JP2009166078A - Method of providing double structure flange on cup-shaped container, and forming die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flange which has strength necessary to open and to mount an overcap, which has no risk that a hand and a mouth are cut by a flange edge and which is combinable with a filling and sealing machine for synthetic resin containers on a cup-shaped container made of a composite material of an aluminum foil and synthetic resin coating layers. <P>SOLUTION: In the method for providing the flange having double structure on the cup-shaped container, the composite material (4) consisting of the core layer (1) of the aluminum foil, an inside unstretched polypropylene coating layer (2) and an outside unstretched polypropylene coating layer (3) is used, the peripheral part (5a) of a vertically bent flange in which the peripheral part (5a) of the flange (5) is bent vertically and downward is provided on a tapered cup-shaped container (A). First, the vertically bent flange peripheral part (5a) is bent into an inward inclined-shape with an inward inclined-shape bending forming die (E). Next, the double structure flange (6) is made by pressurizing the inward inclined-shape flange peripheral part (5a) to the side of a horizontal flange base part (5b) with a forming die (F) for pressurization. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

   The present invention relates to a method of providing a double-structured flange on a cup-shaped container and a molding die used in this method.

  In this specification, the flange base portion refers to approximately half of the outer periphery of the container before folding, and the flange peripheral portion refers to the remaining approximately half.

  Although there is a synthetic resin container as the container, in order to maintain the flavor of the contents, a composite material container composed of an aluminum foil layer and a double-sided synthetic resin coating layer as shown in Patent Document 1 below. Is better.

 However, in the case of the above composite material container, since the material thickness is thinner and the flange strength is weaker than that of the synthetic resin container, when the heat-sealed lid is opened, the flange can also be opened to be lifted together. In the case of a beverage container, the lid made of aluminum foil is stabbed with a straw so that the manufacturer can attach a synthetic resin overcap to the lid so that dust does not adhere to the top of the lid. There was a problem that the flange was bent and could not be fitted over the mouth of the container.

  Therefore, when the aluminum foil or the synthetic resin coating layer of the composite material is thickened, the manufacturing cost increases, and when the thickness is increased, there is a possibility that the hand or mouth is cut at the edge of the flange having increased strength.

In order to solve this problem, a curl edge may be formed on the flange of the container as shown in Patent Document 2 below.
JP 2005-153894 A JP 2007-111501 A

  If the curled edge is formed on the flange, there is no risk of cutting the hand or mouth at the end of the flange, but considering the flange width necessary for heat sealing with the lid made of aluminum foil having a heat sealing material layer on the lower surface, Since the curl edge is larger than the flange of the synthetic resin container, it becomes difficult to use it as a filling sealer for the synthetic resin container. Because the filling and sealing machine for synthetic resin containers has a flat upper and lower mold surface, if there is a curled edge on the flange, the upper and lower surfaces of the flat portion of the flange and the flat surfaces of the upper and lower molds facing this surface This is because a gap is generated in the gap and a sealing failure occurs.

  The present invention is a container using a composite material of an aluminum foil and a synthetic resin coating layer, has a strength required for opening or mounting an overcap, has no fear of cutting a hand or mouth at the flange edge, and is a synthetic resin It is an object of the present invention to provide a method of providing a cup-shaped container with a double-structured flange that can be used as a container filling and sealing machine, and a molding die used in this method.

  A method of providing a double-structured flange on a cup-shaped container according to the invention of claim 1 uses a composite material consisting of an aluminum foil core layer and a synthetic resin coating layer formed on both sides thereof, and has a tapered cup shape. The container is provided with a vertical bent flange peripheral portion where the flange peripheral portion is vertically bent downward. First, the vertical bent flange peripheral portion is bent inwardly with an inwardly inclined bending mold, The peripheral edge of the flank flange is pressed against the horizontal flange base with a pressing mold to form a double-structured flange.

