JP4403207B2 - Buffer packaging material - Google Patents

Description

  The present invention relates to a shock-absorbing packaging material, and more particularly to a shock-absorbing packaging material provided with a protrusion having shock absorbing properties.

  Conventionally, when packaging precision equipment such as home appliances and IT-related products in a cardboard box or the like and transporting them, a buffer wrapping material has been used to protect the products from vibrations and impacts caused by dropping. The buffer wrapping material plays a role of fixing the product in the cardboard box and absorbing an impact from the outside. Conventionally, corner pads and side pads made of foamed polystyrene or foamed polyolefin are used as such cushioning packaging materials, and these cushioning packaging materials are provided with ribs of various shapes in order to improve the cushioning performance.

  However, although the impact resistance of the product itself has been improved by reducing the weight of various precision instruments in recent years, buffer packaging materials have been required to have higher buffer performance than before, and the conventional ribs have been required. The shape of the cushion packaging material can no longer meet the demand.

  Under such circumstances, there is one disclosed in Japanese Patent Application Laid-Open No. 2003-341742 (Patent Document 1) as a cushioning packaging material having a high cushioning performance that has not been obtained conventionally. In the buffer packaging material of Patent Document 1, as shown in FIG. 3, a protruding portion 21 that absorbs stress from the outside of the buffer packaging material is provided, and the shape of the protruding portion 21 is the size of the cross-sectional area orthogonal to the stress. Is repeated twice or more continuously or stepwise.

  However, the cushioning performance of the protrusion of the cushioning packaging material of Patent Document 1 is insufficient, and the impact cannot be absorbed sufficiently. Specifically, when an impact is applied from the protruding direction of the protruding portion, the shock absorbing performance does not work at all, and it is impossible to prevent destruction of the accommodated item. It was barely possible to protect the packaged item when the tip of the protrusion and the wall surface of the cardboard box slipped, the protrusion fell to the side, and the entire side surface of the protrusion received an impact. However, in this case, even though it was possible to prevent destruction of the packaged item, the stepped constricted portion was easily broken, and after it broke, it no longer functioned as a cushioning packaging material.

JP 2003-341742 A

  An object of the present invention is to provide a shock-absorbing packaging material that is excellent in shock absorbing performance, and that does not break a protrusion even after absorbing an impact, and that can reduce the cost of physical quantity.

According to the present invention, the following buffer packaging material is provided.
[1] In a shock-absorbing wrapping material that has at least a holding portion of a stored item and a plurality of protrusions that absorb external stress, and can be stored in a storage box while holding the stored item,
Together with the shape of the protrusions is a rectangular parallelepiped, the protrusions, have a four through holes in the direction perpendicular to the direction of projection from the holding portion, the protruding portion the four through-holes are rectangular The planes having the largest area are connected to each other, and each through hole is located on each of the four straight lines connecting the center of the plane having the largest area and the midpoint of each side of the plane. Characteristic cushioning packaging material.
[2] The cushioning packaging material according to [1], wherein the space volume of the through hole is 10 to 60% with respect to the volume of the protrusion 100%.
[3 ] The cushioning packaging material according to [1] or [2] , wherein the cushioning packaging material is formed of a foamed polyolefin-based resin-molded particle.

  The shock-absorbing packaging material of the present invention is excellent in shock absorbing performance, and the protrusions are not destroyed even after absorbing the shock. In addition, since the shock absorbing property of the protruding portion is excellent, the length of the protruding portion can be shortened and the volume of the box can be reduced, so that the distribution cost can be reduced.

Hereinafter, the buffer packaging material of this invention is demonstrated in detail based on FIG. 1, FIG. However, the present invention is not limited to FIGS.
As shown in FIG. 1, the shock-absorbing packaging material of the present invention has at least a holding part 2 for stored items and a protruding part 3 that absorbs external stress. The holding unit 2 has a function of holding a stored item (not shown) such as a precision instrument. Specifically, a concave portion 5 is formed in the holding portion 2, and a part of the accommodated product is inserted and fitted into the concave portion 5 to fix and hold the accommodated product.

