JP4221128B2 - Plastic container thermoforming apparatus and plastic container molded using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic container thermoforming apparatus and a plastic container formed using the same. For example, an electronic component or a mechanical precision component is transported between processes on a production assembly line or transported between offices. Plastic containers such as transport containers to be used, packaging containers for various parts, and packing containers have high rigidity, and the finish of the cut end surface of the leg seat is excellent.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there are, for example, those shown in FIG. 14 and FIG. 15 for plastic molding containers used for transporting electronic components such as semiconductor elements and printed boards and mechanical precision components. FIG. 19 shows a cutting apparatus for cutting from the remaining pieces.
That is, a base plate a and a desired number of vacuum suction holes b installed on the upper surface of the base plate a₁, B₂, B_ThreeB₁, B₂, B_ThreeAre provided in the thickness direction, and a convex portion d for forming a substantially dish-shaped main body portion c of the molded product S ′ on the upper surface, and a desired width t ″ of the molded product S ′ around the convex portion d. A plane substantially annular shape having an inclined surface g on the inner surface on the outer peripheral side in order to form an inclined side wall portion f having a draft angle θ connected to the edge portion e and the upper edge portion e so as to surround the main body portion c. A bottom mold frame i in which a concave portion h is formed, and a concave portion k provided so as to be movable up and down with respect to the bottom mold frame i and corresponding to the convex portion d and the concave portion h.₁And convex part k₂Are formed on the lower molding surface.
In order to mold the plastic transport container m, for example, a heated thermoplastic synthetic resin sheet n is disposed on the upper surface of the bottom mold i, and then the bottom mold i rises, and the pressing mold l becomes the bottom mold. Both move oppositely so as to descend with respect to i. Then the vacuum suction hole b provided in the bottom mold i₁, B₂, B_ThreeB₁, B₂, B_ThreeWhen the vacuum pump (not shown) is driven, the inside of the mold is evacuated with the synthetic resin sheet n as a boundary, and the molded product S ′ is applied by applying pressure to the synthetic resin sheet n from above with the press mold l. Mold. Thereafter, as shown in FIG. 19, the outer periphery of the inclined side wall portion f of the molded product S ′ is cut using a cutting device r constituted by a lower base p equipped with a cutter o and an upper base q for pressurization. A transport container m as a molded product is molded. n ′ is a remaining piece after the transport container m is cut.
[0003]
[Problems to be solved by the invention]
The conventional plastic transport container m formed by the transport container forming apparatus as shown in FIGS. 14 and 15 has a peripheral side wall portion with a mold draft with a synthetic resin sheet n exhibiting flexibility. Since the molding is performed with θ, when the outer periphery of the inclined side wall portion f is cut with the cutters o and o of the cutting device r, the cutting may be performed with an acute angle θ ′ as shown in FIG. For this reason, when the transport container m is placed on the floor surface T as shown in FIG. 16, the play container becomes unstable or unstable, the installation position of the transport container m is not constant, and the robot is used in the production line or the assembly line. It was inefficient because it could not be utilized. In addition, burrs were likely to occur on the cut end face, and the appearance was unusable, resulting in poor finish and poor yield.
Moreover, since the inclined side wall part f is shape | molded with the draft angle (theta) of a metal mold | die, when carrying containers m are piled up at the time of storage after shaping | molding, as shown in FIG. 18, the inclination of the conveyance container m arrange | positioned at an upper stage is shown. The lower surface of the side wall part f is opened with a size larger than the upper edge part e of the transport container m arranged at the lower stage. As a result, the inclined side wall portion f of the upper transport container m is not placed on the upper edge e of the lower transport container m, and the upper and lower transport containers are fitted with the inclined side wall portion f to which the draft portion is attached. Therefore, manual operation is required to separate again. In order to save this trouble, the transport container m cannot be individually moved by an automatic transfer device such as a robot unless the partition plate s is overlapped and interposed on the upper surface of the transport container m located in the lower stage. Therefore, it takes a lot of time and labor to stack the transport containers m in an orderly manner and to easily take out the containers, and an extra part such as a partition plate s is required, and the equipment cost is also expensive. Furthermore, when the components accommodated in the transport container m are relatively heavy, such as a small magnetic storage device, a large weight is applied to the transport container m, and the inclined side wall portion f bends structurally without exhibiting rigidity. It was vulnerable.