  According to a second aspect of the present invention, there is provided a method of providing a double-structured flange on the cup-shaped container according to the first aspect, wherein the peripheral edge of the flange is bent vertically downward on the tapered cup-shaped container. First, after forming a tapered cup-shaped container having a horizontal flange slightly larger than a predetermined width for obtaining a double-structured flange, the peripheral edge of the horizontal flange is trimmed to form a horizontal flange having a predetermined width. Next, the peripheral edge portion of the horizontal flange having a predetermined width is bent at a substantially right angle to the lower side to form a vertically bent flange peripheral edge portion.

  An inwardly inclined bending mold according to the invention of claim 3 penetrates through a punch having an upper end peripheral edge having a diameter substantially equal to the peripheral edge of the double structure flange, a cylindrical die with a top wall, and a top wall of the die. It consists of a vertical bar-shaped container holder that can be adjusted dynamically, on the inner peripheral surface of the tip of the cylindrical die, a relatively gentle inclined surface upward from the lower end, a vertical surface having an inner diameter substantially equal to the diameter of the tip of the punch, and A relatively steep inclined surface is formed.

  According to a fourth aspect of the present invention, in the inwardly inclined bending metal mold according to the third aspect of the present invention, on the basis of the vertical surface, the inclined surface has a gentle inclination angle of 3 to 15 ° and the steep inclined surface of 20 to 60 °. There is something.

  The pressing mold according to the invention of claim 5 penetrates through the punch having the upper end periphery larger in diameter than the periphery of the double structure flange, the top wall of the cylindrical die and the top wall of the die, and can be adjusted up and down. It consists of a vertical bar-shaped container holder, and a downward stepped portion is formed on the inner peripheral surface of the tip of the die, and the downward stepped portion is lower than the vertical height of the double structure flange and slightly wider than the peripheral edge of the double structure flange. In addition, a gap is formed between the lower surface of the die and the upper surface of the punch during pressurization, and the total height of the gap and the stepped portion is 2 to 5 times the thickness of the composite material. It is what is.

  In the invention of claim 4, the inclination angle is limited to 3 to 15 ° with a gentle inclination surface on the basis of the vertical surface. If it is less than 3 °, the peripheral edge of the vertical bending flange is not smoothly guided to the vertical surface, If it exceeds 15 °, it will strike against the inclined surface and it will not be guided smoothly as well, so it is preferably 7 to 10 °. The reason for limiting to 20 to 60 ° on a steeply inclined surface is that if it is less than 20 °, bending molding becomes severe and the peripheral edge of the vertical bending flange may be damaged. If it exceeds 60 °, bending molding is weak. Since there is a possibility that unreasonable pressure molding may occur in the process, the angle is preferably 30 to 50 °.

  In the invention of claim 5, the downward stepped portion or groove has a width lower than the vertical height of the double structure flange and slightly larger than the peripheral edge of the double structure flange. By ensuring roundness without variation, the overcap can be securely attached, and even if there is a gap between the lower surface of the die and the upper surface of the punch during pressurization, This is because the peripheral edge of the flange can be sufficiently pressurized. The reason why a gap is formed between the lower surface of the die and the upper surface of the punch during pressurization is that both molds are in contact with each other so as not to be damaged. And the total of this gap and the height of the stepped part is limited to 2 to 5 times the thickness of the composite material, and if it is less than 2 times, there is no gap between the upper and lower layers of the double-structured flange, Since the thickness of the composite material is less than the thickness of the composite material itself, there is a risk of material cracking at the flat or folded end of the flange. Therefore, when the lid is heat-sealed to the flange, the pressure applied will be uneven and cause a seal failure, and when the overcap is hooked onto the flange, the flange folded back down This is because the inclination angle of the cross section of the peripheral edge is too large, which causes a mounting failure.

A tapered cup-shaped container having a flat flange is manufactured by the method disclosed in Patent Document 1. That is, when forming a tapered cup-shaped container equipped with a flange by deep drawing a laminated sheet composed of an aluminum foil core layer and a synthetic resin coating layer formed on both surfaces thereof, the deep drawing process is A multi-stage process comprising a bottomed straight cylinder forming process for forming a blank into a bottomed straight cylinder and a bottomed tapered cylinder forming process for forming the bottomed straight cylinder following this process into a bottomed cylindrical cylinder. It is a process. The bottomed straight cylindrical body forming step includes a first step of forming a blank into a bottomed straight cylindrical shape, and a first step of further deep drawing the bottomed straight cylindrical body obtained in the first step. Alternatively, it consists of a plurality of steps. In the bottomed tapered cylinder forming step, the taper angle applied to the cylinder is 1 to 5 °, and the drawing ratio is 80% or more.

