JP4727823B2 - Manufacturing method of easy-to-open can lid - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention is an easy opening canLidThe present invention relates to a manufacturing method, and particularly to stabilization of an opening force of a planned opening portion of a center push end.
[0002]
[Prior art]
At present, in the can lid, a planned opening portion surrounded by a broken line is formed in the central plate portion of the lid, and a tab fixed to a part of the planned opening portion is pulled up so that the planned opening portion is An easy open end is widely used that pushes in and forms an opening in the lid.
However, this type of easy-open can lid requires a device for manufacturing a tab separately from the end, and thus the manufacturing cost increases.
[0003]
Therefore, an easy open end that does not use a tab has been proposed in, for example, Japanese Patent Laid-Open No. 8-169454, US Pat. No. 4,976,368, and the like.
The easy open end described in JP-A-8-169454, U.S. Pat. No. 4,976,368, etc. is provided with a flange portion on the outer periphery to be engaged with the opening edge of the container, and is surrounded by the flange portion. However, the central plate portion is formed so as to taper out from the flange portion to the outside of the can lid. Then, an opening planned portion is provided at substantially the front end of the central plate portion, a breaking line is formed leaving a part around the planned opening portion, and the inner surface of the central plate portion is covered with the breaking line and sealed. A sealing part is provided. And an opening plan part is pushed in a can lid inward along a fracture line, and an opening is formed. In this specification, such a can lid is referred to as a center push end (hereinafter referred to as CPE).
[0004]
This CPE can be easily opened and has a shape that makes it easy to drink or pour beverages and the like enclosed in a can body. .
[0005]
[Problems to be solved by the invention]
By the way, in CPE, in order to reduce the force required for opening operation and improve the openability, in many cases, the periphery of the planned opening portion is configured as a break line penetrating in the plate thickness direction. In order to improve the sealing performance of the can lid, a sealing agent such as plastisol is applied along the breaking line on the inner surface of the can lid.
[0006]
However, even in the case of the CPE, in reality, the coating amount for each can lid and the thickness of the sealant vary widely, and if the sealant is thick, the force required for opening increases. On the other hand, if the thickness is small, there is a disadvantage that the sealing performance is poor. Therefore, in general, the periphery of the planned opening is configured as a score line, and the periphery of the planned opening is broken compared to a can lid that uses a tab that stabilizes the opening force by managing the remaining thickness of the score line. In a CPE that is often configured as a line, the management of the thickness of the sealing portion is very important in stabilizing the opening force.
[0007]
On the other hand, for example, Japanese Examined Patent Publication No. 58-10151 is not related to CPE, but as a technique for making the thickness of the plastisol of the can lid having a short distance between the plastisol and the bottom of the countersink a desired thickness, Plastisol is poured out and coated, heat-cured on the can lid, and while the plastisol is hot, a silicon rubber coating roll with a peripheral speed that synchronizes with the speed of the conveyor is contacted to make the thickness of the plastisol desired Is disclosed.
[0008]
However, in the technique disclosed in Japanese Patent Publication No. 58-10151, the silicon rubber roll is brought into contact with the plastisol applied to the inner surface of the can lid. It is necessary to overcome the silicon rubber coating roll while being compressed.
Here, in the easy-to-open can lid as described in, for example, Japanese Patent Publication No. 58-10151, the distance between the plastisol and the bottom of the counter sink is as short as about 2.5 mm. You can get over the sink.
[0009]
On the other hand, in an easy-open can lid such as CPE where the distance between the plastisol and the counter sink bottom is as long as about 10 mm, for example, the silicon rubber coating roll is not compressed and the counter sink cannot be overcome. For this reason, it is necessary to change to the material which can enlarge the compression amount of silicon rubber.
However, if a material capable of increasing the amount of compression is used, the plastisol cannot be formed flat.
[0010]
Therefore, the conventional technology for making the plastisol of the easy-to-open can lid with a short distance between the plastisol and the bottom of the counter sink has a desired thickness, and in the CPE where the distance between the plastisol and the bottom of the counter sink is long, the plastisol is made the desired thickness. I was not able to adopt it.
For this reason, among the easy open ends that do not use a tab, stabilization of the opening force has been strongly desired even in the case of a CPE that is easy to drink or pour, such as a beverage enclosed in a can body.
