JP3697083B2 - Plastic container and method for manufacturing plastic container - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plastic container suitable for containing, for example, the contents of powder and granules or the contents of liquid, and a method for producing the plastic container.
[0002]
[Prior art]
A container that encloses a solid matter that dislikes moisture, such as powdered coffee, needs to be made of a material that does not allow moisture to pass through. For this reason, glass containers, metal cans or blow-molded plastic containers are usually used as this type of container.
Although glass containers and metal cans have characteristics such as moisture proofing and gas barrier properties and excellent storability, when the used containers are discarded, there are difficulties in the weight and volume of the containers themselves.
Although blow molded plastic containers can eliminate the weight and volume difficulties of glass containers and metal cans, the current blow molding technology reduces the thickness of plastic containers to 0.7 mm or less. Can not do it. Therefore, blow molded plastic containers are limited to co-extrusion molded products of a barrier substrate such as Eval and a synthetic resin material such as polyethylene and polypropylene in consideration of moisture resistance and gas barrier properties.
[0003]
In order to solve the problems of the plastic container, the present applicant applies an intermediate body made of a plastic laminate film to a mandrel as a mold core, and covers the upper and lower molds on the intermediate body. A method for manufacturing a plastic container in which a molten plastic resin material is injected into an upper die and a lower die by insert injection molding means, and an upper molded portion and a lower molded portion are integrally coupled to an outer surface of an intermediate body portion Developed.
[0004]
As shown in FIG. 6, the plastic container 1 made by the plastic container manufacturing method includes an intermediate barrel portion 2, an upper molded portion 3 integrally coupled to the upper end outer surface of the intermediate barrel portion 2, and an intermediate barrel. The lower molding part 4 integrally joined to the outer surface of the lower end of the part 2 and the lid member 5 for sealing the opening of the upper molding part 3 are configured.
[0005]
[Problems to be solved by the invention]
In the plastic container, since the intermediate body portion is formed of a plastic laminate film, it is possible to perform multicolor printing on the outer surface of the intermediate body portion, but a lower molding portion and an upper molding portion are provided on the outer surface of the intermediate body portion. Therefore, the printing effective area of the intermediate body portion is limited by the lower molding portion and the upper molding portion.
The manufacturing method of the plastic container, when the lower molding part is a bottomed molding part and the lower end of the intermediate body part is in contact with the bottomed molding part, by the injection pressure of the molten plastic resin material at the time of insert injection molding, Wrinkles may occur at the end of the intermediate body or the end of the intermediate body may turn up, resulting in a defective product.
[0006]
The present invention has been made in view of the above points, and the printing effective area of the body portion can be set wider than the conventional one, and wrinkles are generated at the end portion of the intermediate body portion during insert injection molding. It is an object of the present invention to provide a plastic container and a method for manufacturing the plastic container in which the end portion does not turn up.
[0007]
[Means for Solving the Problems]
A plastic container according to the present invention includes a barrel portion molded in a cylindrical shape with a plastic laminate film, a large-diameter molded portion having an upper end opening joined to an outer surface on one end side of the barrel portion by insert injection molding means, A bottomed small-diameter molded part joined to the inner surface of the other end side by insert injection molding means, and the large- diameter molded part is molded by a resin material injected from the side part of the large-diameter molding space, and the small-diameter molded part Is molded from a resin material injected from the bottom of the small-diameter molding space, and the large-diameter molded part has an inner diameter larger than the outer diameter of the small-diameter molded part .
[0008]
The method of manufacturing a plastic container according to the present invention provides a mold having a large-diameter molding space and a small-diameter molding space having an outer diameter smaller than the inner diameter of the large-diameter molding space, and a cylindrical body molded from a plastic laminate film. and, the tubular body portion is deposited on the outer surface of the mandrel serving as a mold core, the tubular positioned the tubular body to the inner portion of one end of the cylindrical body of the mandrel and deposited large-diameter type space Insert into the large-diameter molding space and small-diameter molding space from the side of the large-diameter molding space of the molding die and the bottom of the small-diameter molding space so that the other end of the body is located outside the small-diameter molding space. The molten plastic resin material is injected by injection molding means, and the large-diameter molded part is integrally coupled to the outer surface of one end of the cylindrical body, and the small-diameter molded part is integrally coupled to the inner surface of the other end of the cylindrical body. , of the upper end opening large-diameter Characterized in that to produce a plastic container having a small diameter forming part of the parts and a bottom.
