JP4316205B2 - Transportation spacer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transportation spacer, and more particularly, when a packaged product is stacked and loaded in a luggage compartment of a truck, the spacer is appropriately inserted between packaged bodies for the purpose of preventing collapse and buffering. It relates to a transportation spacer.
[0002]
[Prior art and problems]
2. Description of the Related Art Conventionally, for the purpose of preventing a package from collapsing when transporting by truck and as a cushioning material, a spacer for transportation is installed between the packages.
As this transport spacer, polystyrene foam is often used from the viewpoints of lightness, economy and buffer characteristics.
[0003]
However, this polystyrene foam is prone to cracking and chipping due to impact, etc. during use, and is difficult to use repeatedly, and there is also a concern that the generated debris and powder will adhere to the package and stain the package. It was.
[0004]
Therefore, a transport spacer having a structure in which the entire outer surface of the plate-like body made of polystyrene foam is covered with a heat-shrinkable synthetic resin film having a predetermined tensile strength or more can be considered. A secondary process of heat shrinking the film is required, resulting in a significant increase in cost. In addition to this cost increase, durability cannot be improved as much as the difference, and repeated use is limited.
[0005]
The present invention has been made in view of the problems of the above-described conventional technology, and its purpose is to provide a transport spacer that can sufficiently withstand repeated use and that is excellent in lightness, handleability, and buffer characteristics. The purpose is to do.
[0006]
[Means for Solving the Problems]
As a result of diligent research to achieve the above object, the present inventors have paid attention to a polyolefin resin foam excellent in flexibility, compressive strain recovery, and flexibility. The present invention was completed by finding that the above object can be achieved if the front plate has a predetermined plate thickness, density, flexural modulus, and compressive strain recovery, and a plate-shaped transport spacer as a whole. I let you.
[0007]
That is, the present invention is a transport spacer that is made of a polyolefin resin foam having a rectangular front shape and is entirely plate-shaped. The transport spacer is formed by molding a polyolefin resin foam bead by a cracking filling method. It consists of a bead foam molded body formed by filling the mold cavity and heating the foam beads to mold in the mold, and the plate thickness is 10 to 200 mm, the density is 10 to 90 g / L, and the flexural modulus is There 1,000～30,000KPa, and residual strain after 75% compression Ri der 25% or less, the entire surface of the carrying spacer is formed with a skin layer, the peripheral portion of the carrying spacer In the vicinity of the center of the arc-shaped peripheral edge portion in the plate thickness direction, the circumferential end of one molding die that defines the cavity extends along the inner surface of the circumferential end of the other molding die. That it has a step formed by fitting it was carrying a spacer, wherein.
[0008]
Here, in the transport spacer according to the present invention described above, the plate thickness is set to 10 to 200 mm. The transport spacer having a plate thickness of less than 10 mm has insufficient buffer characteristics and functions as a buffer material. On the contrary, when it exceeds 200 mm, the transport spacer itself occupies a lot of space, and the transport efficiency is deteriorated.
[0009]
Further, in the transport spacer according to the present invention described above, the density (apparent core density of JIS K 7222: 1999) is set to 10 to 90 g / L. If the density is less than 10 g / L, the buffer characteristics are still insufficient. In contrast, when the density exceeds 90 g / L, the carrying spacer becomes heavy and handling properties are deteriorated.
[0010]
Further, in the transport spacer according to the present invention described above, the flexural modulus is set to 1,000 to 30,000 KPa because the transport spacer having a flexural modulus of less than 1,000 KPa is not self-supporting and handled. On the other hand, when the transport spacer has a bending elastic modulus exceeding 30,000 KPa, it is difficult to be deformed, and there is a problem when the transport spacer is inserted into a gap between packages. Because.
[0011]
In the transport spacer according to the present invention described above, the residual strain after 75% compression is 25% or less when the transport spacer is repeatedly used with the residual strain after 75% compression exceeds 25%. This is because the buffer properties of the transport spacer cannot be expected.
[0012]
The transportation spacer comprising the polyolefin resin foam according to the present invention having the above-described physical properties is a transportation spacer that can sufficiently withstand repeated use and is excellent in lightness, handling properties, and buffer characteristics.