  To make a double structure by folding the flange periphery of a tapered cup-shaped container downward, first, a tapered cup shape having a vertically bent flange periphery where the periphery of the horizontal flange is bent substantially perpendicularly downward In addition to the method according to the second aspect of the present invention, there is a method of forming a tapered cup-shaped container having a vertically bent flange peripheral edge from the beginning. The latter method has a problem of non-uniformity in the vertical length of the peripheral edge of the vertical bending flange due to the non-uniformity of material elongation at the time of molding. Therefore, the former method is preferable.

  According to the method of providing a double-structured flange in the cup-shaped container of the present invention, a tapered cup-shaped container is formed using a composite material consisting of an aluminum foil core layer and a synthetic resin coating layer formed on both sides thereof. The peripheral edge of the flange is bent vertically downward, and the peripheral edge of the vertical bent flange is first bent inwardly with an inwardly inclined bending mold, and then inwardly. Since the peripheral edge of the inclined flange is pressed against the horizontal flange base with a pressing mold to form a double-structured flange, it has the strength necessary for opening or attaching an overcap and is hand-held at the flange edge. It is possible to easily obtain a double-structured flange that can be used as a filling and sealing machine for synthetic resin containers without the risk of cutting the mouth and the mouth.

  In order to specifically explain how the present invention is carried out, examples are given below.

For convenience, a cup-shaped container provided with a double-structured flange by the method of the present invention shown in FIGS. 1 to 3 will be described in advance.
The tapered cup-shaped container (A) is formed on the outer surface of an unstretched polypropylene coating layer (2) made of an aluminum foil core layer (1) having a thickness of 120 μm and a film having a thickness of 200 μm formed on the inner surface thereof. The composite material (4) (see FIG. 3) made of an unstretched polypropylene coating layer (3) made of a film having a thickness of 30 μm was obtained by cold multistage deep drawing, and the flange (5) The peripheral edge portion (5a) is folded downward and is provided with a flange (6) having a width of 5 mm which has a double structure with the flange base portion (5b).

  The thickness of the composite material is selected from the range of 0.1 to 0.8 mm. This is because if the thickness is less than 0.1 mm, the strength of the entire container is insufficient, and even if the thickness exceeds 0.8 mm, the effect is not changed and only the cost is increased. .2 to 0.6 mm.

In the above, the flange peripheral part (5a) folded down is a length smaller than ½ of the width of the flange (5) before folding back. In addition, the vertical distance (L ₁ ) from the upper surface of the flange base portion (5b) to the lower edge of the front end of the flange peripheral portion (5a) shown by the solid line is about 2.4 times the thickness of the composite material (4). 0.85 mm. The flange peripheral part (5a) indicated by the solid line is folded back so as to be in a horizontal state, but the flange peripheral part (5a) indicated by the chain line is in an inwardly inclined state because it attempts to return to the original state. The vertical distance (L ₂ ) from the upper surface of the flange base (5b) to the lower edge of the flange periphery (5a) is 1.5 mm, which is about 4.3 times the thickness of the composite (4). is there.

  The flange peripheral portion (5b) folded back is selected from those having a width equal to or more than 1/3 of the flange lower surface width before being folded and not more than a length just reaching the outer peripheral surface of the container. This is because when the length is less than 1/3, when the lid (31) is heat-sealed to the upper surface of the double-structured flange (6), the length of the double portion is too short, Sealing failure occurs due to the difference in the pressure applied to the part, and conversely, the length of the flange peripheral part (5b) folded back is longer than the length that the outer peripheral surface of the container (A) reaches exactly. This is because the tip bends downward and the fitting into the flange receiver of the filling and sealing machine becomes worse.

