JPH05253966A - Apparatus for producing multilayered thin-walled container - Google Patents

Abstract

PURPOSE:To economically produce a thin-walled container having a multilayered structure without collapsing layered constitution while reducing the generation of scrap as low as possible. CONSTITUTION:An injection molding machine equipped with a pair of molds is arranged on an injection molding stage A. At the time of mold clamping, an injection space is formed between molds. A sheet piece supply device 70 punches a long sheet material 3 to form one sheet piece and applies the sheet piece to either one of the molds in the injection molding machine before mold clamping. After mold clamping, a resin is injected in the injection space to produce a preform having a multilayered structure wherein an injection resin layer is laminated to the sheet piece. The preform receives plug assist molding processing in a container molding stage C to obtain an objective product container having a multilayered thin-walled structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container manufacturing apparatus for manufacturing a multi-layer thin-walled container made of a resin material having a plurality of resin layers.

[0002]

2. Description of the Related Art A container for packaging food or the like has some of the following properties: mechanical strength, gas barrier property, moisture resistance, heat resistance, and aroma retention. Everything is required. It is known that each of these properties is achieved by a specific resin material.
When there are a plurality of desired properties as necessary, one container is formed by laminating individual resin materials that achieve those properties.

As a method of manufacturing such a multi-layered container, various methods as described below have already been proposed.

The first method is a so-called sheet forming method such as vacuum forming, pressure forming and plug assist forming. This sheet molding method, as shown in FIG.
The belt-shaped sheet 101 is conveyed in the direction of arrow A at a predetermined feed pitch while being heated by the heater 102, and then the container 105 is formed by the dies 103 and 104 arranged so as to face each other. is there.

In this sheet forming method, a large margin portion is formed between the individual containers 105 according to the sheet feeding pitch, and due to the structure of the molds 103 and 104, the sheet feeding direction A is orthogonal to the individual sheets. A large margin is formed between the containers 105 of the above. These margins are very uneconomical because they are so-called scraps that do not contribute as products.

[0006] Such scrap is collected, and the sheet 1
It is also practiced to reuse the sheet 101 by reusing it as a part of the layer structure of No. 01, and to manufacture the container 105 from the recycled sheet. However, in this method, the resin forming the sheet 101 gradually deteriorates due to crushing at the time of reproduction, heat at the time of extruding the sheet, and the like, causing problems such as coloring, a strange odor, and strength deterioration. That is, when scrap is to be reclaimed, a part of the layers of the sheet 101 is configured by a scrap layer or a scrap mixed layer. Since the composition of the scrap of the sheet 101 in which a large amount of such a resin is reused is changed each time it is reclaimed, the characteristics of the sheet 101 as a whole are changed, and the performance of each molded container may vary. is there.

Further, it is extremely difficult to manufacture the sheet 101 to have a uniform thickness, and inevitably the thickness becomes uneven. That is, a film is generally formed by an inflation method, an extrusion method, a co-extrusion method, etc.
The thickness has a certain degree of variation, and it is extremely difficult to make the thickness of a multi-layered sheet uniform. If the thickness of the sheet 101 is uneven,
With respect to the containers 105 formed by the molds 103 and 104, the thickness distribution in one container 105 becomes non-uniform, and the thickness among the containers 105 becomes non-uniform. Further, in forming the sheet, the sheet 101 is heated and softened to form the container. However, the heating temperature of the heater is not uniform in the width direction of the sheet 101, and the cooling condition of the mold is not uniform in each cavity. If there is, the unevenness of the thickness within and between the containers is promoted. Such variations in wall thickness, especially when the container is thinner than the specified size, the mechanical strength of the container (eg, buckling strength) may not be sufficient, or heat sterilization after filling the contents At times, defects such as deformation of the container occur.

As a second example of the method for producing a multilayer structure container, there is a method disclosed in Japanese Patent Publication No. Sho 57-1415. This method heats a rectangular multi-layer sheet material,
Further press-molded to produce a disc-shaped preform,
Further, the disk-shaped preform is molded by vacuum molding or the like to manufacture a product container.

According to this method, scrap can be considerably reduced as compared with the above-described sheet forming. However, when a multilayer sheet material is press-molded to form a preform, it is necessary to heat the sheet material to a high temperature to reduce its viscosity. In this way, the layer structure of the multilayer sheet material is likely to collapse. That is, the layer is partially thinned or easily divided. A product container made of a multi-layer sheet material having a broken layer structure cannot obtain a desired specific function such as gas barrier property.

Further, a good preform cannot be obtained unless a resin having good fluidity is used as a resin in contact with a mold for molding the preform. That is, the resin that can be used as the multilayer sheet material is limited to a narrow range.

A method of manufacturing a container using a preform is disclosed in JP-A-60-178020 and 60-1985.
244518, 63-130330 and 63-
There is a so-called injection blow method disclosed in each publication of 296921. In this injection blow method, a disc-shaped preform is molded by injection molding, and the preform is molded by plug-assist molding or the like to mold a container.

In the injection blow method, since the injection molding method, that is, the injection molding method is used in the step of molding the preform, it is extremely difficult to form the preform into a multi-layer structure. Only the preform of is made. Therefore, there is a problem that a container having a specific function such as gas barrier property cannot be manufactured.

In the case of molding a preform by utilizing injection molding, as shown in, for example, Japanese Patent Laid-Open No. 3-176126, molding with a plurality of injection devices and a multi-layer molding injection nozzle will produce a multi-layered structure. Reforms can be manufactured. In this case, the layer structure is symmetrical, and studies are being conducted toward the practical application of cup-shaped containers and bottles having a gas barrier resin as an intermediate layer. However, according to this technique, it is extremely difficult to make the thickness of each resin layer uniform, and in many cases, the multilayer structure itself does not hold in the vicinity of the cavity end where the fluidized resin finally reaches. Therefore, it is not possible to provide a uniform multilayer structure throughout the preform. Further, this method cannot be applied when a large number of resins need to be laminated in an asymmetrical layer structure as in the present invention.

