JPH07115432B2 - Manufacturing method of fusion box - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a method for producing a fusion bonding box formed by fusing a plate material made of a thermoplastic resin sheet, and more specifically,
The present invention relates to a method for manufacturing a fusion bonding box in which a bottom plate is arranged in a raised bottom shape at a position higher than the lower end surface of a side plate.

<Problems to be Solved by Conventional Techniques and Inventions> Conventionally, as a method of manufacturing a fusion bonding box made of a thermoplastic resin sheet, at least two side plates in which a plurality of side plates to be side plates are continuously provided are used. The ends of the plates to be fused to each other and the ends to be fused to the bottom plate are melted using a hot blade, and the side plates are fused around one bottom plate, and at the same time, the side plates are formed. There has been proposed a method of manufacturing a fusion-bonding box in which bottom plates are arranged in a raised bottom shape by fusing each other (Japanese Patent Publication No. 53-30069).
Issue).

However, the above fusion box manufacturing method has the following problems.

(1) Since one bottom plate and two or more side plate plates are required, the number of parts of the plate material is large and the manufacturing process becomes complicated accordingly.

(2) In the fusion-bonding box manufactured by using the above-described manufacturing method, the side plate is simply brought into contact with the bottom plate for fusion, so that it is easy to select the fusion position of the bottom plate with respect to the side plate. However, depending on the state of fusion bonding, the strength of the entire fusion bonding box is insufficient and the stored weight becomes large, which is a particular problem.

The present invention has been made to solve the above problems, and provides a method for manufacturing a fusion bonding box that can be manufactured with a smaller number of parts and a smaller number of manufacturing steps, and that has sufficient strength. With the goal.

<Means for Solving the Problems> In order to solve the above problems, the manufacturing method of the fusion bonding box of the present invention is
Using a plate material made of a thermoplastic resin sheet, a step of forming a portion corresponding to the bottom plate higher than the lower end surface of the outer periphery of the bottom plate by one step, and a left-right asymmetrical V-shaped bent groove in the outer periphery of the bottom plate. A step of melting and forming, and a plurality of side plate-corresponding portions continuously provided in the outer peripheral portion of the bottom plate around the bent groove are bent and erected upward, and fused with the bottom plate at the contact portion with the outer peripheral portion of the bottom plate. The method is characterized by including a step and a step of fusing adjacent end portions of the standing portion corresponding to the side plate.

<Operation> In the method for manufacturing the fusion-bonding box, a portion corresponding to the bottom plate is formed at a position one step higher than the lower end surface of the outer peripheral portion of the bottom plate, and is continuously provided on the outer peripheral portion of the bottom plate. A plurality of side plate equivalent parts are bent and erected upward around a left-right asymmetrical substantially V-shaped bent groove, and are fused to the bottom plate at the contact portion with the outer peripheral portion of the bottom plate, and adjacent side plate equivalent parts. Since the side plates are formed by fusing the ends of each other to each other, the entire fusion-bonding box can be made of a plate material made of one thermoplastic resin sheet.

Further, since the left and right asymmetrical V-shaped bent grooves are fusion-bonded to each other, it is possible to prevent the melting surface from becoming unnecessarily large and to prevent the melting surface from being formed on the inner surface side of the melting box.

<Example> Hereinafter, the present invention will be described in detail with reference to the drawings.

First, as shown in FIGS. 1 (a) and 1 (b), a plate material S made of one thermoplastic resin sheet is thermoformed, and the outer peripheral portion 11 of the bottom plate equivalent portion 1 is raised, whereby the bottom plate 12
Is lifted to a position one step higher than the other parts of the plate material S.

As the thermoforming method, for example, a normal plate material forming method in which the plate material S is heated and softened and then pressure-molded by a mold having a predetermined shape can be applied. According to this molding method, the size (height) of the step between the outer peripheral portion 11 of the bottom plate and the bottom plate 12 and the recess formed on the lower surface of the bottom plate equivalent portion 1 are determined by the size and shape of the mold.
Since the inner dimensions of 13 are determined, there is an advantage that the above dimensions can be arbitrarily changed by appropriately selecting the die to be used. Further, when this method is used, it is possible to obtain a molded product with high dimensional accuracy in each part, so that it is possible to improve the so-called stacking property when stacking.

When using a foamed resin material as the plate material S, the plate material S is secondarily foamed by the heat applied during the molding of the bottom plate 12, and the thickness of the part 1 corresponding to the bottom plate is mainly set to an arbitrary value. Since it can be adjusted, it is possible to reduce the weight of the fusion bonding box and reduce the cost.

