JP5269947B2 - Packaging box manufacturing method - Google Patents

Description

  The present invention relates to a packaging box that has water tightness, durability, and load resistance and can be easily assembled, and a method for manufacturing the same.

  Conventionally, a plate-like sheet made of a thermoplastic resin such as plastic corrugated cardboard is used, and it is used when packaging or transporting products, and it is assembled by heat-sealing the joining parts of the component parts such as the bottom plate and the side plate. Packaging boxes are known. (For example, see Patent Document 1). As a result, the constituent pieces are heat-sealed and firmly joined and integrated, so that the appearance on the appearance can be improved without using a metal fastener or the like for the joined portion. is there.

JP 2010-285212 A

  However, in the packaging box, the corners do not form a right angle unless the tapered end surfaces of adjacent side plates are brought into contact with each other with certainty. In order to join the corners at a right angle, not only the step of bending the side plate with respect to the bottom plate but also the step of joining the tapered end faces to each other is necessary, and the assembly work may be complicated. Further, since the plate-like sheet is melted by the cross-shaped hot plate, a hot plate having a different size is required in accordance with the size of the developed view in the packaging box, which may lead to an increase in manufacturing cost.

  Therefore, the present invention solves such problems, and is a packaging box having water tightness, durability, and load resistance, particularly improving the accuracy of each corner and easily assembling. It is an object of the present invention to provide a packaging box and a method for manufacturing the same.

In order to solve the above-mentioned problems, the manufacturing method of the packaging box according to the first aspect of the present invention is the bonding piece at a predetermined position from the left and right end portions of one thermoplastic resin plate with the four corners cut off. A first bending step of providing a bent groove by thermal melting at the boundary between the bottom plate and the first side plate, bending the first side plate above the bottom plate, and fusing the first side plate; The left and right end faces and the end face of the joining piece are melted, and the bottom plate and the joining piece are provided with bent grooves by heat melting to form the second side plate and bend upward of the bottom plate. A second bending step in which the end faces of the grooves, the left and right end faces of the first side plate, and the end faces of the joining pieces are fused and joined together.

A method for manufacturing a packaging box according to a second aspect of the present invention is the method for manufacturing a packaging box according to the first aspect , wherein the bent groove has a substantially V-shaped cross section. is there.

In the method for manufacturing a packaging box according to the present invention, a plastic corrugated cardboard piece in which a core material having a honeycomb structure is continuously arranged, a plate-like body made of thermoplastic resin, or a core having directionality and a cross-sectional structure of harmonica. Since the plastic corrugated piece in the form of a blower is used, water tightness, durability and load resistance can be improved. Further, by securing a joining piece at the time of forming the bent groove in the first bending step and forming the bent groove in the second bending step, the corner portion of the packaging box is formed by the second side plate and the joining piece. Can be formed. Thereby, it is not necessary to go through the complicated process of joining the tapered end surfaces of adjacent side plates as in the prior art, and the accuracy of each corner can be improved and the packaging box can be easily assembled.

It is an expansion expanded view of the packaging box in the Example of this invention. It is the perspective view which bent the 1st side plate of the packaging box in the Example of this invention. It is a perspective view of the process of forming the 2nd side board of the packaging box in the Example of this invention. It is a perspective view after the 2nd side board of the packaging box in the Example of this invention was formed. It is a perspective view of the packaging box in the Example of this invention. It is an expansion perspective view of the plastic corrugated cardboard piece used for the Example of this invention.

  Hereinafter, a packaging box according to an embodiment of the present invention will be described with reference to the drawings.

  A packaging box 1 according to an embodiment of the present invention will be described with reference to FIGS. The packaging box 1 is made of a single sheet of thermoplastic resin, and includes a bottom plate 2, a first side plate 3, and a second side plate 4.

  As shown in FIG. 6, a single sheet of thermoplastic resin is a plastic cardboard piece R (trade name: Texel (registered trademark), manufactured by Gifu Plastic Industry Co., Ltd.), which is made of polypropylene resin as a raw material. ). The plastic corrugated piece R has a face plate in which the inner side surface R1 and the outer side surface R2 are parallel, and a core material R3 having a honeycomb structure is continuously arranged in the gap between the face plates.

  As shown in FIG. 1, the development view of the packaging box 1 has a shape in which four corners are cut out into a substantially square shape from a substantially rectangular plate-like body. The developed view is melted by a hot plate to form a groove, and the bottom plate 2, the first side plate 3 and the second side plate 4 are formed by bending the groove.