As another method for producing a multi-layer structure container, Japanese Patent Laid-Open No. 2-45352 and Japanese Utility Model Application Laid-Open No. 2-80519 are available.
There is a method disclosed in each publication of the issue. In this method, a cup-shaped container is preformed by sheet molding, and an outer layer is formed on the outer periphery by injection molding to manufacture the container.

In injection molding, a resin is poured into a gap between molds, and if the gap does not have a certain thickness or more, sufficient molding cannot be performed. Therefore, the above conventional method has a problem that the thickness of the container wall of the completed container becomes too thick.

[0016]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned various problems, and has a multi-layered structure and a thin-walled container without breaking the layered structure. Moreover, it is an object of the present invention to reduce the generation of scrap as much as possible and to enable economical manufacturing.

[0017]

In order to achieve the above object, the apparatus for manufacturing a multi-layer thin-walled container according to the present invention is provided with a pair of molds forming an injection space, and a resin is injected into the injection space. Injection molding means for manufacturing a preform by
A product obtained by punching out a sheet piece from a sheet material and attaching the sheet piece to any of the molds in the injection molding means, and a preform manufactured by the injection molding means It has a container forming means for manufacturing a container.

In the above-mentioned structure, the sheet element and hence the sheet material include a resin layer having a specific function such as gas barrier property, moisture proof property, heat resistance, and aroma retaining property (non-adsorbing property). An adhesive layer, which is provided between the respective layers when the resins having poor adhesiveness are laminated, and which acts as an adhesive, is also considered as a resin layer having a specific function. As the resin layer for achieving each of these functions, the following resin layers can be applied.

Gas barrier property: Saponified ethylene-vinyl acetate copolymer (EVOH), polyvinylidene chloride (PV
DC), polyvinyl alcohol (PVA) Moisture proof: polyamide (nylon), polypropylene (P
P), polyolefin mixed with desiccant Heat resistance: Polyester (PET), Polycarbonate (PC), PP Fragrance retention: PET, EVOH, Polyacrylonitrile (P
AN) Adhesive layer: ionomer, ethylene-vinyl acetate copolymer (EVA)

As the forming process, vacuum forming, pressure forming, plug assist forming and the like can be considered. in this case,
The vacuum forming is a forming method in which the inside of the cavity is evacuated and the sheet material is deformed so as to be in close contact with the mold and formed. Pneumatic molding is a molding method in which a sheet material is pressed by air and brought into close contact with a mold to mold the sheet material.
The plug assist molding is a molding method in which the sheet material is auxiliary pressed by a plug in the above vacuum molding or pressure molding to mold the sheet material.

The resin injected into the injection space in the injection molding means mainly gives the container mechanical strength, and for example, PP, polystyrene, PET, vinyl chloride or the like is used.

[0022]

When manufacturing a multi-layer thin-walled container, first, one sheet material containing one or more resin layers is prepared, and the sheet material is punched by a sheet element supply means to produce a sheet element having a predetermined shape. To do. Then, the sheet piece is attached to one of the molds in the injection molding means. Then, an injection resin layer such as polypropylene (PP) is laminated on the sheet piece by injection molding to manufacture a preform. Then, the product container is manufactured by subjecting the preform to forming processing.

Since press molding is not used for manufacturing the preform, the layer structure of the sheet element, that is, the layer structure of the preform is not broken. Since the preform is formed by the combination of preformed sheet pieces and injection molding, even if there is some variation in the thickness of the sheet pieces, the variation is absorbed by the injection molding, and the preform as a whole The thickness of can be made extremely uniform. Therefore, it is possible to manufacture a container having a uniform thickness. Even in that case, the layer structure inside the container wall does not collapse.

Since a preform is prepared one by one and molded into a product container, scrap is not generated unlike the conventional sheet molding method, and therefore it is very economical. In this case, a large number of sheet pieces themselves to be mounted on the mold are prepared by punching out, ie, cutting, one large sheet material. At this time, the punching of the sheet can be performed at an extremely high density, so that a large amount of scrap does not occur. Further, when the resin layer is laminated by injection molding, almost no scrap is generated. The generation of scrap will be extremely small.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of an apparatus for manufacturing a multi-layer thin-walled container according to the present invention as viewed from above. This device is, for example, as shown in FIG.
Used to manufacture. This container 1 has a winding flange 2 for tightening a sealing metal lid (not shown), and the metal lid is wound around this flange 2 to seal the inside of the container. To be done. It is known that a sufficient sealed state cannot be obtained unless the thickness of the container flange is set to a predetermined thin value at the time of this winding. The preferred thickness of the flange is 0.4-0.6 mm, more preferably 0.4-0.5 mm. When sealing a flanged container manufactured by conventional sheet molding by winding, most of the flanges are too thick, so the flange part is hot pressed, or secondary processing such as scraping the flange part is performed, It has a predetermined thickness.

FIG. 2 is a sectional view taken along the arrow II in FIG. As shown in FIG. 1 and FIG. 2, the container manufacturing apparatus is provided with a disk-shaped base 10, three tie rods 11 fixed to the base 10 and extending upward, and fixed to the upper ends of the tie rods 11. And a disc-shaped top plate 12. A hydraulic press device 13 is fixedly installed on the right side portion of the top surface of the top plate 12. The hydraulic press device 13 drives the output rod 14 to reciprocate linearly in the vertical direction. A mold clamping plate 15 is fixed to the lower end of the output rod 14. The mold clamping plate 15 is loosely fitted to the tie rods 11 and these tie rods 1
It is designed so that it can be translated in the vertical direction by being guided by 1.