As the plate material S to be used for thermoforming, it is possible to use a plate material in which the ears S1 at the corner positions that are unnecessary when forming the fusion-bonding box A are removed in advance, and a plate material in which the ears S1 are not removed is used. You can also

When the plate material S from which the ears S1 have not been removed is used, a mold used for thermoforming is provided with a removing means for removing the ears S1.
Remove the ear S1 at the same time as molding the bottom plate 12, or
The ear portion S1 may be removed in the step of forming the side plate 2 described later.

Next, as shown in FIGS. 2 (a) to 2 (c), the surface of the connecting portion C between the bottom plate corresponding portion 1 and the side plate corresponding portions 21 ... The bent groove V is melted and formed, and both side end portions (side plate end portions) 21a of the side plate-corresponding portions 21 are melted, so that the bent groove V has opposite plate surfaces V1.
While V2 and the side plate end 21a are in a molten state, the parts 2
When 1 ... is erected upward, the side plate-corresponding portions 21 ... and the outer peripheral portion 11 of the bottom plate-corresponding portion 1 are melted at the wall surfaces V1 and V2 of the bent groove V corresponding to the contact portion T. The side plates 2 are attached to each other, and the side plates 2 adjacent to each other are fusion-bonded to each other at the side plate end portions 21a to form the side plate 2. Thus, the fusion box A as shown in FIG. 3 is completed.

In addition, in order to obtain a flat bottom box from a raised bottom fusion box, the flatness and flatness of the bottom part can be obtained by cutting the lower end 2a of the side plate 2 after the side plate 2 is fusion-bonded. The fusion box is improved and has excellent stability and appearance. Further, the upper end portion 2b of the side plate 2 can be cut for the same purpose.

When the lower end portion 2a of the side plate 2 is cut, the connecting portion C between the portion 1 corresponding to the bottom plate and the portion 21 corresponding to the side plate is lost.
As shown in the partially enlarged view of the figure, the side plate-corresponding portion 21 is fused to the bottom plate-corresponding portion 1 with a sufficiently large fusion area at the contact portion T with the outer peripheral portion 11 of the bottom plate. There is no possibility that the strength of the box A will decrease.

In each step of melting the bent groove V and the side plate end portion 21a, and raising the side plate corresponding portion 21 by bending, for example, the following thermal blade 3 and molding die 4 are used in combination.

As shown in FIG. 4, the hot blade 3 is in contact with the upper surface of the plate material S and has a substantially V-shaped bent groove V on the surface of the connecting portion C (see FIGS. 2A and 2B). Square frame part 31 to melt and form
And the side plate-corresponding portion 21 is extended outside the corner frame portion 31.
And the extended portion 32 for melting the side end portion of the.

The sharp tip portion of the rectangular frame portion 31 that melt-molds the substantially V-shaped bent groove V formed in the plate material S is shown in FIG.
As shown in FIG. 5, it is constituted by a side piece side surface 31a forming a groove V2 on the side plate corresponding portion 21 side of the bending groove V and a bottom plate side surface 31b forming a groove V1 on the bottom plate 1 side of the bending groove V. .

The angles A and B forming the tip portions 31a and 31b of the thermal blade 31 are left-right asymmetrical angles when the center line L is distributed.
Normally, the A side (outer peripheral portion of the bottom plate) has a larger angle than the B side (bottom plate side). The bottom plate side angle (B side angle) of the heat blade 31 is 3 to 23 °, and the bottom plate outer peripheral side angle (A side angle) is 50 to 85 °
Is preferable, and 60 to 90 ° is preferable as the entire hot blade 31.
If the tip angle of the hot blade 31 is not within this range, the melting surface is likely to appear on the surface of the fusion box, which is not preferable.

Height of the bottom plate 12 of the plate S (dimension of the bottom plate 12)
When h (see Fig. 2 <b>) is changed, for example, the hot blade angle A can be changed to a larger hot blade angle B, and the hot blade angle can be changed within a range of asymmetric angles. Thus, the size h of the bottom plate height can be dealt with.

The extended portion 32 of the hot blade 3 is also used to remove the ear S1 when the fusion bonding box A is made from the plate material S from which the ear S1 has not been removed.

A cartridge heater for heating is provided inside the blade edge of the thermal blade 3.
33 is buried, and the thermal blade 3 is heated to a predetermined temperature by the cartridge heater 33. As for the heating temperature, in the square frame portion 31, the bending groove V having a predetermined depth is formed on the upper surface of the plate material S.
Is set to a temperature at which the sheet material S can be melted and formed, and the extension portion 32 is set to a temperature at which the plate material S can be melted.

The shape of the rectangular frame portion 31 is set to the same shape as the bottom plate 12 of the fusion bonding box A to be manufactured. Further, a first pressing plate P1 to be described later passes in the vertical direction inside the corner frame portion 31.

