JP2012101374A - Apparatus for producing liner for cap, method for producing the same, and liner for cap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for producing a liner for the cap which can produce a liner for a cap in which a ring-shaped sealing layer is formed on a hard disk (sliding layer), to provide a method for producing the same, and to provide a liner for the cap produced by the production method.SOLUTION: The apparatus 1 for producing the liner for the cap is provided with: a disk-shaped sliding layer; and a ring-shaped sealing layer being a synthetic resin laminated on the sliding layer and more flexible than the same. The space therebetween is provided with: a fixed template 4 in which a sheet 3 for a liner can be installed; and a movable template 5 which can be separated/contacted to the fixed template. The apparatus is further provided with: an injection mold 8 of subjecting the synthetic resin 7 melted into a cavity to injection molding to form a sealing layer; an injection unit 9 of injecting the synthetic resin into the injection mold; and a sheet cut mechanism 10 of cutting the sheet for the liner in a state of being set on mold clamping into a disk-shape at the outside more than the cavity and in such a manner that the center is the same.

Description

  The present invention relates to an apparatus and a method for manufacturing a cap liner excellent in openability, sealing performance and hygiene, and a cap liner.

  Many metal caps and plastic caps used in glass bottles, aluminum bottle cans, PET bottles, etc. use liner materials. In particular, a liner is essential for a metal cap, and synthetic resin is widely used for this liner. This metal cap is a cap shell made by punching and molding several times on both sides of an aluminum thin plate, tin thin plate, chrome-plated thin plate, etc., and pre-molded into a disk shape (disk shape) Method (disk insertion method), method of heat bonding at the center after inserting the disk (disk insertion bonding method), method of pouring a liner material into the shell like polyvinyl chloride and heating and bonding at the same time as gelation ( A lining method), a method in which a molten resin is put into a shell and pressed (in-shell mold method) are known.

  These methods have their merits and demerits, and the disk insertion method and the disk insertion bonding method are relatively inexpensive in manufacturing equipment, but because the liner sheet is a single layer, there are many inferior oxygen barrier properties, and the sheet is changed into a disk shape. Because of the punching, liner scraps are generated and the yield of the material is poor. In addition, these disc-shaped liners are recyclable. However, in consideration of cost and hygiene, punched scraps are usually not reused for the same. Furthermore, since it is a sheet | seat, the center part which is not related to sealing performance cannot be decreased, but a liner weight becomes large.

  On the other hand, in the lining method, the liner material can be disposed only in the seal portion, and the amount used as a liner for the cap can be reduced. However, since the material is mainly vinyl chloride sol, there is a concern in terms of hygiene. There is. The in-shell mold method is relatively efficient with regard to the amount of liner material used, but is not suitable for low-volume production because it is suitable for mass production, and the liner material is extruded from an extruder and cut in a semi-molten state. A material having poor extrudability cannot be used, and usable materials are limited. Moreover, since the opening torque value generally increases, there is a tendency to frequently use a lubricant. In addition, since the melted liner material is supplied to the central portion of the shell and is embossed with a cooled mold, the liner is also disposed in the central portion of the cap. This means that the flexible liner material comes into contact with the content liquid.

  On the other hand, a liner material having a multilayer structure has been proposed. This is a method in which a resin with high hardness and a resin with low hardness are bonded together, punching moldability with high hardness resin, shape retention after sealing, and sealing performance with low hardness resin (patent) Reference 1). This multi-layer liner material provides good sealing properties and openability, but punches into a disk shape from the sheet and generates scraps to form a liner, which increases the cost of the liner itself. In addition, since the hard member and the soft member are bonded to each other, they are molded by coextrusion, so that the punched scrap cannot be recycled and the effective use rate of the material is low.

As one of the countermeasures, a disk is punched out of a hard sheet, inserted into a cap shell, and then a molten soft elastomer extruded from an extruder is placed on the hard and embossed with a cooled mold. The method is being studied.
This method is a relatively good method, but requires a disk punching / inserting machine and an in-shell molding machine. Although this liner is superior in performance, these machines are so expensive that they are suitable for mass production and not suitable for small production. Also, because the liner is bonded to the shell, it means that the flexible liner contacts the contents of the container. In general, since a flexible liner material has a large amount of elution with respect to the contents, the area in contact with the contents is preferably as small as possible. If the amount of elution is large, it may become unusable depending on the contents.

