Spacer core for culturing oysters

Abstract

To provide a spacer core for culturing oysters which can maintain required intensity as a spacer core for culturing oysters even being immersed in the sea for a long period, and in which a paper tube part is quickly decomposed relative to plastic, even if the spacer core is flowed to the sea, thereby reducing environmental loads.SOLUTION: There is provided a spacer core for culturing oysters which is used by being arranged between shells. The spacer core for culturing oysters is made of a paper tube in which an epoxy resin solution is impregnated.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a spacer core for oyster cultivation. More specifically, the spacer core for oyster cultivation is made of a paper tube impregnated with an epoxy resin, and can maintain the strength required for a spacer core for a long period in seawater. Moreover, even if it is washed into the sea, the paper tube portion quickly decomposes, so that the spacer core for oyster cultivation has a low environmental impact.

[0002] Generally, oysters are cultivated through the processes of seedling collection, restraint, main hanging, and growth, followed by harvesting.

[0003] Specifically, several scallop shells (2) connected together with spacer cores in between (seedling strings 10) are placed in the sea, and oyster larvae are attached to the scallop shells (seedlings). The seedling strings with the oyster larvae attached are then moved to a restraining shelf on a coastal tidal flat and hung there for about a year (restoration). After that, new hanging strings are made from the shells with the larvae attached, and the hanging strings are submerged in the sea and left to hang down, grow, and be harvested.

[0004] The spacer core (1) sandwiched between the scallop shells (2) used in seedling collection lines and hanging lines (hereinafter referred to as "seedling collection lines, etc.") is usually made of plastic.

[0005] If the spacer cores are made of plastic, their strength will not decrease even if they are submerged in the sea for a long period of time, and they can be reused after harvesting. However, if the spacer cores are submerged in the sea for a long period of time, the ropes of the seedling collection lines may break. If the ropes (3) break, the plastic spacer cores will be released into the sea, and the plastic released into the sea will not decompose and will remain as marine debris. This is a problem.

[0006] Spacer cores made of wood or bamboo have been proposed as spacer cores that will decompose quickly even if released into the ocean, but there is a risk that they will rot if submerged in the ocean for a long period of time, and will no longer be able to maintain their strength, and will no longer function as spacer cores.

[0007] Therefore, there is a need to develop a spacer core for oyster farming that can maintain its strength even when submerged in the sea for long periods of time, and whose paper tube portion decomposes quickly when released into the sea, thereby posing a low burden on the environment. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent Publication No. 2022-135739 Summary of the Invention [Problem to be solved by the invention]

[0009] Patent Document 1 describes a ceramic spacer for cultivated oysters, which is made by baking a mixture of china clay and crushed recycled materials such as roof tiles, bricks, and glass as the main raw material.

[0010] However, since the ceramic spacer described in Patent Document 1 is made of ceramic, there is a risk that the rows of seedlings may collide with each other and chip if they are submerged in the sea for a long period of time, and the strength of the spacer may not be maintained.

[0011] The inventors made it their technical task to solve the above-mentioned problems, and as a result of numerous prototypes and experiments through trial and error, they made the remarkable discovery that a paper tube impregnated with an epoxy resin solution can maintain its strength as a spacer core even when left in the sea for a long period of time, and even if released into the sea, the paper tube portion quickly decomposes, making it an environmentally friendly spacer core for oyster farming, and thus achieved the above-mentioned technical task. [Means for solving the problem]

[0012] The above technical problems can be solved by the present invention as follows.

[0013] The present invention relates to a spacer core for oyster farming which is placed between shells, the spacer core being a paper tube impregnated with an epoxy resin solution.

[0014] The present invention also relates to the spacer core for oyster farming, wherein the epoxy resin concentration of the epoxy resin solution is 30% by weight or more and 55% by weight or less.

[0015] The present invention also relates to the spacer core for oyster farming, wherein the cardboard tube has an outer diameter of 18±0.5 mm, an inner diameter of 12±0.3 mm, and a height of 15±0.5 mm. Effect of the Invention

[0016] Since the spacer core for oyster farming in the present invention is a paper tube impregnated with an epoxy resin solution, it can maintain the strength required to function as a spacer core even when used for seedling collection or the like and immersed in the sea for a long period of time.

[0017] Furthermore, even if they are released into the ocean, the paper tube portion will quickly decompose, making them a spacer core with little environmental impact.

[0018] Furthermore, if the concentration of the epoxy resin in the epoxy resin solution to be impregnated is 30% by weight to 55% by weight, the epoxy resin will easily impregnate the paper tube, resulting in a spacer core with even greater strength.

[0019] Furthermore, if the outer diameter of the paper tube is 18±0.5 mm, the inner diameter is 12±0.3 mm, and the height is 15±0.5 mm, it becomes a spacer core that can be suitably used for seedling collection. [Brief description of the drawings]

[0020] [Figure 1] This is an example of a seedling collection group. [Diagram 2] 1 shows a spacer core according to the present invention before being immersed in the sea. [Diagram 3]This is a spacer core of the present invention that was immersed in the sea for about 9 months. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The spacer core for oyster farming in the present invention is a paper tube impregnated with an epoxy resin solution.

