JP2019171649A - Manufacturing method for paper container - Google Patents

Abstract

To provide a manufacturing method for a paper container with a curved surface having a bottom rim, where a wrinkle hardly forms on a surface of the container.SOLUTION: The manufacturing method for the paper container consisting of a barrel member and a bottom member using paper as a main material and having a thermoplastic resin on at least an inner face side of the container comprises: a barrel member forming step in which an upper end part and a lower end part of the barrel member forms the barrel member in an opened inverted truncated cone shape or a cylindrical shape; and a junction part forming step for forming a junction part by bending an outer peripheral edge of the bottom member into a deep dish shape, folding the lower end part of the barrel member inward so as to sandwich the outer peripheral edge of the bottom member, and carrying out heat-bonding. In the manufacturing method for the paper container, a bottom face part of the bottom member is recessed so as to protrude downward beyond the junction part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a paper container. More specifically, it relates to a method for manufacturing a bowl-shaped paper container.

Conventionally, polystyrene cups have been used as cups for instant noodles.
However, the polystyrene cup has a problem that it is vulnerable to impact and is easily damaged during the distribution process. For this reason, recently, paper containers have been widely used.

  The inverted frustoconical shape is generally used as the shape of the paper container, but in recent years, the shape of the paper container is also required to be diversified in accordance with the diversification of food. For example, there are a method for forming a paper container by combining several parts, a method for forming a paper container by pressing one base paper, or a method for forming a paper container by combining these. (For example, refer to Patent Documents 1 and 2).

JP-A-9-95368 JP 2006-341911 A

  By the way, the new subject also arises by using paper containers. Conventionally, polystyrene cups were formed by press molding, and thus were suitable for manufacturing containers with curved surfaces such as bowls and bowls. However, when the base paper is pressed and processed into a bowl or bowl, a new problem arises that wrinkles enter the container surface. Further, there arises a problem that the thread tail cannot be attached to the bowl shape or the bowl shape. Furthermore, the more complicated the shape is, the more complicated the apparatus becomes, resulting in a problem of increased manufacturing costs. Therefore, satisfactory products have not yet been obtained as bowl-shaped or bowl-shaped paper containers.

  The subject of this invention is providing the manufacturing method which reproduces the shape provided with the curved surface like bowl shape or bowl shape with a paper container.

  In order to solve the above-mentioned problems, the present invention is a method for manufacturing a paper container comprising a trunk member and a bottom member made of paper as a main material and provided with a thermoplastic resin at least on the inner surface side of the container. And a barrel member molding step for molding the barrel member into an inverted truncated cone shape or cylinder shape with the lower end portion released, and the outer peripheral edge of the bottom member is bent so as to form a deep dish, and the outer peripheral edge of the bottom member is sandwiched The bottom part of the body member is folded inward, and the joint is formed by thermocompression bonding, and the bottom part of the bottom member is recessed so as to protrude downward beyond the joint. A manufacturing method is provided.

  According to the present invention, a shape having a curved surface such as a bowl or bowl can be reproduced with a paper container. Thereby, a container shape can be diversified.

It is sectional drawing of the paper container manufactured with the manufacturing method concerning this invention. It is a schematic explanatory drawing for demonstrating the formation process of a trunk | drum member and a bottom member among the manufacturing methods in this invention. It is sectional drawing of the paper container which shape | molded the junction part. It is a schematic explanatory drawing for demonstrating a bottom member processing process among the manufacturing methods in this invention.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described with reference to the drawings. Here, FIG. 1 is a cross-sectional view of the paper container 1 manufactured by the manufacturing method according to the present embodiment. 2-4 is schematic explanatory drawing for demonstrating the manufacturing method which concerns on this embodiment. In addition, the same referential mark is attached | subjected to the element which is the same or it corresponds through all the following drawings, The duplicate description may be abbreviate | omitted. In addition, the embodiment described below is merely an example, and does not limit the use of other known techniques.

  The paper container 1 manufactured by the manufacturing method according to the present embodiment is configured by combining separate members including the body member 10 and the bottom member 20. The paper container 1 according to the present embodiment has a substantially inverted truncated cone shape.

FIG. 2 shows a developed base paper constituting the body member 10. As this base paper, a paperboard having a predetermined thickness and basis weight is used. The thickness of the base paper is arbitrarily selected depending on the size of the container used, the contents to be filled, and the like. On the other hand, the basis weight of the base paper is preferably provided with a basis weight of 180 to 350 g / m ^{2 although it} depends on the form of the finished container.

  In this embodiment, polyethylene films are laminated on both sides of the base paper in order to impart water resistance. Note that a molten resin may be used instead of the polyethylene film. Here, the “thermoplastic resin” described in the claims is a concept including a polyethylene film and a molten resin.

  In the present embodiment, the body member 10 made of the base paper having the shape shown in FIG. 2 is wound in a circular shape, and both ends are overlapped with each other to be assembled into an inverted truncated cone shape. At this time, as a diameter of the paper container 1 concerning this embodiment, 135 mm-150 mm are preferable. Moreover, as an angle (henceforth "taper angle") which the reverse frustoconical trunk | drum member 10 and a perpendicular make, about 8 degrees-12 degrees are preferable. If the taper angle is less than 8 °, it does not look like a bowl or bowl. On the other hand, when the taper angle is larger than 12 °, it is difficult to join the outer peripheral edge of the bottom member described later.