[0011]
  The present invention has been made in view of the above-mentioned problems of the prior art, and its purpose is a can capable of stabilizing the opening force of the planned opening portion at the center push end.LidIt is to provide a manufacturing method.
[0015]
[Means for Solving the Problems]
in frontIn order to achieve the above-mentioned object, the manufacturing method of the easy opening lid according to the present invention is such that a substantially central portion of the central plate portion is formed so as to taper out from the outer periphery to the outside of the can lid, and the central plate portion A forming step of forming a break line by leaving a part around the planned opening portion at the tip, and the break line and the break line on the inner side surface of the central plate after the forming step, the opening planned portion and the center An application step of applying a sealing agent to cover at least the edge of the plate portion to form a sealing portion, and a manufacturing method of an easy-to-open can lid, wherein the sealing agent uses a plastic material, and a heating step. A cooling process and a homogenization process are provided.
[0016]
Here, the heating step heats the sealed portion of the can lid after the coating step.
Moreover, the said cooling process cools the sealing part of the can lid after the said heating process.
The homogenization step is performed on the inner surface of the can lid with the support tool pressed from the direction substantially orthogonal to the outer surface of the can lid with the sealing portion of the can lid after the cooling step interposed therebetween. The molding tool having a pressing surface having a smaller diameter than the inner side surface of the center plate portion is pressed against the sealing portion from a direction substantially orthogonal to the inner surface of the central plate portion with a predetermined pressure, and the thickness of the sealing portion is in the circumferential direction of the planned opening Ensure uniform and desired thickness.
[0017]
In order to achieve the above object, the method of manufacturing an easy-to-open can lid according to the present invention comprises forming a substantially central portion of the central plate portion so as to project outwardly from the outer periphery of the central plate portion in a tapered manner. Forming a break line by leaving a part around the planned opening at the tip of the part, and sandwiching the break line and the break line on the inner surface of the central plate part after the forming step, And an application step of applying a sealing agent so as to cover at least an edge of the central plate portion to form a sealing portion, wherein the sealing agent uses a plastic material, and a heating step. And a homogenization step and a cooling step.
[0018]
Here, the heating step heats the sealed portion of the can lid after the coating step.
In the uniformizing step, a molding tool having a pressing surface having a smaller diameter than the inner surface at the front end of the central plate portion is applied at a predetermined pressure to the sealing portion from a direction substantially orthogonal to the inner surface of the can lid after the heating step. The thickness of the pressing and the sealing portion is made uniform in the circumferential direction of the planned opening portion and a desired thickness.
[0019]
The cooling step cools the sealed portion of the can lid after the homogenization step.
In the method of manufacturing an easy-to-open can lid according to the present invention, the molding step includes a portion that is surrounded by a spout break line at the tip of the center plate portion of the can lid as the planned opening portion. Forming a vent outlet planned portion surrounded by a break line for vent holes on the inner peripheral side of the spout at the tip of the central plate portion of the can lid,
The coating step sandwiches the spout break line and the spout break line on the inner surface of the central plate portion after the molding step, and covers at least the edge of the spout planned portion and the center plate tip. And forming the sealing portion for the spout and sandwiching the break line for the vent and the break line for the vent on the inner side surface of the central plate portion, and at least the edge of the vent portion and the spout portion Form a vent seal to cover
The homogenizing step presses the forming tool against the sealing portion for the spout with a predetermined pressure from a direction substantially orthogonal to the inner surface of the can lid, and the thickness of the sealing portion for the spout is the planned spout portion The molding tool is pressed against the vent sealing portion with a predetermined pressure from a direction substantially orthogonal to the inner surface of the can lid, and the vent sealing portion It is preferable that the thickness is uniform in the circumferential direction of the planned vent and the desired thickness.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a state where an easy opening can lid according to this embodiment is wound around a can body, FIG. 2 is a similar top view, and FIG. 3 is an enlarged view of a main part of the can lid, Each is shown.
[0021]
In the figure, the easy opening can lid 10 according to the present embodiment is provided with a flange portion 16 on the outer periphery in order to wind around the opening edge portion 14 of the cylindrical can body 12. The central plate portion 18 is formed with an annular protruding portion 20 that protrudes outward from the flange portion 16 on the central axis in the axial direction.