[0009]
Embodiment
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows an example in which a plastic container according to the present invention is applied to a coffee container. The coffee container 10 includes a barrel portion 11 formed into a cylindrical shape with a plastic laminate film, and an outer surface on one end side of the barrel portion 11. The upper molding portion 12 is integrally molded with the lower molding portion 13 and is integrally molded with the inner surface of the other end side of the body portion 11.
[0010]
The upper molded part 12 is a cylindrical molded body having an inner diameter R1 and an upper end opening. A screw part 14 is formed at the upper part of the outer surface and a grip part 15 is formed at the lower part of the outer surface. A lid member is sealed at the upper end opening of the upper molding part 12, and a cap (not shown) is screwed onto the screw part 14 of the upper molding part 12.
[0011]
The lower molding portion 13 is a bottomed molded body having an outer diameter R 2, and the lower molding portion 13 has an outer diameter R 2 set smaller than an inner diameter R 1 of the upper molding portion 12.
[0012]
The body portion 11 is a cylindrical body having both ends opened by joining a material obtained by cutting a plastic laminate film into a rectangular shape and bonding the side ends to an envelope sticking die. It may be a cylindrical body with openings at both ends joined together and joined to a palm-attached mold, or a cylindrical body with openings at both ends in which side ends are overlapped with an envelope-attaching mold and the side ends are joined with tape from the inside.
[0013]
In consideration of moisture resistance and gas barrier properties, the above-mentioned plastic laminated film is laminated with a polyethylene film having a thickness of 70 microns, a polyester film having a thickness of 12 microns, an aluminum foil having a thickness of 12 microns, and a polyethylene film having a thickness of 70 microns. A laminate of cast polypropylene having a thickness of 70 microns, a polyester film having a thickness of 12 microns, an aluminum foil having a thickness of 12 microns and cast polypropylene having a thickness of 70 microns, and a cast polypropylene having a thickness of 70 microns. A laminate of a 12 micron thick polyester film and a 70 micron thick cast polypropylene is suitable.
If the aluminum foil is replaced with an ethylene vinyl alcohol copolymer film or a silica-deposited film, the body 11 becomes transparent while maintaining moisture resistance and gas barrier properties, so that the enclosed contents can be visually observed from the outside. it can.
[0014]
In the coffee container 10, when the body portion 11 is formed of a plastic laminate film containing aluminum foil, the body portion 11 is formed by joining the side ends of the material to a palm-attached mold, or overlapping the envelope-attached mold with side edges. The ones that are joined with tape from the inside are suitable. When the content is a liquid having a pH of 4 or less, such as a fruit juice drink, in order to prevent the aluminum foil from being oxidized and eluted into the liquid, as the body portion 11, the side edges of the material are enveloped. It is suitable to join the overlapping side ends with tape from the inside.
In the coffee container 10, when the body 11 is formed of a plastic laminate film that does not include an aluminum foil, as the body 11, so that the adhesive used when laminating does not melt into the contents, A material in which the side edges of the material are joined to a palm-attached mold or an envelope-molded mold in which the overlapping side edges are covered with tape from the inside is suitable.
[0015]
Below, the manufacturing method of the coffee container 10 is demonstrated.
The coffee container 10 is required to have moisture resistance and gas barrier properties because the encapsulated powder coffee dislikes changes in moisture and aroma. Therefore, a plastic laminate film having moisture resistance and gas barrier properties is selected for the body portion 11 constituting the coffee container 10.
[0018]
As shown in FIG. 2, the mold 20 for molding the coffee container 10 has a large-diameter molding space 21 and a small-diameter molding space 22 that are spaced apart from each other according to the dimensions of the body 11. The large diameter molding space 21 has an inner diameter larger than the outer diameter of the small diameter molding space 22. The large-diameter molding space 21 of the mold 20 corresponds to the shape of the upper molding portion 12 of the coffee container 10, and the small-diameter molding space 22 corresponds to the shape of the lower molding portion 13 of the coffee container 10. The lower molding part 13 molded by the small-diameter molding space 22. A bottomed cylindrical shape is provided so as to provide moisture resistance and gas barrier properties.
