JPH04232038A - Manufacture of fusion-welded box - Google Patents

Abstract

PURPOSE:To make favorable continuous manufacturing possible by a method comprising process of feeding thermoplastic resin sheet in continuous form, projected part forming process, slitting process for forming necessary part and unecessary part, process of blanking single plate of the necessary part and box-making process. CONSTITUTION:Projected part shape 4 is formed by swelling sheet S at the portion corresponding to the bottom of a fusion-welded box 1, which is made of thermoplastic resin sheet S in continuous from continuously delivered from a roll 10. Cuts W are made in the sheet S so as to form the fusion-welded box forming necessary part X, on which parts corresponding to its bottom and side walls are formed and with which the unecessary part Y excluding the necessary part X is partially connected. The sheet S, on which the cuts W are made, is blanked so as to separate a blank Z, which forms the fusion- welded box forming necessary part X, from the unnecessary part Y of the sheet S. The side wall parts of the blank Z, which are separated from the unnecessary part Y of the sheet S, are bent upright so as to produce a box by hot-welding the ends of the side walls. Thus, the fusion-welded box 1 can be favorably and continuously manufactured.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a fused box having a desired uneven shape on the bottom due to the bulging of the sheet while continuously running a long sheet of thermoplastic resin.

0002

2. Description of the Related Art There are various types of boxes for storing foodstuffs, etc., but in recent years, fused boxes made of thermoplastic resin materials have been used. This fusion box is a box in which thermoplastic resin plates are appropriately cut, side walls are bent and erected, and the ends of the side walls are heat fused to each other.

By the way, since these fusion boxes have a flat bottom and side surfaces, the contents may move inside or the bottom may be deformed. To prevent this,
It is possible to form steps or protrusions on the bottom by pressing, etc., but if the completed fusion box is pressed,
There was a risk that the box would be deformed or the fused portions of the side walls would peel off.

[0004] On the other hand, in order to prevent the bottom from being deformed, a welding box has been provided with a partition member installed inside the welding box. However, it is necessary to further attach a partition material to the bottom of the completed fused box, which increases the amount of materials and increases the manufacturing cost. Therefore, the applicant has previously formed an uneven part due to the bulge of the sheet by press molding etc. on the part that will become the bottom of the fusion box when assembled in a flat sheet-like unfolded form. We invented and filed an application for a method for manufacturing a fused box by bending and assembling this flat plate (Japanese Patent Laid-Open No. 2-262526).

[0005] The above-mentioned invention forms uneven shapes such as steps, corrugations, protrusions, grooves, etc. due to the bulges of the sheet on the portion corresponding to the bottom of the flat sheet. You can easily form uneven shapes by using
The fused box could be formed efficiently and was suitable.

[0006]

[Problems to be Solved by the Invention] However, in the above manufacturing method, the flat veneers stacked in the stock part are taken out one by one from the stock part using an ejecting device, and unlike the conventional method, the flat veneers are taken out one by one from the stock part. Since this method utilized the same mechanism for manufacturing a fused box from a veneer cut into veneers, it had the following disadvantages. (a) In the case of veneers with uneven parts formed by the swelling of thermoplastic resin sheets, when stacked, the bulges will be smaller than flat veneers with no uneven parts formed on the surface. However, it is bulky, and in the conventional stock space, only a small amount of stock can be stored, and it has to be replenished more frequently than before. In addition, in order to avoid frequent replenishment, it is necessary to take up a large space for the stock section, but due to equipment space, equipment balance, etc., it is not possible to provide a very large stock section. Also, (b)
In the above method of stacking veneers, for example, the bulging convex part of the lower veneer stacked one above the other fits into the bulge recess of the upper veneer due to the weight of the stacked veneers, or gets caught. There were some inconveniences such as being unable to take out the paper smoothly.

[0007] This invention overcomes these conventional difficulties,
It is an object of the present invention to provide a manufacturing method for a fused box having a bulging uneven shape on the bottom, which does not require a stock space for veneers, and which enables continuous production of the fused box.

