JP7221757B2 - Mold device for forming in-mold label container and method for forming in-mold label container - Google Patents

Description

The present invention relates to a mold device for molding an in-mold label container and a method for molding an in-mold label container. The present invention relates to a mold apparatus and method for injection molding an in-mold labeled container having an in-mold label heat-sealed thereon.

In-mold molding, in which a film-like in-mold label is heat-sealed onto the outer peripheral surface of the peripheral wall of the container when the container is injection-molded, is more efficient in the manufacturing process than attaching the label to the container later. commonly practiced. An in-mold container is called an in-mold label container and generally includes a bottom wall, a cylindrical peripheral wall, and a flange protruding outward from the upper end of the peripheral wall. The upper end opening surrounded by the flange of the container is open, and the upper end opening is separately provided with a lid. The in-mold label can provide the container with an oxygen barrier property that reduces oxygen permeation between the inside and outside of the container, and this performance is particularly important when the content of the container is food or the like.

FIG. 20 is a front view showing an example of an in-mold label container (hereinafter also simply referred to as “container”) 201. As shown in FIG. The vertical direction of the container 201 is based on the plane of FIG. 20 unless otherwise specified. As an example, the container 201 includes a disk-shaped bottom wall 202, a peripheral wall 203 cylindrically extending upward from the peripheral edge of the bottom wall 202, and a flange projecting radially outward from the upper end of the peripheral wall 203 with respect to the axis A' of the container 201. 204. The container 201 has a top opening surrounded by a flange 204 and opening upward. A lid is separately provided on the upper end opening. The peripheral wall 203 gradually increases in diameter upwardly. The container 201 has an outer surface 202a and an inner surface 202b of the bottom wall 202, an outer surface 203a and an inner surface 203b of the peripheral wall 203, a rear surface 204a and a surface 204b of the flange 204, and a radially outer end surface 204c of the flange 204. have An in-mold label (hereinafter also simply referred to as “label”) 110 is provided so as to cover the entire outer peripheral surface 203a of the peripheral wall 203 and part of the back surface 204a of the flange 204, for example.

FIG. 21 is a cross-sectional view schematically showing a mold open state of a fixed mold 120 and a movable mold 130 in a conventional mold for molding the in-mold label container 201. As shown in FIG. In the following description based on FIGS. 21 to 25, the horizontal direction is based on the paper surfaces of FIGS. 21 to 25 unless otherwise specified. The fixed mold 120 and the movable mold 130 are horizontally arranged concentrically with the axis H. As shown in FIG. A movable mold 130 advances and retreats with respect to a fixed mold 120 fixedly arranged on the left side, and mold closing and mold opening are performed. Fixed mold 120 has a fixed mold cavity surface 120a and movable mold 130 has a movable mold cavity surface 130a. The fixed mold cavity surface 120a includes a bottom wall outer cavity surface 121 corresponding to the outer surface of the bottom wall of the container, a peripheral wall outer cavity surface 122 corresponding to the outer peripheral surface of the peripheral wall, and a flange back cavity surface 123 corresponding to the back surface of the flange. including. The movable mold cavity surface 130a includes a bottom wall inner cavity surface 131 corresponding to the inner surface of the bottom wall of the container, a peripheral wall inner cavity surface 132 corresponding to the inner peripheral surface of the peripheral wall, and a flange surface cavity surface corresponding to the flange surface. 133. In in-mold molding, the label 110 in a cylindrically wound state is inserted into a fixed mold 120 and set on the outer cavity surface 122 of the peripheral wall as shown in FIG. Next, the movable mold 130 is brought closer to the fixed mold 120 to close the mold. A cavity is defined between the fixed mold cavity surface 120 a of the fixed mold 120 and the movable mold cavity surface 130 a of the movable mold 130 . By filling the cavity with molten resin, the label is integrated on the outer peripheral surface of the peripheral wall of the container, and the in-mold label container is injection molded. During this injection molding, the label 110 is set on the outer cavity surface 122 of the fixed mold 120 . At this time, the right end portion 110a of the label 110 is arranged closer to the movable mold 130 than the outer cavity surface 122 of the peripheral wall. The right end 110a of the label 110 is folded onto the flange back cavity surface 123 by filling resin into the cavity so as to cover the back surface of the flange. However, in this case, there are the following problems.

FIG. 22 is a partially enlarged sectional view schematically showing the cavity of the flange when the fixed mold 120 and the movable mold 130 are closed. Also, FIG. 22 shows the state before the cavity is filled with resin. In FIG. 22, Ca is a peripheral wall cavity portion corresponding to the peripheral wall of the container in the cavity, and Cb is a flange cavity portion corresponding to the flange of the container. The flange cavity portion Cb extends radially outward from the right end portion of the peripheral wall cavity portion Ca. The cavity also includes a bottom wall cavity portion (not shown) corresponding to the bottom wall of the container.

23 is a partially enlarged cross-sectional view showing a state in which the cavity including the peripheral wall cavity portion Ca and the flange cavity portion Cb is filled with resin from the state of FIG. 22. FIG. In the state of FIG. 22, the right end portion 110a of the label 110 is separated from the outer peripheral wall cavity surface 122 of the fixed mold 120 and protrudes from the flange back cavity surface 123 by the length L1 to the right flange cavity portion Cb. This protruding length L1 is set to the length up to the flange surface cavity surface 133 of the movable mold 130 in the mold closed state. The right end portion 110a of the label 110 is pushed toward the flange cavity portion Cb by filling with molten resin. Therefore, as shown in FIG. 23, it is bent radially outward on the flange side and placed on the flange back cavity surface 123 . This brings the right edge 110a of the label 110 to the underside of the molded container flange.

However, when the radial length L2 (see FIG. 22) of the flange back cavity surface 123 is longer than the protrusion length L1 of the right end portion 110a of the label 110, the label 110 is positioned behind the flange as shown in FIG. The radially outer edge 124 of the cavity face 123 is not reached. This leaves a portion of the back surface of the flange of the container that is not covered by the label 110 radially outward. In this case, oxygen is allowed to permeate from the radially outer portion of the back surface of the flange that is away from the label 110, thereby degrading the oxygen barrier properties of the container. In order to prevent this, it is conceivable to make the projecting length of the right end portion 110a of the label 110 longer than the radial length L2 of the flange back cavity surface 123. FIG.

