JP4379770B2 - Molding method and molding device for container in which sticking body is molded in-mold - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The invention of the present application is a container in which a label such as a printed thin paper or a film, which has been used in the past, is adhered to an outer peripheral surface of a body wall portion of various synthetic resin containers by in-mold molding. This method is related to the in-mold molding method. In particular, when the above-mentioned adhesive body is mounted in the cavity of an injection mold, and the molten thermoplastic synthetic resin is injected into the cavity and molded. to, molding or me wound is adherend bonded thin the by molten resin flow, and be injection molded so as not to move, the containers in-mold molded is clean vessel surface該貼adhesive member And a molding die .
[0002]
[Prior art]
Conventionally, various stickers have been provided on the outer wall surfaces of various containers to bring about decorative effects, display product names and contents, or display various precautions for use, etc. The direct printing method that prints directly on the surface of the container, the sticking method that pastes printed thin paper or film with glue etc., the film shrink method that heats and shrinks by placing the printed heat shrinkable film on the container, etc. Among them, the gluing method is often used because it has an advantage that it can be easily applied to containers having various shapes.
[0003]
And in order to apply the above-mentioned pasting method to a container made of synthetic resin, after taking out the container molded by injection molding etc. from the mold, the pasted body that has been glued in advance on the back surface of the label or the like by hand The method of sticking on the outer wall surface of a container or sticking a sticking body using a special sticking machine is taken.
However, even if any of these manual or mechanical sticking methods is adopted, it is necessary to paste the label on the back side of the sticking body before sticking to the container surface. However, there is a problem that it becomes somewhat complicated.
[0004]
Therefore, in the method of sticking a label or the like on a synthetic resin container, as one of the methods for eliminating the above complexity, a sticking body is mounted in a mold for molding the container in advance. Then, a so-called in-mold molding or insert molding method is employed in which a label is attached to the surface of a container that is molded simultaneously with the molding of the container by performing blow molding or injection molding.
[0005]
As a general method for molding various containers using a thermoplastic synthetic resin, a blow molding method of biaxially stretching a parison in a soft state is suitable for molding a bottle-shaped hollow container. On the other hand, in order to mold wide-mouthed containers and other containers that are not limited to bottles and are suitable for containing and sealing food and other contents, molten resin is used to mold mold cavities. An injection molding method in which it is injected and molded inside is suitable.
[0006]
When in-mold molding or the like is applied to the blow molding of the hollow container described above, there is no fear that wrinkles or the like will occur on the in-mold molded sticking body, and the appearance of the container will not be deteriorated. When in-mold molding is applied to molding and a container as shown in FIG. 3 is molded, the sticking body to be molded in-mold moves and shifts in position or becomes a bowl shape. May cause inconvenience.
Therefore, the sticking body is adsorbed and fixed to the inner surface of the molding die so that the sticking body does not shift or become a bowl shape in this way, and the sticking body is attached to the outer peripheral surface of the container. Japanese Patent Application Laid-Open No. 5-285981 proposes a molding apparatus that accurately molds the in-mold.
[0007]
As shown in FIG. 4, in the invention described in the above publication, in a general injection molding apparatus, a female mold (lower mold) 36 and a male mold (upper mold) 38 are mold clamping base plates 32, 32. And a cavity 37 for molding the container 1 is formed by fitting the female mold and the male mold.
The female mold 36 is provided with an injection port 34 to which the tip of the nozzle 33 of the injection molding machine is engaged in the bottom wall portion, and a suction hole for adsorbing and fixing the sticking body 6 in the cavity 37. 35 is provided in the inner wall portion, and the suction hole 35 is connected to a suction device such as a vacuum pump through a suction tube 39 provided in the outer wall portion, and is attached to the cavity 37. The body 6 is configured to be adsorbed and held on the inner surface of the female mold.
[0008]
In the molding apparatus configured as described above, in order to mold the container 1 provided with the sticking body 6 on the outer wall surface of the container as shown in FIG. 3, as shown in FIG. After the sticking body 6 is loaded into the cavity 37 of 31 and the sticking body 6 is adsorbed and held on the inner surface of the female mold 36 by a suction device, the injection port of the female mold 36 is injected from the nozzle 33 of the injection molding machine. When the molten resin P is injected into the cavity 37 of the molding die 31 through 34, the molten resin P filled in the cavity is molded into a container having a predetermined shape, and the sticking body 6 is molded in-mold. The container 1 in which the sticking body 6 is stuck to the outer wall surface of the container is molded.
[0009]
However, in the molding die 31 as described above, since the inner peripheral surface of the female die 36 is formed as a smooth surface, the sticking body 6 mounted in the female die 36 is the inner surface of the molding die. Therefore, when the molten resin P is injected into the cavity 37 from the nozzle 33 of the injection molding machine, it is directed upward from the lower part of the cavity 37. The molten resin P injected at high speed collides with the lower end portion of the sticking body 6 such as printed thin paper or film, and the lower end portion of the sticking body 6 receives the pressure due to the fluid pressure and becomes drowned. Sometimes.