Japanese Patent Laid-Open No. 2007-119059

The liner needs to be flexible in order to ensure complete sealing between the container mouth and the cap. For this reason, cork, various rubbers, various elastomers, etc. are normally used for the liner material of a metal cap. Almost all of them have a large amount of elution in elution tests with various solvents in hygiene tests, and sometimes exceed standards. In particular, for oily food applications, there is a regulation that the elution test is performed with n-heptane and the elution amount must be 30 ppm or less, depending on the type of material. This condition severely against the liner material, typically performs dissolution test at a rate of 1 cm ^{2/2 ml,} but if the cap has been observed inverted method. However, it may not be compatible depending on the type of liner material. In particular, a liner that requires flexibility and a liner that requires heat resistance often dissolve, and may not meet the standards.

  As a countermeasure, the liner is made into a ring shape. In particular, a liner using a vinyl chloride sol, a water-based rubber or the like is used for a wide-mouthed cap. Since these are sols, they can be ring-lined from the nozzle in a band shape. By heating this, it is gelled and can be used as a liner. Therefore, the contact between the flexible liner having a large amount of elution and the contents can be reduced. However, in the case of the in-shell mold method, in which a liner in the form of a sheet or a melted liner is dropped on the center of the cap shell and then the liner is pushed to the periphery with a mold, the liner is formed on the entire inner surface of the cap. The area that comes into contact with the contents increases. In addition, in the case of the in-shell mold method in which the molten resin is dropped on the center of the cap and then the liner is pushed to the periphery of the inner surface of the cap with a cooled mold, the limit that spreads because the temperature decreases as the resin goes to the periphery In addition, since the peripheral liner remains strained, it cannot be applied to a wide-mouth cap.

  For metal caps, so-called sheet mold type liners (capable of in-shell molding of a flexible material such as elastomer after inserting a hard sheet into the cap shell) also have good properties with hermeticity and openability. However, since the elastomer part of the liner covers the entire inner surface of the cap, the amount of elution in the hygiene test is not different from that of ordinary in-shell mold type liners. It may not be used for products.

  The present invention has been made in view of the foregoing problems, and a cap liner manufacturing apparatus capable of producing a cap liner in which a ring-shaped sealing layer is formed on a hard disk (sliding layer), and An object of the present invention is to provide a production method and a cap liner produced by this production method.

  The present invention employs the following configuration in order to solve the above problems. That is, the cap liner manufacturing apparatus of the present invention includes a disk-shaped sliding layer, and an annular sealing layer that is laminated on the sliding layer and is a synthetic resin that is more flexible than the sliding layer. An apparatus for manufacturing a cap liner, comprising: a fixed-side mold plate on which a liner sheet serving as the sliding layer can be installed, and a movable-side mold plate separable from the fixed-side mold plate An injection mold that forms an annular cavity on the installed liner sheet and molds the synthetic resin melted in the cavity to form the sealing layer at the time of mold clamping An injection unit for injecting the synthetic resin melted in the injection mold, and the liner sheet placed in the injection mold in a disc shape with the same center outside the cavity Sheet cutting mechanism Characterized in that it comprises a.

  Moreover, the manufacturing method of the cap liner of the present invention is a manufacturing method of the cap liner using the above manufacturing apparatus, and becomes the sliding layer between the fixed-side mold plate and the movable-side template plate. A step of installing a liner sheet, a step of forming the sealing layer by injection molding the molten synthetic resin into the cavity formed on the liner sheet installed during mold clamping, and the sheet And a step of cutting the liner sheet in a state of being installed in the injection mold by a cutting mechanism into a disk shape with the center being the same outside the cavity.

  The cap liner of the present invention is produced by the above-described method for producing a cap liner of the present invention.

In these cap liner manufacturing apparatuses and manufacturing methods, an annular cavity is formed on the liner sheet by an injection mold, and a molten synthetic resin is injection molded into the cavity to form a sealing layer. The liner sheet, which is installed in the injection mold by the sheet cutting mechanism, is cut into a disk shape with the same center outside the cavity, so the liner sheet that is continuous in large or roll form is cut into a disk shape in advance. It is not necessary to perform this, and the sealing layer injection molding and the liner sheet cutting can be performed at the same time during the injection molding process by being placed in the injection mold as it is.
When producing a liner having an annular sealing layer on the sliding layer, for example, an liner is used to produce a liner sheet, which is punched into a disk shape to form a sliding layer, which is then placed in a mold and used with an injection molding machine. A method of forming an elastomer sealing layer by insert molding, or a method of alternately molding and bonding a sliding layer, which is a hard layer, and an elastomer sealing layer by a two-color molding machine can be considered. When punching out the sliding layer from the sheet, it is arranged in a certain way, set it on the fixed mold plate of the mold that the injection molding machine has opened with a robot etc., and then the mold is closed, and then the elastomer is injection molded into the cavity Must be done in steps. When a cap is produced by these methods, the production cost of the liner is increased, and a special mold and a special production machine (such as a two-color molding machine) are required, so that the production speed is extremely inferior. This increases the cost. In contrast, the cap liner manufacturing apparatus and method according to the present invention do not require a liner sheet to be cut into a disk shape in advance, so that a two-color molding machine or the like is not required and the production cost can be reduced. In addition, the throughput is high and high productivity can be obtained.

