Method for manufacturing paper lid

Abstract

[Problem] To improve the whole shaping speed in manufacturing a paper lid having a flat lid shape. [Solution] A method for manufacturing a paper lid includes: a blanking step for forming a top plate part 11, an inner fitting part 14, and a top part 15 by holding a central region of a blank 10, while holding the circumferential edge, in a second direction by mean of an upper stripper 160 from a first direction side and a plunger 140 having an extension part 145 extended to the second direction side and having a cutout recessed part 146 cut out in a recessed shape in the first direction; a first moving step for moving the blank 10 to a press part 52; and a pressing step for forming an outer fitting portion 16 by clamping the central region while holding the circumferential edge, of the blank 10, which has been moved to the press part 52, with a paper-holding member 110, pushing an annular projection 132 provided on the outer circumference of a second draw punch 130 down to the top part 15 of the blank 10, driving the second draw punch 130 in the first direction, and clamping a region outside the top part 15 of the blank 10 between the second draw punch 130 and the side surface of the paper-holding member 110.

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 a lid with a top plate bulging upward. Among them, for types that drink using a straw, such as cold beverages, the flat lid shape is often applied.

[0004] Such paper lids were generally manufactured by a press machine as shown in Patent Document 1, for example. With this press machine, while holding the periphery of the blank, the draw die, blank holder, draw punch, plunger, etc. are pushed upward or downward to form the top plate portion, the wrapped portion, and further the inner fitting portion and outer fitting portion for fitting with the paper container.

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

[0006] However, according to the disclosed technology of Patent Document 1, it was premised that the entire molding process from one blank to the completion of molding one paper lid was performed by one press machine. For this reason, until the molding of one paper lid is completed, the next blank cannot be loaded into that press machine, and since it takes a waiting time for that amount, there is a problem that the molding speed cannot be improved. Also, when each process is shared and molded by a plurality of press machines, there is a problem that the time required to transport the blank during molding between the press machines cannot improve the overall molding speed.

[0007] Therefore, the present invention has been devised in view of the above-described problems, and the object is to provide a method for manufacturing a paper lid capable of improving the overall molding speed in manufacturing a paper lid having a flat lid shape.

[0008] The paper lid manufacturing method according to the present invention solves the above-mentioned problems by pressing a plunger in the second direction while holding down the periphery of a blank mainly made of paper, the plunger having a first pressing portion from the first direction side, an extension portion extending outward from the first pressing portion to the second direction opposite to the first direction, and a notched recess cut out in a concave shape on the outside of the extension portion toward the first direction, thereby forming a top plate portion, an inner fitting portion provided along the outer circumference of the top plate portion and extending toward the first direction, and a top portion provided along the outer circumference of the inner fitting portion and extending toward the outside; a first moving step of moving the blank to a press section; and the press section The method is characterized by a pressing step which involves pressing the periphery of the blank, which has been moved to a certain position, between paper-holding members, while pressing the central region between a third pressing portion from the first direction and a fourth pressing portion from the second direction, and pushing an annular projection that protrudes toward the first direction on the outer circumference of the second draw punch located outside the fourth pressing portion toward the top of the blank toward the first direction, driving the third pressing portion, the fourth pressing portion and the second draw punch toward the first direction, and forming an outer fitting portion that extends toward the second direction by sandwiching the region outside the top of the blank between the second draw punch and the side surface of the paper-holding member.

