JPH042803A - spinneret - Google Patents

Abstract

PURPOSE:To obtain a spinneret producible without generating cracks in a nozzle piece and having excellent sealability, abrasion resistance, etc., of the bonded part by attaching a ceramic nozzle piece, etc., by a specific attaching method to the main body of a spinneret having a thermal expansion coefficient smaller than that of the nozzle piece. CONSTITUTION:A nozzle piece 1 made of ceramics, thermet or cemented carbide is attached to the main body 2 of a spinneret made of a metal (e.g. covar) having a thermal expansion coefficient equal to or smaller than that of the nozzle piece 1 by shrink fitting and soldering. Concretely, a fitting hole 2a is bored on the main body 2 of spinneret. The part of the hole corresponding to the shrink fitting part 3 is made to be smaller than the diameter of the nozzle piece 1 and the part corresponding to the soldering part 4 is made to be larger than the diameter of the nozzle piece 1. A nozzle piece 1 plated with metal at the soldering part is pressed into the fitting hole 2a, a soldering material 5 is placed in a gap of soldering margin and the whole assembly is heated and cooled to obtain the objective spinneret.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a spinneret used for spinning synthetic fibers.

[Conventional technology]

As shown in FIG. 3, the spinneret used for spinning synthetic fibers consists of a disc-shaped spinneret body 10 with a large number of introduction holes 11 and a spinning hole 12 communicating with the introduction holes 11.
For example, in the case of melt spinning, a synthetic fiber having a predetermined shape and thickness is obtained by spinning a molten stock solution through a spinning hole 12.

As the material of the mouthpiece body 10, metal materials such as stainless steel, ceramics, cermet, cemented carbide, etc. have been used.

In addition, there was also a structure in which a nozzle piece made of ceramics, cermet, cemented carbide, etc. was used only in the vicinity of the introduction hole 11 and the spinning hole 12, and this nozzle piece was attached to the metal mouthpiece body 10 (Japanese Patent Laid-Open No. 58 -76512).

[Issues with conventional technology]

Spinnerets made of metal materials such as stainless steel have problems in that carbides from the molten stock solution tend to adhere to them, requiring cleaning work in a short period of time, and their lifespan is short due to low wear resistance.

In addition, it is difficult to form a large number of spinning holes 12 with precision in a spinneret made of a hard material such as ceramics, cermet, or cemented carbide, and the manufacturing yield is very low. The cost was also high.

Therefore, the best structure is to attach a nozzle piece made of ceramics, cermet, cemented carbide, etc. to a metal mouthpiece body, but in this case, it is difficult to connect the nozzle piece and the mouthpiece body. For example, if you simply join using methods such as boundary fitting, press-fitting, or mechanical joining, the joining part will not be completely sealed and the molten stock will leak, and if you braze, the cap body will thermally expand. Due to the large ratio, brazing has the problem that large stress is applied to the nozzle piece side during subsequent cooling, resulting in cracks.

[Means to solve the problem]

In view of the above, the present invention uses ceramics, cermet, or cemented carbide as the nozzle piece, uses a metal having a coefficient of thermal expansion similar to or smaller than the coefficient of thermal expansion of the nozzle piece as the mouthpiece body, and uses these nozzle pieces. The main body of the cap and the base are joined together using a combination of brazing and bonding.

In addition, in this invention, the thermal expansion coefficient represents the average thermal expansion coefficient between 30-400 degreeC.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

The spinneret shown in FIG. 1 includes a nozzle piece 1 having an introduction hole 1a and a spinning hole 1b, and a mounting hole 2 formed in a spinneret body 2.
It is arranged and combined within a. This bond structure is
The step part 1c prevents the nozzle piece 1 from coming off, and the tip side of the nozzle piece l is joined by a boundary part 3 as a boundary part 3, and the rear end part is a part 4 with solder, and a brazing material 5 is inserted into the minute gap. are filled and joined by brazing.

Further, as shown in FIG. 2, another embodiment is possible, in which the step part 1c is eliminated, the nozzle piece 1 is made into a straight shape, and the bordering part 3 and the brazing part 4 are connected only by the brazing part 4.

Although only one nozzle piece 1 is shown in FIGS. 1 and 2, a large number of nozzle pieces 1 are shown in the mouthpiece body 2.
are similarly combined.

As shown in Table 1, the material of the nozzle piece 1 is ceramics such as alumina, zirconia, silicon carbide, silicon nitride, cermet, cemented carbide, or the like. The above-mentioned cermet refers to carbides, nitrides, or carbonitrides (TtC, Tt
N, TtCN, Nbc, TaC, etc.) is 50% by weight
This is a heat-resistant sintered body having conductivity and made of iron group metals (Fe, Ni, Co).

Further, as the mouthpiece body 2, a metal having a coefficient of thermal expansion comparable to or lower than the coefficient of thermal expansion of the nozzle piece 1 is used.

For example, as shown in Table 1, Kovar, 42Ni alloy, Incoloy, Invar, etc. may be used.

By making the coefficient of thermal expansion of the mouthpiece body 2 slightly lower than that of the nozzle piece 1 in this way, no stress is applied to the nozzle piece l during the brazing process during the manufacturing process, which prevents cracks from occurring during subsequent cooling. There isn't.

Table 1 [Margins below] In addition, as the connection structure between the nozzle piece 1 and the mouthpiece body 2,
Since the boundary fitting and brazing are used together, the boundary fitting part 3 can accurately position the nozzle piece 1 in the plane direction, and the brazing part 4 can completely seal the joint part.