FIG. 24 is a partially enlarged cross section showing the case where the projection length of the right end portion 110a of the label 110 is set to a projection length L1' longer than the projection length L1 of FIG. Here, the projection length of the right end portion 110 a of the label 110 is the projection length of the right end portion 110 a of the label 110 from the flange back cavity surface 123 . FIG. 24 is a partially enlarged cross-sectional view showing the state of the fixed mold 120 and the movable mold 130 just before the molds are closed, and shows the time when the right end of the label 110 contacts the movable mold 130 . 25 is a partially enlarged cross-sectional view showing a state in which the mold is closed from the state of FIG. 24. FIG. As shown in FIG. 24, in the case of the label 110 with the protrusion length set to L1′ longer than L1, the right end of the label 110 is the flange of the movable mold 130 immediately before the fixed mold 120 and the movable mold 130 close. The mold is closed while the right end of the label 110 is pushed leftward by the movable mold 130 in contact with the front cavity surface 133 . Therefore, as shown in FIG. 25, the label 110 may be buckled, or the label 110 may be wrinkled by being randomly bent radially inward and outward. Therefore, in the conventional fixed mold 120 and the movable mold 130, the right end portion 110a of the label 110 is spread over the flange back cavity surface 123 of the fixed mold 120, and the back surface of the flange of the container to be molded is in-mold. There was a limitation in terms of covering more with the label.

Japanese Patent Application Laid-Open No. 2003-173144 (Patent Document 1) discloses a technique for making it easier for the label to cover the back surface of the flange of the container during injection molding of the container by making cuts or perforations in advance in the portion corresponding to the flange of the in-mold label. is proposed.

JP-A-2003-173144

However, in the label disclosed in Patent Document 1, the portion corresponding to the flange tends to bend not only radially outwardly but also radially inwardly during injection molding, making it difficult to successfully arrange the entire flange corresponding portion of the label on the back surface of the flange. In addition, there is a problem that the cut portion of the label located on the back surface of the flange of the container widens to form a gap, impairing the oxygen barrier property.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an in-mold label container molding mold device capable of molding an in-mold label container having improved oxygen barrier properties than the conventional one. An object of the present invention is to provide an in-mold label container molding method.

One mold for forming an in-mold label container according to the present invention, which can solve such problems, has a bottom wall, a peripheral wall, and an end of the peripheral wall on the opposite side of the bottom wall in the axial direction that protrudes to the outer peripheral side. A mold device for molding an in-mold label container for injection molding an in-mold label container comprising a flange and an in-mold label integrated with the outer peripheral surface of the peripheral wall, the mold device comprising: a mold comprising a first mold having one cavity surface and on which the in-mold label is set; and a second mold having a second cavity surface; a label pressing unit that presses the set in-mold label against the first cavity surface side of the first mold.

A method for forming an in-mold label container according to the present invention that can solve the above-mentioned problems includes a bottom wall, a peripheral wall, a flange protruding outward from an end of the peripheral wall opposite to the bottom wall, and an in-mold label integrated with the outer peripheral surface of the peripheral wall, and an in-mold label container molding method using a mold, wherein the mold is a first cavity surface. and a second mold having a second cavity surface, wherein the method includes removing the in-mold label set in the first mold from the first mold during closing of the mold. and a step of transferring the pressing of the in-mold label to the first mold side to the second mold.

Advantageous Effects of Invention According to the present invention, it is possible to provide an in-mold label container molding die device and an in-mold label container molding method that can improve the oxygen barrier property of a container.

FIG. 1 is a sectional view of a mold device for molding an in-mold label container according to one embodiment of the present invention. FIG. 2 is a front view of the movable stripper viewed from the stationary die side. FIG. 3 is a front view seen from the same direction as FIG. 2 showing two label pressing members protruding forward from the accommodating portion. FIG. 4 is an enlarged view showing a radial cross section of the label pressing member. FIG. 5 is an enlarged cross-sectional view of a portion of the front wall of the stripper corresponding to box B in FIG. FIG. 6 is a partial cross-sectional side view schematically showing an injection molding machine to which the mold device for molding an in-mold label container according to the present invention is detachably attached. FIG. 7 is an overall view schematically showing an in-mold molding system. FIG. 8 is a cross-sectional explanatory view of the movable die of the die device and the label pressing machine in the initial state. 9 is a cross-sectional explanatory view showing a state in which the stripper is moved forward with respect to the core from the initial state of FIG. 8. FIG. 10 is a cross-sectional explanatory view showing a state in which the extruder is operated from the state of FIG. 9 to move the radial direction guide from the rear to the front in the space. FIG. 11 is a cross-sectional explanatory view showing the point in time when the stripper and the core are integrally moved forward from the state of FIG. 10 and the end of the label contacts the pressing member. FIG. 12 is a cross-sectional illustration showing a state in which the stripper and core are advanced slightly from the state of FIG. 11 and the label end portion of the label pressing surface of the pressing member begins to bend radially outward. FIG. 13 is a cross-sectional view showing a state in which the tripper and core are further advanced slightly from the state of FIG. 12, and the end of the label is bent radially outward at the label pressing surface of the pressing member. FIG. 14 is a cross-sectional explanatory view showing a state in which the stripper and the core are further advanced from the state of FIG. 13 and the mold is closed. 15 is a partially enlarged cross-sectional view of the vicinity of the edge of the label in FIG. 12. FIG. FIG. 16 is a partially enlarged cross-sectional view showing a state in which the movable core and stripper are slightly advanced from the time of FIG. 17 is a partially enlarged cross-sectional view showing a state in which the core and stripper have advanced slightly from the point in FIG. 16. FIG. FIG. 18 is a partially enlarged cross-sectional view showing a state in which the movable mold moves forward from the time of FIG. 17 and the mold is closed. 19 is a partially enlarged cross-sectional view showing a state in which the cavity is filled with molten resin from the state of FIG. 18. FIG. FIG. 20 is a front view showing an example of an in-mold label container. FIG. 21 is a cross-sectional view schematically showing a mold open state of a fixed mold and a movable mold in a conventional mold for molding an in-mold label container. FIG. 22 is a partially enlarged cross-sectional view of the vicinity of the flange-corresponding portion of the cavity, schematically showing the state before the cavity is filled with resin. 23 is a partially enlarged cross-sectional view showing a state in which the cavity including the peripheral wall cavity portion and the flange cavity portion is filled with resin from the state of FIG. 22. FIG. FIG. 24 shows the state of a conventional fixed mold and a movable mold immediately before closing when the length of projection from the cavity surface behind the flange on the right end of the label is set to be longer than the projection length of FIG. It is a partially enlarged cross-sectional view. 25 is a partially enlarged cross-sectional view showing a state in which the mold is closed from the state of FIG. 24. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to such embodiments, and can be appropriately modified within the scope of claims and equivalents.

