to the present invention, it is possible to manufacture a metal container of a specified height having a circumferential joint with an adhesive using a simple device.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view showing a metal container to which the present invention is applied, sealed with a metal cap, and FIGS. 2 and 3 illustrate a first embodiment of the method of the present invention. FIG. 2 is a diagram showing the state before heating the fitting part, FIG. 3 is a diagram showing the state after heating the fitting part, and FIG. 4 is a longitudinal sectional view of the method of the present invention. FIG. 7 is a longitudinal cross-sectional view for explaining the second embodiment of the present invention, and is a drawing showing a state before heating the fitting portion. 1... Metal container, 2... Upper can body (upper hollow body),
2a... Mouth part, 2b... Open end part, 3... Lower can body (lower hollow body), 3a... Bottom part, 3b... Diameter reduced part (open end part), 4... - Adhesive layer, 5... Peripheral joint part, 7... Fitting part, 11... Metal container assembly, 13.
...Placement plate (second member), 16... Sealing tool (first member), 26... Sealing tool, 27... Height regulating plate (first member). Patent applicant Akira Kishimoto

Claims (1)

[Claims] (1) The opening ends of the lower hollow body having a bottom and the upper hollow body having a mouth are fitted together via a heat-fusible adhesive layer to form a metal container assembly having a fitting part. After that, the adhesive layer is heated and melted by heating the fitting part to produce a metal container having a local joint part, the method comprising: first members facing each other arranged at regular intervals; The metal container assembly is inserted between the metal container assembly and the second member, and the fitting part is heated with the mouth part sealed, and the metal container assembly is heated due to the pressure of the internal gas expanded by heating. A method for manufacturing a metal container of a constant height having a circumferential joint, characterized in that axial sliding of the open end via a molten adhesive layer is restricted by a first member and a second member.