[0009] According to the present invention, based on the above configuration, 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 having to wait until the molding of one paper lid is completed, and multiple blanks can be manufactured simultaneously and sequentially from the blanking section to the underrib forming section. Therefore, compared to 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 is a diagram for explaining the subsequent manufacturing process in the blanking section. Figure 8 is a diagram for explaining the preceding manufacturing process in the pressing section. Figure 9 is a diagram for explaining the subsequent manufacturing process in the pressing section. Figure 10 is a diagram for explaining the preceding manufacturing process in the underrib forming section. Figure 11 is a diagram for explaining the subsequent manufacturing process in the underrib forming section. Figure 12 illustrates a configuration in which a blank (paper lid) is moved from the underrib forming section to the discharge section by rotating a turret. Figure 13 illustrates a configuration in which the molded paper lid is dropped and discharged to the outside. Figure 14 illustrates a method for manufacturing a paper lid with a curled section formed inward in a roughly U-shaped cross-section. Figure 15 illustrates a method for manufacturing a paper lid with a curled section formed outward in a roughly U-shaped cross-section. Figure 16 illustrates a method for manufacturing a paper lid with a crimped 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, 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, such as 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 is 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 (inner fitting portion 14, top portion 15, outer fitting portion 16, under rib 17, enlarged diameter portion 18, and downward extension portion 19) is 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 inner fitting portion 14 is provided on the peripheral edge OEP of the paper cover 1, along the outer circumference of the top plate portion 11, and extends upward (direction X3). This inner fitting portion 14 is continuous with the top plate portion 11. 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.

[0018] 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).

[0019] 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.

[0020] The under rib 17 is formed in continuous with the outer fitting portion 16 and is bent inward (direction X4). The under rib 17 includes a curved surface that is concave inward (direction X4). The enlarged diameter portion 18 extends downward (direction X2) from the outer circumference of the under rib 17 and then enlarges outward (direction X1). The downward extension portion 19 extends downward (direction X2) from the lower end of the enlarged diameter portion 18.

[0021] In other words, in the cross-section of the paper lid 1, it bends upward (direction X3) at the inner fitting portion 14, outward (direction X1) at the top portion 15, downward (direction X2) at the outer fitting portion 16, and inward (direction X2) at the underrib 17, resulting in a curved surface that is concave inward (direction X4). Furthermore, it is extended outward (direction X1) at the enlarged diameter portion 18 and further extended downward (direction X2) at the downward extension portion 19. That is, each of the top plate portion 11, inner fitting portion 14, top portion 15, outer fitting portion 16, underrib 17, enlarged diameter portion 18, and downward extension portion 19 is obtained from a single blank 10.

[0022] In a paper lid 1 of this shape, the boundaries between the top plate portion 11 and the inner fitting portion 14, the boundary between the inner fitting portion 14 and the top portion 15, the boundary between the top portion 15 and the outer fitting portion 16, the boundary between the outer fitting portion 16 and the under rib 17, the boundary between the under rib 17 and the enlarged diameter portion 18, and the boundary between 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.

[0023] 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, an inner fitting portion 14, and a top 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.

[0024] Next, an example of a method for manufacturing the paper lid 1 to which the present invention is applied will be described.

[0025] (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.

[0026] 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.

[0027] 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.

[0028] The turret 50 is equipped with a blanking section 51, a pressing section 52, 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 blanking section 51 to the underrib forming section 57 of the turret 50 are arranged to form a roughly circular arc. 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.

[0029] 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 completed by gradually molding it at each manufacturing process while rotating the turret 50. In other words, in this turret 50, the blank 10 is blanked in the blanking section 51 and then rotated and transported to the press section 52. Next, the blank 10 is press-molded in the press section 52 and then rotated and transported to the underrib forming section 57. Next, the underrib 17 is formed in the underrib forming section 57 and then rotated and transported to the discharge section 58.

[0030] The discharge unit 58 is supplied with paper lids 1 that have been molded in the turret 50. The discharge unit 58 then discharges the supplied paper lids 1 to the outside.

[0031] Figure 5 is a schematic cross-sectional view of the manufacturing apparatus 100, with the blanking section 51 as an example.

[0032] The manufacturing apparatus 100 includes a mandrel 71 mounted on the turret 50, a cylindrical cam 73 mounted on 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 has 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., 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.

[0033] Next, we will explain in detail each manufacturing process from the blanking section 51 to the underrib forming section 57.

[0034] 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.

[0035] Specifically, when manufacturing the 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 at least the bottom punch 110 and the blank holder 120, and as shown in Figure 6(b), 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.