  Next, the bottom member 20 for assembling the bottom part of the paper container 1 will be described. Here, the bottom portion refers to the bottom member 20 formed into a predetermined shape. In the present embodiment, as shown in FIG. The bottom member 20 is made of a base paper like the trunk member 10. It is preferable that a ruled line 30 is provided on the outer peripheral portion of the bottom member 20. In the present embodiment, the bottom member 20 is circular, and ruled lines 30 that extend radially along the circumferential direction are provided. In the present embodiment, a plurality of ruled lines 30 having different lengths are configured. By applying a ruled line process to the base paper, wrinkles can be prevented from occurring during the bottom molding. About 100 to 200 ruled lines 30 are preferably arranged radially. If the number of the ruled lines 30 is too small, a large number of wrinkles may be derived at the time of molding, which may reduce the appearance aesthetics. On the other hand, if the number of ruled lines 30 is too large, the physical strength of the base paper may be reduced.

  In the present embodiment, the outer peripheral edge 21 of the bottom member 20 on which three types of ruled lines 30 having different lengths are formed is bent by drawing to form a deep dish shape. At this time, the distance from the bottom surface of the bottom member 20 to the outer peripheral edge 21 (that is, the depth of the deep dish) is preferably 20 mm to 36 mm. If it is less than 20 mm, the bottom surface portion of the bottom member 20 cannot be sufficiently protruded downward in the bottom member processing step described later. On the other hand, if it exceeds 36 mm, molding becomes difficult.

  Next, the lower end portion 11 of the barrel member 10 formed in an inverted frustoconical shape is bent inward, the outer peripheral edge 21 of the bottom member 20 formed in a deep dish shape is sandwiched, and then heated by a heater or the like to be a barrel member. 10 and the bottom member 20 are thermocompression bonded to form the joint 40 (see FIG. 3). Thereby, it can prevent that water and hot water leak from the inside of a container.

  In addition, as another combination method of the trunk member and the bottom member, there is also the following method. For example, the lower end portion of the body member is bent inward, and the outer peripheral edge of the bottom member is bent outward. And the bent part of both is fitted. Then, the fitting part is heated and thermocompression bonded. Although the container can be molded by such a method as well, care should be taken because there is a possibility of causing poor adhesion due to the thickness when trying to heat-weld the mating parts at a time. On the other hand, if it is the method of this invention, since it does not heat-press at a time, it is hard to generate | occur | produce adhesion failure. Moreover, even if there is a certain taper angle of the body member, the body member and the bottom member can be reliably heat-pressed.

  Next, the curled part 50 is formed on the upper end of the body member 10. As a method for forming the curled portion 50, a method similar to a conventionally widely used forming method can be used. Moreover, you may make a curled part square shape as needed. The timing for forming the curled portion 50 is not particularly limited as long as it is after the body member 10 is formed into an inverted truncated cone shape.

  Subsequently, the bottom shape of the bottom member 20 is processed. As a processing method of the bottom portion, the bottom member 20 may be press-molded from the inside of the container so that the bottom portion protrudes beyond the lower end surface formed by the lower end of the trunk portion with a core having a desired shape (see FIG. 4). Thereby, the bottom part which protruded inside the container is reversed, and it can be made into a bowl shape or a bowl shape. The overall height of the container is preferably about 70 mm to 80 mm with respect to the aperture of 135 to 150 mm.

  The distance from the upper end of the joint 40 to the bottom surface of the bottom member 20 is preferably 15 mm to 22 mm. Or it is preferable that the ratio of the distance from the upper end of the junction part 40 in the height of the whole container to the bottom face part of the bottom member 20 is 20 to 30%. On the other hand, the distance from the lower end of the joint 40 to the bottom surface of the bottom member 20 is preferably 7 mm to 14 mm. Or it is preferable that the ratio of the distance from the lower end of the junction part 40 in the height of the whole container to the bottom face part of the bottom member 20 is 10 to 20%. By setting it as such a numerical value range, a container having a diameter of 135 to 150 mm can be brought close to a bowl shape or a bowl shape. In the present embodiment, since the distance from the bottom surface of the bottom member 20 to the outer peripheral edge 21 is 20 mm to 36 mm, the protruding distance can be in the above range. In addition, the frequency | count of pushing the bottom member 20 from the container inner side with a core is not restrict | limited.

  In the present embodiment, when the bottom member 20 is pressed, the joining portion 40 may be press-molded using a mold. By performing press molding on the joint 40, the joint 40 can be inclined. Thereby, roundness can be given to the external appearance shape of the trunk | drum member 10, and it can be brought closer to a bowl shape or a bowl shape. In addition, you may perform the shaping | molding of the bottom member 20 and the press molding of the junction part 40 simultaneously with one metal mold | die.

  As described above, according to the manufacturing method of the present invention, a shape having a curved surface such as a bowl shape or a bowl shape can be reproduced with a paper container. Further, since the overlapping portions of the layers are not heat-pressed at a time, poor adhesion is unlikely to occur. Furthermore, it is possible to diversify shapes that can be reproduced with a paper container.

DESCRIPTION OF SYMBOLS 1 Paper container 10 Body member 11 The lower end part of a body member 20 Bottom member 21 The outer periphery of a bottom member 40 Joining part

Claims (2)

Paper is a main material, and is a method for producing a paper container comprising a barrel member and a bottom member that are provided with a thermoplastic resin at least on the inner surface side of the container,
A barrel member molding step of molding the barrel member into an inverted truncated cone shape or a cylindrical shape in which the upper end portion and the lower end portion of the barrel member are released;
A joint forming step of bending the outer peripheral edge of the bottom member into a deep dish shape, folding the lower end of the body member inward so as to sandwich the outer peripheral edge of the bottom member, and forming the joint by thermocompression bonding; ,
A bottom member processing step in which the bottom portion of the bottom member is recessed so as to protrude downward beyond the joint portion;
A method for producing a paper container.   The method for manufacturing a paper container according to claim 1, wherein in the bottom member processing step, a distance from a lower end of the joint portion to a bottom surface portion of the bottom member is 7 mm to 14 mm.

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