JP2002096407A - Method and device for forming cylindrical container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of defective products by surely adhering protruded part at an overlapping part protruding from a bottom plate toward a bottom edge. SOLUTION: When a sheet blank is to be cylindrically formed and adhered with a bottom plate which has a gluing part at its circumference, the sheet blank is nearly cylindrically wound on the bottom plate protruding its bottom edge from the bottom plate, and an overlapping part is nipped and adhered separately at both sides of the bottom plate by a first nipping means and a second nipping means. The first nipping means nips the both ends overlapping part of the sheet blank with a die and a pushing member. The second nipping means has a pair of pressing pawl which nips the overlapping part from the bottom edge of the sheet blank (at the bottom side of a cylindrical container) rather than form the bottom plate. As for the pressing pawls, one which swings like a scissors with center at a common pivot, or one which moves up and down in parallel may be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for forming a cylindrical container such as a cup by bending a sheet-like blank into a cylindrical shape and combining and bonding a bottom plate thereto. Things.

[0002]

2. Description of the Related Art An apparatus for automatically molding a cylindrical container such as a paper cup is known (for example, see Japanese Patent Application Laid-Open No. 7-195587). In this apparatus, for example, a substantially fan-shaped sheet-shaped blank is wound around a circular bottom plate and adhered to form a truncated cone-shaped cup.

[0003] Here, the bottom plate is formed into a marginal portion by drawing a peripheral edge, and a blank wound around this bottom plate in a cylindrical shape is folded back at its small diameter side to the inner diameter side and bonded so as to wrap the marginal portion of the bottom plate. Is done. The edge (opening edge) on the large diameter side (opening side) of the blank wound in a cylindrical shape is curled outward.

[0004] When the blank is wound in a tubular shape and both ends of the blank are overlapped and bonded, it is necessary to temporarily hold the both ends overlapping portion so as to prevent the bonded portion from peeling off. That is, a thermoplastic adhesive layer is formed on at least one surface of the blank in advance, and the adhesive layer is softened by heating with hot air or the like, and then the blank is wound and both ends are overlapped. And waits for the adhesive to harden.

FIG. 8 is a sectional view showing a holding means used in the step of bonding the overlapping portions. In FIG. 8, reference numeral 1 denotes a truncated conical mold (mandrel), and a bottom plate 2 can be sucked to the tip of the mold by negative air pressure or the like. The bottom plate 2 is formed by punching a roll paper into a circular shape and narrowing the peripheral edge thereof into a substantially flat plate shape. The bottom plate 2 is held by the mold 1 such that the margin 3 is located on the opposite side of the mold 1.

The blank 4 is formed by forming a thermoplastic adhesive layer on one side of a substantially fan-shaped cardboard. This adhesive layer is formed by laminating an adhesive film (thermocompression bonding) or applying an adhesive liquid. And dried. The blank 4 is placed under the mold 1 with the adhesive layer softened by heating up, and wound around the outer surface of the mold 1 by a pair of left and right winding levers.

At this time, both ends of the blank 1 are overlapped, and the overlapping portion 5 is pressed from above by a pressing member 6.
That is, the holding member 6 has substantially the same length as the generatrix of the mold 1, and sandwiches the overlapping portion 5 between the mold 1 and the holding member 6. Therefore, in this case, the holding means is formed by the pressing member 6 and the mold 1.

[0008]

Since the conventional holding means sandwiches the overlapping portion 5 between the mold 1 and the holding member 6, the holding member 6 can press the mold 1 only in a range where the mold 1 is below. Limited. That is, the protruding portion 7 on the lower edge side of the blank 4 with respect to the bottom plate 2 cannot be sandwiched. For this reason, there is a problem that the adhesion of the protruding portion 7 tends to be incomplete.