[0008]

[Means for Solving the Problems] A method for manufacturing a fusion box according to claim 1 to achieve the above object is to fuse a long thermoplastic resin sheet through the following steps while continuously running the sheet. The main point is to manufacture shipping boxes. (A) A feeding process in which a long thermoplastic resin sheet is continuously fed out from the unrolled sheet, (B) A feeding process in which a long thermoplastic resin sheet is fed out continuously, (B) A feeding process in which a long thermoplastic resin sheet is fed out continuously.
Step of forming concave and convex shapes such as steps, corrugations, protrusions, grooves, etc. due to the bulge of the sheet in the part corresponding to the bottom of the fusion box, (C) the part corresponding to the bottom and the side walls; (D) trimming step of cutting the thermoplastic resin sheet so that the main part for forming the fusion box formed with the main part remains partially connected to the surplus part other than the main part; (D) heating the cut part; A thermoplastic resin sheet punching step of punching out a plastic resin sheet and separating the veneer that will become the main part for forming a fusion box from the surplus part of the sheet, (E) Side wall of the veneer separated from the surplus part of the thermoplastic resin sheet A box-making process in which the corresponding portion is bent and raised, and then the side wall edges are heat welded to form a box shape.

[0009]

[Operation] According to the method for manufacturing a fusion box having the above configuration,
While a long thermoplastic resin sheet is continuously running, an uneven shape can be formed by bulging on the part of the thermoplastic resin sheet corresponding to the bottom of the welding box in the uneven part forming process, and the heat is removed in the trimming process. A main part for forming a fusion box, which includes a part corresponding to the bottom of the fusion box and a part corresponding to the side walls, can be formed on the plastic resin sheet. In addition, in the punching process, the veneer that will become the main part for forming the fusion box can be separated from the excess portion of the thermoplastic resin sheet, and in the box-making process, the side wall portion of the veneer is bent and raised, and the side wall end It can be formed into a box shape by heat welding.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples will be explained in detail below with reference to the accompanying drawings showing examples. FIG. 4 shows an example of a fusing box manufactured by the method of the present invention, and the fusing box 1 has side walls 3 of the same height on each side of a rectangular bottom 2. In order to prevent the bottom portion 1 from deforming, the bottom portion 1 is formed with a convex portion 4 made of a thermoplastic resin sheet S such as a foamed polystyrene sheet that bulges inward from the outside of the bottom surface.

The bottom portion 2 and side walls 3 are made of thermoplastic resin plates, and the ends of each side wall 3 are heat-sealed to each other.

[0012] The above-mentioned fusion box 1 is made of (A) as shown below.
) Feeding process of long thermoplastic resin sheet S, (B)
(C) Trimming process of forming the main part for forming the fusion box and surplus part on the thermoplastic resin sheet S; (D) Forming the main part for forming the fusion box from the sheet S. It is manufactured through a process of punching out a veneer, and (E) a box-making process of forming a fused box from the punched veneer.

Each of the above steps (A) to (E) will be explained in detail below with reference to FIGS. 1 to 3. (
A) In the feeding process of the thermoplastic resin sheet,
Reference numeral 10 is a winding, which is a long thermoplastic resin sheet S extruded by an extruder or the like and wound to a desired length. Note that 13 indicates a core tube of the winding 10.

[0014]The thermoplastic resin sheet S unwound from the reel 10 is pierced by clamp needles 12 of the chain conveyor 11 provided near the starting end of the reel 10 at both ends in the longitudinal direction. It is held on a conveyor 11 and conveyed to subsequent steps such as the uneven portion shape forming step (B). In the next uneven portion shape forming step (B), a female mold 20 and a male mold 21 for hot press molding are disposed above and below, sandwiching the sheet S. A fusion box 1 is provided on the surface of the female mold 20 facing the male mold 21 and at the tip of the male mold 21.
Concave and convex portions 22 and 23 are respectively formed to match the shape of the convex portion 4 on the bottom of.

[0015] The long thermoplastic resin sheet S is held at both ends and conveyed by the chain conveyor 11.
is the male and female mold 2 in this uneven part shape forming step (B)
By clamping the molds at 0.0 and 21, a convex portion 4 is formed in a portion corresponding to the bottom portion 2 of the fusion box 1. In the case shown in the figure, two convex portions 4, 4 are formed on the sheet S by one mold clamping.

[0016]Before inserting the sheet S between the female and male molds, a softening step is provided for the sheet S, and in this softening step, the sheet S is softened to a deformable state. Good too. In this case, the male and female press molds may be ordinary ones, rather than a hot press mold with a built-in heater or the like. In addition, this uneven portion shape forming step (B) is as follows:
In addition to press forming using the male and female press molds mentioned above, vacuum forming,
The uneven shape may be formed on the sheet S using a known sheet forming method such as air pressure forming. (C) is a trimming step of the sheet S, and in this step, the sheet S on which the convex portion 4 was formed in the portion corresponding to the bottom of the welding box 1 in the uneven portion shape forming step (B) is further trimmed on the bottom portion 2. A main part X for forming a fusion box is formed, in which a corresponding part and a part corresponding to the side wall 3 are formed.