[0022]
A panel wall 24 that closes the opening of the protrusion 20 is formed between the tip edge 22 of the protrusion 20 and the flange 16 in the axial direction. A folded portion 26 that is folded at least in triplicate is formed in a portion away from the peripheral edge portion of the panel wall 24.
A substantially circular second layer 26a, 26b, 26c constituting the folding portion 26 is surrounded by a first break line (spout line for spout) 28 leaving a first hinge part 29 in a lowermost layer 26c. One opening scheduled portion (scheduled outlet portion) 30 is formed. The first breaking line 28 is broken by a pressing force equal to or higher than a predetermined pressure.
[0023]
In addition, in order to make it easy to push the first opening planned portion 30 into the container, the first hinge portion 29 may be provided with a score line having a depth that does not break by the pressing force.
The inner surface of the can lid is coated with a plastisol (sealing agent for spout) 32 that covers and seals the first breaking line 28.
[0024]
Further, in the present embodiment, a substantially circular second opening surrounded by a second break line (vent hole break line) 34 leaving the second hinge part 35 on the inner peripheral side of the first opening scheduled part 30. A planned portion (scheduled vent portion) 36 is formed. The second breaking line 34 is broken by a pressing force equal to or higher than a predetermined pressure. The second break line 34 completely cuts the panel wall 24 in the thickness direction, leaving the second hinge portion 35. In the second break line 34, the end edge portion of the second scheduled opening portion 36 is superposed on the inner surface of the can lid at the inner peripheral end edge portion of the first pre-opened portion 30, and the superposed portion 38 on the inner surface of the can lid is Covered and sealed with plastisol (sealant for vent) 40.
[0025]
In this way, by configuring the CPE according to the present embodiment, the lid can be easily opened without using a tab separate from the end, and a beverage or the like enclosed in the can body is easy to drink, or It becomes easy to pour.
What is characteristic in the present embodiment is that the thickness of the plastisol 32 that covers and seals the first breaking line 28 is uniform in the circumferential direction with respect to the thickness direction of the lowermost layer 26c of the folding portion 26 and has a desired thickness. It is formed.
[0026]
Therefore, the opening force of the first opening 30 can be stabilized by making the thickness of the plastisol 32 covering and sealing the first breaking line 28 constant in all can lids.
Further, in the present embodiment, the surface of the plastisol 40 that covers and seals the polymerization portion 38 is formed in a uniform and desired thickness in the circumferential direction with the polymerization portion 38 of the second opening scheduled portion 36. Therefore, the thickness of the plastisol 40 that seals the polymerization portion 38 can be made constant in all can lids. Thereby, since the opening force of the second opening scheduled portion 36 can be stabilized, the opening force of the first opening scheduled portion 30 can be further stabilized.
[0027]
Further, in the present embodiment, since the second opening planned portion 36 having a smaller diameter than the first opening planned portion 30 is formed, even if the can internal pressure is high, the opening is made with a relatively small force due to the small diameter. By pushing the possible second opening planned portion 36 into the can and forming the opening, the gas in the can escapes from the opening to the outside, and the internal pressure of the can decreases. For this reason, even when the internal pressure of the can is high, the user can stabilize the first planned opening 30 with the finger by pushing the second planned opening 36 into the can as described above and forming the opening. It can be easily opened by pressing with the opening force.
[0028]
First embodiment
FIG. 4 shows an apparatus for manufacturing an easy-to-open can lid according to this embodiment. In this embodiment, plastisol is applied to a single can lid that has not been tightened with a can body, and then heated. It is assumed that the thickness of the plastisol is made uniform in the previous stage after cooling.
In the drawing, the manufacturing apparatus 50 includes a lid forming means 52, a plastisol applying means 54, and a first conveying conveyor 56 driven in the subsequent stage, so that the carrying star wheel 60 into the heating zone 72 is counteracted. While rotating clockwise, the guide bar 62 and the carrying star wheel 64 are rotated clockwise, the transfer star wheel 66 is rotated counterclockwise, and the guide bar 84 is rotated clockwise for carrying out. The star wheel 88 rotates counterclockwise, and the carry-out star wheel 68 rotates clockwise.
