JPH11180432A - Manufacture of plastic box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve form stability of a bottom lid of a plastic box. SOLUTION: The vicinity of a side rim 2b of a body wall sheet piece 2 of a developed sheet and a pasting piece 7 are joined via instantaneous adhesive to prepare a body wall 1 in a folding form, and respective first bottom wall pieces 5 of the developed sheet and a joint 6b of respective second bottom wall pieces 6 overlaid in a two-fold form respectively are joined via hot-melt adhesive H respectively to provide a pair of bottom lids 8 in a folding form which can be folded to stand into a developed form in plane, thereby preparing a flat plastic box B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a plastic box from a developed sheet having a shape obtained by expanding a plastic box used as a package for accommodating various kinds of products and the like in a plane.

[0002]

2. Description of the Related Art A sheet for a body wall, which is formed by punching a plastic sheet such as polypropylene or PET which is difficult to adhere, and in which two pairs of side walls are arranged, and a sheet for the body wall Three upper lid pieces connected to one edge of the body, two pairs of bottom wall pieces connected to the other edge of the body wall sheet piece, and one side edge of the body wall sheet piece. Deployment sheet having a pasted margin piece
Conventionally, when a plastic box is manufactured from a plastic box, a plastic box is manufactured only by a body sticking process of forming a body wall by bonding a marginal piece to the other side edge of the body wall sheet piece with an adhesive. I was

[0003]

In the above-described method for manufacturing a plastic box, the bottom lid of the plastic box is so formed that two bottom wall pieces are alternately overlapped and engaged with each other. Because each bottom wall piece is not joined because it is molded,
The shape of the bottom cover of the plastic box is unstable, the structural strength of the bottom cover is insufficient, and the operation of forming the bottom cover of the plastic box is complicated. An object of the present invention is to improve the form stability of the bottom lid of a plastic box and to simplify the molding operation of the bottom lid of a plastic box.

[0004]

According to a first aspect of the present invention, there is provided a method for manufacturing a plastic box, comprising: a body wall sheet having a pair of first side walls and a pair of second side walls arranged alternately; Three upper lid pieces connected to the edges of the body wall sheet, and a pair of first bottom wall pieces and the two second side wall pieces connected to the edges of the first side wall pieces, respectively. 1 connected to each edge
A deployed sheet having a pair of second bottom wall pieces and a marginal piece connected to one side edge of the body wall sheet piece, and punched and formed into a shape obtained by developing a plastic box. The side wall near the one side of the rebound margin of the trunk wall sheet and the marginal piece are joined by an instant adhesive, and the trunk wall to which the side wall pieces are connected endlessly can be deformed into a rectangular cylindrical shape. Each of the first bottom wall pieces and the respective first
A pair of bottom lids for closing the bottom of the body wall by joining the second bottom wall pieces, each of which is folded in two on the bottom wall piece, with a hot melt adhesive, respectively, to form a pair of bottom lids. It is made in a folded form that can be bent and raised.

According to the first aspect of the present invention, when a plastic box is manufactured from an unfolded sheet, a pair of the first pairs of the first boxes are alternately arranged.
A marginal piece connected to one side edge of the body wall sheet piece having the side wall piece and the pair of second side wall pieces, and a vicinity of one side edge of the body wall sheet piece on the opposite side of the rebound margin are instantaneous. Two pairs of side wall pieces are connected endlessly by bonding with an adhesive,
Create a body wall in a folded form that can be deformed into a rectangular tube shape. Also, a pair of first first members connected to each side wall piece, respectively.
The first bottom wall piece of the bottom wall piece and the pair of second bottom wall pieces, and the second bottom wall pieces each of which is folded in two on each of the first bottom wall pieces, respectively. A pair of bottom lids are formed by joining with a hot melt adhesive to form a folded form that can be bent and raised into a plane developed form. When the body wall is deformed into a rectangular tube shape, both the folded bottom walls are bent and raised into a plane development form, and the bottom of the body wall is closed by the both bottom lids.

According to a second aspect of the present invention, in the first aspect of the present invention, the closure is parallel to the edge of the second side wall piece and the distance from the edge is の of the width of the first side wall piece. A mating portion having an edge and a locking edge connected at right angles to one end of the closing edge; an inclined edge connected to a tip of the locking edge and inclined at an inclination angle of 45 °; The joints of the pair of second bottom wall pieces, each of which is formed with a joint that is bent by a fold inclined at an angle, are respectively joined to the pair of first bottom wall pieces that are respectively superimposed on the joints. To form a pair of bottom lids.

