JPS5926509A - Spinning in upward counter flow bath - Google Patents

Abstract

PURPOSE:To obtain a yarn product free from end breakage industrially stably, using a flow pipe having specific conditions, spouting a coagulating solution sent from the flow pipe into the air intentionally, carrying out the spinning, so that the physical properties of the yarn are kept well. CONSTITUTION:First, a spinning stock solution introduced from the feed pipe 4 for the spinning stock solution is extruded from the spinneret 6 to acoagulating bath. As it is formed into the semicoagulated filaments 7, it together with the coagulating solution 9 is passed through the inside of the flow pipe 8 having a slant degree theta to the perpendicular 11 on the surface of the earth. The coagulating solution 9 is then intentionally spouted from the outlet of the flow pipe 8 into the air by sending it forcedly by a pump, etc., the stock solution is completely coagulated while it is passed through the spouting coagulating solution 9, so that the coagulated yarn 10 is obtained at the peak of the spouting coagulating solution 9. The slant angle theta is preferably 5-20 deg.. EFFECT:The unevenness of the physical properties of the yarn is reduced. Suitable for high-speed spinning.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved upflow bath spinning method for producing yarn by a wet spinning method.

Wet spinning dope such as viscose is
It is discharged through a spinneret into a coagulation bath.

After being coagulated, it is pulled out from the bath and formed into a thread, which is then subjected to post-treatment as required to become a product thread.

Conventionally, in order to increase the spinning speed to increase productivity, a number of fluid bath spinning methods have been proposed in which the coagulation bath is made to flow in the same direction as the running direction of the spun yarn.1 For example, the viscose method In the method for manufacturing rayon yarn according to 1
The spinning method described in Japanese Patent Publication No. 27-4931 is well known. Furthermore, for example, Japanese Patent Publication No. 30-8866, Japanese Patent Publication No. 31-5963, 1% Publication No. 34-6058
An upflow bath spinning method as described in Japanese Patent Publication No. 38-3956 has been proposed, and it has the following advantages: This is a favorable improvement in that the gas generated during spinning does not accumulate on the spinneret surface.

However, all of the upstream bath spinning methods that have been proposed so far have been designed to maintain the physical properties of the raw yarn at a good level and to minimize unevenness in the physical properties, especially in high-speed spinning. No method has yet been found that simultaneously satisfies the conditions of significantly reducing process defects such as thread breakage and fuzz.

For example, Special Publication No. 31-5963 or Hanko Publication No. 34
In Publication No. 6058 or Japanese Patent Publication No. 38-3956, the coagulation bath flowing out from the outlet of the flow tube is received in an overflow receiving tank larger than the outside diameter of the flow tube, or is gradually and continuously directed toward the outlet of the flow tube. By increasing the inner diameter of the flow tube or by drilling a coagulation bath outlet hole in the flow tube near the flow tube outlet.

The flow velocity of the coagulating bath near the outlet of the flow tube decreases rapidly, and a sudden bath resistance is applied to the yarn, which is still in a semi-coagulated state.

Furthermore, the bath resistance vector near the flow tube 9 is distributed in a complicated manner in various directions other than the running direction of the yarn.

Moreover, since the direction changes every moment, the yarn, which is still in a semi-solidified state, is agitated in a complicated manner. Therefore, the semi-coagulated surface of the single yarn, which is still weak, will suffer minute damage due to rapid changes in bath resistance, or the single yarn will cause stretching irregularities due to complicated oscillations, resulting in yarn breakage during the spinning process. Process defects such as fuzz occur, and furthermore, the physical properties of the product yarn after the post-processing process are reduced, especially the elastic physical properties such as dry elongation, wet elongation, Young's modulus, and shrinkage rate, and unevenness occurs.

For example, in the method described in Japanese Patent Publication No. 30-8866, the coagulation bath exiting the flow tube is once blown up into the air and then enters the overflow receiving tank, thereby avoiding a sudden decrease in the flow rate of the coagulation bath. However, since the coagulation bath is blown up vertically after the outlet of the flow tube, the height and direction of the top of the blown up coagulation bath fluctuate with time, and the yarn, which is still in a semi-solidified state, is not solidified. When the yarn passes through the apex of the spouting coagulation bath, it is affected by the complex oscillations that cause stretching unevenness, which results in unevenness in the physical properties of the product yarn, especially in its stretch properties. In this method, in order to suppress temporal fluctuations in the height and direction of the top of the coagulating bath that is blown up, it is sufficient to reduce the length of the blown up coagulation bath. That is, the bath resistance increases and it becomes impossible to obtain a satisfactory physical property value f:. .

As a result of intensive research to solve the above drawbacks that could not be overcome with conventional methods, the present inventors discovered that the direction of flow is extremely important when causing the coagulation bath to flow upward, and thus arrived at the present invention. This is what I did.

