JP6315728B2 - Container and container manufacturing method - Google Patents

Description

  The present invention relates to a container for food and drink and a method for producing the same.

  Conventionally, as a container for food and drink (paper cup), a container having a body part made of sheet-like material and having a side seam part (bonding part) and a bottom part attached to the inside of the body part. One having an open end sealed with a film-like lid is widely used.

  At the opening end of the container, a curl portion (flange portion) directed to the outside of the container is provided. After the container is filled with contents such as beverages, a lid material is heat sealed, for example, in the curl portion. Glued by.

  Patent Document 1 below describes that the curled portion (mouse roll) is formed so that its cross section is circular.

  Patent Document 2 listed below describes that the curl portion (cup rim portion) is pressed from the vertical direction and formed flat.

  In Patent Document 3 below, when the width of the curled portion in the container axial direction is “A”, the width of the curled portion in the radial direction of the container is “B”, and the thickness of the side wall on which the curled portion is formed is “t”, There is described a container that satisfies 2t <A <B, the curl portion is flat in a direction perpendicular to the axial direction of the container body, a ruled line is formed at the outer peripheral end thereof, and has a space that deforms in the axial direction of the container body. ing.

Special table 2008-507458 JP 2004-042987 A Japanese Patent No. 3462411

  However, when the curled portion has a round shape as described in Patent Document 1, since a relatively large step is formed in the side seam portion, the thermoplastic resin that melts during the heat sealing may fill the step. Failure to do so may result in poor sealing of the lid. Also, in this case, the curled portion is deformed in the vertical direction during heat sealing, and as a result, thermoplastic resin burrs are formed on the inner and outer peripheral ends of the curled portion. When drinking, the inner burrs will come into contact with the lips, resulting in poor mouthfeel.

  In addition, when the curled portion has a flattened shape as described in Patent Document 2, when the foreign matter such as the contents remains sealed in the curled portion during the heat sealing, There is a risk that adhesion may be weakened or a seal failure may occur. In this case as well, burrs remain on the inner and outer ends of the curled portion as described above, and the mouthfeel during drinking is also deteriorated.

  Further, when the curled portion has a flat shape having a ruled line on the outer peripheral portion thereof as described in Patent Document 3, at the time of heat sealing, the curled portion has an inner peripheral side having no ruled line rather than the outer peripheral side having the ruled line. As a result of the movement of the molten thermoplastic resin, burrs are formed at the end of the inner periphery rather than the outer periphery when the cover material is peeled off, and the mouthfeel during drinking is also deteriorated.

  In view of the circumstances as described above, an object of the present invention is to provide a container that is excellent in sealing performance of a lid and has a good mouthfeel during drinking.

  In order to achieve the above object, a container according to an embodiment of the present invention has a trunk portion and a bottom portion. The barrel has a side seam portion formed by bonding a paper material coated with a thermoplastic resin on its side surface, and has a curled portion at one end to which a lid member is bonded by heat sealing. It is. The bottom is formed at the other end of the body. The surface of the curled portion to which the lid member is bonded is formed such that a cross section in the radial direction of the trunk portion is formed in an arch shape, and the position where the thickness of the curled portion in the bonding direction of the lid member is maximum is It exists in the outer peripheral side rather than the position which bisects the width | variety of the said curl part in the radial direction of the said trunk | drum.

  With this configuration, the surface to which the lid member is bonded is formed in an arch shape, and the position where the thickness of the curled portion is maximized is on the outer circumferential side, so that the resin accumulates on the inner circumferential side of the curled portion and the lid member. Since no large burrs are formed at the time of peeling, the mouthfeel during drinking can be improved. Here, the “arch shape” indicates that the shape is generally an arch shape (curved surface), and includes a surface partially including a straight line portion, a concave portion, and the like. Moreover, since the step part of a side seam part can be formed flatly because a curl part is arch shape, the sealing performance of a cover material can be improved.

  In the container, when the bonded lid is peeled off, the burrs remaining on the curled portion by the thermoplastic resin are parallel to the outer peripheral surface and the inner peripheral surface of the trunk portion and at the same distance therebetween. You may form in an outer peripheral side rather than a surface.