The protrusion 3 has four through holes 6 in a direction perpendicular to a direction protruding outward from the holding portion 2 (hereinafter also simply referred to as a protrusion direction). That is, the projection 3 of the present invention is provided with four through holes 6 in a direction orthogonal to a direction (projection direction) in which an impact load is applied to the accommodated product. In other words, as shown in FIG. 2, the protruding portion 3 includes a bone portion 7 and has a skeletal structure having a space (through hole 6) therein. When an impact load is applied to the protrusion 3 having such a structure, the bone 7 is crushed and the impact is easily absorbed. As a result, since no large G value is applied to the stored product, the stored product is prevented from being damaged.
In addition, a protrusion direction means the direction which tied the shortest distance of the front-end | tip of the protrusion part 3 which contacts a storage box from the boundary of the protrusion part 3 and the holding | maintenance part 2 with the straight line. The direction perpendicular to the projection direction is not only the direction in which the center line of the through-hole is completely perpendicular to the projection direction, but also absorbs the impact by collapsing the bone when an impact load is applied. If possible, it means that the center line of the through hole includes a direction inclined with respect to the protrusion direction.

Moreover, since the through-hole 6 of the projection part 3 is provided in the part with the largest area when the projection part 3 is seen in planar view, it is excellent in shock absorption.

  Although there is no restriction | limiting in the shape of the whole protrusion part, Since manufacture is easy and it is easy to handle, a rectangular parallelepiped is preferable normally.

  The shock-absorbing packaging material of the present invention is accommodated in a storage box in a state where a stored product is held. Therefore, it is preferable that a flat portion 9 is provided at the tip of the protrusion 3 as shown in FIGS. If the flat portion 9 is provided, the cushioning packaging material in which the packaged items are packaged can be easily stored in the storage box (usually a cardboard box) and stably supported in the storage box. Can do.

  The length of the protrusion 3 in the protrusion direction is usually preferably 40 to 250 mm, although it depends on the weight of the accommodated item, the allowable G value, the position in the protrusion direction, and the like. If the length is short, there is a risk of damage to the container. In this respect, 50 mm or more is more preferable, and 60 mm or more is further preferable. On the other hand, if the length is too long, the volume in the storage box increases, and the transport efficiency may be reduced. From this viewpoint, 230 mm or less is more preferable, and 210 mm or less is more preferable.

  The space volume of the through hole 6 is preferably 10 to 60% with respect to 100% of the volume of the protrusion 3. When the space volume of the through hole is less than 10% of the volume of the projection, the projection is not easily crushed, so that there is a possibility that the impact load cannot be sufficiently absorbed. In this respect, 20% or more is more preferable, and 30% or more is still more preferable. On the other hand, when it exceeds 60%, there is a possibility that the protrusion 3 is too weak to sufficiently absorb the impact load. In this respect, 55% or less is more preferable, and 45% or less is still more preferable.