The present invention solves the above-mentioned conventional inconvenience, and when the cutting end is used to cut the extended end extending in the substantially horizontal direction below the molded product, the cutting angle is cut to about 90 °, which causes rattling or instability. It is possible to use robots and other automatic transport devices without any burrs, and it has a good appearance and good yield without generating burrs, and it can be stacked quickly and reliably in the desired number of transport containers during storage. As a result, the storage area can be reduced, the facility cost can be reduced, and the rigidity of the side wall can be demonstrated and the plastic container can be molded using a structurally robust thermoforming apparatus and the like. It is intended to provide a plastic container.
[0004]
[Means for Solving the Problems]
  According to a first aspect of the present invention, there is provided a bottom mold frame provided with a vacuum suction hole, and a substantially vertical side wall of the molded product provided around the bottom mold frame so as to be able to advance and retreat in a substantially horizontal direction with respect to the bottom mold frame. A split mold comprising a plurality of side molds which are arranged outwardly in a substantially horizontal direction by a projecting part projecting inward and form an extended end which cuts at a desired position. Thermoforming the molded productRupuPlastic container thermoforming equipmentIn
(A) A planar, generally annular recess that forms the upper edge of the molded product is formed in a desired width on the upper surface of the bottom mold surrounded by the plurality of side molds.,
(B) Around the recess, the protrusion provided on the side moldThe extending end is formed;
(C) Lowering the periphery of the molded product by cutting the extended end with a cutting angle of approximately 90 °AbbreviationHorizontal leg seatFormed,
(D)In the leg seat,A locking step that is detachably locked is provided continuously.ing
(E) It is characterized byAdopted the means that.
[0005]
Further, according to claim 2 of the present invention, in the first aspect, the molded product is heated and molded in a vacuum state in the mold in a substantially bottomed box shape, or one of the interiors of the molded product is bounded by the molded product in the mold. A means was adopted in which the other inside was formed into a vacuum state in a vacuum.
[0006]
  The third aspect of the present invention is the first aspect of the present invention.2In any of the above, the molded article is formed by heat-molding a thermoplastic synthetic resin sheet in a vacuum state or in a vacuum / compressed air state.
[0008]
  Claims of the invention4In claim 1, the side mold is formed into four parts, and the side molds facing each other among the four divided side molds are provided so as to be able to advance and retreat with respect to the bottom mold. Adopted a means to do.
[0009]
  Claims of the invention5(F) By vacuum forming a thermoplastic synthetic resin sheet or by vacuum / pressure formingFormed in a generally dished or bottomed box shapeA substantially horizontal side wall formed by cutting a side wall provided substantially perpendicularly to the outside of the main body and an extending end disposed outward in a substantially horizontal direction with respect to the side wall at a position outside the side wall. With the leg seatIn the plastic container provided,
(G) A substantially annular upper edge portion is formed in a desired width on the outer periphery of the upper surface of the body portion
(H) A substantially horizontal locking step portion is continuously provided around the upper edge portion,
(L) The side wall is provided substantially vertically so as to surround the main body part below the locking step part,
(N) The leg seat is formed by cutting the extending end to a position outside the side wall through a recess recessed in a substantially horizontal direction inside the lower side with respect to the side wall,
(L) The leg seats of the containers to be stacked are provided so as to be stacked in a desired number of stages by being fitted to the locking steps provided on the outer periphery of the upper surface of the container disposed below.
(E)With featuresAdopted a means to do.
[0011]
  Claims of the invention6Claims5In the above-mentioned method, the side wall is formed by arranging a concave surface portion and a convex surface portion alternately in the lateral direction partially or entirely.
[0012]
  Claims of the invention7Claims5Or6In the method, the side wall is formed in such a manner that concave portions and convex portions are alternately arranged in the longitudinal direction partially or entirely.
[0013]
  Claims of the invention8Claims57Any one itemIn this case, the leg seat portion is cut at a position outside the side wall by 0.5 to 30 mm.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific examples of embodiments of the present invention will be described with reference to the drawings.
1 to 11 show an embodiment in which the present invention is applied to a vacuum forming apparatus for forming a plastic container for transporting electronic parts and mechanical precision parts between production assembly lines and offices.