  Thereby, when the lid member is peeled off, burrs are not formed near the boundary between the inner peripheral surface of the container and the curled portion, so that the burrs do not touch the lips during drinking, and the mouth feel can be improved.

  In the curled portion, the paper material may be fixed by fusion at least at a portion in contact with the outer peripheral surface of the body portion.

  As a result, the curled portion is fixed to the body portion and the shape of the curled portion is maintained, so that the curled portion does not become flatter than necessary when the lid is heat-sealed. Smooth peeling can be realized because it is possible to prevent the occurrence of poor sealing or the occurrence of sealing failure, and the peeling force does not escape due to deformation of the curled portion when the lid member is peeled off.

  The curled portion may be formed of a curved surface, and the thickness of the curled portion may be smaller than the width of the curled portion.

  Thereby, although a curl part is flat shape, the whole is comprised by a curved surface, and it can prevent that the mouthfeel at the time of drinking worsens.

A container manufacturing method according to another embodiment of the present invention is as follows.
Adhering paper material coated with thermoplastic resin to form a cylindrical body having a side seam portion on the side surface,
Forming a bottom at one end of the body,
A curl portion having a substantially circular cross section is formed at the other end of the body portion,
The cross section in the radial direction of the barrel portion of the surface of the curled portion to which the lid member is bonded becomes an arch shape, and the position where the thickness of the curled portion in the bonding direction of the lid portion is maximum is the position of the barrel portion. Heating and compressing the curled portion so as to be on the outer peripheral side of the position that bisects the width of the curled portion in the radial direction.

  In the container manufacturing method, the thermocompression bonding step includes heat-compressing the curled portion having a substantially circular cross section with a first mold having a flat compression surface, and forming the body portion on the surface to be bonded. The curled portion heated and compressed by the first mold may be compressed by the second mold having the arch shape of the compression surface so that the cross section in the radial direction has the arch shape.

  Thereby, the curled portion can be formed such that the surface to be bonded has an arch shape.

  As described above, according to the present invention, it is possible to provide a container that is excellent in the sealing property of the lid and has a good mouthfeel during drinking. However, this effect does not limit the present invention.

It is a figure which shows the front external appearance of the container which concerns on one Embodiment of this invention. It is an expanded sectional view of the curl part in FIG. It is the flowchart which showed from the manufacturing process of the paper cup in one Embodiment of this invention to the filling process of the content. It is the figure which showed the formation process of the curl part in one Embodiment of this invention. It is the figure which showed the heat sealing process of the cover material in one Embodiment of this invention. It is the figure which showed a mode that the burr | flash was formed in the curl part in one Embodiment of this invention compared with the other curl part. It is the figure which showed the cross section of the level | step-difference part of the side seam part in one Embodiment of this invention compared with the other curl part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Appearance of paper cup]
FIG. 1 is a view showing a front appearance of a paper cup as a container according to an embodiment of the present invention. A part of the figure is shown in section.

  As shown in the figure, a paper cup 100 according to the present embodiment has a body 1 and a bottom 2.

  The body 1 is made of a paper material as a raw material, which is coated (laminated) with a thermoplastic resin such as polyethylene, polypropylene, polyester, etc., punched out as a fan-shaped blank, wound around a cylindrical mold, and side ends. They are stacked and bonded together. A side seam portion 4 is formed on the side surface of the body portion 2 from above and below by bonding of the side end portions.

  The bottom 2 is obtained by drawing a circular bottom paper punched from the same paper material as that of the body 1 and bonding it to the inside of the lower end of the body 1 simultaneously with the bonding of the body 1.

  The lower end of the body portion 1 to which the bottom portion 2 is bonded is folded inward and crimped. Further, a curled portion 3 wound outward is formed at the upper end of the trunk portion 1, and the trunk portion 1 is in an open state in the curled portion 3.

  After the curled portion 3 is filled with a content such as a beverage in the paper cup 100, the paper cup 100 is sealed by the lid material being bonded by heat sealing.