In the present invention, the measurement of the volume of the protrusion 3 and the spatial volume of the through hole 6 is performed as follows.
First, the volume of the protrusion 3 is measured. When the shape of the protrusion 3 is simple, the space volume (C: cm ³ ) of the protrusion 3 is obtained by multiplying the cross-sectional area (including the cross-sectional area of the through-hole 6) by the height. In this case, the boundary between the protruding portion 3 and the holding portion 2 is determined by extending a straight line constituting the holding portion 2 in plan view. When the shape of the protrusion 3 is complicated and cannot be obtained by calculation, the protrusion 3 is cut out, the cut protrusion 3 is submerged, and the increase is defined as a volume (A: cm ³ ), and this volume (A : Cm ³ ) and the spatial volume (B: cm ³ ) of the through-hole 6 described later are defined as the spatial volume (C: cm ³ ) of the protrusion 3. In addition, when cutting out the projection part 3, it cuts out so that the straight line which comprises the holding | maintenance part 2 may be extended in planar view. In this case, even if the protruding portion 3 is removed, the holding portion 2 is cut so that the function and appearance are not extremely deteriorated. Specifically, the protruding portion 3 and the holding portion 2 are cut out from the portion indicated by the dotted line in FIG. The cut protrusion 3 is submerged, and the increase is defined as the volume (A: cm ³ ). This volume (A: cm ³ ) is the volume of the protrusion 3 that does not include the space volume of the through hole 6.
Next, the spatial volume (B: cm ³ ) of the through hole 6 is measured. When the shape of the through-hole 6 is simple, the space volume (B: cm ³ ) of the through-hole 6 is obtained by multiplying the cross-sectional area and the depth. If the shape of the through-hole 6 is complicated and cannot be obtained by calculation, one of the through-holes 6 is closed and filled with sand, and then the sand is placed in a measuring cylinder and the scale is measured. And the space volume of the through hole 6 (B: cm ³ )

The volume 100% of the protrusion 3 referred to in this specification means the spatial volume (C: cm ³ ), or the volume (A: cm ³ ) of the protrusion 3 that does not include the spatial volume of the through hole 6 and the through hole 6. This means the total volume (A + B: cm ³ ) with the spatial volume (B: cm ³ ), and the spatial volume of the through hole 6 with respect to 100% of the volume of the protrusion 3 is {B / C} × 100 (% ), Or {B / (A + B)} × 100 (%).
In the case of the dotted line α in FIG. 1, the space volume of the through hole 6 partially overlaps the holding portion 2, but the space volume (C: cm ³ ) or the protrusion 3 is cut out and the volume (A: cm ³ ) is measured.

The number of through holes 6 is rather limited in the number be at least 4, excellent impact absorption when dropped by this. On the other hand, the upper limit is preferably 10 or less, more preferably 8 or less, because the protrusion is broken and is difficult to separate from the holding part in the event of a drop impact. The shape of the through hole 6 is not limited, and the shape of the cross section can be a circle, ellipse, triangle, rectangle, heart shape, spade shape, gourd shape, cross shape, etc. You can also

Moreover, in this invention, the protrusion part 3 of a different structure can be provided in one buffer packaging material. For example, in the aspect shown in FIG. 1, the protrusion part 3a which has four through-holes, and the protrusion part 3b which has two through-holes are provided.
The shock-absorbing packaging material of the present invention may be provided with a projection 11 (hereinafter also referred to as “rib”) having no normal through-hole. For example, in the aspect of FIG. 1, the part shown with the code | symbol 11 corresponds to it.

In the present invention, the protrusion 3 having the four through holes 6 in the direction orthogonal to the protrusion direction outward from the holding part 2 is a holding part that accommodates an up and down direction, that is, a container. 2 is preferably provided above or below, and more preferably above and below. Such a configuration is preferable because it efficiently absorbs an impact.
Further, the projection direction of the projection 3 may be any angle with respect to the surface of the storage box, but it is preferable that the projection direction is orthogonal to the surface of the storage box in order to efficiently absorb the impact.

Next, a preferable example of the aspect of the protrusion will be described with reference to FIGS.
In the shock-absorbing packaging material of the present invention, as shown in FIG. 2, the shape of the protrusion 3 is a rectangular parallelepiped, and four through holes 6 are provided to connect the planes 10 having the largest area of the rectangular parallelepiped. but most middle of center a and each side of the plane of the wide area plane 10 B, C, D, are positioned on each of the four straight lines connecting the E. In other words, the protruding portion 3 has four through holes 6, the flat portion 9 has two wall portions 7 a facing the protruding direction, and the four wall portions 7 b separating the through holes 6, and the two wall portions 7b is extend from the rectangular center in a plan view across the direction of the flat portion 9, that has grown from the rectangular center the other two walls 7b is a plan view across the direction of the coupling portion of the protrusion 3 and the retaining part 2 .