  FIG. 4 shows a state in which the overcap (B) is attached to the double-structured flange (6). 3 and 4, (31) is an aluminum lid having a heat sealing material layer on the lower surface.

  A method of folding the flange peripheral portion (5a) of the tapered cup-shaped container (A) downward to form a double structure flange (6) will be described below.

  First, after forming a tapered cup-shaped container (A) having a horizontal flange (7) slightly larger than a predetermined width for obtaining a double-structured flange, a mold for edge cutting shown in FIGS. 5 and 6 ( Using C), the edge (7a) slightly larger than the predetermined width of the horizontal flange (7) is trimmed. The edge cutting mold (C) is movable up and down tightly fitted in a punch (8), a die (9), and a die (9) having an upper end peripheral edge equal to the peripheral edge of a horizontal flange having a predetermined width before turning back. A cylindrical flange holder (10) with a top wall and a vertical bar-shaped container holder (11) that passes through the top wall of the flange holder (10) and can be moved up and down, and around the upper end of the flange holder (11) An annular projecting portion (15) is provided that is closely fitted in the circular hole (13) of the upper die set (12) and is received by the spring (14).

  This edge cutting mold (C) is used as follows. First, place the cup-shaped container (A) on the punch (8) in the opposite direction and place the cup-shaped container (A) in the opposite direction, lower the container holder (11), and punch the bottom of the cup-shaped container (A) from above (8). Hold it so that it does not move. A portion (7a) slightly larger than the predetermined width of the horizontal flange (7) of the cup-shaped container (A) protrudes from the circular edge of the punch (8). Next, both the die (9) and the flange presser (10) are lowered, the horizontal flange (7) is pressed against the punch (8), and the die (9) around the flange presser (10) is further lowered, As a result, a portion (7a) slightly larger than the predetermined width of the horizontal flange (7) protruding from the circular edge of the punch (8) is trimmed to form a horizontal flange (5) having a predetermined width. At this time, the flange presser (10) compresses the spring (14), and the horizontal flange (5) having a predetermined width is held on the punch (8) by the spring force.

  Next, the horizontal flange (5) having a predetermined width is bent vertically using the vertical bending mold (D) shown in FIGS. The vertical bending mold (D) is closely fitted into the die (16) and the die (16) so as to be movable up and down, the lower end is received by the gas spring (17), and the double structure flange (6) A flange presser (18) having an upper peripheral edge equal to the peripheral edge, a cylindrical punch (19) with a top wall, and a vertical bar-shaped container presser (20) that passes through the top wall of the punch (19) and can be vertically adjusted; The outer diameter of the tip of the punch (19) is smaller than the inner diameter of the tip of the die (16) by the thickness of the horizontal flange (5), and the inner diameter of the tip is substantially equal to the outer diameter of the mouth of the cup-shaped container (A).

  This vertical bending mold (D) is used as follows. First, place the cup-shaped container (A) on the flange retainer (18) so that it is centered on the flange retainer (18) in the opposite direction, lower the container retainer (20), and press the bottom of the cup-shaped container (A) from the top with the flange retainer ( Press down so that it does not move to 18). A portion larger than the width of the double-structured flange (6) of the cup-shaped container (A) protrudes from the circular edge of the flange retainer (18) and rests on the upper end surface of the die (16). Next, the punch (19) is lowered, and its tip is pushed into the die (16) by pushing down the flange holder (18) against the spring force of the gas spring (17). The peripheral edge (5a) of the horizontal flange (5) having a predetermined width protruding from the circular edge is first bent vertically.