In FIG. 2, a disk-shaped movable plate 16 is provided below the mold clamping plate 15. The movable plate 16 is loosely fitted to the tie rods 11 and guided by the tie rods 11 so that the movable plate 16 can move in parallel in the vertical direction. In addition, the movable plate 1
6 is supported at an intermediate position of the tie rod 11 by a supporting device 17 provided corresponding to each of the three tie rods 11. The supporting device 17 is composed of a cylindrical housing 18, a flange 19 formed on the outer peripheral surface of the tie rod 11, and a compression spring 20 arranged between the flange 19 and the movable plate 16. The movable plate 16 is supported by the spring force of the spring 20.

A rotary drive device, for example, an electric motor 21 is fixedly installed at the central position of the movable plate 16. An output shaft 21a of the electric motor 21 penetrates the movable plate 16 and is fixed to a rotary plate 22 provided below the movable plate 16. The outer peripheral side surface of the rotary plate 22 is supported by a ring-shaped support member 23 having an L-shaped cross section fixed to the bottom surface of the movable plate 16.

On the bottom surface of the rotary plate 22, two split molds 24 are joined to each other while being held by the holding member 30.
A preform holding mold 25 including a and 24b is provided. An air cylinder 24d is attached between the split molds 24a and 24b. By the operation of the air cylinder 24d, the split molds 24a and 24b are
It can move in the radial direction, that is, in the left-right direction in FIG.

As shown in FIG. 1, the preform holding molds 25 are provided at four places with a 90 ° interval. These four preform holding molds 25 are driven by the motor 21 and intermittently rotate counterclockwise at intervals of 90 °. The four positions at which these preform holding molds 25 stop during this intermittent rotation are set as an injection molding stage A, a preform heating stage B, a container molding stage C, and a container recovery stage D, respectively.

(Injection Molding Stage) FIG. 2 shows the injection molding stage A. In the injection molding stage A, a substantially cylindrical cavity base 27 is fixedly installed on the base 10 via a block 26, and the injection cavity 2 is attached to the upper end of the cavity base 27.
8 is fixed. Reference numeral 29 is a ring-shaped cavity retainer. A hot runner 32 heated by a band-shaped heater 31 is stored inside the cavity base 27. The tip of the hot runner 32 is in contact with the lower end of the gate 64 of the injection cavity 28. The nozzle tip of the injection molding machine 33 is connected to the hot runner 32, and the injection resin sent from the injection molding machine 33 is supplied to the gate 64 through the hot runner 32.

A columnar injection core 34 fixed to the bottom surface of the mold clamping plate 15 is provided at an upper position facing the injection cavity 28 with the movable plate 16 interposed therebetween. Inside the core 34, a cooling liquid passage 35 and an air suction passage 36 are provided. Cooling water is supplied to the cooling liquid passage 35 from, for example, a water supply source (not shown). A vacuum pump (not shown) is provided in the air suction passage 36.
The air is sucked from the lower end of the core 34 through the air suction passage 36 by the action of the pump.

The injection core 34 is adapted to reciprocate linearly in the vertical direction together with the mold clamping plate 15, and moves between the open position shown in the drawing and the mold clamping position shown in FIG. The open position is a position where the core 34 is largely separated from the cavity 28. Further, the mold clamping position is a position where the core 34 and the cavity 28 are joined to each other and an injection space G corresponding to a desired preform shape is formed therebetween.

A cylindrical guide rod 37 is provided on the left side of the injection core 34. The guide rod 37 has its upper end fixed to the mold clamping plate 15, and further has its lower end fixed to the movable plate 16 and the rotary plate 2.
2, and fits into the through hole 38 provided in the holding member 30 with a slight gap.

In FIG. 1, a sheet element supply device 70 is arranged on the right side of the injection molding stage A. As shown in FIG. 8, the sheet element supply device 70 includes a sheet punching device 71 and a sheet conveying device 72. The sheet punching device 71 includes a lower die 74 fixedly installed on a bottom portion of a frame 73 and a top plate 7 of the frame 73.
It has a punching air cylinder 75 fixed to 3a, and an upper mold 76 connected to the lower end of the output shaft 75a of the air cylinder 75. A cushion material 77 is adhered to the bottom surface of the upper mold 76.

The sheet conveying device 72 has an elevating air cylinder 79 fixed to a top plate 78a of a frame 78, an elevating plate 80 fixed to a lower end of an output shaft 79a of the air cylinder 79, and fixed to the elevating plate 80. The air cylinder 81 for forward and backward movement and the head unit 82 fixed to the tip of the output shaft 81a of the air cylinder 81. The head unit 82 includes a disk-shaped cushion material 83 when viewed from above in the drawing, a ring-shaped extraction blade 84 which is embedded in the cushion material 83 when viewed from above in the drawing, and an air suction tube 85. Have

(Preform heating stage) FIG. 4 shows the preform heating stage B according to the arrow IV in FIG. Base 10 at this stage B
Is provided with a sprue cutting device 39 at the left end thereof. The sprue cutting device 39 is fixed to an air press device 40 fixed to the base 10, two guide rods 41 extending obliquely upward from the air press device 40, and a tip of an output rod 40a of the air press device 40. Air nippers 4 that move vertically by being guided by the guide rod 41.
2 and. At the tip of the air nipper 42, a nipper 43 that is driven by air to open and close is provided. Reference numeral 44 is a column for supporting the guide rod 41.

An elevating device 45 driven by hydraulic pressure or pneumatic pressure is fixedly installed on the bottom surface of the base 10 at a position centered from the air press device 40. The lower heater unit 4 is attached to the upper end of the output rod 45a of the lifting device 45.
6 is fixed. This lower heater unit 46 is
The heating pot 47 has a substantially columnar shape, a band-shaped heater 48 wound around the outer peripheral side surface of the heating pot 47, and a clamp head 49.

