JPH0216623Y2 - - Google Patents

Description

[Detailed explanation of the idea]

This invention relates to fence nets for fixed nets, and in more detail, it relates to fixed nets for salmon, fixed nets for firefly squid, etc. whose fishing season is 2
Fixed nets with a relatively short fishing season, such as ones that last for about 3 months, or general fixed nets with a fishing season of about 5 to 6 months, such as spring nets or summer nets, maintain sufficient safety in use during the fishing period. death,
This relates to fence nets that can be disposed of into the sea at the end of the fishing season, allowing them to disappear naturally in a short period of time. Fixed nets consist of fence nets, corral nets, ascending nets, box nets, etc., and are permanently placed in a predetermined location in the sea. At the same time, they are guided into a pen net, and then the guided fish are further guided up into the box net using a net to catch fish. Because the sea areas and water depths in which fish migrate naturally differ depending on their migratory form and each species of fish, migratory fish routes are extremely wide, and it is possible to use these wide migratory fish routes. In order to block threats as much as possible, the length of fence nets laid will inevitably become long, and even small fixed nets can be over several hundred meters in length, and large fixed nets can be several thousand meters long. Since it is essential that the net be spread continuously from the water surface to the seabed to prevent schools of threatened fish from escaping, the net area of the fence net is extremely large.
Since schools of migratory fish migrate by tidal currents, the fence nets are laid and stretched in a direction approximately perpendicular to the tidal currents, and as a result, a large amount of tidal current resistance is added to the nets. A large number of fixed anchors such as dohyō (dohyō) or gold anchors are used in order to provide sufficient countermeasures. Furthermore, in order to prevent the netting from being blown away due to resistance to the current, a number of measures have been taken to prevent the netting from being blown away due to resistance to the tidal currents, such as interweaving high-density netting, interposing sinking wire, or installing hem netting. be. By the way, most of the current fence nets are made of relatively expensive and durable net fabric knitted from synthetic fibers, so even during the fishing season, which lasts only 2-3 to 6 months, It takes a lot of effort, expense, and time to lay and erect the fence, and then it must be removed and dismantled at the end of the fishing season, and removal requires a lot of work, such as drying the fence nets and removing silica shellfish. Furthermore, the management and maintenance costs of transporting huge volumes of fence netting and preparing warehouses to store it are enormous, as well as the increasing working age and labor shortages in recent years. The current situation is that there is a strong desire to reduce these incidental operations and save labor. On the other hand, in response to this situation, attempts have been made to make fence nets from plant fibers such as straw rope and manila hemp, and to dump them into the sea at the end of the fishing season, thereby greatly reducing incidental work, costs, and labor. With fiber fences, the decomposition and deterioration that progresses as they are used underwater varies significantly depending on water temperature, tidal current speed, water quality, etc.
Until now, no adequate solution has been found because the risk of net breakage or net washing being washed away midway through the fishing season is extremely high. The present invention provides a fencing net that solves this problem, and the embodiments of the present invention will be described below in detail based on the drawings. Fig. 1 is an explanatory cross-sectional view of the strands, and Fig. 2 is a knotless netting. FIG. 3 is a cross-sectional view of the strand after heat treatment, FIG. 4 is a cross-sectional view of the net fabric, and FIG. 5 is an explanatory view of the knotted net fabric. The oil and fat agent 1 is selected from oils and fats that are in a solidified state at room temperature and whose melting point is higher than room temperature, such as grease and lard. It is impregnated with oil-impregnated yarn 2 of an appropriate thickness. In this case, the method of impregnating the oil and fat agent 1 is to forcibly impregnate the oil and fat agent 1 while running it through the coagulated oil and fat agent 1, and to run it in a liquid in which the oil and fat agent 1 is melted. There is a method in which the material is impregnated by passing it through and then cooled and solidified, but there are no particular restrictions on either method. The oil-impregnated yarn 2 is used in order to retain the oil and fat agent 1 so that it does not scatter during the production of strands, net ropes, or knitting the net and impede the workability, and to sufficiently impregnate the oil and fat agent 1. A twist structure as loose as possible is desired, and single-twist, double-twist or triple-twist ropes twisted at a twist pitch of about 5 to 20 twists per m are suitable. Any number of oil-impregnated yarns 2 impregnated with the oil agent 1 and linen, cotton, hemp, palm,
Alternatively, the strands 4 are formed by mixing and twisting unimpregnated yarns 3 made of straw or the like in an appropriate ratio. A knotless net fabric 4A is formed by twisting and knitting two to three of these strands 4, and two to four strands of the strands 4 are further twisted to form a net rope 4'. The knotted net fabric 4B is formed by knitting the net fabric rope 4'. By heat-treating the thus formed knotless net fabric 4A or knotted net fabric 4B at a temperature higher than the melting point of the oil/fat agent 1, the oil/fat agent 1 impregnated into the oil/fat impregnated yarn 2 is removed. The melted and low-viscosity oil/fat agent 1 is diffused and permeated throughout the unimpregnated yarn 3 which is melted and mixed and twisted, and is generally carried out at the same time as the heat setting of the fabric. The present invention has the above-mentioned configuration, in which the strands 4 or the net rope 4' forming the net fabric are entirely composed of the non-impregnated yarn 3 and the oil-impregnated yarn 2 made of vegetable fiber material. In addition, since the oil and fat agent 1, which is solidified at room temperature, is melted and diffused throughout the non-impregnated yarn 3, the oil and fat agent 1 is impregnated in a solidified state again when used underwater. Because of this, it is difficult to wash away even when subjected to the washing action of tides and waves, and as a result, the rotting and deterioration of the non-impregnated yarn 3 or the oil-impregnated yarn 2 is significantly suppressed, and the fishing season lasts at least 5 to 6 months. The interior can be used safely. According to the present invention, a strand 4 is obtained by mixing and twisting the oil-impregnated yarn 2 impregnated with the oil-fat agent 1 which exhibits a solidified state at room temperature and the non-impregnated yarn 3 in an appropriate ratio, or the strand 4 is further combined and twisted. The mesh rope 4' is knitted to form a knotless mesh fabric 4A or a knotted mesh fabric 4B, and the oil and fat agent 1 is solidified even when forming the strands 4 and the mesh rope 4' or knitting the mesh. Since processing is carried out while it is impregnated inside the strand 4 or net rope 4', there is no slipping or oil leakage, resulting in extremely good workability and handling, and the oil and fat agent 1 does not scatter or leak. The amount of oil and fat agent 1 used can also be reduced significantly. Then, by performing heat treatment at a temperature higher than the melting point of the oil and fat agent 1, the melted oil and fat agent 1 is uniformly diffused throughout the strand 4 or the net rope 4' by the action of capillary action of the unimpregnated yarn 3. Because it permeates through the sea, decomposition and deterioration during use in the sea progresses on an average basis, making the net highly safe to use.Moreover, even if it is discarded into the sea at the end of the fishing season, it will be lost in a short time, so the labor and cost involved will be reduced. Not only does it have a significant reduction effect, but it can also be said to be a groundbreaking fence net as it does not pose a risk of interfering with other bottom trawling fisheries. Experimental example Knotted net fabric knitted with a net rope with a diameter of 6 mm using juute hemp and straw rope, and the net fabric impregnated with machine oil, using jujute hemp and straw rope as natural fibers, The invented fence net using grease was used underwater in Sagami Bay for 240 consecutive days.
Table 1 shows a comparison of the rotting and deterioration in terms of changes in strength (reduction in strength) of the mesh ropes.

