JPH04281004A - Spinning nozzle improved in pressure resistance - Google Patents

Abstract

PURPOSE:To obtain the title spinning nozzle internally fitting a reinforcing member on the inside of peripheral part of a spinning nozzle having vertical peripheral edge part to spinning hole opening face, improved in pressure resistance and prevented in fall to the inside of the peripheral edge part by discharge pressure and swelling of the spinning hole opening face. CONSTITUTION:An article having 140mmphi of a spinning hole opening face 1, 382mm of spherical surface radius to dope discharge direction of the face of the peripheral edge part 2, 12.7mm of height of the peripheral edge part 2 and a flange part 3 extending from the peripheral edge part 2, and having 160mmphi outside diameter and being 19mm in height from circular plane made of the flange part to the central top of spinning hole opening face is formed from a flat plate made of tantalum by press molding. Then, 40000 spinning holes having 0.030mmphi hole diameter are bored by punching method by using a punch to provide spinning nozzle body and a reinforcing member 4 made of the same material as the body, having shape along the peripheral part 2 and flange part 3 with 3mm thickness is prepared by lathe work. The reinforcing member 4 is fitted to the inside of the peripheral part 2 of the spinning nozzle to provide the objective spinning nozzle improved in pressure resistance.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spinneret with improved pressure resistance useful in fiber spinning.

0002

[Prior art] Manufacturing of fibers. ．． ．． ．． Particularly in spinning, spinnerets play an extremely important function, and spinnerets with spinning holes formed in metal or other materials are often used. Recently, many functions are required of such spinnerets. That is, it is possible to spin fine denier yarn, it is possible to obtain a high spinning speed, and it is possible to increase the productivity per spinneret by increasing the number of spinning holes.
etc.

[0003] In order to meet such requirements, for example, the diameter of the spinning hole is reduced for fine denier spinning, or the cross-sectional area of the opening is reduced for yarn with an irregular cross section. To obtain a high spinning speed, the thickness of the spinneret plate must be increased to withstand high-speed discharge of the spinning dope (solution or melt), and to increase the number of spinning holes per spinneret, the thickness of the spinneret plate must be decreased. , etc. are being carried out.

However, the diameter of the spinning holes (or the cross-sectional area of the openings)
Reducing the spinning dope will inevitably result in an increase in the discharge pressure as well as high-speed discharge of the spinning dope, which will cause the spinneret plate to curve, swell, and even break, so in order to prevent this, the thickness of the spinneret plate must be increased. You won't get any more. An increase in the thickness of the spinneret plate results in a decrease in the number of spinning holes that can be formed due to constraints on spinneret processing. On the other hand, reducing the thickness of the spinneret plate in order to increase the number of spinning holes can avoid the problem of drilling the spinning holes, but it results in a decrease in pressure resistance against the discharge pressure of the spinning dope. Similarly, increasing the number of spinning holes by increasing the area of the spinneret also causes a decrease in pressure resistance.

As mentioned above, there are conflicting factors involved in making the spinning holes of the spinneret smaller in diameter (or smaller in area), increasing the number of spinning holes, and making them durable for high-speed discharge. Although efforts have been made to improve the strength of the material itself and to harden the surface of the die after processing, the current situation is that no definitive solution has been found.

[0006]

[Problems to be Solved by the Invention] An object of the present invention is to overcome the above-mentioned current problems and to provide a spinning yarn with improved pressure resistance that can withstand narrowing of the spinning hole, increasing the number of holes, and high-speed discharge. The purpose is to provide funds.

[0007]

[Means for Solving the Problems] The present invention is characterized in that, in a spinneret having a peripheral edge substantially perpendicular to the opening surface of the spinning hole, a reinforcing member is fitted inside the peripheral edge. The spinneret has improved pressure resistance.

First, a spinneret according to the present invention having a peripheral edge substantially perpendicular to the opening surface of the spinning hole will be described. The spinning hole opening surface refers to the side of the spinneret where a large number of spinning holes are drilled, through which the spinning dope is discharged in a fixed amount and comes into contact with the coagulating liquid or solidifying medium. The surface may have a planar shape or a spherical shape convex with respect to the direction in which the spinning dope is discharged.Furthermore, the planar shape of the surface is mainly circular, but square, rectangular, and even rectangular shapes are also included.