  The paper material as a raw material of the trunk | drum 1 and the bottom part 2 is comprised from multiple layers, for example. The paper material may be coated with a synthetic resin layer, a foam layer, a metal layer, an inorganic vapor deposition film, or the like, in addition to the laminate layer made of the thermoplastic resin.

[Curl shape]
FIG. 2 is an enlarged cross-sectional view of the curled portion 3 (Z portion in FIG. 1).

  As shown in the figure, the curled portion 3 has an adhesive surface 31 to which the lid member is bonded, and a folded portion 32 where the trunk portion 1 is folded. Here, the “adhesion surface 31” refers to the surface to which the lid material is adhered (the surface above the horizontal line Hc that bisects the thickness H of the curled portion 3 in the figure). It does not indicate only the surface to be actually bonded, but also includes the surface around the surface to which the lid material is actually bonded.

The curled portion 3 is entirely formed with a curved surface (for example, at least 50%, desirably 90% or more), and the width L of the curled portion 3 is larger than the thickness H thereof. The ranges of H and L are as follows, for example.
0.5mm ≦ H ≦ 10.0mm
2.0mm ≦ L ≦ 10.0mm

  The adhesive surface 31 is formed in an arch shape in the radial direction of the body portion 1. Here, the “arch shape” indicates a generally arched shape (curved surface), and a straight portion, a convex portion, a concave portion, or the like may be partly provided.

  In other words, the curled portion 3 has a ratio of the width L to the thickness H of the width-thickness ratio in the conventional curled portion having a circular cross section and the width-thickness ratio in the curled portion where the flange is pressed. It is formed to be between.

  Accordingly, the curled portion 3 of the present embodiment has both the advantages of the circular cross-section curl portion and the advantages of the flange-pressed curled portion.

  That is, in the curled portion 3, the adhesive surface 31 is a curved surface, like the curled portion having a circular cross section, so that the contents (such as beverages) filled in the paper cup 100 are adhered to the adhesive surface 31 when the lid member is heat sealed. If the lid member is pressed from above by a seal head, which will be described later, the impurities are pushed out along the shape of the curled portion 3 toward the inner and outer peripheral sides of the curled portion 3. As a result, almost no contaminants are present on the bonding surface, so that a seal failure is unlikely to occur.

  Further, in the curled portion 3, the step formed at the upper end of the side seam portion 4 becomes small like the flange-pressed curled portion. Therefore, the step is flatly filled with the thermoplastic resin when the lid member is heat-sealed. By doing so, a seal failure in the side seam portion 4 can be prevented.

  Further, the curled portion 3 has a certain thickness H like the curled portion having a circular cross section, so that the mouthfeel during drinking can be kept good.

  Further, the position Hm at which the thickness H of the curled portion 3 in the bonding direction (vertical direction in the figure) of the lid member is maximized is a position that bisects the width L of the curled portion 3 in the radial direction of the body portion 1. It is on the outer peripheral side (right side of the figure) from Lc. Here, the position of the end portion on the inner peripheral side (left side in the figure) of the width L of the curled portion 3 is a point X where the horizontal line Hc that bisects the thickness H of the curled portion 3 and the inner peripheral surface of the trunk portion 1 intersect. Yes.

  In other words, in the cross-sectional view of FIG. 2, the curvature of the outer peripheral side 31a (right side of the figure) of the bonding surface 31 is formed to be larger than the curvature of the inner peripheral side 31b (left side of the figure).

  As will be described later, this causes the molten thermoplastic resin to remain on the outer peripheral side 31a rather than the inner peripheral side 31b when the lid member is heat sealed to the adhesive surface 31. Thereby, when the lid member is peeled off, the burr formed on the inner peripheral side 31b is reduced, and the mouthfeel during drinking can be kept good.

  Further, the folded portion 32 of the curled portion 3 is fixed to the barrel portion 1 by fusion at least at a portion P in contact with the outer peripheral surface of the barrel portion 1. In the folded portion 32, for example, surfaces other than the portion P facing the adhesive surface 31 may be fused.