The peripheral edge (5a) of the vertical bending flange obtained as described above is bent in an inwardly inclined shape using an inwardly inclined bending mold (E) shown in FIGS. The inwardly inclined bending mold (E) includes a punch (20) having an upper end periphery having a diameter substantially equal to the periphery of the double structure flange (6), a cylindrical die (21) with a top wall, and a die (21 ) And a vertical bar-shaped container holder (22) that can be adjusted up and down. The inner peripheral surface of the tip of the cylindrical die (21) has a relatively slanted surface from the bottom to the top. (23) A vertical surface (24) having an inner diameter substantially equal to the diameter of the tip of the punch (19) and a relatively steep inclined surface (25) are formed. As a specific inclination angle, the angle (θ ₁ ) of the gentle inclined surface (23) is selected from a range of 3 to 15 ° with respect to the vertical surface (24), but here it is 10 °. If it is less than 3 °, the peripheral edge (5a) of the vertical bending flange is not smoothly guided to the vertical surface (24), and if it exceeds 15 °, it strikes the inclined surface (23) and this is not smoothly guided. Preferably, it is 7 to 10 °. The angle (θ ₂ ) of the steeply inclined surface (25) is selected from the range of 20 to 60 °, and here it is 45 °. If the angle is less than 20 °, the bending process becomes severe, and the peripheral edge of the vertical bending flange (5a) may be damaged. . Preferably, it is 30-50 degrees. Above the steeply inclined surface (25) is the inner peripheral surface of the die (21) that is equal to the outer peripheral surface of the mouth of the cup-shaped container (A) via the horizontal surface (26) that follows.

  This inwardly inclined bending mold (E) is used as follows. First, place the cup-shaped container (A) on the punch (20) in the opposite direction, place the cup-shaped container (A) in the opposite direction, lower the container holder (22), and punch the bottom of the cup-shaped container (A) from above (20). Hold it so that it does not move. In this case, the outer peripheral surface of the peripheral edge (5a) of the vertical folding flange of the cup-shaped container (A) is substantially on the same vertical surface as the outer peripheral surface of the tip of the punch (20).

  Next, when the punch (22) is lowered and its tip end enters the lowered vertical surface (24) of the die (21), the vertical bent flange peripheral edge (5a) continues on the vertical surface (24). It is squeezed by the steeply inclined surface (25) and bends inwardly along this.

  The inner inclined bent flange peripheral edge (5a) is pressed using a pressing mold (F) shown in FIGS. 11 and 12, and the flange base (5b) forms a double structure flange (6). . The pressing mold (F) includes a punch (27) having an upper peripheral edge larger in diameter than the peripheral edge of the double structure flange (6), a cylindrical die (28) with a top wall, and a top wall of the die (28). It consists of a vertical rod holder (29) that penetrates and can be moved up and down, and the inner peripheral surface of the tip of the cylindrical die (28) has a height (H) that is lower than the vertical height of the double structure flange (6) And a downward stepped portion (30) having a width slightly larger than the peripheral edge of the double-structure flange (6) is formed, and the lower surface of the die (28) during pressurization and the punch (27 ) So that a clearance (S) of 0.2 mm is generated. The total of the gap (S) and the height (H) of the stepped portion (30) is selected from a range of 2 to 5 times the thickness of the composite material (4). The reason is the same as that described for the invention of claim 4.

  This press-molding mold (F) is used as follows. First, place the cup-shaped container (A) on the punch (27) in the opposite direction and place the cup-shaped container (A) in the opposite direction, lower the container presser (29), and punch the bottom of the cup-shaped container (A) from above (27). Hold it so that it does not move. Next, the die (28) is lowered, and the inwardly inclined bent flange peripheral portion (5a) of the cup-shaped container (A) is put into the downward step (30) of the die (28), and this is inserted. When pressure is applied toward the flange base (5b) with the horizontal surface of the downward step (30), a double-structured flange (6) is obtained with the flange base (5b). When this cup-shaped container (A) is taken out from the pressing mold (F), it becomes a cup-shaped container provided with a double-structured flange by the method of the present invention.

