Paper lid production method

Abstract

[Problem] To increase overall molding speed when producing a dome-shaped paper lid. [Solution] The present invention comprises: a blanking step for pushing a center region of a blank 10 constituted mainly by paper in a first direction while restraining peripheral edges of the blank 10, thereby forming a top plate part 11 and an enclosed part 12 which is provided along the outer periphery of the top plate part 11 and which extends in a second direction; and a pressing step for, after moving the blank 10 to a press part 52 and after restraining the center region while restraining the peripheral edges of the blank 10 that has been moved to the press part 52, sandwiching a region which is separate from and outward of the outer periphery of the enclosed part 12 with a plunger 140 that is formed so as to be recessed in the first direction and a draw punch 130 that is formed to protrude in the first direction, thereby forming an outer extending part 13 that is provided along the outer periphery of the enclosed part 12 and that extends outward, an inner fitting part 14 that is provided along the outer periphery of the outer extending part 13 and that extends in the first direction, and a top part 15 that is provided along the outer periphery of the inner fitting part 14 and that extends outward.

Description

Method for manufacturing a paper lid

[0001] The present invention relates to a method for manufacturing a paper lid.

[0002] As lids for paper containers such as paper cups, resin lids made of plastic or the like are used. However, when disposing of resin lids, it is necessary to separate them from paper cups and paper containers, which is troublesome for consumers. In particular, as a measure against global warming, reduction of resin usage and reduction of CO ２ are required, and the switch from resin lids to paper lids is increasing.

[0003] Paper lids can generally be roughly classified into two types: a flat lid shape with a flat top plate and one with a top plate bulging upward. Among them, for types that drink using a straw, such as cold beverages, a flat lid shape is applied, but for types that drink directly from the container to the mouth, such as hot beverages, or types with toppings such as cream, a so-called dome shape with a top plate bulging upward is often applied.

[0004] Such a paper lid having a dome shape was generally manufactured by a press machine as shown in, for example, Patent Document 1. By this press machine, with the periphery of the blank held, the draw die, blank holder, draw punch, plunger, etc. are pushed upward or downward to form the top plate portion and the wrapped portion corresponding to the dome-shaped portion, and further, the inner fitting portion and the outer fitting portion for fitting with the paper container.

[0005] Japanese Patent Application Laid-Open No. 2024-107715

[0006] However, according to the disclosed technique of Patent Document 1, it was premised that the entire molding process from one blank to one paper lid having a dome shape was completed by one press machine. Therefore, until the molding of one paper lid was completed, the next blank could not be loaded into that press machine, and since a waiting time was required for that amount, there was a problem that the molding speed could not be improved. Also, when molding by sharing each process with a plurality of press machines, since it takes time to convey the blank during molding between the press machines, there was also a problem that the overall molding speed could not be improved.

[0007] Therefore, the present invention was devised in view of the above-mentioned problems, and its objective is to provide a method for manufacturing a paper lid that can improve the overall molding speed when manufacturing a dome-shaped paper lid.

[0008] To solve the above-mentioned problems, the present invention is characterized by comprising: a blanking step in which a blank mainly made of paper is pressed in a first direction by a first pressing part while the periphery of the blank is pressed down, thereby forming a top plate portion and a covered portion provided along the outer circumference of the top plate portion and extending in the second direction; a first moving step in which the first pressing part is separated from the blank in a second direction opposite to the first direction, and then the blank is moved to a press section; and a pressing step in which the periphery of the blank moved to the press section is pressed with a paper pressing member while the central region is pressed down by a second pressing part, and then the region separated outward from the outer circumference of the covered portion is clamped by a plunger formed in a concave shape toward the first direction and a draw punch formed in a convex shape toward the first direction, thereby forming an outward extension portion provided along the outer circumference of the covered portion and extending outward, an inner fitting portion provided along the outer circumference of the outward extension portion and extending in the first direction, and a top portion provided along the outer circumference of the inner fitting portion and extending outward.

[0009] According to the present invention, which has the configuration described above, in manufacturing a paper lid, each manufacturing process from upstream to downstream is divided and assigned from the blanking section to the underrib forming section, and the paper lid is finished in its final form by gradually molding at each manufacturing process while rotating the turret. As a result, after molding is completed in each manufacturing process, the turret is rotated to move the blank to the next process, and the next blank can be loaded sequentially and molded in that manufacturing process. In other words, blanks can be loaded sequentially into the manufacturing equipment without waiting for the molding of one paper lid to be completed, and multiple blanks can be manufactured simultaneously and sequentially from the blanking section to the underrib forming section. Therefore, compared to the conventional technology in which all molding processes are performed by one press machine and the next blank cannot be loaded into the press machine until the molding of one paper lid is completed, it is possible to improve the overall molding speed.

[0010] Figure 1(a) is a schematic plan view showing an example of a paper cover according to one embodiment of the present invention, and Figure 1(b) is a schematic cross-sectional view along the line IB-IB in Figure 1(a). Figure 2 is a schematic cross-sectional view showing an enlarged view of the area within the dashed frame II in Figure 1(a). Figure 3 is a diagram showing another form of a paper cover manufactured by a manufacturing method to which the present invention is applied. Figure 4 is a plan view showing an example of a manufacturing apparatus that can be used to manufacture a paper cover. Figure 5 is a schematic cross-sectional view of a manufacturing apparatus that can be used to manufacture a paper cover, taking the blanking section as an example. Figure 6 is a diagram for explaining the preceding manufacturing process in the blanking section. Figure 7(a) is a diagram for explaining the subsequent manufacturing process in the blanking section, and Figure 7(b) is a diagram showing the blank after it has been moved to the press section. Figure 8 is a diagram for explaining the preceding manufacturing process in the press section. Figure 9 is a diagram for explaining the subsequent manufacturing process in the press section. Figure 10 is a diagram for explaining the manufacturing process in the folding and forming section. Figure 11 is a diagram for explaining the manufacturing process in the heater section. Figure 12 is a diagram illustrating the manufacturing process in the spout processing section. Figure 13 is a diagram illustrating the manufacturing process in the roll-out section. Figure 14 is a diagram illustrating the preceding manufacturing process in the underrib forming section. Figure 15 is a diagram illustrating the subsequent manufacturing process in the underrib forming section. Figure 16 is an enlarged view of section C of Figure 15(a) showing the underrib forming section. Figure 17 is a diagram illustrating an example of each component in the underrib forming section. Figure 18 is a diagram illustrating the manufacturing process in the discharge section.