If comprised in this way, the impact load concerning the flat part 9 will be spread and applied to the wall part 7a and the wall part 7b, and an impact will be effectively carried out by compressing the wall part 7a and the wall part 7b. Absorbed.
In this case, since the impact load is mainly applied to the wall portion 7a, the wall portion 7a may be broken. However, even in that case, the wall 7b serves as a reinforcing material, so that the projection 3 is not destroyed as a whole, and the buffer performance is not completely lost.

Although there is no restriction | limiting in the raw material of the buffer packaging material of this invention, A pulp mold and a synthetic resin foam are illustrated. Among these, a synthetic resin foam having low hygroscopicity and excellent shock absorption is preferable.
Examples of the base resin of the synthetic resin foam include styrene resins such as impact-resistant polystyrene (HIPS) and polystyrene, polyolefin resins such as polyethylene resins and polypropylene resins, polymethyl methacrylate, and polyacrylate. Poly (meth) acrylic resins, polycarbonate resins, aromatic polyester resins such as polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate, polyamide resins such as nylon-6 and nylon-6,6, polyphenylene ether resins, poly Examples thereof include one or a mixture of two or more of biodegradable resins such as butylene succinate, polybutylene adipate, polybutylene succinate adipate, and polylactic acid resin. Among these, polyolefin resins are preferable because they are excellent in flexibility and durability, are easy to manufacture and are inexpensive.

  As the polyolefin resin, a resin containing an olefin component in a proportion of 50 mol% or more is preferable. For example, a low density polyethylene, a high density polyethylene resin, a linear low density polyethylene, an ethylene-butene block copolymer, Ethylene ionomer resin and polypropylene resin in which ethylene-butene random copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-methacrylic acid copolymer molecules are cross-linked with metal ions Can be mentioned. Among these, polypropylene resins are preferable because they are excellent in flexibility, durability, and heat resistance, are easy to manufacture and are inexpensive. Examples of the polypropylene resin include propylene homopolymer, propylene-ethylene copolymer, propylene-butene copolymer, polybutene, polypentene, propylene-ethylene-butene terpolymer, propylene-acrylic acid copolymer, and Examples include propylene-maleic anhydride copolymer. Further, a graft-modified polyolefin resin obtained by impregnating the polyolefin resin with a vinyl monomer such as styrene and graft polymerization can also be used.

Furthermore, since the holding part and the protrusion part can be molded integrally, and even if it has a complicated shape, it can be easily molded. Is preferably used. Among them, a polyolefin resin-in-mold foamed particle molded body is preferable from the viewpoint of flexibility such that the protrusion is not easily broken when subjected to an impact. Furthermore, a polypropylene-based resin-molded expanded particle molded body is preferable because it is excellent in flexibility, durability, and heat resistance, is easy to manufacture, and is inexpensive. In addition, since the through-hole 6 of the projection part 3 can be easily formed in a direction parallel to the opening / closing direction of the mold in the mold, it is preferable.
However, in the present invention, the separately produced holding portion 2 and the protruding portion 3 may be combined.

In the case of an in-mold expanded particle molded body, the apparent density is determined according to the accommodated item and the target G value. From the viewpoint of excellent buffering properties, 0.015-0.07 g / cm ³ is preferable, 0.017-0.06 g / cm ³ is more preferable, and 0.02-0.05 g / cm ³ is more preferable. The apparent density is obtained by dividing (WM / VM) the weight WM (g) of the in-mold expanded particle molded body by the volume VM (cm ³ ) determined from the outer dimensions of the in-mold expanded particle molded body.
The G value is the maximum value of acceleration that can be sustained without damaging the article physically or functionally, and the drop condition changes depending on the weight of the contained item, and the allowable G value also changes.

  Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1
A shock-absorbing packaging material having the form shown in FIG. 1 was produced using a polypropylene resin-molded in-mold expanded particle molded product having an apparent density of 0.02 g / cm ³ (trade name “P-Block” manufactured by GS Corporation). The cushion packaging material has a protrusion 3a and a protrusion 3b. The protrusion 3a has a length of 100 mm, and the volume ratio of the through hole 6 is 30% with respect to the volume of 100%. The length is 50 mm, and the ratio of the space volume of the through hole 6 to the volume of 100% is 28%. Moreover, the length of the flat part of the upper protrusion part and the flat part of the lower protrusion part is 300 mm.
Using the buffer packaging material, a precision machine having a weight of about 2.7 kg is held and stored in a cardboard box (size 497 mm × 492 mm × 300 mm), covered with gummed tape, and the top surface of the cardboard box is A drop test from a height of 920 mm was performed according to JIS Z0202 (1994) with the bottom surface as the bottom surface.
The free fall test apparatus used was NEC Sanei's product name OMNIACE format RT3424ST, and the acceleration converter was MINEBEA CO. , LTD (filter 100 Hz) type BAH-200G, a sensor connected to an acceleration converter was attached to a precision machine as a stored product and measured. The results are shown in Table 1.

Comparative Example 1
A buffer packaging material was produced in the same manner as in Example 1 except that the buffer packaging material of the aspect shown in FIG. 3 was produced, and a drop test was performed. The results are shown in Table 1. The length of the protrusion 21 is 100 mm, the length of the protrusion 22 is 40 mm, the length of the flat portion of the upper protrusion and the flat portion of the lower protrusion is 300 mm, and the weight is about 2.7 kg. While holding the precision machine, it was stored in a cardboard box (size 497 mm × 492 mm × 300 mm).

The evaluation in Table 1 was performed according to the following criteria.
○ ・ ・ ・ G value less than 27 △ ・ ・ ・ G value 27 or more and less than 37 × ・ ・ ・ G value 37 or more

  The shock-absorbing packaging material of Example 1 did not damage the contained items, and the precision machine moved normally. In the shock-absorbing packaging material of Comparative Example 1, it is considered that the protrusion 3 could not absorb the impact, and when dropped, the impact was directly transmitted to the stored item and was damaged.

  From Table 1, it was found that the cushioning performance of the cushioning packaging material of the present invention is excellent, and the length of the protruding portion 3a can be shortened depending on the accommodated item.

(A) is a top view of the buffer packaging material of this invention. (B) is sectional drawing which follows the II line | wire of (a). (C) is a left side view. (A) is an enlarged plan view of the protrusion part 3a in FIG. (B) is an enlarged left side view. (A) is a top view of the conventional buffer packaging material. (B) is a front view. (C) is a left side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Buffer packaging material 2 Holding | maintenance part 3a Protrusion part 3b Protrusion part 5 Recessed part 6 Through-hole 7a Wall part 7b Wall part 9 Flat part 10 Flat surface 11 with the largest area 11 Rib

Claims (3)

In the shock-absorbing packaging material that has at least a holding portion of the stored item and a plurality of protrusions that absorb external stress, and can be stored in the storage box in a state of holding the stored item,
Together with the shape of the protrusions is a rectangular parallelepiped, the protrusions, have a four through holes in the direction perpendicular to the direction of projection from the holding portion, the protruding portion the four through-holes are rectangular The planes having the largest area are connected to each other, and each through hole is located on each of the four straight lines connecting the center of the plane having the largest area and the midpoint of each side of the plane. Characteristic cushioning packaging material.   The buffer packaging material according to claim 1, wherein the space volume of the through hole is 10 to 60% with respect to the volume of the protrusion 100%. The shock-absorbing packaging material according to claim 1 or 2 , wherein the shock-absorbing packaging material is formed of a polyolefin resin-molded in-mold foam particle molded body.

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