According to the second aspect of the present invention, when the body wall of the flat plastic box is gradually deformed into a rectangular cylindrical shape,
The both bottom lids are gradually bent and raised with the deformation of the trunk wall, the two inclined edges approach while slidingly contacting each other, and the both meshing parts gradually approach the center of the trunk wall. When the torso wall is deformed until its cross-sectional shape becomes substantially square, the two meshing portions are automatically meshed at the center of the torso wall and are hooked to each other, and the two bottom walls are respectively automatically flattened. This is converted into a form, and the flat developed form of the both bottom walls is held by the meshing of both meshing portions.

[0008]

Next, an embodiment of the present invention will be described with reference to the drawings. A development sheet S set up in a cubic plastic box B used as a package for accommodating various articles has a shape obtained by expanding the plastic box B, and is made of polyethylene, PET, polyvinyl chloride, or the like. It is stamped and formed by stamping a plastic sheet.

Each of the unfolded sheets S has a fold 10
a body wall sheet piece having a pair of first side wall pieces 3A and a pair of second side wall pieces 3B alternately arranged in a horizontal row in a state of being connected via a, 10b and 10c; 2 are formed.

Each of the side wall pieces 3A and 3B is formed in a rectangular shape, and the width of each of the first side wall pieces 3A is smaller than the width of each of the second side wall pieces 3B in this embodiment.

A gluing piece 7 is connected to one side edge 2 a of the body wall sheet piece 2 via a fold 11.

When the marginal piece 7 is joined to the vicinity of the side edge 2b on one side of the rebound margin of the body wall sheet piece 2, each side wall piece 3
A body wall 1 in which A and 3B are connected endlessly is formed.

The three upper lid pieces 4 serving as the upper lids of the plastic box B are sandwiched between one end edge of both first side wall pieces 3A of the body wall sheet piece 2 and between the two first side wall pieces 3A. One end edge of the second side wall piece 3B is connected via a fold line 12 respectively.

At the other end edge of both first side wall pieces 3A of the body wall sheet piece 2, trapezoidal first bottom wall pieces 5 which become a part of a bottom lid portion of the plastic box B are respectively provided. The side wall piece 3A is connected via a fold 13 which is an edge.

The pair of first bottom wall pieces 5 have folds 13
In parallel with the above, the top edge 5a whose distance from the fold 13 is 横 of the width of the first side wall piece 3A is inclined at an inclination angle of 45 ° and connects one end of the top edge 5a and one end of the fold 12. A first inclined edge 5b aligned with the line segment and a second inclined edge 5c aligned with a line connecting the other end of the top edge 5a and the other end of the fold 13 are formed.

At the other end edge of both the second side wall pieces 3B of the body wall sheet piece 2, second bottom wall pieces 6 which are a part of the bottom lid portion of the plastic box B are respectively provided on the second side wall pieces 3B. Crease 1 to be the edge
The pair of second bottom wall pieces 6 and the pair of first bottom wall pieces 5 are alternately arranged in the same manner as the arrangement of the first and second side wall pieces 3A and 3B. I have.

An inwardly recessed portion 6a is formed in the center of each of the second bottom wall pieces 6 near the outer edge thereof.
In the center of the closing edge 2, which is parallel to the fold 14 and whose distance from the fold 14 is の of the width of the first side wall piece 2 </ b> A.
An engaging portion 21 having a base 1a and a locking edge 21b connected to the base of the closing edge 21a so as to be orthogonal to the closing edge 21a is formed.

The concave portion 6a has a first inclined edge 22 connected to the tip of the locking edge 21b of the engaging portion 21 and inclined at an inclination angle of 45 °, and a first inclined edge 22 connected to the tip of the closing edge 21a. The first inclined edge 22 and the second inclined edge 23 inclined symmetrically at an inclination angle of ° are formed.

Each of the second bottom wall pieces 6 is inclined at an inclination angle of 45 ° in alignment with a line connecting the tip of the closing edge 21b and one end of the fold 14, and the second bottom wall piece 6 is folded in two. A fold 25 for deforming into a form and a plane development form is formed respectively.

Each of the second bottom wall pieces 6 is disposed outside the fold 25 in a state of being partitioned by the fold 25, and is joined to the first bottom wall piece 5 in a state of being bent by the fold 25. Portions 6b are respectively formed.