[0013]
Also, carrying spacer according to the present invention was formed by molding in a mold by heating the foamed beads expanded beads of a polyolefin resin is filled into the cavity of the mold by cracking filling method consists expanded bead molded article, said carrying spacers due to a structure having a skin layer on the entire surface, hardly smudges on the surface, also Ru Hakare improved strength.
[0014]
In addition, the transport spacer according to the present invention has a peripheral edge formed in a circular arc shape in the cross section, and a peripheral edge of one molding die that defines a cavity near the center of the arc-shaped peripheral edge in the plate thickness direction. Since there is a step formed by fitting the part along the inner surface of the peripheral end of the other molding die , the peripheral part is chamfered, there is no angular corner, and there is no chipping or cracking. together it becomes difficult to occur, small contact area with the floor surface or the like when the leaning, Ru which hardly stains and growth.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the transport spacer according to the present invention will be described in detail.
[0016]
As shown in FIG. 1, the transport spacer 1 according to the present invention has a front rectangular shape and is entirely made of a plate-like polyolefin resin foam.
[0017]
The polyolefin-based resin corresponds to any of the following (a) to (e).
(A) A homopolymer of an α-olefin such as ethylene, propylene, and butene.
(B) A copolymer of two or more α-olefins.
(C) a copolymer comprising an α-olefin component and another monomer component, and the α-olefin unit component ratio is 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more, More preferably 80% by weight or more, most preferably 90% by weight or more of the copolymer.
(D) A mixture of two or more selected from the group of (a), (b) and (c) above.
(E) one or more selected from the group (a), (b), (c) and (d) above, and (a), (b), (c) or (d) above Is a mixed resin composition with other different synthetic resin components or / and other synthetic elastomer components, wherein the α-olefin component unit ratio in the composition is 50% by weight or more, preferably 60% by weight or more The mixed resin composition is preferably 70% by weight or more, more preferably 80% by weight or more, and most preferably 90% by weight or more.
[0018]
The polyolefin resin foam forming the transport spacer 1 according to the present invention is preferably a polypropylene resin among the above polyolefin resins.
This is preferable because a material made of polypropylene resin is excellent in strength, and the same strength can be realized at a lighter weight than a material made of polyethylene resin, for example.
[0019]
The polypropylene resin corresponds to any of the following (f) to (i).
(F) A propylene homopolymer.
(G) A copolymer comprising a propylene component and another monomer component, and the proportion of the propylene unit component is 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more, and still more preferably 80%. % Or more, most preferably 90% or more by weight of copolymer.
(H) A mixture of two or more selected from the group of (f) and (g) above.
(I) One or more selected from the group of (f), (g) and (h) above, and another synthetic resin component different from the above (f), (g) or (h) or / And other synthetic elastomer components mixed resin composition, propylene component unit ratio in the composition is 50 wt% or more, preferably 60 wt% or more, more preferably 70 wt% or more, still more preferably 80% by weight or more, most preferably 90% by weight or more of a mixed resin composition.
[0020]
The polyethylene resin corresponds to any of the following (j) to (m).
(J) A homopolymer of ethylene.
(K) A copolymer comprising an ethylene component and another monomer component, and the ethylene unit component ratio is 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more, and still more preferably 80%. % Or more, most preferably 90% or more by weight of copolymer.
(L) A mixture of two or more selected from the group of (j) and (k) above.
(M) one or more selected from the group (j), (k) and (l) above, and other synthetic resin components different from the above (j), (k) or (l) or / And other synthetic elastomer component mixed resin composition, ethylene component unit ratio in the composition is 50 wt% or more, preferably 60 wt% or more, more preferably 70 wt% or more, still more preferably 80% by weight or more, most preferably 90% by weight or more of a mixed resin composition.
[0021]
Add necessary amounts of various additives such as antistatic agents, bubble regulators, flame retardants, flame retardant aids, inorganic fillers to the polyolefin resin constituting the polyolefin resin foam as required. Can do.
[0022]
The transportation spacer 1 according to the present invention uses the above polyolefin resin, preferably filled with foamed particles obtained by foaming the polyolefin resin into beads into a molding die, and heated to a predetermined temperature. Next, a bead foam molded body produced by a cooling method, that is, a so-called in-mold molding method is preferable.
