JPH0510213B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to a plastic can suitable as, for example, a food or drink container, and an apparatus that can be used to manufacture the same. It goes without saying that containers for food and beverages must be safe from a food hygiene perspective, but they also have various other characteristics depending on the purpose, such as water resistance, oil resistance, retort sterilization, self-supporting properties, and gas barrier properties. It is required to have the following physical properties. For example, metal cans have these physical properties, but recently the problem of empty can pollution has been brought up, and the transportation of cans from can manufacturing factories to cans with large empty volumes to filling factories. Inefficiency was also a problem. On the other hand, plastic is easy to mold,
Although metal cans are already being used as a variety of container materials, metal cans are still being used in the food and beverage container field, which requires them to have the various physical properties mentioned above, and is also subject to the additional restriction that they must be low cost. The current situation is that it has not been put into practical use. Conventionally, when attempting to manufacture the body of a plastic can using a material mainly made of plastic, the technology has not been developed due to problems with the physical properties of the plastic itself, especially problems associated with heat treatment. For example, the present inventors found that when the body cylinder has a structure having a content protection layer and a support layer outside the content protection layer, in order to solve the above problem, the content protection layer should have a homogeneous cylindrical part and It has been found that it must be formed into something that is not easily deformed. As a result of further consideration of this problem, the inventor found that
It was discovered that many of the causes of the deformation are due to heat shrinkage of plastics or gases mixed in, and they also found a technical means to solve the problem, thereby completing the present invention. That is, in the present invention, one side edge of a laminated film is folded back outward, this folded part is glued so as not to trap air bubbles, and the other side edge of the same laminated film is attached to the folded part to prevent air bubbles from being trapped. The present invention relates to a plastic can comprising a body member having a shape support layer applied to the outside of the cylinder on which a convex strip is formed by polymerization bonding without incorporating the plastic can, and an apparatus that can be used for manufacturing the same. The laminated film constituting the content protection layer can have various configurations depending on the purpose of the can, but when the plastic can of the present invention is used as a food and beverage container to replace a metal can, For the contacting innermost layer, polyolefin such as polyethylene, polypropylene, or ethylene propylene copolymer is suitable. The polyethylene is preferably high-density polyethylene in terms of resistance to retort treatment. The intermediate layer is preferably made of a material having gas barrier properties such as ethylene vinyl alcohol copolymer or vinylidene chloride, and aluminum foil is particularly suitable for the intermediate layer in order to ensure perfect gas barrier properties. A suitable plastic is laminated to the outermost layer to protect the intermediate layer, but unless there is a special purpose, the same polyolefin as the innermost layer may be used. Various other materials are laminated on the intermediate layer depending on the purpose of use, and an adhesive layer is provided between each layer as necessary. An appropriate adhesive is selected depending on the two layers to be adhered. For example, carboxylic acid grafted polypropylene, urethane adhesive, etc. are suitable for adhering the polyolefin layer and aluminum foil. The thickness of such a laminated film is determined in consideration of the thickness of the cylindrical body which is the body member of the plastic can of the present invention, and is usually suitably 250μ or less, particularly about 50 to 150μ. A cross section of an example of the laminated film 1 is shown in FIG.
This structure is for food use, and the innermost layer is a polypropylene layer A with a thickness of 70μ, and on top of that a layer B of carboxylic acid grafted polypropylene (trade name: Liocene, manufactured by Toyo Ink Co., Ltd.) with a thickness of 7μ. An aluminum foil C with a thickness of 9 μm and a urethane adhesive layer D with a thickness of 4.5 g/m ² are laminated in this order, and a polypropylene layer E with a thickness of 30 μm is arranged as the outermost layer. The laminated film 1 thus constructed has excellent physical properties as a container material for food and beverages having various physical properties such as water-based and oil-based, and can sufficiently withstand retort processing. One side edge 2 of the laminated film 1 is folded outward and adhered 3, and the other side edge 5 of the same laminated film 1 is overlapped and adhered to this folded surface 4, as shown in FIG. 2. . One side edge 2 of the laminated film 1 is folded back outward, and the folded part 2 is bonded without trapping air bubbles. The reason why the one side edge 2 is folded outward is to prevent the cut surface of the laminated film 1 from touching the contents of the can, thereby preventing the middle layer C,
This eliminates the influence of the adhesive layers B, D or the outermost layer E (although there is no problem in the example of FIG. 1) on the melt in the can. The side edge 2 to be folded back is the lower one of the overlapping side edges. The folding width l depends on the cylinder diameter, adhesive strength, required airtightness, etc., but is usually 2~
It is about 20mm. The folded portion 2 is bonded 3 without incorporating air bubbles. Bonding may be done using an adhesive, but since the same materials are facing each other, it is usually best to use heat welding. This adhesion eliminates the occurrence of unevenness on the cylinder 12 due to the lifting of the folded part 2, and also eliminates the trapping of air bubbles, so that when applying the molten plastic from the T die 29, air bubbles are prevented by the heat of the plastic. The heat expands and pushes up the unhardened plastic, creating surface protrusions that prevent the body member from becoming uneven. Eliminating these surface protrusions is important not only for aesthetic reasons, but also for easy and reliable attachment of the lid. Furthermore, by eliminating air pockets, uneven heating during retort processing is also prevented. The body member 12a was made in the presence of air bubbles, and the cosmetic properties and the fitability of the lid body 13 were tested. Even if a general paper label, plastic label, etc. were attached, it was impossible to hide the unevenness of the surface. In addition, although the lid 13 was attached to the body member 12 using a high-frequency heating device and an infrared line heater, which will be described later, the opening end 1 of the body member 12
Since the cover 10 is deformed according to the unevenness, the cover 13 cannot be pressure-bonded uniformly over the entire circumference.
Approximately 5% seal failure occurred. Although the unevenness caused by the surface protrusions is fatal in this way, by eliminating the trapped air bubbles, the body member 12a can be made uniform and smooth.
Direct printing and reliable sealing became possible. The other side edge 5 of the same laminated film is superimposed and adhered to this folded surface 4 without introducing air bubbles. It is the same as above that air bubbles are not introduced.