FIG. 1 is a sectional view of a mold device for molding an in-mold label container (hereinafter also simply referred to as "mold device") 1 according to one embodiment of the present invention. The mold device 1 includes a mold and a label pressing section 30 . The mold includes a fixed mold 10 as a first mold and a movable mold 20 as a second mold. In FIG. 1, the stationary mold 10 and the movable mold 20 are in a mold open state. In FIG. 1, the movable mold 20 is in its initial state. FIG. 1 also shows a state in which an in-mold label (hereinafter also simply referred to as a “label”) 2 is set on a peripheral wall outer cavity surface 12 of the fixed mold 10, which will be described later. The fixed mold 10 and the movable mold 20 are arranged concentrically with respect to the axis A, and the movable mold 20 advances and retreats with respect to the fixed mold 10 fixedly arranged on the left side of the paper surface of FIG. opening is performed.

The fixed mold 10 has a fixed mold cavity surface 10a as a first cavity surface. The movable mold 20 has a movable mold cavity surface 20a as a second cavity surface. A cavity C (see FIG. 6) for molding an in-mold label container is formed between the fixed mold cavity surface 10a and the movable mold cavity surface 20a when the mold is closed.
A peripheral wall 203 of the container 201 is cylindrical. The tube shape includes not only a cylindrical tube but also a rectangular tube. In other words, the tubular shape includes not only a circular cross-section, but also a rectangular cross-section, an elliptical cross-section, an oval cross-section, a polygonal cross-section, an annular cross-section having a straight line and a curved line, and the like. The shape of the peripheral wall 203 may be a shape that allows the label 2 to be integrally molded without causing wrinkles or the like. In this example, the inclination angle of the peripheral wall 203 is set to an angle that makes it difficult for the label 2 to wrinkle during injection molding, taking into consideration the strength of the label 2 and the like. The fixed mold cavity surface 10a includes: a bottom wall outer cavity surface 11 corresponding to the outer surface 202a of the bottom wall 202 of the container 201; a peripheral wall outer cavity surface 12 corresponding to the outer peripheral surface 203a of the peripheral wall 203; A corresponding flange back cavity surface 13 and a flange end back cavity surface 14 corresponding to the flange back cavity surface 13 half at the radially outer end surface 204 c of the flange 204 . Reference number 15 is the movable mold facing surface of the fixed mold 10 . The outer peripheral wall cavity surface 12 slightly expands in diameter with respect to the axis A toward the axial flange back cavity surface 13 side. Reference numeral 16 in FIG. 1 denotes a passage provided in the fixed mold 10 for filling the cavity C with molten resin from an injection device 40, which will be described later.

The movable die 20 includes a core 20A and a stripper 20B. Core 20A and stripper 20B include the following as movable mold cavity surfaces 20a.
The core 20</b>A has a bottom wall inner cavity surface 21 corresponding to the inner surface 202 b of the bottom wall 202 of the container 201 and a peripheral wall inner cavity surface 22 corresponding to the inner peripheral surface 203 b of the peripheral wall 203 . The movable mold cavity surface 20a includes a flange front cavity surface 23 corresponding to the surface 204a of the flange 204, and a flange end front cavity surface 24 corresponding to the half of the flange front cavity surface 23 side of the radially outer end surface 204c of the flange 204. have In the following description of the movable mold 20, the side of the movable mold 20 that approaches the fixed mold 10 in the axial direction is defined as the front side, and the side that the movable mold 20 moves away from the fixed mold 10 in the axial direction is defined as the rear side. The core 20A includes a center core 20Aa having a bottom wall inner cavity surface 21 and a peripheral wall inner cavity surface 22, and a core base 20Ab whose diameter increases at the rear end of the center core 20Aa. The stripper 20B is arranged around the center core 20Aa, and can be moved from the initial position shown in FIG. As a result, the stripper 20B can push forward the container 201, which is a molded product held on the center core 20Aa when the mold is opened after molding, from the center core 20Aa. In the present invention, the ejector device 70 of the injection molding machine 100 can be used as part of the movement mechanism 30M of the label pressing section 30, which will be described later. Further, a mechanism for moving the stripper 20B, which is separate from the ejector device 70, can be incorporated in the movable mold 20 of the mold device 1 or the movable platen 62 of the mold clamping device 60, which will be described later.

The stripper 20B has a disk-shaped front wall 20Ba and a peripheral side wall 20Bb extending rearward from the radially outer end of the front wall 20Ba. A space S exists behind the front wall 20Ba and radially inside the peripheral side wall 20Bb. The space S accommodates a later-described radial guide 34 of the label pressing portion 30 and the like. The radial guide 34 is located behind the space S in the initial state of the movable mold 20 in FIG.

The label pressing unit 30 of the mold device 1 bends the end 2a of the label 2 on the side of the movable mold 20, which is set on the fixed mold 10 in the mold open state, radially outward when the mold is closed, and presses the flange surface of the movable mold 20. It is a mechanism for delivering to the cavity surface 23 . Various forms of realizing such a mechanism are conceivable, and the label pressing section 30 of the present embodiment is merely one example. The label pressing portion 30 includes two label pressing members 31 (hereinafter also simply referred to as “pressing members”), and the pressing members 31 are positioned between an initial position and a label engaging position (to be described later) where the label 2 is engaged. and a moving mechanism 30M for moving to. Each pressing member 31 is accommodated in an accommodating portion 26 recessed rearward from the front surface 25 of the front wall 20Ba of the stripper 20B in the initial state of the movable die 20. As shown in FIG. In this embodiment, two examples of the pressing member 31 are given, but the number of pressing members may be one or three or more. In the present embodiment, the housing portion 26 is provided in the stripper 20B, but the present invention is not limited to this. For example, the stripper 20B may be configured by a portion corresponding to a cavity surface corresponding to a flange cavity C4, which will be described later, and the accommodating portion 26 may not be configured as the stripper 20B.