This is because the foam foam molded body has no cutting or cutting surface on its surface, and becomes a transport spacer having a dense and smooth skin layer on the entire surface, so that the surface is difficult to get dirty and the strength is improved. It is preferable because it can be achieved.
[0023]
Moreover, although the dimension of the spacer 1 for conveyance which concerns on this invention, especially length and width are not specifically limited, It is normally 100-200 cm in height and 50-150 cm in width, and the Example goods shown in FIG. The length is 120 cm and the width is 90 cm.
Moreover, the plate | board thickness of the spacer 1 for conveyance which concerns on this invention is 10-200 mm from a viewpoint of a buffer characteristic and transport efficiency, Preferably it is set as the plate | board thickness of 20-100 mm, and the Example goods shown in FIG. It is said that the plate thickness.
[0024]
Further, as shown in an enlarged view in FIG. 2, the transport spacer 1 according to the present invention has a peripheral edge 2 formed in an arc shape in cross section, and a step 3 near the center of the arc-shaped peripheral edge in the thickness direction. Is formed.
This is because the peripheral edge is chamfered and has no angular corners, so that it becomes a transportation spacer that is less prone to chipping or cracking, and the contact area with the floor surface when the transportation spacer is stood Is preferable because it is small and resistant to contamination.
[0025]
Further, as shown in the front view shown in FIG. 1 and the cross-sectional view shown in FIG. 3, the transport spacer 1 according to the present invention has a large letter 5 “SAFETY FIRST” due to the unevenness on the front and back plate surfaces 4. It is displayed.
This is preferable because the design of the transport spacer is improved, the design can be distinguished from other products, and the transport spacer can be easily recognized.
[0026]
When the carrying spacer 1 having the arcuate peripheral edge as shown in FIG. 2 is manufactured by the above-described in-mold molding method, the molding die is shaped as shown in FIG. Cracking at the time of filling the foam beads [step of FIG. 4 (a) for slightly opening the mold and improving the fillability of the foam beads] causes burrs B on the mating surfaces of the mold. The appearance of the carrying spacer, which is a molded product, is poor [FIG. 4 (c)].
Therefore, if a molding die having a shape as shown in FIG. 5 is used, the above-mentioned preferable form in which the stepped portion 3 is formed in the vicinity of the center of the arc-shaped peripheral portion in the thickness direction of the arc-shaped peripheral portion. The carrying spacer 1 can be formed, and this carrying spacer exhibits a good appearance with no occurrence of burrs [FIG. 5 (c)].
[0027]
The density of the transport spacer 1 according to the present invention comprising the polyolefin resin foam exhibiting the above-described external shape is adjusted from the viewpoint of buffer characteristics, lightness and handling by adjusting the expansion ratio of the polyolefin resin foam. , 10 to 90 g / L, preferably 20 to 50 g / L.
[0028]
In addition, the bending elastic modulus of the transport spacer 1 according to the present invention is 1,000 KPa or more in order to ensure the minimum necessary independence in handling, and the buffering action due to deformation and the insertion work into the gap From the viewpoint of property and the like, it should be 30,000 KPa or less. In addition, Preferably it is a spacer for conveyance of the bending elastic modulus of 1,200-25,000KPa.
In addition, the bending elastic modulus of the said spacer for conveyance is the value measured based on JISK7222-1: 1999. However, a test piece having a thickness of 5 mm without skin is used, and the number of test pieces is five.
[0029]
Further, the transport spacer 1 according to the present invention has a residual strain after 75% compression of 25% or less.
This is because a carrier spacer having a residual strain after 75% compression exceeding 25% cannot be expected to maintain the buffer characteristics of the carrier spacer when repeatedly used.
The residual strain after 75% compression referred to in the present invention is a value measured as follows.
First, a test piece without a skin having a length of 50 mm, a width of 50 mm, and a thickness of 25 mm (overlap when the thickness is 25 mm or less) is cut out from the transport spacer.
Next, this test piece is subjected to a static compression test in accordance with method A of JIS Z 0234-1976. The test conditions at this time are as follows.
