JPH1110672A - Manufacture of packaging container, and packaging container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To wind a sheet only in a lower section by winding the sheet on a wall face under a female mold peripheral step of a cavity, bringing the upper end of the sheet into contact with a male mold peripheral step to push in the upper end into a cavity bottom and then flowing molten resin therein and bending and integrating a sheet upper edge along the male mold peripheral step. SOLUTION: A sheet 15 in the wound state is loaded on a wall face 19 under a cavity 17 of a female mold 16. When a male mold 22 is inserted into a cavity 17 of the female mold 16, an upper end 15a of the sheet 15 is pressed by a male peripheral step 21 of the male mold 22 to push the sheet 15 into a bottom 23 of the cavity 17. Then molten synthetic resin, for example, polypropylene resin is flowed from a runner 24 into a clearance S between the male mold 22 and and a cavity 17 of the female mold 16. Then the upper edge 15a of the sheet 15 is bent along a female mold peripheral step 18 by the resin flow pressure. Also the sheet 15 is bonded integrally with the polypropylene resin flowed in.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging container and a method for manufacturing the same, and more particularly to a packaging container having a peripheral step formed on a side wall so that various sheets can be surely formed integrally. The present invention relates to a container manufacturing method and a packaging container.

[0002]

2. Description of the Related Art Various packaging containers are filled with various liquid, cream or solid products such as foods and drinks, medicines and cosmetics, and are shipped from factories.
In order to provide a display of the trade name and the contents on the surface thereof, there are many sheets in which various sheets on which these are printed are integrally bonded.

[0003] These various sheets 15, that is, a sheet having a printed surface on a synthetic resin base material, a sheet having an aluminum base material deposited thereon, and further having a printed surface on an aluminum deposited surface, or an adhesive on the back surface A coating layer 5 such as a sheet provided with an agent is applied to the side wall 3 of the container 20, and in some cases, air permeability, water vapor permeability, and light transmittance are also improved. In many of these sheets, the sheet is integrally adhered to the outer surface of the packaging container by a so-called in-mold molding method.

[0004]

However, in the above-described conventional method, the wound printing sheet or the aluminum vapor-deposited sheet is placed in a cavity and integrated at the time of injection molding. When set in a wound state on the wall surface of the mold, the sheet returns to its original shape by spring action and opens, so when inserting the male mold into the female mold having a cavity, The sheet was being pressed into the cashew.

Therefore, in this method, the sheet needs to have a height reaching the upper surface from the bottom surface of the mold. Therefore, the sheet covering the entire vertical direction of the side wall 3 of the packaging container 20, that is, the covering layer 5 is formed. And it was impossible to bond the sheet to only a part of the sheet in the vertical direction.

However, for design and other reasons, there are cases where it is desired to adhere a sheet to only a part of the packaging container in the circumferential direction. In this case, the conventional in-mold molding method cannot be adopted, and the work of separately attaching the sheets is required, so that there is a disadvantage that the production efficiency is very poor.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a conventional problem. A packaging container in which a sheet is integrally wound only on a lower portion without covering an upper portion of the packaging container. And a container therefor.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a packaging container and a method for manufacturing the same, and is configured as follows to solve the above-mentioned technical problems. That is, claim 1
The method for manufacturing a packaging container described in (1) has a cavity provided with a female peripheral step corresponding to the peripheral step in order to form a truncated conical packaging container having a peripheral step formed on a side wall. Using a female mold and a male mold having an outer shape corresponding to the cavity and providing a male peripheral step corresponding to the female peripheral step, first, the female mold of the cavity of the female mold The sheet is loaded on the wall surface below the peripheral step in a wound state, and then the male mold is inserted into the cavity of the female mold while the upper end of the sheet abuts on the male peripheral step. After pushing this sheet up to the bottom of the cavity, molten synthetic resin is poured into the gap between the cavity of the female mold and the outer surface of the male mold from the runner, and the upper edge of the sheet is moved along the peripheral step of the female mold. And bend the package container in-mold with the sheet. And wherein the door.

In the cavity of the female mold, the sheet is pushed down to the bottom of the cavity. Next, a thermoplastic synthetic resin is press-fitted from a runner. Then, the upper edge of the sheet is bent outward along the female peripheral step, and comes into contact with the wall surface of the packaging container. Thus, the sheet is integrally adhered to the packaging container.