The moving mechanism 30M includes a connecting rod 32 as a rod member whose front end is fixedly connected to each pressing member 31, a slide member 33 whose rear end is pivotably connected, and a slide member 33. It includes a radial guide 34 that guides the slide along the radial direction and a drive 35 that moves the radial guide 34 back and forth. Radial guide 34 is positioned behind space S in the initial state of FIG. The drive unit 35 can push the radial guide 34 located behind the space S forward into the space S by means of an expansion member 36 such as a cylinder rod (illustrated only in FIG. 10). As the driving portion 35, the radial direction guide 34 may be pushed forward from the rear of the space S. The rearward movement of the radial guide 34 is automatically carried out by the movable die 20 advancing relative to the stationary rod member 32 after the pressing member 31 contacts the stationary die 10 and the forward movement is restricted. may be broken. In this embodiment, an example in which substantially the same moving mechanism 30M is applied to each of the two pressing members 31 is given. Alternatively, a plurality of pressing members may be moved. The moving mechanism 30M can utilize not only a mechanism incorporated in the fixed mold 10 of the mold apparatus 1, but also a mold clamping device 60 and an ejector device 70 generally provided in the injection molding machine 100, which will be described later.

FIG. 2 is a front view of the stripper 20B of the movable mold 20 viewed from the fixed mold 10 side, and FIG. 2 shows the front surface 25 of the front wall 20Ba of the stripper 20B. Note that the cross section of the movable die 20 shown in FIG. 1 is taken along line DD in FIG. As can be seen from FIG. 2, each of the two pressing members 31 is a semi-annular member as an arc-shaped member. The accommodation portion 26 that accommodates the two pressing members 31 is formed in an oval ring shape. One of the pressing members 31 is housed in the upper portion of the housing portion 26 in FIG. 2, and the other pressing member 31 is housed in the lower portion thereof. When each pressing member 31 is accommodated in the accommodation portion 26 , a gap g exists between the circumferential ends 31 a of one pressing member 31 and the circumferential ends 31 a of the other pressing member 31 . An annular elastic member such as a spring or rubber may be arranged on the outer periphery surrounding the two pressing members 31 . The elastic member may be configured to always urge the pressing member 31 in the direction in which the circumferential ends 31a are in contact with each other. FIG. 3 is a front view showing two pressing members 31 protruding forward from the housing portion 26. As shown in FIG. When the two pressing members 31 are moved forward from the accommodating portion 26, their circumferential ends 31a are in contact with each other to form an annular shape. Therefore, there is no gap g between both pressing members 31 . When the two ring-shaped pressing members 31 are re-accommodated in the accommodation portion 26, the gap g is created again.

In FIG. 2, the connection of the connecting rod 32 to each pressing member 21, the slide member 33 and the radial guide 34 are indicated by dashed lines. A front end of each connecting rod 32 is connected to each pressing member 21 at a circumferential intermediate portion of each pressing member 21 . Each radial guide 34 including the slide member 33 is also arranged in the circumferentially intermediate portion of each pressing member 21 .

FIG. 4 is an enlarged view showing a cross section along the radial direction of the pressing member 31. As shown in FIG. The pressing member 31 has a front surface 31b, a rear surface 31c, an inner peripheral surface 31d, and an outer peripheral surface. The front surface 31b and the rear surface 31c are parallel to the front surface 25 of the stripper 20B, in other words, perpendicular to the axis A. The front surface 31b and the rear surface 31c are maintained perpendicular to the axis A during movement of the pressing member 31, which will be described later. A front surface 31b of the pressing member 31 is formed with a label pressing surface 31L and a fixed contact surface 31M. The label pressing surface 31L has a first label pressing surface 31A and a second label pressing surface 31B. In addition, a concave portion 31e recessed rearward is provided on the front surface 31b of the pressing member 31 over the entire length of the pressing member 31 in the circumferential direction. The recess 31e is provided between the label pressing surface 31L and the fixed contact surface 31M. The recess 31e may not be provided. The concave portion 31e has a first label pressing surface 31A, which is an inclined surface whose outer diameter expands rearward, on the inner side in the radial direction. A second label pressing surface 31B is provided on the front surface 31b of the pressing member 31 radially inside the first label pressing surface 31A. By making the first label pressing surface 31A an inclined surface, the relative angle with the label 2 is reduced. The first label pressing surface 31A is an inclined surface so that the relative angle with respect to the label 2 set on the fixed mold 10 is small. The first label pressing surface 31A is an inclined surface whose outer diameter expands rearward. Therefore, when the first label pressing surface 31A presses the label 2, it becomes easier to guide the label 2 radially outward of the mold device 1 along the inclined surface. Therefore, the label 2 is prevented from wrinkling due to the pressing of the label 2 by the label pressing portion 31A. An inner peripheral surface 31d of the pressing member 31 is an inclined surface whose inner diameter expands rearward. The inclination angle of the inner peripheral surface 31d with respect to the front surface 31b is slightly larger than the inclination angle of the first label pressing surface 31A of the recess 31e. The connecting rod 32 indicated by the dashed line in FIG. 4 is, as an example, an elongated cylindrical member that is inclined rearwardly and radially outwardly with respect to the radially outer portion of the rear surface 31c at the circumferentially intermediate portion of the pressing member 31. fixedly connected. The connecting rod 32 is movable only in the direction (see arrow) along the axis of the connecting rod 32 itself by means of a rod guide 27 which will be described later.