The protruding portion 7 is folded back to the inner diameter side in a later step, and is adhered so as to wrap the marginal portion 3 of the bottom plate 2 (bottom curl, bottom knurling). However, if the adhesion of the protruding portion 7 is incomplete, the adhesion will be peeled off in such a post-process, and a defective product will be generated.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and ensures that the protruding portion (7) of the overlapping portion (5) protruding from the bottom plate (2) to the lower edge side is securely bonded to the product. It is a first object of the present invention to provide a method for forming a cylindrical container that can prevent occurrence of defective products. It is a second object of the present invention to provide a cylindrical container forming apparatus directly used for carrying out this method.

[0011]

According to the present invention, a first object of the present invention is to provide a method for forming a cylindrical container, in which a sheet-like blank is formed into a substantially cylindrical shape and bonded with a bottom plate having a marginal portion formed on a peripheral edge thereof. A tube characterized in that the lower edge is protruded from the bottom plate, the blank is wound around the bottom plate in a substantially cylindrical shape, and the overlapping portions at both ends of the blank are separately clamped on both sides of the bottom plate to bond the overlapping portions. And a method for forming a container.

According to the present invention, a second object is to provide a cylindrical container forming apparatus for processing a sheet-like blank into a substantially cylindrical shape and bonding the sheet blank to a bottom plate having a marginal portion formed on a peripheral edge thereof.
A mold that holds the bottom plate at the tip and has an outer peripheral surface wound around the blank, a margin portion of the bottom plate and a winding portion that projects the lower edge of the blank from the mold and winds the blank, and both ends of the wound blank. A first and a second holding means for separately holding the overlapping portion on both sides of the bottom plate are provided, and a cylindrical container forming apparatus is provided.

The first holding means can be constructed in the same manner as the conventional apparatus described with reference to FIG. That is, the overlapping portion at both ends of the blank can be configured to be sandwiched between the mold and the pressing member. The second holding means may be configured to include a pair of crimping claws that sandwich the overlapping portion at both ends from the lower edge side of the blank (that is, the bottom side of the cylindrical container) from the bottom plate. The pair of crimping claws may be ones that swing like a scissor around a common fulcrum, or may be those that move up and down in parallel, and various driving methods can be adopted.

The blank is preferably provided with an adhesive layer on at least one surface, and the blank is wound into a cylinder with the adhesive layer inside. This is because the adhesive layer comes into contact with the marginal portion when the lower edge of the blank is folded back so as to surround the marginal portion of the bottom plate.

[0015]

FIG. 1 is a plan view of a cup forming apparatus, FIG. 2 is a view showing a former stage of the forming process, FIG. 3 is a view showing a latter stage of the forming process, FIG. Is a view showing a first holding means, FIG. 6 is a view showing a drive mechanism of a second holding means, and FIG. 7 is an operation explanatory view of the second holding means. First, the cup forming step will be described with reference to FIGS.

In FIG. 1, reference numeral 10 denotes a blank hopper, on which a sheet-like blank 12 shown in step S100 of FIG. 2 is stacked and loaded. The blank 12 is obtained by laminating (thermocompression bonding) a resin film of an adhesive on the surface of cardboard cut into a substantially fan shape, and can be formed into a conical cylindrical shape by rounding. Blank 1
No. 2 is laminated with the adhesive film laminated side up.

In FIG. 1, reference numeral 14 denotes a circular blank supply table which is rotatable intermittently about a vertical axis. Eight sets of blank positioning jigs 16 are mounted on the upper surface of the blank supply table 14 at equal intervals. Blank hopper 10
The blank 12 is placed on the positioning jig 16 (16A) facing the
Are supplied one by one, and this positioning jig 16 (16A)
The blank 12 is positioned.

The blank supply table 14 rotates counterclockwise as indicated by the arrow in FIG. 1, and the blank 12 is heated by the hot air sent from the heated air blower 18 (step S102 in FIG. 2). The blank supply table 14 further rotates to move the heated blank 12 to the position of the winding device 20 (Step S106 in FIG. 2).