An upper heater unit 50, which is fixed to the bottom surface of the mold clamping plate 15 and hangs down, is provided at an upper position facing the lower heater unit 46 with the movable plate 16 interposed therebetween. The upper heater unit 50 is a substantially columnar main body 53 fixed to the bottom surface of the mold clamping plate 15.
A heating core 51 fixed to the main body 53 with bolts or the like (not shown), a band-shaped heater 52 wound around the outer peripheral side surface of the heating core 51, and a rod-shaped heater extending through the main body 53 to the heating core 51. 54 and.

(Plug Assist Molding Stage) FIG.
The container molding stage C is shown according to the arrow VI in FIG. On this stage C, a plug assist molding apparatus including an upper mold unit 56 and a lower mold unit 57 is installed. The lower die unit 57 is fixed to the upper end of an output rod 55a of an elevating device 55 driven by hydraulic pressure or air pressure fixedly installed on the bottom surface of the base 10. This lower mold unit 57 is used for the product container 1
Lower container mold 5 having a recess Q conforming to the shape of (FIG. 15)
8, a lower die holder 59 accommodating the container lower die 58, and a cooling cylinder 60 for cooling the container lower die 58.

Lower mold unit 5 with the movable plate 16 in between.
The upper mold unit 56 provided so as to face the upper mold 7 includes a substantially cylindrical upper mold core 61, a plug 62 that extends vertically through the upper mold core 61, and an air introduction formed around the plug 62. And a hole 63. The air introduction hole 63 is connected to an air supply source (not shown), and the air sent from the air supply source is jetted downward from the lower end of the upper die core 61 through the air introduction hole 63.

(Container Recovery Stage) In FIG. 1, a container recovery stage D is provided for separating the mold halves 24a and 24b forming the preform holding mold 25 from each other by switching the operation direction of the air cylinder 24d. Mechanism is installed. Any structure can be adopted as the structure of the separating mechanism.

The operation of the container manufacturing apparatus having the above structure will be described below.

(Manufacturing and Supplying Process of Sheet Piece) First,
As shown in FIG. 2, the mold clamping plate 15 is lifted up to the uppermost position by the hydraulic press device 13, and the injection core 34 and the preform holding mold 25 are both released from the injection cavity 28 at the open position (state shown in the drawing). ) To. As a result, the upper surface of the cavity 28 is largely opened.

In this state, in FIG. 8, the head unit 82 is placed on the lower die 74 of the sheet punching device 71. The head unit 82 is previously formed on the upper surface of the lower mold 74.
An escape groove for accommodating the air suction pipe 85 protruding downward is formed. The long sheet material 3 is inserted between the head unit 82 and the upper mold 76. The sheet material 3 includes a resin layer having a gas barrier property and other specific functions. With the head unit 82 placed on the lower die 74, the punching air cylinder 75 operates and the upper die 76 descends.

The upper mold 76 that descends presses the sheet material 3 against the punching blade 84 while sandwiching the sheet material 3 in cooperation with the cushion material 83. As a result, one circular sheet piece 5 as shown in FIG. 13 is punched out from the sheet material 3. This sheet piece 5 also includes, of course, a resin layer having a gas barrier property and other specific functions. The punched sheet piece 5 is attached by being sucked by the air flowing through the air suction pipe 85 and in close contact with the cushion material 83.

Thereafter, the lifting plate 80 and the air cylinder 8 fixed thereto are lifted by the lifting air cylinder 79.
1 is lifted upwards. As a result, the head unit 82 is lifted above the lower mold 74. When the head unit 82 to which the sheet element 5 is attached is lifted in this way, the air cylinder 81 operates and its output shaft 81
a moves forward to the left in the drawing, and conveys the head unit 82 to a position below the injection core 34. After that, the air cylinder 81 is lifted by the lifting air cylinder 79.
Therefore, the head unit 82 is lifted upward, and the sheet piece 5 adsorbed on the cushion material 83 comes into close contact with the lower end surface of the injection core 34. When the sheet piece 5 comes into close contact with the injection core 34, the flow of air in the air suction pipe 85 switches from the suction direction to the blowing direction. As a result, the sheet piece 5 is sucked by the air flowing through the air suction passage 36 on the injection core 34 side and sucked and held by the lower end of the core 34.

When the sheet piece 5 is attached to the lower end of the injection core 34, the lifting air cylinder 7 is lifted.
The air cylinder 81 for front-rear movement is lowered by being driven by 2, and the output shaft 81a of the air cylinder 81 is returned to the right direction, whereby the head unit 82 is set again on the lower die 74 in the sheet punching device 71. It While the head unit 82 is conveyed as described above, the unpunched portion of the sheet material 3 is sent to the position above the lower mold 74.

(Injection molding step) When the above-mentioned sheet element manufacturing and supplying steps are completed, the disk-shaped sheet element 5 is attached to the lower end of the core 34, as shown in FIG. The sheet piece 5 is adsorbed and fixed to the lower end of the core 34 by the air flowing through the air suction passage 36. The upper surface of the mounted sheet element 5, that is, the surface in contact with the core 34, is the inner peripheral surface of the container.

When the sheet piece 5 is attached to the lower end of the core 34, as shown in FIG. 3, the hydraulic press device 13 operates to press the mold clamping plate 15 downward. The mold clamping plate 15 to be pressed has a movable plate 1 depending on its bottom surface.
Push down 6. The movable plate 16 pushed down stops when the holding member 30 hits the upper end of the stopper 65. In this stopped state, as shown in FIG.
4 and the preform holding mold 25 are set at the mold clamping position. That is, the core 34, the preform holding mold 25, and the cavity 28 are used to form the preform 7
An injection space G having a shape (see FIG. 14) is formed. In this state, the resin is poured into the injection space G via the hot runner 32. As a result, the injection resin layer 6 (see FIG. 14) is laminated on the lower surface of the sheet element 5 and the injection resin layer 6 shown in FIG.
The preform 7 shown by the solid line in FIG. 4 is formed.