[0011] Hereinafter, embodiments of a method for manufacturing a paper lid to which the present invention is applied will be described in detail with reference to the drawings.

[0012] (Paper Lid) First, the structure of the paper lid manufactured by the manufacturing method to which the present invention is applied will be described. Figure 1(a) is a schematic plan view showing an example of a paper lid 1 manufactured by the manufacturing method to which the present invention is applied, and Figure 1(b) is a schematic cross-sectional view along the line IB-IB in Figure 1(a). Figure 2 is a schematic cross-sectional view showing an enlarged view of the area within the dashed frame II in Figure 1(a).

[0013] As shown in Figures 1(a), 1(b), and 2, the paper lid 1 consists of a blank 10 mainly made of paper and includes a top plate portion 11, a covering portion 12, an outward extension portion 13, an inner fitting portion 14, a top portion 15, an outer fitting portion 16, an under rib 17, an enlarged diameter portion 18, and a downward extension portion 19. The shape of the paper lid 1 when viewed from above is, for example, circular. Hereinafter, in Figures 1 and 2, the outside (direction X1) refers to the outward direction with respect to the paper container 2, which is to be fitted, for example, a paper cup; the bottom (direction X2) refers to the downward direction when the paper container 2 is placed on the bottom surface; the top (direction X3) refers to the upward direction when the paper container 2 is placed on the bottom surface; and the inside (direction X4) refers to the inward direction with respect to the paper container 2. However, these lower (direction X2) and upper (direction X3) directions are not limited to perfectly vertically downward and vertically upward, but also include diagonally downward and diagonally upward directions that are deviated from vertically downward.

[0014] Furthermore, the top plate portion 11 and the encasing portion 12 are responsible for the function of the paper lid 1 as a lid, preventing the contents inside the paper container 2 from scattering or leaking, while the remaining peripheral portion OEP (outer extension portion 13, inner fitting portion 14, top portion 15, outer fitting portion 16, under rib 17, enlarged diameter portion 18, and downward extension portion 19) are responsible for fitting with the paper container 2.

[0015] The top plate portion 11 extends outward (direction X1). The top plate portion 11 has a top surface 11a and a container surface 11b. The container surface 11b is on the underside of the top surface 11a. When the paper lid 1 is fitted onto the paper container 2, the container surface 11b faces the container portion of the paper container 2. The top plate portion 11 may have recesses, protrusions, or other steps provided as appropriate from the viewpoint of convenience or decorative purposes.

[0016] A drinking spout 41 may be provided on the top plate portion 11 as appropriate. The drinking spout 41 has a hinge portion 41a and a peripheral edge portion 41b that bulges in direction X1 from one end to the other end of the hinge portion 41a. The hinge portion 41a may be made of a low-strength portion to facilitate bending. The peripheral edge portion 41b may be made of a cut that penetrates the top plate portion 11, or it may be made of a perforation or a low-strength portion.

[0017] The covering portion 12 is provided along the outer circumference of the top plate portion 11 and extends downward (in direction X2) from the top plate portion 11. This covering portion 12 is continuous with the top plate portion 11. In this case, the covering portion 12 may be molded so that its diameter gradually increases towards the bottom, in other words, so that it slopes outward when viewed in a side cross-section. The continuous portion between the covering portion 12 and the top plate portion 11 may also be molded in a rounded, streamlined shape. With a covering portion 12 having such a form, the top plate portion 11 can be closed at a position spaced apart from the paper container 2. Furthermore, with the top plate portion 11 and the covering portion 12, it is possible to mold it into a so-called dome shape that bulges upward, making it applicable to types where hot beverages are consumed directly from the container, or types where toppings such as cream are added.

[0018] The extension portion 13 is provided on the peripheral edge OEP of the paper lid 1, along the outer circumference of the encasing portion 12, and extends outward (direction X1). This extension portion 13 is continuous with the encasing portion 12. The extension width of this extension portion 13 is not particularly limited, but as will be described later, it may be sized so that the inner fitting portion 14 can contact the inner circumferential surface 21 of the container portion of the paper container 2 when the paper container 2 is fitted.

[0019] The inner fitting portion 14 is provided on the peripheral edge OEP of the paper cover 1, along the outer circumference of the outer extension portion 13, and extends upward (direction X3). This inner fitting portion 14 is continuous with the outer extension portion 13. The inner fitting portion 14 may have a substantially uniform diameter, in other words, it may rise up to the top portion 15 in a substantially vertical direction in a cross-sectional view, but is not limited to this, and may gradually increase in diameter outward towards the top portion 15.

[0020] The top portion 15 is provided on the peripheral edge OEP of the paper cover 1, along the outer circumference of the inner fitting portion 14, and extends outward (direction X1). This top portion 15 is continuous with the inner fitting portion 14. In its cross-section, the top portion 15 includes a curved surface that is convex upward (direction X3).

[0021] The outer fitting portion 16 is provided on the peripheral edge OEP of the paper lid 1, along the outer circumference of the top portion 15, and extends downward (direction X2). This outer fitting portion 16 is continuous with the top portion 15. The outer fitting portion 16 is separated from and opposite the inner fitting portion 14. Below the top portion 15, an annular recess 20 is provided between the inner fitting portion 14 and the outer fitting portion 16, with the inner fitting portion 14 and the outer fitting portion 16 serving as the surrounding walls and the top portion 15 as the base. The annular recess 20 is fitted into the paper container 2. At this time, the inner fitting portion 14 fits into the inner circumferential surface 21 of the container portion of the paper container 2, and the outer fitting portion 16 fits into the outer circumferential surface of the curl portion 28 of the paper container 2.

[0022] The underrib 17 is formed in continuous with the outer fitting portion 16 and is bent inward (direction X4). The underrib 17 includes a curved surface that is concave toward the inward (direction X4).