  Further, the cap liner manufacturing apparatus of the present invention is characterized in that the sheet cutting mechanism has the fixed side plate or the movable side die so that the tip portion formed as a sharp annular blade portion can be opposed to the liner sheet. A cylindrical sheet cutter is provided on the plate and cuts the liner sheet into a disk shape by the blade portion when clamping the mold.

  That is, in this cap liner manufacturing apparatus, the sheet cutting mechanism is provided on the fixed-side mold plate or the movable-side template so that the tip portion that is a sharp annular blade portion can be opposed to the liner sheet. Since it has a cylindrical sheet cutter that pushes the liner sheet into a disk shape at the blade during clamping, the disk-shaped sliding layer is injection molded by pressing the blade of the sheet cutter against the liner sheet during mold clamping It can be easily cut out while being positioned with respect to the position.

  Further, the cap liner manufacturing apparatus of the present invention is characterized in that the sheet cutting mechanism is set to the same outer diameter as the sliding layer and punched, and the die corresponding to the fixed side template. And the movable side mold plate having a punching hole through which the liner sheet can be punched out in a disk shape by shearing between the fixed side mold plate and the pressed side mold plate.

  That is, in this cap liner manufacturing apparatus, the sheet cutting mechanism has a liner by shearing between a fixed-side mold plate that is a punch and a fixed-side mold plate that is a die that corresponds to the fixed-side mold plate and is pressed. Since the sheet is made up of a movable side plate having a punching hole capable of punching the disc into a disc shape, a disc-shaped sliding layer can be obtained by punching simultaneously with clamping.

The present invention has the following effects.
That is, in the cap liner manufacturing apparatus and method according to the present invention, a synthetic resin is injection-molded on a liner sheet by an injection mold to form an annular sealing layer, and the sheet cutting mechanism is used for the liner. Since the sheet is cut into a disk shape outside the cavity, there is no need to cut the liner sheet continuously in large or roll form into a disk shape in advance, and the injection molding of the sealing layer and the cutting of the liner sheet are performed during the injection molding process. Can be done together. Therefore, according to the present invention, it is possible to efficiently produce a liner with less elution and excellent sealing and unsealing properties.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing an injection mold in a first embodiment of a cap liner manufacturing apparatus and method and a cap liner according to the present invention. In 1st Embodiment, it is sectional drawing which shows a motion etc. of a metal mold | die in order of a manufacturing process. In 1st Embodiment, it is sectional drawing which shows a motion etc. of a metal mold | die in order of a manufacturing process. In 1st Embodiment, it is sectional drawing which shows the produced liner for caps. FIG. 6 is a cross-sectional view showing an injection mold of a cap liner manufacturing apparatus in a second embodiment of a cap liner manufacturing apparatus and method and a cap liner according to the present invention. In 2nd Embodiment, it is sectional drawing of the rough injection mold which shows a mold clamping state and a mold open state.

  Hereinafter, a cap liner manufacturing apparatus and method according to the present invention and a cap liner according to a first embodiment will be described with reference to FIGS. 1 to 4.

  The cap liner manufacturing apparatus 1 of the present embodiment includes a disc-shaped sliding layer 2a shown in FIG. 4 and an annular sealing layer that is laminated on the sliding layer 2a and is a synthetic resin that is more flexible than the sliding layer 2a. 1 to 3, a fixed-side template on which a liner sheet 3 serving as a sliding layer 2a can be placed between each other, as shown in FIG. 1 to FIG. 4 and a movable side mold plate 5 that can be separated from and attached to the fixed side mold plate 4, and at the time of clamping, an annular cavity 6 is formed on the installed liner sheet 3, An injection mold 8 for forming the sealing layer 2b by injection molding the molten synthetic resin 7 into the cavity 6, an injection unit 9 for injecting the molten synthetic resin 7 into the injection mold 8, and injection molding The liner sheet 3 installed in the mold 8 is released from the cavity 6. And a sheet cutting mechanism 10 to cut the center on the side likewise to a disc shape.