Adhesion is preferably by thermal welding. A tube 6 is formed by overlapping and adhering the side edges 2 and 5, and this tube 6 may be formed by spirally winding the laminated film 1, as shown in FIG. It may also be formed by so-called gassho pasting, in which both side edges 2 and 5 of the film 1 are rolled and brought together. The tube 6 formed in this way may be used as it is as the body member 12a, but a support layer may be further laminated on the outside of the tube 6 as a content protection layer. In that case, for example, if the tube 6 is left as it is, a convex strip 7 is formed by joining the side edges 2 and 5, so that the convex strip 7 is formed over the entire outer surface 8 of the laminated film other than the convex strip 7. It is preferable to attach an adhesive sheet 9 having a thickness approximately equal to the height of the convex strip 7 to make the surface flat. FIG. 4 shows a cross-sectional view of the state in which the adhesive sheet 9 is attached. The material of the adhesive sheet is appropriately selected depending on the intended use of the can, but in the illustrated example, polypropylene with a thickness of 200 μm is pasted with a urethane adhesive. In addition to the adhesive sheet 9, other materials may be laminated on the support layer on the outer surface of the tube 6 as appropriate. For example, by applying polyolefin 11a kneaded with an inorganic substance, it is possible to impart rigidity to the tube 6, increase load resistance, facilitate adhesion of the lid, and reduce changes in the volume of the can. The advantages of layering this inorganic mixture are not only these, but also the fact that it reduces the amount of calories burned, eliminates the flow of plastic melting during combustion, and allows waste cans to be burned in an upright position.
It also has the advantage of improving the heat transfer coefficient and allowing the contents of the can to be heated or cooled more quickly and uniformly. The inorganic substance is preferably powder of calcium carbonate, talc, mica, etc., and calcium carbonate and talc are particularly suitable. The amount of kneading is preferably such that the content of inorganic substances in the kneaded product is 20 to 90% by weight, particularly 40 to 70% by weight. In order to perform kneading uniformly and quickly, titanium-based coupling agents such as isopropyl triisostearoyl titanate, tetra-n
- It is advisable to add a coupling agent such as a silane coupling agent such as butoxysilicon or a zirconium coupling agent such as tetra-n-butoxyzirconium to the inorganic material in an amount of 0.1 to 10% by weight, preferably 0.5 to 3% by weight. . If necessary, a pigment such as titanium oxide may be further added to this kneaded material for the purpose of coloring. Next, various physical properties were determined using a kneaded product obtained by kneading 50% calcium carbonate or talc into polypropylene, and a cylindrical body 12 (however, without the layer 11b) constructed using this kneaded product as shown in FIG. The measured results are shown in the table below. (a) Kneaded product

[Table] * Polypropylene
(b) Cylindrical body (1) Compression test Sample and method: A cylinder with a diameter of 53 mm and a height of 130 mm was pressurized in the longitudinal direction of the cylinder at a speed of 10 mm/min using a compression testing machine. Result

[Table] (2) Retort treatment resistance Sample: Round can filled with 0.27 kg of water and fitted with a PP lid Square can filled with 0.31 kg of water and fitted with aluminum Retort conditions: Rotating retort sterilizer Temperature 125-130℃ , constant differential pressure 1.0Kg/cm ² , rotation speed 6rpm, F ₀ value 15

[Table] (3) Others By kneading charcoal or talc, the formability from a round tube to a square tube was improved. In order to increase the smoothness of the outer circumferential surface of the cylindrical body having such a structure and to give it gloss, if necessary, plastic is further applied smoothly. This smoothing treatment is particularly effective when the outermost layer is an inorganic-mixed plastic, since the surface will be rough. The thickness of the cylinder 12 configured in this way is
It is determined because the cans can stand up on their own and can be stacked, and is usually about 300 to 3000 μm, particularly about 500 to 1500 μm, which is often appropriate. An example of the structure of the cylindrical body is shown in FIG. 5, and an enlarged view thereof is shown in FIG. 6. As shown in the figure, the cylinder of this example has a 70μ polypropylene layer A, a 7μ carboxylic acid grafted polypropylene layer B, a 9μ aluminum foil C, a 4.5g/m ² urethane adhesive layer D, and a 30μ polypropylene layer from the inside. Laminated film 1 of content protection layer consisting of layer E, urethane adhesive layer F of 4.5 g/m ² , adhesive sheet 9 of 200 μm polypropylene, and approximately 600 μm film made by kneading polypropylene and calcium carbonate at a ratio of 1:1. The supporting layer consists of a deposited plastic layer 11a of 100 .mu.m thick and a coating layer 11b of a 10-20 .mu.m polypropylene block copolymer. The cylindrical body 12 is cut into regular intervals, and the surface of the cylindrical body 12 is usually printed or affixed with a label for use as a body member of a can. In this case, if the surface has been smoothed by applying the plastic, it is possible to print on the surface after, for example, corona treatment or flame treatment. The lid 13 to be attached to the body member 12a using such a cylinder 12 is shown in FIG. 7 or 9, for example.
The one shown in the figure may be used. The lid 13 shown in FIGS. 7 and 8 is for a round can, and the periphery has
A peripheral wall 14 is formed of an inner wall 111, a top portion 15, and an outer wall 113, and is fitted into and bonded to the open end 110 of the body member 12a. FIG. 8 is a sectional view taken along the line A--A in FIG. 7. The back surface of the circumferential wall 14 is fitted into the open end 110 of the body member, and in the embodiment, the inner wall 111 is bonded to the inner wall of the open end 110. In order to complete this bond and provide sufficient adhesive strength, the height of the inner wall was increased to 4.
It is better to take more than mm. The lid 13 shown in FIG. 9 is for a square can, and has four notches 20 at each corner of the outer wall of the circumferential wall 14.
It has basically the same structure as the lid shown in Figure 7, except that it is provided with a. Each of these lids 13 is formed by laminating the laminated film 1 used for the tube 6 on the lower surface of a polypropylene lid body formed by injection molding. A first example of a round plastic can of the present invention is shown below.
