JPH0316900B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for manufacturing an aquaculture float,
The present invention aims to provide a method in which the hollow molded body serving as the outer shell and the foamed body inside have good integrity and can be manufactured efficiently.

Traditionally, floats used for cultivating marine products such as oysters and kelp have been made by filling a thermoplastic resin foam inside a synthetic resin hollow molded body, which is considered to be suitable for its excellent strength and light weight. .

The above float is manufactured by filling a hollow molded body with expandable thermoplastic resin particles using air, and then introducing steam to heat and fuse the resin particles to each other and the hollow molded body. . However, when air is filled with resin particles into a sealed hollow molded body, the air cannot be discharged smoothly, resulting in problems such as time-consuming filling and insufficient filling of resin particles.

Also, during steam heating, if the steam is not properly discharged, the steam cannot be supplied to the entire hollow molded body, resulting in problems such as poor fusion of resin particles and insufficient strength.

Therefore, in the present invention, we have developed a method that solves the problems of the conventional method and allows the air and steam used for filling the resin particles to be efficiently discharged. A hollow molded body having an opening is formed, a net-like body having a filling pipe insertion port is temporarily attached to cover the opening of the hollow molded body, and a filling pipe of expandable thermoplastic resin particles is inserted into the insertion opening. The above particles are filled into the hollow molded body together with air, and then a steam pipe is inserted into the insertion port, and the expandable thermoplastic resin particles are integrated by foam fusion in the hollow molded body by steam heating, and then a network-like shape is formed. After the body is removed, the opening of the hollow molded body is closed and sealed with the non-foamed synthetic resin.

Next, embodiments of the present invention will be illustrated below with reference to the drawings.

First, in FIG. 1, 1 is made of hard synthetic resin such as glass fiber reinforced synthetic resin (FRP),
It is a hollow molded body that constitutes the outer shell of the aquaculture float, and although it has an elongated bale shape in the figure, it can be freely changed depending on the shape of the aquaculture float.

Reference numeral 10 denotes an opening, which is formed at one end of the hollow molded body 1. The size of the opening 10 is formed to be slightly larger than the diameters of a filling pipe and a steam pipe, which will be described later.

As the non-foamed synthetic resin for forming the hollow molded body 1, glass fiber reinforced resin made of unsaturated polyester resin is suitable due to its excellent strength and durability, but vinyl chloride, ABS, polycarbonate, and other relatively hard materials may also be used. Synthetic resins can also be used.

Then, the hollow molded body 1 is formed from the synthetic resin using a hollow molding method such as blow molding or rotational molding, or various molding methods for glass fiber reinforced resin.

Next, the hollow molded body 1 manufactured as described above
A net-like body 2 such as a wire mesh is temporarily attached to the opening 10 of.

The mesh body 2 may be made of a material that has heat resistance and strength that can withstand steam heating and foaming pressure, which will be described later.
In addition to metal nets, synthetic resin nets can also be used. Furthermore, the mesh spacing of the net-like body 2 is set to such an extent that the expandable thermoplastic resin particles filled in the hollow molded body 1 do not fall off.

Then, tape the outer periphery of the mesh body 2 with craft tape 2.
It is pasted around the opening 10 of the hollow molded body 1,
A filling pipe insertion opening 21 is formed in the center of the net-like body 2 (see FIG. 2). In addition, to temporarily attach the net-like body 2 to the hollow molded body 1, use craft tape 20.
In addition, various adhesive tapes, adhesives, etc. can be used, but it is preferable to use one that is easy to apply, that allows the net-like body 2 to be easily removed after a predetermined process is completed, and that leaves no residue. Alternatively, the mesh body 2 may be fitted and attached to the opening 10.

Next, a pipe 30 filled with expandable thermoplastic resin particles is inserted into the insertion hole 21 of the net-like body 2, and the resin particles P are fed into the hollow molded body 1 together with air (see FIG. 3).