The vacuum forming apparatus 1 in this embodiment includes a bottom mold 3A provided with a number of vacuum suction holes 2a, 2b, 2c; 2a, 2b, 2c, and the bottom mold 3A around the bottom mold 3A. By disposing outwardly in the substantially horizontal directions X and Y through a projecting portion 4 provided so as to be able to advance and retract in substantially horizontal directions X and Y and projecting inward from the substantially vertical side wall 6d of the molded product S described later. A plurality of side molds 5A forming extended ends 6f for cutting at desired positions₁, 5A₂; 5B₁, 5B₂And a divided mold formed of
[0015]
Multiple side molds 5A₁, 5A₂; 5B₁, 5B₂The bottom mold 3A surrounded by is fixed to the upper surface of the base plate B as shown in FIG. And this bottom part formwork 3A is the convex part 3A for forming the main-body part 6a of the molded article S.₁And the convex part 3A₁Is formed with a desired width t on the top surface of the molded product S to form the upper edge portion 6b of the molded product S, and the side mold 5A is formed around the recess portion 7.₁, 5A₂; 5B₁, 5B₂The extending end 6f formed on the molded product S by the projecting portion 4 projecting inwardly is cut at a desired position with a cutting angle of approximately 90 ° to form a substantially horizontal formed below the periphery of the molded product S. A rising step portion 7a is formed continuously to form a locking step portion 6c to which the leg seat portion 6g is detachably locked.
In this embodiment, the bottom mold 3A is raised or lowered with respect to the synthetic resin sheet 9 or the molded product S described later at the time of molding or releasing.
[0016]
Said side part formwork 5A₁, 5A₂; 5B₁, 5B₂In this embodiment, as shown in FIG. 3, it is formed into four parts in the front / rear and left / right directions.₁, 5A₂; 5B₁, 5B₂Of the opposite side molds 5A₁, 5A₂Side formwork 5B facing₁, 5B₂They are slid relative to the bottom mold 3 </ b> A so as to be able to advance and retract in the substantially horizontal directions X and Y, for example, by the driving force of the cylinder 8.
These side molds 5A₁, 5A₂; 5B₁, 5B₂In this embodiment, during the molding as shown in FIGS. 1 to 3 and during the mold release as shown in FIGS. 4 and 5, the cylinder 8 is driven by the driving force of the cylinder 8 at the same time. Even if not, it may be driven so as to be able to advance and retreat with a time difference.
[0017]
The plastic container 6 as the molded product S is formed in a substantially bottomed box shape upside down as shown in FIG. 2 and FIG. As shown in FIG. 2, molding is performed by evacuating the inside of the lower chamber. In this molding, the molded product S is molded by heating and inserting a semi-molten thermoplastic synthetic resin sheet 9 into the vacuum molding apparatus 1. Further, as the thermoplastic synthetic resin sheet 9, for example, a modified polyphenylene ether resin alloyed with polystyrene is optimally used from the advantage that heat-resistant, small thermal shrinkage and high-precision molded products can be obtained. However, the present invention is not limited to this, and other thermoplastic synthetic resins such as PET resin, ABS resin, polystyrene resin, polypropylene resin, and polyvinyl chloride resin may be used for molding.
[0018]
Further, as described above, the plastic container 6 is formed into a substantially bottomed box shape as described above. For example, as shown in FIGS. 6 to 8, the main body portion 6a having a substantially dish shape, and the main body portion 6a An upper edge portion 6b formed on the upper surface with a desired width t 'having a substantially annular shape, a locking step portion 6c connected to the outer periphery of the upper edge portion 6b substantially horizontally with a step, and the locking step A side wall 6d provided substantially perpendicular to the outer position so as to surround the main body portion 6a below the portion 6c, and a recess 6e recessed substantially in the horizontal directions X and Y inside the lower portion of the side wall 6d. It comprises a substantially horizontal leg seat portion 6g formed by cutting an extending end 6f disposed outward in the horizontal directions X and Y at a position outside the side wall 6d. The leg seat 6g needs to be cut at a desired position outside the side wall 6d. Preferably, the leg seat 6g is within a range of 0.5 to 30 mm from the side wall 6d as shown in FIG. Cutting at the outer position can be optimally performed without tilting or causing burrs without tilting the molded product with respect to the cutter in the cutting device having the same structure as the conventional cutting device as shown in FIG.