In addition to FIG. 0, FIG. 11 shows a perspective view of an example of a square can. Next, an example of an apparatus for manufacturing plastic cans according to the present invention will be explained. FIG. 12 is an explanatory diagram illustrating an apparatus for manufacturing the cylindrical body 12. 21 is a roll of the laminated film 1, and the laminated film 1 is unwound from this roll 21, one edge 2 is folded back by the edge folding device 22, passes under the mandrel 27, and reaches the pressure roll 26. .
On the other hand, the adhesive sheet 9 is fed out from a roll 23, coated with adhesive on one side by a gluing device 24, dried in a hot air dryer 25, and then adhered to the laminated film 1 by a pressure roll 26. The laminated sheet 10 formed by pasting the adhesive sheet 9 on the laminated film 1 is wound around a mandrel 27 and air heater 28
The side edges 2 and 5 that overlap with each other are glued together, and the T die 2
9, a molten plastic 60 is applied. Next, the surface is leveled with a leveling belt 30, the molten plastic is applied smoothly to the surface with a doctor knife 31, and the plastic is cut into a certain size with a circular saw blade 74. A perspective view of the edge folding device 22 is shown in FIG. This edge folding device 22 consists of two width regulating plates 33, 33 and rods 34, 34, 34 which adjust the distance between the width regulating plates 33, 33 and keep it constant. Each rod slidably passes through the width regulating plate, and screws 35, 3
It is fixed by tightening 5, . . . , 35. One side edge 2 of the laminated film 1 is continuously folded to a predetermined width simply by passing the edge folding device 22. The edge folding device 22 is not limited to this embodiment; in short, it may be arranged at a position where an appropriate stress is applied to the side where the member that regulates the width is folded back.
Alternatively, the rod may be brought into contact with one side edge 2 of the laminated film 1 and folded back. A perspective view of the periphery of the pressure roll 26 is shown in FIG. The pressure roll 26 presses the folded part 2 of the laminated film 1 to adhere it without taking in air bubbles, and also presses the adhesive sheet 9 to the laminated film 1 to adhere it without taking in air bubbles.
It consists of a pair of rolls, an upper roll 26a and a lower roll 26b. The pressure roll 26 includes a nip roll in which a thick rubber body 26d is adhered to a metal roll 26c as an upper roll 26a, and the upper and lower positions thereof can be freely adjusted. Rubber body 26
d increases the pressure contact force between the rolls 26a and 26b due to its elasticity, and makes the air bubbles and adhesion between the laminated film 1 and its folded portion 2 to be joined and the laminated film 1 and the adhesive sheet 9 more perfect.
This rubber body 26d must be heat resistant, and silicone rubber, for example, is suitable. The upper roll 26a is provided with a vertical position adjustment mechanism (not shown) that adjusts the pressure contact force between the rolls 26a and 26b to an appropriate level. The lower roll 26b is made of a metal roll and has a drive mechanism (not shown) and a cooling water pipe 26e. The drive mechanism is capable of changing speed, and is adjusted so that the traveling speed of the original fabrics 1 and 9 matches the traveling speed of the laminated sheet 10 on the mandrel 27. The water pipe 26e for temperature control water (for example, 40 to 50°C is suitable) cools the lower roll 26b, removes the heat from the adhesive sheet 9 and the side edge 2 of the laminated film 1, and cools the raw fabric 1, 9
It also prevents the laminated sheet 10 from meandering, twisting, etc. In front of the adhesive sheet supply side of the pressure bonding roll 26, there are two regulating rings 36 for regulating the position of the adhesive sheet 9.
36 is inserted and disposed through the rod body 37. The regulating rings 36, 36 keep the adhesive sheet 9 at a predetermined position on the laminated film 1, that is, on both side edges 2,
This screw is provided because it is necessary to overlap the surface between the convex strips 7 formed by joining the rods 37 accurately, and the screw 3 is slid on the rod body 37 and placed in an appropriate position.
8,38. Further, a cartridge air heater 39, which is a type of local heating heater, is disposed in front of the laminated film folded portion 2 on the lower roll 26b. A side view of the cartridge heater is shown in FIG. This heater 39 heats and welds the folded portion 2, and a heating wire 41 is placed inside the glass tube 40.
is provided, and a socket 42 at the base of the glass tube is provided.
An air supply pipe 43 is connected to the tube, and the air heated by the heating wire 41 is sent to the nozzle section 4 at the tip of the glass tube.
Make it blow out from 4. In this pressure roll 26b, one side edge 2
The folded laminated film 1 enters from the lower right side in FIG. 14, is hung on the lower roll 26b, and exits to the right. Then, the folded portion 2 is heated by hot air blown from the cartridge heater 39 on the lower roll 26b, and the upper and lower rolls 26b are heated.
When passing through the contact portions a and 26b, the folded portion 2 is pressed and welded. On the other hand, the adhesive sheet 9 enters from the left side of the drawing, and is positioned by passing between the two regulating rings 36, 36 when passing through the rod 37. 26b, it is pressed into a predetermined position on the laminated film 1. As described above, this pressure roll 26 simultaneously performs the pressure bonding of the two parts, but it is also possible to use two pairs of pressure rolls to perform the pressure bonding separately. The original fabric passed through the pressure roll 26 is transferred to the mandrel 2
It is wound around 7. The first cross-sectional view of the mandrel 27
It is shown in Figure 6. This mandrel 27 has an aluminum circular tube on the outside and is closed at both ends. The entire circumferential surface is made of porous hard aluminum oxide, and the porous structure is impregnated with tetrafluoride resin (trade name: Teflon) to facilitate the sliding of the wound raw material. A small step 45 is provided in the middle of the mandrel 27, and the distal end thereof forms a small diameter portion 46 that is smaller in diameter than the proximal end. A cover plate 47 is bolted to the base end of the mandrel, and the cover plate 47 includes a water passage pipe 48 serving as a liquid passage for passing liquid through the gap between the surface of the small diameter portion 46 and the tube 6 of the laminated film 1, and a water passage pipe 48 that serves as a passage for liquid to pass through the gap between the surface of the small diameter portion 46 and the tube 6 of the laminated film 1, and the mandrel. A water pipe 49 for cooling the inside and its drain pipe 50 are welded together. A discharge port 51 of the water pipe 48 is provided on the peripheral wall surface at a slightly more distal end than the stepped portion 45, and a guiding groove 52 spirals from the discharge port 51 on the peripheral wall surface over about 1/3 of the total length of the small diameter portion. It is engraved.