[0029]
That is, in the forming means 52, a flat plate made of metal such as an aluminum alloy is punched into a cup shape and protruded so that the diameter of the bottom of the cup is reduced, thereby forming a protruding portion. A panel wall is formed that indents the central part of the projecting part inward and closes the opening of the projecting part, and at least a triple fold is formed on the part away from the peripheral edge of the panel wall. A flange portion is formed on the peripheral edge of the can lid, and a substantially circular second scheduled opening portion surrounded by a second break line that completely cuts the panel wall in the thickness direction is formed at the center portion of the panel wall. Then, when the edge portion of the second opening planned portion is polymerized on the inner surface of the can wall of the inner peripheral edge portion of the panel wall and the first breaking line is formed in the lowermost layer of the folding portion, the can lid 10 is The plastisol 32, 40 is applied to the first rupture line and the second rupture line, respectively.
[0030]
As the plastisol, for example, a dispersion liquid in which fine particles of an acrylic resin and an inorganic filler (barium sulfate) and the like are dispersed in a plasticizer (acetyltributyl citrate, glycerin ester, etc.), such as a liquid at room temperature, is used. .
In addition, from the viewpoints of openability and airtightness, the application amount is, for example, 140 mg for the first break line and 35 mg for the second break line as the center value.
[0031]
However, in this case, for example, the coating amount of plastisol 32 has a variation of about ± 15 mg with respect to the central value of 140 mg, and it was impossible to keep the management width within ± 5 mg in the experimental results. In addition, even with samples having the same coating amount, the plastisol thickness variation is about 0.28 to 0.34 mm for plastisol 32 and 0.13 to 0.17 mm for plastisol 40. Even with one sample, the entire circumference is uniform. It was not plastisol thickness. With the current coating technology, it is difficult to produce CPE that cannot control the plastisol thickness and that can provide a stable opening force.
[0032]
Therefore, what is characteristic in the present embodiment is that in CPE, the thickness of the plastisol is uniform in the circumferential direction of the planned opening portion in a state of being easily deformed after the heating process of the can lid coated with plastisol and before cooling. And the uniformization process was performed so as to obtain a desired thickness. For this purpose, in the manufacturing apparatus 50 according to the present embodiment, the uniformizing means 79 is installed between the heating zone 72 and the cooling zone 82. That is, the can lid 10 after the plastisol application is carried to the heating zone 72 by the carrying star wheel 60. In the heating zone 72, hot air is introduced from above, and the upper part is hot relative to the lower part. Therefore, the can lid delivered below the first drum unit, and the plastisol applied to the can lid are It is in a preheated state.
[0033]
The can lid held at the lowermost stage is pushed forward with the rotation of each guide bar 62 and moves up in the heating zone 72. It is heated at 210 ° C. in the course of 3 minutes. Then, the acrylic resin in the plastisol applied to the can lid melts and dissolves evenly in the plasticizer, and the whole becomes a solid solution, which can be plastically deformed and is softer and easier to mold than after cooling.
[0034]
Here, since the can lid and the plastisol applied to the can lid are preheated, it is possible to ensure foam removal and fluidity of the plastisol.
When the can lid reaches the carry-out port 81, the can lid is transferred to the transfer star wheel 66 and supplied to the cooling zone 82 in the guide 76 of the wheel body 74. Further, the can lid enters the track of the guide bar 84, and in the cooling zone 82, the can lid is cooled by cooling air from below.
[0035]
Here, what is characteristic in the present embodiment is that the uniformizing means 79 is provided in the guide 76 of the wheel main body 74 between the heating zone 72 and the cooling zone 82. The plastisol is homogenized before the heated can lid is cooled.
[0036]
That is, in the guide 76 of the wheel main body 74, as shown in FIG. 5, the tip end 22 of the protruding portion 20 of the can lid 10 is in contact with the conveyor 83. By such a method of operating the forming tool (homogenizing means) 77 in the vertical direction from the direction substantially orthogonal to the inner surface of the can lid 10, for example, in a configuration interlocking with the rotation shaft of the transfer star wheel 66. The plastisol 32 that covers and seals the first breaking line on the inner surface of the protruding portion 20 of the can lid 10 and the plastisol 40 that covers and seals the second breaking line are predetermined. Pressing with pressure.
