JPS5818460B2 - twine for fishing nets - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a twine, and an object of the present invention is to obtain a twine that has various performances required for fishing nets and has low bending stiffness.

As the performance that a fishing net should originally have, (1) High strength and impact resistance.

(2) It must have an appropriate specific gravity.

(3) The bulk is small. (4) Excellent wear resistance.

(5) The performance of (1) to (4) remains unchanged even after long-term use.

etc. have been requested.

Among fishing nets, polyamide synthetic fibers with excellent strength, impact resistance, abrasion resistance, and durability have been mainly used in the field of gill nets and purse nets in the form of monofilament and multifilament twisted yarns.

However, from the viewpoint of net structure, sedimentation properties, and net weight,
The specific gravity of the net suitable for gill nets and purse nets is 1.30 to 1.40.
Since polyamide-based synthetic fibers have a low specific gravity, they have not been particularly suitable for use in purse purses.

Furthermore, when comparing conventional monofilament fishing nets and multifilament fishing nets, monofilament fishing nets have a rigid net fabric and are suitable for gillnet applications, especially in that the net formation required in the water, but Therefore, when the net fabric is folded, the overhang of the net fabric is large.
It also has the disadvantage of poor fabric handling properties.

On the other hand, fishing nets made of multifilament have low rigidity, so they are excellent in that the bulk of the net is small, but the disadvantage is that the rigidity is too low and the net does not have adequate elasticity. Moisture is contained between the fibers inside the net, and even after the net is lifted onto the ship, the contained moisture does not come out easily.
The disadvantage is that the weight of the net is thick.

Therefore, as a conventional method to increase the specific gravity of polyamide synthetic fibers and to make them less rigid than monofilament fishing nets, multifilament polyamide synthetic fibers and heavy metal threads with a higher specific gravity are mixed and twisted, and polyamide A method has been used to compensate for the lack of specific gravity in synthetic fibers with heavy metal threads, and to reduce the stiffness of the twine by twisting multifilament threads.

However, polyamide synthetic fibers and conventional heavy metal yarns have different characteristics such as fiber strength, dyeing, and shrinkage.
Fishing nets made from twine after twisting using the conventional method have different dyeing properties and heat shrinkage differences between polyamide fibers and heavy metal threads.
The net had a poor appearance (the diameter of the net legs was large, and the fishing net was of poor quality).

The present invention takes advantage of the advantages of polyamide synthetic fibers, has appropriate specific gravity, appropriate stiffness, and has low net bulk.
Moreover, it was obtained as a result of intensive research to obtain fishing nets with good drainage.

That is, the present invention provides twine for fishing nets made by pliing and twisting heavy metal threads coated with a polyamide synthetic resin, having a specific gravity ρ of 1.30≦ρ≦1.50, and a single filament fiber count of 50 to 200 deniers. It is in.

Here, heavy metal thread refers to a thread whose core is made of a heavy metal with relatively high specific gravity and whose outer side is covered with polyamide-based synthetic resin. Heavy metals used for the core include, for example, lead, tin, and their like. Alloys are preferred, and lead alloys are most preferred because of their high specific gravity.

Such polyamide-based resin-coated heavy metal threads include:
There are those in which heavy metal threads are coated with polyamide resin such as nylon 6 and 66, and those in which a heavy metal is used as a core and the polyamide resin is used as a sheath by melt-spinning using a known core-sheath type composite spinning technique. The latter core-sheath composite fiber is preferred.

In the case of such a composite fiber-type polyamide-based resin-coated heavy metal thread, the heavy metal in the core may be cut and become discontinuous when drawn, but such a core-sheath type composite fiber may be used.

The details of the present invention will be explained below with reference to the drawings.

FIG. 1 shows a schematic diagram of a twine obtained according to the invention.

In FIG. 1, a twine 1 is made by twisting a plurality of heavy metal threads 2 together.

Conventional heavy metal yarns have been mixed and twisted with polyamide fibers in order to make the specific gravity of the twine suitable for gill nets and purse nets, that is, 1.30 to 1.50. It was necessary to increase the proportion of heavy metals.