As shown in FIG. 17, this small diameter portion is formed by providing a gap between the laminated sheet cylinder 56 and the mandrel peripheral wall surface and allowing water to flow through this gap.
6 is cooled to prevent softening of the laminated sheet cylinder 56 and expansion wrinkles of the aluminum, and the floating by water helps propel the laminated sheet cylinder 56. The guide grooves 52 are provided to allow water to flow uniformly through the gaps and to facilitate applying floating force to the laminated sheet cylinder 56. As shown in FIG. 17, this mandrel 27 is fixed substantially horizontally at its base end by being held between two pressure bonding plates 53 and 54. Reference numeral 55 is a handle for moving the upper pressure bonding plate 53 up and down. The first perspective view shows a state in which the laminated sheet 10 formed by pressing the adhesive sheet 9 onto the laminated film 1 with the pressing roll 26 is wound on the mandrel 27.
Shown in Figure 8. As shown in the figure, the laminated sheet 10 is wound with the side edges 5 superimposed on the folded portions 2 of the already wound laminated sheet 10. At this time, the side edge portion 5 is connected to the cartridge air heater 2, which is the same as that used in the pressure roll 26 immediately before winding.
8, and during winding, the overlapping portions are fused due to the tension between the pressure roll 26 and the mandrel 27 without trapping air bubbles. The laminated sheet cylinder 56 formed by being wound on the mandrel 27 rotates on the mandrel 27 fixed by a delivery belt 57 wound around its outer periphery, and is sent out from the mandrel 27. A perspective view of this delivery belt mechanism is shown in FIG. The delivery belt 57 is spirally wound once around the laminated sheet cylinder 56, and is passed around a pair of rotating rolls 58a and 58b disposed on both sides of the mandrel 27. And both rotating rolls 5
8a and 58b are driven and rotated by a motor (not shown), and the laminated sheet cylinder 56 is rotated and advanced by the rotational force thereof. The laminated sheet cylinder 56 to which the overlapping portion is welded is the first
As shown in FIG. 7, molten plastic 60 kneaded with an inorganic substance is then applied over the entire outer peripheral surface using a T-die 29. As the inorganic material kneading device (not shown), a conventional kneading device may be used, but the moisture content of the kneaded pellets is controlled to be less than 300 ppm, preferably less than 150 ppm. When the amount exceeds 300 ppm, the melted plastic 60 that becomes the deposited plastic layer 11a begins to break. This molten plastic 60 is preferably deposited on the small diameter portion 46 of the mandrel 27, so that the inner surface of the laminated sheet cylinder 56 is cooled by the cooling water 59 discharged from the discharge port 51, and the laminated sheet cylinder 56 is laminated. Softening of the sheet 56 is prevented. The extrusion position of the molten plastic 60 is the sixth
As shown in the figure, it is preferable that the inner edge portion 60a be located at a position slightly shifted to the right in the drawing from the convex band upper part 7. In this way, the edge part 6 of the extruded resin
By bringing 0a close to the convex strip 7, a spiral convex portion 61 on the surface of the adhered plastic 11a is formed.
can be easily leveled by a leveling belt 30, which will be described later. On the other hand, the joint 60b between the extruded resins
When placed on the convex strip 7, the laminated film 1
If aluminum foil is used for this purpose, the convex band-like portion is likely to be allowed to cool, resulting in poor bonding between the adhered plastics 11a at the bonding portion 60b. As described above, since the spiral convex portion 61 exists on the surface of the cylinder 12 to which the molten plastic 60 is adhered, the surface is smoothed by a surface leveling device before the adhered plastic layer 11a is completely solidified. It is better to treat it. This spiral convex portion 61 tends to appear in the convex strip portion 7 formed by joining the side edges 2 and 5, and also tends to appear at the connection portion of each winding of the adhered plastic layer 11a, so as shown in FIG. It is best to align the two and level the area as shown in the figure.
The surface leveling device also has the function of leveling the spiral convex portion 61 and reliably bonding the joint portion 60b without bubbles. A plan view of an example of a surface leveling device is shown in FIG. In this device, the leveling belt 30 is wound three times around the spiral convex portion 61, and the leveling belt 30 is suspended between a pair of rolls 62a and 62b provided at the lower portions of both sides of the mandrel 27. The leveling belt 30 runs due to the drive of the spiral convex portion 6.
It is designed to equalize 1. A cross-sectional view of the leveling belt 30 in contact with the cylindrical body 12 is shown in FIG. As shown in the figure, the leveling belt 30
The entry-side lower surface 63 of the surface to be leveled is slightly raised to gradually press against the spiral convex portion 61. This is because if a simple flat belt is used as the leveling belt 30, the edges of the belt will create a recess on the surface.
3, it was possible to level out the spiral convex portion 61 and flatten the surface of the adhered plastic layer 11a, and at the same time, it was possible to reliably join the joint portion 60b. The inclination angle (θ) of the lower surface 63 on the approach side is 2 to 10°
The length of the lower surface 63 on the entry side is suitably about 1/5 of the total width of the leveling belt 30. Further, the position of the leveling belt 30 is such that, as shown in FIG. The width should be about 1/2 to 3/4, that is, the portion of the belt 30b on the soft side that has been wound later is about 1/2 to 1/4 of the total width of the leveling belt 30. Good. If the number of turns on the 30b side of the leveling belt 30 is increased, the cylindrical body 12 will be deformed by the pressing force of the leveling belt 30. Incidentally, the surface of the leveling belt 30 is silicon-treated in order to smoothly perform the leveling process. The surface of the cylindrical body that has been roughly finished in this way is coated with molten plastic 65 to smooth and finish it. An example of this surface smoothing device is shown in FIGS. 22 and 23. In this device, a doctor knife 31 is brought into contact with the lower part of the cylinder 12, and a die 6 is placed on this knife 31.