In the illustrated embodiment, the main body 6a is formed in a substantially dish shape as described above, but its depth H is arbitrarily set. Further, in the illustrated embodiment, the main body 6a is formed in a raised bottom shape and is surrounded by a substantially vertical side wall 6d, so that electronic parts and mechanical precision parts housed in the main body 6a are protected from the influence of the ambient temperature. can do. Moreover, since the recess 6e is formed inwardly between the substantially vertical side wall 6d and the leg seat portion 6g below the side wall 6d, the recess 6e is bent to exhibit cushioning properties. Since it is not necessary to directly transmit the impact, it is possible to mitigate the impact when the plastic container 6 is lifted and lowered during transportation of electronic parts or the like as the contents housed in the main body 6a of the plastic container 6.
The plastic container 6 is stacked in a desired number of stages. For this, the leg seat 6g of the upper plastic container 6 is fitted in the locking step 6c provided on the outer periphery of the upper surface of the plastic container 6 disposed in the lower stage so as to be locked in a substantially horizontal direction. By positioning in the X, Y and vertical directions Z, the desired number of plastic containers 6 are stacked.
Further, the side wall 6d has a concave portion 6d on the entire surface as shown in another modification of the plastic container 6 of FIG. 6, FIG. 7 or FIG.₁And convex part 6d₂Are alternately arranged in the horizontal direction to exhibit the rigidity of the side wall 6d.
[0019]
An embodiment of the vacuum forming apparatus 1 for the plastic container 6 according to the present invention has the above-described configuration. Hereinafter, a case where the plastic container 6 is formed using the vacuum forming apparatus 1 will be described in the order of steps.
In molding the plastic container 6, as shown in FIG. 1, a bottom mold 3A fixed on the base plate B of the vacuum forming apparatus 1 and a side mold 5A as a divided mold disposed around the bottom mold 3A.₁, 5A₂; 5B₁, 5B₂And have been lowered.
[0020]
After the thermoplastic synthetic resin sheet 9 is heated and plasticized to a processing temperature by a heating means such as an infrared heater (not shown), the bottom mold 3A and the side mold 5A are used.₁, 5A₂; 5B₁, 5B₂It is arranged on the upper surface.
[0021]
When the synthetic resin sheet 9 is disposed at a predetermined position with respect to the mold, the bottom mold 3A provided on the base plate B and the side mold 5A as a divided mold provided around the base mold B are provided.₁, 5A₂; 5B₁, 5B₂As soon as it is raised and touches the synthetic resin sheet 9, a vacuum pump (not shown) is actuated, and the desired number of vacuum suction holes 2a, 2b, 2c; 2a, 2b, 2c are provided in the bottom mold 3A. One side on the lower side of the sheet 9 is sucked to be in a vacuum state.
[0022]
Therefore, the synthetic resin sheet 9 which is softened and is vacuumed and sucked on the lower side is divided into a bottom mold 3A and a side mold 5A₁, 5A₂; 5B₁, 5B₂The molding is performed in conformity with the shapes provided on the upper surface and the inner surface.
In the illustrated embodiment, the plastic container 6 as a molded product is formed into a substantially bottomed box shape that is upside down.
[0023]
And the convex part 3A is formed on the upper surface of the bottom mold 3A of the vacuum forming apparatus 1.₁Since this is formed, this convex portion 3A₁As a result, a substantially dish-shaped main body 6a is formed. The convex part 3A₁Since a concave portion 7 having a substantially annular shape is formed in a desired width t around the upper portion 6, an upper edge 6 b as a molded product is formed in a desired width t ′ by the concave portion 7, and at the periphery thereof. A locking step 6c is formed. Also, the side mold 5A provided around the bottom mold 3A.₁, 5A₂; 5B₁, 5B₂Since the protruding portion 4 protrudes inwardly, the molded product S formed from the synthetic resin sheet 9 is substantially horizontal by the protruding portion 4 below the substantially vertical side wall 6d (upper portion in FIG. 2). Concave portions 6e are formed in the directions X and Y. Therefore, an extending end 6f is disposed outside the side wall 6d substantially perpendicular to the horizontal directions X and Y via the recess 6e.