Hereinafter, important components of the present invention will be described. (Female peripheral step) The position of the female peripheral step is almost the same as the height of the sheet, and it is desirable that the upper end of the sheet is in contact with the female peripheral step.

In the cavity of the female mold, the upper edge of the sheet is pressed by the male peripheral step to prevent the sheet from returning to its original shape by the action of the spring. In this case, when the gap between the cavity of the female mold and the outer surface of the male mold, that is, the thickness of the container of the main body is t and the width of the male mold step is Z, Z is set to about 1.5 t. It is desirable. When Z ≦ t, when inserting the sheet into the cavity, it is impossible to make the upper end of the sheet come into contact with the male peripheral step. (Synthetic resin) This container can be manufactured using a thermoplastic resin such as a polypropylene resin or a polystyrene resin.

As described above, according to the method for manufacturing a packaging container according to the first aspect, a packaging container in which a sheet is adhered only to a lower portion of the packaging container can be obtained. This packaging container has a frusto-conical shape with a peripheral step on the side wall of the container body, a sheet adhered to a part of the side wall with the peripheral step as a boundary, and a top opening at the top. The slope of the side wall is in the range of 4 to 10 degrees.

The important components of the invention of the packaging container will be described in detail. (Sheet) The sheet is preferably formed in a sheet shape by biaxially stretching a base material of a synthetic resin. That is, a sheet is cut and used according to a predetermined shape and size according to the shape of the packaging container. In addition, the material and use conditions of the packaging container, such as those on which the surface of the substrate is printed, those on which aluminum is deposited, those on which the aluminum is deposited, or those on which various adhesives are provided on the back surface Various items can be prepared according to the conditions. As an adhesive,
Ethylene vinyl acetate and acrylic adhesives are preferred.

In addition, when the packaging container is made of a compatible synthetic resin, such as polypropylene resin or polystyrene resin, if the sheet is made of the same material, both sheets adhere to each other during molding. Needless to say, no adhesive is required.

(Stacking Peripheral Step and Side Wall) The stacking peripheral step is preferably provided at a position of about 2/3 to 1/3 of the total height of the main body, particularly at a position of about half. Then, the upper side wall on the mouth side of the container and the lower side wall on the bottom side are formed from the peripheral step, and the inclination of the upper side wall and the lower side wall can be formed at different angles. The slope of the side wall is set to 5 to 10 degrees, preferably 5 to 8 degrees. If the inclination angle is small, the fitting state of the stacked packaging containers is so tight that it becomes difficult to take out one by one, so the above range was selected. In this case, it is preferable to make the slope of the lower side wall larger than the slope of the upper side wall. However, this point is not the gist of the present invention but belongs to the selection items.

A second feature is that an upper edge of the sheet is bent and attached to a lower edge of the stacking peripheral step portion. A third feature is that the width of the lower edge of the stacking peripheral step is at least 1.5 times or more the thickness of the container.

According to the packaging container of the present invention, when these are stacked by the stack ribs, the stacking peripheral steps are engaged with each other so that the stacking can be stably performed, and the separation can be easily performed one by one. is there. Therefore, at the time of filling the contents or the like, these packaging containers can be easily separated.

Further, the sheet attached to the side wall from the stacking peripheral step to the bottom does not peel off because it is firmly attached. For this reason, the printed trademark, description of the contents, etc. are always clearly displayed on the packaging container.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a packaging container according to the present invention. First, an embodiment of an injection molding method for producing a packaging container according to the present invention will be described in detail with reference to FIGS.

As shown in FIG. 1, this packaging container has a stacking step 11 of a frusto-conical body 10 formed thereon. A female die 16 having a female peripheral step 18 corresponding to the stacking step 11 in a cavity 17, and a male die having an outer shape corresponding to the cavity 17 and corresponding to the female peripheral step 18. A male mold 22 having a mold peripheral step 21 is prepared.

FIGS. 5 to 6 show the method of the present embodiment over time. First, as shown in FIG. 4, a sheet 15 serving as a coating layer 5 on which aluminum is deposited is wound. Then, as shown in FIG. 5, the above-described sheet 15 is loaded in a wound state on the wall surface 19 below the cavity 17 of the female mold 16. Although the angle of the wall surface 19 of the female mold 16 is set to 8 degrees, when the angle is set to 8 degrees or more, the wound sheet 15 becomes easy to spread, and it becomes difficult to maintain the wound state. .

