JPH0130383Y2 - - Google Patents

Description

[Detailed explanation of the idea]

This invention suppresses cracking in cases where packaging materials made of thermoplastic resin foam moldings used in combination with cardboard boxes or alone as packaging materials for home appliances, etc. crack when subjected to impact loads such as being dropped. The present invention relates to a cushioning packaging material having a molded body shape. Packaging materials using thermoplastic resin foam moldings can be divided into two types depending on how they are used: full-cover type and partial-cover type, but in both cases, their function is to fix the product and stabilize its position during the transportation process. It also has a cushioning function when it receives impact loads due to falls, etc. Particularly in normal cases, when subjected to strong impact loads such as being dropped, thermoplastic resin foam molded articles are subject to considerable damage due to cracking, although the degree varies depending on the type of molded article. However, regardless of the damage caused by cracking, the packaging material must not impair the product fixing and positional stability functions even after receiving an impact load. Therefore, in the past, drop tests have been carried out to investigate cases where cracking of the packaging material, which occurs when impact loads predicted during the transportation process are applied, may impair the product fixation and positional stabilization functions. In order to prevent this, various measures have been taken, such as lowering the expansion ratio of thermoplastic resin foam moldings and increasing the wall thickness. However, these measures naturally lead to an increase in the amount of foamed molding material used, and also bring about various disadvantages such as an increase in packaging time and a reduction in the original impact function. Therefore, the inventors of the present invention focused on the above-mentioned drawbacks of the conventional technology, and conducted various studies to improve them. In cases where the greatest amount of cracking damage occurs when the product falls on the edge, a groove-shaped cut-out may be provided at a position near the edge of the packaged object in parallel to the edge of the packaged part or all, or as a further improvement. In addition to the above-mentioned groove-shaped thinning, we have proposed a structure in which thinning is provided diagonally at the edge corner near the edge of another surface. (Refer to Japanese Utility Model Publication No. 61-45016.) However, as a result of repeated studies and repeated experiments on the dispersion and propagation of stress during falls from ridges, the packaging materials with the above-mentioned proposed structures were improved to some extent. We have come to the conclusion that even if it is, there is still a problem with the spread to surfaces that do not have diagonal meat stealing. That is, the present invention aims to further improve the packaging material proposed above based on such knowledge. Although it has a diagonal ridge, it has only one surface with a diagonal ridge, whereas the ridge is obtained by the intersection of three ridges on all the surfaces of the three walls that intersect with each other. It is characterized in that, in the vicinity of the corner intersection, each ridge angle formed by the intersection of two ridge lines is used as an apex angle, and a fillet is provided diagonally opposite to each ridge angle. Hereinafter, specific embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Figure 1 shows the state in which a packaged article using the shock-absorbing packaging material of the present invention falls in the direction of the ridge and receives an impact. A cushioning packaging material made of a resin molded body, 3 an exterior cardboard box, and 4 a ground plane. In such a state as shown in FIG. 1, the compressive deformation of the cushioning packaging material 2 when it falls from the edge usually occurs predominantly at the edge, so that each part that forms the falling edge is A force that tries to push the molded product open acts on the approximately right-angled surface of This creates a situation where extremely large cracks occur due to concentration. Therefore, the cushioning packaging material of the present invention is intended to reduce and disperse the concentration of bending stress at the corners as much as possible. FIGS. 2 to 4 show specific examples of the cushioning packaging material of the present invention. First, FIGS. 2 and 3 are an example of this, and of course, on the outer surface sides of at least three intersecting wall surfaces 2a, 2b, 2c constituting the cushioning packaging material 2, near the corner P where the ridge lines intersect, respectively. A ridge angle formed by two ridge lines formed by two adjacent wall surfaces is used as an apex angle, and a fillet cutout 5 formed of an elongated recess is provided diagonally opposite to the ridge angle formed by two ridge lines of two adjacent wall surfaces. Here, diagonal means that it is not parallel to either of the two sides that sandwich the ridge angle, and preferably it is part of the hypotenuse of a right triangle having these two sides as its two sides. There is no particular restriction on the shape of the meat stripping in the above configuration, and it may be a collection of a plurality of hemispherical small recesses 5', for example, as shown in FIG. 4, in addition to the elongated recess 5. Alternatively, it may be a triangular recess 5'' as shown in FIG. 5, or any other shape as long as it cuts the edge and prevents the propagation of stress that occurs during compressive deformation. However, in order to prevent the propagation of such stress, it is effective to provide it diagonally at a position as close as possible to the ridge angle, and therefore, the position is such that the wall thickness of the molded cushioning packaging material 2 is equal to t. When, the distance d from the corner intersection P on the outer surface in contact with the packaged object is in the range of 0.5t or more and 3t or less,
In particular, it is preferable that t≦d≦2t, and the depth of the recess is also preferably 4/5t or less. It is preferable that the cross-sectional shape of the meat-stealing recess has a curved inner bottom as much as possible, but it may of course have a rectangular cross-sectional shape. Also, meat stealing 5,
5', 5'' are not limited to the outer side but may be on the inner side, or both may be mixed.Furthermore, in the case of the present invention, the diagonally provided meat strips 5, 5', 5'' will be explained. However, this does not negate the use of groove-shaped meat stripping parallel to the ridge line. In addition, other arbitrary shapes can also be used in combination. Thus, due to the formation of the flesh stripping in the present invention as described above, even if there is a force trying to push the molded product open during a drop impact as described above, the molded product will not be pushed open in the ridge direction with respect to the product contact surface. This force can be absorbed by the thinning on both sides, and thereby the bending stress can be dispersed, and furthermore, the propagation of stress can be prevented by the thinning on the other surface, These factors combine to maintain a shape closer to that of simple compression in the ridge portions, thereby significantly suppressing cracking damage, compared to the case of groove-like thinning on both sides according to the above-mentioned proposal. Hereinafter, the cushioning packaging material of the present invention will be further described with respect to other packaging materials, namely corner pat B made of a blank foamed resin molding having no flesh pilferage and the corner pat of Utility Application No. 159780 filed by the present applicant. C
The results of a drop test are also shown. In the table, A is the case where the cushioning packaging material of the present invention is used. The test was conducted using cargo weighing 10 kg as a product.
Each corner piece of 110 x 110 x 110 mm and 30 mm wall thickness was placed in contact with each corner and covered with cardboard paper, and as shown in Figure 1, it was dropped along the ridge line to determine the maximum height of the cushioning material cracking (scattering) due to one corner drop. It was measured.

