JPH0250810A - Manufacture of pallet - Google Patents

Abstract

PURPOSE:To produce the pallet having high bending strength and capable of fixing a non-skid member effectively by a method in which while a pallet body is molded by covering a core material with glass fiber reinforced thermoplastic resin, platelike elastomer is welded under heating to the pallet body. CONSTITUTION:The lower half of elastomer is received in the recessed part F of a bottom force, and a plurality of resin sheets 36 are placed on a projected part 34A. This resin sheet 36 is the sheet made of polypropylene wherein long glass fiber is buried, whereby after molding, its strength is heightened remarkably by the glass fiber. Core material 18 having the area a little smaller than that of the resin sheet 36 is placed on this resin sheet 36, and further the thin resin sheet 38 containing the same material as that of the resin sheet 36 is placed on this core material 18. In this state, when a top force 32 is engaged with the bottom force 34 and they are pressurized and heated, the resin sheets 36 and 38 are melted and are closely stuck mutually, and then covers surely the surrounding of the core material 18, thereby making the synthetic resin 16 in which the core material 18 is buried, and simultaneously the part of the resin enters in each deep groove and becomes leg part 14.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing pallets used in cargo handling operations.

[Background technology]

A pallet for loading heavy objects and transporting them by a forklift or the like is constructed by assembling wooden boards into a frame shape. This wooden pallet has an uneven surface and has problems with nails etc. protruding, so synthetic resin pallets are being used instead. These synthetic resin pallets are impact resistant, lightweight, and have a long lifespan, but due to the nature of the synthetic resin, their bending strength is lower than that of wooden pallets, and their smooth surfaces make them easy to slip when loaded onto a forklift. . In order to fix the anti-slip member to such a pallet, it is necessary to heat-fuse the two without heating them.
(Refer to No. 26894) It is a relatively long work.

In consideration of the above facts, the present invention aims to provide a method for manufacturing a pallet that is made of synthetic resin, has high bending strength, and can efficiently fix anti-slip members.

[Summary and operation of the invention]

The present invention forms a pallet body in which the core material is embedded in the resin by applying pressure in a mold with the core material sandwiched between thermoplastic resin molded sheets that have been heated and melted in advance and reinforced with glass fibers. The special feature is that one side of the plate-like elastomer is thermally welded to the molded sheet within the mold during this pressurization.

In this way, in the present invention, by melting the glass fiber reinforced thermoplastic resin molded sheet in the mold and embedding the core material,
The strength of the pallet body is improved.

Wood is suitable as this core material. Moreover, since one side of the elastomer inserted into the mold is heat-welded to the resin constituting the outer periphery of the pallet body before molding, the other side of the elastomer is exposed from the pallet. Therefore, the elastomer that is the anti-slip member can be molded simultaneously with the molding of the pallet, and the pallet can be manufactured efficiently.

As this elastomer, an olefin elastomer based on polypropylene, polyethylene, etc. is suitable.

[Embodiments of the invention]

FIG. 1.2 shows a pallet 10 according to this embodiment. This pallet 10 has a main body 12 having a rectangular planar shape.
Three leg portions 14 (14A, 14B, 14C) integrally protrude from the top.

The main body 12 has a core material 18 embedded inside a synthetic resin 16. For this reason, the core material 18 is covered with a synthetic resin 16, and a portion of this synthetic resin 16 is integrally connected and extended to the leg portions 14.

The synthetic resin 16 is a thermoplastic synthetic resin reinforced by glass fiber filling. Core material 18 is plywood, MDF
(medium density fiberboard) etc. can be applied.

As shown in FIG. 2, three leg parts 14A to 14C are formed on the back surface of the main body 12 in parallel with each other and at equal intervals, and have a hollow shape with a deep groove 22 formed from the tip. This deep groove 22 is divided into a plurality of parts by ribs 24.

An elastomer plate 26 is fixed by heat welding to the surface of the main body 12O from which the leg portions 14 protrude, that is, to the back surface opposite to the loading surface. This elastomer plate 26 has a flat plate shape, one side of which is embedded in the synthetic resin 16, and the other side protrudes from the synthetic resin 16.

Therefore, when the fork of the forklift is inserted between the legs 14 and the pallet NO is lifted, the fork and the pallet 10 do not slip against each other.

FIG. 3 shows a stopper die 32 and a lower die 34 for manufacturing this pallet 10. The upper mold 32 has a lower mold 34
When the main body 1 is in close contact with the protrusion 34A of the lower mold,
A recessed portion 32A for forming a portion 2 is provided. In addition, when the lower mold 34 is in close contact with the upper mold 32, the leg I4
A plurality of deep grooves for forming the projection 34A are provided in the protrusion 34A.