The substantially vertical side wall 6d has a concave surface 6d on the entire surface.₁And convex part 6d₂Are alternately formed in the lateral direction.
[0024]
When predetermined molding is performed in this manner, vacuum suction from the lower surface of the synthetic resin sheet 9 is stopped.
Then the surrounding side formwork 5A₁, 5A₂; 5B₁, 5B₂Are retracted in the substantially horizontal directions X and Y, respectively, and the base plate B on which the bottom mold 3A is placed descends. Then, the synthetic resin sheet 9 on which the molded product S has been molded is released. At this time, air can be blown onto the outer or lower surface of the synthetic resin sheet 9 from the vacuum suction holes 2a, 2b, 2c;
[0025]
The molded product S which has been released from the mold is moved to a cutting means (not shown in the drawing) having the same structure as that shown in FIG. Thus, the plastic container 6 as a molded product is completed.
This cutting is substantially outside the side wall 6d via a recess 6e recessed inwardly in the substantially horizontal directions X and Y with respect to the substantially vertical side wall 6d of the plastic container 6 as a molded product. Since the horizontal extension end 6f is formed, if it is cut by the cutter of the cutting means outside the side wall 6d, for example, at an outside position in the range l of 0.5 to 30 mm as shown in FIG. The leading end 6f is cut without tilting. For this reason, the leg seat part 6g is formed on the cut end face of a beautiful finish with no cutting burr at a cutting angle of about 90 °. Since the leg seat portion 6g is formed in the substantially horizontal directions X and Y, the plastic container 6 can be stably placed on the floor surface T without rattling. Moreover, since the installation position of the plastic container 6 is constant, it is suitable for performing an operation using an automatic transfer device such as a robot in a production line or an assembly line.
[0026]
Further, the plastic container 6 has a substantially dish-shaped main body 6a, and a planar substantially annular upper edge 6b formed at a desired width t 'on the upper surface around the main body 6a. In order to protect the main body 6a with a strong structure and to protect the main body 6a, the main body 6a can accommodate a large amount of electronic parts, printed boards, etc. In the case of 6a, the main body 6a is prevented from being deformed by flexibility. In addition, a concave surface portion 6d is formed on the entire side wall 6d so as to surround the main body portion 6a via a locking step portion 6c provided around the upper edge portion 6b.₁And convex part 6d₂Are alternately arranged in the horizontal direction, the surrounding side wall 6d itself also exhibits rigidity in the vertical and horizontal directions and in the vertical direction, so that the bending is prevented and the structure can be made robust.
As described above, the plastic container 6 of the present embodiment is formed to have a strong structure and has improved durability. Therefore, the plastic container 6 can be reused by collecting it after use and washing dirt and dust.
[0027]
Further, as described above, the locking step portion 6c is formed around the upper edge portion 6b of the plastic container 6, and the legs extending in the substantially horizontal directions X and Y through the recess portion 6e at the lower portion of the vertical side wall 6d. Since the seat portion 6g is formed, the horizontal leg seat portion 6g of the upper plastic container 6 is fitted into the engaging step portion 6c of the lower plastic container 6 so as to extend in the substantially horizontal directions X and Y and the vertical direction Z. By performing positioning quickly and reliably, the plastic container 6 is stacked in a desired number of stages. At this time, the leg seat portion 6g extends to the outside substantially horizontally through a recess 6e that is recessed inward in the substantially horizontal directions X and Y with respect to the substantially vertical wall surface 6d. Since it is formed by cutting at a cutting angle of approximately 90 ° without tilting the cutter of the cutting means, it is formed horizontally with a sufficient width, so that stable stacking without wobbling or shaking occurs Can be done. Accordingly, it is possible to store and manage electronic parts and mechanical precision parts in a small area without taking up many installation places during storage.
[0028]
Further, the recess 6e exhibits cushioning properties when the plastic container 6 is lifted and lowered, and an impact is not directly transmitted to the main body 6a, so that the electronic component as the contents accommodated in the main body 6a of the plastic container 6 is used. The impact of lifting and lowering during transportation can be mitigated.
In addition, in the illustrated embodiment, the main body 6 is formed in a raised bottom shape and the periphery is surrounded by a substantially vertical side wall 6d, so that electronic parts and mechanical precision parts accommodated in the main body 6a are protected from the influence of the ambient temperature. can do.