In producing the plastic box B from the spread sheet S, first, while the spread sheet S is spread horizontally and transported by a conveyor, a primer liquid for pretreatment is ejected by a spraying device. Is applied to the vicinity of the side edge 2b on one side of the warpage margin of the body wall sheet 2.

Next, after wiping the primer liquid applied to the body sheet 2, the instant adhesive is discharged from the nozzle and the vicinity of the side edge 2 b of the body wall sheet 2 on one side of the warp margin is discharged. Apply.

As shown in FIG. 3, both the first bottom wall piece 5 and the second bottom wall piece 6 of the development sheet S are folded along the folds 13,1.
4 to be folded inward to overlap the first side wall pieces 3A and the second side wall pieces 3B facing the bottom wall pieces 5 and 6, respectively, and furthermore, the joining portion 6b of the second bottom wall pieces 6 Are bent outward by folds 25, respectively.
Each of the second bottom wall pieces 6 is folded by a fold 25 into a folded form.

In this state, the hot melt adhesive is discharged from the nozzle, and the hot melt adhesive H discharged from the nozzle is discharged.
Is applied in a spot shape to each of the joint portions 6b of the folded second bottom wall pieces 6.

Next, as shown in FIG.
The second side wall piece 3B on one side of the nodule is bent inward by the fold 10c and overlapped on the adjacent first side wall piece 3A, and then the first side wall piece 3A on the one side of the no-reach margin is bent inward by the fold 10a to be adjacent. Second side wall piece 3
Overlay on B.

In this state, the marginal piece 7 is superimposed on the marginal piece 7 near the side edge 2b on one side of the warpage margin of the body wall sheet piece 2 to which the instant adhesive has been applied, and the first bottom wall piece 5 and each The joint portions 6b of the second bottom wall piece 6 are overlapped with each other.

In this state, when the developing sheet S is pressurized to apply a squeezing force to the developing sheet S, the margin piece 7 and the side edge 2b on one side of the rebound margin of the body wall sheet piece 2 are removed. Are bonded by an instant adhesive, and each side wall piece 3 of the body wall sheet piece 2 is joined.
The body wall 1 to which the ends A and 3B are connected endlessly is formed in a flat folded shape that can be deformed into a rectangular tube shape.

Simultaneously with the formation of the body wall 1, the first bottom wall pieces 5 and the joining portions 6b of the second bottom walls 6 are respectively joined by the hot melt adhesive H, so that the inside of the body wall 1 in a folded form is formed. The pair of bottom walls 8 sandwiched between the two are formed in a folded form that can be bent and raised into a planar development form, and a flat plastic box B is manufactured.

When the flat plastic box B is pressed and bent by hand and shaped into a box-shaped three-dimensional shape, the body wall 1 of the plastic box B is sandwiched and pressed at the positions of the folds 10a and 10c, and gradually pressed. When deformed into a shape, as shown in FIG. 5, the both bottom lids 8 in the folded form are gradually bent and raised with the deformation of the body wall 1, and the first inclined edges 22 of the both bottom lids 8 come into sliding contact with each other. The two meshing portions 21 gradually approach toward the center of the body wall 1 while approaching.

When the body wall 1 is deformed until its cross-sectional shape becomes substantially square, the both meshing portions 21 of the both bottom lids 8 automatically mesh with each other at the center of the body wall 1 and are locked together. Both closing edges 21
a and the two locking edges 21b are aligned in a straight line and are orthogonal to each other, and the both bottom lids 8 are bent and raised into planar shapes, respectively, and are automatically converted to a planar deployment form.
The two bottom lids 8 are respectively held in a flat developed form by the engagement of the two.

The plastic box B is shaped in such a manner that the body wall 1 is deformed into a rectangular tube shape, and the bottom of the body wall 1 is closed by the two bottom lids 8 in a plane development form.

In the above embodiment, when manufacturing the plastic box B from the spread sheet S, the instant adhesive is applied near the side edge 2b on one side of the rebound margin of the body wall sheet 2 of the spread sheet S. The first and second side wall pieces 3 are applied by bending both first bottom wall pieces 5 and both second bottom wall pieces 6 inward.
A and 3B are superimposed on each other, and the joint portions 6b of the two second bottom wall pieces 6 are bent outward by the folds 25 so that the second bottom wall pieces 6 are folded in two. Hot-melt adhesive H is applied to both joints 6 b of wall piece 6.