[0036] In this blanking process, instead of pressing the periphery of the blank 10 with the stripper plate 170 and punch block 180, a sharpened knife edge 180a may be formed on the corner of the punch block 180, and the blank 10 may be cut through the knife edge 180a as the bottom punch 110, which holds the blank 10 in place, and the blank holder 120 are pushed upward in the ZU direction.

[0037] In Figure 6(b), the blank 10 is held in a nearly horizontal position by the bottom punch 110, blank holder 120, lower stripper 150, and upper stripper 160, and the draw punch 130 and plunger 140 may or may not be in contact with the blank 10.

[0038] The cross-sectional shape of the draw punch 130, located on the outside of the lower stripper 150, has an annular projection 132 that protrudes upward in the ZU direction on its outer circumference, and a notched recess 135 is formed inside the annular projection 132. This makes it possible to form the inner fitting portion 14 and the top portion 15 of the blank 10 so that their external shape corresponds to the annular projection 132 and the notched recess 135.

[0039] Furthermore, the plunger 140, which faces the draw punch 130 in the upward direction ZU, is provided with an extension portion 145 that extends toward the downward direction ZD at the peripheral end, and the outer end is provided with a notched recess 146 that is cut out in a concave shape toward the upward direction ZU. This notched recess 146 may be curved and is shaped to fit precisely with the annular projection 132. Similarly, the extension portion 145 may also be curved and is shaped to fit precisely with the notched recess 135.

[0040] The plunger 140, which has this shape, is pushed down in the downward direction ZD together with the upper stripper 160 as shown in Figure 7(a). Simultaneously with, or before, the downward pushing down of the plunger 140, the lower stripper 150 is also pushed down in the downward direction ZD. During this downward pushing stage, the blank 10 is held in place by the bottom punch 110 and the blank holder 120.

[0041] As a result, the blank 10 is bent and formed from the top plate portion 11 in the upward direction ZU in the figure, forming portions that correspond precisely to the inner fitting portion 14 and the top portion 15. At this time, the annular projection 132 of the draw punch 130 is fitted into the notched recess 146 of the plunger 140, and the blank 10 is formed precisely along the cross-sectional shape of the notched recess 146 and the annular projection 132, and also along the cross-sectional shape of the notched recess 135 and the extension portion 145 that are fitted together. Therefore, by pre-forming the notched recess 146, the annular projection 132 and the notched recess 135 and extension portion 145 to the desired cross-sectional shape corresponding to the inner fitting portion 14 and the top portion 15, the blank 10 can also be finished to have the inner fitting portion 14 and the top portion 15 corresponding to these cross-sectional shapes.

[0042] Note that in the blanking portion 51, the plunger 140 is only pushed downward in the ZD direction together with the upper stripper 160, and the cross-sectional shapes of the fitting portion 14 and the top portion 15 corresponding to the notch recess 146 and the extension portion 145 can be formed. That is, in forming the cross-sectional shapes of the fitting portion 14 and the top portion 15, it is not essential to sandwich the notch recess 146, the annular protrusion 132, the notch recess 135, and the extension portion 145 with each other.

[0043] Next, as shown in FIG. 7(b), the blank 10 is separated from the bottom punch 110, the lower stripper 150, and the draw punch 130 in the ZD direction. Next, by rotating the turret 50, the blank 10 is moved from the blanking portion 51 to the pressing portion 52.

[0044] As shown in FIG. 8(a), the pressing portion 52 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. Note that the components and members after this pressing portion 52 are not completely the same as the components and members in the above-described blanking portion 51, but the same reference numerals are used for the same types of components and members for description. The draw punch 130 has an annular protrusion 132 and a notch recess 135, and the plunger 140 has an extension portion 145 and a notch recess 146.

[0045] After moving the blank 10 to the pressing portion 52, as shown in FIG. 8(b), the bottom punch 110 is raised in the ZU direction to hold its periphery with the blank holder 120, and the draw punch 130 and the lower stripper 150 are raised in the ZU direction until they contact the blank 10. As a result, the blank 10 is sandwiched between the notch recess 146 and the annular protrusion 132 that are fitted to each other, and between the notch recess 135 and the extension portion 145.

