JPS6366315A - Production of acetate thick yarn - Google Patents

Abstract

PURPOSE:In dry spinning of acetate yarn, to obtain the titled fine, slub-shaped yarn having extremely clearly produced difference in unevenness, by reducing spinning take-off speed intermittently while satisfying a specific condition. CONSTITUTION:In obtaining acetate yarn by dry spinning, spinning take-off speed is intermittently reduced in such a way that the formulas V0/V1>1.5 and T120/V0 [V0 is spinning take-off speed (m/min); V1 is spinning take-off speed at reduced rate (m/min); T is continuous time of low speed spinning (sec)] (m/min)] are satisfied to give the aimed acetate thick yarn. The intermittent reduction in spinning speed, for example, is carried out by using a take-up roll 3 equipped with a groove having depth A0-A1 at theta angle and moving a guide 5 left and right round the groove of the roll 3. In this case, A0/A1>1.5 and theta<=180 deg.C are preferable and a guide 5 is preferably moved in a random period.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing thick and thin acetate threads.

[Conventional technology]

Conventionally, a large number of methods have been developed and provided for thick and thin threads, particularly for polyester. In the case of these polyester fibers, in general, the undrawn yarn is stretched under specific stretching conditions to cause the necking phenomenon. Detailed studies have been conducted on how to stabilize quality, and many technologies have been put into practical use.

[Problem that the invention seeks to solve]

However, the reality is that no practical method has yet been found for acetate yarn. This is because in dry spinning of acetate, most of the fibers are formed immediately after the raw solution is discharged from the spinning nozzle, so there is no intermediate product of undrawn yarn like in the case of polyester mentioned above, and from now on, This is because no further stretching operation is possible.

The first object of the present invention is to provide a stable method for producing thick and thin dry acetate yarns, and the second object is to provide a more effective method for producing thick and thin yarns.

[Means for solving problems]

The present invention provides a method in which a predetermined spinning take-off speed ["o (m7 minutes)] in a dry spinning method of acetate yarn is intermittently reduced to a low speed [VI
(m15+) ] to produce thick and thin yarn, 5vo/
v, ) 1.5 and T < 120/VOC However,
This is a method for producing thick and thin acetate yarn, characterized in that T is V, and the duration (seconds) is satisfied.

The present invention will be explained in detail below.

Dry spinning of -ff acetate involves dissolving the flakes to prepare a spinning stock solution, which is then discharged into heated air from a small-pore spinneret to evaporate the solvent and form yarn. When the yarn is discharged from the spinneret, a considerable amount of the solvent on the surface layer evaporates in an extremely short period of time, and most of the fiber formation is completed within a few centimeters directly below the spinning nozzle. It is said that there are almost no major changes in the thread structure during the long thread travel process.

The present inventors have arrived at the present invention by effectively utilizing these characteristics of dry spinning. It is characterized by obtaining a large system part by slowing down the speed.

As mentioned above, in dry spinning of acetate, most of the solvent evaporates in the instant immediately below the spinning nozzle, so the stretching in so-called spinning is considered to be tiJ only in a short section. The thickness of the yarn is determined by the spinning stock solution (or the amount of yarn) present between the spinning nozzles and the pulling speed (take-up roller speed) at that time. Therefore, when the discharge amount from the spinneret is kept constant, if the take-up speed is slowed down by the amount of time it takes, a thick yarn portion of a certain length will be formed depending on the time.

The inventors of the present invention have extensively studied this speed reduction and have found that it is possible to effectively produce thick and fine yarn within the range below, without making it compatible with the surface design effect of the product fabric.

That is, take-off speed when forming the thin thread portion: V6 (m7 minutes)
Take-off speed when forming thick yarn part: VI (m/1A-)
Then t5ku-V.

In addition, we found that it is possible to form a large system with excellent product effects when the vl duration T (sea) is within the range of T(- O.On the other hand, the cycle of reducing the take-up speed is basically Although it is important for product quality to occur randomly, there is no particular restriction on the frequency as it has no effect on the formation of thick threads.