Next, as shown in FIG.
2 is inserted into the cavity 17 of the female mold 16. Then, the male peripheral step 21 of the male mold 22 is moved to the upper edge 15 of the sheet 15.
a, the sheet 15 is pushed down to the bottom 23 of the cavity 17.

Next, the molten polypropylene resin is poured from the runner 24 into the gap S between the male mold 22 and the cavity 17 of the female mold 16. Then, the upper edge 15a of the sheet 15
Is bent along the female peripheral step 18 by the flow pressure of the resin. Further, the sheet 15 is integrally bonded to the flowing polypropylene resin.

Thereafter, when the male mold 22 is pulled out of the cavity 17 and the molded product is taken out, a packaging container as shown in FIG. 1 or 2 is obtained. In this packaging container, the sheet 15 is formed integrally with the main body to form the coating layer 5, and at the same time, the bent upper edge of the sheet 15 becomes the upper edge 14 of the coating layer 5 as is clear from FIG. Thus, a more solid integral molding of the coating layer 5 is realized.

According to the manufacturing method of the packaging container of the embodiment of the present invention, since the angle of the wall surface 19 of the female mold 16 is set to 8 degrees, it is possible to surely prevent the sheet from returning to the original shape by the action of the spring. it can.

Also, since the upper edge of the sheet is bent outward along the female peripheral step, the sheet is formed integrally with the wall surface of the packaging container, and the bent portion also has the lower edge of the flange portion. Therefore, the sheet can be firmly attached.

Next, the packaging container manufactured by the above method will be described. 1 is packaging container according to an embodiment of the present invention is shown at 20 _1. FIG. 2 shows a packaging container 2 according to another embodiment of the present invention.
It is shown in 0 _2. FIG. 3 is a cross-sectional view of a half portion of the container showing a state in which the packaging containers according to the present invention are stacked.

The packaging container of the embodiment shown in FIG. 1 20 ₁
Has a frusto-conical body 10 made of polypropylene resin, a flange 2 is provided at an opening 1 of the body 10, and a laminate sheet 6 is provided on an upper surface of the flange 2.
To form the lid 7.

Further, a sheet 15 integrally bonded by the above-described method is provided on the entire surface of the lower side wall 3b of the container, that is, the surface extending from the flat bottom portion 8 to the lower end surface 9 of the main body 10.

The sheet 15 was prepared by coating aluminum on a base material by vapor deposition or the like, by a synthetic resin having a printed surface, by printing on an aluminum-deposited surface, or by applying an adhesive to the back surface. And is integrally adhered to the main body 10 as the coating layer 5.
As shown in FIG. 9, the upper edge 14 of the sheet 15 serving as the coating layer 5
Is bent outward, is formed integrally with the stacking peripheral step portion 11 of the main body 10, and is firmly joined so that the coating layer 5 does not peel off. In the present embodiment, the main body 10
Thickness t ₁ of the upper side wall 3a of the wall thickness t ₂ of the lower side wall 3b, when the thickness of the product duty peripheral stepped portion 11 of t, also the width is Z,
t ₂ ≦ t ₁ , where t has a thickness close to t ₁ . Also, Z = 1.5t.

On the other hand, a stacking peripheral step portion 11 is formed at substantially half the position of the main body 10, and is divided into an upper side wall 3a above the stacking peripheral step portion 11 and a lower lower side wall 3b below. The slope α of the upper side wall 3a is formed smaller than the slope β of the lower side wall 3b.

Further, the flange portion 2 and the side wall 3 of the main body 10
At a pitch of 5 to 10 mm and a height h of 3 to
A plurality of stack ribs 4 each having a square shape in a front view of 4 mm are provided to improve the strength of the flange portion 2 and the side wall. Further, when stacking the packaging container 20b of the same type as shown in FIG. 3 above the packing container 20 ₁ shown in FIG. 1, the upper edge 12 of the packaging containers 20 ₁ product duty peripheral stepped portion 11, the other the lower edge 13 of the packaging containers 20 ₁ product duty peripheral stepped portion 11 is engaged with exist mutually slight gap (for example, about 0.3 mm).

According to such a packaging container, the sheet adhered to the side surface from the peripheral portion for stacking to the bottom portion is firmly adhered, and the trademark or description of the content printed on the sheet 15 is always printed on the packaging container. It is clearly displayed.