[0037]
For this reason, in this embodiment, the thickness of the plastisols 32 and 40 of the can lid after plastisol application is uniform in the circumferential direction of each corresponding opening planned portion and becomes a desired thickness by the uniformizing means 79.
As described above, in this embodiment, the forming tool 77 is entered into the CPE having a long distance between the plastisol and the bottom of the counter sink, and the first fracture line on the inner surface of the protruding portion from the direction substantially perpendicular to the inner surface of the can lid The molding tool 77 is configured with a smaller diameter than the inner surface of the protruding portion 20 so that the plastisol 32 that covers and seals the plastisol 32 and the plastisol 40 that covers and seals the second breaking line can be pressed at a predetermined pressure. It consists of the length of the direction. Further, since the second break line protrudes outward from the first break line, the pressing surface that presses the plastisol 40 that covers and seals the second break line covers and seals the first break line. It is formed so as to protrude from the pressing surface for pressing the plastisol 32. Further, the forming tool 77 is made of, for example, silicon rubber or the like, and the pressing surface can be in close contact with the inner surface of the can lid if it is somewhat uneven.
[0038]
For this reason, the thickness of the plastisol applied to the CPE having a long distance between the plastisol and the counter sink bottom can be made uniform in the circumferential direction and desired.
In addition, since the easy opening can lid 10 according to the present embodiment is wound around the opening edge portion 14 of the cylindrical can body 12, a flange portion 16 is provided on the outer periphery as shown in FIG. The central plate portion 18 is formed with an annular protruding portion 20 that protrudes outward from the flange portion 16 on the central axis in the axial direction.
[0039]
The can lid with the plastisol having a uniform thickness enters the track of the guide bar 84 and is transported to the cooling zone 82. In the cooling zone 82, the can lid is cooled by cooling air from below. .
Therefore, the temperature of the can lid can be gradually lowered from a state in which the temperature immediately after being taken out of the heating zone is high.
[0040]
The can lid held at the uppermost stage of the cooling zone 82 descends in the cooling zone. And it cools in the descending process for 3 minutes, As a result, plastisol is baked on a can lid. When the can lid reaches the carry-out port 86, it is carried out of the cooling zone 82 as it is by the carry-out star wheel 88, delivered to the carry-out star wheel 68, and then carried to the subsequent stage by the second carry-out conveyor 90. . Thus, the plastisol of the can lid is dried by heating and cooling.
[0041]
As described above, according to the manufacturing apparatus according to the present embodiment, the forming tool 77 is caused to enter the CPE having a long distance between the plastisol and the bottom of the countersink from the direction substantially perpendicular to the inner surface of the can lid. The plastisol that covers and seals the first fracture line on the inner surface of the protrusion and the plastisol that covers and seals the second fracture line from a direction substantially orthogonal to the inner surface of the lid can be pressed at a predetermined pressure. The forming tool 77 according to the embodiment is configured with a smaller diameter than the inner side surface of the projecting portion and with a sufficient length in the pressing direction.
[0042]
As a result, while the plastisol is still applied, the surface of the plastisol is usually in a spherical state in which the central part is swollen, but the forming tool 77 is made to enter the CPE having a long distance between the plastisol and the bottom of the countersink. Therefore, by forming the surface of the plastisol flat, the thickness of the plastisol covering and sealing the first breaking line and the thickness of the plastisol covering and sealing the second breaking line are uniform in the circumferential direction. The desired thickness can be obtained.
[0043]
Therefore, according to the present embodiment, the plastisol thickness, which has been extremely difficult in CPE in the past, can be made uniform in the circumferential direction of the planned opening and a desired thickness, so that the plastisol thickness can be easily managed. be able to. Thereby, the can lid | cover which can maintain the stable opening force can be manufactured.
Moreover, according to the present embodiment, even if the application amount is reduced as compared with the conventional case, the desired thickness can be obtained, so that the strength is not affected and rationalization can be achieved.
[0044]
Further, according to the present embodiment, the plastisol thickness is made uniform by the uniformizing means 79 provided in the guide 76 of the wheel main body 74 in the transfer star wheel 66 for transferring from the heating zone 72 to the cooling zone 82. As a result, the thickness of the plastisol is made uniform in a state where the plastisol is softer and easier to mold after cooling, so that it is not necessary to provide a support tool to be described later, and the apparatus can be downsized.
