JP4747556B2 - Lid and manufacturing method thereof - Google Patents

Description

Field of Invention

  The present invention relates to a lid member attached to the mouth of a container body, and more particularly to a lid member formed by in-mold injection molding and having a label on the upper surface.

  As a lid used for a container such as food, a lid that is detachably attached to the mouth of the container body is used. This lid member usually has a structure in which a fixing ring part engaged and fixed to a container body and an upper lid part that can be freely opened and closed are connected via a hinge (Patent Document 1, etc.). In such a lid member, in order to display the contents of the container, a label may be attached to the upper plate surface of the lid member in addition to the side surface portion of the container body.

Conventionally, lid materials having such a label have been manufactured by molding a lid material by injection molding or the like and then sticking the label on the upper surface of the lid material using an adhesive or the like.
Japanese Patent Laid-Open No. 11-43168

  However, the conventional lid material has a problem that wrinkles occur on the label provided on the upper surface of the lid when the lid is opened and closed. That is, the lid is opened and closed by fixing the container body by hand and pulling up a rib (knob) provided at one end of the upper lid with the hinge as a fulcrum. At this time, the lid member is subjected to a force that causes the upper lid to bend. Usually, since the lid material is formed of a flexible thermoplastic resin such as polyolefin, the upper lid is curved when the lid is opened and closed. When a label is attached to the upper lid surface using an adhesive or the like, wrinkles may occur on the label due to the curvature of the upper lid.

  In addition to the occurrence of wrinkles, there is a problem that the label peels off when the lid is repeatedly opened and closed.

Furthermore, since the label itself has a certain thickness, a step is generated at the peripheral end portion of the label attached to the upper plate surface of the lid member. Dust or the like may adhere to the stepped portion and contaminate the vicinity of the end of the label, which may be a sanitary problem, particularly in a container used for food.
The present invention has been made in view of the above problems, and the object of the present invention is to attach a lid material to a container body and use it even when the top lid is repeatedly opened and closed. It is an object of the present invention to provide a lid member in which the label does not occur and the label itself is not peeled off from the upper lid.

  The lid material according to the present invention has an in-mold label, is formed by in-mold injection molding, and is detachably attached to the mouth of the container body. And an openable / closable upper lid having a top plate having a side plate descending from a peripheral line of the top plate, and engaging with the side plate via a tear ring and a hinge, A fixing ring, and the upper plate is formed in a convex shape so that the surface on the in-mold label side protrudes outward.

  In addition, a method for manufacturing a lid material according to another aspect of the present invention includes a step of mounting an in-mold label on an outer mold side in a mold composed of an outer mold and an inner mold, and an inner mold side. A process of extruding a resin from an injection hole into a mold and performing injection molding.

  According to the lid material of the present invention, when the lid material is attached to the container body and used, the label provided on the lid plate is stuck by in-mold molding even when the upper lid is repeatedly opened and closed. Therefore, no wrinkle is generated on the label, and the label itself is not peeled off from the upper lid.

  Furthermore, since the lid member is formed by in-mold molding, no step is generated at the label peripheral end portion of the upper plate, so that dust or the like hardly adheres near the label peripheral end portion. Moreover, according to the lid | cover material by this invention, since the label is stuck without using an adhesive agent etc., an adhesive agent etc. do not adhere to the lid | cover upper board surface.

  Furthermore, according to the lid material of the present invention, since the upper plate is formed in a convex shape so that the surface on the in-mold label side protrudes outward, the lid material is a flexible thermoplastic resin such as polyolefin. Even if it is formed, etc., since the rigidity of the lid material is improved, the upper plate is difficult to bend when the lid is opened and closed.

  Moreover, according to the manufacturing method of the lid material of the present invention, the upper plate is placed on the in-mold label side by introducing the injection resin from the mold side opposite to the mold on the side where the in-mold label is provided. It can be easily formed in a convex shape so that the surface protrudes outward.

  Hereinafter, a lid material and a method for producing the lid material according to the present invention will be described with reference to the drawings.

1. Lid Figure 1 shows a side view of the lid according to the invention. Moreover, FIG. 2 shows the AA cross section of the lid | cover material shown in FIG.

  The lid member 1 includes an upper lid 2 that can be freely opened and closed, and a fixing ring 3 that engages with the mouth of the container body. The upper lid 2 includes an upper plate 4 having an in-mold label arranged on the outer surface, and a side plate 5 that descends from the peripheral line of the upper plate 4. The upper lid 2 is connected to the fixing ring 3 via a tear ring 6 and a hinge 7.

  Usually, the lid | cover material 1 of this invention is used in combination with the container main body which has a mouth part. In the initial state where the lid member is combined with the container body, the upper lid 2 cannot be opened or closed because the upper lid 2 is connected to the fixing ring 3 via the tear ring 6. In this state, when the user grasps and pulls the tear piece 8, the tear ring 6 that has connected the upper lid 2 and the fixing ring 3 is torn circumferentially, and the upper lid 2 and the fixing ring 3 are separated.