Further, in the case where foodstuffs are filled in the packaging containers 20 ₁ and 20 ₂ , if an aluminum vapor-deposited sheet is integrally formed on the entire surface up to the bottom portion 18, even if it is heated by a microwave oven as it is, the inside of the containers can be kept. The temperature difference from the peripheral part is eliminated. Therefore, since the contents are heated uniformly, it exhibits excellent features as a food packaging container.

The packaging containers 20 ₂ according to the second embodiment shown in FIG. 2, those having substantially the same shape as the packing container 20 ₁ shown in FIG. 1 except for the following points. That is, the side wall 3 of the main body 10 has the same gradient angle β between the upper side wall 3a and the lower side wall 3b, the bottom 8 is raised on the center side, and the stack rib 4 is substantially triangular in front view. That is what they do.

In the packaging container according to the above-described embodiment, when the packaging containers are stacked, the stacking peripheral steps are engaged with each other to perform the stacking.

[0037]

As described above, according to the method for manufacturing a packaging container of the present invention, the upper edge of the sheet is pressed by the male peripheral step in the cavity of the female mold, so that the sheet can be securely held. Since it is pushed down to the bottom of the mold, stable setting is possible, and a packaging container in which the sheet is integrally wound only on the lower part of the container can be easily obtained.

Further, even if there is a stack rib, the sheet stuck to the side wall from the peripheral portion for stacking to the bottom can be firmly stuck without being obstructed by the stack rib, and the sheet is printed without peeling. Trademarks and descriptions are always clearly displayed on the packaging container.

[Brief description of the drawings]

FIG. 1 is a partially cut-away side view of a packaging container according to an embodiment of the present invention.

FIG. 2 is a partially cut-away side view of a packaging container according to a second embodiment of the present invention.

FIG. 3 is a partially cutaway view showing a stacked state of the packaging containers of the present invention.

FIG. 4 is a perspective view of a sheet in a wound state before being loaded into a mold.

FIG. 5 is a partial cutaway view of a female mold having a sheet mounted thereon, showing an initial step of the method for manufacturing a packaging container according to the present invention.

FIG. 6 is a partial cross-sectional view of the mold after the male mold has been inserted into the female mold, showing the next step of the method for manufacturing a packaging container of the present invention.

FIG. 7 is a partially enlarged sectional view of a main part of the packaging container of the present invention.

FIG. 8 is a partial sectional view of a conventional packaging container.

FIG. 9 is a partial sectional view of another conventional packaging container.

FIG. 10 is a partial cross-sectional view of yet another conventional packaging container.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Mouth part 2 Flange part 3 Side wall 3a Upper side wall 3b Lower side wall 4 Stack rib 5 Coating layer 6 Lid (laminated sheet) 8 Bottom part of packaging container 10 Main body 11 Stacking peripheral step 12 Upper edge of stacking peripheral step 13 Lower edge of stacking peripheral step 14 Upper edge of coating layer 15 Sheet 15a Upper edge of sheet 16 Female mold 17 Cavity 18 Female peripheral step 19 Wall surface below female peripheral step 20, 20 ₁ , 20 ₂ Packaging Container 21 Male Step 22 Male Die 23 Bottom of Cavity 24 Runner

Claims (3)

[Claims] 1. A female mold having a cavity provided with a female peripheral step corresponding to the peripheral step to form a frusto-conical packaging container having a peripheral step formed on a side wall; A male mold having an outer shape corresponding to the cavity, and a male mold provided with a male mold corresponding to the female mold, first, a lower portion of the cavity of the female mold than the female mold. The wall is loaded with the sheet in a wound state, and then the male mold is inserted into the cavity of the female mold, and the sheet is brought to the bottom of the cavity while the upper end of the sheet is in contact with the male mold step. After pushing in, the molten synthetic resin is poured into the gap between the cavity of the female mold and the outer surface of the male mold from the runner, and the upper edge of the sheet is bent along the peripheral step of the female mold, and the packaging is performed. Characterized in that a container for use is molded in-mold with the sheet. Method for manufacturing containers for packaging. 2. A container obtained by the method for manufacturing a packaging container according to claim 1, comprising a peripheral step on a side wall of the container body, and a sheet on a part of the side wall with the peripheral step as a boundary. A packaging container characterized in that it is a frusto-conical shape which is glued and has an opening at an upper surface, and a slope of said side wall is in a range of 4 to 10 degrees. 3. The packaging container according to claim 1, wherein the width of the step of the peripheral step is at least 1.5 times or more the thickness of the container.