FIG. 5 is an enlarged cross-sectional view of a portion of the front wall 20Ba of the stripper 20B corresponding to the box B in FIG. In FIG. 5, the pressing member 31 and the connecting rod 32 are not shown.
The accommodating portion 26 has an accommodating portion inner peripheral surface 26a inclined so that the diameter expands rearward, and a bottom surface 26b parallel to the front surface 25 of the stripper 20B. The inclination angle of the housing inner peripheral surface 26 a is the same as that of the inner peripheral surface 31 d of the pressing member 31 . A cylindrical rod guide 27 penetrating the front wall 20Ba of the stripper 20B is provided at a circumferential intermediate portion of the accommodation portion 26 while being inclined backward and radially outward from the accommodation portion 26 . The front end of the rod guide 27 opens radially outward of the bottom surface 26b of the housing portion 26, and the rear end of the rod guide 27 communicates with the space S. As shown in FIG. The connecting rod 32 connected to the pressing member 31 is passed through the rod guide 27, and restricts the moving direction of the connecting rod 32 to the direction along the axis of the connecting rod 32 itself.

A sliding member 33 to which the rear end of the connecting rod 32 is pivotally connected is constrained so as to be slidable only in the radial direction between the front and rear track plates 34a, 34b of the radial guide 34. As shown in FIG. Although not shown, the front raceway plate 34a has a radially elongated through groove through which the connecting rod 32 is passed. The slide member 33 follows the change in radial position of the rear end of the connecting rod 32 and slides between the track plates 34a, 34a. In the state where the pressing member 31 is housed in the housing portion 26 , the rear end of the connecting rod 32 and the slide member 33 are positioned radially outward in the radial guide 34 . On the other hand, in the state where the pressing member 31 protrudes most forward from the accommodating portion 26 , the rear end of the connecting rod 32 and the slide member 33 are located most radially inward in the radial direction guide 34 .

FIG. 6 is a partially cross-sectional side view schematically showing an injection molding machine 100 to which the mold device 1 for molding an in-mold label container according to the present invention is attached. The mold device 1 is detachably attached to the injection molding machine 100 . The injection molding machine 100 constitutes an in-mold label container injection molding system 103 together with the mold apparatus 1 according to the present invention. The injection molding machine 100 includes an injection device 40 that injects a molten molding material into a cavity C between a fixed mold 10 and a movable mold 20, a moving device 50 that moves the injection device 40 back and forth with respect to the fixed mold 10, A mold clamping device 60 for opening and closing the movable mold 20 by moving the movable mold 20 in the front-rear direction with respect to the fixed mold 10, and an ejector device 70 for taking out the molded product container 201 from the movable mold 20 in the open state. . The injection device 40 , the moving device 50 , the mold clamping device 60 and the ejector device 70 are arranged on the upper frame 102 of the base 101 of the injection molding machine 100 . In the description of the injection device 40 and the moving device 50, the direction of movement of the screw during charging of the molding material is defined as the front, and the direction of movement of the screw during metering of the molding material is defined as the rear. In the description of the mold clamping device 60 and the ejector device 70, the direction of movement of the movable mold when closing the mold is defined as the front, and the direction of movement of the movable mold when the mold is opened is defined as the rear.

The injection device 40 includes a cylinder 41 extending toward the stationary mold 10 , a screw 42 arranged concentrically with the cylinder 41 inside the cylinder 41 and provided with spiral flights around it, and a It has a band-like heater 43 that surrounds the circumference thereof, and a motor box 44 that is arranged on the rear side of the cylinder 41 and the screw 42 . Although not shown, a metering motor for rotating the screw 42 around the central axis, an injection motor for displacing the screw 42 in the front-rear direction, and the like are arranged in the motor box 44 . The metering motor rotates the screw 42 to melt the molding material in the cylinder 41 and feed the cylinder 41 forward. The rear part of the cylinder 41 is provided with a supply port 41a to which a hopper for charging molding material into the cylinder 41 can be attached. A nozzle 45 having a reduced diameter is provided at the tip of the cylinder 41 so as to come into contact with a stationary platen 61, which will be described later. The molding material introduced into the cylinder 41 from the supply port 41 a is heated and melted by the heater 43 and conveyed forward by the screw 42 . When a predetermined amount of molten resin is accumulated at the tip of the cylinder 41, it is injected into the cavity C from the nozzle 45 through the passage 20b (see FIG. 1) provided in the fixed mold 10. As shown in FIG.

The moving device 50 is provided, for example, under the motor box 44 of the injection device 40, and can move the injection device 40 back and forth with respect to a fixed platen 61, which will be described later. The moving device 50 includes, for example, a hydraulic cylinder 53 fixed to the injection device 40 and a piston rod 54 having one end fixed to the stationary platen 61 and the other end housed in the hydraulic cylinder 53 . . The injection device 40 is movable via a slide base 52 with respect to a linear guide 51 fixed on the upper frame 102 . The moving device 50 allows the injection device 40 to approach or separate from the mold 200 side, thereby enabling, for example, the nozzle 45 of the injection device 40 to be pressed against the stationary platen 61 with a predetermined pressure.

The mold clamping device 60 includes a fixed platen 61 to which the fixed mold 10 is detachably fixed, a movable platen 62 to which the movable mold 20 is detachably fixed, and a platen moving mechanism 63 which moves the movable platen 62 back and forth. Prepare. The platen moving mechanism 63 includes a rear platen 64 arranged on the upper frame 102, a mold clamping motor 65 provided on the rear surface of the rear platen 64, and a motion conversion mechanism that converts the rotary motion of the mold clamping motor 65 into a linear motion in the front-rear direction. 66 and a toggle mechanism 67 that increases the force transmitted to the motion conversion mechanism 66 and transmits it to the movable platen 62 . The toggle mechanism 67 is formed by connecting a plurality of links 67a to 67c that connect the movable platen 62 to the output portions of the rear platen 64 and the motion conversion mechanism 66 with pins so as to be swingable. Reference number 68 in FIG. 6 denotes a plurality of tie bars that connect the stationary platen 61 and the rear platen 64 . The movable platen 62 of the mold clamping device 60 can incorporate a part of the moving mechanism 30M of the mold device 1, such as the extruder 35 for pushing the radial guide 34 forward. Also, a part of a moving mechanism different from the above-described moving mechanism 30M, which can move the pressing member 31 as desired, can be incorporated in the movable platen 62 .