The above-mentioned expandable thermoplastic resin particles P are polystyrene, polyethylene, polypropylene, and other various thermoplastic resins with a foaming agent added and molded into pellets or granules, which are pre-foamed by heating in advance. is sometimes used. Among the raw resins, particularly preferred are foamed particles in which at least a portion of a polyolefin resin and a polystyrene resin are graft-bonded, such as polyethylene particles, which are made into cores, and styrene monomer is absorbed into the cores, and styrene monomer is absorbed into the cores. Particles graft-bonded to polyethylene are obtained by polymerizing a monomer, and foamed particles (trade name: PIOCELAN, manufactured by Sekisui Plastics Co., Ltd.) are obtained by adding a blowing agent to these particles, and the above-mentioned foamed particles The foam formed from this material is flexible and has good cushioning properties, making it suitable for use.

The filling pipe 30 for the resin particles P is connected to a storage tank 32 for the resin particles P via a particle feeding hose 31, and a pressurized air introduction part 33 is provided in the middle of the particle feeding hose 31. Reference numeral 40 denotes a support base, which allows the hollow molded body 1 to be held obliquely so that the opening 10 side is higher, making it easier to perform the filling operation.

Then, the resin particles P together with the pressurized air from the introduction part 33 are introduced into the filling pipe insertion port 21 of the net-like body 2.
After that, it is sent into the hollow molded body 1 and filled. At this time, the pressurized air sent together with the resin particles P passes through the mesh of the net-like body 2 and is discharged to the outside.

When the resin particles P are completely filled into the hollow molded body 1, the filling pipe 30 is pulled out from the insertion opening 21 of the net-like body 2, and the insertion opening 21 is inserted into the craft tape 2.
Temporarily occlude with 2nd grade (see Figure 4). Note that the craft tape 22 can be used as a temporary closing means for the insertion port 21.
In addition to pasting a cover material, it is also possible to fit a cover material into the insertion opening 21 as appropriate.

Next, the steam pipe 5 is inserted into the hollow molded body 1 through the insertion port 21, and steam is ejected to heat and expand the resin particles P inside, thereby melting the resin particles P and the hollow molded body 1. Unify the clothing (No. 5)
(see figure).

As the steam pipe 5, a steam outlet 50 is formed at the tip of a SUS pipe or the like, 51 is a valve, and the steam pipe 5 is connected to an appropriate steam supply source via a rubber hose 52 or the like.

Then, the steam pipe 5 pierces through the craft tape 22 that temporarily closed the insertion port 21 and passes through the hollow molded body 1.
After inserting it to the innermost part and blowing out steam to heat and foam the resin particles P at that location and fuse them,
While gradually pulling out the steam pipe 5, the surrounding resin particles P are heated and foamed to fuse and integrate, and the steam outlet 50 of the steam pipe 5 is successively pulled out until the steam pipe 5 approaches the insertion port 21.
is moved to fuse and integrate the resin particles P throughout the interior of the hollow molded body 1. At this time, the steam ejected into the hollow molded body 1 passes through the mesh of the net-like body 2 and is discharged to the outside.

In addition, the drawing speed of the steam pipe 5 is determined as follows: As the resistance increases when surrounding resin particles P fuse together,
Pull out while adjusting the increase in the above resistance force as a guide. In addition, resin particles P near the insertion port 21
are heated and fused by the steam pressure of the steam discharged from the inside, so when the steam jet port 50 moves close to the insertion port 21, the jet of steam may be stopped and the steam pipe 5 may be pulled out.

As described above, the resin particles P in the hollow molded body 1
After heating and foaming to fuse and integrate, the whole is cooled. As for the cooling time, it is practically sufficient to carry out the cooling for about 12 hours, and to cool it to the extent that the next step can be carried out.

Next, after removing the net-like body 2, the craft tape 20, etc. from the cooled hollow molded body 1, the opening 1
0 is closed and sealed with the same resin as the hollow molded body 1 (see FIG. 6).

Therefore, the manufactured float is covered with the hollow molded body 1 on the entire outer surface, and is made of a foam body that is fused and integrated inside.
P′ is not exposed to the outside.

Among the above manufacturing methods, the craft tape 22 is pasted on the mesh body 2, and the insertion opening 21 for the filling pipe 3 is
The reason why the steam pipe 5 is inserted by breaking through the craft tape 22 after temporarily closing the is because the diameter of the steam pipe 5 is smaller than the diameter of the filling pipe 3, so there is a gap between the steam pipe 5 and the insertion port 21. This is to prevent resin particles from falling off. Therefore, if the diameters of the filling pipe 3 and the steam pipe 5 are the same, or if the resin particles can be prevented from falling off by appropriate means, the craft tape 22 is not necessary.

Furthermore, during steam heating, the steam pressure inside the hollow molded body 1 increases, and a pressure of about 0.4 to 0.8 Kg/cm ² is applied, and the temperature becomes high. When the molded body 1 is made of glass fiber reinforced resin, the pressure resistance is high, so the above-mentioned cooling is not necessary.

Floats manufactured using the manufacturing method described above are used by connecting them with ropes or chains, or floating them in the sea by hanging aquaculture cages for oysters, etc. However, accessories such as connecting members are conventionally used. Since the same one is used, detailed explanation will be omitted.

The specific structure of the float is as follows:
The hollow molded body 1 is made of glass fiber reinforced resin made of polyester resin, and is shaped like an elongated bag with a diameter of 300 mm and a length of 3000 mm, and has a wall thickness of 5 ply, that is, approximately 5 mm, and has the polyolefin resin and polystyrene resin inside. A foam made of a resin that is at least partially grafted with a resin and has an expansion ratio of 30 times.
A float filled with 10 kg was manufactured and was successfully used.

According to the method of the present invention configured as described above, by temporarily attaching the net-like body 2 to the opening 10 of the hollow molded body 1, when filling the resin particles P with air, air is released from inside the hollow molded body 1. It passes through the net-like body 2 and is smoothly discharged, which eliminates the conventional drawback of air accumulating in the hollow molded body 1 and inhibiting the filling of resin particles P, which has a great effect on speeding up and increasing the efficiency of the filling operation. There is. Further, since insufficient filling of the resin particles P and uneven packing density in the hollow molded body 1 do not occur, it is effective for stabilizing the strength and quality of the manufactured float.

Furthermore, even during steam heating, the steam can be well discharged through the mesh body 2, so the heating efficiency is also good, and the resin particles P in the entire hollow molded body 1 can be uniformly foamed and fused. Solve the problem of poor fusion. Further, since moisture generated from heated steam is less likely to accumulate inside the hollow molded body 1 or inside the foam, problems such as deterioration of the quality of the foam and increase in float weight due to the moisture can be solved.

Therefore, it has a great effect on increasing the efficiency of steam heating work and improving the quality of floats.

Moreover, since the net-like body 2 is only temporarily attached to the opening 10 of the hollow molded body 1 and can be easily removed after the steam heating is completed, it will not get in the way of the subsequent work to close the opening 10, and it will not be unnecessary to the float. It exhibits many excellent features, such as leaving no residual components and having no effect on the performance of the float, as well as being inexpensive to manufacture.

[Brief explanation of the drawing]

The figures illustrate embodiments of the present invention; FIG. 1 is a cross-sectional view of a hollow molded body before filling with resin particles, FIG. 2 is an enlarged front view of the vicinity of the opening, and FIG. A schematic sectional view showing the process, Figure 4 is an enlarged front view of the vicinity of the opening where the insertion port is temporarily closed, and Figure 5 is a schematic sectional view showing the process.
The figure is a cross-sectional view of the steam heating process, and FIG. 6 is a cross-sectional view of the manufactured float. DESCRIPTION OF SYMBOLS 1... Hollow molded body, 10... Opening, 2... Reticular body, 21... Insertion port, 30... Filling pipe, 5...
...steam pipe, P...resin particles.

Claims (1)

[Claims] 1. A hollow molded body made of non-foamed synthetic resin and having a filling opening is formed, and a net-like body having a filling pipe insertion opening is temporarily attached to cover the opening of the hollow molded body,
A pipe filled with expandable thermoplastic resin particles is inserted into the insertion port, and the particles are filled with air into the hollow molded body. Next, a steam pipe is inserted into the insertion port, and the foamable thermoplastic resin is heated by steam heating. A method for manufacturing an aquaculture float, which comprises integrating particles in a hollow molded body by foam fusion, and further, after removing the net-like body, the opening of the hollow molded body is closed and sealed with the non-foamed synthetic resin. 2. The method for producing an aquaculture float according to claim 1, wherein a glass fiber-reinforced unsaturated polyester resin is used as the non-foamed synthetic resin.