[0023] The enlarged diameter portion 18 is provided along the outer circumference of the under rib 17 and extends outward (direction X1) as it progresses downward (direction X2).

[0024] The downward extension portion 19 extends downward (in direction X2) from the lower end of the enlarged diameter portion 18.

[0025] The enlarged diameter portion 18 and the downward extension portion 19 may also be configured as a crimped portion 42 that is folded back and crimped from the end portion 10a of the paper lid 1. With such an enlarged diameter portion 18 and downward extension portion 19, it is possible to guide the paper container 2 into the annular recess 20 when fitting the annular recess 20 into the paper container 2.

[0026] In other words, in the cross-section of the paper lid 1, the encasing portion 12 bends downward (direction X2), the outer extension portion 13 bends outward (direction X1), the inner fitting portion 14 bends upward (direction X3), the top portion 15 bends outward (direction X1), the outer fitting portion 16 bends downward (direction X2), and the underrib 17 bends inward (direction X2), resulting in a curved surface that is concave inward (direction X4). Furthermore, the enlarged diameter portion 18 extends diagonally downward (directions X1 and X2), and the downward extension portion 19 extends downward (direction X2). That is, each of the top plate portion 11, the encasing portion 12, the outer extension portion 13, the inner fitting portion 14, the top portion 15, the outer fitting portion 16, the underrib 17, the enlarged diameter portion 18, and the downward extension portion 19 is obtained from a single blank 10.

[0027] In a paper lid 1 of this shape, the boundaries between the top plate portion 11 and the encased portion 12, the encased portion 12 and the extension portion 13, the extension portion 13 and the inner fitting portion 14, the inner fitting portion 14 and the top portion 15, the top portion 15 and the outer fitting portion 16, the outer fitting portion 16 and the underrib 17, the underrib 17 and the enlarged diameter portion 18, and the enlarged diameter portion 18 and the downward extension portion 19 may be defined, for example, as the inflection point or the vicinity of the inflection point that occurs when the blank 10 is drawn into shape.

[0028] Furthermore, the paper lid 1 manufactured by the manufacturing method to which the present invention is applied is not limited to the shape described above. For example, as shown in Figure 3, the paper lid 1 may have at least a top plate portion 11, a covering portion 12, an outer extension portion 13, an inner fitting portion 14, and a apex portion 15, and may have any other configuration. In other words, the dotted line portion shown in Figure 3 is not particularly limited and may reflect any configuration or shape, or the dotted line portion itself may be omitted.

[0029] Next, an example of a method for manufacturing the paper lid 1 to which the present invention is applied will be described.

[0030] (Method for manufacturing paper lid 1) <Example of processing machine> Figure 4 is a plan view showing an example of a manufacturing apparatus 100 that can be used to manufacture a paper lid according to one embodiment of this invention.

[0031] The manufacturing apparatus 100 includes a feeder 60 for supplying blanks 10, a turret 50 for processing the blanks 10 that are transported via the feeder 60 in the circumferential direction, and a discharge unit 58 for discharging the paper lids 1 that have been processed and manufactured in the turret 50.

[0032] The feeder 60 consists of a transport path that transports the blanks 10 stacked in the base paper stand 61 one by one toward the turret 50. On this feeder 60, processing such as applying lubricant or creasing the blanks 10 may be performed.

[0033] The turret 50 is equipped with a blanking section 51, a pressing section 52, a bending section 53, a heater section 54, a mouthpiece processing section 55, a rollout section 56, and an underrib forming section 57 in order from the upstream section where the blank 10 is supplied from the feeder 60 to the downstream section 58. The turret 50 is arranged so as to form a roughly circular arc from the blanking section 51 to the underrib forming section 57. The turret 50 is rotatable counterclockwise in the figure, and the blank 10 to be processed is rotatably moved from the blanking section 51 upstream to the underrib forming section 57 and further downstream to the discharge section 58. The rotational drive of the turret 50 can be achieved via a drive mechanism (not shown) consisting of, for example, a motor and gears that transmit power based on the motor.

[0034] In this turret 50, each manufacturing process from upstream to downstream is divided and assigned from the blanking section 51 to the underrib forming section 57, and the paper lid 1, which is in its final form, is finished by gradually molding it at each manufacturing process while the turret 50 is rotated. In this turret 50, after blanking the blank 10 in the blanking section 51, it is rotated and conveyed to the press section 52. Next, after press molding the blank 10 in the press section 52, it is rotated and conveyed to the bending section 53. Next, after bending the blank 10 in the bending section 53, it is rotated and conveyed to the heater section 54. Next, after heat treatment of the blank 10 in the heater section 54, it is rotated and conveyed to the spout processing section 55. Next, after processing the spout 41 of the blank 10 in the spout processing section 55 and further curling molding is performed, it is rotated and conveyed to the rollout section 56. Next, the blank 10 is subjected to the formation of a crimped portion 42 in the roll-out section 56, and then rotated and conveyed to the underrib forming section 57. Next, the underrib 17 is formed in the underrib forming section 57, and then rotated and conveyed to the discharge section 58.

[0035] The paper lid 1, which has been molded in the turret 50, is supplied to the discharge unit 58. The discharge unit 58 then discharges the supplied paper lid 1 to the outside.

[0036] Figure 5 is a schematic cross-sectional view of the manufacturing apparatus 100, with the blanking section 51 as an example.

[0037] The manufacturing apparatus 100 includes a mandrel 71 attached to the turret 50, a cylindrical cam 73 attached to the upper side (direction X3) of the mandrel 71, and a blank 10 positioned below (direction X2) the mandrel 71, which is on the upper side (direction X3). The manufacturing apparatus 100 further includes a drive unit 75 for applying driving force in direction X3 or direction X2. The manufacturing apparatus 100 is capable of applying driving force to the mandrel 71 in the vertical direction, i.e., in direction X3 or direction X2, through the cylindrical cam 73. The blank 10 can be held by suction through the mandrel 71, and this mandrel 71 allows the turret 50 to move counterclockwise. This allows the blank 10 to rotate counterclockwise from the blanking section 51 to the underrib forming section 57.

[0038] Next, we will explain in detail each manufacturing process from the blanking section 51 to the underrib forming section 57.