A molten plastic 65 is supplied from 4, and the surface of the cylinder 12 is coated smoothly with the molten plastic 65 using an elastic blade 66 of a doctor knife 31. The elastic blade 66 is held on a blade holding plate 68 pivoted to a shaft rod 67 by being pressed from above by a blade holding plate 69, and is held at the tips of levers 70, 70 extending rearward from both side edges of the blade holding plate 68. The balance weight 71 suspended from the cylinder body 12 is pressed against the cylinder body 12 with a uniform pressing force. If left as it was, the doctor knife 31 would bounce due to the vibrations of the mandrel 27, causing countless vertical stripes on the surface of the cylinder 12, which are uneven coating. Shock material 13
1 or an air cylinder 132 was provided as shown in FIG. This blade holding plate 68 is provided with an embedded heater 72 to prevent the molten plastic 65 on the elastic blade 66 from cooling and solidifying. By applying the plastic using the elastic blade 66, the surface of the cylinder 12 becomes completely smooth and glossy, and printing can be directly performed on this surface. The cylindrical body 12 subjected to this surface smoothing treatment is the 24th cylinder.
As shown in the figure, when the mandrel 27 advances beyond the tip and hits the hanging plate switch 73, this switch 73 is activated and the circular saw blade 74 rotates and descends, cutting the cylinder 12 to a predetermined length. do. The cut cylinder 12 rolls down on the slope plate 75 and is transferred to the conveyor 76 to the next process. When this cylindrical body 12 is used for the body of a square can, it is formed into a square tube using a square tube forming apparatus. FIG. 25 shows an outline of an example of a square tube forming apparatus. That is, the circular cylindrical body 12 (the illustrated cylindrical body 12 is formed into a square cylinder) is transferred from the conveyor 76 to the next conveyor 7.
7, the sheet travels along the conveyor 77 in the cylinder length direction, passes through four guide rollers 78 arranged in a frame shape, and is heated at the bent portion by an infrared line heater 79. Subsequently, the surface between the bent portions is reversely deformed into a concave arc shape by a wheel-shaped roller 80, and a rectangular tube forming mandrel 81 mounted on a turret 82 stretches it from the inside to form a rectangular tube. As shown in FIG. 26, the infrared line heater 7
9, 79, 79, 79 are arranged at the four corners corresponding to the bent portions, and each has a concave reflecting mirror 83, 83, 83, 83 focused on the bent portion. Further, auxiliary heaters 84, 84, 84, 84 are arranged between the infrared line heaters 79, . The auxiliary heaters 84, . . . , 84 may be unnecessary depending on the material, thickness, etc. of the cylindrical body 12. Using this method, you can freely change the size and aspect ratio, change the shape of the mandrel,
By increasing or decreasing the number of wheel-shaped rollers 80, any polygonal cylinder can be easily manufactured.
The line speed can be easily changed by changing the length of the infrared line heater 79 or by adjusting the voltage. After the bent portions are heated and softened, each surface between the bent portions is reversely deformed into a concave arc shape using wheel-shaped rollers 80, 80, 80, 80. Wheel type roller 80
A perspective view of the peripheral portion is shown in FIG. 27. This wheel-shaped roller 80 is a metal disk whose peripheral edge is wrapped with rubber, and is driven by the rotation of a small roller 85 that comes into contact with this peripheral edge. Each wheel type roller 8
0, . . . , 80 are fixed to a frame 87 via screw rods 86. A cross-sectional view of the cylinder 12 in a state where it is being deformed by the wheel-shaped roller 80 is shown in FIG. The cylindrical body 12 that has been deformed by the wheel-shaped rollers 80 is inserted into each cylindrical forming mandrel 81.
FIG. 29 shows a longitudinal cross-sectional view of each tube-forming mandrel 81, and FIG. 30 shows a perspective view of the periphery of its head. Each of the cylindrical mandrels 81 is a rod-shaped body with a generally rectangular cross section, and the head 88 is narrowed so that it can be easily inserted into the cylindrical body 12. Back rod part 89 in the direction
and a movable rod piece 90. A long groove 91 is cut in the longitudinal direction of the back rod portion 89 on the side that meets the movable rod piece 90, and an air tube 92 is fitted into this long groove 91. Movable rod piece 90
is screwed to the back rod part 89 so as to be slidable in the lateral direction. The screws 93 are arranged in pairs in the longitudinal direction at several locations, and are screwed onto the movable rod piece 90 from the back rod portion 81 side. A spring 95 is disposed around the long neck portion 94, and the movable rod piece 90 is extended outward and returned to its original position in response to the expansion and contraction of the air tube 92. There is. As shown in FIG. 31, five square tube forming mandrels 81 are fixed to a turret 82 in a circular shape. A large rotary disk 96 provided on the front surface of the turret 82 rotates intermittently, and a shaft 97 for fixing the rectangular cylinder forming mandrel 81 is configured to move forward and backward, and is arranged at equal intervals on the rotary disk 96. . The cylindrical body 12 is moved forward by the drive of the wheel-shaped rollers 80, . While the bent portion of the cylinder body 12 is still in a softened state, pressurized air is blown into the air tube 92 and the movable rod piece 90
is stretched out, and the cylinder body 12 is stretched and formed into a square cylinder. 98 is a block that presses the side surface of the rectangular tube forming mandrel 81 during expansion, and 99 is a support roller for the rectangular tube forming mandrel 81. The rectangular tube forming mandrel 81 expands, and the shaft 97 retreats while holding the tube, and the rotary disk 96 rotates by one-fifth.
The shaft rotates and fixes the next rectangular cylinder forming mandrel 81, and moves forward to receive the next cylinder 12. The square tube forming mandrel 81 rotated four-fifths in this way.
The movable rod piece 90 is pulled down to the stored state, and during this time the cooled cylinder 12 is pulled out from the mandrel 81. The square tube thus manufactured or the round tube that has not been subjected to the square tube forming process is cut into a constant length so as to have a predetermined can length. A perspective view of an example of a cutting device is shown in Fig. 32.