[Table] As is clear from Table 1, the present invention retains more than 1/3 of its initial strength even after 6 months of underwater use, and is considered to be safe to use during the fishing season. Even if the waste is dumped into the sea, it is expected that it will take another 3 to 6 months for it to disappear naturally.

[Brief explanation of the drawing]

Fig. 1 is an explanatory cross-sectional diagram of a strand, Fig. 2 is an explanatory diagram of a knotless net fabric, Fig. 3 is an explanatory cross-sectional diagram of a strand after heat treatment, and Fig. 4 is a cross-sectional explanatory diagram of a net rope. FIG. 5 is an explanatory diagram of a knotted mesh fabric. Explanation of symbols, 1...Oil agent, 2...Oil impregnated yarn, 3...Unimpregnated yarn, 4...Strand,
4'...Network rope, 4A...Knotless netting, 4B
... Knotted net fabric.

Claims (1)

[Scope of utility model registration request] Strands 4 or net ropes 4' are made of vegetable fiber material and are made of oil-impregnated yarns 2 impregnated with an oil agent 1 that solidifies at room temperature and non-impregnated yarns 3 in an appropriate ratio. A knotted net fabric 4A or a knotted net fabric 4B is knitted, and the oil and fat agent 1 of the oil-impregnated yarn 2 is melted to have a low viscosity,
A fence net characterized by being uniformly diffused and infiltrated throughout the net yarn.