Therefore, by appropriately determining the frequency of occurrence based on the product appearance,
Thick and fine yarn with extremely high appearance design effects can be produced.

The method of the present invention will be specifically explained below.

FIG. 1 shows an outline of the entire manufacturing apparatus of the present invention.
1. are spinning nozzles, 2 drying tubes, 5 take-up rollers, 4
4 shows a winding device, 5 a guide, & an oil supply section, and FIG. 2 shows a schematic diagram of a take-up roller used in the present invention.

As shown in FIG. 2, a part of the take-up roller with a diameter AO is provided with a groove having a depth of Ao −A, ) at an angle θ in the circumferential direction, and the yarn guide 5 of FIG. It can be moved left and right around the groove of this take-up sheet roller.

With the device described above, the yarn discharged from the spinning nozzle is taken up by the take-up roller and wound up. By moving the guide left and right around the groove of the roller, the take-up position of the yarn on the roller can be adjusted. The thread traverses from side to side, temporarily falls into the groove, and is taken up. Since the surface speed of the groove is lower than that of the non-groove area, a large system part is formed while the thread is falling into the groove. .

Therefore, as the depth of this groove increases, the difference in fineness between the fine thread part and the large thread part increases, especially -A->1.5
is the desired A in terms of demonstrating the product appearance effect! Delicious.

In addition, the angle θ is set according to the groove Ao-Al according to the present invention.
) is equally important. In other words, as the angle increases from θ=0, the length of the groove provided on the roller becomes longer.
Therefore, the length of the main part becomes longer, but in the present invention, the grooves do not completely cover the entire circumference of the roller, that is, the grooves are partial and a part of the groove layer is on the surface of the roller in the non-grooved area. The important point is that it is on the same plane as θ≦
Approximately 180° is preferable. This is to ensure that the yarn taken in the groove-carrying section escapes from the groove as the yarn guide 5 moves, and this allows the yarn between the groove and the non-groove section to be connected even if the depth of the groove is short or deep. sD can be performed stably and smoothly.

Moreover, as a result of this, the length of one large section is naturally restricted, and this can be determined by taking into account the diameter of the take-off roller and the required large section. There are no particular restrictions on the method of moving the yarn guide 5, and it may be mechanical or electrical, but it is essential for the quality of the product to be able to move back and forth at random intervals.

〔Example〕

Triacetate bright filament 10 under the following conditions
0d/26f was spun.

(1) Take-off roller specification 80 = 1031! y + AI- = 52 + m θ = 0.90, 180° (3 types) d -10 (2) Other spinning conditions Take-up roller rotation speed: 460 rpm Yarn guide movement period (one way): [16 ~ 1.0 sec (3) )
Spinning results *1 The results were as expected for the length of the single chassis, which produced a thick yarn effect, and there was almost no yarn breakage under each condition, and the spinning stability was good. In addition, the knitted products and knitted products made of these yarns had large-scale portions clearly appearing on the surface of the fabric as convex portions and knots, and had a delicate slab-like appearance, which was very preferable.

〔effect〕

As described above, the present invention is capable of producing thick A yarn in a practical and extremely stable manner as dry spinning, and the effect on the product appearance is that the difference in unevenness is better than that of most conventional thick and thin yarns. It appears that the significance of the present invention is in dogs, as this occurs very clearly.

[Brief explanation of drawings]

Fig. 1 is a side view showing an example of a device used for carrying out the present invention, Fig. 2 (a) is a front view of a take-up roller in the device of Fig. 1, and Fig. 2 (b) is a side view thereof. . (Re) Spinning nozzle (2) Drying cylinder (3) Take-up roller (4) Winding device (5) Guide guide (6) Oil supply section diagram + 2 (A) (B)

Claims (1)

[Claims] When producing thick and thin yarn by intermittently reducing the predetermined spinning take-off speed [V_0 (m/min)] to a low speed [V_1 (m/min)] in the dry spinning method of acetate yarn, the formula V_0/V_1>1
．． 5 and T<120/V_0 [where T is the duration of V_1 (seconds)].