JPS6257905A - Spinneret - Google Patents

Abstract

PURPOSE:A spinneret providing yarn having stable qualities of yarn such as crosssectional shape, thickness, etc., having an extremely prolonged washing period in the circumference of spinning hole, wherein a part of a stock solution feed hole to be brought into contact with a spinning stock solution, containing the spinning hole, consists of a cermet. CONSTITUTION:A part of the stock solution feed hole 5 to be brought into contact with a spinning stock solution, containing at least the spinning hole 6, consists of the cermet 3, to give the aimed spinneret. EFFECT:The spinneret can be processed by electric discharge. Various kinds of yarn can be obtained by combining chips having different spinning hole shapes. USE:Effective for nylon 6, nylon 66, et.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to improvements in spinnerets for synthetic fibers.

BACKGROUND OF THE INVENTION Conventionally, the spinneret used for bath-melt spinning synthetic fibers is generally made of stainless steel, which has excellent corrosion resistance and good workability, and is integrated as shown in FIG. In addition, the original i4 including the base and spinning hole that makes the ceramic whole
The spinneret is made of hard glass, ceramic, or cemented carbide as the material for the hole (Japanese Patent Laid-Open No. 58-7
6512) is known.

Problems to be Solved by the Invention The above-mentioned spinnerets made of stainless steel have the problem that carbides, which are generated when unreacted substances of the raw solution come into contact with oxygen in the air, tend to adhere around the spinning nozzle of the spinneret. However, the spindle that integrates ceramics lacks toughness and is easily broken, and it is difficult to process a spinning hole with a complicated shape. Similar to stainless steel, cemented carbide has the problem that carbides tend to adhere to it.

As mentioned above, the biggest problem with spinnerets for synthetic fibers is that during operation, carbide adheres and accumulates around the spinning hole, resulting in variations in the surface shape and thickness of the spun yarn. . Therefore, the spinneret must be cleaned at regular intervals before the yarn becomes uneven. When the spinneret is normally made of stainless steel, carbides tend to adhere to it. For example, in a spinning hole spinneret with a round shaped surface for nylon 6 and nylon 66, the frequency is once every 40 hours at the maximum to remove carbides, and in a spinneret with a complex cross-section of the spinning hole, once every 8 hours. The area around the spinning hole is cleaned every once in a while.

Naturally, it is not spun out during cleaning, and a considerable amount of labor is required, which directly affects manufacturing costs.

A well-known method for extending the cleaning cycle around the spinning hole during spinning is, for example, sealing the bottom surface of the spinneret with an inert gas to completely suppress the formation of carbides, but this method requires a large amount of investment. In addition, superheated steam, nitrogen, etc. must be used for sealing, which affects operating costs, and also has poor workability during attachment and detachment of the spinning bag and cleaning of the bottom surface of the spinneret.

In recent years, improvements have been made in the use of ceramic, hard glass, and cemented carbide as spinneret materials, but what about ceramic and hard glass? Since it is an electrically non-conductor, it is easily cracked due to its low toughness. Also, because it is electrically non-conducting, it is used for electrical discharge machining, that is, the tool and side workpiece are each used as electrodes in an insulating liquid, and sparks are discharged between them. Since it is not possible to remove minute amounts of surface gold, there is a natural limit to the cross-sectional shape of the spinning hole, and it is not possible to process a spinning hole with a complicated cross-sectional shape.

Furthermore, like stainless steel, cemented carbide has the problem that carbides tend to adhere around the spinning holes.

Means for Solving the Problems In order to solve all of these problems, the inventors of the present invention have worked diligently to discover the most suitable cermet as the material for the spinneret.
This led to the present invention.

That is, the present invention is a spinneret in which the surface of the spinning dope is made of cermet. The spinneret body preferably has a structure in which cermet is held between an upper plate and a lower plate.

In the spinneret of the present invention, cermet is used as the material of at least the dope introduction hole which serves as the upper part of the spinning hole on the surface that comes into contact with the spinning dope. Cermet is a heat-resistant sintered body made of metal and metal compound gold, and is made by sintering metal powder with carbides, injections, borides, nitrides, oxides, etc., which have a melting point around 6000°C. It is a body. In addition, cermet has a high melting point,
It is ultra-hard and has excellent properties such as acid resistance at high temperatures, corrosion resistance, and mechanical strength, so it is suitable as a material for spinnerets because it has ceramic-like characteristics such as good dope moldability and good hole machinability. It has metal-like characteristics.

The present invention will be explained below with reference to FIG.