[0045]
In the present embodiment, as the drying means, the easy opening lid that is held in the spiral groove is moved in the length direction of the spiral groove by circulating and moving in the space between the cylindrical inner peripheral wall and the outer peripheral wall. Two sets of units each provided with a large number of pressing members that are pressed along are provided. As a result, the spiral groove in the space between the inner peripheral wall and the outer peripheral wall serves as a conveyance path for the can lid, and the conveyance path itself is not configured to rotate. It does not occur on the peripheral wall and the outer peripheral wall. Accordingly, damage to the coating film on the can lid can be prevented.
[0046]
Further, in the drying means according to this embodiment, one unit forms a heating zone in which the can lid is transported from below to above and hot air is supplied from above, and the other unit is below from above. A cooling zone is formed in which the can lid according to the present embodiment is conveyed toward the front and cold air is supplied from below.
As a result, in the drying means according to the present embodiment, in the heating zone, the same effect as preheating is obtained for the can lid positioned below, and the plastisol and the can lid are efficiently heated. On the other hand, in the cooling zone, the can lid immediately after being transported out of the heating zone is not cooled rapidly but gradually cooled, and cold air is applied to the can lid just before being transported out of the cooling zone. Since it can be sprayed well, the plastisol and can lid are cooled efficiently and reliably.
[0047]
Furthermore, in the drying means according to the present embodiment, the easy opening can from the end of the spiral groove provided in the unit constituting the heating zone to the start end of the spiral groove provided in the unit constituting the cooling zone. A delivery member for delivering the lid is provided.
As a result, the can lid that has completed the heating process in the heating zone can be quickly supplied to the cooling process, so that the processing efficiency of the entire apparatus can be achieved.
[0048]
Second embodiment
FIG. 6 shows an apparatus for manufacturing an easy-to-open can lid according to the second embodiment of the present invention. In this embodiment, plastisol is applied to a single can lid that has not been tightened with the can body. Thereafter, it is assumed that the thickness of the plastisol is made uniform after the heating step and the cooling step. In addition, the code | symbol 100 is added to the part corresponding to said 1st embodiment, and description is abbreviate | omitted.
[0049]
In the present embodiment, the can lid after the plastisol is baked, with the inner surface facing upward, the equalizing means 179 is installed on the second carry-out conveyor 190, which is the subsequent stage of the cooling zone 182, and after the cooling step The thickness of the plastisol of the can lid is uniform in the circumferential direction of the planned opening and a desired thickness.
Here, since the plastisol after heating and cooling is cured, a large pressing force must be applied to form the plastisol surface into a flat shape.
However, when the plastisol is pressed with the tip edge of the protruding portion of the can lid in contact with the conveyor, there is a gap between the outer surface of the can lid on the broken line covered with the pressed plastisol and the conveyor. Therefore, the vicinity of the breaking line may be deformed by the pressing force.
[0050]
Therefore, as shown in FIG. 7, after applying plastisol, heating and cooling, the molding tool 177 is pressed from the inner surface of the can lid in a state where the support tool 192 is pressed in a direction substantially orthogonal to the outer surface of the can lid. , 140 squeezes the plastisols 132, 140 in a spherical state with the center portion swelled without deforming the can lid even when a large pressing force is applied, In a CPE having a long counter sink bottom, the thickness can be uniform in the circumferential direction and can be set to a desired thickness.
[0051]
As described above, according to the easy-open can lid manufacturing apparatus 150 according to the present embodiment, as in the first embodiment, the first breaking line on the inner surface of the protruding portion from the direction substantially perpendicular to the inner surface of the can lid. The molding tool 177 has a smaller diameter than the inner side surface of the protruding portion and has a sufficient pressing direction so that the plastisol 132 that covers and seals the plastisol 140 that covers and seals the second breaking line can be pressed at a predetermined pressure. It consists of the length of.