The outer periphery of the heavy metal core may be coated with nylon 6 or 66, or the core may be made of heavy metal and the sheath made of nylon 6.66.
Heavy metal yarns obtained by composite spinning, etc., become difficult to draw during spinning as the proportion of heavy metals in the core increases, and they tend to break easily during drawing. (The strength is low because it is drawn at a relatively low magnification or heavy metal thread is not drawn.
There was wide variation in strength (and there was also large variation in single yarn diameter.

Furthermore, because the fiber properties of conventional heavy metal yarns are different from those of polyamide synthetic fibers that are twisted, fishing nets made from twisted twine have poor appearance due to uneven dyeing, uneven heat shrinkage, etc. Special treatment methods were required to improve the appearance of the ground.

On the other hand, since the heavy metal yarn 2 used in the present invention has a specific gravity of 1.30 to 1.50 as a single yarn, it is not necessary to intertwist the heavy metal yarn 2 with the polyamide synthetic fiber.

Therefore, the problems caused by the above-mentioned twisting can be avoided, and the proportion of heavy metal in the cross-section of the heavy metal yarn 2 can be significantly reduced, so that it is almost the same as ordinary fibers made only of nylon 6.66, etc. Similarly, since high-strength stretching is possible, a twine with high strength can be obtained.

In addition, if this twine is made into yarn and made into a net, a fishing net of excellent quality can be obtained.

In addition, in Fig. 1, the heavy metal yarn 2 is made by suitably twisting yarns with different specific gravity, single yarn fineness, and single yarn diameter, and has a twine specific gravity,
Although it is possible to change the twine bending stiffness, it is preferable that the single yarn diameters be the same from the viewpoint of twine appearance.

In addition, the fineness of the single yarn must be between 50 and 200 deniers; if it is less than 50 deniers, it will be difficult to spin the yarn, and if it exceeds 200 deniers, the bending stiffness will be too large, making it difficult to The performance is similar to that of a monofilament fishing net, and a fishing net of excellent quality cannot be obtained.

The twine obtained by the present invention has almost the same strength, impact resistance, durability, abrasion resistance, etc. as the conventional polyamide synthetic fiber twine, and the specific gravity is thicker than the polyamide synthetic fiber. The latter net has a good appearance and is much smaller in bulk than conventional monofilament fishing nets.Furthermore, the bulk of the net is almost the same as conventional fishing nets made only of multifilament, and it has a lower back than conventional fishing nets made of multifilament. It is suitable for gill nets, purse nets, and fixed net lengths.

Examples according to the present invention will be described below.

Example 1 A lead alloy with a specific gravity of 11.0 as a core and nylon 6 as a sheath were melt-spun by core-sheath type composite spinning, and the fiber cross-sectional area ratio of lead alloy and nylon 6 was 1:60. Specific gravity is 1.30, single yarn fineness is 200 denier, and number of single yarns is 19.
This polyamide-coated heavy metal yarn was prepared.

This heavy metal yarn has a twist coefficient K of 160 (1) when twisting downward; the three obtained lower twist threads are placed into a stand system, and the number of twists when twisting upward is 0.54 of the number of downward twists. Twisted as a double,
A tow-in with a diameter of 0.9 m and 711 was obtained.

The bending stiffness of this twine was 6.6.

On the other hand, the bending stiffness of a conventional polyamide synthetic fiber monofilament with a diameter of 0.9 mm is 182.0? So, the bending stiffness of the conventional polyamide synthetic fiber multifilament 210 denier, 7 filament 5 x 3 twine is 1.5'f!
Met.

Here, the bending stiffness is defined as using a handling tester, placing the center part of a sample with a sample length of 3 crn on a metal hook attached to a metal resistance wire strain meter, and bending the inner diameter of 1 crn at a speed of 30 cm/min.
The resistance of a sample passing through the ring was measured ten times or more by moving a metal ring at a distance of 0.5 degrees, and the average value was shown.

From these results, it can be seen that the twisted twine according to the present invention has a significantly lower bending stiffness than the conventional monofilament, and has a higher bending stiffness than the conventional multifilament twine.

[Brief explanation of drawings]

FIG. 1 shows a schematic diagram of a twine according to the invention. [Explanation of symbols], 1: Combined twist twine, 2: Heavy metal yarn.

Claims (1)

[Claims] 1 Covered with polyamide synthetic resin and with specific gravity ρ
is 1.30≦ρ≦1.50. Twine for fishing nets made of heavy metal threads with a single yarn fineness of 50 to 200 deniers.