[Table] From the above table, it is confirmed that the shock-absorbing packaging material of the present invention has a significantly improved cracking and damage suppressing effect compared to the previous one. As described above, the packaging material of the present invention is a packaging material having three wall surfaces that intersect with each other, and each surface of the packaging material near the corner intersection of the packaged object is provided with diagonal cuts at the ridge angles. When falling from a ridge, the thermoplastic foam absorbs the force that tries to push the molded product open even if it acts on each approximately right-angled surface that forms the ridge, and disperses the bending stress. When falling on a ridge, where the greatest damage from cracking occurs in resin moldings,
Not only is it possible to suppress the damage caused by cracks in the packaging material due to drop impact, but the dispersion of stress is also prevented by the propagation prevention thinning of the other surfaces, so the effect of suppressing cracks is even more reliable. Then,
Moreover, unlike lowering the foaming ratio or increasing the wall thickness of the molded product, it does not increase the amount of foam molding material used, and it also achieves savings in the same material, making it extremely economical and It is an extremely effective packaging material in practical terms.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing a state in which a product packed by the packaging material falls from the edge, Fig. 2 is a perspective view showing an example of the cushioning packaging material of the present invention, Fig. 3 is an external view of the same, Figs. FIG. 5 is an external view showing a modification of the cushioning packaging material of the present invention. 1... Item to be packaged, 2... Cushioning packaging material, 2a, 2
b, 2c...Each wall surface, 3...Exterior cardboard box,
5,5'...Meat stealing.

Claims (1)

[Claims for Utility Model Registration] 1. A packaging material made of a thermoplastic resin foam molding, having at least three walls that intersect with each other, and which partially or completely adheres to the outer surface of the packaged object during packaging. In, among the three surfaces, a surface formed by the intersection of two ridge lines is formed on each surface of the three mutually intersecting wall surfaces near the corner where each ridge line formed by two mutually adjacent wall surfaces intersects intensively. A cushioning packaging material characterized in that each edge angle is an apex angle, and a fillet is provided diagonally opposite and diagonally to each edge angle. 2 When the wall thickness of the packaging material is t, the meat stealing diagonal to the edge angle is from the corner intersection on the outside surface side that contacts the packaged object
The cushioning packaging material according to claim 1, which is provided at a distance of 0.5 t or more and 3 t or less, and whose depth is 4/5 t or less. 3. The utility model registration claim described in claim 1 or 2, in which the diagonal filleting of the ridge angle is an elongated concave part in a part of the oblique side of a triangle whose two sides are the two sides that sandwich the ridge angle. Buffer packaging material. 4 Utility model registration claim Paragraph 1, in which the diagonal flesh loss on the ridge angle is a collection of a plurality of small concave holes formed in a part of the hypotenuse of a triangle whose two sides are the two sides that sandwich the ridge angle. Or the cushioning packaging material described in item 2.