The ejector device 70 includes an ejector motor 73 , a motion direction conversion mechanism 72 that converts the rotary motion of the ejector motor 73 into linear motion, and a movable member 71 that moves back and forth by the motion direction conversion mechanism 72 . The container 201, which is a molded product held by the movable mold 20 in the open state, is pushed forward through the movable member 71 by the stripper 30B described herein as a part of the movable mold 20, and The container 201 is sucked by the sucker 91 of the container take-out unit 90 (see FIG. 7). The ejector device 70 is for ejecting the container 201, which is a molded product held on the center core 20Aa of the movable mold 20 in the open state. In this embodiment, the ejector device 70 is used to move the pressing member 31 of the mold device 1 through movement of the stripper 20B, in addition to its original purpose of pushing out the container 201 . Therefore, the ejector device 70 constitutes a part of the moving mechanism 30M of the label pressing section 30. As shown in FIG. A mechanism for moving the stripper 20B independently of the ejector device 70 can be incorporated into the movable mold 20 of the mold device 1, the movable platen 62 of the mold clamping device 60 of the injection molding machine 100, and the like.

FIG. 7 is an overall view schematically showing an in-mold molding system including a unit that supplies the label 2 to the fixed mold 10 and a unit that takes out the container 201, which is the molded product, from the movable mold 20 and carries it out to the next process. be. The in-mold molding system includes the injection molding machine 100 described above. Note that only a portion of the injection molding machine 100 is shown in FIG. A part of the in-mold molding system is disclosed in Japanese Unexamined Patent Application Publication No. 2010-99914. The fixed mold 10 is fixed to a fixed platen 61 of a mold clamping device 60 , and the movable mold 20 is fixed to a movable platen 62 . By moving the movable platen 62 back and forth by the platen moving mechanism 63 described above, the movable mold 20 can move between the mold opening position and the mold closing position in the front and rear direction. The in-mold molding system includes a label supply unit 80 for supplying the label 2 in a cylindrically wound state to the cavity of the fixed mold 10, and an in-mold product after being molded and cooled by the mold 200. and a container take-out unit 90 for taking out the mold label container 201 from the movable mold 20 and conveying it to the next process. The mold device 1 according to the present invention constitutes an in-mold label container molding system 104 together with the label supply unit 80 .

The label supply unit 80 includes a pseudo core 81 having substantially the same outer shape as the core 20A of the movable mold 20, an arm 82 for rotating the pseudo core 81 around the axis F, and the pseudo core 81 on the axis of the mold device 1. and a moving mechanism 83 for moving along A. The pseudo core 81 receives the label 2 at the label receiving position indicated by the solid line in FIG. The pseudo core 81 in this state is then turned about the axis F by the arm 82 and moved to a position concentric with the axis A. As shown in FIG. Next, the pseudo core 81 is moved to the stationary mold 10 by the moving mechanism 83 and the label 2 is placed on the outer cavity surface 12 of the peripheral wall of the stationary mold 10 . The label supply unit 80 can constitute an in-mold label container molding system together with the mold device 1 (and the injection molding machine 100).

The container pick-up unit 90 includes a suction cup 91 capable of sucking the container 201 from the bottom wall 202 , an arm 92 for rotating the suction cup 91 around the axis G, and the suction cup 91 along the axis A of the mold apparatus 1 . and a moving mechanism 93 for moving. A container 201, which is a molded product after being molded and cooled between the fixed mold 10 and the movable mold 20, moves to the mold opening position while being held by the movable mold 20. As shown in FIG. At this position, the ejector device 70 of the injection molding machine 100 described above operates. As a result, the stripper 20B moves forward (toward the fixed mold 10) with respect to the core 20A, and pushes out the container 201 on the core 20A. This container 201 is delivered to the suction cup 91 of the container take-out unit 90 indicated by the dashed line in FIG. The suction cup 91 moves forward together with the container 201 by the moving mechanism 93 . The suction cup 91 is then pivoted about the axis F by the arm 92 and moved to the release position indicated by the solid line. At this ejection position, the container 201 is ejected to the transport mechanism or the like.

Hereinafter, as an embodiment of the method for molding an in-mold label container according to the present invention, a process for molding an in-mold label container 201 using the mold device 1 for molding an in-mold label container described above will be described. Since the two sets of label pressing units 30 in this embodiment perform the same operation in synchronization, one set of label pressing units 30 will be described. FIG. 8 is an explanatory cross-sectional view of the movable mold 20 and the label pressing portion 30 of the mold device 1 in the initial state. In FIG. 8, the fixed mold 10 and the movable mold 20 are in a mold open state, and in this state, the label 2 rolled into a cylindrical shape by the label supply unit 80 in the in-mold molding system is placed on the outer cavity surface 12 of the peripheral wall of the fixed mold 10. set. In this label set state, the length of protrusion along the axial direction of the label end portion 2a protruding from the flange end back cavity surface 14 of the label 2 to the movable mold 20 side is the same as the flange back cavity surface 13 of the fixed mold 10 when the mold is closed. It is set to be longer than the axial distance between the movable mold 20 and the flange front cavity surface 23, that is, the axial distance of the flange cavity portion C4. In the initial state, the movable mold 20 is at the rearmost position, and the label pressing member 31 is housed in the housing portion 26 of the stripper 20B of the movable mold 20. As shown in FIG. Therefore, the connecting rod 32 protrudes rearward and radially outward most in the space S, and accordingly the radial guide 34 is positioned rearward of the space S, and the slide member 33 is positioned most radially outward in the radial guide 34. are doing.

FIG. 9 is a cross-sectional explanatory view showing a state in which the stripper 20B is moved forward with respect to the core 20A from the initial state of FIG. The stripper 20B can be moved by the ejector device 70 of the injection molding machine 100. FIG. As the stripper 20B advances, the pressing member 31, the connecting rod 32, the slider 33, and the radial guide 34 also advance while maintaining their arrangement with respect to the stripper 20B.