In the trimming step (C), a pressing mold 30 and a receiving mold 31 are provided above and below, sandwiching the sheet S, and the surface of the pressing mold 30 has a main part X for forming a fused box. A trimming blade 32 is provided to make a cut W in the sheet S in a state where the sheet S is partially connected to the surplus portion Y other than the main portion. Further, on the surface of the receiving mold 31, a pressing mold 30 is provided.
An elastic member 33 made of rubber is attached to receive the trimming blade 32 that penetrates the sheet S by the downward movement of the trimming blade 32 .

When the press die 30 is moved downward toward the receiving die 31 side with the sheet S having the convex portion 4 formed on the bottom portion of the fusing box 1 held therebetween, the surplus portion Y other than the essential portion is removed. The main part X for forming the fusion box can be formed on the sheet S so that the connection remains partially at the cut W. The sheet S on which the main part X for forming a fused box has been formed in this trimming step (C) is further conveyed to the next punching step (D) by a chain conveyor 11.

In the punching step (D), a punching die 40 and a frame die 41 are provided above and below, sandwiching the sheet S therebetween. The tip of the push-cut die 40 is used in the trimming process (C)
The shape is approximately the same as the shape of the main part X for forming the fusion box formed on the sheet S in , or is formed slightly smaller than the main part X.

Further, the frame mold 41 has a hole formed therein for punching out the punching mold 40, which corresponds to the shape of the tip of the punching mold 40 described above.

When the push-cut die 40 is lowered and brought into contact with the main part X of the sheet S for forming a fusion box, and then pushed together with the sheet S into the cut-out hole of the frame die 41, the cut W
The main part X for forming the fused box, which was partially connected to the surplus part Y at The veneer Z, which becomes the main part X, is conveyed by a belt conveyor 42 to the next box-making process (E).

The sheet S consisting of the surplus portion Y punched out from the main portion X for forming the fusion box is crushed into particles Sa by an appropriate crushing mechanism (not shown) as shown in FIG. If it is used as a material for forming the winding 10, the material can be used efficiently and resources can be saved, which is preferable.

[0023] Case making process (E) on belt conveyor 42
The transported veneer Z is subjected to the box-making process (E), in which a V-shaped bending groove is formed by the heating blade 51 at the boundary between the part corresponding to the bottom part 2 and the part corresponding to the side wall 3. A portion corresponding to the side wall is bent to stand up from this bending groove, and the end portion of the side wall is further heat welded to form a box shape. This bag making process (E) is described in the applicant's earlier application (Japanese Patent Application Laid-Open No. 2-25252).
The bag making process is almost the same as No. 6).

[0024] However, in the previous application, a heated blade was used to form a V-shaped bending groove and at the same time remove unnecessary edges at the corners of the veneer, but this invention If so, the corner ears have already been removed from the box-forming main part X as surplus parts Y in the trimming process (C), and only the bending grooves need to be formed with the heating blade 51. This point differs from that of the earlier application.

[0025] Below, regarding this case making process (E),
This will be explained with reference to FIGS. 3(a) to 3(e). The veneer Z conveyed to the box-making process (E) by the belt conveyor 42 is set in the molding die 50. Then, before the heating blade 51 comes into contact with the veneer Z, the first
The set veneer Z is held between the pressing plate 52 and the second pressing plate 53 on the molding die 50 side (see FIG. 3).
a) condition).

In this state, the heating blade 51 is pressed against the veneer Z, and a V-shaped bending groove is formed at the boundary between the bottom part 2 and the side wall 3 (the state shown in FIG. 3(b)). After that, heating blade 5
1 retreats to a predetermined position. Furthermore, the pair of first pressing plates 52 and second pressing plates 53 move downward while holding the veneer Z, so that the veneer Z is pressed against the molding die 5.
0 (state shown in Fig. 3(c)). As a result, the portion corresponding to the side wall 3 of the veneer Z is bent along the inner wall of the molding die 50 using the bending groove as a base line, and is raised up.
The ends of the portions of the veneer Z corresponding to the side walls 3 are crimped together in a molten state to form a box shape. The molded box 1 is the first
The press plate 52 and the second press plate 53 are inserted into the conveyance mold 54 provided below the molding die 50 (see FIG. 3).
d) condition).