The specimen is compressed (75% compression) at a rate of 10 ± 1 mm / min in the thickness direction of the specimen until it reaches 25% of the original specimen thickness (T ₀ : mm), and then immediately opposite to the direction of compression. The compression is released at a speed of 10 ± 1 mm / min. Immediately after release, the thickness of the test piece is measured, and this is defined as T ₁ (mm). The number of test pieces in this test is 5.
Based on the above measurement, the residual strain (S:%) after 75% compression for each specimen is obtained by the following equation.
S = (T ₀ −T ₁ ) × 100 ÷ T ₀
The residual strain after 75% compression referred to in the present invention refers to a value obtained by arithmetically averaging a total of five results of residual strain after 75% compression for each test piece.
[0030]
The transportation spacer 1 comprising the polyolefin resin foam according to the present invention having the above physical properties is a transportation spacer that can sufficiently withstand repeated use and has excellent lightness, handling properties, and buffering properties. As shown in Fig. 5, when the packed product A is stacked and loaded on the pallet P in the luggage compartment of the truck T, the packing A is properly disposed between the packing bodies A and A for the purpose of preventing the collapse of the cargo and buffering. And used in the space between the track T and the track T.
In addition, as a polyolefin-type resin foam provided with the bending elastic modulus of the above-mentioned range and the residual strain of the above-mentioned range, the density is a product name "P-Block" which is a polypropylene resin foam of JSP Corporation. Examples include those having a density of 15 to 80 g / L, among those having a density of 10 to 90 g / L, and the product name “L-Block” which is a polyethylene resin foam of the company.
[0031]
【The invention's effect】
As described above, according to the transportation spacer according to the present invention described above, there is an effect that the transportation spacer can sufficiently withstand repeated use and is excellent in lightness, handling properties, and buffer characteristics.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a view showing a transport spacer according to the present invention, in which (a) is a front view, (b) is a right side view, and (c) is a bottom view.
FIG. 2 is an enlarged cross-sectional view of a portion along the line XX in FIG.
FIG. 3 is a cross-sectional view of a portion along line YY in FIG.
FIG. 4 is a diagram conceptually showing an unfavorable shape of a molding die in the case of manufacturing a transport spacer according to the present invention by an in-mold molding method, and (a) is a state of filling a raw material (when cracking) FIG. 5 is a cross-sectional view showing the material, (b) a cross-sectional view showing the raw material at the time of heat forming, and (c) a side view showing the resulting transport spacer.
FIG. 5 is a view conceptually showing a preferable shape of a molding die in the case where the carrying spacer according to the present invention is manufactured by an in-mold molding method, and (a) shows a state when a raw material is filled (cracking). It is sectional drawing shown, (b) Sectional drawing which showed the time of thermoforming of a raw material, (c) Side view which showed the obtained spacer for conveyance.
FIG. 6 is a diagram conceptually showing a use state of the transport spacer according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Spacer for conveyance 2 Peripheral part 3 Level difference 4 Board surface 5 Character T Track A Packing body B Burr P Pallet

Claims (2)

A transportation spacer having a rectangular front shape and made of a polyolefin resin foam having a plate shape as a whole. The transportation spacer is formed by a method in which foam beads of polyolefin resin are placed in a cavity of a molding die by a cracking filling method. It consists of a bead foam molded body formed by filling and heating the foam beads to mold them in-mold, with a plate thickness of 10-200 mm, a density of 10-90 g / L, and a flexural modulus of 1,000-30. , 000KPa, and residual strain after 75% compression Ri der 25% or less, the entire surface of the carrying spacer is formed with a skin layer, the peripheral portion of the carrying spacer is formed in an arc-shaped cross section In addition, the peripheral end portion of one molding die that defines the cavity is fitted along the inner surface of the peripheral end portion of the other molding die in the vicinity of the center in the plate thickness direction of the arc-shaped peripheral edge portion. Characterized in that it has a more formed step, carrying a spacer. The peripheral edge of the transport spacer includes an arc that defines a peripheral edge from one plate surface to the vicinity of the center in the thickness direction, and an arc that defines a peripheral edge from the other plate surface to the vicinity of the center in the thickness direction. The transport spacer according to claim 1, wherein the step is formed so as to be shifted in a direction perpendicular to the plate thickness direction, and the arcs shifted are connected to each other .

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