[0029]
FIG. 12 and FIG. 13 show a second embodiment of the molding apparatus of the present invention. In this embodiment, the bottom mold 3A and the surrounding side mold 5A are shown.₁, 5A₂; 5B₁, 5B₂The upper mold 3B for pressure air is provided on the upper surface so as to be able to rise or descend, so that the bottom mold 3A and the upper mold frame for pressure air are formed when the plastic container 6 as the molded product S is molded or released. 3B is raised or lowered in the opposite direction. At the time of molding the molded product S, the synthetic resin sheet 9 becomes the bottom mold 3A and the side mold 5A.₁, 5A₂; 5B₁, 5B₂And the upper mold 3B, the bottom mold 3A and the side mold 5A on one side (lower chamber in FIG. 12) with the molded product S in the mold as a boundary.₁, 5A₂; 5B₁, 5B₂Since the inside is sucked into a vacuum state, and the synthetic resin sheet 9 is pressurized from above by being compressed into a compressed air state by sending compressed air into the inside of the upper mold 3B on the other side (upper chamber in FIG. 12). Unlike the above-described embodiment in which the lower chamber is vacuum-sucked to form the molded product S, the molded product S can be efficiently vacuum-compressed. In the illustrated embodiment, the bottom mold 3 </ b> A and the side mold 5 </ b> A as a divided mold are provided below the synthetic resin sheet 9.₁, 5A₂; 5B₁, 5B₂The upper mold 3B is disposed above, but the molded product S can be molded by using the lower mold for pressure air, and vacuuming the upper mold, contrary to the illustration. In other respects, the configuration and operation are the same as those of the previous embodiment.
[0030]
In each of the above embodiments, the case where the molded product S is molded upside down has been described as a typical example. However, the present invention is not limited to this, and the molded product S may be molded upright. Scope of application.
In each of the above embodiments, the side mold 5A is used.₁, 5A₂; 5B₁, 5B₂Is typically divided into four parts in the front, rear, left, and right directions, but the present invention is not limited to this, and the side mold may be divided into two or more parts, as shown in the figure. The flat rectangular shape is not limited to a flat rectangular shape.
[0031]
In addition, the plastic container 6 molded by the molding apparatus of each of the above embodiments forms a transport container used to transport electronic parts and mechanical precision parts between processes on the production assembly line or to transport them between offices. However, the application of the plastic container 6 is not limited to this, and the present invention is also applicable to the case of molding plastic containers such as packaging containers and packing containers for various parts.
[0032]
In the plastic containers of the above embodiments, the substantially vertical side wall 6d has a concave surface 6d on the entire surface.₁And convex part 6d₂However, the present invention is not limited to this, and the concave portion 6d is formed on a part of the side wall 6d.₁And convex part 6d₂The rigidity can also be exhibited when forming the. Further, the convex portion 6d₂And concave part 6d₁As shown in the drawing, the present invention is not limited to the case where it is formed in the lateral direction of the side wall 6d, and it is also within the scope of the present invention to exhibit rigidity when it is formed on the entire surface or part of the vertical direction.