Furthermore, in the embodiments shown in FIGS. 1 and 2, the nozzle piece 1
Although the front end side is the boundary part 3 and the rear end side is the brazed part 4, it may be conversely that the front end side is brazed and the rear end side is the boundary part 4. However, in order to accurately position the spinning hole 1b at the tip of the nozzle piece 1 in the plane direction, it is desirable that the tip side of the nozzle piece 1 be bordered.

In addition, the ratio of the length of the boundary part 3 and the length of the brazing part 4 varies depending on the material, size, or usage conditions of the nozzle piece 1, but since the brazing part 4 performs sealing, Since it is a type of joint, there is no need to make it particularly long, and it is better to make the length of the brazed part 4 less than half of the entire joint part.

Next, a method of connecting the nozzle piece 1 and the mouthpiece body 2 will be specifically explained.

Nozzle piece L: diameter 6+nn+, length 20m
m, the height of the stepped portion 1c was 3 mm, and a cermet whose main components were TiC and TiN was used, and the base body 2 was made of 42N1 alloy. First, the mounting hole 2a is drilled in the mouthpiece body 2, but at this time, the part corresponding to the boundary part 3 is smaller than the diameter of the nozzle piece 1 (the boundary width is 0.005 mm).
L.

On the other hand, the portion corresponding to the brazed portion 4 is formed larger than the diameter of the nozzle piece 1 (the diameter of the brazed portion is 0.05 mm).

Then, the brazing part of the nozzle piece l is metal plated or metallized, and is press-fitted into this mounting hole 2a, and a brazing material 5 such as silver solder is placed in the gap created by the brazing part. If the assembly is heated to about 850° C. and then cooled, the front end of the nozzle piece 1 will be bounded, and the rear end will be brazed.

The above joining method is the same even if the materials of the nozzle piece I and the mouthpiece body 2 are changed, but the border allowance, the size of the gap for brazing, the type of brazing material, the temperature for brazing, etc. will depend on each material. It is best to choose the optimal one.

Further, in the above-mentioned joining method, the boundary forming and brazing are performed simultaneously in one process, but the boundary forming process may be performed first, and then the brazing process may be performed.

Next, a spinneret having the structure shown in FIG. 1 and having 34 nozzle pieces was fabricated as a prototype, and a usage test was conducted.

As shown in Table 2, a total of 28 spinnerets were prepared in which the nozzle piece 1 and the spinneret body 2 were made of seven different materials and bonding structures, with four pieces each.

For each, the number of nozzle pieces in which cracks occurred during manufacturing and the maximum eccentricity between the center of the nozzle piece 1 and the center of the attachment hole 2a after joining were determined. In addition, for floors 1 to 7, four spinnerets were installed in one spin box, and the polymer was melt-spun at various pressures. Pressure resistant.

The results are shown in Table 2. N17 is the base body 2
Stainless steel (coefficient of thermal expansion 11~17X10-'/'
C), and due to the large difference in thermal expansion, a crank occurred in the nozzle piece 1 during manufacture, making it impossible to conduct a usage test. In addition, since the pigeon 6 was joined only by brazing, the maximum eccentricity between the nozzle piece 1 and the mounting hole 2a was as large as 0.04 to 0.05 mm, making the brazing uneven, and the withstand pressure during spinning was 100 kg 7 cm2. It was low. Furthermore, since 11h5 was bonded only through the border, the sealing properties of the bonded portion were poor, and the withstand pressure during spinning was 1.
The pressure resistance was as low as 50 Kg/cm2. Generally, the above-mentioned pressure resistance is required to be 250 Kg/cm2 or more, but none of the test cases 5 to 7 met this requirement.

In contrast, in each of the first to fourth embodiments of the present invention, the cap body 2
Since a metal with a coefficient of thermal expansion comparable to or smaller than that of the nozzle piece 1 is used, and boundary fitting and brazing are used together, there is no cranking of the nozzle piece, and the maximum distance between the nozzle piece 1 and the mounting hole 2a is Eccentricity is 0.01~0
．． Since it was small at 0.2 mm, it also had excellent sealing properties, and showed excellent results with a pressure resistance of 300 Kg/cm2 or more.

[Margin below]

[Effects of the Invention] As described above, according to the present invention, a nozzle piece made of ceramics, cermet, or cemented carbide is attached to a mouthpiece body made of a metal whose coefficient of thermal expansion is similar to or smaller than that of the nozzle piece. By attaching the spinnerets using a combination of bonding and brazing, cracks do not occur in the nozzle pieces during manufacturing, and a spinneret with excellent nozzle positioning and joint sealing properties can be obtained. Also,
Since the spinning hole is made of ceramics, cermet, or cemented carbide, there is less adhesion of carbide from the molten stock solution and less wear, resulting in a long life. Furthermore, the nozzle piece is attached to the structure.
It is possible to provide a spinneret with many features such as high yield during production and low cost.

[Brief explanation of drawings]

1 and 2 are partial cross-sectional views of spinning nozzles according to embodiments of the present invention, respectively. FIG. 3 is a partially cutaway side view showing a conventional spinning nozzle. l: Nozzle piece 1b: Spinning hole 3: Boundary part 5: Brazing part 1a: Introduction hole 2: Mouthpiece body 4: Brazing part

Claims (1)

[Claims] Attaching a nozzle piece made of ceramics, cermet, or cemented carbide to a mouthpiece body made of a metal whose coefficient of thermal expansion is similar to or smaller than that of the nozzle piece using a combination of shrink fitting and brazing. A spinneret featuring: