JPS6238905Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a folding box made of synthetic resin, and more specifically, to a folding box that is watertight and sanitary and has a strong joint between the peripheral side wall and the bottom plate forming the folding box.

Conventional synthetic resin folding boxes are manufactured using the so-called welding method, in which the unfolded box material is assembled using thermoplastic resin foam boards and heat-sealed at important points, resulting in a lot of unused leftover material. The price is high because it generates In addition, since the peripheral side wall connected to the bottom plate is assembled by bending, the approximately linear wood grain pattern on the box material surface of the square folding box can be seen on the vertical and horizontal sides of the peripheral side wall. There were also drawbacks such as defects that appeared in different directions at right angles, discoloration of the fused portion on the inside of the box due to heat melting, and swelling of the resin, which were issues in terms of appearance. Furthermore, in the case of a folding box obtained by cutting and assembling a series of frames from a foam board of a predetermined size, a groove for inserting the bottom plate is cut slightly upward from the bottom edge. and a bottom plate is fitted into the groove to surround the frame material,
The edges of the frame were glued, nailed, or heat welded. However, when glued or nailed, the use of adhesives for food containers and the rust caused by metal nails are not desirable from a food hygiene point of view, and the current situation is that we have no choice but to rely on heat welding. The above-mentioned conventional products, which only involve fitting the bottom plate, have problems such as intrusion of dust and lack of watertightness.

Furthermore, in the case of the joining method by heat fusion, the entire joint surface of the circumferential side wall and the bottom plate is heated and melted in advance, and then the circumferential side wall and the bottom plate are brought into close contact with each other and assembled and joined. Unless the two-step process of production and assembly is carried out quickly and continuously,
The melted area cools and solidifies, making it impossible to join. Furthermore, during assembly, it is necessary to position accurately and quickly to bring the peripheral side wall and the bottom plate into contact, which tends to cause misalignment and poor connection. Therefore, there were disadvantages in that the joining work was difficult and the accuracy of the finish was poor.

Therefore, in this invention, all the drawbacks of the conventional products mentioned above are solved, the peripheral side wall and the bottom plate are joined by heat fusion, and the fusion joining work is easy.
The finish is accurate and strong, making it possible to provide a folding box that is watertight and hygienic as a container.The structure is such that it is bent into a frame shape from the folding groove and then butted. A frame-shaped peripheral side wall made of a thermoplastic foam resin side material whose ends are heat-sealed to each other is formed with a bottom groove whose lower end is open to the outside, and is further separated from the peripheral side wall. The bottom plate made of thermoplastic foamed resin is joined to the bottom plate by a heat-sealed portion formed on the outer surface along the boundary line around the bottom.

Next, embodiments of this invention will be illustrated below with reference to the drawings.

First, in FIGS. 1 to 4, reference numeral 10 denotes a circumferential side wall, which is formed from a thermoplastic foamed synthetic resin plate, such as a foamed polystyrene resin plate (including sheet-like cases), and the circumferential side wall 10 is V-shaped. It is bent into a frame shape using the bending grooves 11... and the abutted ends 13, 13' are heat-sealed 30 to each other to form the frame of the folding box as shown in Fig. 1. There is.

Reference numeral 20 denotes a bottom plate formed from a thermoplastic synthetic resin plate, for example, a foamed polystyrene resin plate (including sheet-like cases), separately from the circumferential side wall 10. (see Fig. 2), and the peripheral side wall 10 and the bottom plate 20 are heat-sealed 40 to each other around the bottom to form a folding box (see Figs. 3 and 4). The symbols c and c' in the figure indicate heat-sealing tools.

To explain in detail the joining of the circumferential side wall 10 and the bottom plate 20 by heat fusion, first, the bottom plate 20 is fitted into the bottom groove 12 of the circumferential side wall 10, and assembled into the final folded box.

Then, the peripheral side wall 10 and the bottom plate 20 in the above-mentioned assembled state
Heat sealing tools c and c' are pressed against the outer surfaces of the two along the boundary line around the bottom of the two. Then, the peripheral side wall 10 and the bottom plate 20 are heated and melted over a certain width on both sides of the boundary line.

Next, when the heat-sealing tools c and c' are removed, the melted portions are cooled and solidified, and the peripheral wall 10 and the bottom plate 20 are fused and integrated at the heat-sealed portion 40 formed along the boundary line. and are joined together.

In addition, the bottom groove is a double groove 12 as shown in FIG.
12' and a bottom plate 20 having a cross-sectional shape that can be fitted thereto, together with the heat-sealed portion 40, can provide a folding box that can sufficiently withstand even when a considerable amount of weight is stored.

Furthermore, the shape of the heat-sealing portion 40 around the bottom can be formed into various shapes depending on the shape of the heat-sealing tools c and c', an example of which is shown in FIG.