Figure 1 shows the structure of an example of the spinneret of the present invention. The upper plate 1 and the lower plate 2 are divided in the direction perpendicular to the entire axis of the spinneret body, and a cermet 3 is provided on the surface in contact with the spinning dope.
Insert 6 and tighten the cermet with tightening bolt 4.

Cermet on the contact surface of the spinning dope? By using this material, the releasability between the spinneret and the concentrate during spinning is far superior to that of stainless steel, which is a general-purpose material for conventional spinnerets.
When unreacted molecules of the spinning dope are spun out, they are blown away by the acid in the air and carbonized, and although a small amount of them adheres around the spinning hole of the spinneret, the adhesion between the normal dope and the adhering carbonized material does not increase. However, the adhesion is stronger than the adhesive force between the carbide and the surrounding surface of the spinneret spinning hole, and the carbide separates before it grows too much.

In addition, by making the cermet into a chip and making it easy to attach and detach, even if one hole becomes defective in a spinneret with multiple holes, the original condition can be restored by simply replacing the target cermet chip. I can recover.

Furthermore, as mentioned above, since cermet contains metal particles, it is possible to perform electrical discharge machining, making it possible to machine spinning holes of any cross-sectional shape. There is no difference.

Example 1 Using the spinneret shown in FIG.
, L//1:l-1,5 nylon round cross section thread 60c
The yarn was spun using a normal spinning method with a spinning speed of 1100"l/min and a draw ratio of 6.02. At the same time, as shown in FIG.
-1.5 spinneret was used, and spinning was carried out under the same conditions as above. Table 1 shows a comparison of the time required to clean the area around the spinning hole due to the adhesion of carbides in both cases.

Table 1 As is clear from Table 1, the cleaning cycle in the Example and Comparative Example is dramatically extended by 6.7 times.

Example 2 Using the spinneret shown in FIG. 1, nylon 66, diagonal cross-section yarn,
30 d/10 f' was spun using a normal spinning method at a spinning speed of 970 m7 minutes and a draw ratio of 2.99.

At the same time, spinning was carried out under the same conditions as above using a spinneret made entirely of stainless steel as shown in FIG.

Figure 4 shows the change in yarn cross-sectional irregularity due to the adhesion of carbides on both sides. The yarn cross-sectional irregularity is determined by measuring the lengths of A and B in the yarn cross-sectional replica shown in FIG. 6 using a microscope.

The degree of atypicality is expressed as /B. The allowable value of the degree of atypicality is 1.38.

Point E shown in Fig. 4 indicates that the underside of the spinneret needs to be cleaned twice, and while a stainless steel spinneret requires cleaning around the spinning hole once every 8 hours, a spinneret using thermets h' Now, the cycle can be extended to 40 hours.

Effects of the Invention By using the spinneret sound of the present invention, the cleaning cycle around the spinneret spinning hole can be dramatically extended, reducing product loss and labor, and improving the cross-sectional shape and thickness of the yarn. is maintained uniformly and the quality of the yarn is stable.

Also, the cermet used for the spinneret? By forming the cermet tip into a structure that is easy to attach and detach, the cermet tip itself can be replaced, which is extremely economical, and a wide variety of yarns can be produced by combining cermet tips with different spinning hole shapes.

In recent years, as the speed of yarn winding machines has increased, automation of work related to winding machines has progressed rapidly.As the spinning nozzle cleaning cycle has been lengthened, the period for intentionally cutting the spun tip has also been lengthened. All automatic equipment related to the removal machine can be operated effectively.