[0019]
First, the cylindrical body portion 11 is formed of a plastic laminate film having moisture resistance and gas barrier properties, and the formed body portion 11 is attached to the outer surface of a mandrel 23 serving as a mold core. In this case, if the trunk | drum 11 is circular in cross section, the circular thing corresponding to this will be used for the mandrel 23, and if the trunk | drum 11 is rectangular in cross section, the rectangular thing corresponding to this will be used.
[0020]
Next, as shown in FIG. 2, the mandrel 23 having the body 11 exterior is positioned at one end of the body 11 at the outer portion of the small-diameter molding space 22, and the other end of the body 11 is the large-diameter molding space 21. The mold 20 is mounted so as to be positioned at the inner portion. In this case, since the inner diameter of the large-diameter molding space 21 provided in the molding die 20 is larger than the outer diameter of the small-diameter molding space 22, the mandrel 23 that covers the body 11 is smoothly inserted into the molding die 20.
[0022]
When the setting of the mandrel 23 with the body 11 exterior to the molding die 20 is completed, insert injection into the small-diameter molding space 22 and the large-diameter molding space 21 of the molding die 20 through the runner 24 from the gate port 25 provided in the molding die 20. A synthetic resin material such as polyethylene resin is poured in a molten state by a molding means. In this case, as shown in FIG. 3, even when the lower end of the body portion 11 is in contact with the bottom of the small-diameter molding space 22, the injection pressure of the molten synthetic resin material at the time of insert injection molding acts in the direction indicated by the arrow. Therefore, wrinkles are not generated at the end of the body 11 due to the injection pressure of the molten synthetic resin material, and the end of the body 11 is not turned up.
By cooling the molten synthetic resin material injected into the large-diameter molding space 21 and the small-diameter molding space 22, the upper molding portion 12 is integrally coupled to one end outer surface of the trunk portion 11, and the other end inner surface of the trunk portion 11 is joined. A coffee container 10 in which the lower molding portion 13 is integrally coupled is molded.
[0023]
The mandrel 23 attached to the molding die 20 is pulled out after the coffee container 10 is molded. The inner diameter of the large-diameter molding space 21 provided in the molding die 20 is larger than the outer diameter of the small-diameter molding space 22. Therefore, the mandrel 23 can be easily pulled out without being obstructed by the upper molding portion 12.
[0024]
In the coffee container 10, the small-diameter molding portion 13 coupled to the lower end of the trunk portion 11 is located on the inner surface of the trunk portion 11, so that the effective printing area of the trunk portion 11 is widened only by the portion occupied by the small-diameter molding portion 13.
[0025]
In the above embodiment, the coffee container 10 is formed by integrally forming the upper molded portion 12 on the upper end outer surface of the barrel portion 11 formed into a cylindrical shape with a plastic laminate film, and integrally forming the lower molded portion 13 on the lower end inner surface. However, the upper molding portion 12 may be integrally molded on the inner surface of the upper end of the barrel portion 11 of the coffee container 10 by changing the arrangement of the mandrel 23 that covers the molding die 20 and the barrel portion 11. it can. In this case, the printing effective area of the trunk portion 11 of the coffee container 10 is widened only by the portion occupied by the small diameter molding portion 13 and the large diameter molding portion 12.
[0026]
4 and 5 show another embodiment of the present invention.
In the embodiment shown in FIG. 4, a suction line 31 is provided on the mandrel 30 with the body 11 exterior, and a laminate film 32 is adsorbed to the lower end of the mandrel 30, and the laminate film 32 is inserted into the small-diameter molding space 22. When a synthetic resin material such as polyethylene resin is injected in a molten state by the molding means, it is integrally bonded to the small diameter molded portion 13.