The movable side template 5 is a cradle on which the liner sheet 3 can be installed on the installation surface.
The fixed-side template 4 is a cylindrical sheet pressing member 11 that is separable from the installation surface and capable of pressing the liner sheet 3 installed on the installation surface with the tip, and the sheet pressing member 11. A cylindrical outer punch 12 which is arranged on the inner side of the outer punch 12 and is separable from the installation surface and has a step 12a formed at the tip thereof, and a synthetic resin which is slidably provided on the inner peripheral surface of the outer punch 12 and is melted 7 and an inner punch 13 having a gate portion 13a for injecting molten synthetic resin 7 disposed at the inner corner of the cavity 6. That is, an annular cavity 6 corresponding to the sealing layer 2 b is formed between the stepped portion 12 a of the outer punch 12, the tip outer peripheral surface of the inner punch 13, and the liner sheet 3.

  The sheet cutting mechanism 10 is provided on the fixed-side mold plate 4 so that the front end portion which is a sharp annular blade portion 14a can be opposed to the liner sheet 3, and the liner sheet 3 is moved by the blade portion 14a during clamping. A cylindrical sheet cutter 14 that pushes into a disk shape is provided. That is, the sheet cutter 14 is slidably provided between the inner peripheral surface of the sheet pressing member 11 and the outer peripheral surface of the outer punch 12. The sheet pressing member 11 is connected to the base end portion of the sheet cutter 14 with a spring 11a, and is urged toward the movable mold plate 5 by the spring 11a. In the mold open state, the tips of the outer punch 12, the sheet cutter 14, and the sheet pressing member 11 protrude from the inner punch 13 toward the movable mold plate 5 in this order.

  The inner punch 13 is connected to the injection unit 9 and has a sprue 13b which is a flow path of the synthetic resin 7 formed on the central axis and melted, and a flow path of the synthetic resin 7 extending from the sprue 13b to the gate portion 13a. A runner 13c, a heater 13d embedded in the outer periphery of the sprue 13b, a heat insulating space 13e that is a cavity provided at the tip, an air vent channel 13f having one end connected to the cavity 6, and an air vent flow An air vent valve 13g which is connected in the middle of the passage 13f and opens and closes the air escape passage 13f.

The outer punch 12 has a cooling water passage 12b through which cooling water flows.
The movable side template 5 has a suction hole 5a connected to a vacuum source (not shown) formed on the central axis of the fixed side template 4 and receives the blade portion 14a of the sheet cutter 14 on the installation surface. An annular cutter receiving groove 5b is formed.

The cap liner 2 is a bottomed cylindrical shape including a top plate portion and a cylindrical peripheral wall portion hanging from the periphery of the top plate portion, and is installed in a resin or metal cap shell (cap body). As shown in FIG. 4, a sliding layer 2a disposed in contact with the inner surface of the cap shell top plate portion, and an annular sealing layer that is laminated on the sliding layer 2a and is more flexible than the sliding layer 2a 2b.
The sliding layer 2a may be laminated with an intermediate layer disposed between the sealing layer 7b and having gas barrier properties. For example, the intermediate layer is a material having a lower adhesive strength with the sealing layer 2b than the sliding layer 2a and has a higher gas barrier property than the sliding layer 2a and the sealing layer 2b, such as a metal foil or a gas. It is formed of a barrier resin.

The sliding layer 2a and the liner sheet 3 are made of PP (polypropylene), HDPE (high density polyethylene), PVC (polyvinyl chloride), various nylons, PET (polyethylene terephthalate), PAN (polyacrylonitrile), PBT (polybutylene). Terephthalate), PC (polycarbonate) or the like.
Note that the sliding layer 2a and the liner sheet 3 are not necessarily made of synthetic resin, but may be, for example, an aluminum sheet laminated or coated with synthetic resin on both sides.

  The disc-shaped sliding layer 2a and the sealing layer 2b cut out from the liner sheet 3 are completely bonded by selecting an elastomer material for the sealing layer 2b. A surface treatment such as corona discharge treatment, glow discharge treatment, plasma treatment, anchor coat treatment, frame treatment, adhesive coating, etc. may be added to the surface of the film. In this case, the surface treatment may be performed only on the surface bonded to the sealing layer 2b.

As the material of the sealing layer 2b, an elastomer or a blend of a resin and an elastomer shows a good result. As the elastomer, olefin elastomer, styrene elastomer, polyamide elastomer, polyester elastomer, polyurethane elastomer, vinyl chloride elastomer and the like can be used.
In addition, as for the thickness of the sealing layer 2b, 0.1-1.0 mm is preferable, More preferably, it is 0.3-0.8 mm.
The cap liner 2 manufactured by this manufacturing method is suitable for an aluminum PP (pill fur proof) cap, but is also an excellent liner for other caps such as tin screw caps and resin caps. Can be used as

  Next, a method for manufacturing a cap liner using the cap liner manufacturing apparatus of the present embodiment will be described with reference to FIGS.