  First, the 1st bending process which forms the baseplate 2 and the 1st side board 3 from the said expanded view is demonstrated. The bottom plate 2 and the first side plate 3 are formed by forming and dividing the bent groove p by thermally melting the developed view with a hot plate heated to about 170 degrees.

  As shown in FIG. 1, the bent groove p is inwardly of the developed view with respect to a substantially rectangular cutout, and secures a joining piece 4a to be described later at a predetermined position from both left and right ends of the developed view. In this state, it is formed up to the upper and lower ends of the developed view. The bent groove p is formed by being melted by a hot plate having a substantially V-shaped cross section. The bottom plate 2 is formed in the inner direction of the bent groove p in the developed view, and the first side plate 3 is formed in the outer direction of the bent groove p. In this way, the bottom plate 2 and the first side plate 3 are partitioned.

  As shown in FIG. 2, the first side plate 3 is bent upward at a right angle from the bent groove p melted with respect to the bottom plate 2, and both the substantially V-shaped opposing slopes in the bent groove p are formed. Fusing and joining. The first side plate 3 is fixed to the bottom plate 2 at a right angle by the first bending step. At this time, the mutually opposing first side plates 3 can be simultaneously melted by the hot plate and bent at the same time.

  At this time, the end surface of the said location in the expanded view which notched the four corners in the substantially square shape comprises the horizontal joint surface 3a and the vertical joint surface 3b. After the first bending step, the horizontal joint surface 3a is positioned so as to be horizontal with the bottom plate 2. On the other hand, the vertical joint surface 3 b is positioned so as to be perpendicular to the bottom plate 2. Further, the vertical joining surface 3 b forms left and right end surfaces of the first side plate 3.

  Next, a description will be given of a second bending step in which both side portions of the bottom plate 2 that do not have the first side plate 3 are partitioned by bending grooves to form the second side plate 4 and the joining piece 4a. The bottom plate 2 is melted by the hot plate 5 in a state where the first side plate 3 is fixed vertically to the bottom plate 2 in the first bending step.

  The hot plate 5 has a substantially rectangular parallelepiped shape, for example, and includes a groove forming portion 5a, a horizontal surface 5b, and a vertical surface 5c. The groove forming portion 5a is a corner portion located on the lower side, and is formed so as to protrude from the end surface in a substantially V-shaped cross section. Further, the lower end surface of the hot plate 5 forms a horizontal surface 5b, and has a groove forming portion 5a at the corner, and the end surface connected to the horizontal surface 5b forms a vertical surface 5c.

  As shown in FIG. 3, the hot plate 5 heated to about 170 degrees is lowered to melt the bottom plate 2 and the first side plate 3. Specifically, the hot plate 5 is arranged so that the horizontal joining surface 3a of the first side plate 3 and the horizontal surface 5b of the hot plate 5 face each other, and the vertical joining surface 3b of the first side plate 3 and the vertical surface of the hot plate 5 are arranged. It is lowered in a state where it is arranged so as to be in contact with 5c.

  As a result, a bent groove q having a groove slope 3c is formed in the hot plate 5 as shown in FIG. 4, and the second side plate 4 is formed in the outer direction of the bent groove q. In this way, the bottom plate 2 and the second side plate 4 are partitioned.

  The bent groove q is formed from one first side plate 3 to the other opposing first side plate 3, and the cross section forms a substantially V-shaped groove slope 3c. The groove slope 3c is formed on the bottom plate 2 and the horizontal joint surface 3a. Thus, the first side plate 3 and the second side plate 4 are also partitioned at the same time.

  When the bent groove q is formed by the hot plate 5, the horizontal joint surface 3a excluding the groove slope 3c is formed to have the same shape as the vertical joint surface 3b. Thereby, when both are joined, the dimension of the perpendicular direction of the 1st side board 3 and the 2nd side board 4 will correspond.

  The piece that is divided into the first side plate 3 and the second side plate 4 and has the horizontal joining surface 3 a and is bent upward from the second side plate 4 becomes the joining piece 4 a that is joined to the first side plate 3. By forming the joining piece 4a, the corners of the packaging box 1 are formed at the left and right ends of the second side plate 4. The outer shape of the joining piece 4a is formed together with the first side plate 3 by the bent groove p in the first bending step.