[0052]
As a result, according to this embodiment, as in the first embodiment, the forming tool 77 enters the CPE having a long distance between the plastisol and the bottom of the countersink from the direction substantially perpendicular to the inner surface of the can lid. Therefore, the thickness of the plastisol 132 that covers and seals the first break line and the thickness of the plastisol 140 that covers and blocks the second break line can be made uniform in the circumferential direction and have a desired thickness.
[0053]
Therefore, the plastisol thickness can be easily managed to a predetermined thickness. Thereby, the can lid | cover which can maintain the stable opening force can be manufactured easily. In addition, even if the coating amount is reduced as compared with the prior art, the desired thickness can be obtained, so that the strength is not affected and rationalization can be achieved.
Further, when the plastisol thickness is made uniform after plastisol heating and cooling as in this embodiment, when the molding tool 177 is pressed against the plastisol 132, 140 at a predetermined pressure, the plastisol 132, 140 on the can lid is applied. Even if the plastisols 132 and 140 are cooled and hardened and are not easily crushed by pressing the support tool 192 from the outer surface, the molding tool 177 is pressed with a sufficient predetermined pressure. 132 and 140 can be pressed. As a result, the thickness of the plastisols 132 and 140 can be obtained in a uniform and desired thickness in the circumferential direction as desired.
[0054]
In addition, this invention is not limited to said each structure, A various deformation | transformation is possible within the range of the summary of invention.
For example, in the above-described configuration, the example in which the pressing surface of the molding tool against the plastisol is configured to be flat has been described. However, the molding tool of the present invention is not limited to this, and as illustrated in FIG. A structure in which a plurality of uneven portions 294 are provided on the pressing surface against the plastisol to form an uneven shape can be used. Thereby, since the thickness of the plastisol can be made uniform, the spring back of the plastisol can be more significantly prevented as compared with a flat one.
[0055]
Moreover, in the said structure, although the example which comprised the cover body from metal flat plates, such as an aluminum alloy plate, was demonstrated, the can lid of this invention is not limited to this, For example, surface treatment steel plates etc. Other materials can be used. Moreover, it is more preferable that an inner surface film made of a synthetic resin is formed in advance on the inner surface of the flat plate. This inner surface film is formed from a protective paint or a resin film, and as the paint, for example, any protective paint made of a thermosetting and thermoplastic resin, for example, a modified epoxy paint such as a phenol-epoxy paint, an amino-epoxy paint, It is more preferable to use it alone or in combination of two or more kinds of vinyl such as a chloride-vinyl acetate copolymer and an epoxy-phenol-modified vinyl paint, or a modified vinyl paint. Moreover, as a resin film, the polyethylene resin which has ethylene-terephthalate as a basic composition, for example, polyethylene terephthalate (PET), and also a copolymer such as polyethylene terephthalate-isophthalate (PET / I) can be applied. Moreover, when a resin film is used for the inner surface coating, the resin film may be unstretched or biaxially stretched.
[0056]
【The invention's effect】
  As explained aboveThe bookAccording to the manufacturing method of the easy-to-open can lid according to the invention, the plastisol is made of a plastic material, and has a pressing surface having a smaller diameter than the inner surface of the center plate portion at the plastisol from a direction substantially perpendicular to the inner surface of the can lid. The forming tool is pressed at a predetermined pressure, and the thickness of the plastisol is uniform in the circumferential direction of the planned opening portion and is provided with a uniformizing step.
  As a result, it is possible to obtain a can lid that can stabilize the opening force of the planned opening portion, which has been extremely difficult in the past at the center push end.
  In the method of manufacturing the easy-to-open can lid according to the present invention, the vent hole planned portion is formed on the inner peripheral side of the spout planned portion at the tip of the central plate portion, and the thickness of the vent sealing portion is determined to be the vent vent By being uniform in the circumferential direction of the portion and having a desired thickness, a can lid can be obtained in which the opening force of the planned opening portion is further stabilized.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a state where an easy opening lid according to an embodiment of the present invention is wound around a can body.
FIG. 2 is a top view showing a state where an easy opening lid according to an embodiment of the present invention is wound around a can body.
FIG. 3 is an enlarged view of a main part of an easy opening lid according to an embodiment of the present invention.
FIG. 4 is an explanatory diagram of a schematic configuration of a device for manufacturing an easy-to-open can lid according to the first embodiment of the present invention.