As shown in the figure. This device includes a receiving shaft 100 as a cylindrical support member, a shaft drive mechanism 101, a circular blade 102, and a receiving shaft 100 with a constant pressure.
It consists of an air cylinder 103 that presses against the 00. The surface of the receiving shaft 100 is coated with plastic 104 to protect the circular blade 102, and one end is removably attached to a drive shaft 105 by a claw member (not shown). The other end of the receiving shaft 100 is supported by a shaft end support plate 106. This shaft end support plate 106 is designed to be able to rotate approximately 90 degrees, and after receiving the cylinder 12 (not shown) and being inserted into the shaft 100, it is rotated to support the shaft end. On one side of the circular blade 102,
As shown in FIG. 33, a disc-shaped plastic guide 107 with a diameter slightly smaller than the blade diameter is attached to the circular blade 102.
The circular blade 102 is attached concentrically with the cylindrical body to prevent the circular blade 102 from cutting beyond the cylindrical body more than necessary. This circular blade 102 has a number of arms 109, 109, which are rotatably supported at the lower end by a shaft rod 108 and arranged in parallel.
..., 109 are rotatably provided at each tip. And each circular blade 102, 102,..., 10
2 is pressed against the receiving shaft 100 with a constant pressure by the damper action of air cylinders 103, 103, .
2 is cut at regular intervals. After cutting is completed, the shaft end support plate 106 is rotated 90 degrees and the cylinder is removed from the receiving shaft 100. By replacing the receiving shaft 100, this device can quickly cut round and square tubes, and the size of the tube body 12 can be changed quickly. Also, the blade has a guide 1
Attach 07 and attach this blade to plastic shaft 1.
In this method of cutting by pressing against the plastic shaft 100, no force is applied to the circular blade 102 even when cutting square tubes, so the life of the blade is extended, and unlike conventional push-cutting, the blade can penetrate up to the plastic shaft 100. Therefore, the cut surface is clean and can be cut perfectly. In addition, the blade edge is not exposed more than necessary by the guide 107, which is preferable from a safety standpoint. As shown in FIG. 34, the lid 13 is attached to the open end 110 of the body member 12a, which is formed by cutting the cylindrical body 12 into a predetermined length. It is held down with a fitting block 112 and heated with a high frequency heating device. The aluminum foil of the laminated film 1 (see FIG. 8) is heated by this high-frequency heating, and the surrounding area thereof is melted. Then, by pressing the crimping block 114 against the outer wall 113 of the circumferential wall 14, welding occurs between the inner wall 111 of the circumferential wall 14, where the laminated film 1 is in contact with each other, and the inner circumferential surface of the opening end. be done. Crimping block 114
is divided as shown in FIG. 35, and each can be moved forward and backward by a cylinder 115. Each crimp block 114, 114, . . . 114 is made of a non-metallic material so as not to be affected by high frequencies. 116 is a high frequency coil, inside of which cooling water flows. After welding the inner wall 111 side of the lid body 13, the third
The outer wall 113 side is welded using the apparatus shown in FIG. This device includes a chain belt conveyor 117 that transports a body member 12a on which a lid 13 is attached, and a lid 13 whose outer wall 113 attached to the body member 12a is in an expanded state.
An infrared line heater 118 heats the inner surface of the outer wall 113 and the outer surface of the open end of the body member 12a.
A chain conveyor 120 is provided above and parallel to the chain band conveyor 117 and has a row of pressers 119 for pressing the lid 13, and a guide bar 121 for operating the pressers 119. As shown in FIG. 37, the infrared line heater 118 focuses on the outer wall 1 of the lid body 13 in the expanded state.
13 and the outer surface of the open end of the body member.
There are 2 pairs on each side of 7, totaling 4 units. The chain conveyor 120 has two parts stretched in parallel.
It consists of book chains 123, 123, and between these chains 123, 123 there are many base plates 124, 12.
4, . A perspective view of the presser 119 is shown in FIG. Presser 11
Reference numeral 9 is a substantially rectangular parallelepiped whose outer shape matches that of the cylindrical portion 12, and a convex circumferential strip 125 is provided on the top surface of the drawing to fit onto the inner wall 111 of the lid body 13, and a presser piece 1 is provided on both sides.
26, 126 are rotatably pinned.
These presser pieces 126, 126 are attached to the outer wall 1 of the lid body 13.
A pressing part 127 that comes into contact with the lid body 13 has a shape that matches the outer wall 113, and by pushing up a lever 128 that protrudes outwardly, the outer wall 113 of the lid body 13 is pressed against the body member 12a. In this device, the body member 12a to which the lid 13 is attached is attached to the chain band conveyor 11 from the right side in FIG.
7 and carried in, and the inner wall 111 of the lid 13 is fitted into the convex circumferential strip 125 of the presser 119 at the right end of the chain conveyor 120. Then, proceeding further to the left on the chain band, the infrared line heater 118,
118, 118, 118, and then the joint is heated by the cartridge air heater 133, and as shown in FIG. 128, 128 are gradually pushed down, and the outer wall 113 of the lid body 13 is pressed against the body member 12a. When passing the left end of the guide bar 121, the presser pieces 126, 12 are moved by the spring 129 of the presser.
6 is lifted up, and the body member 12 is sealed to the lid 13 by the baffle bar 130 at the left end of the chain belt conveyor.
a is dropped. The part that is sealed with this device is the lid 1.
Since there are only two sides of No. 3, one more similar device is arranged in series and the remaining sides are then sealed. In addition, in this apparatus, a local heating air heater such as a cartridge air heater may be added as necessary, and the infrared line heater 118 may be omitted. Figures 34 to 39 show square cans,
In the case of a round can, a lid is attached, for example, by the method shown in FIGS. 40-41. FIG. 40 is an explanatory diagram showing how to attach the lid 13, and FIG. 41 is a perspective view of the main parts. It consists of a fitting block 112 that presses the circumferential wall portion 14 from the inside, a cartridge air heater 135, a pressing roller 136, and a turntable 137. The high frequency coil 116 is connected to the laminated film 1 and the lid 13 that constitute the content protection layer of the body member 12a.
