JPH0125564Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial field of application> This invention relates to a knotted end for seine nets that eliminates twisting.

<Conventional technology and its problems> In general, bottom trawl nets come in various sizes, but in recent years, there has been a trend to increase the size of the trawled ends in order to increase the horsepower of fishing boats or to improve operational efficiency. However, the width of the knotted end in the transverse direction to the seine direction cannot be increased unnecessarily due to the restriction of the slipway width of the ship, so in order to increase the carrying capacity, it is necessary to lengthen the knotted end in the seine direction. Designed. In the case of small-scale bottom trawl nets, a single layer of net fabric of the same standard is used.
In order to increase the carrying capacity of knitted ends, a net with high strength, that is, a net with a large diameter, is required, but on the other hand, there is a limit to the netting capacity of the knitting machine, so it is not possible to make the net thicker without limit. figure. In order to meet the required strength of the knotted ends, double or triple layers of net fabric of the same standard are used. However, although the netting is made with double or triple layers,
Both of these use net fabrics with the same twist direction, and the knotted ends of conventional seine nets are generally polyethylene knotted nets or knotless nets, but the net legs of these nets are Since all of these are twisted in the same direction, even though the twist is fixed by heat treatment after the knitting, the 100
% twist fixation is difficult, and since torque always remains, it has the disadvantage that the knotted ends tend to twist in the twisted direction. Therefore, the torsion is further amplified by the action of the current, the shock when the net lands on the bottom during trawling, or the external force received when it comes into contact with a rocky reef, sometimes causing a 180 degree twist in the knotted end, and from then on the knotted end returns to its normal position. If operations were carried out without restoring the net, problems such as broken nets and deformation of the mesh due to the pressure of fish entering the trapped end, and even broken nets around the trapped end occurred.

Therefore, the net used for knitted ends is required to be resistant to twisting, regardless of whether or not heat treatment is applied after the knitting. 55−
There is one described in Publication No. 96188.
However, regarding the mesh fabric described in the same bulletin,
Right-twisted yarn and left-twisted yarn coexist in the same net fabric, and there are also knots made of right-twisted yarn and left-twisted yarn,
In this case, although twisting is certainly prevented overall, twisting occurs partially in the right-twisted yarn part to the right and in the left-handed yarn part to the left, resulting in The entire net fabric has a wavy, uneven shape. Moreover, using a knitting machine to knit a net fabric that has net legs with different twist directions not only leads to a decrease in the efficiency of the knitting network, but also makes the design of the knitting machine itself very difficult. It is clear that this is difficult.

<Means for solving the problem> Therefore, in order to solve the above-mentioned problem, the twisted end of the seine according to this invention has a structure in which either the upper surface or the lower surface of the twisted end body is twisted in the S direction. This is a twisted knitted fabric, and the other is made of a netted fabric in which the first twist is twisted in the Z direction, so that the mutual twisting effects are offset or reduced.

<Embodiment> Next, an embodiment of the knotted end of the seine net according to the present invention will be described based on the drawings. In FIG. teeth,
Either one of the upper surface part or the lower surface part is made of a knitted fabric with a top twist of S, and the other part is made of a knitted fabric with a top twist of Z. That is, the upper surface portion 3 of the knotted end main body 1 is made of, for example, an S-twist knitted fabric, and the lower surface portion 4 is made of a Z-twisted knitted fabric. The upper surface part 3 and the lower surface part 4 may be made of single-ply fabric with different twist directions, but may also be made of double or triple-ply fabric. In the case of double or triple layering like the latter, the outer mesh and the inner mesh do not have to be of the same diameter (or denier); for example, the legs of the outer mesh can be made of 450 pieces of polyethylene 400d. ,
Even when the net legs of the inner net fabric are double-lined with 300 polyethylene 400d fibers, the twisting direction of all these net legs is the Z direction to the upper surface part 3, and the twisting direction of all these legs is the S direction to the lower surface part. Any net can be used as long as it can be arranged in 4 layers and reduce the mutual twisting effect.

When using double fabrics, one of the two fabrics on the top side is twisted in the S direction, the other is twisted in the Z direction, and one of the two fabrics on the bottom side is twisted in the S direction. It is also possible to use one sheet with the first twist in the S direction and the other one with the second twist in the S direction.

Regarding the twist direction, for example, if heating is performed in three stages: first twist (number of twists: A times/m), middle twist (number of twists: B times/m), and final twist (number of twists: C times/m),
The number of yarns constituting the net legs is the same and the ply twist is S.
The directions and number of twists for the lower twist, middle twist, and upper twist of the net legs are S (A times/m) and Z (B times/m), respectively.
m), S (C times/m), and the directions and number of twists of the lower twist, middle twist, and upper twist of the net leg with the first twist in the Z direction are Z (A times/m) and S (B times/m), respectively. /m), Z(C
times/m), and these two net fabrics with different twist directions are used for the upper surface part 3 and lower surface part 4 of the knotted end, respectively, to make the knotted end. That is, at each twisting stage, the net legs are made with the same number of twists in opposite directions.
If the number of raw threads is different, only the number of twists may be changed appropriately to obtain an appropriate net leg.

Even when the knotted end has both side parts 5 and 6 as shown in Fig. 2, it is possible to completely prevent twisting by sewing fabrics with opposite twist directions. Since this occupies a small proportion of the knotted ends, it may be practical to use net fabric twisted in the same direction as long as the twist of the whole knotted ends can be reduced.

<Effects of the invention> As described above, according to the knotted end of the seining net according to this invention, either the upper surface or the lower surface of the knotted end main body is made of S-twisted knitted net, and the other is made of Z-twisted netting. Since it is made of a twisted and knitted net fabric, it has the effect of being less likely to twist during seine fishing and ensuring stable operations.

[Brief explanation of the drawing]

The drawings show an embodiment of the knotted end of the seine according to this invention, and Fig. 1 is a perspective view;
FIG. 2 is a perspective view showing another example. 1...Kotted end body, 2...Trawling net, 3...
. . . Upper surface of the knuckled end body, 4: Lower surface portion of the knuckle end main body, 5, 6: Both sides of the knuckle end main body.

Claims (1)

[Scope of utility model registration request] Of the top or bottom part of the knuckled end body,
A knitted end of a seine net characterized in that either one of the two is made of a knitted fabric with the ply twisted in the S direction, and the other is made of a knitted fabric with the ply twisted in the Z direction.