JPH0117172Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to net fabric for fixed fishing nets.

Fixed nets mainly target migratory fish, so the location where they are set has relatively fast currents.
Moreover, they are usually placed in sea areas with a depth of 30 to 100 meters. The nets constituting the fixed net are suspended on one side by a frame body having a predetermined shape, which is a so-called side line, which is suspended on the sea surface by a large number of floats, and the nets are suspended on one side by their own weight and any part of the net. Since the net is suspended and expanded by the settling force of the sediments interposed in the net, the expanded shape is easily deformed even by a slight resistance to the tidal current, and at times of rapid tide or waves, the resistance to the tidal current increases and the hem of the net becomes A so-called blown-up phenomenon occurs, which significantly impedes the effects of intimidating, guiding, trapping, etc. on migratory fish schools, often resulting in the inability to catch fish.

For these reasons, net fabrics for fixed fishing nets are desired to have a relatively heavy net weight, with a specific gravity of at least about 1.6 to 2.5.For this reason, it has traditionally been the heaviest of synthetic fibers, with a specific gravity of approximately 1.7. A fabric made of polyvinylidene chloride synthetic fibers having the following properties was used.

However, this net fabric is inferior in toughness, and net breakage accidents frequently occur due to increased tidal current resistance due to sudden tides and waves, and collisions with floating objects, etc., and the cost and labor involved in repairing these accidents is enormous. It was hot.

Due to this background, in the current fixed nets, the toughness is about 3 to 3 times stronger than that of conventional polyvinylidene chloride synthetic fibers, and the network made of polyester fibers that are about 2 to 3 times stronger. Net fabrics made by knitting approximately 40 to 60% of polyolefin synthetic fibers such as polyethylene and polypropylene, which are four times as strong as polyethylene and polypropylene, are being replaced. % weight of the net becomes lighter, and when expanding the net, it is necessary to interpose an additional 20 to 30% of precipitated material such as metallic chain or lead precipitate in the required middle part or hem of the net. arise. However, if the settling force associated with the stretching of the net is caused by the net's own weight, the net will have openings with a predetermined shape because it will be distributed over the entire net, but the settling force of the settling material will be There is a tendency to act in a direction approximately perpendicular to the buoyancy force of the side line located on the sea surface side, and the mesh portion of the net fabric to which the settling force is applied by the settling material is elongated up and down, and on the contrary, it may block the mesh. This causes non-uniform mesh openings throughout the area, which is a new cause of the blowing phenomenon. There are many problems that hinder the net lifting work.

The present invention provides a net fabric for fixed fishing nets that solves this problem.The embodiments of the present invention will be described below in detail based on the drawings. Figure 1 is a front view of the half-open knotted net fabric of the present invention. Fig. 2 is a cross-sectional explanatory diagram of the mesh yarn, and Fig. 3 is a cross-sectional explanatory diagram of the high specific gravity net yarn.
Knotted net fabric 1 is made by knitting net yarn 2 made by twisting synthetic fibers to a desired thickness into main knots or frog knots in a desired mesh size, and the knotted The net yarn 2 constituting the net fabric 1 is made of two strands 2A made by twisting synthetic fibers as shown in FIG.
The synthetic fibers 2B constituting the strands 2A are desired to be strong and have as large a specific gravity as possible, so at present, polyester synthetic fibers or polyvinylidene chloride synthetic fibers are combined with polyolefin synthetic fibers. Fiber is 40~
Since a 60% mixed twist is used, the specific gravity in the state of the mesh yarn 2 is substantially set in the range of 1.1 to 1.4. Then, meshes 3A, 3B, 3C, . . . or 3A', 3B', 3C', . The portion corresponding to the half stitch is composed of high specific gravity mesh yarns 4, 4'. These high specific gravity net yarns 4 and 4' have a specific gravity of 50~50 compared to the net yarn 2.
It maintains 100% high specific gravity, and the high specific gravity net yarn 4,
As shown in FIG. 3, 4' is formed by mixing and twisting a high specific gravity substance 5 made of lead wire, lead powder, iron powder-filled wire, etc. and synthetic fiber 2B in an appropriate ratio.

In cases where a large net weight is required, such as a net laid in a sea area with fast currents, the net is knitted so that the high specific gravity net yarns 4, 4' are arranged at close intervals.

FIG. 4 shows a front view of the knotted mesh fabric of the present invention, which shows cases in which the net weight of the fabric is increased, and when the high specific gravity mesh yarns 4 and 4' have hardness and In cases where rigidity is imparted, the high specific gravity mesh yarns 4, 4' are arranged in a single stitch to prevent the flexibility of the mesh fabric from being impaired.

FIG. 5 shows an explanatory front view of the half-knot knotless net fabric of the present invention, and a net fabric with a similar configuration can also be formed by using a lattice knitted net.

The present invention has the above-mentioned configuration, and includes a net fabric for fixed fishing nets knitted with or without knots using synthetic fibers, in which the specific gravity of the net threads constituting the mesh of the net fabric is 1.1. -1.4, and each half or one stitch of each mesh belonging to the same vertical or horizontal row of the mesh has a specific gravity that is 50 to 100% larger than that of the threads constituting the other meshes. Since it is composed of mesh threads, the settling force of the high specific gravity mesh threads diffuses over the entire mesh fabric along the mesh threads of the mesh, so the mesh is kept open evenly without being stretched, allowing for good drainage. Not only is the specific gravity of the high-density mesh yarn compared to the specific gravity of the leg rope,
Since the increase is within the range of 50 to 100%, there is no fear that the sedimentation force of the high specific gravity mesh yarn will deform the mesh.

Moreover, since the high specific gravity net yarn is knitted without any difference from the net yarn, the flexibility and stretchability of the net fabric can be fully demonstrated, and the bulk of the net fabric is greatly reduced, making it easy to carry out net-lifting and transportation work. It can be said that this net fabric for fixed fishing nets has excellent features such as significantly improved properties.

[Brief explanation of the drawing]

Fig. 1 is an explanatory front view of the half-open knotted net fabric of the present invention, Fig. 2 is an explanatory cross-sectional view of the mesh yarn, Fig. 3 is an explanatory cross-sectional view of the high specific gravity net yarn, and Fig. 4 is an explanatory view of the cross section of the present invention. FIG. 5 is an explanatory front view of the knotless mesh fabric with a half mesh structure according to the present invention. Explanation of codes, 1... Net fabric, 2... Net yarn, 2A...
...Strand, 2B...Synthetic fiber, 3...Mesh,
4...High specific gravity net thread, 5...High specific gravity substance.

Claims (1)

[Scope of utility model registration request] Polyolefin synthetic fibers are added to polyester synthetic fibers or polyvinylidene chloride synthetic fibers.
A high specific gravity net yarn made by mixing and twisting a net yarn with a specific gravity of 1.1 to 1.4 that is 40 to 60% mixed and twisted, and a synthetic fiber and a high specific gravity substance so that the specific gravity is 50 to 100% higher than the specific gravity of the net yarn. A net fabric for a fixed fishing net, characterized in that half or one stitch of the mesh in any same column or row of the net fabric knitted with the above-mentioned high specific gravity net yarn.