JPH0326146Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Industrial Application Field) This invention is designed to prevent packaging materials made from thermoplastic resin foam moldings, which are used in combination with cardboard boxes or alone as packaging materials for home appliances, etc., to crack when subjected to impact loads such as being dropped. The present invention relates to a shock-absorbing packaging material made of a molded body that suppresses cracking. (Prior art) Packaging materials using thermoplastic resin foam moldings can be divided into two types depending on the usage type: full-cover type and partial-type. It has a fixing and positional stabilization function, as well as a buffering function when receiving an impact load due to a fall, etc. Particularly in normal cases, when a thermoplastic resin foam molded product is subjected to a strong impact load such as a drop, the molded product is damaged by cracking to some extent, although the degree varies depending on the type of molded product. However, regardless of the damage caused by cracking, the packaging material must not impair the product fixing and positional stability functions even after being subjected to 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 foam molding material used, and also bring about various drawbacks such as an increase in the number of packaging materials and a reduction in the original cushioning function. Therefore, the inventors of the present invention focused on the above-mentioned drawbacks of the conventional technology, and in order to solve these problems, we first focused on packaging materials made of thermoplastic resin foam moldings due to ridge falls, where the most damage caused by cracking occurs. In this method, a groove-like meat stripping is provided at a position near the ridge of the packaged object in parallel with the edge of the packaged object over a part or all of the object, and in addition to the groove-shaped flesh stripping, compressive deformation We proposed that a structure to prevent stress propagation be provided diagonally to the ridge angle on another surface. (Problem that the invention aims to solve) However, after further consideration and repeated consideration of the distribution and propagation of stress when falling from a ridge, it was found that the packaging materials related to each of the above proposals were themselves improved. However, we have found that there is still room for research into the propagation of stress to each surface, and that further improvements can be made. That is, the present invention is based on this knowledge and aims to further improve each of the packaging materials proposed above. (Means for Solving the Problems) That is, the present invention, which meets the above object, is made of a thermoplastic resin foam molded body, has at least three surfaces that intersect with each other, and when packed, the outer surface of the packaged object is partially or In a packaging material that is completely covered, an object-contacting surface of the required width adjacent to two ridges formed by the intersection of at least one surface with the ground adjacent to each other on the inner surface side. The present invention is characterized in that a thin-walled portion consisting of a thin-walled portion of a required extent and having a step is provided, leaving a gap. Here, the above-mentioned packaging material that has three surfaces that intersect with each other and that is partially or completely applied to the outer surface of the packaged object includes not only a so-called corner pat that is applied only to the corner part, but also , those that include such corner parts and have an integral edge part that also adheres to the ridge of the packaged object, and box-shaped items that cover half or the whole of the packaged object, Includes all intended packaging materials. (Function) Normally, a packaging material having at least three sides that intersect with each other is used as a cushioning material by coming into contact with the corner of the packaged object. The force that tries to push open the inner wall surface outwards creates bending stress centered on the corners, causing cracks in the packaging material. However, in the case of the cushioning packaging material of the present invention, there is a stepped thin wall surface that spreads over the entire surface except for the required width portion, and when the bending stress is generated due to a fall impact and the cushioning packaging material is pushed open, When the thin wall tries to close inward due to the entrainment phenomenon, the force to push it open is reduced, weakening the bending stress, creating a partial simple compression phenomenon, and suppressing the occurrence of cracks. (Example) Hereinafter, specific embodiments of the present invention will be described in further detail with reference to the accompanying drawings. Figure 1 shows an example in which the shock-absorbing packaging material of the present invention is used for packaging electrical products.In order to buffer and secure the upper left and right corners and ridges of the packaged product 1, the corners and ridges are integrated into these areas. The pad, that is, the packaging material 2 is in contact with it. Here, the above-mentioned packaging material 2 has both corner and ridge portions that are integrally cushioned and fixed, and the corner portion is provided with a cushioning packaging according to the present invention, which has three surfaces orthogonal to each other so as to be in contact with at least three surfaces thereof. Contains material. Therefore, in the following, we will particularly describe the packaging material that is attached to the corner parts, which is the main part of the present invention.
A description of the ridge will be omitted. Figure 2 shows the state in which the packaged item as shown in Figure 1 above falls in the direction of the ridge and is subjected to impact, which is the basic principle of compressive deformation in the present invention. is shown. That is, in the figure, 1 is an object to be packaged, 2 is a cushioning packaging material of the present invention made of a thermoplastic resin foam molding, and 3 is a packaging material of the present invention.
4 is an exterior cardboard box, and 4 is a ground plane. Compressive deformation of foam packaging materials such as foam packaging materials using such illustrated cardboard boxes and foam packaging materials such as sleeve packaging is usually dominant at the ridge portion as a general tendency of the ridge. As a result, a force that attempts to push open the inner wall surface of the molded body acts on the two approximately perpendicular surfaces forming the falling ridge portion. As a result, when using the method shown in Figure 2, extremely large cracks occur due to the bending stress concentrated at the corners due to the force that tries to push open the molded product when subjected to a drop impact load. A situation arises in which Therefore, the shock-absorbing packaging material of the present invention is provided with a structure that weakens the bending stress in order to suppress the occurrence of such cracks. 3A to 3C disclose various embodiments of the cushioning packaging material of the present invention, each of which is provided with a crack-preventing structure depending on the usage mode. In other words, the structures shown in Figures A, B, and C differ only in the number of surfaces on which the meat is removed, but the structure of the meat is removed in common. The entire surface of the package is formed as a thin-walled portion 8, except for a necessary contact surface 7 for the packaged object. In this case, the packaged object contact surface 7 is generally formed as a band-shaped portion parallel to the ridge lines A, B, and C.
The ridge angle is inclined like the hypotenuse of a triangle having the ridge angle as the apex angle to provide a reinforcing effect. It has been confirmed that the one shown in A, B, and C, especially the one shown in Fig. C, is the most effective in suppressing cracking due to its structure. Furthermore, the one shown in Figure D is a modification of the example shown in A above, and has a common thin part, but in particular, a groove 9 is provided between the contact surface of the packaged object and the thin part. There is. In this case, since the groove is only on one side, it can be formed relatively easily. In addition, the one shown in Figure E has a more complicated form, and the object contact surface 10 extends from the top corner along the diagonal line of each surface in the one shown in Figures A to C. It plays the role of a rib in the cushioning packaging material and strengthens the stability of its form. In each of the above examples, only the corner portions are shown, but as described above, the configuration includes the corner portions even if the ridge parts are integrally provided. Furthermore, it goes without saying that the above examples are not restrictive, and various modifications are allowed as long as they do not depart from the purpose or gist. By the way, in each of the above examples, the width of the contact surface of the packaged object near the ridgeline does not require any particular restriction, but generally, in the case shown in Fig. 4, the wall thickness of the packaging material is t ₁ In this case, the width t ₂ of the contact surface is 3 mm<t ₂ <t ₁ and the difference t ₃ from the packaging material thickness t ₁ in the thin portion 8 is preferably about 0 to 0.3 t ₁ . Especially 4/
Exceeding 5t ₁ should be avoided as much as possible from the viewpoint of the yield strength of the packaging material. Thus, due to the formation of the thinning in the present invention as described above, even if the force that tries to push open the molded product during a drop impact as described above results in bending stress centered on the corner, the contact surface of the product is not affected. On the other hand, the force that tries to push open the molded body is absorbed by the thin wall surface of the molded body by thinning of the required spread, causing it to close inward through the rolling phenomenon, and thereby reducing the bending stress. can do. Furthermore, when there is meat stealing on all three sides, the propagation of stress is prevented by meat stealing on the other side, and these things work together to reduce the stress compared to the case of meat stealing on both sides according to the previous proposal. , it is possible to maintain a shape closer to that of partial simple compression, thereby significantly suppressing crack damage. Hereinafter, the cushioning packaging material of the present invention will be further described with respect to other packaging materials, namely, a corner patch made of a blank foamed resin molding having no flesh filtration (Comparison 1) and Utility Model Application No. 56-159780 previously proposed by the present applicant. The results of a drop test are shown with a corner putt (Comparison 2) in which groove-shaped thinning was provided on two sides and diagonal thinning was provided on the other side. In addition, the test was carried out using cargo weighing 10 kg as a product.
Each 110 x 110 x 110 mm corner piece with a wall thickness of 30 mm was placed in contact with each corner, covered with cardboard, and then dropped along the ridgeline as shown in Figure 2 to reach the limit of shock absorbing material cracking (scattering) due to one corner drop. Hawkness was measured.
The results were as follows.

[Table] In addition, when the height of each of the above-mentioned various cushioning materials was changed and the conditions were observed, the results were as follows.

[Table] From the above results, it is confirmed that the cushioning packaging material of the present invention has a significantly superior effect compared to other materials. (Effect of the invention) As described above, the cushioning packaging material of the present invention has a thin wall of the required width with a step on the inner surface of at least one of the three surfaces that intersect with each other, leaving a required width portion adjacent to the two ridges. As is clear from the results of the drop test mentioned above, when the packaging material falls from the edge,
Even if a force trying to push the molded body open is applied to the two approximately right-angled surfaces forming the ridge, the thin-walled side will conversely weaken the force trying to close it inward due to the rolling phenomenon. , to absorb this by making it smaller, and since the contact with the product body is limited to the parallel part of the required width, the contact between the shock absorber and the product body is reduced, the pressure receiving area is reduced, and the bending stress is weakened.
When a thermoplastic foamed resin molded product is dropped from the edge where the most damage occurs due to cracking, it is possible to not only suppress the damage caused by cracking of the packaging material due to the impact of the fall, but also to reduce stress dispersion. The effect of suppressing cracking is further ensured, and unlike lowering the foaming ratio or increasing the wall thickness of the molded product, the amount of foamed molding material used can be reduced. It is an extremely effective packaging material both economically and practically, since it does not increase the amount of material used and also saves the amount of material used.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of how the cushioning packaging material of the present invention is used, Fig. 2 is a sectional view showing a state in which a product packed with the packaging material falls from the edge, and Fig. 3 A to H show the cushioning material of the invention. FIG. 4 is an explanatory perspective view showing each embodiment of the packaging material, and FIG. 4 is an explanatory diagram showing the dimensional relationship of the cushioning packaging material of the present invention. 1... Item to be packaged, A, B, C... Ridge line, 2...
Cushioning packaging material, 2a, 2b, 2c... each side, 7, 1
0...Contact surface of packaged object, 8...Thin wall portion.

Claims (1)

[Claims for Utility Model Registration] 1. A packaging material that is made of a thermoplastic resin foam molding, has at least three mutually intersecting surfaces, and that partially or completely adheres to the outer surface of the packaged object during packaging. A thin wall with a required width and a step along two ridges formed by the intersection of one surface with the other adjacent surface, leaving a contact surface of the required width adjacent to the ridges. A cushioning packaging material characterized by being provided with a meat cover consisting of parts. 2. The shock-absorbing packaging material according to claim 1, wherein the thin-walled portion having a step is one surface and covers all parts except for the surface in contact with the packaged object near the ridge. 3. Utility model registration where the thin part with a step is the other part excluding the packaged object contact surface near the ridge and the packaged object contact surface extending diagonally from the ridge corner of the contact surface on the packaging material surface. A cushioning packaging material according to claim 1. 4. The step is provided at a portion of the packaging material that remains within t ₁ of the ridgeline on the side that contacts the packaged material, where t ₁ is the thickness of the packaging material, and that the depth is The cushioning packaging material according to any one of claims 1 to 3, which has a weight of 4/5t ₁ or less.