[0039] As shown in Figure 6(a), the blanking section 51 includes a bottom punch 110, a blank holder 120, a draw punch 130, a plunger 140, a lower stripper 150, and an upper stripper 160. In addition, in the manufacturing apparatus 100, a stripper plate 170 and a punch block 180 are provided outside the bottom punch 110 and the blank holder 120. Figure 6 shows the cross-sectional shape of this manufacturing apparatus 100, and this cross-sectional shape is formed in the circumferential direction.

[0040] In actually manufacturing this paper cover 1 using the manufacturing apparatus 100, first the periphery of the blank 10 is pressed down by the stripper plate 170 and the punch block 180, and then the inner circumference of the blank 10 is pressed down by the bottom punch 110 and the blank holder 120. As shown in Figure 6(a), the bottom punch 110 and the blank holder 120 are pushed up in the upward direction ZU relative to the stripper plate 170 and the punch block 180. This allows the blank 10 to be cut at the boundary between the bottom punch 110 and the blank holder 120 relative to the stripper plate 170 and the punch block 180, thereby obtaining a blank 10 of the desired diameter.

[0041] After the blank 10 has been cut to the desired diameter, as shown in Figure 6(a), the periphery of the cut blank 10 is held down from above and below by the bottom punch 110 and the blank holder 120, and the lower stripper 150 is pushed up in the upward direction ZU, bringing it close to or in contact with the central region of the blank 10. Also, the lower end of the plunger 140 is in close proximity to or in contact with the surface of the blank 10.

[0042] Next, as shown in Figure 6(b), while the periphery of the blank 10 is held down by the bottom punch 110 and the blank holder 120, the lower stripper 150 and the draw punch 130 are pushed upward in the ZU direction, thereby pushing the central region of the blank 10 upward in the ZU direction. As a result, the blank 10 stretches upward in the ZU direction, and the central region of the blank 10 is pushed in, resulting in the formation of the external shape corresponding to the top plate portion 11 and the encased portion 12.

[0043] At this time, the cross-sectional shape of the draw punch 130 may be such that an annular protrusion 132 is formed at its upper end, and further, a stepped portion 133 provided with a step is provided downward from the tip of the annular protrusion 132 on the outside of the annular protrusion 132. Thereby, the top plate portion 11 and the covering portion 12 can be molded so that the blank 10 has an external shape corresponding to the annular protrusion 132 and the stepped portion 133. In the region of the blank 10 corresponding exactly to the stepped portion 133, an outer extension portion 13, an inner fitting portion 14, and a top portion 15 can also be formed as described later.

[0044] As shown in FIG. 6(b), the lower stripper 150 and the draw punch 130 may be pre-molded so that the upper stripper 160 and the plunger 140 have a shape that can be fitted to them in a state where they are pushed upward in the upward direction ZU. Thereby, the blank 10 can be sandwiched between the lower stripper 150 and the draw punch 130 that can be fitted to each other, and the upper stripper 160 and the plunger 140, and extended in the upward direction ZU, and the external shape corresponding to the top plate portion 11 and the covering portion 12 can be formed more reliably and with high precision. However, in extending the blank 10 in the upward direction ZU, it is not essential to sandwich the blank 10 between the lower stripper 150 and the draw punch 130, and the upper stripper 160 and the plunger 140. It is sufficient to push the lower stripper 150 and the draw punch 130 upward in the upward direction ZU at least while holding the peripheral edge of the blank 10. Further, the lower stripper 150 and the draw punch 130 are not limited to being configured separately from each other, and may be configured by a pressing portion integrated with each other and pushed upward in the upward direction ZU.

[0045] Next, as shown in FIG. 7(a), after separating the lower stripper 150 and the draw punch 130 from the blank 10, the blank 10 is moved by rotating the turret 50 from the blanking portion 51 to the pressing portion 52.

[0046] As shown in FIG. 7(b), the press section 52 includes a bottom punch 110, a blank holder 120, a draw punch 130, a plunger 140, a lower stripper 150, an upper stripper 160, and a plunger 135. It should be noted that each component and member after the press section 52 is not completely the same as the components and members in the blanking section 51 described above, but the same kind of components and members will be described with the same reference numerals. The plunger 135 is provided above the draw punch 130. An elastic body 137 is interposed between the draw punch 130 and the plunger 135. As a result, the draw punch 130 and the plunger 135 are biased in a direction away from each other via the elastic body 137. The elastic body 137 may be any elastic member that can exert a repulsive force in the direction of being pressed, and may be composed of, for example, a spring or the like.

[0047] After moving the blank 10 to the press section 52, first hold down the periphery thereof with the bottom punch 110 and the blank holder 120. Next, as shown in FIG. 8(a), raise the lower stripper 150, the plunger 135, and the draw punch 130 together in the upward direction ZU. As a result, the lower stripper 150 contacts the central portion of the top plate portion 11 of the blank 10, and the plunger 135 contacts the peripheral portion of the top plate portion 11 and the wrapped portion 12 of the blank 10.

[0048] The draw punch 130 is provided with an extended convex portion 136 that extends in the upward direction ZU on the more peripheral side. The outer side surface of the extended convex portion 136 is in surface contact with the side surface of the bottom punch 110 or is in a state of facing each other and being close. The end portion of the extended convex portion 136 in the upward direction ZU is formed convex in the upward direction. The convex end portion of the extended convex portion 136 in the upward direction ZU may have a curved surface formed.

[0049] Furthermore, the plunger 140, which faces the draw punch 130 in the upward direction ZU, extends further towards the periphery in the downward direction ZD, and its end is provided with a recess 146 formed in a concave shape toward the upward direction ZU. This recess 146 may be a curved surface and is shaped to fit precisely with the extended protrusion 136.

[0050] In the state shown in Figure 8(a), the lower stripper 150 and plunger 135 rise in the upward direction ZU, and the plunger 140 and upper stripper 160 first grip the blank 10. At this stage, the draw punch 130 is in contact with, or close to, an area of ​​the blank 10 that is spaced outward from the outer circumference of the encased portion 12, via the end of the extended projection 136 in the upward direction ZU.