  First, as illustrated in FIG. 2A, the liner sheet 3 is set between the fixed mold 4 and the movable mold 5 set in the manufacturing apparatus 1. The liner sheet 3 is formed in a roll shape in advance, and is inserted between the fixed mold 4 and the movable mold 5 from the vertical direction. The liner sheet 3 preferably has a thickness between 0.1 mm and 1.0 mm. The liner sheet 3 is desirably the minimum width, although it varies depending on the number of products. The liner sheet 3 is fed in the vertical direction at a constant interval by a guide (not shown).

  Next, as shown in FIG. 2B, the tip of the sheet pressing member 11 first presses the liner sheet 3 by clamping with the fixed side mold plate 4 and the movable side mold plate 5. Further, the sheet pressing member 11 is retracted by contraction of the spring 11 a in a state where the liner sheet 3 is pressed, and the sheet cutter 14 further approaches the liner sheet 3. The sheet cutter 14 moves substantially the same as the outer punch 12.

  As shown in FIG. 2C, the sheet cutter 14 moves relative to the liner sheet 3, and the blade 14a at the tip cuts the liner sheet 3 into a ring shape. In this case, the blade part 14a moves to the middle of the cutter receiving groove 5b. Thereby, the disk-shaped sliding layer 2a is cut | disconnected from the sheet | seat 3 for liners.

  Further, as shown in FIG. 2D, the outer punch 12 and the inner punch 13 are further brought closer to the liner sheet 3, and the outer punch 12 stops by pressing the liner sheet 3. After the outer punch 12 presses and stops the liner sheet 3, the inner punch 13 further moves to the liner sheet 3. As a result, a cavity 6, which is a ring-shaped space, is formed between the stepped portion 12 a of the outer punch 12, the tip outer peripheral surface of the inner punch 13, and the liner sheet 3. Note that the gate portion 13 a is designed to be located at the inner corner of the cavity 6.

  In this state, as shown in FIG. 3 (a), the molten synthetic resin 7 sent from the injection unit 9 is filled into the cavity 6 from the gate portion 13a through the sprue 13b and the runner 13c. Molded. At this time, the synthetic resin 7 injected in an annular shape is completely bonded to the sliding layer 2a. Moreover, the sliding layer 2a cut | disconnected circularly is made into the state adsorb | sucked by the suction hole 5a made into the negative pressure state.

  As shown in FIG. 3B, the synthetic resin 7 injected into the cavity 6 is cooled by the outer punch 12 and the inner punch 13 to form an annular sealing layer 2b. The outer punch 12 is cooled by cooling water flowing in the cooling water flow path 12b as a cooling mechanism. The inner punch 13 incorporates a hot runner heater 13d, but the air escape passage 13f serves as a heat insulating layer. Furthermore, the heat insulating space 13e on the tip side also plays a role of a heat insulating layer. For this reason, even if the synthetic resin 7 is injected, there is a sufficient cooling effect.

  Next, as shown in FIG. 3C, after the injected synthetic resin 7 is cooled to form the sealing layer 2 b, the movable mold plate 5 side moves and separates from the fixed mold plate 4. . At this time, the sliding layer 2a is still pressed by the movable side template 5 in a negative pressure state. At this time, the inner punch 13 is first separated from the movable side mold plate 5 leaving the outer punch 12 after the injection molding, so that the synthetic resin 7 of the gate portion 13a is cut.

  As shown in FIG. 3 (d), the movable side mold plate 5 further moves and is completely separated from the fixed side mold plate 4. In this state, the suction hole that was in a negative pressure state by automatic valve switching. On the contrary, air is blown out from 5a, and the produced cap liner 2 is pushed out. The cap liner 2 falls below the manufacturing apparatus 1 and is carried to the next liner filling step. The punching waste of the liner sheet 3 at this time can be made into chips and used as a raw material for the liner sheet 3.

In the present embodiment, the sheet cutter 14 is incorporated on the fixed mold 4 side, but the sheet cutter 14 can be installed on the movable mold 5 side.
In addition, the liner sheet 3 is not completely cut by the sheet cutter 14, and the winding is performed after leaving a slightly uncut portion in a circular shape with an annular cut portion being inserted, and thereafter, with an annular cut portion. It may be cut and used as the cap liner 2.