When the preform 7 is formed, as shown in FIG.
5 is lifted up, and the movable plate 16 is lifted up by the spring force of the spring 20 in the support device 17 supporting the movable plate 16. As a result, the upper part of the cavity 28 is opened. When the upper part of the cavity 28 is opened in this way, the motor 21 is operated and the rotary plate 22 is rotated 90 ° counterclockwise in FIG.
By this rotation, the holding mold 25 holding the manufactured preform 7 is carried to the next preform heating stage B.

(Preform heating step) When the injection molding is completed, the preform 7 is then divided into the split molds 24a, 2a.
While being held by the holding die 25 composed of 4b,
It is sent to the preform heating stage B. As shown in FIG. 4, when the holding mold 25 holding the preform 7 is set at a predetermined position in the heating stage B, first,
The mold clamping plate 15 descends and the upper heater unit 50
Moves down, the movable plate 16 is pushed down, and the holding mold 25 moves down. And sprue cutting device 3
The air press 40 in 9 operates to lift the air nipper 42 to the upper position shown by the chain line. The air nipper 42 lifted to the upper position cuts the sprue portion 7a hanging downward from the central portion of the preform 7 from its root portion by the nipper 43 arranged at the tip thereof. The cut sprue portion 7a is discharged downward through the guide plate 66.

When the cutting process of the sprue portion 7a is completed,
The air nipper 42 is pulled back to the lower position (solid line). Then, the elevating device 45 operates, and as shown in FIG. 5, the lower heater unit 46 is lifted upward and fitted to the outer periphery of the lower end of the preform holding mold 25. By the above operation, as shown in FIG. 10, the upper heater unit 50 is carried out to a position directly above the preform 7, and the lower heater unit 46 is carried out to a position below the preform 7. The preform 7 is heated by the heat radiated from the upper heater unit 50 and the lower heater unit 46. By this heating, fusion of the sheet element 5 and the injection resin layer 6 is promoted, and preheating for the next step, that is, the container forming step is performed. This process is
It may be omitted in some cases.

When the heating process is completed, as shown in FIG. 4, the mold clamping plate 15 is lifted up, the upper heater unit 50 is lifted up, and the elevating device 45 is moved back to move the lower heater unit 46. Can be lowered downwards. As a result, the periphery of the holding mold 25 holding the preform 7 is largely opened. Under this open state, the motor 21 operates and the rotary plate 22 further rotates 90 ° counterclockwise in FIG. 1 to convey the preform 7 to the container forming stage C.

(Container Molding Step) The preform 7 which has undergone the preform heating step is then sent to the container molding stage C (FIG. 6) while being held by the holding mold 25. When the mold 25 holding the preform 7 is set at a predetermined position, the mold clamping plate 15 descends, the upper mold unit 56 descends, and the movable plate 16 is pushed by the mold clamping plate 15 and descends. Accordingly, the holding mold 25 descends. In addition, the upper die unit 56
At the same time when the holding mold 25 is lowered, the elevating device 55 is activated and the lower die unit 57 is raised. As a result, as shown in FIG. 7, the outer periphery of the lower end of the preform holding mold 25 is fitted to the upper end of the lower mold unit 57. Thus, the upper mold core 61 including the plug 62 is set at a predetermined container molding position from above the preform 7. At this time, FIG.
As shown in FIG. 5, the outer edge portion C of the preform 7 is sandwiched and fixedly supported by the holding mold 25, the upper mold core 61 and the container lower mold 58.

In this state, the container forming process, that is, the plug assist forming process is executed. That is, the reciprocating linear drive device 67 (FIG. 7) which is operated by hydraulic pressure or air pressure is operated to lower the plug 62, the preform 7 is pressed downward by the plug 62, and thereafter or simultaneously, the air passes through the air introduction hole 63. The preform 7 is extended by the air that is sent in. The preform 7 thus extended is formed into a wall shape of the recess Q of the container lower die 58, that is, a cup shape, and as a result, the product container 1 having a shape as shown in FIG. 15 is completed.

When the product container 1 is formed, as shown in FIG. 6, the upper mold unit 56 is lifted and the lower mold unit 57 is lowered, so that the surroundings of the holding mold 25 holding the product container. Be released. After that, the rotary plate 22 is rotated 90 ° counterclockwise in FIG.
5, that is, the product container 1 is transported to the container collection stage D.

(Container collecting step) As shown in FIG. 1, in the container collecting stage D, the split molds 24a and 24b constituting the holding mold 25 are driven by the air cylinder 24d, and as shown by an arrow E. , Move away from each other in the radial direction. This movement is indicated by arrow F in FIG.
Corresponds to translation in the direction. By this movement, the product container is dropped from both molds 24a and 24b and collected.

(Post-Processing Step) It is also possible to cut the product container 1 along the line XX or YY in FIG. 14 by using a cutting device (not shown). In this case, if the cutting device is provided in the container lower die 58 of the container molding stage C (FIG. 6) or in the vicinity thereof, the container can be cut immediately after the container molding is completed. Of course, the lower container mold 58
After removing the product container from the container, the container may be separately cut.

Although one embodiment has been described above,
The following modifications can be made to the example.

The shape of the product container can be any shape (for example, a rectangular tray shape) other than the winding cup shape shown in FIG. In this case, it is obvious that the shape of the sheet element 5 (FIG. 13) is prepared in a shape corresponding to the shape of the product container.

The shape of the product container is as shown in FIG.
It may be in the shape of a cup for heat sealing. The heat-sealing cup container 8 has a heat-sealing flange 9 for heat-sealing a thin-plate heat-sealing lid (not shown) for sealing, and the heat-sealing lid is heat-welded to the flange 9. The inside is sealed. In this case, the heat-sealing flange 9 needs to have a thickness that can withstand the heat and pressure during the heat-sealing work of the heat-sealing lid.
Also, by appropriately considering the size and thickness of the injection resin layer 6, the heat-sealing flange 9 suitable for the purpose can be obtained.