FIG. 5 is an explanatory diagram of a uniformizing process characteristic in the first embodiment of the present invention.
FIG. 6 is an explanatory diagram of a schematic configuration of a device for manufacturing an easy-to-open can lid according to a second embodiment of the present invention.
FIG. 7 is an explanatory diagram of a uniformizing process characteristic in the second embodiment of the present invention.
FIG. 8 is a modified example of a forming tool which is an example of a manufacturing apparatus according to an embodiment of the present invention.
[Explanation of symbols]
10 Easy opening can lid
16 Flange
18 Central plate
20 Protrusion
28 First break line (break line for spout)
30 Planned first opening (planned outlet)
32 plastisol (sealing agent for spout)
34 Second breaking line (breaking line for vent)
36 Planned second opening (planned vent)
40 plastisol (sealant for vents)

Claims (3)

A molding step in which a substantially central portion of the central plate portion is formed so as to taper out from the outer periphery to the outside of the can lid, and a break line is formed leaving a portion around the planned opening portion at the front end of the central plate portion. Then, the sealing line is formed by applying the sealing agent so as to cover at least the edges of the planned opening part and the central plate part, sandwiching the breaking line and the breaking line on the inner side surface of the central plate part after the molding step. In the manufacturing method of the easy opening can lid provided with an application step,
The sealant uses a plastic material,
A heating step of heating the sealed portion of the can lid after the coating step;
A cooling step for cooling the sealed portion of the can lid after the heating step;
A direction substantially orthogonal to the inner surface of the can lid in a state where the support tool is pressed from a direction substantially orthogonal to the outer surface of the can lid, with the sealing portion of the can lid after the cooling step interposed therebetween. A molding tool having a pressing surface having a smaller diameter than the inner surface of the front end of the central plate portion is pressed to the sealing portion with a predetermined pressure, and the thickness of the sealing portion is uniform in the circumferential direction of the planned opening portion and a desired thickness. A homogenization process to become,
An easy-to-open can lid manufacturing method characterized by comprising: A molding step in which a substantially central portion of the central plate portion is formed so as to taper out from the outer periphery to the outside of the can lid, and a break line is formed leaving a portion around the planned opening portion at the front end of the central plate portion. Then, the sealing line is formed by applying the sealing agent so as to cover at least the edges of the planned opening part and the central plate part, sandwiching the breaking line and the breaking line on the inner side surface of the central plate part after the molding step. In the manufacturing method of the easy opening can lid provided with an application step,
The sealant uses a plastic material,
A heating step of heating the sealed portion of the can lid after the coating step;
Pressing a molding tool having a pressing surface having a smaller diameter than the inner surface at the tip of the central plate portion with a predetermined pressure from the direction substantially perpendicular to the inner surface of the can lid after the heating step, the thickness of the sealing portion Is uniform in the circumferential direction of the planned opening and a desired thickness,
A cooling step for cooling the sealed portion of the can lid after the homogenization step;
An easy-to-open can lid manufacturing method characterized by comprising: In the manufacturing method of an easy opening can lid according to claim 1 or 2 ,
The forming step forms, as the planned opening portion, a planned spout portion of the content surrounded by a spout break line at the tip of the central portion of the can lid, and the center of the can lid On the inner peripheral side of the planned spout portion at the front end of the plate portion, a vent portion planned portion surrounded by a broken portion for the vent port is formed,
The coating step sandwiches the spout break line and the spout break line on the inner surface of the central plate portion after the molding step, and covers at least the edge of the spout planned portion and the center plate tip. And forming the sealing portion for the spout and sandwiching the break line for the vent and the break line for the vent on the inner side surface of the central plate portion, and at least the edge of the vent portion and the spout portion Form a vent seal to cover
The homogenizing step presses the forming tool against the sealing portion for the spout with a predetermined pressure from a direction substantially orthogonal to the inner surface of the can lid, and the thickness of the sealing portion for the spout is the planned spout portion The molding tool is pressed against the vent sealing portion with a predetermined pressure from a direction substantially orthogonal to the inner surface of the can lid, and the vent sealing portion A method for manufacturing an easy-to-open can lid, characterized in that the thickness is uniform in the circumferential direction of the planned vent portion and a desired thickness.

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