As a result, when in-mold molding is performed in a state in which the bent portion 6b is generated at the lower end portion of the sticking body 6, a phenomenon that the molten resin wraps around the surface of the sticking body 6 appears. There is room for improvement because the appearance will be damaged.
[0010]
Therefore, as described above, a method as described in Japanese Patent Application Laid-Open No. Hei 4-14420 has been proposed as in-mold molding in which a sticking portion 6b is not generated in the sticking body 6.
In the invention shown in the above publication, a notch surface or a convex portion is formed on a molding die surface where a cavity for molding a molten resin is formed, and the flow of the molten resin is caused by the notch surface or protrusions. Inducing the direction, so that the pressure of the injected molten resin is closely attached to the inner surface of the mold so that the edge of the adhesive body placed in the cavity does not generate wrinkles, In addition, the molten resin does not protrude from the surface of the sticking body.
[0011]
However, in the molding method of the invention described in the above publication, the above-described notch is used to reliably prevent the sticking of the sticking body depending on the shape of the container and the sticking position of the sticking body. When the shape or size of the surface or convex part must be determined before it is formed, and it is actually very difficult because it requires laborious work that makes the mold slightly complicated There is.
Therefore, an in-mold molding method and a molding apparatus are desired which make the molding die a little simpler and prevent the sticking body from curling or wrinkling.
[0012]
[Problems to be solved by the invention]
The invention of the present application has been devised to eliminate the above-described problems, and the sticking body is arranged at a predetermined position on the inner peripheral surface of the female die of the molding die, and the sticking body is formed by an injection molding method. In the method of forming an in-molded container, the inside of the cavity is formed from the nozzle of the injection molding machine to the end of the sticking body that is mounted in the female mold so as to be stickable to the outer wall surface of the container to be molded. An in-mold molding method and a molding apparatus container for an adhesive body that can prevent the adhesive body from curling or wrinkling can be easily and reliably prevented from colliding with molten resin injected into The purpose is to do.
[0013]
[Means for Solving the Problems]
In order to achieve the above-described object, the invention of the present application provides a container on the inner wall surface of a female mold of an injection mold in which a cavity matching the shape of the container is formed by fitting a male mold and a female mold. An injection recess is formed with a suction hole formed so that the attachment body attached to the attachment recess can be adsorbed and held while forming an attachment recess of a size to be attached to the surface of the attachment. Form a mold.
A suction tube communicating with the suction hole of the mounting recess is provided on the outer wall portion of the female mold of the injection mold, and is connected to a vacuum suction device so as to adsorb and hold the sticking body. The injection molding machine is formed by providing an injection port for engaging the nozzle of the injection molding machine at the bottom of the female mold of the injection mold, and the end of the sticking body is moved by the flow pressure of the injected molten resin. An injection molding apparatus is configured in which the sticking body is in-mold molded on the outer peripheral surface of the container so as not to be twisted.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The invention of the present application is an injection molding apparatus composed of an injection molding machine and a molding die, on the inner wall surface of the female mold 12 of the injection molding die 7 in which the cavity 13 for molding the container is formed, on the wall surface of the container. After forming the adhering recess 18 for adsorbing and holding the adhering body 6 to be adhered, attaching the adhering body 6 to the mounting recess, adsorbing and holding it, the molten resin P is removed from the injection molding machine by the cavity. 13 is injection-molded, and in-mold molding is performed so that the end 6a of the sticking body 6 is not squeezed by the flow pressure of the molten resin, so that the sticking body 6 is stuck to the outer wall surface of the container. An injection molding apparatus that can mold the container 1 is configured.
[0015]
The molding die 7 in the above-described injection molding apparatus is formed with an adhesive recess 18 that allows the adhesive body 6 to be held on the inner wall surface, and a gun 9 that can engage the nozzle 9 of the injection molding machine at the bottom. A female mold 12 having an outlet 10 and a male mold 14 that is fitted to the female mold 12 to form a cavity 13 for molding the container 1 are formed.
Further, a suction hole 11 is provided in the sticking recess 18 of the female die 12, and the sticking body 6 is connected to a suction device such as a vacuum pump through a suction pipe 15 communicating with the suction hole, whereby the sticking body 6 is molded. An injection molding device that can be sucked and held in the female die 12 is formed.