In FIG. 1, reference numeral 22 denotes a cup forming table, which is rotatable about a vertical axis. This cup forming table 22 is octagonal in plan view, and eight frusto-conical (frusto-conical) molds (mandrels) 24 are radially mounted (see FIGS. 4 to 7). A spindle 26 penetrates these molds 24 so as to be able to advance and retreat in the radial direction, and a bottom plate holding portion 26A is attached to the tip of the spindle 26 (the tip on the outer diameter side of the cup forming table 22) (FIG. 6).

In FIG. 1, reference numeral 28 denotes a paper roll, and a roll paper 30 fed from the paper roll 28 has a bottom punch /
The sheet is punched into a circle by the drawing device 32, and the periphery thereof is drawn to form a bottom plate 34 (FIG. 2, step S1).
04). The bottom plate 34 is attracted to the bottom plate holding portion 26A of one of the spindles 26 of the cup forming table 22 by negative pressure. At this time, the drawn portion of the peripheral edge of the bottom plate 34 is a portion to be a margin portion 36, and the margin portion 36 is located on the side opposite to the mold 24.

The cup forming table 22 rotates clockwise in FIG. 1, and the bottom plate 34 attracted to the spindle 26 is heated by a heating unit 38.
, And transferred to the winding device 20. In this winding device 20, the heated blank 12 supplied from the blank supply base product 14 is
2, the blank 12 is extruded below the bottom plate 34 that has been transferred by the
Into a cylindrical shape (frustoconical shape) so as to conform to the outer shape of.

That is, winding levers 39, 39 shown in FIGS. 4 and 5 are disposed below the mold 24 so as to be rotatable about a common support shaft 39A. The winding levers 39, 39 have a substantially circular winding surface 39B along the outer periphery of the mold 24,
39B are formed. The two winding levers 39, 39 rotate upward from the fully open position shown in FIG. 4, and wind the blank 12 into a cylindrical shape with the blank 12 sandwiched between the winding surfaces 39B, 39B and the mold 24. At this time, the winding levers 39, 39 are rotated such that the lever 39 (a) on the left side in FIG. 5 precedes the lever 39 (b) on the right side. Both ends of the blank 12 are shown in FIG.
, And this is the overlapping portion 12A.

The overlapping portion 12A is provided on both sides of the bottom plate 34 with a first holding means 80 and a second holding means 82, respectively.
Sandwiched by to ensure adhesion. The first holding means 80 is similar to the holding means described with reference to FIG.
And a pressing member 84. Here, the pressing member 84 is along the generatrix of the mold 24 and has substantially the same length as this generatrix. The pressing member 84 can move up and down, and when it descends, it sandwiches the overlapping portion 12A between the mold 24 and the overlapping portion 12A.

The second holding means 82 is, as shown in FIG.
The overlapping portion 12A has a pair of pressure claws 88, 88 that sandwich a protruding portion 86 of the overlapping portion 12A from the bottom plate 34 to the bottom side. Crimping claws 88, 88
Are fixed to each other.
A lever 92 is fixed to one of the pressing claws 88, and the lever 92 is swung by an air cylinder 94. Therefore, when the air cylinder 94 expands and contracts, the lever 92 rotates, and the pair of press-fitting claws 88, 88 rotate synchronously in opposite directions via the gears 90, 90.

That is, when the air cylinder 94 is contracted and the lever 92 is pulled, the pressure claws 88, 88 open widely, and during this time, the winding device 20 winds the blank 12 into a cylindrical shape. After winding the blank 12 and stacking both ends, the air cylinder 94 extends, and the crimping claws 88, 88 project the protruding portion 8 of the overlapping portion 12 </ b> A.
6 is sandwiched.

As described above, the first and second holding means 8 are provided.
At 0, 82, the overlapped portion 12A is stopped for a while in a state where the overlapped portion 12A is held at a predetermined pressure, and waits for the overlapped portion 12A to be securely pressed (FIG. 2, step S106). Then, the pressing claws 88, 88 of the second holding means 82 are opened, and the cylindrical blank 12 is opened.
To prevent the blank 12 from coming into contact with the pressing claws 88 when the cup forming table 22 is rotated.