It is the top view which notched a part of the tapered cup-shaped container which provided the flange of the double structure. It is the front view which notched a part of container of FIG. It is a principal part expansion detailed longitudinal cross-sectional view of the container of FIG. FIG. 2 is a partially enlarged longitudinal sectional view of the container of FIG. 1 showing a state in which an overcap is hooked and attached to a flange. It is a longitudinal cross-sectional view of an edge cutting die. FIG. 6 is an enlarged vertical cross-sectional view of a main part of the edge cutting die in FIG. 5 showing a state in which the flange has been edge cut. It is a longitudinal cross-sectional view of the vertical bending molding die. FIG. 8 is an enlarged vertical cross-sectional view of a main part of the vertical bending mold shown in FIG. 7 showing a state where the flange is bent vertically. It is a longitudinal cross-sectional view of the inward inclined bending mold. FIG. 10 is an enlarged vertical sectional view of a main part of the inwardly inclined bending mold shown in FIG. 9 showing a state where the flange is bent inwardly. It is a longitudinal cross-sectional view of the press-molding mold. FIG. 12 is an enlarged vertical cross-sectional view of a main part of the press-molding mold of FIG. 11, showing a state where a peripheral edge portion of the inwardly inclined bent flange is pressed toward the flange base portion to form a double-structure flange flange.

Explanation of symbols

(1) Aluminum foil core layer
(2) (3) Synthetic resin coating layer (unstretched polypropylene coating layer)
(4) Composite material (5) Flange (5a) Peripheral edge of flange (5b) Flange base (6) Double-structured flange (A) Tapered cup-shaped container (E) Inwardly inclined bending mold ( 20) Punch (21) Cylindrical die with top wall (22) Vertical bar-shaped container holder (23) Loose inclined surface (24) Vertical surface (25) Steep inclined surface (θ ₁ ) Angle of loose inclined surface (23) ( θ ₂ ) Angle of steep inclined surface (25) (F) Mold for pressurization (27) Punch (28) Die (29) Vertical bar-shaped container holder (30) Downward stepped portion (H) Height of stepped portion ( S) Clearance between the bottom surface of the die and the top surface of the punch during pressurization

Claims (5)

  Using a composite material consisting of an aluminum foil core layer and a synthetic resin coating layer formed on both sides of the whole, a peripheral edge of the flange is vertically bent with the peripheral edge of the flange bent vertically downward in a tapered cup-shaped container. First, the peripheral edge of the vertical bending flange is bent inwardly with an inwardly inclined bending mold, and then the inwardly inclined flange edge is pressed against the horizontal flange base with a pressurizing mold. This is a method of providing a double-structured flange in a cup-shaped container that forms a double-structured flange.   To provide a tapered cup-shaped container with a vertically bent flange peripheral edge where the peripheral edge of the flange is vertically bent downward, first, a taper having a horizontal flange slightly larger than a predetermined width for obtaining a double-structured flange. After forming a cup-shaped container, the peripheral edge of the horizontal flange is cut into a horizontal flange of a predetermined width, and then the peripheral edge of the horizontal flange of the predetermined width is bent downward at a substantially right angle to form a peripheral edge of the vertical bent flange. The method of providing a double-structured flange on the cup-shaped container according to claim 1, which is a part.   It consists of a punch with a top edge that is almost the same diameter as the periphery of the double-structured flange, a cylindrical die with a top wall, and a vertical bar-shaped container holder that can be adjusted up and down, inside the tip of the cylindrical die. An inwardly inclined shape in which a peripheral surface is formed with a relatively gentle inclined surface from the lower end upward, a vertical surface having an inner diameter substantially equal to the diameter of the tip of the punch, and a relatively steep inclined surface Bending mold.   4. The inwardly inclined bending mold according to claim 3, wherein the inclination angle is 3 to 15 degrees when the inclination angle is gentle and 20 to 60 degrees when the inclination angle is steep.   It consists of a punch with an upper edge that is larger than the periphery of the double-structured flange, a cylindrical die with a top wall, and a vertical bar-shaped container holder that can be adjusted up and down, and the inner peripheral surface of the die tip. Are formed with a downward stepped portion, the downward stepped portion having a height lower than the vertical height of the double structure flange and slightly larger than the peripheral edge of the double structure flange, and the bottom surface of the die when pressed and the punch A pressing mold in which a gap is formed between the upper surface and the total height of the gap and the stepped portion is 2 to 5 times the thickness of the composite material.

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