  As described above, in the present embodiment, the annular cavity 6 is formed on the liner sheet 3 by the injection mold 8 and the molten synthetic resin 7 is injection-molded in the cavity 6 to form the sealing layer 2b. The liner sheet 3 placed in the injection mold 8 by the sheet cutting mechanism 10 is cut into a disk shape with the same center outside the cavity 6, so that the liner sheet 3 that is continuous in a large or roll shape. It is not necessary to cut the disk into a disk shape in advance, and the injection molding of the sealing layer 2b and the cutting of the liner sheet 3 can be performed at the same time during the injection molding process by installing them in the injection mold 8 as they are.

  In addition, the sheet cutting mechanism 10 is provided on the fixed-side mold plate 4 so that the front end portion which is a sharp annular blade portion 14a can be opposed to the liner sheet 3, and the liner sheet 3 is cut by the blade portion 14a during mold clamping. Is provided with a cylindrical sheet cutter 14 that pushes the disk into a disk shape. When the mold is clamped, the blade portion 14a of the sheet cutter 14 is pressed against the liner sheet 3 to bring the disk-shaped sliding layer 2a into the injection molding position. It can be easily cut out in a state where it is positioned.

  The cap liner 2 produced in this manner is configured by bonding a sliding layer 2a, which is a hard resin sheet, and a flexible ring-shaped resin sealing layer 2b, and the flexible sealing layer 2b The hard resin sliding layer 2a is in contact with the inside of the cap shell in contact with the container opening. Moreover, since the sealing layer 2b of a flexible resin (mainly elastomer) that is expensive and has a high amount of elution is in a ring shape, the amount used can be reduced, and even when performing an elution test in a hygiene test, the elution amount can be reduced. Can be suppressed.

  In addition, the elastomer having a large amount of elution is formed as a ring-shaped sealing layer 2b, and the sliding layer 2a of hard resin is formed with a constant thickness on the top plate portion side of the cap. This is significantly less than In addition, the sliding layer 2a is superior in content resistance compared to the paint, and since the thickness is thick, there is no problem that the cap shell is put on the content and corroded by the content.

  Next, a cap liner manufacturing apparatus and method according to the present invention and a cap liner second embodiment will be described below with reference to FIGS. 5 and 6. Note that, in the following description of the embodiment, the same components described in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted. Further, in the cross-sectional views of FIGS. 5 and 6, the cross-section hatching is omitted.

  The difference between the second embodiment and the first embodiment is that, in the first embodiment, the sheet cutting mechanism 10 includes a cylindrical sheet cutter 14 provided on the stationary mold 4, whereas In the cap liner manufacturing apparatus according to the second embodiment, as shown in FIGS. 5 and 6, the sheet cutting mechanism 20 is set to the same outer diameter as the sliding layer 2 a and is used as a punch. A movable side mold plate 25 having a punching hole 25a through which a liner sheet 3 can be punched out in a disk shape by shearing between the fixed side mold plate 24 and a fixed side mold plate 24 to be pressed. It is a point that has been.

An injection mold 28 in the cap liner manufacturing apparatus according to the second embodiment includes a fixed-side mold plate 24 and a movable-side mold plate 25 facing each other, and a fixed-side mold plate attached to which the fixed-side mold plate 24 is attached. A plate 26 and a movable side mold plate mounting plate 27 to which the movable side mold plate 25 is attached are provided.
The fixed-side mold plate 24 has a circular convex portion 24a that is a punch portion that can be driven into the punching hole 25a on the surface facing the movable-side mold plate 25, and is clamped to the convex portion 24a. An annular groove portion 24b that forms the cavity 6 is formed, and a gate portion 23a is formed in the groove portion 24b.

In addition, the fixed-side template 24 has a manifold block 22 having a hot runner (not shown) inside, and a molten synthetic resin from the hot runner of the manifold block 22 is injected into the cavity 6 through the gate portion 23a. And a hot tip 29 as a next nozzle.
The movable side mold plate 25 is a core 25b that is slidable on the inner peripheral surface of the punching hole 25a, and a core that is incorporated in the movable side mold plate mounting plate 27 and biases the core 25b toward the fixed side mold plate 4 side. A spring 27a is provided.

  Next, a cap liner manufacturing method using the cap liner manufacturing apparatus of the second embodiment will be described with reference to FIG.