  Although this tearing ring 6 may be provided so as to make one round in a circumferential shape, as shown in FIG. 3, it is provided only in a part of the cover member 1 in the circumferential direction, and a cut line is provided in the remaining part. A bridge 9 may be provided. After the tear ring 6 is torn around the circumference, when the upper lid 2 is further pulled up with the rib 10, the bridge 9 is broken along the cut line by the tensile force at that time, and the upper lid 2 is centered on the hinge 7. It swings to the open state shown in FIG. Thus, since it is necessary to break the tear ring and the bridge when the lid is first opened, the user can recognize that the container has not been opened. The user can also determine whether the container is in an unopened state or an already opened state based on the presence or absence of a tear ring.

  As shown in FIG. 2, the upper lid 2 includes an upper plate 4 to which an in-mold label 11 is attached. As will be described below, the lid material of the present invention is formed by in-mold injection molding, and the label and the lid material are integrally molded. By manufacturing the lid material by such a molding method, no step is generated at the peripheral edge 12 of the label on the upper plate surface 4 of the upper lid 2. In-mold injection molding means that a label having a heat seal layer on one side is set in advance on the mold during injection molding, and the heat seal layer of the label is formed on the surface of the molded product by the heat of the resin during molding. This is a molding method in which labeling is performed at the same time as molding by fusing.

  The upper plate 4 is formed in a convex shape so that the surface on the in-mold label 11 side protrudes outward. The user opens and closes the lid by pulling up the upper lid 2 while holding the rib 10. Usually, the rib 10 is pulled up while supporting the upper plate 4 with a finger to stably open and close the lid. At this time, the label surface of the upper plate 4 is pressed with a finger. Since the upper plate 4 is formed in a convex shape in the lid material of the present invention, the force exerted on the upper plate is dispersed throughout the upper plate. By such an action, even when the upper plate is pressed with a finger, deformation of the upper plate is suppressed.

  Next, the state which combined the cover material and container main body by this invention is demonstrated.

  FIG. 5 is a cross-sectional view of the state in which the lid 1 is mounted on the container body 20. The fixing ring 3 of the lid 1 is fixed by engaging with the mouth portion 21 of the container body 20. With this fixing ring 3, the lid member 1 can be attached to and detached from the container body 20.

  The upper plate 4 is provided with an inner ring 13 so as to be disposed inside the side plate 5 together with the side plate 5 descending from the peripheral line of the upper plate 4. When the mouth 21 of the container body is press-fitted into the gap between the side plate 5 and the inner ring 13, the upper lid is closed. Since there is almost no gap between the mouth portion 21 and the side plate 5 or the inner ring 13, the hermeticity of the container is maintained.

  By the way, according to the configuration as described above, when the lid is closed, the tip of the mouth portion 21 of the container body may not enter the space between the side plate 5 and the inner ring 13 and may fall to the outer diameter side. is expected. On the other hand, in the present invention, the height of the inner ring is set such that the tip of the inner ring 13 on the hinge 7 side is in contact with the tip of the mouth portion 21 of the container body with the upper lid opened. Is adjusted. Therefore, when the upper lid is closed, the tip of the inner ring 13 slides on the upper edge of the mouth portion 21 and is guided between the side plate 5 and the inner ring 13, so that the inner ring is surely moved to the inner diameter side of the container. Can be fitted.

  Further, as shown in FIG. 5, the inner ring 13 is low on the side where the rib 10 is provided and is high on the side where the hinge 7 is provided. Thus, by closing the rib-side inner ring lower than the hinge-side inner ring, when closing the lid, the upper lid gradually engages with the mouth of the container body. The inner ring on the rib side does not interfere with the mouth of the container body.

  Further, the upper plate 4 of the lid member 1 is provided with a contact ring 14 that descends from the peripheral line of the upper plate 4 between the side plate 5 and the inner ring 13. The contact ring 14 contacts the upper end of the mouth portion 21 of the container body when the lid member 1 is engaged and fixed to the container body 20. This contact ring further improves the sealing performance of the container.

  The lid material of the present invention is not particularly limited as long as it is a thermoplastic resin capable of in-mold injection molding, and various resins can be used. Among these thermoplastic resins, polyolefin resins such as polyethylene and polypropylene are preferably used. In particular, a linear low density polyethylene resin or a crystalline polyethylene resin is preferably used in the present invention.

  From the viewpoint of tearability of the tear ring 6 and the bridge 9, a linear low density polyethylene resin can be preferably used.