That is, the present invention provides an upward flow tube characterized in that a flow tube is provided at an angle of inclination with respect to a line perpendicular to the ground surface, and the coagulation bath after exiting the flow tube is intentionally blown up into the air. This is a flowing bath spinning method.

According to the method of the present invention, it is possible to maintain the physical properties of raw yarn at a good level, extremely reduce unevenness in physical properties, and greatly reduce process defects such as yarn breakage and fuzz. Useful in high speed spinning.

An example of an embodiment of the present invention is shown in FIG. The present invention is the first
This will be explained in detail using figures. The spinning dope passes through the spinning dope introduction tube 4, passes through the spinneret 6 installed on the spinneret support 5, and is discharged into the coagulation bath introduced through the coagulation bath introduction tube 2, into the semi-coagulated yarn 7. While forming a coagulation bath, it passes through the inside of the flow tube 8 together with the coagulation bath, and is completely solidified while passing through the blown-up coagulation bath 9 which is intentionally blown up into the air from the outlet of the flow tube 8. The fibers reach the top of the blown coagulation bath 9 and are taken out to form coagulated threads 10 for post-treatment if necessary.

In the present invention, the reason why the blown-up coagulation bath 9 is intentionally blown up into the air is as follows.

That is, if the angle between the vertical angle ln with respect to the ground surface and the WI line 12 of the flow tube is θ, then the coagulation bath passing through the inside of the flow tube 8 at a flow rate V in the direction of yarn movement is Flow velocity at the outlet■
As is well known in elementary mechanics, when the gravitational acceleration is 1, it is blown up to a length H of H = V'' / (2? cos θ), and at the top of the blown-up coagulation bath, the flow velocity becomes 0 and it stops falling. Start. Therefore.

The yarn, which has not yet completely coagulated at the time of passing through the outlet of the flow tube 8, is blown up to reach the top of the coagulation bath 9 in order to complete coagulation. We only experience a very slow decrease in velocity proportional to the W power of the distance, that is, a very slow increase in bath resistance (force).Furthermore, the rate of velocity decrease of the blown-up coagulating bath increases.1. In other words, in areas where the degree of coagulation of the yarn is relatively low, the increase in external force is small, and as the coagulation of the yarn becomes sufficient, the increase in external force increases. In a sufficient area, the external force applied to the surface is small, so damage to the semi-coagulated surface and stretching spots are unlikely to occur, while in areas where a large external force is applied, coagulation of the yarn has progressed sufficiently. It is said that large surface damage and stretching spots no longer occur.

It goes through a very rational process. Furthermore, as the spinning speed increases, it becomes necessary to increase the flow rate in the flow tube in order to maintain a good level of physical properties, so it is clear that it is more advantageous and necessary for the yarn to undergo the above steps. .

Intentional spouting of coagulation bath into the air as referred to in the present invention means:
This is the basic principle for producing the above phenomenon. For example, by providing an overflow receiving tank, a funnel pipe whose cross-sectional area increases as it progresses, or a perforated flow pipe that has a cross-sectional area larger than the flow pipe, the coagulation bath flowing out from the flow pipe can be collected as an overflow. This is a method of flowing out the coagulation bath that does not cause the coagulation bath to decrease rapidly due to overflow. Refers to a type having a blown-up coagulation bath of a finite length in the direction in which the strip travels. The intended length of the blow-up bath should be determined by the spinning speed, the desired level of physical properties, or the setpoint of the flow rate of the coagulation bath in the flow tube. In addition, in order to intentionally spray the coagulation bath into the air from the outlet of the flow tube, it is necessary to pressurize the coagulation bath in some way. It is preferable to eject it by.

However, even by simply providing the above-mentioned intentional jetting of the coagulation bath, it is still difficult to bring the unevenness of physical properties to a level that does not pose any problem when using the product yarn. Even in the previously proposed upflow bath spinning method,
Although there is a concept of causing the coagulation bath to flow upward, it is nearly impossible to obtain a product yarn that is sufficiently homogeneous for practical purposes using this technique alone. This is because when the blown-up coagulation bath is blown up perpendicular to the ground surface, variations in gravity acting on the blown-up coagulation bath, bath speed, yarn running, etc. affect each other in a complex manner, resulting in the blown-up coagulation. The height and direction of the apex of the bath, that is, the apex position, changes moment by moment with time. A familiar example of this phenomenon is the vertical spouting of water from fountains in parks and the like. Therefore, in the upflow bath spinning method using the blow-up method, the flow tube has an inclination angle with respect to the vertical #11 with respect to the ground surface in order to suppress the fluctuation in the position of the top of the blow-up coagulation bath and to extremely reduce stretching unevenness. It is necessary that the According to the results of detailed research by the inventors, it is preferable that the inclination angle θ is in the range of 5 to 20 degrees. If θ is too small, the apex position of the spouting coagulation bath 9 will not be fixed as described above, and the tension applied to the yarn will vary greatly in both magnitude and direction, which will affect the physical properties of the product yarn, especially Unevenness in elastic properties such as dry elongation, wet elongation, Young's modulus, and shrinkage rate tends to occur along the yarn length direction, and on the other hand, if the line angle θ is too thick, the equipment space per weight increases. As a result, the productivity of the equipment decreases, and the necessary shelving area becomes large, making spinning operations more frequent and making production on an industrial scale a little more difficult. Furthermore, the width of the apex of the spouted solid bath expanded and began to fluctuate constantly, and furthermore, external force due to the fall of the at solid bath began to be applied to the yarn running in the spouted coagulation bath, causing the yarn to become smooth. They are guaranteed to run and become chicks.