The laminate film 32 is a laminate of a polyethylene film having a thickness of 70 microns, a polyester film having a thickness of 12 microns, an aluminum foil having a thickness of 12 microns and a polyethylene film having a thickness of 70 microns, or a polyethylene film having a thickness of 70 microns. 12 micron thick polyester film, 15 micron thick Eval and 70 micron thick polyethylene film, 70 micron thick polyethylene film, 12 micron thick polyester film and 40 micron thick A laminate of aluminum foil and a polyethylene film having a thickness of 70 microns is suitable.
[0027]
In the embodiment shown in FIG. 5, a suction line 41 is provided in the mandrel 40 with the body 11 exterior, and a synthetic resin molded body 41 molded in advance is adsorbed to the lower end of the mandrel 40, and the synthetic resin molded body 41 is reduced in diameter. When a synthetic resin material such as polyethylene resin is injected in a molten state into the molding space 22 by insert injection molding means, it is integrally coupled to the small-diameter molding portion 13.
The synthetic resin molding 41 is formed by press-molding a laminate film obtained by laminating a polyethylene film having a thickness of 70 microns, a polyester film having a thickness of 12 microns, an aluminum foil having a thickness of 40 microns and a polyethylene film having a thickness of 70 microns. Made. Forming the synthetic resin molding 41 integrally with the small-diameter molding portion 13 of the plastic container is suitable when the plastic container is used as a container that dislikes the entry of oxygen.
[0028]
【The invention's effect】
As described above, the plastic container according to the present invention is provided with a molded part joined by insert injection molding means on at least one inner surface of a cylindrical part formed of a plastic laminate film, so that printing of the cylindrical part is effective. The area can be made wider than the conventional one.
The method for manufacturing a plastic container according to the present invention includes a molded part coupled to at least one inner surface of a barrel part formed of a plastic laminate film by insert injection molding means, and an inner diameter of a molded part located on the insertion side of the mandrel. By making the diameter larger than the outer diameter of the molding portion located on the opposite side, the mandrel can be easily pulled out from the molding die.
[Brief description of the drawings]
FIG. 1 is a front view showing, in cross section, a half of a plastic container made by a method of manufacturing a plastic container according to the present invention.
FIG. 2 is a schematic view showing a method for producing a plastic container according to the present invention.
FIG. 3 is a view showing a small-diameter molded portion in the method for producing a plastic container according to the present invention.
FIG. 4 is a view showing another embodiment of the method for producing a plastic container according to the present invention.
FIG. 5 is a view showing another embodiment of the method for producing a plastic container according to the present invention.
FIG. 6 is a perspective view showing a container made by a conventional container manufacturing method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Plastic container 11 Trunk part 12 Large diameter molding part 13 Small diameter molding part 20 Mold 21 Molding space 22 Molding space 23 Mandrel

Claims (3)

A barrel part molded into a cylindrical shape with a plastic laminate film, a large-diameter molded part with an upper end opening joined to an outer surface on one end side of the barrel part by insert injection molding means, and an insert injection on the inner surface on the other end side of the barrel part A small-diameter molded portion having a bottom and joined by molding means, the large-diameter molded portion is molded from a resin material injected from a side portion of the large-diameter molding space, and the small-diameter molded portion is a bottom portion of the small-diameter molding space. A plastic container, wherein the large-diameter molded part has a larger inner diameter than the outer diameter of the small-diameter molded part .   The plastic container according to claim 1, wherein a grip portion is provided on a lower portion of the outer surface of the large-diameter molded portion. Prepare a mold with a large-diameter molding space and a small-diameter molding space whose outer diameter is smaller than the inner diameter of the large-diameter molding space. Prepare a cylindrical body molded from plastic laminate film. The mandrel is attached to the outer surface of the mandrel as a core, and the mandrel with the cylindrical body is attached to one end of the cylindrical body and the other end of the cylindrical body is the small diameter forming space. Attached to the mold so that it is located on the outer side, molten plastic resin material is injected by insert injection molding means from the side of the large-diameter molding space and the bottom of the small-diameter molding space into the large-diameter molding space and small-diameter molding space. and, with integrally coupled to one end the outer surface of the cylindrical body a large circumference forming part, attached integrally to the small diameter forming portion at the other end the inner surface of the cylindrical body, closed large circumference forming part of the upper end opening Plastic with small diameter molding at the bottom Method of manufacturing a plastic container, characterized in that to produce the vessel.

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