  Thereby, the curl part 3 is fixed to the trunk | drum 1, and the shape of the curl part 3 is maintained. Therefore, when the lid member is heat sealed, the curled portion 3 is not flattened more than necessary, and therefore the content adheres to the curled portion 3 as impurities when the paper cup 100 is filled with the content (such as beverage). However, it is possible to prevent the adhesive force from being weakened or a seal failure from occurring. In addition, when the lid member is peeled off, the peeling force becomes difficult to escape in the direction other than the peeling direction due to the deformation of the curled portion 3, so that smooth peeling can be realized.

[Paper cup manufacturing method]
Next, a method for manufacturing the paper cup 100 will be described. FIG. 3 is a flowchart showing the flow of the manufacturing process of the paper cup 100.

  As shown in the figure, first, a fan-shaped blank is punched out from the paper material laminated with the thermoplastic resin, and both ends thereof are wound around a cylindrical mold in a state of being melted by a gas burner or the like. The body 1 is formed by bonding (step 41).

  In addition, a circular bottom sheet punched out from the same paper material as described above is drawn and vacuum-adsorbed to the cylindrical mold, and the body portion is simultaneously bonded to the ends of the body portion 1. 1 is bonded to the inside of the lower end. And the bottom part 2 is joined to the trunk | drum 1 by the lower end of the trunk | drum 1 being folded in and crimped | bonded to the bottom part 2 side (step 42).

  Subsequently, a curling portion having a circular cross-section in the radial direction of the body portion 1 is formed by curling processing so that the upper end of the body portion 1 is wound outward while being rotated by a tool (step 43).

  Subsequently, the curled portion having a circular cross section is formed so that the adhesive surface 31 has an arch shape as shown in FIG. 2 (step 44). As a result, the paper cup 100 having an open top is manufactured.

  Then, the paper cup 100 is filled with contents such as beverages, and the lid is adhered to the opening (adhesion surface 31 of the curled portion 3) by heat sealing, whereby the paper cup 100 is sealed (step 45). ).

(Forming method of curled part)
Next, details of the molding method of the curled portion 3 will be described. FIG. 4 is a view showing a molding process of the curled portion 3.

  As shown in FIG. 3A, first, the curled portion 3 having a circular cross section formed in step 43 of FIG. 3 is compressed while being heated between the mold 47 and the receiving mold 46. A compression surface 47a for compressing the adhesive surface 31 is formed in a flat shape (perpendicular to the compression direction) in the ring-shaped recess of the mold 47 in which the curled portion 3 is accommodated.

  The heating is performed by using, for example, an ultrasonic horn as the mold 47, but the curled portion 3 may be preheated by hot air, a hot plate, high frequency, or the like.

  When the curled portion 3 is compressed by the mold 47, the curled portion 3 is formed into an elliptical cross section as shown in FIG. B, and the thermoplastic resin in the folded portion 32 is melted.

  Subsequently, as shown in FIG. B, the curled portion 3 having the elliptical cross section is heated and compressed between a mold 48 and a receiving mold 46 different from the mold 47. The ultrasonic horn can be used as the mold 48 as well. In the ring-shaped recess of the mold 48 in which the curled portion 3 is accommodated, the compression surface 48a for compressing the adhesive surface 31 is arched and the outer peripheral side (right side in the figure) is the inner peripheral side (left side in the figure). ) To be larger than the curvature. That is, the compression surface 48a has a shape along the shape of the adhesion surface 31 of the curled portion 3 shown in FIG.

  When the curled portion 3 is compressed by the mold 48, the curled portion 3 has an arched cross section in the radial direction of the body portion 1 as shown in FIGS. The position Hm at which the thickness H of the curled portion 3 is maximized is formed on the outer peripheral side of the position Lc that bisects the width L of the curled portion 3.

  Then, as shown in FIG. 3C, the molded curled portion 3 is cooled by being brought into contact with the cooling surface 49a of the cooling mold 49 and the receiving mold 46, and is stabilized in the molded shape. .

(Paper cup sealing method)
Next, the details of the method for sealing (heat sealing) the paper cup 100 will be described. FIG. 5 is a view showing a sealing process of the paper cup 100.

  As shown in FIG. 1A, first, the filling L 51 fills the paper cup 100 with a content L such as a beverage.