The inner wall 111 of the lid body 13 is heated by heating the aluminum foil of the laminated film 1 attached to the inner surface side of the lid body 13.
is welded to the inner circumferential wall of the open end 110 of the body member 12a, and cooling water flows inside.
The fitting type block 112 is loosely inserted into the high-frequency coil 116, and the enlarged diameter portion at the lower end is fitted into the blood-shaped concave top surface of the lid 13 to hold the lid 13 together with the body member 12a, as shown in the figure. It is driven by external power and rotates slowly. The lower surface of this fitting block 112 is cut into a dish shape. The cartridge air heater 135 heats and fuses the inner surface of the outer wall 113 of the lid 13 in the expanded state and the outer surface of the open end 110 of the body member 12a.
It is configured to be able to take either a vertical state or an approximately 30° inclined state with the socket portion 138 as an axis. The pressing roller 136 presses the outer lid 113 of the lid body 13 against the body member 12a, and is made of plastic. This roller 136 is rotatable, and the entire roller 136 is designed to be movable in the lateral direction.
The turntable 137 is provided with a protrusion 139 in the center into which the lower open end 110' of the body member 12a or the top surface of the lid recessed in a dish shape is fitted, and is configured to be freely rotatable and vertically movable. . To attach the lid 13 using this device, first, fit the lower end of the body member 12a into the protrusion 139 of the turntable 137, raise the turntable 137, and fit the top surface of the lid 13 into the mold. Fit into block 112. Subsequently, while rotating the fitting block 112, the cartridge air heater 135 is tilted to heat the inner surface of the outer wall 113 of the lid 13 and the outer surface of the open end 110 of the body member 12a. When the heated portion is properly melted, the cartridge air heater 135 is returned to the vertical position to stop heating, and the pressing roller 136 is moved laterally to move the outer wall 113 of the lid body to the body member 12a.
Press it against the open end 110 of and weld it. At the same time as this pressing roller 136, the high frequency coil 11
A high frequency wave is oscillated from 6 to heat and weld the inner wall of the lid. When the welding is completed, the pressing roller 136 is released from the lid 13 and returned to its original position, the turntable 134 is lowered, and the body member 12a to which the lid 13 is attached is removed. After filling the contents, the lid body 1 is attached to the other end of the body member 12a.
Attach 3 in the same way. By adopting this type of sealing system, the sealing part is formed into two stages to ensure a complete seal and prevent troubles due to sealing errors. Although the content of the present invention has been described above with a focus on Examples, the present invention is not limited to these Examples. The type of laminated material can be applied immediately when the laminated material does not come into contact with the contents of the can and the influence of the laminated material on the contents of the can is eliminated. In addition, in the embodiment, the spaces between the convex strips 7 were filled with the adhesive sheet 9, but if the body surface can have unevenness, this adhesive sheet 9 may not be used unless there are other problems such as strength. It's okay. In addition, the adhesive
This adhesive is used in cases where it is difficult to weld as is, or where it is difficult to weld because the entire body is deformed by heating, but this adhesive is suitable for the construction of the body member and the equipment used to manufacture the body member. It goes without saying that it can be used as appropriate.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an example of a laminated film.
FIG. 2 is a sectional view showing the adhesion state of the side edges of the laminated film, and FIG. 3 is a perspective view thereof. Fourth
The figure is a cross-sectional view of a state in which an adhesive sheet is further laminated, and Fig. 5 shows a cylindrical body completed by laminating an inorganic kneading layer (adhered plastic layer) and a smoothing layer (plastic coating layer) thereon. FIG. FIG. 6 is an enlarged sectional view of this cylinder. FIG. 7 is a plan view of an example of a lid for a round can, and FIG. 8 is a cross-sectional view taken along the line A--A. FIG. 9 is a plan view of an example of a lid for a square can. FIG. 10 is a perspective view of an example of a round can of the present invention, and FIG. 11 is a perspective view of an example of a square can. FIG. 12 is an explanatory diagram of an example of an apparatus for manufacturing a cylinder. FIG. 13 is a perspective view showing an example of an edge folding device for folding one side edge of a laminated film, and FIG. 14 is a perspective view of the area around the pressure roll. FIG. 15 is a side view of the cartridge air heater (air heater for local heating).
FIG. 16 is a sectional view with a part of the mandrel omitted, and FIG. 17 is a partially sectional view showing the installation state of the mandrel and the winding state of the laminated sheet. FIG. 18 is a perspective view showing the state in which the tube is wound, and FIG. 19 is a perspective view of the delivery belt portion that advances the wound tube. FIG. 20 is a plan view of an example of the surface leveling device, and the 21st receiver is a sectional view of the leveling belt in contact with the cylindrical body. FIG. 22 is a perspective view of an example of a surface smoothing device, and FIG. 23A is a side sectional view. FIG. 23B shows an example in which an air cylinder is used instead of silicone rubber. FIG. 24 is a perspective view of an example of a cutting device for roughly cutting the formed cylindrical body. FIG. 25 is an explanatory view of an example of a rectangular cylinder forming apparatus for forming a round cylinder into a rectangular cylinder, and FIG. 26 is an explanatory view showing an outline of the heating section thereof. FIG. 27 is a perspective view of an example of a device that reversely deforms the convex arc-shaped curved surface between the bent portions into a concave arc shape after exiting the heating section, and FIG. 28 is a sectional view showing the deformed state. FIG. 29 is a longitudinal sectional view of an example of a rectangular tube forming mandrel for forming a rectangular tube by pulling a tube from the inside, and FIG. 30 is a perspective view of the vicinity of the head thereof. FIG. 31 is a perspective view showing the state in which this rectangular cylinder forming mandrel is held by a starlet. FIG. 32 is a perspective view of an example of a cutting device for cutting a cylindrical body into a certain length;
Figure 3 is a side view of the circular blade. FIG. 34 is an explanatory side view of an example of a high-frequency heating device for sealing the lid of a square can, and FIG. 35 is a plan view of the main parts thereof. FIG. 36 is an explanatory diagram of an example of an apparatus for heating and welding a lid, and FIG. 37 is an explanatory diagram showing a heating state. FIG. 38 is a perspective view of the presser, and FIG. 39 is a side view showing the operating state of the presser. FIG. 40 is an explanatory view of an example of a device for attaching a lid to a round can, and FIG. 41 is a perspective view of the main parts. 1... Laminated film (content protection layer), 2...