  The in-mold label used in the present invention preferably has a heat seal layer on one side thereof. As the heat seal layer, a biaxially stretched polypropylene film (hereinafter referred to as OPP film) subjected to a heat seal treatment can be suitably used. In addition, the in-mold label preferably has a multilayer structure in order to exhibit various functions. In the case of a multilayer structure, it is preferable to use the same material as the heat seal layer as the layer provided on the surface opposite to the heat seal layer. For example, when the heat seal layer is OPP, the opposite layer is preferably OPP. In this way, by using the same material, it is possible to prevent the label from curling, so that wrinkles and label peeling can be effectively suppressed.

  Multi-layer structure includes heat seal layer / OPP two-layer structure, heat seal layer / aluminum foil / OPP three-layer structure, heat seal layer / polyethylene terephthalate (PET) film / aluminum foil / OPP The four-layer structure can be used. In addition, the OPP film which has heat sealability can be used conveniently for the said heat seal layer. Moreover, what provided the hologram printing etc. to the OPP layer and PET layer as an intermediate | middle layer provided between a heat seal layer and an OPP layer, etc. can be used.

2. Manufacturing method of lid material The lid material of the present invention is manufactured by in-mold injection molding. In the in-mold injection molding process, the in-mold label is mounted on the outer mold side of the mold composed of the outer mold and the inner mold, and the injection hole provided on the inner mold side enters the mold. A process of extruding resin and performing injection molding. The injection hole is preferably provided so that the injection resin is introduced near the center of the inner mold, that is, near the center of the in-mold label. Since the resin spreads from the vicinity of the center of the label and spreads in the mold, the peripheral edge portion of the label is embedded in the resin, so that it is difficult for a step to be formed on the upper plate of the lid.

  According to the manufacturing method of the present invention, in-mold injection molding is performed by attaching an in-mold label to a predetermined position of the outer mold and extruding the injection resin from the inner mold on the opposite side. There is a difference in the speed at which the resin hardens on the outside. That is, since the temperature in the mold on the side (outside) where the label is attached is lower than that in the inner mold, the injection resin is cooled and solidified faster on the outer side of the mold. The difference in shrinkage stress is caused by the resin solidification rate being different between the inner mold side and the outer mold side of the lid. As a result, as shown in FIG. 2, the upper plate is formed in a convex shape so as to protrude outward on the side where the in-mold label is attached. In particular, when high crystallinity polypropylene or high-density polyethylene is used as the injection resin, the faster the solidification rate, the slower the crystallization rate. Have different crystallinity. Due to such a difference in the crystallization speed, there is a difference in shrinkage stress between the inner mold side and the outer mold side of the lid member, and the tendency to protrude more outward becomes stronger.

  Further, in consideration of the balance between the tearability of the tearing ring or bridge of the lid material and the crystallinity of the resin, a linear low density polyethylene resin is more preferably used as the injection resin.

1 is a side view of a lid material according to the present invention. The AA cross section of the cover material shown in FIG. 1 is shown. The side view of the cover material by the other aspect of this invention is shown. The perspective view of the state which combined the cover material and container main body by this invention is shown. 1 is a cross-sectional view of a state in which a lid according to the present invention and a container body are combined.

Explanation of symbols

1. Cover material 2. Upper lid 3. Fixing ring 4. Upper plate 5. Side plate 6. 6. Tear ring Hinge 8. Tear pieces 9. Bridge 10. Rib 11. 11. In-mold label Label peripheral edge 13. Inner ring 14. Contact ring 20. Container body 21. Mouth

Claims (9)

In the lid material that has an in-mold label and is molded by in-mold injection molding, and is detachably attached to the mouth of the container body.
The lid is made of polypropylene resin or polyethylene resin,
An upper plate having an in-mold label disposed on an outer surface, a side plate descending from a peripheral line of the upper plate , and an openable lid that includes an inner ring disposed on the inner side of the side plate ;
A fixing ring that is connected to the side plate via a tear ring and a hinge and engages with the mouth of the container body;
The lid of the container body is detachably attached to the mouth of the container body by being press-fitted into the gap between the side plate and the inner ring,
The said upper board is formed in convex shape so that the surface by the side of the label for in-molds may protrude outward, The lid | cover material characterized by the above-mentioned.   The lid material according to claim 1, wherein the in-mold label includes a heat seal layer. The lid material according to claim 1 , wherein the polyethylene resin is linear low-density polyethylene. The polyethylene resin is a crystalline polyethylene lid material according to claim 1. A method for producing the lid member according to any one of claims 1 to 4 ,
Attaching the in-mold label to the outer mold side in the mold composed of the outer mold and the inner mold;
And a step of performing injection molding by injecting resin into the mold from an injection hole provided on the inner mold side. The method according to claim 4 , wherein the injection hole is provided at a position where the resin is injected near the center of the in-mold label. The method according to claim 5 or 6 , wherein the injection resin is made of polypropylene resin or polyethylene resin. The method of claim 7 , wherein the polyethylene resin is linear low density polyethylene. The method according to claim 7 , wherein the polyethylene resin is crystalline polyethylene.

Images