JP7550435B2 - Cushioning Sheet - Google Patents

Description

This invention relates to a cushioning sheet used for packaging, wrapping, etc.

An example of the above-mentioned cushioning material is described in Patent Document 1 below. This cushioning material is formed by arranging many slits that extend in one direction in a paper sheet. Specifically, many slit rows are arranged side by side, with slit sections and non-slit sections arranged alternately in a straight line, and when arranged side by side, the middle positions of the slit sections in one slit row are lined up with the middle positions of the non-slit sections in the adjacent slit row.

This type of cushioning material is used after it is pulled and stretched in the direction that widens the slits, forming the slits into an approximately honeycomb shape. The pulling is done by hand, and the material is rolled or folded and used as a cushioning material for packaging, etc. As the cushioning material is made of paper, it is easy to handle, including when disposing of it.

Japanese Patent Application Publication No. 1-226574

However, because the slits must be stretched into a honeycomb shape before use, if the slits close when the box is rolled or folded to fill it with cushioning material, the cushioning capacity is reduced.

Therefore, the main objective of this invention is to provide a product that is easy to handle and also provides reliable cushioning.

The means for achieving this is a cushioning sheet made of a three-dimensional cushioning material in the form of a sheet made of a paper-based material, and a plant-derived exterior sheet sandwiched between both sides of the three-dimensional cushioning material.

In this configuration, the exterior sheet covers both sides of the three-dimensional cushioning material and holds the three-dimensional cushioning material in place.

According to this invention, the three-dimensional cushioning material is sandwiched between exterior sheets on both sides, so the shape of the three-dimensional cushioning material is maintained. Therefore, a reliable cushioning effect can be obtained simply by wrapping or stuffing the material. In addition, the three-dimensional cushioning material and exterior sheets are made from plants, so they are easy to handle.

FIG. FIG. FIG. FIG.

One embodiment of the invention is described below with reference to the drawings.

Figure 1 shows a partially cutaway front view of the buffer sheet 11. As shown in this figure, the buffer sheet 11 is formed into a sheet of an appropriate size and shape, and a three-dimensional buffer material 12 is inserted inside. Figure 2 shows a cross-sectional view of the buffer sheet 11.

That is, the cushioning sheet 11 is composed of a sheet-like three-dimensional cushioning material 12 and an exterior sheet 13 that sandwiches both sides of the three-dimensional cushioning material 12. The three-dimensional cushioning material 12 is made of a paper-based material, and the exterior sheet 13 is made of a plant-derived material.

First, we will explain the three-dimensional cushioning material 12.

The three-dimensional cushioning material 12 is obtained by stretching the cushioning material 21, which is a flat sheet material, as shown in FIG. 3(a).

The cushioning material 21 has numerous slits 22 arranged in a staggered pattern, each slit extending in one direction. The slits 22 are cuts that penetrate the material in the thickness direction.

The slits 22 in the cushioning material 21 are arranged at equal intervals in a straight line. If an imaginary straight line containing the slits 22 is taken as a slit row, then the slit row is made up of slits 22 of a predetermined length and non-slits 23 between the slits 22, as shown in an enlarged partial view in Figure 3(a). Many such slit rows are arranged side by side, and are arranged so that the midpoints of the slits 22 and non-slits 23 of adjacent slit rows are aligned with each other. In Figure 3(a), L indicates the slit length and W indicates the slit spacing.

Since this type of cushioning material 21 only has slits 22, it is simply a sheet and does not provide much cushioning effect. However, when the slits 22 are widened by stretching it in a direction perpendicular to the longitudinal direction of the slits 22, it becomes a three-dimensional cushioning material 12 with roughly honeycomb-shaped openings 24, as shown in the partially enlarged view of Figure 3(b). The part that forms these openings 24, i.e., the part other than the slits 22, is inclined diagonally relative to the surface direction of the cushioning material 21, providing a cushioning effect.

The material of the cushioning material 21 is paper-based as mentioned above, but specific examples include kraft paper, cardboard base paper, etc., and it is preferable that the material be sturdy.

Next, the exterior sheet 13 is composed of a single flat sheet. As mentioned above, the exterior sheet 13 is made of a plant-derived material, specifically, for example, paper or nonwoven fabric.

Various types of paper can be used. Examples of nonwoven fabrics include spunlace nonwoven fabrics and wet nonwoven fabrics made from various materials such as rayon and dry pulp. The paper and nonwoven fabrics may be coated.

The preferred exterior sheet 13 is one that is 90% or more plant-derived. Ideally, the buffer sheet 11 should be 100% plant-derived. However, depending on the raw materials and intended use, if the binder such as adhesive is not of plant origin, the sheet may not be strong enough to be suitable for use as a buffer sheet, and it may not be possible to completely eliminate non-plant-derived materials. However, if the sheet contains more than 10% plant-derived materials, it can no longer be considered a buffer material of plant origin, so as mentioned above, it is preferred that the exterior sheet 13 be 90% or more plant-derived.

One or two exterior sheets 13 are used, and the three-dimensional cushioning material 12 is inserted between the exterior sheets 13. When the exterior sheets 13 are bonded together and the three-dimensional cushioning material 12 is held in place by adhesive, adhesive 14 (see Figure 4) is applied to the inside surfaces of the two exterior sheets 13, and the three-dimensional cushioning material 12 that fits inside the exterior sheets 13 is attached.

As shown in Figure 4, the adhesive 14 is applied to the outer peripheral edge 31 and inner peripheral portion 32 of the exterior sheet 13. The adhesive 14 on the outer peripheral edge 31 is mainly for joining the exterior sheets 13 together, while the adhesive 14 on the inner peripheral portion 32 is for joining the three-dimensional cushioning material 12. The adhesive 14 on the inner peripheral portion 32 can be applied over the entire surface, but it is preferable to apply it partially. This is to allow freedom of deformation while still restraining the three-dimensional cushioning material 12.

In the example of Figure 4, the adhesive 14 on the inner circumference 32 is applied to an appropriate width on two diagonals of the rectangular exterior sheet 13, but any appropriate application pattern can be used, such as drawing parallel lines or multiple circles.

The three-dimensional cushioning material 12 is attached to the adhesive 14 applied to the exterior sheet 13, mainly to the inner periphery 32, and sandwiched between the sheets. The exterior sheets 13 are then joined together with the adhesive 14 on the outer periphery 31, completing the cushioning sheet 11.

A test was conducted to verify how the cushioning capacity of the cushioning sheet 11 configured as described above differs depending on the shape of the slits 22 in the cushioning material 21.

The test involves dropping an egg wrapped in a cushioning sheet 11 from a specified height onto a wooden table to see if the egg cracks. The egg is wrapped in approximately a single layer. Large eggs (64g or more and less than 70g) were used, and the egg was dropped from a height of 5cm above the table. The test was performed five times on the same specimen.

The material of the buffer sheet 11 is 50 g/ ^m2 kraft paper for both the three-dimensional buffer material 12 and the exterior sheet 13. In other words, the material of the buffer sheet 11 is all vegetable-based except for the adhesive 14.

The slit length L and slit interval W of the cushioning material 21 in the test specimen (see Figure 3) are as shown in Table 1. The slit length L is in the range of 2 mm to 60 mm, and the slit interval W is in the range of 0.5 mm to 15 mm, and the samples were made by appropriately combining them as shown in Table 1.

試験体Ｎｏ．１は、スリット長さＬが２ｍｍで、スリット間隔Ｗが１ｍｍである。つまり、スリット長さＬ：スリット間隔Ｗは２：１であり、いずれの値もＬサイズの鶏卵に比してきわめて小さい。

Test specimen No. 1 has a slit length L of 2 mm and a slit interval W of 1 mm. In other words, the slit length L:slit interval W is 2:1, both of which are extremely small compared to an L-sized chicken egg.

Test specimen No. 2 has a slit length L of 3 mm and a slit interval W of 1 mm. In other words, the slit length L:slit interval W ratio is 3:1, and the value of the slit interval W, which is particularly related to the thickness of the three-dimensional cushioning material 12, is extremely small compared to an L-sized chicken egg.

Test specimen No. 3 has a slit length L of 5 mm and a slit interval W of 0.5 mm. In other words, the slit length L:slit interval W ratio is 10:1, and the value of the slit interval W, which is particularly related to the thickness of the three-dimensional cushioning material 12, is extremely small compared to an L-sized chicken egg.

Test specimen No. 4 has a slit length L of 5 mm and a slit interval W of 1 mm. In other words, the slit length L:slit interval W ratio is 5:1, and the value of the slit interval W, which is related to the thickness of the three-dimensional cushioning material 12, is twice as large as that of test specimen No. 3, but the slit length L, which is related to the opening of the slits in the three-dimensional cushioning material 12, is the same as that of test specimen No. 3.

Test specimen No. 5 has a slit length L of 5 mm and a slit interval W of 2 mm. In other words, the slit length L:slit interval W ratio is 5:2, and the value of the slit interval W related to the thickness of the three-dimensional cushioning material 12 is twice as large as that of test specimen No. 4.

Test specimen No. 6 has a slit length L of 10 mm and a slit interval W of 2 mm. In other words, the slit length L:slit interval W ratio is 5:1, and compared to test specimen No. 4, the slit length L, which is related to the opening of the slits in the three-dimensional cushioning material 12, and the slit interval W, which is related to the thickness of the three-dimensional cushioning material 12, are both twice as large.

Test specimen No. 7 has a slit length L of 20 mm and a slit interval W of 5 mm. In other words, the slit length L:slit interval W ratio is 4:1, and compared to test specimen No. 6, the value of the slit length L, which is related to the opening of the slits in the three-dimensional cushioning material 12, is twice as large, and the value of the slit interval W, which is related to the thickness of the three-dimensional cushioning material 12, is 2.5 times larger.

Test specimen No. 8 has a slit length L of 35 mm and a slit interval W of 7 mm. In other words, the slit length L:slit interval W ratio is 5:1, and compared to test specimen No. 7, the value of the slit length L related to the opening of the slits in the three-dimensional cushioning material 12 is 1.75 times, and the value of the slit interval W related to the thickness of the three-dimensional cushioning material 12 is 1.4 times.

Test specimen No. 9 has a slit length L of 35 mm and a slit interval W of 10 mm. In other words, the slit length L:slit interval W ratio is 7:2, and compared to test specimen No. 8, only the value of the slit interval W, which is related to the thickness of the three-dimensional cushioning material 12, was made 3 mm longer.

Test specimen No. 10 has a slit length L of 40 mm and a slit interval W of 7 mm. In other words, the slit length L:slit interval W ratio is 40:7, and compared to test specimen No. 8, only the slit length L value, which is related to the opening of the slits in the three-dimensional cushioning material 12, is longer by 5 mm, and only the slit interval W value, which is related to the thickness of the three-dimensional cushioning material 12, is shorter by 3 mm.

Test specimen No. 11 has a slit length L of 50 mm and a slit interval W of 10 mm. In other words, the slit length L:slit interval W ratio is 5:1, and compared to test specimen No. 9, only the slit length L value related to the opening of the slits in the three-dimensional cushioning material 12 was made 15 mm longer.

Test specimen No. 12 has a slit length L of 60 mm and a slit interval W of 10 mm. In other words, the slit length L:slit interval W ratio is 6:1, and compared to test specimen No. 11, only the slit length L value related to the opening of the slits in the three-dimensional cushioning material 12 was made 10 mm longer.

Test specimen No. 13 has a slit length L of 50 mm and a slit interval W of 15 mm. In other words, the slit length L:slit interval W ratio is 10:3, and compared to test specimen No. 12, the value of the slit length L, which is related to the opening of the slits in the three-dimensional cushioning material 12, is 10 mm longer, and the value of the slit interval W, which is related to the thickness of the three-dimensional cushioning material 12, is 5 mm longer.

In addition, for test specimen No. 13, the slit spacing W related to the thickness of the three-dimensional cushioning material 12 was 15 mm, making it bulky and difficult to wrap a chicken egg in, so the test was not performed.

The test results showed that test specimen No. 1 cracked all five eggs. Test specimen No. 2 cracked three eggs, test specimen No. 3 cracked five eggs, test specimen No. 4 cracked two eggs, test specimen No. 11 cracked one egg, and test specimen No. 12 cracked four eggs.