Therefore, in order to suppress fluctuations in the position of the apex of the coagulation bath, extremely reduce stretching unevenness, and facilitate manufacturing on an industrial scale, it is necessary to provide flow tubes with an inclined angle. More preferably, the inclination angle θ is in the range of 5 to 20 degrees.

As described above, the present invention provides a flow tube having an angle of inclination with respect to the perpendicular to the ground surface, and the coagulation bath after exiting the flow tube is
The top-flow bath spinning method, which is characterized by intentional spraying into the air, maintains the properties and properties of the raw yarn at a good level, extremely reduces unevenness of properties, and further improves the quality of the yarn. Since there are no scratches or drawing irregularities on the surface of the yarn, the product yarn, which has greatly reduced process defects such as yarn breakage and fuzz, is stable and easy to use on an industrial scale, especially during high-speed spinning. can be manufactured.

The present invention will be explained below with reference to examples, but the present invention is not limited to the following examples.

Example: Cellulose concentration 8.0% by weight, produced by a conventional method.
viscose with an alkali concentration of 5.5% by weight was produced by a conventional method) i2sO4150? /L, Na2SO
A 120 denier yarn was spun at a spinning speed of 200 m/min by the spinning method shown in FIG. 1 in a coagulation bath of 4280 f/l 5ZnSO4 and 15 t/l at 52°C. The spinneret was 0.06*mφ×26 holes (made of platinum), and the flow tube was a glass tube with an inner diameter of 511° and a length of 100 m. The coagulated yarn passed through a thread path and rollers, was wound up into a centrifugal pot, and was subjected to conventional post-treatment to form a product filament.

The inclination angle θ of the flow tube is 0 to 25 degrees, and the length of the jet coagulation bath is L.
The number of occurrences of yarn breakage (times/weight 0 days) and the number of fuzz occurrences (pieces/10'm) measured by the two-part fuzz detection method when changing the thread length from 100 to 500 times were determined as Shown in Figure 2. Furthermore, as a representative physical property value, continuous strength and elongation measuring skin manufactured by Worcester Co., Ltd. (Ty
pe 96 ), the dry elongation of the yarn was continuously measured every 1 m over 100 m.

Table 3 shows the average value i and standard deviation value σ of the dry elongation of the yarn when the inclination angle θ of the flow tube and the top length H of the coagulation bath were varied.

Table 1 (extra colors above) Table 2 Table 3 Comparative Example 1 A cylindrical overflow receiving tank with an inner diameter of 50 mm was installed continuously at the outlet of the flow tube 8 shown in Figure 1, and 20 m+ from the flow tube outlet. H = 100 in Example 1 when the inclination angle θ of the flow tube was set to 0 and 12 degrees, except that the coagulation bath overflowed at the height of *. 5 equivalent to 300° 500 藺
Spinning and evaluation were performed at the flow rate in the tube portion of the φ flow tube.

For ease of comparison, the flow rate is expressed as the equivalent H length in the following clothes. The number of yarn breakage occurrences (times/weight 0 days) and the number of fuzz occurrences (pieces 710'm) are shown in Tables 4 and 5, respectively, and the average and standard deviation values of dry elongation are shown in Table 6.

Table 4 Table 5 Clothing No. 6 From the above Example 1 and Comparative Example 1, the upward mud spinning method of the present invention has extremely fewer process defects than the conventional method, and is sufficiently effective for practical use. It is clear that this provides a homogeneous and extremely superior product yarn.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an example of the implementation of the present invention. 1 is the coagulation bath introduction direction, 2 is the coagulation bath introduction tube, 3 is the spinning dope introduction direction, 4 is the spinning dope introduction tube, 5 is the spinneret support, 6 is the spinneret, 7 is the semi-coagulated yarn, 8 9 indicates a flow tube, 9 indicates a coagulation bath, 10 indicates a coagulation thread, 11 indicates a line perpendicular to the ground surface, and 12 indicates an inclination line of the flow tube. Patent applicant: Asahi Kasei Industries, Ltd.

Claims (2)

[Claims] (1) Upward flow characterized by a flow tube being provided at an angle of inclination with respect to the perpendicular to the earth's surface, and the coagulation bath after exiting the flow tube being intentionally blown up into the air. Bath spinning method (2) The one-countercurrent bath spinning method according to claim 1, characterized in that the inclination angle of the flow tube is 5 to 20 degrees.