[0051] Next, as shown in Figure 8(b), the draw punch 130 is pushed further in the upward direction ZU. As a result, the region of the blank 10 that is separated outward from the outer circumference of the encased portion 12 is pushed in the upward direction ZU via the extended projection 136 of the draw punch 130. At this time, the extended projection 136 of the draw punch 130 and the recess 146 of the plunger 140 can grip the blank 10 that has been pushed in the upward direction ZU. This makes it possible to form the outer portion 13, the inner fitting portion 14, and the portion corresponding to the top portion 15 of the blank 10.

[0052] As shown in Figure 8(a), in the first stage, the lower stripper 150 and plunger 135 first move upward in the ZU direction to press down on the top plate portion 11 and the encased portion 12 of the blank 10. Next, in the second stage, the draw punch 130 is pushed further upward in the ZU direction, and the area separated outward from the outer circumference of the encased portion 12 of the blank 10 is pushed upward in the ZU direction via the extended protrusion 136, thereby forming the outer extension portion 13, the inner fitting portion 14, and the portion corresponding to the top portion 15. This prevents the blank 10 from being subjected to excessive load and tearing.

[0053] If the pressing of the top plate portion 11 and the encased portion 12 in the first stage, and the pressing of the outer portion 13, the inner fitting portion 14, and the top portion 15 in the second stage are performed simultaneously, the blank 10 will be pulled by the drawing process of the outer portion 13, the inner fitting portion 14, and the top portion 15, which have folds. If the lower stripper 150 and plunger 135 are pressed down on the top plate portion 11 and the encased portion 12 at the same time, the blank 10 will be subjected to further stress from the pressing, which may cause it to tear.

[0054] Therefore, in the first stage, the top plate portion 11 and the encased portion 12 are pressed down with the lower stripper 150 and plunger 135, and then the draw punch 130 is pushed further upward ZU to form the outer portion 13, the inner fitting portion 14, and the portion corresponding to the top portion 15, thereby preventing the blank 10 from being pulled excessively and preventing it from tearing.

[0055] In this invention, an elastic body 137 is interposed between the draw punch 130 and the plunger 135 to bias them in a direction that separates them from each other. As a result, in the first stage of pressing the top plate portion 11 and the packaged portion 12 as shown in Figure 8(a), the draw punch 130 is biased in the downward direction ZD by the elastic body 137, so that the force of the draw punch 130 pushing the blank 10 in the upward direction ZU is prevented. In the second stage, the draw punch 130 is raised in the upward direction ZU while resisting the biasing force of the elastic body 137 and brought closer to the plunger 140, so that the area separated outward from the outer circumference of the packaged portion 12 is clamped by the extended convex portion 136 and concave portion 146. In this second stage, the upward pushing of the draw punch 130 while resisting the biasing force of the elastic body 137 is performed based on the driving force of the drive unit 75.

[0056] Next, as shown in Figure 9(a), with the periphery of the blank 10 held down by the bottom punch 110 and the blank holder 120, the plunger 140, upper stripper 160, draw punch 130, plunger 135, and lower stripper 150, which are holding the blank 10, are driven upward in the upward direction ZU. As a result, the periphery of the blank 10, which was held down by the bottom punch 110 and the blank holder 120, is sandwiched between the side surface of the blank holder 120 and the outer side surface of the extended projection 136 of the draw punch 130. The extended projection 136 is designed so that its outer side surface is in surface contact with the side surface of the blank holder 120, or so that they are facing each other and close together. Therefore, by driving the plunger 140, upper stripper 160, draw punch 130, plunger 135, and lower stripper 150, which hold the blank 10, upward in the upward direction ZU, the blank 10 itself is pulled upward in the upward direction ZU, and as a result, its periphery is also sandwiched between the side of the blank holder 120 and the outer side of the extended projection 136 of the draw punch 130. Since the side of the blank holder 120 and the outer side of the extended projection 136 of the draw punch 130 are extended downward in the downward direction ZD (upward direction ZU), the periphery of the blank 10 sandwiched between them can also be extended downward in the downward direction ZD. As a result, a portion corresponding to the outer fitting portion 16 can be formed on the blank 10.

[0057] Next, as shown in Figure 9(b), the draw punch 130, plunger 135, and lower stripper 150 are separated from the blank 10 in the downward direction ZD. Then, the blank 10 is moved from the press section 52 to the bending section 53 by rotating the turret 50.

[0058] As shown in Figure 10(a), the bending and forming section 53 includes a blank holder 120, a plunger 140, and an upper stripper 160. The bending and forming section 53 further includes a curling tool 190. The curling tool 190 has a recess 191 that is concave in the downward direction ZD. This recess 191 may be formed in the shape of a round groove.

[0059] After moving the blank 10 to the bending forming section 53, the curling tool 190 is pushed up in the upward direction ZU. As a result, the recess 191 is designed to be located at the extended end 16a of the outer fitting section 16 of the blank 10 in the downward direction ZD at the moment of pushing up, so that the extended end 16a can be inserted into the recess 191.

[0060] The extended end 16a of the outer fitting portion 16 of the blank 10 can be bent inward by being deformed by being inserted into the round groove-shaped recess 191.

[0061] Next, as shown in Figure 10(b), the curling tool 190 is moved away from the blank 10 in the downward direction ZD. Then, the blank 10 is moved from the bending forming section 53 to the heater section 54 by rotating the turret 50.

[0062] As shown in Figure 11(a), the heater unit 54 includes a blank holder 120, a plunger 140, and an upper stripper 160. The heater unit 54 further includes a heater 195. The heater 195 has a heater nozzle 196 that blows out hot air transported from the pipeline.

[0063] After moving the blank 10 to the heater section 54, the heater 195 is pushed up in the upward direction ZU. Then, the outlet 196a of the heater nozzle 196 is positioned just inside the outer fitting portion 16 of the blank 10, and hot air is ejected. As a result, the outer fitting portion 16 can be heated by the hot air ejected outward from the outlet 196a of the heater nozzle 196, and the resin originally laminated on the outer fitting portion 16 can be melted. Note that the heater section 54 itself is not essential and may be omitted. Also, the heating step in the heater section 54 is not limited to being performed after bending the extended end 16a in the bending forming section 53, but may be placed before or after any other step. Furthermore, the heating step in the heater section 54 may be introduced multiple times instead of just once.