[0016]
The molding die 7 of the injection molding apparatus formed as described above is opened, the adhesive body 6 is loaded into the mounting recess 18 of the female mold 12, and the suction device is operated to paste through the suction tube 15 and the suction hole 11. After adsorbing and holding the adherend 6 in the adhering recess 18, the mold 7 is clamped so that the male mold 14 is fitted in the female mold 12, and then from the injection molding machine. The molten resin P is injected into the cavity 13 through the nozzle 9 so that the container 1 in which the sticking body 6 is stuck to the outer wall surface of the molded container can be molded.
[0017]
【Example】
Below, based on the optimal one Example, the shaping | molding method of the container which carries out the in-mold shaping | molding of the sticking body of this invention is demonstrated in detail, referring drawings.
As shown in FIG. 3, the container 1 in which the sticking body 6 is molded in-mold according to the present invention has a cylindrical body wall portion 3 that is formed in a tapered shape that extends upward and is made of a thermoplastic synthetic resin. A disc-shaped bottom wall portion 4 that closes a portion slightly above the lower end portion of the body wall portion 3 and an annular flange portion 5 that protrudes slightly outward from the upper end portion of the body wall portion 3. A sticking body 6 made of various printed thin papers, synthetic resin films, or the like is stuck to the outer wall surface of the wide-mouthed container body 2 thus formed at the same time as injection molding.
[0018]
In order to form the container 1 in which the sticking body 6 is formed in-mold, the inner wall surface of the female mold 12 of the molding die 7 is formed in an injection molding apparatus for molding the container as shown in FIG. Next, a suction concave portion 18 for mounting the sticking body 6 is formed by being depressed by an amount corresponding to the thickness of the sticking body, and the sticking body 6 is sucked and held on the wall surface of the sticking concave portion 18. A hole 11 is provided and communicated with a suction pipe 15 provided on the outer side wall surface of the female mold, and connected to a suction device such as a vacuum pump through the suction pipe, and is mounted in the sticking recess 18. A female mold 12 is formed that is capable of adsorbing and holding the adhered body 6.
An injection port 10 is formed at the bottom of the female mold 12 so that the nozzle 9 of the injection molding machine can be engaged, and is tapered so as to fit into the female mold and form a molding cavity of the container. A protruding male mold 14 is formed, and the female mold and the male mold are fixed to the mold clamping base plate 8 so that the molding die can be opened and closed. A moldable injection molding device is formed.
[0019]
And in order to shape | mold the container 1 by which the thermoplastic synthetic resin was injection-molded with the shaping | molding apparatus formed as mentioned above and the sticking body 6 was in-mold-molded, it shape | molds as follows.
First, as shown in FIG. 1, the molding die 7 of the molding apparatus is opened so that the male mold 14 and the female mold 12 are separated from each other, and the pasting body 6 is placed in the pasting recess 18 of the female mold 12. Then, the suction device is operated to adsorb the sticking body 6 in the sticking recess 18 and hold it in-mold.
[0020]
As shown in FIG. 2, the cavity 13 for molding the container is formed by fitting the male mold 14 to the female mold 12 in which the sticking body 6 is adsorbed and held in the sticking recess 18 as described above. After the molding die 7 is clamped so as to form, the molten resin P is injected by engaging the tip of the nozzle 9 of the injection molding machine with the injection port 10 provided in the bottom of the female die 12.
The injected molten resin P passes through the injection port 10 of the female mold 12 and flows into the molding space from the bottom of the cavity 13, and flows into the cylinder 13 along the trunk wall 3 of the container 1 in the cavity 13. As a result, the space of the cavity 13 is filled.
[0021]
At this time, in the present invention, since the sticking body 6 is adsorbed and held in the sticking recess 18, the sticking body 6 is injected into the cavity 13 to form the body wall 3 of the container 1. Even when the molten resin P flowing to the bottom reaches the lower end of the sticking body 6, it does not collide or suffers resistance, and smoothly passes along the inner surface (back side) of the sticking body 6. Therefore, the sticking body 6 is not wrinkled by the flow pressure of the molten resin P, and the end portion is not curled and the resin does not flow out to the front side.
Therefore, since the molten resin P injection-molded as described above flows into the gap 19 formed between the edge of the sticking body 6 and the peripheral edge of the sticking recess 18, the sticking body 6 is The back surface is bonded to the body wall surface of the container and in-mold molded so that the edge is surrounded by the molten resin.
[0022]
After the sticking body 6 is molded in-mold on the body wall surface of the container as described above, the suction operation of the suction device is stopped to release the sticking and holding state of the sticking body 6, and then the molding die When the mold clamping is opened, the male mold 14 and the female mold 12 are separated, and the container 1 in which the sticking body is in-molded can be taken out.
The container 1 injection-molded in this way has the sticking body 6 firmly joined to the body wall surface.