[0033]
【The invention's effect】
  As described above, according to claim 1 of the present invention.IfA bottom mold with a vacuum suction hole, and a protrusion that protrudes inwardly from a substantially vertical side wall of the molded product provided around the bottom mold so as to be able to advance and retreat in a substantially horizontal direction with respect to the bottom mold Thermoplastic moldings are thermoformed in a split mold that comprises a plurality of side molds that are arranged on the outside in a substantially horizontal direction to form an extended end that cuts at a desired position.RupuPlastic container thermoforming equipmentInOn the upper surface of the bottom mold frame surrounded by the plurality of side molds, a planar substantially annular recess that forms the upper edge of the molded product is formed in a desired width.,Around the recess, the protrusion provided in the side moldThe extending end is formed;Lower the periphery of the molded product by cutting the extended end with a cutting angle of approximately 90 °.AbbreviationHorizontal leg seatIs formed on the leg seat,A locking step that is detachably locked is provided continuously.In addition, according to claim 5, the thermoplastic synthetic resin sheet is formed on the outside of the main body formed in a substantially dished or substantially bottomed box shape by vacuum forming or vacuum / pressure forming. A side wall provided substantially vertically, and a substantially horizontal leg seat portion formed by cutting an extended end disposed outward in a substantially horizontal direction with respect to the side wall at a position outside the side wall. An upper edge portion of a substantially annular plane is formed in a desired width on the outer periphery of the upper surface of the main body portion, and a substantially horizontal locking step portion is continuously provided around the upper edge portion, below the locking step portion. The side wall is provided substantially vertically so as to surround the main body portion, and the extension end is positioned outside the side wall through a recess recessed inwardly in a lower horizontal direction with respect to the side wall. The leg seat part is formed by cutting up and forming, and the leg seat part of the container to be stacked is disposed below. Provided to be desired number superimposed stacked by the engaging step portion lockably fitting in providing the upper surface outer periphery of the containerTherefore, when a plastic container molded by this thermoforming device is cut at the lower extension end by using a cutting device, the cutting angle of the extension end is cut to about 90 °, which causes rattling or instability. Nothing. Therefore, it is possible to use an automatic transfer device such as a robot, and the cutting end face is finished with a good appearance without causing burrs, so the yield is good, and the transport containers are stacked in a desired number of stages quickly and reliably during storage. As a result, the storage area can be reduced, the facility cost can be reduced, and the rigidity of the side wall of the plastic container can be demonstrated to make it structurally robust.
[0034]
Further, according to claim 2 or claim 3 of the present invention, a thermoplastic synthetic resin sheet is used, and the inside of the mold is vacuumed in the shape of a substantially bottomed box in the upside down direction, or the inside of one of the molded articles in the mold is the boundary. Since the other interior is heated and molded in a compressed air state, molding and mold release can be performed efficiently and reliably even in a complicatedly shaped plastic container having uneven surfaces everywhere.
[0035]
  Claims of the invention4The side mold is divided into four parts, and the opposing side mold is provided so as to be able to advance and retreat with respect to the bottom mold, so that the side mold is recessed in a substantially horizontal direction with respect to a side wall that is substantially vertical to the plastic container. A stable leg seat portion can be formed through the recessed portion.
[0036]
  Claims of the invention6Or claims7According to the above, the side wall of the plastic container is formed by arranging the concave and convex portions alternately in the horizontal direction or the vertical direction on a part or the whole surface, so that the rigidity of the side wall itself can be exhibited and the structure is robust. Can be molded.
[0037]
  Claims of the invention8According to the above, since the cutting portion of the leg seat portion of the plastic container is cut at an outer position in the range of 0.5 to 30 mm from the substantially vertical side wall, the waste piece is less waste and the cutting angle is about 90 °. Leg seats with a beautiful finish can be molded at low cost without producing burrs.
[Brief description of the drawings]
FIG. 1 shows a first embodiment of a vacuum forming apparatus as a thermoforming apparatus of the present invention, and is a cross-sectional view showing a state in which a synthetic resin sheet is disposed above a bottom mold frame and a side mold frame during molding.
FIG. 2 is a cross-sectional view showing a state in which a synthetic resin sheet is sucked by a vacuum forming apparatus during molding.
FIG. 3 is a cross-sectional view during molding in the same example.
FIG. 4 is a cross-sectional view showing the molded product in the same embodiment when released.
FIG. 5 is a transverse cross-sectional view at the same time of mold release.
FIG. 6 is an enlarged perspective view showing an example of a plastic container as a molded product molded by the vacuum molding apparatus of the present embodiment.
FIG. 7 is an enlarged plan view of the plastic container.
FIG. 8 is an enlarged cross-sectional view of a state where a plastic container is also installed on the floor surface.
FIG. 9 is an enlarged cross-sectional view showing a leg seat portion formed by cutting the extended end of the lower part of the plastic container.
FIG. 10 is a cross-sectional view showing a state in which plastic containers are similarly stacked.
FIG. 11 is an enlarged plan view showing another modification of the plastic container of the present invention.
FIG. 12 is a cross-sectional view of a molded product when another embodiment applied to a vacuum / pressure device as a thermoforming device of the present invention is shown.
FIG. 13 is a cross-sectional view of the molded product when released from the mold.
FIG. 14 is a cross-sectional view showing an example of this type of conventional molding apparatus.