  First, after the liner sheet 3 is installed between the fixed side mold plate 24 and the movable side mold plate 25 as in the first embodiment, the mold is clamped by the fixed side mold plate 24 and the movable side mold plate 25. At this time, as shown in FIG. 6A, the convex portion 24a of the fixed-side mold plate 24 that is punched, and the movable-side mold plate 25 that is pressed into a die corresponding to the convex portion 24a (of the punching hole 25a) The liner sheet 3 is punched into a disk shape by shearing between the opening edge and the disk-shaped sliding layer 2a.

Further, the molten synthetic resin from the hot runner of the manifold block 22 is injected from the hot tip 29 into the cavity 6 through the gate portion 13a while the mold is clamped. Thereby, the annular sealing layer 2b is injection-molded on the cut disc-shaped sliding layer 2a.
Next, as shown in FIG. 6 (b), the fixed side mold plate 24 and the movable side mold plate 25 are separated from each other and opened to form an annular seal on the disc-shaped sliding layer 2a. The cap liner 2 on which the layer 2b is formed can be taken out.

As described above, in the second embodiment, the sheet cutting mechanism 20 is sheared between the fixed-side template 24 that is a punch and the fixed-side template 24 that is pressed and is a die corresponding to the fixed-side template 24. And the movable side mold plate 25 having a punching hole 25a through which the liner sheet 3 can be punched into a disk shape. Therefore, the disk-shaped sliding layer 2a can be obtained by punching at the same time as clamping. .
In the second embodiment, since the manifold block 22 having the hot runner and the hot tip 29 for injecting the molten synthetic resin into the cavity 6 are provided, the synthetic resin in the hot runner can be maintained in a molten state. It is excellent in continuous molding and high mass productivity can be obtained.

Next, the result evaluated by the Example which actually produced the liner for caps with the manufacturing apparatus and manufacturing method of the liner for caps concerning this invention is demonstrated concretely.
As an example of the present invention, a cap liner was manufactured as follows using the cap liner manufacturing apparatus of the first embodiment.

  First, several types (0.40 mm) of polypropylene sheets were prepared in a roll shape with a sheet molding machine and cut into a certain width to obtain a liner sheet. This liner sheet is introduced between a fixed mold plate and a movable mold plate set in an injection mold of a cap liner manufacturing apparatus, and is punched into a disk shape in the above-described process to form a sliding layer. At the same time, an elastomer was injected and bonded into a concentric ring shape on the disk-shaped sliding layer to form a sealing layer, thereby producing a cap liner.

  This cap liner was inserted into a PP (pill fur proof) cap shell made of aluminum having a nominal diameter of 38 mm and a thickness of 0.24 mm coated on the inner and outer surfaces. As the elastomer, TPS (styrene elastomer, PP (polypropylene), liquid paraffin and polymer SEPS blended) was used. At this time, this elastomer ring (sealing layer) is designed to contact the lip of the bottle mouth.

  In order to examine the characteristics of this cap, an aluminum bottle containing 275 g (total amount 338 ml) was filled with water and capped with a test cap. For capping, a single head capper was used. The pressure block used had a diameter of 35.6 mm and a drawing depth of 1.8 mm. The head pressure was capped at 1100N.

  Take 63 ml of head space, replace the head space with nitrogen gas at a constant gas pressure, capping and applying retort treatment at 121 ° C for 20 minutes, sealing performance immediately after retort, opening torque after standing at room temperature The value, drop impact performance, etc. were examined. In addition, after cooling the filled product, the cap was opened, and it was examined whether or not the cap liner was detached from the shell. These evaluation results are shown in Table 1 below.

In addition, as a comparative example, as a molded product outside the scope of the present invention, the results of a two-layer sheet of PP resin and TPS and a case of using a liner cap in-shell molded using the same TPS are also shown. It is shown in 1.
In addition, as an elution test based on the Ministry of Health and Welfare Notification No. 370 (Showa 34), 300 ml of normal hexane was filled in the same aluminum bottle, inverted and allowed to stand at 25 ° C. for 1 hour, and the amount of evaporation residue was also measured.

Note 1) For the sealing performance, the internal pressure before and after the retort was examined, and the presence or absence of leakage was examined based on the change.
Note 2) The drop impact performance is determined by capping, retorting, and standing for one day, then dropping the aluminum bottle upside down on an iron plate with a 10 ° angle vertically from a height of 30 cm, and the difference in internal pressure before and after the drop. And examined the number of leaks. Number of samples 10 each.
Note 3) Opening torque is the torque value at the start of rotation after standing at room temperature for 1 week after capping and heat treatment (first torque measured with a torque meter). The torque value was an average value of 10 samples.
Note 4) The elution amount was determined by measuring the amount of evaporation residue with n-heptane based on Ministry of Health and Welfare Notification No. 370 (Showa 34).