[0023]
Since the present invention is formed so that the entire adhering body 6 that adsorbs and holds the adhering recess 18 formed on the inner wall surface of the female mold 12 is accommodated therein, the shape of the adhering recess 18 Are formed in a rectangular shape, a polygonal shape, a circular shape, an elliptical shape, or other shapes according to the shape of the sticking body 6, and are formed in a slightly larger similar shape than the sticking body 6.
And it is formed so that a little clearance 19 may be formed between the edge part of the sticking body 6 and the peripheral part of the sticking recessed part 18, Furthermore, the sticking body 6 with which the depth of the sticking recessed part 18 is mounted | worn. Since the back surface and the side end surface are in contact with the molten resin, the sticking body 6 is in-mold molded on the container surface more firmly. Yes.
[0024]
【The invention's effect】
As described above, the present invention forms an adhesive recess corresponding to the thickness of the adhesive body on the inner wall of the female mold of the molding die, and attaches the adhesive body to the adhesive recess to attach the container. Because it is molded in-mold, the injected molten resin does not collide with the end of the sticking body, so it is possible to securely hold the sticking body made of printed thin paper, synthetic resin film, etc. it can.
Further, the present invention has a simple structure because the molding die is simply provided with a slight recess for loading the sticking body in the suction and holding portion in the molding die provided with the conventional suction and holding means. Since the molten resin flows into the dent gap between the sticking body and the sticking recess, the outer edge of the sticking body is also stuck to the container. Can be more firmly attached to the container.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a state immediately before a mold is clamped by attaching, holding, and holding a sticking body to a molding die in an injection molding apparatus used in the present invention.
2 is a cross-sectional view showing a state where a molding die of the molding apparatus shown in FIG. 1 is closed and injection-molded. FIG.
FIG. 3 is a perspective view showing a container in which a sticking body is molded in-mold.
FIG. 4 is a cross-sectional view showing a state in which a molding die is closed and injection molded in a conventional molding apparatus.
[Explanation of symbols]
1. 5. Container in which the sticking body is molded in-mold. 6. Adhesive body Molding die8. Clamp base 9 Injection nozzle 10. Injection port 11. Suction hole 12. Female mold 13. Mold cavity 14. Male mold 17. Mold inner wall 18. Sticking recess 19. Gap P. Molten resin

Claims (5)

After attaching the sticking body to the sticking recess formed to hold the label-like thin sticking body written about the product name, contents, etc. on the inner peripheral wall part of the female mold of the molding die of the injection molding device, After the molding die is closed with the sticking body adsorbed and held in the sticking recess, it is melted from the bottom of the molding die so that the end of the sticking body is not crushed by the injection flow pressure of the molten resin. By injecting resin and performing in-mold molding, a container is formed, and at the same time, a container is formed by bonding the above-mentioned adhesive body to the outer peripheral wall surface of the container. A method for forming a molded container. In an injection molding machine that in-mold molds an adhesive body on a thermoplastic resin molded article and attaches the adhesive body to the surface of the molded article , the product name and content on the inner peripheral wall surface of the molding die A sticking concave portion for adsorbing and holding a thin label-like sticking body, which is described with respect to articles and the like, is formed in an amount corresponding to the thickness of the sticking body, and a suction hole is provided in the sticking concave portion and communicated with the suction hole. A suction tube is provided on the outer wall portion of the molding die, clamped and formed into a molding die that can be opened, and a suction device is connected to the suction tube, and is attached to the sticking recess. A molding die is formed so as to adsorb and hold the sticking body, and an injection port for engaging an injection nozzle of an injection molding machine is formed at the bottom of the molding die to form a cavity of the molding die. injected molten resin collides with the end portion of the bonded adherend within, or turning up the end edge of a resin pressure Molding apparatus vessel for in-mold molding the adhered body attaching member, characterized in that the moving obtained by forming the bonded recess shape is not displaced from the predetermined position. The molding die is formed of a male mold and a female mold, and an adhesive recess that can adsorb and hold the thin adhesive body is formed on the inner peripheral wall of the female mold, and the adhesive recess is 3. A molding apparatus for a container for in-mold molding of an adhesive body according to claim 2, wherein an edge portion of the attached adhesive body is formed in a shape that does not squeeze due to an injection pressure of a molten resin. . The adhesive recess for adsorbing and holding the adhesive body is formed at a depth equal to the thickness of the adhesive body so that the end of the adhesive body does not protrude , 4. An apparatus for forming a container for in-mold molding an adhesive body according to claim 2, wherein the edge portion is prevented from being bent. The adhering recess for adsorbing and holding the adhering body is slightly larger than the peripheral shape of the adhering body to be adhered, and a molten resin between the peripheral edge of the adhering body and the inner peripheral edge of the adhering concave portion. 4. A molding apparatus for a container for in-mold molding of an adhesive body according to claim 2, wherein a slight gap is formed so that the end edge of the adhesive body by pressure is not broken.

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