[0046] Next, as shown in Fig. 9(a), with the periphery of the blank 10 held by the bottom punch 110 and the blank holder 120, the plunger 140, upper stripper 160, draw punch 130, and lower stripper 150 that sandwich the blank 10 are driven to push upward in the ascending direction ZU. As a result, the periphery of the blank 10 held 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 annular protrusion 132 on the draw punch 130. The outer side surface of this annular protrusion 132 is designed to be in surface contact with the side surface of the blank holder 120 or to face each other and be close. Therefore, by driving the plunger 140, upper stripper 160, draw punch 130, and lower stripper 150 that sandwich the blank 10 to push upward in the ascending direction ZU, the blank 10 itself is pulled in the ascending direction ZU, and as a result, its periphery is also sandwiched between the side surface of the blank holder 120 and the outer side surface of the annular protrusion 132 on the draw punch 130. Since the side surface of the blank holder 120 and the outer side surface of the annular protrusion 132 on the draw punch 130 extend in the ascending direction ZU (descending direction ZD), the periphery of the blank 10 sandwiched between them can also be extended in the ascending direction ZU (descending direction ZD). As a result, in the blank 10, a portion corresponding to the outer fitting portion 16 can be molded. At this time, depending on the diameter of the blank 10, if a part of the periphery of the blank 10 is sandwiched between the bottom punch 110 and the blank holder 120, the periphery of the blank 10 after molding may have a shape extended outward.

[0047] Next, as shown in Fig. 9(b), the draw punch 130 and the lower stripper 150 are separated from the blank 10 in the descending direction ZD. Next, by rotating the turret 50, the blank 10 is moved from the press section 52 to the under-rib forming section 57.

[0048] As shown in Figure 10(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 an inner tool 230 and an outer tool 240.

[0049] The inner tool 230 has a concave recess 231 on the inside of the side circumferential wall portion 232. The inner tool 230 is also provided with a stepped portion 233 that expands in diameter outward from the side circumferential wall portion 232 and extends downward in the ZD direction.

[0050] The outer tool 240 has an upper part that is tapered inward to form a stepped portion 243, and a convex portion 241 is formed on the side surface of the stepped portion 243, which is convex in the inner side. The recess 231 and the convex portion 241 are designed to be able to fit together.

[0051] In this state, as shown in Figure 10(b), the 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 directly opposite the outer fitting portion 16.

[0052] Next, as shown in Figure 11(a) and Figure 11(b), which is an enlarged view of section C, the 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 inner tool 230 and the convex portion 241 formed inwardly on the side surface of the outer tool 240. This sandwiching between the recess 231 and the convex portion 241 forms an under rib 17 that bends the outer fitting portion 16 inward.

[0053] Furthermore, by sandwiching the blank 10 between the stepped portion 233 and the stepped portion 243, it can be molded into the corresponding shape, the enlarged diameter portion 18 and the downward extension portion 19 can be molded, and the molding of the paper cover 1 in the desired shape is completed.

[0054] Next, as shown in Figure 12(a), the inner tool 230, outer tool 240, and lower stripper 150 are separated from the blank 10 (paper cover 1) in the downward direction ZD. Next, the blank 10 (paper cover 1) is moved from the underrib forming section 57 to the discharge section 58 by rotating the turret 50.

[0055] In the discharge section 58, as shown in Figure 13(a), the paper lid 1 obtained by molding the blank 10 is being sucked into the plunger 140 and the upper stripper 160. From this state, as shown in Figure 13(b), the paper lid 1 is dropped and discharged to the outside by pushing the upper stripper 160 downward in the ZD direction.

[0056] Furthermore, according to the present invention, a paper lid 1 may be manufactured in which a curled portion 24a is formed by curling inward in a substantially U-shaped cross-section from the lower end of the downward extension portion 19, as shown in Figure 14(a). When manufacturing such a paper lid 1, before completing the process in the underrib forming portion 57 and moving it to the discharge portion 58, the blank 10 is moved to the curl forming portion 59 equipped with a curling tool 200 as shown in Figure 14(b).