If necessary, the injection molding process can be repeated a plurality of times to form two or more injection resin layers 6. Further, in the above embodiment, the preform 7
Although the sheet element 5 side is formed so as to be the inner surface of the product container 1, the injection resin layer 6 side may be the inner surface of the product container 1.

Further, in the above-mentioned embodiment, the sheet element 5 is used as the inner surface side of the container, but this has the following advantages. That is, the material that can be suitably used for the sheet element 5 is a material having a specific function, such as a saponified ethylene-vinyl acetate copolymer that is a gas barrier resin or a polyester resin that is a non-adsorptive resin, On the other hand, since the resin of the injection resin layer is a resin such as polypropylene that is a main structural material of the container, the resin of the injection resin layer is generally more suitable for molding into a container shape such as sheet molding. Therefore, by arranging the sheet piece 5 on the inner surface side of the container during the sheet forming, it is possible to prevent the sheet piece 5 from being formed defectively (thickness variation, cracking due to insufficient elongation during sheet forming). ..

When a non-adsorptive resin is used for the sheet piece 5, this resin can achieve its purpose only when it is placed in a position in contact with the contents, so that it is manufactured in the positional relationship as in the above embodiment. Preferably.

FIG. 17 shows an injection molding apparatus capable of simultaneously carrying out both the steps of manufacturing and supplying sheet pieces and the injection molding step. This apparatus is used instead of the injection molding apparatus shown in FIG. This injection molding device has a pair of metal molds, that is, an upper mold 86 and a lower mold 87, which are roughly opposed to each other. In the upper mold 86 and the lower mold 87,
Since the members denoted by the same reference numerals as those used in FIG. 9 are the same members, the description thereof will be omitted.

The inner peripheral edge 24c of the lower end of the split molds 24a and 24b for holding the preform and the outer peripheral edge 28a of the upper end of the protruding portion of the injection cavity 28 are punched portions for shearing the strip-shaped sheet material 3 present therebetween. 88. Inner peripheral edge 24c of split molds 24a, 24b
And the outer peripheral edge 28a of the injection cavity 28 is
When the upper die 86 and the lower die 87 are clamped together, that is, when they are joined together under pressure, they fit each other without a gap, and during the fitting, a shearing force acts on the sheet material 3 existing between them. The sheet material 3 is sheared at the punch portion 88.

A sheet material supply device 89 is provided on the left side of the present injection molding device, and a sheet material winding device 90 is provided on the right side thereof. The film-shaped sheet material 3 delivered from the sheet material supply device 89 is conveyed in the direction of arrow B, passes between the upper mold 86 and the lower mold 87, and is wound up by the sheet material winding device 90.

The production and supply of sheet pieces and injection molding are carried out as follows.

As shown in FIG. 17, the upper die 86 is the lower die 87.
The sheet-shaped sheet material 3 is inserted between the two dies 86 and 87 by the sheet material supply device 89 in the open position. After that, the upper die 86 is lowered, and the two dies 86 and 87 are set at the die clamping position as shown in FIG. At this time, the punching portion 88 is fitted, that is, the upper end outer edge 28a of the protruding portion of the cavity 28.
The sheet material 3 is sheared by the fitting between the holding molds 24a and 24b and the inner edges 24c of the lower ends, and is cut into the disc-shaped sheet pieces 5 as shown in FIG. In FIG.
The cut sheet piece 5 is sucked by the air flowing through the air suction passage 36 and fixed to the lower end of the injection core 34 by suction.

Since the subsequent steps are the same as those in the previous embodiment shown in FIGS. 9, 10 and 12, the description thereof will be omitted.

As described above, in this embodiment, when a pair of dies facing each other are clamped during injection molding for manufacturing a preform, a single sheet piece is automatically formed from a film-shaped sheet material. Is made. Therefore, a pre-process for punching out the sheet piece is unnecessary, and the workability is improved. In addition, when a sheet piece is manufactured and then mounted in a mold later, a mounting-dedicated robot is required, which increases costs. On the other hand, the present embodiment is economical because such a dedicated robot is unnecessary.

Further, when a sheet piece is manufactured in advance and then mounted in a mold later, a special mechanism is provided in order to prevent the front and back of the sheet piece from being mistaken. There is a need. On the other hand, in this embodiment, once the front and back of the film-shaped sheet material are determined, the front and back of the sheet element to be punched out are automatically determined, and there is no room for error.

FIG. 19 shows still another embodiment of the injection molding device. In the injection molding apparatus shown here, the outer peripheral surface of the lower end of the injection core 34 and the through hole 16a provided in the movable plate 16 are fitted with each other with almost no gap. Further, the long sheet material 3 is inserted between the bottom surface of the injection core 34 lifted to the uppermost position and the upper surface of the movable plate 16 in the direction perpendicular to the paper surface. When the injection core 34 descends, the sheet material 3 is sheared by the fitting of the injection core 34 and the movable plate 16, and one sheet piece is manufactured.

FIG. 20 shows still another embodiment of the injection molding device. This injection molding apparatus has a movable mold 91 and a fixed mold 92, which are two molds facing each other. The movable mold 91 includes an injection core 34, split molds 24a and 24b, and the like.

The fixed mold 92 is composed of the cavity base 27.
It has an injection cavity 28, and an auxiliary mold 93. On the inner peripheral surface of the auxiliary mold 93, a taper T provided on the lower peripheral surfaces of the split molds 24a and 24b.
A taper T2 having an inclination equal to 1 is provided. The auxiliary mold 9 is provided between the auxiliary mold 93 and the cavity base 27.
One or a plurality of elastic biasing devices 94 for elastically biasing 3 toward the movable mold 91 are provided. The elastic biasing device 94 includes a compression spring 95 provided between the lower surface of the auxiliary mold 93 and the cavity base 27, and the compression spring 95.
And a screw 96 penetrating therethrough. Screw 9
The tip of 6 is screwed to the bottom of the auxiliary mold 93.
The auxiliary mold 93 is elastically biased upward in the drawing by a spring 95, and with the head 96a of the screw 96 in contact with the upper surface of the counterbore hole 97 provided in the cavity base 27, Stand still.