FIG. 1 is a schematic sectional view illustrating an embodiment of the spinneret of the present invention, which has a circular planar shape and a convex spherical shape in the direction of discharge of the stock solution. This shows an example in which a different reinforcing member holding method is adopted, and numeral 1 in the figure is the above-mentioned spinning hole opening surface. Reference numeral 2 in the figure indicates a peripheral edge, and the device may have a flange indicated by 3 in the figure, which extends from the peripheral edge. The collar is also useful for attaching a spinneret to a spinning head or for fitting and retaining the reinforcing member of the present invention.

[0010] The peripheral edge 2 being substantially vertical means that it extends approximately perpendicular to the spinning hole opening surface 1, whether it is spherical as in this example or planar. However, this does not mean that the angle between 1 and 2 is strictly 90°. Furthermore, I would like to add that
It can also be said that the peripheral edge is approximately parallel to the direction in which the spinning dope is discharged.

Next, the method of fitting the reinforcing member inside the peripheral portion will be explained. In Figure 1, the inner side of the periphery is
Refers to the inside of the space created by the spinning hole opening surface 1 and the peripheral edge 2 formed in a shape that surrounds the surface, excluding the side immediately behind the spinning hole opening surface 1. . In other words, it can be said to be the side through which the spinning dope passes through the substantially vertical peripheral edge.

A reinforcing member is fitted inside the peripheral edge portion to improve the pressure resistance of the spinneret.The reinforcing member, which is an important component of the present invention, will be explained below.
The reinforcing member is provided along the inside of the substantially vertical periphery, and it is necessary that the reinforcing member is installed along the inside of the periphery with a minimum necessary gap, and more preferably, the reinforcing member is provided along the inside of the periphery. It is best to fit inside the section.

As for the shape of the reinforcing member, since it follows the inner side of the peripheral edge, it cannot be absolutely limited, but 4 in the figure in FIG. 1 shown as one example is the reinforcing member, and as shown in the figure,
That is, there is a hollow cylindrical shape with a flange. Of course, depending on the shape of the periphery, hollow square, rectangular, or rectangular shapes may also be adopted.

Although FIG. 1 shows an example of a reinforcing member with a flange,
The flange is not essential, and the present invention also includes those without a flange or those in which the flange is formed from a separate member and used as an integral part.

Furthermore, the reinforcing member is manufactured separately from the spinneret, and in some cases the reinforcing member is inserted (attached) inside the peripheral edge of the spinneret each time the spinneret is used, and in others, the reinforcing member is manufactured separately from the spinneret. are connected together. ．． ．． ．． It is shown on the right side of Figure 1. ．． ．． ．． is also suitably used.
In addition to the method shown in the figure, screws or caulking may be used to connect the parts together.

Regarding the size (dimensions) of the reinforcing member, the required pressure resistance of the spinneret, the allowable size of the reinforcing member, the material of the spinneret itself and the reinforcing member used, the spinneret described above, etc. This is controlled by factors such as its own shape, and is extremely difficult to limit. The only limitation is that the inner diameter of the hollow cylindrical portion of the reinforcing member in FIG. This means that the dimensions do not cover the holes on the back side of the spinning holes (referred to as back holes) that exist in the spinning holes.

Next, the material of the spinneret itself and the reinforcing member will be explained. These materials are not limited, and conventionally used materials or other materials can be used.
Further, the spinneret and the reinforcing member may be made of the same material or may be made of different materials, but in the latter case, dimensions should be adopted that take into account the thermal expansion of both materials. Examples of materials that can be used include Au/
Pt alloy, Pt, Ta, Ti and even stainless steel.
Examples include metals, glass, ceramics, and synthetic resins.

[0018]

EXAMPLES Examples are shown below to facilitate understanding of the present invention, but these are merely illustrative and the gist of the present invention is not limited thereto.