On the other hand, in test specimens No. 4 to No. 10, no eggs cracked even once.

From these results, it can be seen that when the slit spacing is less than 1 mm and when the slit length is less than 3 mm, it is difficult for the eggs to function as a cushion (test specimens No. 1 and 3). This can also be seen from a comparison of test specimens No. 4 and No. 5. In other words, the slit length L of both test specimens No. 4 and No. 5 is 5 mm, but the slit spacing W of test specimen No. 4 is half that of test specimen No. 5, at 1 mm. While no eggs were cracked in test specimen No. 5, two eggs were cracked in test specimen No. 4.

Comparing the results of specimens No. 4, 6, 8 and 11, which have a ratio of slit length L to slit spacing W of 5:1, it is clear that all of them have a cushioning function, but in specimen No. 4, which has a small slit spacing W value, two of the five eggs were broken. In specimen No. 11, which has a large slit length L value, one egg was broken. This shows that the cushioning function deteriorates when either the slit length L or the slit spacing W is too small or too large beyond a certain range.

Although it is not clear from the test results, if the slit spacing exceeds 10 mm, the material becomes too bulky to be used as a cushioning material. As for the slit length, if it exceeds 50 mm, it will not function as a cushioning material for chicken eggs.

Based on these results, it is preferable that the slit spacing W of the cushioning material 21 in the cushioning sheet 11 is 1 to 10 mm, preferably 1 to 8 mm, and the slit length L is 3 to 50 mm, preferably 5 to 35 mm.

The cushioning sheet 11 configured as described above is used to wrap an item or to stuff it between an item and a container during packaging or wrapping. When wrapping or stuffing, it can be folded or rolled as necessary, and any unnecessary parts can be cut off.

The buffer sheet 11 has a structure in which both sides of the three-dimensional buffer material 12 are sandwiched between the exterior sheets 13, so the shape of the three-dimensional buffer material 12 is maintained, and the buffer function can be exerted simply by wrapping or stuffing it, making it easy to handle. Moreover, since the three-dimensional buffer material 12 is made of a paper-based material and the exterior sheets 13 are derived from plants, it can be disposed of as paper without any additional work when no longer needed, making it easy to handle.

The above configuration is one embodiment of the present invention, and the sheet material of the present invention corresponds to the aforementioned cushioning material 21, but the present invention can also employ other configurations.

For example, the three-dimensional cushioning material 12 may be something other than a honeycomb three-dimensional material.

In addition, if the exterior sheet 13 is made of a breathable material or has ventilation holes or cutouts (windows), it can be suitable for packaging items that are sensitive to moisture, for example.

The three-dimensional cushioning material 12 may be provided in multiple layers.

In the above example, two exterior sheets 13 are shown bonded together, but it is also possible to fold one exterior sheet 13 in half and provide the three-dimensional cushioning material 12 inside.

The three-dimensional cushioning material 12 and the exterior sheet 13 can also be joined by welding, etc.

In addition to being used as a sheet, the cushioning sheet 11 can also be assembled into an envelope-like shape and used as a packing or wrapping material for envelopes, etc.

11: Cushioning sheet 12: Three-dimensional cushioning material 13: Outer sheet 21: Cushioning material 22: Slit

Claims (3)

It is composed of a sheet-shaped three-dimensional cushioning material made of a paper-based material and a plant-derived exterior sheet sandwiched between both sides of the three-dimensional cushioning material .
The exterior sheets are joined to each other by an adhesive applied to the outer peripheral edge portions of the exterior sheets,
The exterior sheet and the three-dimensional cushioning material are joined by an adhesive partially applied to the inner periphery of the exterior sheet.
Cushioning sheet. 2. The buffer sheet according to claim 1, wherein the exterior sheet contains 90% or more of plant-derived components. The three-dimensional cushioning material is a sheet material having a number of slits extending in one direction arranged in a staggered pattern, which is stretched to form a three-dimensional shape,
The interval between the slits is 2 mm or more and less than 10 mm, and the length of the slits is 10 mm or more and less than 50 mm ,
The ratio of the slit interval to the slit length is 1:5.
The buffer sheet according to claim 1 or 2.

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