Next, the body wall sheet piece 2 is creased 10c,
When sandwiching pressure is applied to the body wall sheet 2 folded and folded at 10a, the side wall 2b of the body wall sheet 2 and the marginal piece 7 are joined by an instantaneous adhesive, and each side wall piece 3
At the same time as the body wall 1 in which the end portions A and 3B are connected endlessly is formed in a folded form, each first bottom wall piece 5 and each second bottom wall piece 5 are formed.
The joining portions 6b of the bottom wall pieces 6 are joined with the hot melt adhesive H, respectively, so that the pair of bottom lids 8 are formed in a folded form that can be developed in a plane.

According to the above-described embodiment, the pair of bottom lids 8 serving as the bottom lids of the plastic box B are formed by joining the first bottom wall piece 5 and the second bottom wall piece 6, respectively. Since it can be bent from the folded form to the flattened form, the structural strength of the bottom lid of the plastic box when the plastic box B is shaped into a three-dimensional shape is enhanced to improve the form stability of the bottom lid. be able to.

Further, by deforming the body wall 1 into a rectangular tube shape, the form of the both bottom lids 8 is automatically changed from the folded form to the flat developed form, and the two meshing portions 21 are automatically meshed. Thus, since the plastic box B can be shaped into a three-dimensional shape, the manual operation of forming the bottom lid of the plastic box can be eliminated, and the shaping operation of the plastic box can be simplified.

[0036]

According to the first aspect of the present invention, the pair of bottom covers serving as the bottom cover of the plastic box are formed by joining the first bottom wall piece and the second bottom wall piece, respectively, and are in a folded form. Since it can be bent to a flat deployment form from above, the structural strength of the bottom lid of the plastic box when the plastic box is shaped into a three-dimensional shape can be strengthened and the form stability of the bottom lid can be improved .

According to the second aspect of the present invention, by deforming the body wall into a rectangular cylindrical shape, the form of the both bottom lids is automatically changed from the folded form to the plane developed form, and the both meshing portions are automatically formed. The plastic box can be formed into a three-dimensional shape because of the meshing state, so that the manual work of forming the bottom lid of the plastic box can be eliminated and the shaping operation of the plastic box can be simplified.

[Brief description of the drawings]

FIG. 1 shows one embodiment of the present invention, and is a perspective view of a plastic box shaped into a three-dimensional shape.

FIG. 2 is a plan view of a development sheet.

FIG. 3 is a plan view of the spread sheet showing a state when an adhesive is applied to the spread sheet.

FIG. 4 is a partially broken plan view of a plastic box showing a state when a trunk wall and a bottom lid are created.

FIG. 5 is a rear view of the plastic box showing a state in which the bottom cover is being converted from the folded state to the planar developed state.

FIG. 6 is a rear view of the plastic box showing a state in which the bottom cover has been converted to a planar development form.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body wall 2 Body wall sheet piece 3A 1st side wall piece 3B 2nd side wall piece 4 Top cover piece 5 1st bottom wall piece 6 2nd bottom wall piece 6a Joining part 7 Glue piece 8 Bottom cover B Plastic box S Development Sheet

Claims (2)

[Claims] 1. A pair of alternating first side wall pieces and 1
A body wall sheet having a pair of second side wall pieces, three upper lid pieces connected to the edges of the body wall sheet;
A pair of first bottom wall pieces connected to the edges of the side wall pieces, a pair of second bottom wall pieces connected to the edges of the second side wall pieces, respectively, and the body wall sheet; And a marginal piece connected to one side edge of the piece, and near a side edge on one side of a warpage margin of the trunk wall sheet of a development sheet stamped and formed into a shape in which a plastic box is developed. And the pasting pieces are joined by an instant adhesive to form a body wall in which each of the side wall pieces is connected endlessly, in a folding form that can be deformed into a rectangular tube shape, and each of the first bottom wall pieces is formed. A pair of bottoms for closing the bottom of the body wall by joining the second bottom wall pieces, each of which is folded in two, to each of the first bottom wall pieces with a hot melt adhesive, respectively. Plastic made by folding the lid into a flat deployment form that can be bent and raised Method of manufacturing. 2. A closing edge which is parallel to an edge of said second side wall piece and whose distance from said edge is の of a lateral width of said first side wall piece, and is connected to one end of said closing edge in an orthogonal manner. A mating portion having a locking edge;
The joints of the pair of second bottom wall pieces, each formed with an inclined edge inclined at an inclination angle of 5 ° and a joint bent by a fold inclined at an inclination angle of 45 °, are connected to both joints. The method for manufacturing a plastic box according to claim 1, wherein the two bottom lids are formed by joining to the pair of first bottom wall pieces respectively superimposed on each other.