The stationary position of the auxiliary mold 93 is the auxiliary mold 93.
The sheet material receiving surface 93a is the same as the upper end surface of the injection cavity 28, or is set at a position projecting above it. The stationary position of the auxiliary mold 93 can be adjusted by adjusting the screwing length of the screw 96 into the auxiliary mold 93.

At the central portion of the cross section of the auxiliary die 93, that is, at the lowermost position of the taper T2, the sheet material 3 is slightly thicker than its plate thickness, and its width in the direction perpendicular to the paper surface is the direction perpendicular to the paper surface of the sheet material 3. The slit-shaped openings 98, 98 are formed to be slightly wider than the width. The long sheet material 3 stretched between the supply roll 89 and the take-up roll 90 is disposed in proximity to or in contact with the upper end surface of the injection cavity 28 through the opening 98.

The inner peripheral edges of the lower ends of the split molds 24a and 24b constitute outer punch portions 99, and the outer peripheral edges of the upper ends of the injection cavities 28 constitute inner punch portions 100.

The operation of the injection molding apparatus having the above structure will be described below.

First, as shown in FIG. 20, the fixed mold 92 and the movable mold 91 are placed at positions apart from each other, that is, at the open position. In this state, the supply roll 89 and the winding roll 90 rotate, and the unpunched portion of the sheet material 3 is fed to the upper surface of the injection cavity 28. At this time, the sheet material 3 is guided by the slit-shaped opening 98 of the auxiliary mold 93 and is always placed at a fixed position with respect to the injection cavity 28.

After that, the movable mold 91, that is, the injection core 34, the split molds 24a, 24b, and the like move downward, and as shown in FIG. 21, the split molds 24a, 24b.
The lower end of b is fitted into the auxiliary mold 93. At this time, the tapers T1 and T2 are fitted to each other, and the split molds 24a, 2
The outer punch 99 of 4b is guided toward the inner punch 100 of the injection cavity 28.

When the lower end surfaces of the split molds 24a and 24b are in a state of pressing the auxiliary mold 93 via the sheet material 3, the spring force of the spring 95 of the elastic biasing device 94 causes the auxiliary mold 93 and the split molds. The sheet material 3 is sandwiched by 24a and 24b. The holding force with respect to the sheet material 3 can be freely set by appropriately selecting the spring constant or spring stroke of the spring 95.

After the sheet material 3 is thus sandwiched,
The split molds 24a and 24b still move downward. During the movement, the sheet material 3 is sheared by fitting the outer punch portion 99 and the inner punch portion 100, and the disc-shaped sheet element piece 5 as shown in FIG. 13 is produced. The obtained sheet piece 5 is sucked by the air flowing through the air suction passage 36 and adsorbed on the lower end surface of the injection core 34.

After the sheet piece 5 is created, the split mold 2 is formed.
4a and 24b continue to move, and as shown in FIG. 22, the upper end of the injection cavity 28 is inside the split molds 24a and 24b for a predetermined length, that is, the bottom surface of the auxiliary mold 93 is the cavity base. It stops at the position where it abuts the upper surface of 27. This position is the mold clamping position for the injection cavity 28 and the split molds 24a, 24b. At this mold clamping position, an injection space G matching the shape of the preform 7 (FIG. 14) is formed between the split molds 24a and 24b and the injection cavity 28.

When the split molds 24a, 24b and the injection cavity 28 are clamped at the mold clamping position, the resin is injected from the hot runner 32, and the resin is supplied into the injection space G through the gate 64. Thus, the injection resin layer 6 is formed on the lower surface of the sheet element 5 as shown in FIG.
The preform 7 in which the layers are laminated is created. As described above, the preform 7 is then subjected to forming processing by stretch blow molding, for example, vacuum forming, pressure forming or plug assist forming, and a product container having a desired shape is manufactured.

Divided molds 24a, 24b in the movable mold 91.
However, when the state of FIG. 21 shifts to the state of FIG. 22, that is, when the split molds 24a, 24b and the injection cavity 28 shift from the non-fitting state to the fitting state, the lower ends of the split molds 24a, 24b. Is guided by the auxiliary mold 93 and accurately fits into the injection cavity 28. Therefore, the outer punch portion 99 and the inner punch portion 1
No. 00 is fitted into each other accurately without hitting each other, and therefore wear of both punch portions 99 and 100 can be reduced.

FIG. 23 shows a modification of the split molds 24a and 24b and the auxiliary mold 93. The feature of this modified embodiment is that clamping members 68 are provided inside the lower ends of the split molds 24a and 24b in an annular shape or at a plurality of positions on a circular locus, and auxiliary molds are provided so as to face the clamping members 68 or these clamping members 68. The holding member 69 having the same shape and the same material is provided inside the upper end of 93. These holding members 68, 6
9 is provided so as to slightly project from the lower end surfaces of the split molds 24a and 24b and the bottom surface 93a of the auxiliary mold 93. The holding members 68 and 69 are made of a material having a high friction coefficient and elasticity, such as urethane resin.

Outer punch portion 9 of split molds 24a, 24b
9 and the inner punch portion 1 of the injection cavity 28
When punching out the sheet material 3 with 00, the split mold 2
As described above, the sheet material 3 is sandwiched by the bottom surfaces of the sheets 4a and 24b and the sheet material receiving surface 93a of the auxiliary die 93. Split molds 24a, 24b and auxiliary mold 9
In the present embodiment in which the sandwiching members 68 and 69 are provided on the surface facing the sheet 3, the sheet material 3 is sandwiched by the sandwiching members 68 and 69 when the sheet material 3 is punched out. Since the split molds 24a and 24b and the auxiliary mold 93 are usually made of a metal material, there is a possibility that the sheet material 3 cannot be reliably clamped by slippage, but the clamping member 68, which has elasticity with a high friction coefficient, If the sheet material 3 is sandwiched by 69, such slippage of the sheet material 3 does not occur. The sandwiching member may be provided on one of the split molds 24a and 24b and the auxiliary mold 93.