[0057] The curling tool 200 has a rounded groove-shaped curling portion 201. The curling portion 201 is designed so that when pushing up, the curling portion 201 is located in the downward extension portion 19 of the blank 10.

[0058] After moving the blank 10 to the curl-forming section 59, the curl tool 200 is pushed upward in the upward direction ZU. This deforms the downward extension 19 of the blank 10 that has entered the curling section 201, and a curled section 24a with a roughly U-shaped cross-section can be formed.

[0059] Alternatively, as shown in Figure 15(a), a paper cover 1 may be manufactured with a curled portion 24b formed by curling outward from the lower end of the downward extension portion 19 in a roughly U-shaped cross-section. Similarly, in this case, as shown in Figure 15(b), the curled portion 24b is formed using a curling tool 200 having a round groove-shaped curling portion 202. The curling portion 202 is designed so that when pushed up, the curling portion 202 is positioned in the downward extension portion 19 of the blank 10. By deforming the downward extension portion 19 of the blank 10 that is inserted into the curling portion 202, the curled portion 24b can be formed in the same way.

[0060] Furthermore, according to the present invention, a paper cover 1 may be manufactured in which a crimped portion 42 is formed by folding back and crimping from the lower end of the downward extension portion 19, as shown in Figure 16(a).

[0061] When manufacturing such a paper lid 1, before completing the process in the curl forming section 59 and moving it to the discharge section 58, the blank 10 is moved to a rollout 63 equipped with an inner crimping tool 210 and an outer crimping tool 220 as shown in Figure 16(b).

[0062] The inner crimping tool 210 has a crimping surface 210a. The outer crimping tool 220 has a crimping surface 220a located opposite to the crimping surface 210a.

[0063] After moving the blank 10 to the rollout 63, the curl portion 24a is inserted between the crimping surface 210a of the inner crimping tool 210 and the crimping surface 220a of the outer crimping tool 220, which are spaced apart from each other. Then, either or both of the inner crimping tool 210 and the outer crimping tool 220 are activated to bring the crimping surfaces 210a and 220a closer together and sandwich the curl portion 24a. As a result, the curl portion 24a becomes a crimped portion 42 with a flattened shape formed by crimping two substantially U-shaped sections together. The formation of such a crimped portion 42 can be easily achieved by preheating the outer fitting portion 16, the curl portion 24a, and the downward extension portion 19 in a heater (not shown) to melt the resin. Alternatively, instead of melting the resin, the parts may be crimped together via an adhesive that has been pre-applied to the outer fitting portion 16, the curl portion 24a, and the downward extension portion 19. Alternatively, the crimped portion 42 may be formed by a so-called pseudo-bonding method, which involves bonding based on the force applied by pressure, without using adhesive or molten resin. In this pseudo-bonding method, adhesive may be used in part. In this pseudo-bonding method, adhesive may be used in amounts less than that normally used, or it may not be used at all.

[0064] Furthermore, the manufacturing apparatus 100 is equipped with blanking sections 51 to underrib forming sections 57 from the upstream where the blanks 10 are supplied from the feeder 60 to the downstream where they reach the discharge section 58, 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, an internal fitting section 14, and a top section 15, the manufacturing can be done with just the blanking section 51 and the pressing section 52, so only these may be mounted on the manufacturing apparatus. Similarly, when manufacturing a paper lid 1 equipped with a top plate section 11, an internal fitting section 14, a top section 15, and an external fitting section 16, the manufacturing can be done with just the blanking section 51 and the pressing section 52, so only these may be mounted on the manufacturing apparatus.

[0065] Furthermore, the under-rib forming section 57 may be provided within 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.

[0066] According to the present invention, which manufactures the paper lid 1 using the manufacturing apparatus 100 described above, 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 at each manufacturing process while rotating the turret 50. As a result, after molding is completed in 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 in that manufacturing process. In other words, blanks 10 can be sequentially loaded into the manufacturing apparatus 100 without waiting until the molding of one paper lid 1 is 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.