10 is a cross-sectional explanatory view showing a state in which the extruder 35 is operated from the state of FIG. 9 to move the radial direction guide 34 from the rear to the front in the space S. In FIG. 10, the radial direction guide 34 is positioned at the forefront in the space S in contact with the rear surface of the front wall 20Ba of the stripper 20B. The advancement of the radial guide 34 relative to the stripper 20B causes the connecting rod 32 to project forward of the stripper 20B along the rod guide 27 of the stripper 20B, thereby projecting the pressing member 31 forward from the receiving portion 26. As shown in FIG. The two pressing members 31 protruding forward from the housing portion 26 have an annular shape. Further, the forward movement of the connecting rod 32 along the rod guide 27 displaces the position of the rear end of the connecting rod 32 radially inward. Accordingly, the slide member 33 is displaced radially inward. In FIG. 10, the pressing member 31 and the connecting rod 27 are in a state of protruding most forward with respect to the stripper 20B, and the sliding member 33 is located in the radial direction guide 34 at the innermost position in the radial direction. The drive unit 35 can move the radial guide 34 back and forth in the space S by extending and contracting an extendable member 36 such as an electric, hydraulic, or hydraulic cylinder. Note that the drive unit 35 may move the radial direction guide 34 in the space S only from the rear to the front. The rearward movement of the radial direction guide 34 may be automatically performed by advancing the stripper 10B to the stationary die 10 after the pressing member 31 first comes into contact with the stationary die 10 to limit its forward movement. good. The drive unit 35 is shown only in FIGS. 1 and 10. FIG. Further, the radial guide 34 is guided forward and backward by an axial guide provided on the inner peripheral surface of the peripheral side wall 20Bb (not shown) of the stripper 10B. The pressing member 31 , connecting rod 32 , slide member 33 and radial guide 34 move in the mold closing direction in synchronization with the movement of the movable mold 20 .

FIG. 11 is a cross-sectional explanatory view showing the point in time when the stripper 10B and the core 10A are integrally moved forward from the state shown in FIG. The integral advancement of the stripper 10 and the core 10</b>A forming the movable mold 20 is performed by advancing the movable platen 62 of the mold clamping device 60 of the injection molding machine 100 . FIG. 12 is a cross-sectional explanatory view showing a state in which the stripper 10B and the core 10A are advanced from the state of FIG. is. At this point, the fixed mold contact surface 31M of the pressing member 31 comes into contact with the movable mold facing surface 15 of the fixed mold 10, and further advancement is restricted. FIG. 13 is a cross-sectional explanatory view showing a state in which the stripper 10B and the core 10A are further advanced from the state of FIG. is. As shown in FIG. 12, the fixed mold contact surface 31M of the pressing member 31 is in contact with the movable mold facing surface 15 of the fixed mold 10, so that the pressing member 31 and the connecting rod 32 are not displaced further forward. Therefore, when the stripper 10B moves forward with respect to the stationary connecting rod 32, the connecting rod 32 is guided along the rod guide 27 so as to protrude toward the strip space S side. As a result, the radial guide 34 leaves the front wall 10Ba of the stripper 10B and begins to move rearward in the space S10B. At the same time, the slide member 33 begins to displace radially outward within the radial guide 34 . Further, the connecting rod 32 begins to be displaced radially outward by the advancing rod guide 27, and along with this, the pressing member 31 also begins to be displaced radially outward. Due to this radially outward displacement of the pressing member 31, the label edge 2a bent by the first label pressing surface 31A is then pressed by the second label pressing surface 31B to maintain the bent state (see FIG. 16). ), is transferred from the second label pressing surface 31B to the flange surface cavity surface 23 of the stripper 20B immediately before mold closing (see FIG. 17). Transfer of the label end portion 2a to the flange surface cavity surface 23 will be described later.

FIG. 14 is a cross-sectional explanatory view showing a state in which the stripper 10B and the core 10A are further advanced from the state of FIG. 13 and the mold is closed. A cavity C for molding the container 201 is formed between the fixed mold cavity surface 10a of the fixed mold 10 and the movable mold cavity surface 20a of the movable mold 20 in this mold closed state. Hereinafter, a portion of the cavity C corresponding to the peripheral wall 203 of the container 201 will be referred to as a peripheral wall cavity portion C3, and a portion of the cavity C corresponding to the flange 204 will be referred to as a flange cavity C4. At the time of FIG. 14, the pressing member 31 is housed again in the housing portion 26 of the stripper 20B. Also, the radial guide 34 returns to the rear position in the space S, and the slide member 33 returns to the radially outermost position of the radial guide 34 . The radial guide 34 can automatically move from the front to the rear in the space S by increasing the amount of projection of the connecting rod 32 into the space S. Therefore, the driving portion 35 may be any device that can push the radial direction guide 34 from the rear to the front in the space S, and the mechanism for returning the radial direction guide 34 from the front to the rear may not be provided. Further, in the present embodiment, after advancing the stripper 10B, the stripper 10B and the core 10A are integrally moved forward, but the present invention is not limited to this. For example, the stripper 10B alone may not be moved forward, and the stripper 10B and core 10A may be moved forward integrally.

Hereinafter, the transfer of the label end portion 2a of the label 2 from the label pressing member 31 to the flange surface cavity surface 23 of the movable mold 20 will be further described. FIG. 15 is a partially enlarged cross-sectional view of the vicinity of the label end 2a of FIG. For convenience of explanation, the illustration of the connecting rod 32 is omitted in FIGS. 15, the label end portion 2a is bent radially outward by the first label pressing surface 31A of the label pressing surface 31L of the pressing member 31. As shown in FIG. 15, the fixed mold contact surface 31M of the pressing member 31 is in contact with the movable mold facing surface 15 of the fixed mold 10. As shown in FIG. FIG. 16 is a partially enlarged cross-sectional view showing a state in which the core 20A and the stripper 20B, which are the movable die 20, are advanced from the time of FIG. As the stripper 20B advances from the time of FIG. 15, the connecting rod 32 and the pressing member are displaced radially outward under the guidance of the rod guide 27 described above. Accordingly, the label end portion 2a is separated from the first label pressing surface 31A of the pressing member 31, and is pressed by the second label pressing surface 31B of the label pressing surface 31L while being bent. FIG. 17 is a partially enlarged cross-sectional view showing a state in which the core 20A and stripper 20B are advanced from the time of FIG. As the stripper 20B advances further, the pressing member 31 is displaced radially outward and begins to be accommodated in the accommodating portion 26 again. The inclined inner peripheral surface 31 d of the pressing member 31 and the inclined accommodating portion inner peripheral surface 26 a of the accommodating portion 26 facilitate accommodation of the pressing member 31 in the accommodating portion 26 . At the time of FIG. 17, the label end portion 2a is released from the second label pressing surface 31B of the pressing member 31, and while being pressed by the second label pressing surface 31B indicated by the broken line, it returns radially inward and immediately before closing the mold. is delivered to the flange front cavity surface 23 of the stripper 20B. Although the radially outward bending angle of the label end 2a delivered to the flange front cavity surface 23 is smaller than at the time of FIG. passed to.

