JPH0242612Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to an integral foam corrugated board with a special shape that has an excellent function as a cushioning material, such as fruits, valuables, and precision machinery. It can be used as packaging material.

[Prior Art and Problems of the Present Invention] Many cushioning materials for packaging made of foamed plastic have been devised and are commercially available in large numbers. Each has its advantages and disadvantages, but the goal is to
The objective is to obtain a product that is light and has good cushioning properties using less material.

The present inventor previously devised a sheet-like cushioning material with a special shape. (Utility Model Publication No. 58-21420) This device is constructed in such a way that parts of the elongated pieces are alternately overlapped to form a sheet shape, and the upper and lower surfaces of the sheet shape are corrugated. In a typical embodiment (see FIG. 1 of the publication), the cross-sectional shape of the elongated piece, which is a unit constituting the corrugated plate, is rectangular. As other examples, a semicircular shape (FIG. 3) and a triangular shape (FIG. 4) are also disclosed.

The object of the present invention is to further improve the cross-sectional shape based on the idea of this sheet-like cushioning material, and to obtain a corrugated plate that is even more superior in terms of function and easy to manufacture.

[Means for solving the problem] The present invention provides an elongated piece 2 having an arc-shaped cross section with a concave top and a bottom concave
This integral foam corrugated board is characterized in that it has a shape in which it overlaps alternately with other elongated pieces 2' on the inner surface of a circular arc, and has a multi-layered shape.

FIG. 1 is a perspective view of the foam corrugated plate of the present invention. In order to make it easier to understand the shape of the corrugated foam board 1, it will be explained with reference to FIG. 2, which shows it broken down into long structural units for convenience. The long piece 2 has a cross section parallel to the short piece 3 having an upwardly convex and downwardly concave arc shape, and a cross section parallel to the long side 4 having a linear shape. This elongated piece 2 is partially connected to the other elongated piece 2' on the inner surface 5 (lower surface) of the arc at the end of the long side.
The other elongated piece 2' overlaps with the upper surface of the long side end 5', and the other elongated piece 2' overlaps with another elongated piece (shown as 2'') on the upper surface of the long side end 5''. , in the same way, upwardly convex and downwardly concave elongated pieces with arcuate cross-sections are alternately overlapped with other elongated pieces on the inner surface of the arc,
Constructs a shape that connects many. The other elongated piece 2' to be combined with the elongated piece with concave and concave tops is normally preferably a long piece with concave and convex tops and bottoms that have an arcuate cross section as shown in the figure, but this does not impede the purpose of the invention. Other cross-sectional shapes, such as a nearly flat shape, can also be used. There is no particular restriction on the thickness of the elongated piece 2 with convex and concave sides and the other elongated pieces 2', but when used for packaging lightweight items, it is preferably about 1 mm to 10 mm.

The foam corrugated board of the present invention does not need to have a structure in which long pieces are stacked and glued together, but can be made by extruding the foamable plastic raw material from a specially shaped mouthpiece using an extrusion molding machine. A monolithic foam corrugated board is obtained with the characteristic shape of the invention. For example, if a foamable plastic raw material is extruded through a die hole (the front view is shown in FIG. 3) which is a combination of die plates 7 and 7' having grooves 6 and 6' having a rectangular cross section, a long piece can be formed. The outer part of is in a more foamed state than the inner part, and as a result, the long piece curves outward by itself, and the top-convex-down-concave long piece and the top-convex-bottom-convex long piece curve around the inside surface of the arc. A corrugated foam plate having a shape characteristic of the present invention, in which a plurality of corrugated foam plates are overlapped alternately and are connected in large numbers, is obtained. of course,
Since it is a foam with a high expansion ratio that can be used as a cushioning material, the term ``arc-shaped'' is not a strict term; the long pieces of the structural unit of the corrugated plate are not flat, but ``round. ” represents the state. If it is desired to manufacture a long piece with a greater degree of curvature, a curved die hole may be used.

If a so-called circular die, the front view of which is shown in FIG. 5, is used, a tubular corrugated plate as shown in FIG. 6 can be obtained. This can be used as a cushioning material in its tubular form, or it can be cut open and made into a flat corrugated plate. In this case, unlike the flat plate using the cap holes shown in FIG. 3, the tube does not have a uniform curvature vertically, but the curvature on the outside of the tubular shape is large, while the inside has a small curvature or a shape close to a flat surface. If the circular die shown in FIG. 5 is further rotated, a tubular twisted corrugated plate as shown in FIG. 7 can be obtained. If this material is used as a cushioning material in its tubular form, the upper and lower corrugated plates intersect, which increases the cushioning effect.

The sheet shown in Figure 3 of Utility Model Publication No. 58-21420 shown above is similar to the present invention in that it has a series of round, wavy protrusions, but the cross section of the structural unit is not arcuate but semicircular. Therefore, this sheet is
It does not have an arcuate concave surface that acts to absorb shock through deformation. Naturally, they do not have a shape that partially overlaps on the inner surface (concave surface) of the arc. Furthermore, since the corrugated sheet is a series of semicircles, the pitch of the corrugations is limited by the thickness of the sheet and must be close to this. It is also possible to choose a relatively large wave pitch with a small sheet.

The invention is applicable to a variety of plastic foams that can be selected by those skilled in the art. Typical plastic foams are described in the collection of well-known and commonly used techniques (foam molding), and suitable examples include extruded polystyrene foam and polyethylene foam.

[Function] Since the present invention is constructed as described above, the curvature of the arc-shaped long piece has a buffering effect, and when a load is applied and the curvature becomes flat as shown in Fig. 4, the long piece The overlapping part supports the load. Of course, since the entire body is made of foam, it goes without saying that it has a cushioning effect as a whole.

[Effects of the invention] As described above, the foam corrugated plate of the invention has a dual cushioning effect, one due to the curvature of the long arcuate piece and the other due to the foam itself, and is soft and protects the packaged items. do.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the foam corrugated plate of the present invention;
The figure is an explanatory perspective view of a long piece of the structural unit of the foam corrugated board of the present invention, FIG. 3 is a front view of the extrusion hole for manufacturing the foam corrugated board of the present invention, and FIG. FIG. 2 is a perspective view of the corrugated foam board of the present invention flattened under load; FIG. 5 is a front view of another example of the extrusion hole for producing a corrugated foam board of the present invention, FIG. 6 is a partial perspective view of another example of the corrugated foam board of the present invention, and FIG. FIG. 2 is a partial perspective view of yet another example of the foam corrugated plate of the present invention. 1 is a foam corrugated board, and 2, 2'' is a long piece of a structural unit of the foam corrugated board.

Claims (1)

[Scope of utility model registration request] Convex and concave elongated pieces with arc-shaped cross sections alternately overlap with other elongated pieces on the inner surface of the arc,
An integral foam corrugated board characterized by a multi-connected shape.