[0067] 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.

[0068] Furthermore, in the above-described embodiment, the manufacturing apparatus 100 was described on the premise that it utilizes a feeder 60 for supplying blanks 10 and a turret 50 for processing the blanks 10 transported via the feeder 60 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 substantially 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, the pressing section 52, and the 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 substantially circular arc, they may be arranged in a straight line, and it is not necessarily essential that they be arranged in a regular shape.

[0069] 1 Paper lid 2 Paper container 10 Blank 11 Top plate 11a Top surface 11b Container surface 14 Inner fitting part 15 Top part 16 Outer fitting part 17 Underrib 18 Enlarged diameter part 19 Downward extension part 20 Annular recess 21 Inner surface of container part 24 Curl part 28 Curl part 41 Drinking spout 41a Hinge part 41b Peripheral part 42 Crimping part 50 Turret 51 Blanking part 52 Press part 57 Underrib forming part 58 Discharge part 59 Curl forming part 60 Feeder 61 Raw paper stand 63 Rollout 71 Mandrel 73 Cylindrical cam 75 Drive unit 100 Manufacturing equipment 110 Bottom punch 120 Blank holder 130 Draw punch 132 Annular projection 135 Notched recess 140 Plunger 145 Extension 146 Notched recess 150 Lower stripper 160 Upper stripper 170 Stripper plate 180 Punch block 200 Curling tool 201 Curling section 202 Curling section 210 Inner crimping tool 220 Outer crimping tool 230 Inner tool 231 Recess 232 Side periphery wall section 233 Stepped section 240 Outer tool 241 Protrusion 243 Stepped section OEP Peripheral edge

Claims

1. A blanking process in which a plunger having a first pressing portion from the first direction side, an extension portion extending outward from the first pressing portion to the second direction opposite to the first direction, and a notched recess cut out in a concave shape toward the first direction on the outside of the extension portion, is pressed in the second direction while holding down the periphery of a blank mainly made of paper, thereby forming a top plate portion, an inner fitting portion provided along the outer circumference of the top plate portion and extending toward the first direction, and a top portion provided along the outer circumference of the inner fitting portion and extending toward the outside; and a first moving process in which the blank is moved to the press section. A method for manufacturing a paper cover, comprising a pressing step, in which the periphery of the blank moved to the press section is held in place by being sandwiched between paper-holding members, the central region is sandwiched by a third pressing section from the first direction and a fourth pressing section from the second direction, an annular projection that protrudes toward the first direction on the outer circumference of the second draw punch located outside the fourth pressing section is pushed toward the top of the blank in the first direction, the third pressing section, the fourth pressing section and the second draw punch are driven toward the first direction, and the region outside the top of the blank is sandwiched between the second draw punch and the side surface of the paper-holding member to form an outer fitting portion extended toward the second direction.

2. The method for manufacturing a paper lid according to claim 1, characterized in that, in the blanking step, the blank is further clamped by the first pressing part and the second pressing part from the second direction side, and the first pressing part and the second pressing part are pushed in the second direction, and in the first moving step, the second pressing part is separated from the blank in the second direction, and then the blank is moved to the press part.

3. A method for manufacturing a paper lid according to claim 1, comprising: a second moving step of moving the blank to an underrib forming section after separating the fourth pressing section and the second draw punch from the blank in a second direction; and an underrib forming step of pressing the outer fitting section of the blank, which has been moved to the underrib forming section, from the inside with a first inner tool having a concave recess formed on its side surface that has been brought close in the first direction, and pressing it from the outside with a first outer tool having a convex protrusion formed on its side surface that has been brought close in the first direction, thereby forming an underrib that bends the outer fitting section inward.

4. The method for manufacturing a paper lid according to claim 3, characterized in that, in the first moving step, the mandrel holding the blank is moved to the pressing section by a turret, and in the second moving step, the mandrel holding the blank is moved to the underrib forming section by a turret.

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