The pressing members 84 of the first holding means 80 are provided on the eight dies 24, respectively.
In a state where both ends of the blank 12 wound in a cylindrical shape are overlapped and pressed, a bottom forming step described later is started.

Next, the cup intermediate formed body 40 (FIG. 2) produced in this way rotates the cup forming table 22 to enter the next bottom forming step (FIG. 3, step S108). In the bottle molding step (S108), first, the intermediate molded body 40
Is transferred to the bottom heating unit 42 (FIG. 1), where the intermediate molded body 40 is heated from the bottom side with heated air, and the inner surface of the lower part (projection portion 86) of the blank 12 projecting below the bottom plate 34 is removed. Soften the adhesive (FIG. 3, step S108)
a).

Next, the intermediate molded body 40a is transferred to the bottom curl portion 44, where the lower edge of the blank 12 is turned inward to wrap the marginal portion 36 of the bottom plate 34 (step S).
108b). The bottom curl portion 44 includes a curling mold having an annular groove having a U-shaped cross section, and by rotating the mold while pressing the annular groove against the lower edge of the blank 12,
The lower edge of the blank 12 is folded back. Next, the intermediate molded body 40b is transferred to the bottom knurl processing section 46, where a roller with knurls is rolled in contact with the lower edge of the folded back blank 12 from the inside diameter side, and the lower edge of the blank 12 is attached to the margin portion 36 of the bottom plate 34. (FIG. 3, step S108c). Thereafter, the pressing member 82 forming the first holding means 80, which has been continuously pressing the both ends of the blank 12 by the winding device 20, is separated from the intermediate molded body 40c.

The intermediate molded body 40c that has been subjected to the bottom knurling process is transferred from the cup molding table 22 to the top molding table 50, where the top curl processing is performed (FIG. 3, step S110). The top forming table 50 is octagonal in a plan view, is rotatable around a vertical axis, and has eight work holding portions 52 on the outer periphery. The intermediate molded body 40c is transferred from the cup molding table 22 to one work holding table 52 of the top molding table 50. At this time, the intermediate molded body 4 that is
0c has its bottom side (bottom side) on the rotation center side and its opening edge (top) on the outer peripheral side.

The top molding table 50 rotates counterclockwise in FIG. 1, and a silicone paint is applied to the inner surface of the intermediate molded body 40c by the silicone application section 54 to improve the sealing property (FIG. 3, FIG.
Step S110a). The intermediate molded body 40d thus coated with silicon is sent to the top curling portions 56 and 58, where the opening edge (top) 60 is curled outward.

In this embodiment, two top curls 5
6 and 58, and top curl processing is performed in two stages,
The operation may be performed at once by one top curl portion 56 or 58. The top curls 56 and 58 include a curling mold that moves back and forth on the center axis of the intermediate molded body 40d and rotates. An annular groove having a U-shaped cross section is formed in the curl mold so that the opening edge (top) of the intermediate molded body 40d is engaged. The two top curls 56 and 58 differ only slightly in the shape of the annular groove, but if these two are used, the top curl can be performed in two stages. It is possible to clean the finish.

When the top curl die is pressed against the opening edge (top) of the intermediate molded body (work) 40d while rotating, the opening edge 60 is guided to the inner surface of the annular groove and curls outward. The cup that has been subjected to the top curl processing is transferred from the top curls 56 and 58 to the discharge unit 70 and discharged to the cup storage box 72.

In this embodiment, the second holding means 82
Although the protruding portion 86 is clamped except for the marginal portion 36 of the bottom plate 34, it may be clamped including the marginal portion 36. Although the crimping claws 88, 88 linearly sandwich the protruding portion 86, the protruding portion 86 is folded inward in a later process, so that the crimping surface of the crimping claw is curved or the crimping surface has a convex or concave portion. The shape may be added to facilitate the folding process (bottom curl).