Further, linear wood grain patterns b and b' are formed on the outer surfaces of the peripheral side wall 10 and the bottom plate 20,
In particular, in the case of this invention, the pattern b can be formed on the circumferential wall 10 in the same direction both vertically and horizontally.

Moreover, FIGS. 7 to 9 show the order of forming the peripheral side wall 10 of the folding box of this invention,
A is a material for forming the frame-shaped peripheral side wall 10 serving as the side material, and is a thermoplastic synthetic resin plate such as a foamed polystyrene resin plate (including a sheet-like case).
It is formed from a V-shaped groove 1 for bending.
1... in which a bottom groove 12 that can be opened to the outside is formed on the bottom side are sequentially cut into individual circumferential side walls 10 for use.

In addition, although a rectangular folding box is illustrated as an example, polygonal folding boxes having other shapes can also be provided with a similar structure. In addition to polystyrene foam plates, other thermoplastic foam resin plates may be used for the peripheral side wall 10 and the bottom plate 20.

As described above, in the folding box of this invention, the circumferential side wall and the bottom material are made of thermoplastic foam resin that can be easily heat-sealed at the joints, and the circumferential side wall 10 is shaped like a frame from the folding groove 11. Since the abutted ends 13 and 13' are formed by heat-sealing 30 to each other, even if the outer surface has a wood grain pattern b, b', the pattern is side wall 1
0 can be aligned in the same direction as a whole, and it is possible to eliminate the unsightly appearance in which the pattern directions differ in the vertical and horizontal directions of the circumferential side wall, like folded boxes obtained by conventional welding methods.
Furthermore, a bottom groove 12 is formed at the bottom of the circumferential wall 10 with its lower end open to the outside, into which the bottom plate 20 is fitted and bonded together by heat sealing 40 around the bottom. No adhesives or nails are used, making the folding box suitable from a food hygiene perspective.

In particular, the above-mentioned heat fusion bonding is performed beforehand on the bottom plate 20.
are fitted into the bottom groove 12 of the circumferential side wall 10, and are joined to each other by a heat-sealed portion 40 formed on the outer surface along the boundary line between the two around the bottom. After accurately positioning the side wall 10 and the bottom plate 20, the fusion bonding work can be carried out with plenty of time, which not only makes the work easy, but also ensures a strong and accurate finish, and prevents the bonding strength from being weakened due to poor fusion. There is no risk of shortage or deterioration of watertightness.
Furthermore, since the thermally fused portion 40 is exposed on the outer surface, it is easy to inspect the bonded state, and even if a defective fusion occurs due to a work error, it is easy to find the defective location. be.

In addition, since the heat-sealed portion 40 is not exposed on the inner surface of the folding box, resin parts that have changed color or quality due to heating are exposed on the entire inner surface of the folding box, which may impair the appearance or cause food hygiene. The above problem will no longer occur.

Because of the bonding by the heat-sealing portion 40 as described above, the folding box has a securely bonded circumferential wall and bottom plate that form the folding box, and is watertight, preventing moisture from leaking from the bottom of the stored contents. It can demonstrate excellent practical effects such as:

[Brief explanation of the drawing]

The figures illustrate the embodiment of this invention, and Fig. 1 is a perspective view from the bottom side before the bottom plate is inserted, Fig. 2 is a partially cutaway perspective view showing the area around the bottom before heat sealing, and Fig. The figure is a perspective view of the folding box, FIG. 4 is a sectional view of the same as above, FIGS. 5 and 6 are sectional views of modified examples, and FIG.
The figure is a plan view of the material forming the peripheral side wall, and FIGS. 8 and 9 are a side view and a front view of the same. 10... Circumferential wall, 11... Bending groove, 12...
...Bottom groove, 13, 13'...Butt end, 20
...Bottom plate, 30...Heat-sealed portion of butt end,
40, 40'...Heat-sealed part around the bottom, b,
b'...Wood grain pattern.

Claims (1)

[Claims for Utility Model Registration] 1. A frame-shaped periphery made of a side material made of thermoplastic foam resin, which is bent into a frame shape from the bending groove part and whose abutted ends are heat-sealed to each other. On the side wall,
A bottom groove with a lower end open to the outside is formed at the bottom, and a bottom plate made of thermoplastic foam resin formed separately from the circumferential side wall is fitted into the bottom groove of the circumferential side wall, so that the circumferential side wall and the bottom plate are connected. A folding box made of synthetic resin, characterized in that the boxes are joined to each other at a heat-sealed part formed on the outer surface along each other's boundary line around the bottom. 2. The synthetic resin folding box according to claim 1 of the above-mentioned utility model registration claim, wherein the circumferential side wall has a wood grain pattern in the same direction on the outer surface.