[0064] Next, as shown in Figure 11(b), the heater 195 is moved away from the blank 10 in the downward direction ZD. Then, the blank 10 is moved from the heater section 54 to the spout processing section 55 by rotating the turret 50.

[0065] As shown in Figure 12(a), the spout processing section 55 includes a blank holder 120, a plunger 140, and an upper stripper 160. The spout processing section 55 also includes a curling tool 200 and a spout processing tool 202 integrally provided with the curling tool 200.

[0066] The curling tool 200 has a round groove-shaped curling portion 201. The curling portion 201 is designed so that when pushing up, the curling portion 201 is located at the extended end 16a of the outer fitting portion 16 of the blank 10. The spout processing tool 202 is provided on the surface of the curling tool in the upward direction ZU, and has a spout processing portion 202a at its upward direction ZU end, which has a shape formed to match the shape of the spout 41.

[0067] After moving the blank 10 to the spout processing section 55, the curling tool 200 and the spout processing tool 202 are pushed upward in the upward direction ZU. As a result, the extended end 16a of the outer fitting section 16 of the blank 10 can be inserted into the curling section 201 just as it is being pushed upward. In this state, as shown in Figure 12(b), the curling tool 200 and the spout processing tool 202 are pushed further upward in the upward direction ZU. This deforms the extended end 16a of the outer fitting section 16 of the blank 10 that has been inserted into the curling section 201, and a curled section 16b with a roughly U-shaped cross-section can be formed. Simultaneously, or before or after this, the spout processing section 202a comes into contact with the top plate section 11 of the blank 10 and is pushed upward in the upward direction ZU, thereby forming the spout 41.

[0068] Next, the curling tool 200 and the spout processing tool 202 are moved away from the blank 10 in the downward direction ZD. Then, the blank 10 is moved from the spout processing section 55 to the rollout section 56 by rotating the turret 50.

[0069] As shown in Figure 13(a), the rollout section 56 includes a blank holder 120, a plunger 140, and an upper stripper 160. The rollout section 56 also includes a first inner tool 210 and a first outer tool 220.

[0070] The first inner tool 210 is provided spaced apart from the plunger 140 and the upper stripper 160 in the downward direction ZD. The first inner tool 210 has a projection 211 that protrudes in the upward direction ZU and a side surface 211a formed on the outward side of this projection 211.

[0071] The first outer tool 220 is provided on the downward ZD side relative to the blank holder 120. This first outer tool 220 has an inwardly protruding portion 221 and an inner surface 221a of this protruding portion 221.

[0072] Initially, the first inner tool 210 and the first outer tool 220 are positioned such that the side surface 211a and the inner surface 221a are spaced apart from each other.

[0073] After moving the blank 10 to the rollout section 56, the first inner tool 210 and the first outer tool 220 are pushed upward in the upward direction ZU. This inserts the curled portion 16b of the blank 10 between the spaced-apart sides 211a and the inner side 221a.

[0074] Next, as shown in Figure 13(b), the first inner tool 210 is rotated eccentrically outward. As a result, the curled portion 16b of the blank 10 can be sandwiched between the side surface 211a and the inner surface 221a of the eccentric first inner tool 210. Consequently, the curled portion 16b becomes a compressed portion 42, which has a flattened shape formed by pressing together two substantially U-shaped cross-sections. The formation of such a compressed portion 42 can be easily achieved by heating the outer fitting portion 16 in the heater portion 54 and melting the resin. Furthermore, instead of melting the resin, the outer fitting portion 16 may be pressed together using an adhesive that has been pre-applied to it. Alternatively, the compressed portion 42 may be formed by so-called pseudo-adhesion, where the compression is based on the force applied by the pressure between the side surface 211a and the inner surface 221a, without using adhesive or melted resin. In this pseudo-adhesion, adhesive may be used in part. In this simulated bonding method, adhesive may be used in smaller amounts than normally used, or it may not be used at all.

[0075] After forming such a crimped portion 42 on the blank 10, the first inner tool 210 and the first outer tool 220 are separated in the downward direction ZD. Next, the blank 10 is moved from the roll-out portion 56 to the under-rib forming portion 57 by rotating the turret 50.

[0076] As shown in Figure 14(a), the underrib forming section 57 includes a blank holder 120, a plunger 140, a lower stripper 150, and an upper stripper 160. The underrib forming section 57 also includes a second inner tool 230 and a second outer tool 240.

[0077] The second inner tool 230 has a recessed portion 231 formed inward on its side circumferential wall portion 232. The second outer tool 240 has a convex portion 241 formed inward on its side circumferential surface. The recessed portion 231 and the convex portion 241 are designed to be able to fit together with each other.

[0078] First, as shown in Figure 14(a), the lower stripper 150 is raised in the upward direction ZU, bringing it into contact with the wrapped portion 12 and the extended portion 13, while the second inner tool 230 is raised in the upward direction ZU, inserting its side peripheral wall portion 232 into the annular recess 20 formed by the inner fitting portion 14, the top portion 15, and the outer fitting portion 16.

[0079] In this state, as shown in Figure 14(b), the second inner tool 230 is further raised in the upward direction ZU until the upper end of the side circumferential wall portion 232 reaches the top portion 15. The recess 231 in the side circumferential wall portion 232 is positioned to be directly opposite either the end of the crimping portion 42 in the upward direction ZU of the outer fitting portion 16, or the outer fitting portion 16 where the crimping portion 42 is not formed.

[0080] Next, as shown in Figure 15(a) and Figure 16, which is an enlarged view of section C in Figure 15(a), the second outer tool 240 is brought close to the blank 10 in the upward direction ZU and then pushed inward. This allows the outer fitting portion 16 of the blank 10 to be sandwiched between the recess 231 formed inwardly on the side surface of the side circumferential wall portion 232 of the second inner tool 230 and the convex portion 241 formed inwardly on the side surface of the second outer tool 240. This sandwiching between the recess 231 and the convex portion 241 forms an underrib 17 that bends the outer fitting portion 16 inward, and furthermore, the enlarged diameter portion 18 and the downward extension portion 19 can be formed, completing the molding of the paper cover 1 in the desired shape.