As shown in FIG. 5, the molding die 4 is of a fixed type in which a cavity H having a rectangular cross section is formed in the center, and a plate material S is pushed into the cavity H to bend and raise a side plate corresponding portion 21, It is assembled in a box shape. The molding die 4 can freely adjust the size and shape of its cross section according to the size and shape of the box to be molded.

The manufacturing process with the hot blade 3 and the molding die 4 is shown in FIG.
This will be described with reference to (e).

As described above, the plate material S in which the bottom plate corresponding portion 1 is molded into a predetermined shape is set at a predetermined position on the upper surface of the molding die 4 which is set in advance so as to form a box of a predetermined size.

Then, before the hot blade 3 abuts the plate material S, the bottom plate 12 of the bottom plate equivalent portion 1 is held by the first pressing plate P1 on the hot blade 3 side and the second pressing plate P2 on the molding die 4 side. Thus, the plate material S is securely fixed (see FIG. 6 (a)).

Next, the hot blade 3 is pressed against the plate material S, and a substantially V-shaped bent groove V is formed in the plate material S (see FIG. 6 <b>).

Then, while the thermal blade 3 is retracted to a predetermined position, the pair of pressing plates P1 and P2 are moved downward while holding the plate material S, and the plate material S is pushed into the molding die 4 (sixth). Figure (c)
reference). As a result, the side plate-corresponding portion 21 of the plate material S is bent along the inner wall of the molding die 4 with the bending groove V as a base line and rises up, and the side plate-corresponding portion 21 is located outside the bottom plate.
The side plate 2 is formed by being fused to 11, and the side end portions of the side plate corresponding portions 21 are also fused to each other.

Note that the plate material S is a pair of pressing plates P1, P during the above steps.
Since it is securely held by 2, when the hot blade 3 moves backward, the plate material S is lifted up together with the hot blade 3 or moved left and right by the molten resin adhering to the hot blade 3. In addition, when the portion corresponding to the side plate is bent, the positional deviation of the plate material S is restricted, and the fusion box A
Can be accurately molded.

The fusion-bonding box A manufactured in this way is then pressed against the pressing plates P1 and P2.
Is pushed into the conveying die 5 located below the forming die 4 (see FIG. 6 (d)).

After that, the pair of pressing plates P1 and P2 release the holding of the fusion bonding box A and retreat to their respective predetermined positions. And fusion box A
As shown by the arrow in the figure, the transporting die 5 into which is inserted is separated from the forming die 4 downward and is transferred to the cooling step as the next step (see FIG. 6 (e)).

According to the above device, the plate material S is formed by the pair of pressing plates P1 and P2.
Since the sheet is pushed into the molding die 4 while being held, the side plate corresponding portion 21 can be erected while preventing the plate material S from being displaced, thereby improving the accuracy of the box making process.

Moreover, since the hot blade 3 is brought into contact with and separated from the plate material S in the sandwiched state, when the hot blade 3 tries to separate from the plate material S, the plate resin 3 is lifted by the molten resin attached to the hot blade 3. The fusion bonding box A can be manufactured with high accuracy without causing positional displacement.

The fusion-bonding box A molded as described above is entirely formed of a plate material made of a foamed or non-foamed thermoplastic resin sheet such as polypropylene, polystyrene, or polyethylene, and has a rectangular shape as shown in FIG. The bottom plate 12 and the side plate 2 composed of four side plate-corresponding portions 21 ... Which are integrally connected to the outer peripheral portion 11 of the bottom plate through the connecting portion C are provided.

In the side plate 2, the side plate-corresponding portions 21 ... Are erected around the bottom plate 12 and fused with the bottom plate 12 at the contact portion T with the outer peripheral portion 11, and the end portions of the adjacent side plate-corresponding portions 21 are joined together. It is formed by fusing.

The bottom plate 12 is formed by raising the bottom plate outer peripheral portion 11 along the inner wall surface of the side plate 2 so that the bottom plate equivalent portion 1 is formed higher than the outer peripheral portion 11 by this.
Are arranged in an upper bottom shape at a position one step higher than the lower end surface of the side plate 2.

The present invention is not limited to the above embodiments, and various design changes can be made without changing the gist of the invention.

For example, although the bottom plate 1 is formed in a rectangular shape in the embodiment, the bottom plate may be formed in a pentagonal shape or more or in a triangular shape.
A plate material in which one or more or three side pieces are continuously provided is used.

As the plate material, in addition to the above-described foamed or non-foamed resin plate material, a composite plate material in which a film is laminated on the surface of the foamed plate material can be used. A pattern can be formed by printing on a plate material and a film made of non-foamed resin.