One side edge (folded part), 4...Folded surface, 5...
Other side edge, 6...Cylinder, 7...Convex strip, 9...Adhesive sheet, 10...Laminated sheet, 11a...Inorganic kneading layer (adhered plastic layer), 11b...Coating layer, 12 ... Cylindrical body, 12a ... Body member, 13 ... Lid body, 14 ... Circumferential bank part, 15 ... Top part, 26 ... Nip roll (crimping roll), 27
...Mandrel, 29...T dice (dice),
30... leveling belt, 31... doctor knife,
39... Cartridge air heater (air heater for local heating), 46... Small diameter portion, 48... Water passage pipe (liquid passage), 51... Discharge port, 52... Spiral groove (guiding groove), 63... ... lower surface on the entrance side, 66 ... elastic blade, 79 ... infrared line heater, 81 ...
Rectangular tube forming mandrel, 83...Concave reflecting mirror, 10
2...Circular blade, 110...Opening end, 111...Inner wall, 113...Outer wall, 114...Crimping block (pressing member), 118...Infrared line heater, 122...Concave reflecting mirror, 131... ...Modifying material (mandrel vibration absorption mechanism), 132...Air cylinder (mandrel vibration absorption mechanism).

Claims (1)

[Scope of Claims] 1. One side edge of the laminated film is folded back outward, this folded part is glued so as not to introduce air bubbles, and then the other side edge of the same laminated film is attached to the folded part. The body member is provided with a shape support layer made by smoothing molten resin extruded from a T-die and adhered to the outside of the cylinder in which the convex strips are formed by polymerization bonding without incorporating air bubbles. A plastic can characterized by: 2. The plastic can according to claim 1, wherein the bonding of the folded portion of one side edge of the laminated film and the bonding of the other side edge to the folded portion are thermal welding. 3. A plastic layer equal to the height of the convex strips is applied over the entire surface of the laminated film except for the convex strips formed by both side edges of the laminated film, and this plastic layer is 3. A plastic can according to claim 1, wherein a shape support layer is applied to cover the convex strips. 4. The plastic can according to claim 1, 2 or 3, wherein the shape support layer has at least one plastic layer kneaded with an inorganic substance. 5. The plastic can according to claim 1, 2, 3, or 4, wherein the laminated film includes an aluminum foil and polyolefin layers laminated on both sides of the aluminum foil. 6 At the open end of the body member, the inner wall, the top, the outer wall,
Claims 1, 2, 3, 4, or 5, wherein the lid body including the peripheral bank is joined such that the inner wall of the peripheral bank becomes the inner wall of the open end of the body member. The plastic can described in paragraph 5. 7 One side edge of the laminated film is folded back outward, this folded part is glued so as not to take in air bubbles, and the other side edge of the same laminated film is placed on the folded part so as not to take in air bubbles. In an apparatus for manufacturing a plastic can having a body member in which a shape support layer is adhered to the outside of a cylinder which is polymerized and bonded to form a convex strip, the folded portion of the laminated film is heated. A plastic can manufacturing device comprising an air heater for local heating and a pressure roll for pressure-bonding the heated folded portion. 8 One side edge of the laminated film is folded back outward, this folded part is glued so as not to take in air bubbles, and the other side edge of the same laminated film is attached to the folded part so as not to take in air bubbles. In an apparatus for manufacturing a plastic can having a body member in which a shape support layer is adhered to the outside of a cylinder on which convex strips are formed by polymerization bonding, A mechanism for overlapping a plastic layer with a thickness approximately equal to the height of the convex strips over the entire outer surface of the laminated film except for the convex strips formed by the process, and a crimping mechanism for crimping the overlapping plastic layers to the laminated film. A plastic can manufacturing device characterized by having a roll. 9. The pressure roll has a surface made of a rigid material, and
9. A plastic can manufacturing apparatus according to claim 8, comprising a roll made of a heat-resistant elastic material. 10. The plastic can manufacturing apparatus according to claim 9, wherein the press roll is capable of simultaneously press-bonding the folded portion. 11 A state where one side edge of the laminated film is folded back outward, this folded part is glued so as not to take in air bubbles, and the other side edge of the same laminated film is attached to the folded part so as not to take in air bubbles. The pipe is polymerized and bonded to form a cylinder on which a convex strip is formed, and has a slightly smaller diameter part on the tip side, and a passage for passing cooling liquid between the cylinder and the small diameter part. A mandrel characterized by having a liquid path. 12. The mandrel according to claim 11, wherein a guiding groove is provided in the circumferential surface of the small diameter portion in a spiral manner from the discharge port of the liquid passage. 13 One side edge of the laminated film is folded back outward, this folded part is glued so as not to take in air bubbles, and the other side edge of the same laminated film is attached to the folded part so as not to take in air bubbles. In an apparatus for manufacturing a plastic can having a body member on which a shape support layer is adhered to the outside of a cylinder which is polymerized and bonded to form a convex strip, the entire outside of the cylinder is coated with molten plastic. The present invention is characterized by having a die for attaching the plastic, and a surface leveling device for leveling out the spiral convexity existing on the surface of the plastic on the mandrel before the plastic coated with the die is completely solidified. Plastic can manufacturing equipment. 14 Claims in which the surface leveling device comprises a leveling belt spirally wound an appropriate number of times on a spiral convex portion, and a drive mechanism that runs this leveling belt under an appropriate tension. 14. The plastic can manufacturing apparatus according to item 13. 15. An elastic blade that presses against the outer surface of the roughly finished cylinder on the mandrel, a mechanism for supplying molten plastic onto the blade, and a mechanism for heating the blade;
A plastic can manufacturing apparatus comprising a pressing force transmission mechanism so that the blade is brought into pressure contact with the cylinder with a substantially uniform pressing force. 16. The plastic can manufacturing apparatus according to claim 15, wherein the pressing force transmission mechanism has a mandrel vibration absorption mechanism to transmit a uniform pressing force.