[0022] The cardboard tube is not particularly limited, but an example is a cardboard tube that is composed of one sheet of liner paper, four sheets of cardboard tube base paper, one sheet of liner paper, and one sheet of kraft paper, in that order from the inside of the cardboard tube.

[0023] The size of the cardboard tube is not particularly limited, but examples include cardboard tubes with a diameter of 5 mm to 51 mm, a thickness of 1 mm to 10 mm, and a height of 10 mm to 300 mm.

[0024] In particular, if the outer diameter of the cardboard tube is 18±0.5 mm, the inner diameter is 12±0.3 mm, and the height is 15±0.5 mm, it can be suitably used for seedling collection.

[0025] For use in seedling collection, it is preferable that the average weight of one paper tube is about 1.7g.

[0026] The epoxy resin solution to be impregnated into the paper tube is not particularly limited, but an example is Bond E-Set (containing about 55% by weight of epoxy resin / manufactured by Konishi Co., Ltd.).

[0027] The epoxy resin content in the epoxy resin solution is preferably 30% by weight to 55% by weight, and more preferably 35% by weight to 40% by weight.

[0028] If it is less than 30% by weight, the strength cannot be maintained, whereas if it exceeds 55% by weight, the epoxy resin becomes too thick and does not penetrate into the paper tube, which may result in a decrease in strength. EXAMPLES

[0029] The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited thereto.

[0030] (Resin Selection) A paper tube (outer diameter 18 mm, inner diameter 12 mm, height 15 mm / manufactured by Kyoei Paper Tube Co., Ltd.) was immersed in each of the following resins for 1 minute to impregnate the paper tube with each resin: epoxy resin (Bond E Set / resin concentration approximately 55% by weight / manufactured by Konishi Co., Ltd.), acrylic resin solution (SEK-301 / resin concentration 36.0% by weight to 40.0% by weight / manufactured by Toagosei Co., Ltd.), urethane resin (Hydran HW-350 / resin concentration 29% by weight to 31% by weight / manufactured by DIC Corporation), and varnish resin (water-based varnish transparent clear / resin concentration 30% by weight to 40% by weight / manufactured by Washin Paint Co., Ltd.), and then dried at 160°C for 1 hour.

[0031] The paper tubes impregnated with each resin were immersed in water for one week, then naturally dried indoors for one week. The maximum load (N) until the paper tubes were crushed was measured using a universal material testing machine.

[0032] The number of samples measured was n=7, and the maximum and minimum values ​​were cut off to obtain the average value of n=5.

[0033] The results are shown in Table 1. Note that Comparative Example 1 is the maximum load of the cardboard tube itself.

[0034] [Table 1]

[0035] (Maintaining strength) The same oyster farming spacer core as in Example 1 was used for the test seedling collection (Figure 1), and the seedling collection and inhibition processes were carried out by immersing it in seawater in the test area for approximately one year from July 25, 2022 to July 5, 2023.

[0036] After the suppression process, the spacer core was recovered from the sea and dried. The maximum load was measured in the same manner as in Example 1 and was found to be 62.344 (N), indicating that the strength required for the spacer core was maintained.

[0037] (Resin concentration) An epoxy resin solution (Bond E-set / resin concentration approximately 55% by weight / manufactured by Konishi Co., Ltd.) was diluted with thinner to prepare epoxy resin solutions with concentrations No. 1 to 8 in Table 2, which were then impregnated and dried in the same manner as in Example 1.

[0038] The paper tubes impregnated with epoxy resin solutions of various concentrations and dried were immersed in water and dried in the same manner as in Example 1, and the maximum load (N) was then measured.

[0039] The results are shown in Table 2.

[0040] [Table 2]

[0041] As shown in Tables 1 and 2 and in the tests for use in oyster farming, it was proven that the spacer core of the present invention has a high maximum load of 230 N or more even after being immersed in water for one week, and that it can maintain its strength for a long period of time, approximately one year, even when actually immersed in seawater. [Industrial Applicability]

[0042] The spacer core for oyster farming in the present invention is made of a paper tube impregnated with epoxy resin, and can maintain the strength required for a spacer core for oyster farming over a long period of time. Moreover, even if it is washed into the sea, the paper tube portion decomposes more quickly than plastic, making it an oyster farming spacer core that places less strain on the environment. Therefore, the present invention has high industrial applicability. [Explanation of symbols]

[0043] 1 Spacer core 2. Shells 3. Rope 10 Seedling collection

Claims

1. A spacer core for oyster cultivation is disposed between shells and used, the spacer core being a paper tube impregnated with an epoxy resin solution.

2. 2. The spacer core for oyster farming according to claim 1, wherein the epoxy resin concentration of the epoxy resin solution is 30% by weight or more and 55% by weight or less.

3. 3. The spacer core for oyster farming according to claim 1 or 2, wherein the cardboard tube has an outer diameter of 18±0.5 mm, an inner diameter of 12±0.3 mm, and a height of 15±0.5 mm.

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