The present invention can be applied to synthetic fibers subjected to melt spinning, and is extremely effective for nylon 6, nylon 66, polyester, etc.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of the spinneret of the present invention. FIG. 2 is a sectional view showing the structure of a conventional spinneret. FIG. 3 is a copy of the evenly spaced IIfr face yarn in Example 1.2. FIG. 4 shows the change in yarn cross-sectional irregularity due to carbide adhesion in Example 2. 1: Spinneret upper plate 2: Spinneret lower plate 3: Cermet 4: Tightening bolt 5: Hara introduction hole 6: Spinning hole rbi shi! LLI U6 Omote Honguchi Ishi dsu T cable North = His 7th move Figure 1 Figure 2 Workplace Rokin bottom side, Sakiki A Mugi/) Spinning Drama (H ``] Procedural amendment (1 winter ) t, Indication of the case 1985 Patent Application No. 169713 2, Name of the invention Spinneret 3, Person making the amendment Relationship to the case Patent applicant name (003) Asahi Kasei Corporation name Kyocera Corporation 4, Agent Address 5-8-1o Toranomon-chome, Minato-ku, Tokyo 105,
Full text of the specification to be amended 6, Contents of the amendment The full text of the specification is amended as shown in the attached sheet 7, List of attached documents Full text of the amended specification I circular Amended specification 1, Name of the invention Spinneret 2, Scope of claims 1. A spinneret characterized in that at least a portion of the dope introduction hole that comes into contact with the spinning dope, including the spinning hole, is made of cermet. 2. The portion constituted by the cermet is formed as a separate detachable member that is held between an upper plate and a lower plate that divide the main body of the spinneret. Spinneret. 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an improvement of a spinneret for synthetic fibers. [Prior Art] Conventionally, the spinneret used for melt spinning synthetic fibers is generally made of stainless steel, which has excellent corrosion resistance and good workability, and is integrated as shown in FIG. 2. Other examples include a spinneret that integrates ceramic, and a spinneret that presses hard glass, ceramic, or cemented carbide into the spinneret plate as the material for the raw solution introduction hole including the spinning hole (Japanese Patent Laid-Open No. 58-7
6512) is known. [Problems to be Solved by the Invention] The above-mentioned spinneret made of stainless steel as one piece has the tendency for carbide, which is generated when unreacted substances of the raw solution come into contact with oxygen in the air, to adhere to the vicinity of the spinning nozzle of the spinneret. There is a problem that the die that integrates the ceramic is easy to break due to lack of toughness, and there is also a problem that it is difficult to process a spinning hole with a complicated shape. Cemented carbide, like stainless steel, has the same problem as carbide tends to adhere to it. As mentioned above, the biggest problem with synthetic fiber spinnerets is that carbides adhere and accumulate around the spinning hole during operation, resulting in variations in the cross-sectional shape and thickness of the spun yarn. Therefore, the area around the spinning hole must be cleaned at regular intervals before the yarn becomes uneven. When the spinneret is normally made of stainless steel, carbides tend to adhere to it. For example, for spinnerets with round cross-sections for nylon 6 and nylon 66, the frequency is once every 40 hours at the most to remove carbides, and for spinnerets with complex cross-sections of spinning holes, once every 8 hours. The area around the spinning hole is cleaned at a frequency of Naturally, it is not spun during cleaning, and it requires considerable labor, which directly affects manufacturing costs. A well-known method for extending the cleaning cycle around the spinning hole of a spinneret is, for example, to seal the bottom surface of the spinneret with an inert gas to suppress the formation of carbides, but this method requires a large amount of investment. Moreover, since superheated steam, nitrogen, etc. must be used for sealing, operating costs are affected, and workability during removal and removal of spinning punctures and cleaning of the bottom surface of the spinneret is also poor. In recent years, improvements have been made by using ceramics, hard glass, and cemented carbide as spinneret materials, but ceramics and hard glasses have low toughness and are easily broken, and because they are electrically nonconducting, they cannot be processed by electrical discharge machining. The tool and workpiece are each used as electrodes in an insulating liquid, and a spark discharge is caused between them.
Since it is not possible to remove small amounts of the surface of the workpiece, there is a natural limit to the cross-sectional shape of the spinning hole, and it is not possible to process a spinning hole with a complicated cross-sectional shape. Furthermore, like stainless steel, cemented carbide has the problem that carbides tend to adhere around the spinning holes. [Means for Solving the Problems] In order to solve these problems, the inventors of the present invention have conducted intensive research and found a cermet that is optimal as a material for the spinneret.
This led to the present invention. That is, the spinneret according to the present invention uses a spinning dope. It is characterized in that at least a portion of the contacting stock solution introduction holes including the spinning holes is made of cermet. It is more preferable that the portion made of the cermet is formed as a separate detachable member that is sandwiched between an upper plate and a lower plate that divide the main body of the spinneret. Cermet is a carbide of transition metals of groups 4a and 5a.
Nitride or carbonitride (Tic, TiN, T1CN
+NbC, TaC, etc.) of 50% by weight or more and iron group metals (
Fe + N r + Co ),