These deep grooves are deep grooves 34B and 34C for forming the legs 14A and 14G, and deep grooves 34D and 34E for forming the leg 14B. The sides are closed by the upper mold 32 when the upper mold 32 and the lower mold 34 are fitted together. deep groove 3
The deep grooves 4B and 34C and the deep grooves 34D and 34E communicate with each other on the front and back sides of the paper in FIG. 3, and form a cylindrical leg portion as shown in FIG. 2.

Furthermore, a recess 34F for accommodating the lower side of the elastomer plate 26 is formed in the lower mold protrusion 34A.

Next, a procedure for manufacturing the pallet 10 according to this embodiment will be explained.

As shown in Figure 3, the elastane 7 is placed in the lower mold recess 34F
26, and a plurality of resin sheets 36 (for example, three sheets) are placed on the protrusion 34Δ.

The elastomer 26 is an olefin elastomer based on polypropylene or the like. Also, the resin sheet 36
may cover the entire surface of the lower mold protrusion 34A, but may be concentrated near the deep grooves 34B, C and 34D, E so that they can easily enter these grooves. As this resin sheet 36, a long glass fiber reinforced thermoplastic resin sheet can be used, for example, X sheet (trade name, manufactured by Idemitsu Petrochemical Co., Ltd.) can be used. This resin sheet 36 is a polypropylene sheet in which long glass fibers are embedded, and after molding, the strength is greatly improved by the glass fibers.

A core material 18 having a slightly smaller area than the resin sheet 36 is placed on the resin notebook 36, and a thin resin sheet 38 made of the same material as the resin sheet 36 is further placed on top of the core material 18.

In this state, the stopper die 32 and the lower die 34 are aligned, and a pressure of about 100 kg/ant is applied between them. In this case, it is preferable that the resin sheet 36, 38 is maintained at around 200°C, and the upper mold 32 and lower mold 34 are maintained at a temperature of 60 to 80°C.
It is preferable to maintain the temperature around ℃. As a result, the resin sheets 36 and 38 melt and adhere to each other, securely covering the periphery of the core material 18, embedding the core material 18, and forming the synthetic resin 16 shown in FIG. It goes in and becomes the leg part 14.

Further, the elast 726 is pressurized so that half of it enters into the resin sheet 36 and is thermally welded.

When plywood is used as the core material 18, the wall thickness before molding becomes thinner due to pressure after molding, and the wall thickness of the core material 18 becomes 15.
The total thickness of the main body 12 is approximately n+m and the total thickness of the main body 12 is approximately 20 mm, which is a value that can reliably maintain the predetermined strength specified in JIS ZO602. That is, the bending strength of this pallet 10 is improved by about 1.3 to 1.5 times with the same wall thickness compared to a case where the entire pallet is made of MDF alone.

Further, since the surface of this pallet 10 is covered with synthetic resin 16, the surface is smoother than that of a wooden pallet, and even when printing papers and the like are stacked in multiple layers, they will not be damaged. Additionally, they are lighter in weight than wooden pallets, making them easier to handle.

In the above embodiment, in order to fix the elastomer plate 26 to the upper surface of the pallet body 12, another elastomer plate may be placed in the recess 32A.

In the above embodiment, a part of the resin sheet 36 is flowed into the deep grooves 34B to 34E during molding to form the legs 14, but the legs 14 may be separately manufactured in advance and fixed to the main body 12 within the mold. .

The pallet body is formed by covering the pallet with glass fiber reinforced thermoplastic resin, and the plate-shaped elastomer is thermally welded to the pallet body, which has an excellent effect of efficiently producing a small pallet with high bending strength.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing a pallet to which the present invention is applied, FIG. 2 is a rear perspective view of this pallet, and FIG. 3 is a longitudinal cross-sectional view showing the relationship with a mold during manufacturing. 10...Pallet, 12...Main body, 14.14A, 14B, 14C...Legs, 16...
Synthetic resin, 18... Core material, 26... Elastomer plate, 32... Upper mold, 34... Lower mold, 34F... Recessed portion.

Claims (1)

[Claims] (1) Forming a pallet body in which the core material is embedded in the resin by applying pressure in a mold with the core material sandwiched between thermoplastic resin molded sheets that have been heated and melted in advance and reinforced with glass fiber; A method for manufacturing a pallet, characterized in that one side of the plate-shaped elastomer is thermally welded to the molded sheet within a mold during this pressurization.