  Next, as shown in FIG. B, the cover material 52 is pressed by the heated seal head 53 in a state where the cover material 52 is placed on the curled portion 3, whereby the adhesion surface 31 of the curled portion 3. The resin is melted and fused to the lid member 52.

  Then, as shown in FIG. 3C, when the cooling plate 54 is pressed against the lid member 52, the molten resin is cooled and the sealing process is completed.

[Burr formation position]
Next, burrs (resin build-up) formed when the lid member 52 is peeled after the paper cup 100 is sealed will be described. FIG. 6 is a view showing a state in which burrs are formed in the curled portion 3 of the present embodiment in comparison with other curled portions.

  FIG. 7A shows a state where the lid member 52 is peeled off from the curled portion 3 of the present embodiment, and FIG. 7B shows a state where the lid member is peeled off from the conventional curled portion having a circular cross section. FIG. C shows a state in which the lid member is peeled off from the curled portion subjected to conventional flange pressing.

  As shown in FIG. A, in the curled portion 3 according to the present embodiment, when the fused lid member 52 is peeled off, the burrs remaining on the curled portion 3 by the thermoplastic resin are bonded surfaces. 31 are formed on the outer peripheral side (burr 61) and the inner peripheral side (burr 62), respectively, but the inner peripheral side burr 62 is much smaller than the outer peripheral side burr 61.

  Specifically, the burr 62 has such a size that the vertical height of the contact surface 31 is about 80 μm. In general, the allowable range of the size with respect to mouthfeel is that the height is about 120 μm or less, preferably 80 μm or less. Moreover, since the burr 61 formed on the outer peripheral side of the cup part 3 hardly touches the lips when drinking, there is almost no influence on the mouthfeel.

  And the position where the said burr | flash 62 is formed exists in the outer peripheral side rather than the intermediate surface C1 which is parallel to the outer peripheral surface and inner peripheral surface of the trunk | drum 1, and the same distance.

  On the other hand, as shown in FIGS. B and C, the burrs 64 and 66 formed on the inner peripheral side in the curled portion having a circular cross section and the flange-pressed curled portion are both inner peripheral sides than the intermediate surfaces C2 and C3. (The left side of the figure) and the heights are 137 μm and 160 μm, respectively.

  As described above, in this embodiment, the burr 62 is formed near the boundary between the inner peripheral surface of the paper cup 100 (the barrel portion 1) and the curled portion 3 when the lid member 52 is peeled, as compared with the conventional curled portion. Therefore, there is no discomfort due to the burr 62 touching the lips during drinking, and the mouthfeel can be improved.

[Flatening the step in the side seam]
Next, the step at the upper end of the side seam portion 4 will be described. FIG. 7 is a view showing a cross section of the stepped portion of the side seam portion 4 of the curled portion 3 in this embodiment in comparison with other curled portions.

  FIG. 3A shows the step portion of the side seam portion 4 of the curl portion 3 of the present embodiment, and FIG. 3B shows the step portion of the side seam portion of the conventional curl portion having a circular cross section. Shows a step portion of a side seam portion of a curled portion subjected to conventional flange pressing.

  As shown in FIG. A, the stepped portion S of the side seam portion 4 of the present embodiment is sufficiently filled with the thermoplastic resin R in the molding step of the curled portion 3 shown in FIG. It is flattened in the same manner as the curled portion subjected to flange press processing shown in C.

  On the other hand, as shown in Fig. B, the stepped portion of the side seam portion of the curled portion having a circular cross section is not sufficiently filled with the thermoplastic resin, and the step remains.

  As described above, in the curled portion 3 of the present embodiment, the thermoplastic resin that melts when the lid member 52 is heat-sealed fills the level difference of the side seam portion 4 to improve the sealing performance of the lid member 52. be able to.

[Summary]
As described above, according to the present embodiment, since the adhesive surface 31 of the lid member 52 in the curled portion 3 is formed in an arch shape, the sealing performance of the lid member 52 can be improved. Further, since the position where the thickness of the curled portion 3 is maximized is on the outer peripheral side, a large burr is not formed on the inner peripheral side when the lid member 52 is peeled off, so that the mouthfeel during drinking can be improved. it can.
[Modification]

  The present technology is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present technology.