It is a heat-resistant sintered body with electrical conductivity. In addition, cermet has a high melting point, is ultra-hard, and has excellent properties such as acid resistance, corrosion resistance, and mechanical strength at high temperatures, so it can be used as a material for spinnerets because it has ceramic-like characteristics such as good solution releasability. It has a metal-like feature of good hole machinability. The present invention will be explained below with reference to FIG. FIG. 1 is a sectional view showing the structure of an example of the spinneret of the present invention, in which the spinneret main body is divided in the direction perpendicular to the axis, and there are an upper plate 1 and a lower plate 2, and raw material introduction holes for the spinning stock solution. It is clear that the entire structure may be made of cermet. [Function] By using cermet in at least the part that includes the spinning hole in the dope introduction hole where the spinning dope comes into contact, the releasability between the spinneret and the dope is improved compared to general-purpose materials for conventional spinnerets. Because it is far superior to stainless steel, when unreacted molecules in the spinning dope are spun out, they come in contact with oxygen in the air and carbonize, and although a small amount adheres to the area around the spinning holes in the spinneret,
The adhesive force between the falling normal stock solution and the attached carbide is stronger than the adhesive force between the carbide and the surrounding surface of the spinneret spinning hole, and the carbide separates before it grows large. In addition, by making the part made of cermet into a separate chip-like member and making it easy to attach and detach, in a spinneret with multiple holes, even if one hole becomes defective, the target cermet chip can be removed. It can be restored to its original condition by simply replacing the parts. Furthermore, as mentioned above, cermet is a heat-resistant sintered body with electrical conductivity, so it can be processed by electric discharge machining, and spinning holes of any cross-sectional shape can be formed, making it a versatile material for conventional spinnerets. It is no different from stainless steel. [Examples] The present invention will be explained in further detail with reference to Examples below. The back wheel has the structure shown in Figure 1, with a spinning hole diameter of 0.25 mmφ, -
Nylon 6 round cross-section yarn 30d/8f was spun at a speed of 1100 using four types of spinnerets according to the present invention with L/D=1.5.
The fibers were spun using a normal spinning method at a draw ratio of 3.02 m/min. 4
The compositions of cermets used in different types of spinnerets are shown in Table 1. As a comparative example, it has the structure shown in FIG. 2, and in parallel, the stainless steel shown in FIG. 2 is integrated with a spinning hole diameter of 0.
Spinning was performed under the same conditions as above using a spinneret with a diameter of 25 mm and L/D = 1.5. Table 2 shows the comparison results of the time required to clean the area around the spinning hole due to the adhesion of carbides in both cases. As is clear from Table 2, the cleaning cycle of the spinneret according to the present invention shown in the examples is approximately 7 times longer than that of the comparative examples. l Using the spinneret shown in Figure 1, nylon 66, even cross-section yarn,
30d/lof, spinning speed 970 m/min, stretching ratio 2
．． The yarn was spun using the conventional spinning method of 99. In parallel, spinning was carried out under the same conditions as above using a spinneret integrally made of stainless steel as shown in FIG. Figure 4 shows the change in yarn cross-sectional irregularity due to the adhesion of carbides on both sides. The yarn cross-sectional irregularity is determined by measuring the lengths of A and B in the yarn cross-section replica shown in FIG. 3 using a microscope. The degree of atypicality is expressed as A/B. The allowable value of the degree of atypicality is 1.38
It is. Point E shown in Figure 4 is the point at which the bottom surface of the spinneret needs to be cleaned; with a stainless steel spinneret, the area around the spinning hole needs to be cleaned once every 8 hours, whereas with a spinneret made of cermet, the area around the spinning hole needs to be cleaned once every 8 hours. The cycle could be extended up to an hour. [Effects of the Invention] By using the spinneret of the present invention, the cleaning cycle around the spinneret spinning hole can be dramatically extended, resulting in a reduction in product loss.1. Labor can be reduced, and the cross-sectional shape and thickness of the yarn are kept uniform, resulting in stable yarn quality. In addition, by making the part made of cermet into a chip in the raw material introduction hole of the spinneret and creating a structure that allows easy attachment and removal, the cermet chip itself can be replaced, which is extremely economical, and the shape of the spinning hole can be changed. A wide variety of yarns can be manufactured by combining cermet chips with different values. In recent years, as the speed of yarn winding machines has increased, automation of work related to winding machines has progressed rapidly, and as the spinneret cleaning cycle has become longer, the cycle of intentionally cutting the spun yarn has become longer. Automatic equipment related to the winding machine can be operated effectively. The present invention can be applied to synthetic fibers subjected to melt spinning, and is extremely effective for nylon 6, nylon 66, polyester, etc. 4. Brief Description of the Drawings FIG. 1 is a sectional view showing the structure of the spinneret of the present invention. FIG. 2 is a sectional view showing the structure of a conventional spinneret. FIG. 3 is a copy of the evenly cross-sectional yarn in Example 2. FIG. 4 shows changes in tea cross section and surface irregularity due to carbide adhesion in Example 2. 1... Spinneret upper plate, 2... Spinneret lower plate, 3
... Cermet tip, 4... Tightening bolt, 5... Stock solution introduction hole, 6...
...Spinning hole.

Claims (1)

[Claims] 1. A spinneret whose contact surface with the spinning dope is made of cermet.The cermet is held between an upper plate and a lower plate that divide the main body of the spinneret in the direction perpendicular to the axis, and is detachable. The spinneret according to claim 1, which is freely adjustable.