The second holding means 82 may be a crimping claw that moves in parallel in a direction crossing the protruding portion 86, instead of the crimping claws 88, 88 that open and close like scissors. In this case, it is necessary that the pressing claws inside the protruding portion 86 can move forward and backward in the direction of the center axis of the mold 24 so as not to come into contact with the protruding portion 86 when the cup forming table 22 rotates.

It is preferable to control the temperature of the pressing claws 88, 88 in order to further securely press the overlapping portion 86. For example, it is also possible to cool the pressure-bonded portion with a pressure-bonded claw to accelerate the curing of the adhesive. Also, the adhesive may be heated once to soften the adhesive sufficiently (again) and then rapidly cooled to cure the adhesive. Thus, various temperature control methods are possible according to the type of the adhesive or the like.

In the embodiment described above, the pressing member 84 of the first holding means 80 is provided on each of the molds 24, and the second holding means 82 is arranged corresponding to the position of the winding device 20. As a result, the blank 12 is
The first and second holding means are configured to operate together at a position where the first holding means and the second holding means are wound around the outer periphery of the cylinder 4, but the first holding means and the second holding means are arranged along the periphery of the cup forming table 22. May be separately provided, and the holding step by the first holding means and the holding step by the second holding means may be performed separately.

[0038]

According to the first aspect of the present invention, as described above, the blank is wrapped around the bottom plate and the overlapping portions at both ends are separately clamped on both sides of the bottom plate, so that the reliability of the adhesion of the overlapping portion is improved. I do. For this reason, there is less possibility that defective products will be generated in the post-process.

According to the second to sixth aspects of the present invention, there is provided an apparatus directly used for performing the method.

[Brief description of the drawings]

FIG. 1 is a plan view of a cup forming apparatus.

FIG. 2 is a diagram showing a former stage of the molding process;

FIG. 3 is a view showing the latter stage of the molding process.

FIG. 4 shows a winding device.

FIG. 5 is a view showing a first holding means.

FIG. 6 shows a second holding means.

FIG. 7 is an explanatory view of the operation of the second holding means.

FIG. 8 is a sectional view showing a conventional holding means.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Blank 12A Overlapping part 14 Blank supply stand 22 Cup forming stand 24 Die (mandrel) 34 Bottom plate 36 Overlapping part 39 Winding lever 50 Top forming stand 80 First clamping means 82 Second clamping means 84 Pressing member 86 Projecting part 88 Crimp claw

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E075 BA33 CA01 DD03 DD32 DD34 DD45 DD49 GA04

Claims (5)

[Claims] 1. A method for forming a cylindrical container, wherein a sheet-shaped blank is processed into a substantially cylindrical shape, and is bonded to a bottom plate having a margin portion formed on a peripheral edge thereof, wherein the lower edge of the blank is projected from the bottom plate to form the blank. Is wound around the bottom plate in a substantially cylindrical shape, and the overlapping portions at both ends of the blank are separately sandwiched on both sides of the bottom plate to bond the overlapping portions. 2. A cylindrical container forming apparatus for processing a sheet-like blank into a substantially cylindrical shape, and bonding the sheet blank to a bottom plate having a marginal portion formed on a peripheral edge thereof. And a winding portion for projecting a margin of the bottom plate and a lower edge of the blank from the mold to wind the blank, and a first end for separately holding both ends of the wound blank on both sides of the bottom plate. And a second holding means. 3. The cylindrical container molding apparatus according to claim 2, wherein the first holding means is formed by a pressing member for holding the overlapping portion at both ends between the mold and the mold. 4. The cylindrical container forming apparatus according to claim 2, wherein the second holding means includes a pair of pressure claws for holding the overlapping portion at both ends from the lower edge of the blank from the bottom plate. 5. The blank has a thermoplastic adhesive layer formed on at least one surface thereof, and the winding portion winds the blank in a tubular shape with the adhesive layer inside.
Any one of the cylindrical container molding apparatuses.