JPH0544280Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to a sheet pallet, and more particularly to a sheet pallet that can be suitably used when transporting goods by a so-called push-wheel forklift. [Prior Art] Various products packed in boxes or bags are placed on a stand and transported by a so-called push-up forklift equipped with a member called a platen. The platform on which these boxed (bagged) products are placed is generally called a pallet and is sheet-like. It is equipped with a gripping part called a tab or an ear part. An example of a cargo transport method using a forklift using this pallet is to hold the pallet's tension tabs to support the cargo, insert the platen under the pallet on which the cargo is placed, hold the entire pallet together, and lift the forklift. This is an operation in which cargo is carried by a lift and the cargo and pallets are unloaded from a platen, or the pallet is then pulled out by gripping the tabs, and is commonly performed in warehouses, for example. The sheet pallets used in such work have conventionally been made of paper, but this has had problems with its strength, such as the tension tabs tearing off. Therefore, sheet pallets made of thermoplastic resin have come into general use. This thermoplastic resin sheet pallet is lightweight, simple, thin, inexpensive, and has sufficient strength. Many inventions and ideas have already been made regarding this thermoplastic resin sheet pallet. For example, Japanese Utility Model Publication No. 55-16821 and Japanese Utility Model Application Publication No. 58-38516 disclose a method in which the surface of a sheet pallet is provided with irregularities or protrusions to prevent slipping of the loaded material. However, the conventional sheet pallets as described above are not always satisfactory due to the following problems. () When a sheet pallet with unevenness on both sides is placed on a sheet palletizer machine,
The load of the sheet pallets themselves causes the pallets to engage with each other at their uneven portions, making it difficult to separate them one by one, and thus making them difficult to use. () With sheet pallets that have mechanically or physically irregularities or protrusions on the surface, the irregularities are large, so when the sheet pallet is pulled out, these irregularities can cause pinholes to form in laminated bags, etc., or prints on the surface of the loaded cargo. If the printing (particularly on packages using printed polyethylene bags, such as fertilizer bags, etc.) is peeling off or is severely damaged, tear the bag. [Problems to be Solved by the Invention] The object of the present invention is to provide a sheet pallet that eliminates the drawbacks of the conventional examples as described above. [Means for solving the problem] The sheet pallet of the present invention is made of thermoplastic resin, and in order to solve the above-mentioned problem, the sheet pallet has a 10-point average roughness on the load loading surface and the non-loading surface.
It is characterized by providing unevenness of 20μ or more and less than 80μ, and furthermore, the size of the unevenness is different between the cargo loading surface and the non-loading surface so that they do not interlock with each other. As a result, the sheet pallet of the present invention has the feature that the sheet pallets can be easily separated without interlocking with each other due to unevenness. Examples of thermoplastic resins used in the sheet pallets of the present invention include olefin polymers, and specific examples include monopolymers of propylene, propylene and ethylene, or other α-olefins containing at most 12 carbon atoms. Propylene-based copolymers such as random or block copolymers with ethylene, homopolymers of ethylene, copolymers of ethylene and propylene or copolymers with α-olefins having at most 12 carbon atoms, etc. Examples include ethylene copolymers and compositions that are blends of these copolymers. When these polymers are propylene polymers or propylene copolymers, those with a melt flow index of 0.01 to 30 g/10 min are particularly preferred.
0.02 to 10 g/10 minutes is suitable. If a polymer with a melt flow index of less than 0.01 g/10 minutes is used, moldability will be poor. Moreover, if the polymer weight exceeds 30 g/10 minutes, the mechanical properties of the resulting molded product will deteriorate, which is not preferable. Furthermore, if the polymer is an ethylene polymer or an ethylene copolymer, its melt index is
0.01~30g/10 min is preferable, especially 0.02~
10 g/10 minutes is suitable. If a polymer with a melt index of less than 0.01 g/10 minutes is used, moldability will be poor, and if a polymer with a melt index of more than 30 g/10 minutes is used, the resulting molded product will have poor mechanical properties. The sheet pallet of the present invention is a sheet-like sheet made of thermoplastic resin as described above, and has unevenness on both sides (loading surface and non-loading surface), and the unevenness has a 10-point average roughness of 20 μm as described above. ~80μ. When the average roughness of these unevenness exceeds 80μ, when sheet saving is performed on a polyethylene bag, etc., the printing on the bag may peel off due to the protrusions on the sheet pallet, or pinholes may sometimes appear on the bag. I can not use it. Furthermore, if the average roughness is less than 20μ, when the sheet pallets are run on a palletizer for sheet pallets, the sheet pallets will stick together too closely and it will be difficult to separate them one by one. In the sheet pallet of the present invention, the depth of the grains (irregularities) is within the above-mentioned range, and the grains on the load loading surface and the non-loading surface have different shapes so that they do not mesh with each other. For example, as shown in FIG. 1, the shapes and sizes of the grains 1a and 1b on the loading surface and non-loading surface of the sheet pallet 1 are different. In other words, the two sides do not interlock as shown in the drawing. In addition, in the sheet pallet of the present invention, the coefficient of static friction against heavy kraft paper or polyethylene film (sheet) on the cargo loading surface and the non-loading surface is 0.2.
It is preferable that it is 0.5 or less. If the coefficient of static friction on the cargo loading surface exceeds 0.50, the sheet pallet will not slip easily between the sheet pallet and various types of cargo, such as paper bags made of kraft paper, fertilizer bags, polyethylene bags, cardboard boxes, etc., and it will be difficult to pull out the sheet pallet. or become impossible. Also, the coefficient of static friction
If it is less than 0.20, it is undesirable because it is likely to cause the load to shift during transportation with a forklift loaded with various types of cargo such as the above-mentioned paper, fertilizer bags, and cardboard boxes.