Note 1. As the PP, a PP sheet molded by a T-die extruder was used.
Note 2. TPS is a styrene elastomer and is a blend of PP, SEBS (styrene ethylene butylene styrene block copolymer) and liquid paraffin.
Note 3. The unit of thickness of the hard layer (sliding layer) and the soft layer (sealing layer) is mm. The in-shell mold type is obtained by molding only a soft layer (sealing layer). The shape of the seal part was the same.
Note 4. Slip-off property: ○ = When opening the disc (liner) does not come off the cap shell, Δ = When the disc is lifted but fits in the shell, × = The disc comes off the shell.
Note 5. Sealability: Indicates the number of leaks / number of samples immediately after retorting.
Note 6. Drop impact property: Shows the number of leaks / number of samples of the filled product dropped from an inverted height of 30 cm.
Note 7. Opening torque value: The first torque value after capping at room temperature for 4 weeks (the value at which the cap starts to move) is shown (unit: N · cm).
Note 8. Comprehensive evaluation
○ = Opening torque property, sealing property, drop impact resistance, and elution resistance good △ = Opening torque property, sealing property, drop impact resistance, good but poor elution resistance × = Open Inferior plug torque, drop impact resistance, and elution resistance

  As can be seen from Table 1 above, the ring mold liner (Example of the present invention) in which the hard layer (sliding layer) has a PP of 0.2 mm or more and the soft layer (sealing layer) is TPS is an example of comparison. Compared to the layer sheet liner and the TPS single liner using the in-shell mold method, the results show superior results in terms of openability and drop impact resistance. Also, in the ring mold liner (Example of the present invention), if the hard layer (sliding layer) is too thin as 0.1 mm, the evaluation of the slipping property tends to be Δ when opening, but it can be used as a cap. It was in range. Moreover, when the hard layer (sliding layer) was too thick as 0.9 mm, there was a drop impact resistance and one of the 10 cans leaked, but the result was that it could be used as a cap.

  The technical scope of the present invention is not limited to the above embodiments and examples, and various modifications can be made without departing from the spirit of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Manufacturing apparatus of cap liner, 2 ... Cap liner, 2a ... Sliding layer, 2b ... Sealing layer, 3 ... Liner sheet, 4, 24 ... Fixed side template, 5, 25 ... Movable side template, 6 ... cavity, 7 ... synthetic resin, 8, 28 ... injection mold, 9 ... injection unit, 10, 20 ... sheet cutting mechanism, 14 ... sheet cutter, 14a ... blade part, 25a ... punching hole

Claims (5)

A cap liner manufacturing apparatus comprising: a disk-shaped sliding layer; and an annular sealing layer that is laminated on the sliding layer and is a synthetic resin that is more flexible than the sliding layer,
A fixed-side mold plate on which the liner sheet serving as the sliding layer can be installed and a movable-side mold plate that can be separated from and attached to the fixed-side mold plate. An injection mold for forming an annular cavity on the liner sheet formed, and injection molding the melted synthetic resin to form the sealing layer;
An injection unit for injecting the synthetic resin melted in the injection mold;
A sheet cutting mechanism for cutting the liner sheet in a state of being installed in the injection mold into a disk shape with the same center outside the cavity, and manufacturing a cap liner apparatus. In the cap liner manufacturing apparatus according to claim 1,
The sheet cutting mechanism is provided on the fixed-side mold plate or the movable-side template so that a front end portion that is a sharp annular blade portion can be opposed to the liner sheet, and the blade portion at the time of mold clamping An apparatus for producing a liner for a cap, comprising a cylindrical sheet cutter that pushes the liner sheet into a disk shape. In the cap liner manufacturing apparatus according to claim 1,
The sheet cutting mechanism is set between the fixed side mold plate which is set to the same outer diameter as the sliding layer and is punched, and the fixed side mold plate which is pressed into a die corresponding to the fixed side mold plate. An apparatus for manufacturing a cap liner, comprising: the movable side plate having a punching hole capable of punching the liner sheet into a disk shape by shearing. A cap liner production method using the cap liner production apparatus according to any one of claims 1 to 3,
Installing a liner sheet serving as the sliding layer between the fixed side mold plate and the movable side mold plate;
A step of forming the sealing layer by injection molding the melted synthetic resin into the cavity formed on the installed liner sheet at the time of mold clamping;
A step of cutting the liner sheet installed in the injection mold by the sheet cutting mechanism into a disk shape with the same center outside the cavity. A method for producing a cap liner.   A cap liner produced by the method for producing a cap liner according to claim 4.

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