[0081] Furthermore, by using pseudo-adhesion instead of adhesive bonding for the aforementioned crimping portion 42, the following effects are achieved. When forming the underrib 17 by sandwiching the recessed portion 231 and the convex portion 241, a force is applied to the crimping portion 42 as shown in the direction of the arrow in Figure 16. If this crimping portion 42 is completely bonded, the forces shown in the direction of the arrows in this crimping portion 42 will pull against each other, making it difficult to process the underrib 17. In contrast, by using pseudo-adhesion for the crimping portion 42, even when a force is applied due to the sandwiching between the recessed portion 231 and the convex portion 241, the crimping portion 42 can freely follow and move slightly in response to this force, and the underrib 17 can be easily processed without the pulling forces in the direction of the arrows mentioned above acting on each other.

[0082] Next, as shown in Figure 15(b), the second inner tool 230 and the second outer tool 240 are moved away from the blank 10 (paper cover 1) in the downward direction ZD. Then, the blank 10 (paper cover 1) is moved from the underrib forming section 57 to the discharge section 58 by rotating the turret 50.

[0083] Figure 17 shows an example of the configuration of the underrib forming section 57. In the underrib forming section 57, the second outer tool 240 is attached to the upper end of a lever 245 that extends upward in the ZU direction diagonally outward with the shaft 242 as the pivot point. The second outer tool 240 attached to the upper end of this lever 245 is movable outward or inward in accordance with the movement of the upper end of the lever 245 toward the outside or inward. The lever pushing section 751 is in contact with the outer surface of the lever 245 that extends upward in the ZU direction diagonally outward with the shaft 242 as the pivot point, via a roller 751a provided at its upper end. An elastic body 246, such as a spring, is interposed between the lever 245 and the second inner tool 230, and this elastic body 246 biases the lever 245 to be oriented upward in the ZU direction diagonally outward with the shaft 242 as the pivot point.

[0084] The lower side of the lever push-in portion 751 is connected to the drive unit 75. When the drive unit 75 is driven in the upward direction ZU, the lever push-in portion 751 also rises in the upward direction ZU accordingly. The outer surface of the lever 245 is pressed in the upward direction ZU via the roller 751a provided at the upper end of the lever push-in portion 751. Receiving this upward pressure in the upward direction ZU, the lever 245 moves inward via the shaft 242 that constitutes the pivot point, while resisting the biasing force by the elastic body 246 described above. As a result, the second outer tool 240 provided at the end of the lever 245 also moves inward, and by pushing the convex portion 241 formed inwardly on the side surface of the second outer tool 240 inward, the outer fitting portion 16 can be sandwiched between it and the recess 231.

[0085] At this time, the second outer tool 240 and the second inner tool 230 may be heated to about 70 to 90°C before clamping the outer fitting portion 16. This improves the shapeability when forming the under rib 17.

[0086] In the discharge section 58, as shown in Figure 18(a), the paper lid 1 obtained by molding the blank 10 is sucked into the plunger 140 and the upper stripper 160. From this state, as shown in Figure 18(b), the paper lid 1 is dropped and discharged to the outside by pushing the upper stripper 160 downward in the ZD direction.

[0087] Furthermore, the manufacturing apparatus 100 is equipped with blanking sections 51 to underrib forming sections 57 from the upstream area where blanks 10 are supplied from the feeder 60 to the downstream area where the discharge section 58 is located, and it is not essential to perform all processing operations in each of these sections. For example, as shown in Figure 3, when manufacturing a paper lid 1 equipped with a top plate section 11, a wrapping section 12, an outer extension section 13, an inner fitting section 14, and a ridge section 15, the manufacturing can be done with just the blanking section 51 and the pressing section 52, so only these may be installed in the manufacturing apparatus 100. Also, the bending section 53, heater section 54, mouthpiece processing section 55, rollout section 56, and underrib forming section 57 may be provided in the manufacturing apparatus 100 as appropriate according to the shape of the paper lid 1 to be manufactured, and components that are not used in actual manufacturing may be omitted.

[0088] When manufacturing a paper lid 1 using the manufacturing apparatus 100 according to the present invention, each manufacturing process from upstream to downstream is divided and assigned from the blanking section 51 to the underrib forming section 57, and the paper lid 1 is completed in its final form by gradually molding it at each manufacturing process while rotating the turret 50. As a result, after molding is completed at each manufacturing process, the turret 50 is rotated to move the blank 10 toward the next process, and the next blank 10 can be sequentially loaded and molded at that manufacturing process. In other words, blanks 10 can be sequentially loaded into the manufacturing apparatus 100 without waiting for the molding of one paper lid 1 to be completed, and multiple blanks 10 can be manufactured simultaneously and sequentially from the blanking section 51 to the underrib forming section 57. Therefore, compared to the conventional technology in which all molding processes are performed by one press machine and the next blank 10 cannot be loaded into the press machine until the molding of one paper lid is completed, it is possible to improve the overall molding speed.

[0089] In this invention, the example given is a case where the top plate portion 11 is located on the upward direction ZU side, and the enlarged diameter portion 18 and the downward extension portion 19 are located on the downward direction ZD side. However, the invention is not limited to this, and the product may be molded upside down. In other words, all components of the manufacturing apparatus 100 may be reversed upside down, and the product may be molded so that the top plate portion 11 is located on the downward direction ZD side, and the enlarged diameter portion 18 and the downward extension portion 19 are located on the upward direction ZU side.

[0090] Furthermore, in the above-described embodiment, the manufacturing apparatus 100 was described on the premise that it utilizes a feeder 60 that supplies blanks 10 and a turret 50 that processes the blanks 10 transported via the feeder 60 while transporting them in a circumferential direction, but it is not limited to this. That is, the description was based on the premise that each part that performs each manufacturing process is arranged in a roughly circular arc from the upstream where the blanks 10 are supplied from the feeder 60 to the downstream where the discharge section 58 is located, with the turret 50 as the center, but it is not limited to this. In other words, as long as the blanking section 51, pressing section 52, bending section 53, heater section 54, mouthpiece processing section 55, rollout section 56, and underrib forming section 57 are located in different places from the upstream where the blanks 10 are supplied from the feeder 60 to the downstream where the discharge section 58 is located, it is not essential that they be arranged in a roughly circular arc, they may be arranged in a straight line, and it is not necessarily essential that they be arranged in a regular shape.