If the coefficient of static friction on the non-loading surface exceeds 0.5, the slippage between the sheet pallet and various items already placed on the ground, such as paper bags made of kraft paper, polyethylene bags such as fertilizer bags, and cardboard boxes, will worsen. However, it becomes difficult to pull out only the sheet pallet from between the upper and lower loads. Also, the coefficient of static friction is 0.20
If the amount is less than 1, the sheet pallet loaded with fertilizer bags etc. is placed on top of the cargo already placed on the ground in two tiers.
When stacked in three tiers, the items on the non-loading surface and the lower tier tend to slip and fall apart. Furthermore, in the sheet pallet of the present invention, if the difference in the coefficient of static friction between the cargo loading surface and the non-loading surface against heavy bag kraft paper is less than 0.1, sheets can be saved even if the front and back surfaces of the sheet pallet are used incorrectly. This is desirable because it is possible. The difference is
If the value is 0.1 or more and it is used incorrectly, it will be difficult to save the sheet and the baggage will have to be reloaded by hand, which is undesirable. Further, it is preferable that the uneven shapes of the cargo loading surface and the non-loading surface have no directionality with respect to the direction perpendicular to the tab portion and the direction parallel to the tab portion. For example, if the uneven shape has directionality as in the case of Utility Model Application No. 55-18452 and Utility Model Application No. 58-38516,
When a loaded object is moved by a forklift, etc., the object tends to collapse in the direction in which the uneven shapes are lined up. Furthermore, it is important that the tips of the convex portions of the concavo-convex shapes on the load loading surface and the non-loading surface be flat or rounded as shown in FIG. If the tip of the convex part mentioned above is sharpened, the suitability for palletizer machines will be greatly improved, but pinholes will occur in the bag when the sheet is saved, and the printing on the surface of the loaded object will peel off, or in severe cases, the bag will break. The thickness of the sheet pallet of the present invention described above is, for example, 0.5 mm to 5 mm. In addition, pigments, stabilizers, weathering agents, etc. can be added to the thermoplastic resin used in the sheet pallet of the present invention within a range that does not impair its functions.
For purposes such as improving rigidity, what is commonly called a filler may be added. This filler is
In general, those commonly used in the fields of synthetic resins and rubber may be used. These fillers do not react or react poorly with oxygen and water,
Those that do not decompose during kneading and molding are preferred. Specifically, metals such as aluminum, copper, iron, lead, nickel, oxides of these metals, magnesium, barium, zinc, zirconium, molybdenum, silicon, antimony, titanium, etc., their hydroxides, sulfates, Compounds such as carbonates, silicates, their double salts as well as mixtures thereof are conceivable. Among the fillers mentioned above, those in powder form preferably have an average particle size of 30 μm or less (preferably 10 μm or less). In addition, in the case of fibrous materials, the diameter is 1~
It is desirable to have a diameter of 500μ and a length of 6mm or less. Furthermore, in the case of flat particles, those with an average particle size of 30 μm or less are preferable. Among the above-mentioned fillers, flat (flake-like) fillers and powder-like fillers are particularly suitable. [Example] Next, an example of the sheet pallet of the present invention will be described based on the drawings. FIGS. 2 and 3 each show an embodiment of the sheet pallet of the present invention, in which the sheet pallet 1 is in the form of a sheet with an appropriate thickness as a whole, and includes a loading section 2 for loading cargo, and a loading section 2 for loading cargo. It is provided with a gripping part 3 which is held by a gripper of a forklift which is bent upward with respect to the mounting part 2. The sheet pallets of these examples are made of thermoplastic resin such as a propylene (co)polymer or a propylene (co)polymer composition, or an ethylene (co)polymer or an ethylene (co)polymer composition. Then, irregularities are provided on both sides by means as described below. Of these, the cargo loading surface has a 10-point average roughness of 40μ, and the non-loading surface has a 10-point average roughness of 80μ, and both have different shapes and sizes. On the other hand, the 10-point average roughness was measured using a universal surface profile measuring instrument (SE-3C) manufactured by Kosaka Institute, and the average roughness was measured using a JIS-
Based on BO601-1982, 10-point average roughness was used. The formation of the unevenness in the above embodiment is achieved by using a wrinkle roll for at least two of the cooling rolls used during sheet forming to obtain a sheet pallet having wrinkles (irregularities) on both sides during the sheet production process. I can do it. FIGS. 5 and 6 are diagrams showing an example of the arrangement of grain rolls during sheet forming. In these figures, 10 is a sheet forming die, 11 is a graining roll for the non-loading surface, and 12 is a graining roll for the cargo loading surface. Among these examples, in the one shown in FIG.
At the same time, wrinkles are formed on the loading surface. In the case shown in FIG. 6, wrinkles are first formed on the non-loading surface by a graining roll 11, and then grains are formed on the loading surface by a graining roll 12, thereby forming a sheet 14 for a sheet pallet. The cross-sectional shapes of the non-loading surface graining roll 11 and the loading surface graining roll 12 used here are as shown enlarged in FIG. 7 and FIG. 8, respectively. As shown in these figures, the graining roll for the non-loading surface has a graining depth of 50 μm, and the graining roll for the loading surface has a graining depth of 95 μm, and these shapes do not fit into each other. The sheet pallet of this embodiment has a static friction coefficient of 0.40 on the cargo loading surface and 0.32 on the non-loading surface with respect to the heavy bag kraft paper. Also, the static friction coefficient of the cargo loading surface in this example is
0.40, and the static friction coefficient of the non-loaded surface is 0.32, and the difference is 0.08. FIG. 9 shows an example of how the sheet pallet of this embodiment is used, in which a large number of items 5 are stacked on a floor 4 or the like with sheet pallets 1 interposed therebetween. If you want to stack the sheets on top of that, hold the gripping part 3 of the sheet pallet 1 and hold the sheet pallet 1.
Place the platen 7 of the forklift 6 at the bottom of the
, and pull out platen 7. The sheet pallet of the above-described example with dimensions of X = 1100 mm, Y = 1100 mm, and Z = 100 mm in Fig. 4 was actually tested using an auto palletizer, and the load was tested while being moved by a forklift using a forklift. The results of the collapse test etc. are shown in Table 1 below. Comparative examples are also shown in the same table for comparison.

【table】
I can't go


Ivy (×)

EVA(VA%7%) EVA0.2〓(product EVA side
EVA side Fertilizer bag Bag and sheet are adhesive ○
○ × −
surface) 0.64(−)
− Pull out the sheet


I can't go


Ivy (×)


Cardboard Cardboard and sheet ○
○ × −

The adhesive sheet


can be pulled out


Kinakatsuta(×)

[Results of the idea]

The sheet pallet of this invention has good pullability, prevents adhesion to loads such as paper bags, and does not cause pinholes or breakage in paper bags, making it suitable for use in polyethylene fertilizer bags. This reduces the possibility of peeling off the front printing, prevents the cargo from collapsing while being moved by a forklift, and prevents the cargo from collapsing even when loaded sheet pallets are stacked in two or three tiers. It can also be used in palletizer machines for sheet pallets.

[Brief explanation of drawings]

Figure 1 is a diagram showing the cross-sectional shape of the sheet pallet of the present invention, Figures 2 and 3 are perspective views of the embodiment of the invention, Figure 4 is a plan view of the embodiment of the invention, and Figure 5 is a diagram showing the cross-sectional shape of the sheet pallet of the present invention.
Fig. 6 is a diagram showing the configuration of the sheet forming apparatus for sheet pallets of the present invention, Fig. 7 is a developed view of the cross-sectional shape of the grain roll for the non-loading surface used in the above-mentioned apparatus, and Fig. 8 is a diagram showing the structure of the sheet forming apparatus for the sheet pallet of the present invention. FIG. 9 is a developed view of the cross-sectional shape of the grained roll for the cargo loading surface to be used, and is a diagram showing an example of the mode of use of the embodiment of the present invention. 1... Sheet pallet, 2... Placement section, 3...
Gripping part.

Claims (1)

[Scope of utility model registration request] In a sheet pallet made of thermoplastic resin, unevenness with a 10-point average roughness of 20μ or more and less than 80μ is formed on the cargo loading surface and non-loading surface of the sheet pallet, and the unevenness is formed so that the cargo loading surface and the non-loading surface do not interlock with each other. A sheet pallet characterized by having different shapes and sizes.