  Then, in a state where the bent groove q is melted, the second side plate 4 is bent upward with respect to the bottom plate 2 so as to be perpendicular to the bent groove q and fused. Specifically, as shown in FIG. 5, the substantially inclined V-shaped groove slopes 3c are fused together, and the horizontal joining surface 3a and the vertical joining surface 3b are fused together, and the bottom plate 2 and the first side plate 3, the second side plate 4 is joined. By the second bending step, the second side plate 4 is fixed to the bottom plate 2 at a right angle. At this time, the opposing second side plates 4 can be simultaneously melted by the hot plate 5 and bent at the same time. In this way, the packaging box 1 is assembled by the first bending process and the second bending process.

  As shown in FIG. 5, the packaging box 1 assembled in this way has joining pieces 4 a that are bent toward the first side plate 3 at the left and right ends of the second side plate 4. The joining piece 4a is fused and joined to the left and right end portions of the first side plate 3 via a straight portion and a hypotenuse portion serving as joining end surfaces. The straight portion is formed by fusing and joining the horizontal joining surface 3a and the vertical joining surface 3b. On the other hand, the oblique side portion is formed by fusing and joining the groove inclined surfaces 3c in the bent groove q.

  Since the oblique side portion is formed from the groove slope 3c, it is formed at an angle of approximately 45 degrees from the lower end portion of the corner portion of the packaging box 1 toward the first side plate 3 side. Further, a straight line portion is formed so as to extend in the vertical direction from the upper end portion of the oblique side portion to the upper end surface of the first side plate 3.

As mentioned above, according to the manufacturing method of the packaging box 1 which concerns on the Example of this invention demonstrated, the joining piece 4a is ensured at the time of formation of the bending groove p in a 1st bending process, and it bends in a 2nd bending process. At the time of forming the groove q, the corner of the packaging box 1 can be formed by the second side plate 4 and the joining piece 4a. That is, the corners of the packaging box 1 can be formed during the assembly process. Thereby, it is not necessary to go through the complicated process of joining the tapered end surfaces of adjacent side plates as in the prior art, and the accuracy of each corner is improved, and the packaging box 1 can be easily assembled.

  Moreover, the hot plate 5 used for a 2nd bending process can also be used at the time of formation of the bending groove p in a 1st bending process. Thereby, since the same hot plate can be used in both steps, the manufacturing cost can be reduced. Furthermore, since both the folded groove p and the folded groove q are formed from two linear grooves, a heat plate having a different size is required in accordance with a change in the size of the developed view in the packaging box 1. It will never be.

  In addition, since the plastic corrugated cardboard piece R in which the core material R3 having a honeycomb structure is continuously arranged is employed, water tightness, durability, and load resistance can be improved. Further, the packaging box 1 is not limited to the plastic cardboard piece R having a honeycomb structure. For example, a plate-like body made of low-foamed polypropylene with a foaming ratio of about 1.5 to 4 times, or a non-foamed polypropylene, or a cross-sectional structure made of polypropylene has a directivity to a so-called core in the form of a harmonica blower It is also possible to employ a plastic cardboard piece having That is, in the first bending process and the second bending process, the cross-sectional structure of the plastic plate may be used as long as the joining end faces are reliably welded to each other.

DESCRIPTION OF SYMBOLS 1 Packaging box 2 Bottom plate 3 1st side plate 3a Horizontal joining surface 3b Vertical joining surface 3c Groove slope 4 Second side plate 4a Joining piece 5 Hot plate 5a Groove formation part 5b Horizontal surface 5c Vertical surface R Plastic corrugated piece R1 Inner side surface R2 Outer side surface R3 core material

Claims (2)

Bonding pieces are secured at predetermined positions from the left and right end portions of one thermoplastic resin plate with the four corners cut off, and a bent groove by heat melting is provided at the boundary between the bottom plate and the first side plate, and the first side plate is A first bending step of bending upward and fusing the bottom plate;
The left and right end faces of the first side plate and the end face of the joining piece are melted, and the bottom plate and the joining piece are provided with bent grooves by heat melting to form the second side plate and bend upward of the bottom plate. A second bending step of bending and joining the end faces of the bent grooves, the left and right end faces of the first side plate, and the end faces of the joining pieces;
A method for producing a packaging box comprising: The method for manufacturing a packaging box according to claim 1 , wherein the bent groove has a substantially V-shaped cross section.

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