FIG. 15 is a cross-sectional view showing the time of forming a transport container as a molded product.
FIG. 16 is a cross-sectional view showing a state where the outer periphery of the inclined side wall portion of the transport container is similarly cut using a cutting device.
FIG. 17 is an enlarged cross-sectional view partially showing the outer periphery of the inclined side wall portion of the transport container.
FIG. 18 is a cross-sectional view showing a state in which transport containers are similarly stacked.
FIG. 19 is a cross-sectional view showing an example of a conventional cutting apparatus for cutting a transport container from a remaining piece of synthetic resin.
[Explanation of symbols]
1 Vacuum forming equipment
2a Vacuum suction hole
2b Vacuum suction hole
2c Vacuum suction hole
3A Bottom formwork
3B Upper formwork
4 Protrusion
5A₁  Side formwork
5A₂  Side formwork
5B₁  Side formwork
5B₂  Side formwork
6 Plastic containers
6a Body
6b Upper edge
6c Locking step
6d side wall
6e recess
6f Extension end
6g Leg seat
9 Synthetic resin sheet
S molded product
T floor

Claims (8)

A bottom mold with a vacuum suction hole, and a protrusion that protrudes inwardly from a substantially vertical side wall of the molded product provided around the bottom mold so as to be able to advance and retreat in a substantially horizontal direction with respect to the bottom mold parts by pulp to heat molding a molded article of a thermoplastic plastic with split frame is disposed outward in a substantially horizontal direction comprising a plurality of side forms to form the extending end forming a cutting at a desired position In thermoforming equipment for plastic containers ,
(A) A planar, generally annular recess that forms the upper edge of the molded product is formed in a desired width on the upper surface of the bottom mold frame surrounded by the plurality of side mold frames ,
(B) the periphery of the recess portion and the extending end is formed by the projecting portion provided on the side forms,
(C) A substantially horizontal leg seat is formed below the periphery of the molded product by cutting the extended end with a cutting angle of approximately 90 ° .
(D) The leg seat, locking stepped portions to be engaged detachably engaged is continuously provided (e) thermoforming apparatus features and to pulp plastic container that.   The molded product is heated and molded in a vacuum with the inside of the mold in a vacuum with the bottom of the mold upside down, or one part is vacuumed and the other inside is compressed with the air inside the mold. The apparatus for thermoforming a plastic container according to claim 1. Moldings thermoforming apparatus of the plastic container according to claim 1 or 2 characterized in that it is formed by heat-molding a synthetic resin sheet of a thermoplastic in a vacuum state or a vacuum-pressure state.   The said side part formwork is formed in 4 divisions, The side part form frame which opposes among the 4 parts of this side part formwork is provided so that advancement / retraction is possible with respect to a bottom part formwork. The thermoforming apparatus of the plastic container as described. (F) Side walls provided substantially perpendicularly to the outside of the main body formed in a substantially dish-like or substantially bottomed box shape by vacuum forming or vacuum / pressure forming a thermoplastic synthetic resin sheet, and the side walls In a plastic container provided with a substantially horizontal leg seat formed by cutting an extended end disposed outward in a substantially horizontal direction at a position outside the side wall ,
(G) A substantially annular upper edge portion is formed in a desired width on the outer periphery of the upper surface of the body portion
(H) A substantially horizontal locking step portion is continuously provided around the upper edge portion,
(L) The side wall is provided substantially vertically so as to surround the main body part below the locking step part,
(N) The leg seat is formed by cutting the extending end to a position outside the side wall through a recess recessed in a substantially horizontal direction inside the lower side with respect to the side wall,
(L) The leg seats of the containers to be stacked are provided so as to be stacked in a desired number of stages by being fitted to the locking steps provided on the outer periphery of the upper surface of the container disposed below.
(E) A plastic container characterized by that. The plastic container according to claim 5 , wherein the side wall is formed by arranging a concave surface portion and a convex surface portion alternately in a lateral direction partially or entirely. Said side wall is a plastic container according to claim 5 or 6, characterized in that the concave portion and convex portion on a part or the entire surface is formed by vertically arranged alternately. Cutting point of the leg seat, the plastic container according to any one of claims 5-7, characterized in that it is cut by the outer position than 0.5~30mm from the side wall.

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