JPS6228404A - Production of pre-oriented monofilament yarn of synthetic material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION In the art of producing synthetic textile yarns, only undrawn and moderately drawn yarns are currently used to produce monofilament yarns.

Up to now, it has not been possible to use predrawn yarns to produce monofilament 1-systems.

The difference between each of the current yarns is the "winding speed" of the yarn, which is extruded from the spinneret in a plastic state (amorphous state), and the "draw grade" (draw grade) added to the yarn.
exists in n a rade).

Such differences are shown in the table below.

Winding speed (TrL/min) Stretching ratio (%) Undrawn yarn 1500 or less 300-400 Medium drawn yarn 1501-2500 200-300 pre-drawn yarn 2501 or more For 20-100 pre-drawn yarn, the yarn winding speed is Due to the large size, the productivity of the machine increases, and when producing yarn using the pre-drawing method, the stretching ratio is small, so the yarn tension (residual stress) generated in the yarn is small. It is known that it is much more advantageous than other yarns, since the number of breaks in the yarn is smaller. This indicates that the yarn produced has a good extrusion amount and a good quality.

Additionally, there is a significant increase in [1] for pre-drawn yarn bobbins relative to similar non-drawn or moderately drawn yarn bobbins.

For some time now manufacturers of synthetic textile yarns have recognized the advantage of using predrawn yarns to produce monofilament yarns. However, to date it has not been possible to obtain yarns of acceptable quality and high extrusion length (i.e., low number of yarn breaks per 100 touches) using pre-drawing methods. Ta.

The present invention provides a simple and effective solution to the above problems,
The predrawn yarns are used to produce monofilament yarns so that synthetic fiber yarns can be manufactured on conventional machines modified as described below with respect to the accompanying drawings.

In Figure 1, a machine used to produce yarns of synthetic fibers such as polyamide, polyester or polypropylene is shown with a spinneret having several calibrated holes (not shown for clarity). It consists of a normal extrusion rate of 1 ending with .

The two or more holes have a diameter ranging from 0.15 to 0.30 m.

The molten plastic material flows through the holes of the spinneret 2 and the amorphous filaments 3 (of which only four are shown) receive a cooling air flow A flowing through the diffusion screen 5. The filaments flow down along the inside of the cooling chamber 4 in which they are placed, cooling the filaments and crystallizing the synthetic material.

Several nozzles 6 (one for each filament bundle) at a predetermined distance below the spinneret, as is known to those skilled in the art.
is arranged to provide the desired amount of spun finish emulsion to each filament bundle.

As known to those skilled in the art, the nozzle 6 is placed above the winder 9 from 5000 to 8000 #ll! The spinneret 2 is located at a distance of 1700 HR from 300 below the spinneret 2, which is installed at a height of .

After being humidified and collected by the nozzle 6, the filament 3 continues to move downward while forming a bundle inside the chamber 4, moves inside the tube 8 as a multificimen l-system 3a, and finally forms a bundle in the tube 8. 8 comes out from the lower end 8a.

Constant speed winder (or other conventional type) winder 9
The multifilament yarn is wound at a speed V of 4000 m/min or more.

FIG. 2 schematically shows a side view of the spinning beam of FIG. 1 and shows an improvement of the invention for producing predrawn monofilament yarns using synthetic materials such as polyamide 6 or polyamide 66. It has points.

The spinneret 2a has an area of 600 to 1000 s2,
It has a single hole (not shown) with a diameter of approximately 0.40 m. The synthetic material is extruded through this hole, giving rise to threads 3b (only three shown), which descend along the inside of the chamber 4 and are cooled in the usual manner by the airflow Δ.

The thread 3b continues to descend through the tube 8 and reaches the lower end 8 of the tube 8.
reach a.

A normal thread guide 7a is arranged at the lower part of the end 8a of the tube 8, and receives the thread 3b and guides it to the corresponding winding bobbin 9.
It is designed to lead to a.

Several tests conducted with this device showed that the humidification of monofilament yarn by the humidification nozzle was
It was found that high quality yarn could not be produced. Tests were carried out by moving the nozzle further from the spinneret, and it was found that adding the finishing emulsion at a position close to the bobbin 9a of the winder, i.e. below the lower end 8a of the machine tube 8, resulted in a rate of 4000 m/min. It has been found that it is possible to produce monofilament yarns, ie predrawn monofilament 1-systems, at winding speeds of more than 1 minute.

The nozzle 6 is conveniently arranged between the lower end 8a of the tube 8 and the position of the thread guide 7a, so that the thread of the predrawn monofilament thread changes direction and enters the bobbin of the winder 9a.

As a result of the tests carried out, the most convenient nozzle 6 for humidifying the pre-drawn monofilament 1-system with the spun finishing emulsion is at a distance of 1500 to 2500 m above the horizontal axis of the winder 9a, i.e. Lower part of the spinneret 25
00 to 6500 m, which was previously considered impossible or impractical in the prior art.

The feasibility and usefulness of the method of the invention can be demonstrated by
○, 25 to BOm with 50M single extrusion hole
When using a spinneret with a diameter of m and using emulsions with oil contents ranging from 4% to 20ml1%, it was found that polyamide 66 as well as polyamide 6 bakayu had high-quality winding speeds of more than 4000 m/min per 100 sieves. It has been shown that predrawn monofilament yarns with a low number of breaks at take-up speeds are obtained.

The table below shows some of the results obtained when producing predrawn monofilament yarns using the method of the present invention using various spinnerets and various distances from the finishing nozzle for the spinnerets. The results are shown below. (about 1
The number of breaks at 6001 m of yarn (of K9) and the (ffii!> ratio of oil in the emulsion) are shown.

[Brief explanation of the drawing]

FIG. 1 is a schematic side sectional view showing a spinning beam of pre-drawn yarns of synthetic fibers according to the prior art. FIG. 2 is a schematic side sectional view of the apparatus of FIG. 1 modified according to the invention for producing monofilament yarn by the predrawing process. 1: extruder, 2: spinneret, 3: filament, 4: cooling seedling, 5: diffusion screen, 6: nozzle, 7a guide, 8: tube, ゛9a; winder,

Claims (4)

[Claims] (1) In a process for producing predrawn monofilament yarns of synthetic material by hot extrusion in a spin beam of the usual type used to produce multifilament yarns, the spin finish is placed at a distance between about 2500 and 6500 mm below the spinneret. A method for producing a pre-drawn monofilament yarn of a synthetic material, characterized in that the monofilament yarn is wound at a winding speed of 4000 m/min or more, and the monofilament yarn produced is of a pre-drawn type. 2. The method of claim 1, wherein the spinneret has an area of about 600 to 4000 mm^2 and the diameter of the extrusion hole is about 0.15 to 0.50 mm. (3) About 4 to 20% by weight of spin oil emulsion
2. A method according to claim 1, comprising an oil of: (4) Pre-drawn monofilament yarns of synthetic materials such as polyamides, polypropylenes, etc., the yarns being produced by the method described in any one of the above claims.