[0091] 1 Paper lid 2 Paper container 10 Blank 11 Top plate 11a Top surface 11b Container surface 12 Encased part 13 Outer extension part 14 Inner fitting part 15 Top part 16 Outer fitting part 16a Extended end 16b Curled part 17 Underrib 18 Enlarged diameter part 19 Downward extension part 20 Annular recess 21 Inner surface of container part 28 Curled part 41 Drinking spout 41a Hinge part 41b Peripheral part 42 Crimping part 50 Turret 51 Blanking part 52 Press part 53 Folding and forming part 54 Heater part 55 Drinking spout processing part 56 Roll-out part 57 Underrib forming part 58 Discharge part 60 Feeder 61 Raw paper stand 71 Mandrel 73 Cylindrical cam 75 Drive unit 100 Manufacturing device 110 Bottom punch 120 Blank holder 130 Draw punch 132 Annular projection 133 Stepped section 135 Plunger 136 Extended projection 137 Elastic body 140 Plunger 146, 191 Recess 150 Lower stripper 160 Upper stripper 170 Stripper plate 180 Punch block 190 Curl tool 195 Heater 196 Heater nozzle 196a Outlet 200 Curl tool 201 Curling section 202 Drinking spout processing tool 210 First inner tool 211 Projection 220 First outer tool 221 Projection 230 Second inner tool 231 Recess 232 Side circumferential wall section 240 Second outer tool 241 Convex part 242, shaft 245, lever 751, lever push-in part 751a, roller OEP, peripheral edge

Claims

1. A method for manufacturing a paper lid, comprising: a blanking step of forming a top plate portion and a covered portion provided along the outer circumference of the top plate portion and extending in the second direction by pressing the central region in a first direction with a first pressing portion while holding down the periphery of a blank mainly made of paper; a first moving step of moving the blank to a press portion after separating the first pressing portion from the blank in a second direction opposite to the first direction; and a pressing step of pressing the central region with a second pressing portion while holding down the periphery of the blank moved to the press portion with a paper holding member, and then clamping the region separated outward from the outer circumference of the covered portion with a plunger formed in a concave shape toward the first direction and a draw punch formed in a convex shape toward the first direction, thereby forming an outward extension portion provided along the outer circumference of the covered portion and extending outward, an inner fitting portion provided along the outer circumference of the outward extension portion and extending in the first direction, and a top portion provided along the outer circumference of the inner fitting portion and extending outward.

2. The method for manufacturing a paper lid according to claim 1, characterized in that, in the pressing process described above, the blank is further driven in the first direction while being held between the plunger and the draw punch, and the region outside the top is sandwiched between the plunger and the side surface of the paper holding member to form an outer fitting portion that extends in the second direction.

3. A method for manufacturing a paper lid according to claim 2, comprising: a second moving step of moving the blank from the blank to the bending and forming step of inserting the second pressing portion and the draw punch in the second direction and moving the blank from the pressing portion to the bending and forming step of inserting the extended end of the outer fitting portion of the blank moved to the bending and forming step into a round groove-shaped curl tool and deforming it so that it is folded inward.

4. A method for manufacturing a paper lid according to claim 3, comprising: a third moving step of moving the curling tool away from the blank in the second direction and moving the blank from the bending forming section to the drinking spout processing section; and a drinking spout forming step of forming a drinking spout by pushing the drinking spout processing section toward the first direction toward the top plate section of the blank that has been moved to the drinking spout processing section, and deforming the extended end of the blank that has been folded inward by inserting it into a round groove-shaped curling section integrally provided with the drinking spout processing section, thereby forming a curled section that is curled in a substantially U-shape in cross-section.

5. A method for manufacturing a paper lid according to claim 4, comprising: a fourth moving step of moving the blank from the drinking spout processing portion and the curling portion in the second direction, and moving the blank from the drinking spout processing portion to the rollout portion; and a rollout step of bringing the outside of the curl portion on the blank moved to the rollout portion into contact with the first outer tool which has been brought close toward the first direction, and pushing the inside of the curl portion toward the outside with the first inner tool which has been brought close toward the first direction, thereby forming a crimped portion in which the substantially U-shaped cross-section curl portion is sandwiched between the first outer tool and the first inner tool and crimped together.

6. A method for manufacturing a paper lid according to claim 5, comprising: a fifth moving step of moving the first outer tool and the first inner tool away from the blank in the second direction, and moving the blank from the rollout portion to the underrib forming portion; and an underrib forming step of sandwiching the outer fitting portion of the blank moved to the underrib forming portion between a recess formed inwardly in the side circumferential surface of the second inner tool which has been brought closer in the first direction, and a convex portion formed inwardly in the side circumferential surface of the second outer tool which has been brought closer in the first direction, thereby forming an underrib in which the outer fitting portion is bent inward.

7. The method for manufacturing a paper lid according to claim 6, characterized in that, in the first moving step, the mandrel holding the blank is moved to the pressing section by a turret; in the second moving step, the mandrel holding the blank is moved to the bending section by a turret; in the third moving step, the mandrel holding the blank is moved to the spout processing section by a turret; in the fourth moving step, the mandrel holding the blank is moved to the roll-out section by a turret; and in the fifth moving step, the mandrel holding the blank is moved to the under-rib forming section by a turret.

8. The method for manufacturing a paper lid according to claim 6, characterized in that, in the underrib forming step, the second outer tool provided at the end of a lever biased diagonally outward from a pivot point by an elastic body interposed between it and the second inner tool is used, and the lever, which is pressed in the first direction by the lever pushing portion, moves inward via the pivot point, thereby pressing the outer fitting portion from the outside with the second outer tool provided at the end of the lever.

9. The method for manufacturing a paper lid according to claim 5, characterized in that in the rollout process described above, the curl portion, which has a substantially U-shaped cross-section, is sandwiched between the first outer tool and the first inner tool and bonded or pseudo-bonded to each other to form a compressed portion.

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