Using the injection molding apparatus of this embodiment, a sheet piece preparation step of punching out a long sheet material to produce a sheet piece and a preform produced by laminating an injection resin layer on the surface of the sheet piece. Both steps of the injection molding process can be performed in one stage by one injection molding apparatus.

In addition to the drive system that generates the mold clamping force,
There is no need to provide a special drive system for punching out the sheet material. As a result, the structure of the injection molding device can be simplified,
In addition, the device can be manufactured at low cost.

When punching out the sheet material, the sheet material is sandwiched under a predetermined pressure by a die having an outer punch portion and an auxiliary die. Therefore, when the sheet material is punched by the outer punch portion and the inner punch portion, the sheet material is not displaced or distorted and can be punched accurately.

[0093]

According to the present invention, the preform is formed by performing the injection molding with the sheet piece punched out from the sheet material mounted in the mold, so that the injection molding can be used. Nevertheless, it is possible to obtain a stable quality multilayer preform.

Since the preforms are formed one by one by injection molding and the product container is formed from the preforms, almost no unnecessary components such as scrap are generated. Therefore, it is very economical.

Since the preform is produced by injection molding instead of press molding, the layer structure in the preform is not destroyed. Therefore, a specific function such as gas barrier property can be surely obtained.

Since injection molding is used, the preform has extremely high accuracy of thickness, and the product container is made by molding the preform of uniform thickness into a container shape. It is possible to make a container having a stable thickness accuracy without variation.

[0097]

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of an apparatus for manufacturing a multi-layer thin-walled container according to the present invention.

FIG. 2 is a side sectional view showing the injection molding apparatus according to the arrow II in FIG.

FIG. 3 is a side sectional view showing a state where the injection molding device of FIG. 2 has moved to a mold clamping position.

FIG. 4 is a side sectional view showing the preform heating device according to the arrow IV in FIG.

5 is a side sectional view showing a state where the preform heating device of FIG. 4 has moved to a mold clamping position.

6 is a side sectional view showing the plug assist molding apparatus according to the arrow VI in FIG.

FIG. 7 is a side sectional view showing a state in which the plug assist molding apparatus of FIG. 6 has moved to a mold clamping position.

FIG. 8 is a side view showing an example of a sheet element supply device.

FIG. 9 is an enlarged view showing a main part of FIG.

FIG. 10 is an enlarged view showing a main part of FIG.

FIG. 11 is an enlarged view of a main part of FIG.

FIG. 12 is an enlarged view showing a main part of FIG.

FIG. 13 is a perspective view showing an example of a sheet element.

FIG. 14 is a cross-sectional view showing an example of a preform.

FIG. 15 is a perspective view showing a winding container which is an example of a multilayer thin container.

FIG. 16 is a perspective view showing a heat-sealing container which is another embodiment of the multilayer thin-walled container.

FIG. 17 is a side sectional view showing another embodiment of the injection molding device.

FIG. 18 is a side sectional view showing a case where the injection molding device of FIG. 17 is in a mold clamping state.

FIG. 19 is a side cross-sectional view showing still another embodiment of the injection molding device.

FIG. 20 is a side sectional view showing still another embodiment of the injection molding device.

21 is a side sectional view showing a case where the injection molding apparatus of FIG. 20 is in a state of sandwiching a sheet material under pressure.

22 is a side sectional view showing a case where the injection molding apparatus of FIG. 20 is in a mold clamping state.

23 is a partial cross-sectional view showing an embodiment in which the injection molding apparatus of FIG. 20 is improved.

FIG. 24 is a perspective view showing an example of a conventional container manufacturing apparatus.

[Explanation of symbols]

 1 Cup Container for Tightening 3 Sheet Material 5 Sheet Element 7 Preform 8 Cup Container for Heat Seal 24a Split Mold 24b Split Mold 28 Injection Cavity 33 Injection Molding Machine 34 Injection Core 70 Sheet Fragment Supply Device A Injection Molding Stage B Preform heating stage C Container molding stage D Container recovery stage G Injection space

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B29C 51/14 7421-4F 69/02 8115-4F B32B 1/02 7016-4F B65D 1/00 B 7445-3E 1/28 7445-3E // B29D 22/00 7344-4F B29L 9:00 4F 22:00 4F (72) Inventor Tetsuo Watada 1-5-1 Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. (72) Inventor Kiyoshi Sawada 1-5-1 Taito, Taito-ku, Tokyo Within Toppan Printing Co., Ltd.

Claims (3)

[Claims] 1. A manufacturing apparatus for a multi-layer thin-walled container made of a resin material having a plurality of resin layers, comprising a pair of molds forming an injection space, and injecting the resin into the injection space. Injection molding means for manufacturing reform, sheet element supply means for punching out a sheet piece from a sheet material, and mounting the sheet piece on one of the molds in the injection molding means, manufactured by the injection molding means An apparatus for manufacturing a multi-layer thin-walled container, comprising container forming means for forming a product container by forming a preform. 2. The apparatus for manufacturing a multi-layer thin-walled container according to claim 1, wherein the sheet piece supply means supplies the sheet pieces to the injection molding means from the outside of the injection molding means. 3. The sheet element supply means is a sheet material supply means for supplying a sheet material between a pair of molds in the injection molding means, and the sheet material supply means is provided in the pair of molds. An apparatus for manufacturing a multi-layer thin-walled container according to claim 1, further comprising a punching punch that cuts to form sheet pieces.