JPS6149092B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a cushioning material, and in particular to a cushioning material in which long pieces of foam are connected in a bridge shape in the short direction by using a die in which extrusion grooves are connected in a staggered manner. Relating to something characterized by obtaining.

Conventionally, various methods for manufacturing sheet-like cushioning materials have been proposed.

For example, there is a method of manufacturing a sheet-like cushioning material by providing grooves on each surface of a set of dies, assembling the dies so that there is a gap between the surfaces corresponding to the sheet body, and extruding molten resin from the dies.

However, this method has disadvantages in that 32 portions of the sheet main body are produced as shown in FIG. 7, which requires a larger amount of raw material, and increases the cross-sectional height. In the present invention, the above-mentioned drawbacks are solved by using a die having extrusion grooves with continuous holes in a staggered pattern, and the resulting cushioning material has no equivalent to the sheet body in the above-mentioned conventional example, and only has convexities. It consists of

That is, the present invention consists of a set of dies in which a plurality of extrusion grooves are cut on each surface in the extrusion direction, and when the two surfaces are overlapped, in a cross section perpendicular to the extrusion direction, The foamable molten resin is extruded from a die in which both opposing surfaces form substantially the same surface and the extrusion grooves are arranged in a staggered manner with the extrusion grooves having alternately overlapping ends and continuous holes to form a long piece of foam. A sheet characterized by obtaining a sheet-like cushioning material in which parts of the short-side direction are alternately overlapped to form a sheet-like object, and the upper and lower surfaces of the sheet-like object are wave-shaped. This is a method for manufacturing a shaped cushioning material.

The present invention will be explained below based on the illustrated embodiments. FIG. 1 is a conceptual diagram of an extruder used in carrying out the present invention. The extruder 100 includes a raw material input hopper 102, a motor 101, and a die 103.
The material is melted inside and extruded as a foam from a die 103 using a screw (not shown).

FIG. 2 is a front cross-sectional view showing the basic shape of the die used in the present invention, and extrusion grooves 3 and 4 are dug in the respective surfaces of the dies 1 and 2 in the extrusion direction, and the extrusion grooves are formed as shown in the figure. The opposing surfaces on which the grooves 3 and 4 are dug form the same plane, and the ends of the extrusion grooves 3 and 4 are alternately overlapped and connected, so that the upper and lower extrusion grooves are arranged in a staggered manner. That is, the extrusion grooves 3 and 4 arranged in a staggered manner are connected to each other at the overlapping portions 5 at their ends, and both dies 1 and 2 are fixed in contact with each other.

FIG. 3 is an explanatory diagram of the width of the extrusion groove. In this figure, the conditions under which the extrusion grooves can be arranged in a staggered manner will be explained.

The width of the extrusion groove 3 is l ₁ , the interval between the extrusion grooves 3 and 3 is l ₂ ,
Assuming that the width of the extruded groove 4 is l ₄ and the interval between the extruded grooves 4 is l ₃ , grooves with continuous holes in a staggered pattern can be obtained by simultaneously satisfying the following formula.

l ₁ > l ₃ l ₄ > l ₂ From the above, it is natural that the width l ₁ and the width l ₄ and the interval l ₂ and the interval l ₃
It will be understood that the relationship may be of the same size or of different sizes.

FIG. 4 shows another cross-sectional shape of the extrusion groove, in which the cross-section is semicircular. It goes without saying that the cross-sectional shape of the extruded groove can be triangular, trapezoidal, or other shapes.

The above example shows the case of a so-called "flat die", but the case of a "circular die" is shown in the fifth example.
As shown in the figure.

FIG. 6 is a perspective view of the sheet-like cushioning material produced using the die shown in FIG.
A sheet-like cushioning material is formed in which the elongated pieces 31 extruded from 4 and 4 are overlapped and fused to each other at portion B in the short side direction thereof.

FIG. 7 is a front sectional view of a sheet-like cushioning material obtained by a conventional method. A shape having protrusions 31 on the upper and lower surfaces of the sheet body 32 is obtained. Figure 8 is the 4th
A front cross-sectional view of a sheet-like cushioning material produced using the die shown in the figure, and FIG. 9 is a front cross-sectional view of a sheet-like cushioning material obtained when produced using a die having a different extrusion groove shape. shows.

In the present invention, as described above, by using a special die in which extrusion grooves dug on the opposing surfaces of a set of dies are arranged in a staggered manner, the long pieces of foam are It is easy to obtain a corrugated sheet-like material in which parts of the wafers are alternately overlapped, and since this sheet-like material is composed only of long pieces, less raw material is required compared to the conventional method. It has the effect of providing a sheet-like cushioning material, and
The obtained cushioning material differs from the conventional sheet-like cushioning material in which the long pieces form protrusions on the upper and lower surfaces of the sheet body, and does not have a sheet body, but is composed of long pieces connected in a bridge shape in the direction of the short side. Therefore, it is an extremely effective invention that can provide an excellent cushioning material that is highly flexible in the width direction and has excellent cushioning properties not only due to the foam but also from its structure.

[Brief explanation of the drawing]

Fig. 1 is a conceptual diagram of an extruder used in carrying out the present invention, Fig. 2 is a front sectional view showing the basic shape of the die, Fig. 3 is an explanatory diagram of the width of the extrusion groove, and Fig. 4 is an illustration of the width of the extrusion groove. Another sectional shape diagram, FIG. 5 is an explanatory diagram in the case of a circular die, FIG. 6 is a perspective view of a cushioning material manufactured using the die shown in FIG. 2, and FIG. 7 is a diagram of a cushioning material obtained by a conventional method. 8 and 9 are front sectional views of a cushioning material obtained with another extruded groove shape. 1/2...Dice, 3/4...Extrusion groove, 5...
Overlapping part, 31... Long piece, 100... Extruder.

Claims (1)

[Claims] 1 Consists of a set of dies with multiple extrusion grooves dug on each surface in the extrusion direction, and when the above two surfaces are overlapped, both surfaces face each other in a cross section perpendicular to the extrusion direction. The foamable molten resin is extruded from dies in which the extrusion grooves are arranged in a staggered manner with the extrusion grooves forming substantially the same surface and having continuous holes with alternate ends, so that the long pieces of foam are formed in the short direction and Manufacture of a sheet cushioning material characterized by obtaining a sheet-like cushioning material in which parts of the short sides are alternately overlapped to form a sheet-like object, and the upper and lower surfaces of the sheet-like object are wave-shaped. Method.