[0019]

【Example】

[1] FIG. 1 is a schematic sectional view illustrating one embodiment of the spinneret of the present invention. In Example 1, a spinneret featuring the left half of FIG. 1 was manufactured. That is, a tantalum flat plate (t=
0.75mm) to outer diameter of spinning hole opening surface 1 140mmφ
, has a spherical radius of 382 mm in the undiluted solution discharge direction of the surface, a flange 3 extending from the periphery with a height of 12.7 mm, and the outer diameter of the flange is 160 mmφ. Height from the circular plane to the center top of the spinning hole opening surface 1 (
A piece with a height of 19 mm (hereinafter abbreviated as the top rising height) was processed by a press molding method. Then the pore diameter is 0.030
A spinneret body was formed by punching out 40,000 mm diameter spinning holes using a punch.

[0020] The reinforcing member 4 is made of the same material as the spinneret body and is machined by lathe processing, and has the same shape as the reinforcing member 4 shown in Fig. 1 along the peripheral edge part 2 and the collar part 3, has a thickness of 3 mm, and has a thickness of 3 mm. It was made to fit into the inner diameter of No. 2 without any gaps.

Next, the reinforcing member 4 was fitted to the manufactured spinneret body to obtain the spinneret of the present invention. As a comparative example, a spinneret body manufactured by the same method but differing only in that no reinforcing member was attached was used.

Wet spinning of acrylonitrile copolymer (
0.5 d/f x 200 m/min) using a conventional method for a spindle equipped with the spinneret of the present invention and a spindle equipped with a spinneret of a comparative example for simultaneous comparison. Spinning time is 20H
It was set as r.

[0023] With the spindle of the spinneret of the present invention, good spinning was maintained from beginning to end, and no single fiber breakage was observed in the gel yarn produced from the hot water drawing process. With the spindle of the comparative example, although this was not observed at the beginning, in the latter half of spinning, the gel yarn had about 23 nep-like single filament breaks per minute, and was not a first-class product.

After spinning for 20 hours, the spinnerets were removed from the spindle and washed, and the heights of the tops of both spinnerets were compared. The spinneret of the present invention had a diameter of 19.1 mm, whereas the spinneret of a comparative example without a reinforcing member had a diameter of 22.1 mm.
It was observed that a so-called bulge had occurred.

[0025] The frequent occurrence of single yarn breakage is considered to be an adverse effect of the expansion of the variation in hole diameter between each spinning hole due to the bulge of the spinneret, which has poor pressure resistance, and the absolute value of the top rising height also indicates that the spinneret of the present invention has poor pressure resistance. It is understood that this material has excellent properties and is therefore suitable for improved spinnability and high-speed spinning.

[0026]

[Effects of the Invention] When the spinning dope is discharged through the spinneret, the discharge pressure generates a force that pushes out the opening surface of the spinning hole in the discharge direction. This force acts as a tangential pull on the opening surface of the spinning hole, and this acting force eventually has the effect of pushing the peripheral edge 2 in FIG. 1 inwardly, for example in the centripetal direction in the case of a circular spinneret.

[0027] In the spinneret of the present invention, since the reinforcing member provides resistance to the applied force, deformation of the opening surface of the spinning hole is prevented, that is, the pressure resistance is improved.

In order to improve the pressure resistance in this way, it is possible to increase the discharge rate of the stock solution to achieve a high spinning speed, or to increase the production rate by increasing the spinning speed of the stock solution with a high viscosity (in the case of wet spinning, it is possible to achieve a high polymer concentration). In other words, the number of spinning holes that can be drilled can be increased due to improved pressure resistance with the same plate thickness. The number of holes can be increased without increasing the area of the spinneret, and for the same reason, the diameter of the spinning hole can be reduced (or the cross-sectional area can be narrowed), making it easier to achieve fine denier. A noteworthy effect of the present invention is that the service life is also extended.

[0029]

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view illustrating one embodiment of the spinneret of the present invention, which has a circular planar shape and a spherical shape that is convex with respect to the raw solution discharge direction, and the left and right halves hold different reinforcing members. It shows the method.

[Explanation of symbols]

1 Spinning hole opening surface 2 Peripheral area 3 Tsubasa 4 Reinforcement member

Claims (1)

[Claims] Claim 1: A spinneret with improved pressure resistance, characterized in that the spinneret has a peripheral edge that is substantially perpendicular to the opening surface of the spinning hole, and a reinforcing member is fitted inside the peripheral edge. .