CS273920B1 - Method of polyamide monofilaments preparation for angling lines - Google Patents

Abstract

The preparation of polyamide monofilaments for fishing lines is achieved by fibre formation of polyamide melts, when fibrous monofilaments are cooled down by water to the temperature lower than 35 degrees, whereupon they are immediately drawn in two stages, while the temperature in the second stage does not exceed the temperature in the first drawing stage by 30 degrees and monofilaments are maximally drawn by 20 percent in the second drawing stage, whereupon drawn monofilaments are exposed to effects of agitate air with the temperature between 100 and 150 degrees in order to contract monofilaments by at least 4 percent.

Description

The present invention relates to the preparation of polyamide monofilaments for fishing lines.

Monofilament lines based on polyamide monofilaments with a diameter of 0.1 to 1.5 mm are predominantly used for sport fishing. Monofilament fishing lines shall be characterized by high strength, knot strength, shock resistance, and at the same time they shall be sufficiently flexible and supple. Therefore, in many cases, copolyamides or softener additives are used to make softened fishing lines. However, this often leads to a reduction in line strength. To obtain high strength monofilament lines, a high molecular weight polyamide is often used, i.e. a polyamide that is used to produce cord silk. This process has the disadvantage that the monofilaments produced are often rigid and not flexible.

A disadvantage in terms of achieving optimal monofilament properties for fishing lines is also low molecular weight polyamide 6, i.e. polycaprolactam, which is used for the production of textile silk. Conventionally, either a low-strength, low-knot monofilament or a flexible, low-strength, flexible monofilament may be prepared from this low molecular weight polyamide 6. Both procedures are not advantageous for fishing practice.

The molecular weight of the polyamide can be characterized by a relative viscosity value. When measuring the relative viscosity in a 1: 3 phenol-tetrachloroethane mixed solvent, the relative viscosity of the low molecular weight polyamide 6 for textile purposes is in the range of 1.5 to 1.65. For technical cord silk polyamide, the relative viscosity value in this measurement is in the range of 1.7 to 2.

Monofilaments are produced by spinning the demonomerized polyamide 6 melt using a circular orifice spinneret. The fiberized monofilaments are then stretched at normal or elevated temperature and wound onto coils. For the production of monofilaments, universal production lines are used, consisting of an extruder, a dosing pump, a spinning block with a nozzle, a cooling tub, exhaust and drawing units, heating drawing zones and a winding machine.

The properties of the resulting monofilaments such as strength, knot strength, shock load resistance, initial modulus, elasticity, suppleness, ringing in unwinding from the spool have, in addition to the starting material, also the conditions of its production. By suitably selecting the conditions for its preparation, the properties of the monofilaments can be favorably influenced with respect to its application.

The above drawbacks in the manufacture of polyamide monofilaments for fishing lines of 0.1 to 1.2 mm in diameter by spinning a demonomerized polyamide 6 melt of relative viscosity

1.5 to 1.7 and subsequent two-stage hot-air drawing to a drawing ratio of 4 to 5.5 are removed using the process for their preparation according to the invention, characterized in that after spinning the monofilaments are cooled with water to a temperature below 35 ° C and then immediately drawn in two steps such that the temperature in the second drawing step does not exceed the temperature in the first drawing step by 30 ° C and in the second drawing step the monofilaments are stretched by at most 20X and subsequently the elongated monofilaments are exposed to 100 ° C to 150 ° C to shrink them by at least 4%.

The polyamide monofilament prepared by the process of the present invention exhibits a sufficient single knot strength value at an acceptable strength level and reduced ring formation when the line is unwound from the spool. The line thus prepared exhibits substantially improved performance in practical sport fishing than a monofilament produced under normal conditions. The monofilament line prepared by the process of the invention is at a relative knot strength greater than 50 X, more resistant to shock loading by 25 X than the line prepared under conditions outside the stated temperature range and stretching ratios.

The production of monofilaments according to the invention can be carried out on conventional extruder lines for the production of monofilaments. Optimal choice of distribution of stretching ratios in individual parts of extruder line at defined temperature ratios allows suitable formation of supramolecular structure

C S 273 920 B1 of monofilament, which then has a beneficial effect on the performance properties of monofila in sport fishing.

The invention is illustrated by the following examples.

Example 1

A melt of demonomerized polyamide 6 containing a green dye having a relative polyamide viscosity of 1.63 was spun at 232 ° C. The fiberized monofilaments were cooled with water to 27 ° C and then immediately drawn in the first stage of the production line at a draw ratio of 4.33 and 192 ° C and then in the second stage at a draw ratio of 1.09 and at 215 ° C. The two-stage elongated monofilaments were then immediately exposed to the flowing air at 115 ° C with the possibility of shrinking by 6%. Properties of prepared monofilaments ·: diameter 0.26 mm, strength 40N, single knot strength 22N, initial modulus 4, B GPa. The monofilament withstood without a break the tethered weight of 180 g from a height of 1 m.

Example 2

The melt of demonomerized polyamide 6 having a relative viscosity of 1.6 was spun at a temperature of 235 ° C. The fiberized monofilaments were cooled with water to 30 ° C and then immediately drawn in the first stage of the production line at a draw ratio of 3.78 and a temperature of 205 ° C and then in the second stage of the production line at a draw ratio of 1.12 and at 220 ° C. The two-stage elongated monofilaments were then immediately exposed to the flowing air at 130 ° C with the possibility of their shrinkage by 8 X. Properties of prepared monofilaments: diameter 1.15 mm, strength 480 N, elongation 26%, single knot strength 260 N, relative knot strength 55%

The polyamide monofilament lines produced according to the invention can also be used for the production of sieves, nets, zippers and strings.

Claims (1)

Process for preparing polyamide monofilaments for fishing lines of 0.1 to 1.2 mm diameter using melt spinning of demonomerized polyamide 6 with a relative viscosity of 1.5 to 1.7 and subsequent two-stage hot-air drawing to a draw ratio of 4 to 5.5, characterized by in that after spinning the monofilaments are cooled with water to a temperature lower than 35 ° C and then immediately drawn in two steps whereby the temperature in the second drawing step does not exceed the temperature in the first drawing step by 30 ° C and in the second drawing step 20X and subsequently the elongated monofilaments are exposed to flowing air at a temperature of 100 ° C to 150 ° C to shrink the monofilaments by at least 4X.