Thereafter, the first pressing plate 52 and the second pressing plate 53 release the grip on the box 1 and retreat to their respective predetermined positions. Then, a transport mold 5 into which the box 1 is pushed
4 separates from the molding die 50 and transports the molded box 1 to a predetermined position such as a cooling zone (the state shown in FIG. 3(e)). Next, a specific example will be explained. Width 640mm
A rolled sheet S made of expanded polystyrene resin having a thickness of 3 mm and a length of 200 m was held at both ends by clamp needles 12 of a chain conveyor 11 and was allowed to run continuously. In the uneven part shape forming process (B), the sheet S
155mm in height and 110mm in width on the bottom part of the fusion box
Then, the convex portion 4 having a bulging height of 5 mm is placed in a press die 20,
21, two pieces were formed in the width direction. Furthermore, in the trimming step (C), cuts W are made around each of the convex portions 4, 4 of the sheet S using the trimming blade 32, and the length is 255 mm.
A main part X for forming a fusion box was formed, which was a part corresponding to the bottom part 2 and a part corresponding to the side wall 3, each having a width of 210 mm. Then, in a punching step (D), veneers Z forming the two main parts X were punched out from the sheet S, and conveyed by a belt conveyor 42 to a box-making step (E). After forming a V-shaped bending groove on the veneer Z in the box-making process (E),
When the fused box 1 was manufactured by bending and standing up the portion corresponding to the side wall and thermally welding the end portion of the side wall, it was possible to smoothly and continuously manufacture the fused box. Moreover, according to the above-mentioned unwinding method, compared to the above-mentioned veneer stocking method, there is no need for veneer stocking space, and the apparatus space can be made compact and well-balanced as a whole.

[0028] In the above-mentioned embodiment, after the fusion box 1 is formed, a step of aligning the upper surfaces of the side walls 3 with a cutter or the like may be provided. The shape of the convex portion 4 is not limited to the convex shape shown in the above embodiment, but may also be a convex shape consisting of a large number of protrusions, and a smaller convex portion may be formed in the center of a large convex portion. can. On the other hand, in place of the protrusions, recesses such as grooves may be formed. Furthermore, it can also be provided in a shape such as a waveform that is a combination of both convex portions and concave portions.

Various other design changes can be made without changing the gist of the invention.

[0030]

Effects of the Invention As described above, according to the method of manufacturing a welding box of the present invention, while a long thermoplastic resin sheet is continuously running, the portion corresponding to the bottom of the welding box is caused to bulge out. It is possible to mold shapes such as convex parts, and in the trimming process, the main part for forming the welding box consisting of the bottom and side walls can be formed on the thermoplastic resin sheet separately from the surplus part, and furthermore, in the punching process, this welding box can be formed. The essential parts can be separated from the surplus parts as a veneer, and the veneer consisting of the essential parts can be formed into a box shape in the box-making process.

Therefore, according to the method of manufacturing a fused box of the present invention, there is no need for stock space for veneers, the equipment space can be made compact as a whole in a well-balanced manner, and good continuous production of fused boxes can be achieved. can be done.

[Brief explanation of the drawing]

[Fig. 1] A schematic plan view showing the manufacturing process of a fusion box.

[Figure 2]
A schematic sectional view of the same,

[Fig. 3] A schematic explanatory diagram showing the bag making process,

FIG. 4 is a perspective view showing a manufactured fusion box.

[Explanation of symbols]

S Long thermoplastic resin sheet

Claims (1)

[Claims] 1. A method for manufacturing a fused box, which comprises manufacturing a fused box through the following steps while continuously running a long thermoplastic resin sheet. (A) A feeding process in which a long thermoplastic resin sheet is continuously fed out from the unwound; (B) There are steps and corrugations on the portion of the fed thermoplastic resin sheet that corresponds to the bottom of the welding box. , protrusions, grooves, etc.
a step of forming concave and convex shapes by bulging the sheet;
(C) Cut a cut in the thermoplastic resin sheet so that the main part for forming the fusion box, which has a part corresponding to the bottom and a part corresponding to the side wall, remains partially connected to the surplus part other than the main part. (D) A thermoplastic resin sheet punching process in which the thermoplastic resin sheet with the above-mentioned cuts is punched out and a veneer that will become the main part for forming the fusion box is separated from the excess portion of the sheet, (E) Heat A box-making process in which the side wall portion of the veneer separated from the excess portion of the plastic resin sheet is bent and erected, and then the end portions of the side wall are heat welded to form a box shape.