FIG. 18 is a partially enlarged cross-sectional view showing a state in which the movable mold 20 moves forward from the time of FIG. 17 and the mold is closed. FIG. 18 shows a peripheral wall cavity portion C3 and a flange cavity portion C4, which are part of the cavity C. As shown in FIG. 18 is after the mold is closed and before the cavity C is filled with the resin. Since the label end 2a is set so that the protruding length along the axial direction is longer than the axial distance between the flange cavity portions C4, the label end portion 2a is projected outward in the radial direction by the flange surface cavity surface 23 of the movable mold 20 when the mold is closed. remain bent. In other words, just before the cavity C is filled with resin, the label end portion 2a is in a bent state so as to approach the flange back cavity surface 13 of the fixed mold 10 . The label pressing portion 30 can accommodate the label end portion 2a in the cavity C without causing wrinkles even when using a label 2 longer than the conventional one. 19 is a partially enlarged cross-sectional view showing a state in which the cavity C is filled with molten resin from the state of FIG. 18. FIG. At this time, by filling the cavity C with molten resin from the injection device 40 of the injection molding machine 100, the label edge 2a already bent to approach the flange back cavity surface 13 of the fixed mold 10 as described above is , spread along the flange back cavity surface 13 of the stationary mold 10 without wrinkles. Therefore, the back surface 204a of the flange 204 of the in-mold label container 201 can be covered with the in-mold label 2 more widely, and the oxygen barrier property of the container 201 can be improved. In this embodiment, the label end portion 2a of the label 2 is bent along the flange back cavity surface 13 and the flange end back cavity surface 14 of the fixed mold 10 by resin filling. As a result, the entire rear surface 20a of the flange 204 of the in-mold label container 201 is covered with the label 2, and the oxygen barrier property of the container 201 is enhanced.

REFERENCE SIGNS LIST 1 mold device for molding in-mold label container 2 label 2a label end 10 fixed mold (first mold)
10a Fixed mold catty surface (first cavity surface)
REFERENCE SIGNS LIST 12 Cavity surface outside peripheral wall 13 Cavity surface behind flange 14 Cavity surface behind flange end 20 Movable mold 20A Core 20B Stripper 20a Fixed mold cavity surface (second cavity surface)
22 Peripheral wall inner cavity surface 23 Flange front cavity surface 26 Accommodating portion 27 Rod guide 30 Label pressing portion 30M Moving mechanism 31 Label pressing member 31L Label pressing surface 31M Fixed mold contact surface 31A First label pressing surface 31B Second label pressing surface 32 Connection Rod 33 Slide member 34 Radial direction guide 35 Extruder 40 Injection device 50 Moving device 60 Mold clamping device 70 Ejector device 80 Label supply unit 90 Container take-out unit 100 Injection molding machine 103 In-mold label container injection molding system 104 In-mold label container molding System 201 In-mold label container 202 Bottom wall 203 Peripheral wall 204 Flange 204a Rear surface of flange C Cavity C3 Peripheral wall cavity C4 Flange cavity S Space

Claims (6)

An in-mold label comprising a bottom wall, a peripheral wall, a flange protruding outward from an end of the peripheral wall opposite the bottom wall in the axial direction, and an in-mold label integrated with the outer peripheral surface of the peripheral wall. An in-mold label container molding mold device for injection molding a container,
The mold device
a mold comprising a first mold having a first cavity surface and on which the in-mold label is set; and a second mold having a second cavity surface;
a label pressing unit that presses the in-mold label set in the first mold against the first cavity surface side of the first mold during mold closing of the mold;
The label pressing section includes a label pressing member and a moving mechanism,
The mold apparatus for molding an in-mold label container, wherein the moving mechanism moves the label pressing member so that the in-mold label is pressed against the first cavity surface side of the first mold. An in-mold label comprising a bottom wall, a peripheral wall, a flange protruding outward from an end of the peripheral wall opposite the bottom wall in the axial direction, and an in-mold label integrated with the outer peripheral surface of the peripheral wall. An in-mold label container molding mold device for injection molding a container,
The mold device
a mold comprising a first mold having a first cavity surface and on which the in-mold label is set; and a second mold having a second cavity surface;
a label pressing unit that presses the in-mold label set in the first mold against the first cavity surface side of the first mold during mold closing of the mold;
The mold device for molding an in-mold label container, wherein the label pressing section transfers the pressing of the in-mold label to the first mold side to the second mold. the second cavity surface of the second mold includes a flange front cavity surface corresponding to a surface of the flange opposite to the peripheral wall side;
3. The mold device for molding an in-mold label container according to claim 1, wherein the flange surface cavity surface of the second mold takes over the pressing of the in-mold label against the first mold from the label pressing portion. . The mold is closed by moving the second mold with respect to the first mold,
The label pressing unit moves in the mold closing direction in synchronization with the movement of the second mold, and presses the in-mold label set in the first mold against the first cavity surface side of the first mold. The mold device for molding an in-mold label container according to claim 1 or 2 . An in-mold label comprising a bottom wall, a peripheral wall, a flange protruding outward from an end of the peripheral wall opposite the bottom wall in the axial direction, and an in-mold label integrated with the outer peripheral surface of the peripheral wall. An in-mold label container molding method for molding a container using a mold,
The mold comprises a first mold having a first cavity surface and a second mold having a second cavity surface,
The method includes the step of pressing the in-mold label set in the first mold against the first cavity surface side of the first mold during closing of the mold;
A method for molding an in-mold label container, comprising a step of transferring the pressing of the in-mold label to the first mold side to the second mold. the second cavity surface of the second mold includes a flange front cavity surface corresponding to a surface of the flange opposite to the peripheral wall side;
6. The in-mold label container molding method according to claim 5 , wherein the flange front cavity surface of the second mold takes over the pressing of the in-mold label to the first mold side.

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