  The shape of the curled portion 3 is not limited to that shown in FIG. That is, the surface (adhesion surface 31) on the curled portion 3 on which the lid member 52 is adhered is formed such that the cross section in the radial direction of the body portion 1 is arched, and the curled portion 3 As long as the position Hm at which the thickness of the lid member 52 in the bonding direction is maximum is located on the outer peripheral side of the position Lc that bisects the width of the curled portion 3 in the radial direction of the body portion 1, The curled portion 3 is also included in the present invention.

  Further, the “arch shape” does not indicate that the adhesive surface 31 is entirely formed of a curved surface, but includes a case where a part is formed of a flat surface or a concave surface.

  In the above embodiment, as described with reference to FIG. 4, the curled portion 3 is formed by three processes using three different molds 47, 48, and 49. However, the molding process of the curled portion 3 is not limited to this, and the curled portion 3 can be molded as long as there is at least one compression process using a mold having an arcuate compression surface, such as the mold 48 described above. .

  In the above-described embodiment, the paper cup 100 is manufactured by manufacturing the body 1 and the bottom 2 as different parts and bonding the bottom 2 to the body 1. However, a container such as a paper cup may be manufactured by integrally forming the body portion and the bottom portion from a single sheet of paper, and in this case as well, the curled portion can be formed in the same manner as in the above-described embodiment.

DESCRIPTION OF SYMBOLS 1 ... Body part 2 ... Bottom part 3 ... Curl part 4 ... Side seam part 31 ... Adhesion surface 32 ... Folding part 47, 48, 49 ... Mold 100 ... Paper cup S ... Step part R ... Thermoplastic resin

Claims (5)

A cylindrical body having a side seam portion formed by bonding a paper material coated with a thermoplastic resin on the side surface, and a curled portion at one end of which a lid material is bonded by heat sealing;
Comprising a bottom formed at the other end of the body,
A straight line that bisects the thickness of the curled portion in the crimping direction of the lid member at the position of the inner circumferential side of the width of the curled portion in the radial direction of the barrel portion and the inner circumferential surface of the barrel portion intersect. If it is a point,
Surface where the lid member is adhered in the curled portion is cross section in the radial direction of the body portion is formed in an arch shape, a position where the thickness of the curled portion is maximized, the width of the curled portion Ri outer peripheral side near the position where the bisecting,
When the bonded lid is peeled off, the burr remaining on the curled portion due to the thermoplastic resin is more peripheral than the intermediate surface parallel to and at the same distance from the outer peripheral surface and inner peripheral surface of the barrel portion. A container formed on the side . The container according to claim 1,
In the curl portion, the paper material is fixed by fusion at least at a portion in contact with the outer peripheral surface of the barrel portion. The container according to claim 1,
The curled part is formed of a curved surface, and the thickness of the curled part is smaller than the width of the curled part. Adhering paper material coated with thermoplastic resin to form a cylindrical body having a side seam portion on the side surface,
Forming a bottom at one end of the barrel,
A curl portion having a substantially circular cross section is formed at the other end of the body portion,
A straight line that bisects the thickness of the curled portion in the crimping direction of the lid member at the position of the inner circumferential side of the width of the curled portion in the radial direction of the barrel portion and the inner circumferential surface of the barrel portion intersect. If it is a point,
Section becomes arcuate in the radial direction of the torso portion of the surface on the side where the cover member is bonded in the curled portion, the thickness of the curled portion is maximum position is the position that bisects the width of the curled portion And the burrs remaining on the curled portion by the thermoplastic resin when the bonded lid member is peeled off are parallel to the outer peripheral surface and the inner peripheral surface of the trunk portion. A container manufacturing method in which the curled portion is heated and compressed so as to be formed on the outer peripheral side of the intermediate surface at the same distance . The container manufacturing method according to claim 4 ,
The step of heating and compressing includes a curled portion having a substantially circular cross section, and a compression surface having an arch shape so that the cross section in the radial direction of the body portion of the surface to be bonded becomes the arch shape. The container manufacturing method to compress in.