Experimental Example Table 1 shows the results of examination of quality in the preferred range of the dimension of the raised bottom plate and the preferred range of the hot blade angle in view of the degree of fusion. In these cases, the expansion ratio is 13.
8. Using a plate material made of a thermoplastic resin sheet with a thickness of 3.8 m / m, the bottom plate is formed one step higher and the dimension h is changed, and then the hot blade temperature is 300 ° C and the angles of the hot blade A side and B side are varied. Instead, a fusion-bonding box was manufactured by the above-described manufacturing method shown in Table 1.

The quality of the manufactured fusion-bonding box is shown in Table 1 by o and x, and the cross-sections of the manufactured fusion-bonding box are shown in FIGS. 7 (a) to (f).

As can be seen from Table 1 and FIG. 7, good melting boxes are formed in Experimental Examples 1 to 3, but Experimental Example 4 is shown in FIG.
As shown in, the shape of the upper bottom is not formed, and the melting surface 81 is exposed on the surface, which is not very suitable. Further, in Experimental Examples 5 and 6, although a melting box having an upper bottom shape can be formed, the inner bottom of the melting box is not flat and the melting surface 81 is exposed, which is not preferable.

Therefore, the hot blade angle shown in claim 2 is preferable in practice.

<Effects of the Invention> As described above, the manufacturing method of the fusion bonding box according to the present invention, among the bottom plate and the plurality of side pieces, which is wholly made of one plate material, the bottom plate is formed into a raised bottom shape of a predetermined shape. It is manufactured by molding and melting a laterally asymmetrical substantially V-shaped bent groove in the outer peripheral portion of the bottom plate to erect the side plate around the bottom plate and fusing the side plate, the bottom plate and the side pieces together. The fusion bonding box can be manufactured with a smaller number of parts and a smaller number of manufacturing steps, and the manufactured fusion bonding box has sufficient strength because the bottom plate and the side plate are integrally formed.

Furthermore, by changing the tip angle of the hot blade, the height of the bottom plate of the upper bottom can be freely changed, and a raised bottom fusion box having various bottom plate heights can be easily obtained.

[Brief description of drawings]

FIGS. 1 (a) and 1 (b) are views showing a state in which a bottom plate is thermoformed as one step of manufacturing a fusion bonding box from a plate material in the present invention, and FIG. 1 (a) is a perspective view thereof and FIG. FIG. 2B is a cross-sectional view thereof, and FIGS. 2A to 2C show melting of a bent groove in a connecting portion between a bottom plate and a side plate corresponding to one step in a method for manufacturing a fusion bonding box according to an embodiment of the present invention. It is a figure which shows the state which formed and melt | dissolved the side edge part of a side-corresponding part, the same figure (a) is the perspective view, the same figure (b) is the sectional view, and the same figure (c) is used. FIG. 3 is an enlarged view of a hot blade, FIG. 3 is a partially cutaway perspective view showing an embodiment of a fusion bonding box of the present invention, and FIG. 4 is for melting formation of a bent groove and melting of a side end corresponding to a side piece. FIG. 5 is a perspective view showing a hot blade used, and FIG. 5 shows a molding die used for erecting portions corresponding to side pieces and fusing adjacent side end portions to each other. FIG. 6 (a) to FIG. 6 (e) are schematic views showing a process of manufacturing the fusion bonding box of the embodiment using the above-mentioned hot blade and molding die, and FIG. 7 is a fusion bonding box of the present invention. FIG. 3 is a cross-sectional view of each fusion bonding box tested by using the manufacturing method of FIG. A: fusion box, S: plate material, V: bent groove, T: abutting part, 1 ... bottom plate equivalent part, 11 ... outer part of bottom plate, 12 ...
… Bottom plate, 2 …… side plate, 21 …… side plate equivalent part, 21a …… side plate side end, 3 …… hot blade

Claims (3)

[Claims] 1. A step of forming a portion corresponding to a bottom plate higher than a lower end surface of an outer peripheral portion of the bottom plate by using a plate material made of a thermoplastic resin sheet, and a left-right asymmetric V-shaped outer peripheral portion of the bottom plate. A step of melting and forming the bent groove, and a plurality of side plate equivalent portions continuously provided on the outer peripheral portion of the bottom plate around the bent groove are bent and erected upward, and at the contact portion with the outer peripheral portion of the bottom plate. A method of manufacturing a fusion bonding box, comprising: a step of fusing with a bottom plate; and a step of fusing adjacent end portions of a standing portion corresponding to a side plate. 2. The V-shaped bent groove is a hot blade having a sharp plate tip angle of 3 ° to 23 ° at the center and a sharp plate tip angle of 50 ° to 85 ° with respect to the side plate. The method for manufacturing a fusion-bonding box according to claim 1, wherein the fusion-bonding box is formed by using. 3. The V-shaped bent groove has a sharp tip angle of 60 ° to
The method for manufacturing a fusion bonding box according to claim 1, wherein the fusion box is formed by using a 90 ° hot blade.