JPS58115112A - Melt spinning method - Google Patents

Abstract

PURPOSE:To prevent the generation of carbonized materials and sticking of monomers to the surface of a spinneret and obtain hollow fibers at a low cost, by allowing a heated inert gas to be present between a spinneret and a steam layer in melt spinning a synthetic polymer. CONSTITUTION:An inert gas which is a gas at ordinary temperature and heated at a higher temperature than steam is blown from an inert gas supply conduit 6 through an inert gas blowing slit 4 provided 10-50mm. below the surface of a spinneret 1 on extruded filaments while uniformly rectified by a punched plate 7, and steam superheated to 110-150 deg.C from a steam supply conduit 8 through a steam jetting wire net pipe 5 provided below the blowing slit 4 to seal a spinneret 1 and melt spin a synthetic polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing the formation of carbides on the spinneret surface, and more specifically, the present invention relates to a method for preventing the generation of carbides on the spinneret surface, and more specifically, the present invention relates to a method for preventing the generation of carbides on the spinneret surface. This is a method for preventing the formation of vertical particles and the adhesion of nanano-1- to the gold surface of hollow fibers IIhfGp by sealing with an inert gas heated to a higher temperature.

Generally, when a polymer containing several or more seven-mers (e.g., Nai ρ) is made into static-melting fat fiber during polymerization, the polymers are vaporized into the atmosphere as a result of the ballimer spun from the spinneret surface. When the steam comes into contact with the hot spindle surface, it becomes carbide and accumulates, and when the carcasses that form around the spindle hole grow to a certain size, they come into contact with the spun yarn and become a layer, causing abnormalities. It becomes a thread of the shape and causes KIE team in terms of the type of work and quality.

In the past, various methods have been tried to prevent the formation of vertical grains around the raw gold mine, but among these methods, the method of sealing the mouth surface with an inert gas such as water vapor or nitrogen ( r# Kosho 38-12365! and special public Sho 44-z
xxa9@) is effective in achieving the intended purpose,
In particular, a method using water vapor as an inert gas is often used.

However, the method of blowing steam has the following five drawbacks.

In other words, in recent years, hollow fibers have been increasingly used for purposes such as increasing the bulkiness of * and m or changing the gloss after dyeing. When sealing with water vapor, there is a problem in that the water vapor that has penetrated into the inside of the fiber shrinks as the yarn cools and assimilates, making it impossible to ensure the hollowness ratio at all. Its use is a definite drawback.

On the other hand, in order to ensure a 9-9 ratio, a method of blowing nitrogen instead of steam is often used, but even in this case, a number of drawbacks arise.

In other words, if a large amount of nitrogen is used with many spinning spindles, the room will be filled with nitrogen vapor leaking from the individual spindles and spindles, creating an oxygen-deficient state and causing the surrounding working fabric to become medium bulky or worse. In this case, a very serious problem arises in terms of safety management, such as fatal accidents. For this reason, various safety equipment such as an automatic oxygen concentration measurement alarm device and an automatic nitrogen blow-out control iron stand are installed in various parts of the room when nitrogen is used, but these are not perfect. The amount of capital investment will be extremely high. In addition to IJO, the price of nitrogen itself is high, so if a large amount of nitrogen is constantly sprayed, the running cost will be very high.

The inventor of the present invention has made extensive studies to eliminate the conventional interlacing point, and as a result, has discovered that it is sufficient to interpose an inert gas between the spinning point and the steam layer. Original IUK
Reached.

That is, the present invention provides Kl! which seals the lower part of the spinneret with water vapor in #melt spinning of synthetic polymers. This bath-melt spinning method is characterized in that an inert gas which is a gas at room temperature and heated to a temperature lower than the steam temperature is interposed between the spinneret surface and the steam layer.

The synthetic polymers used in the method of the present invention include synthetic polymers that can be melt-spun, such as polyesters and polyamides, but the effect is remarkable in the case of polyamides.

The figure clarifies one embodiment of the present invention, and the yarn 2 spun from the spinneret 1 is taken out after being cooled and solidified by cooling air or the like in the spinning tube 3.
An inert gas blowing slit 4 and a water vapor blowing wire mesh pipe 5 are provided in this order from above between the spinning tube 3 and the spinning tube 3.

From the inert gas blowing slit 4, an inert gas that is a gas at room temperature and heated to a temperature lower than the water vapor temperature is blown onto the surface of the spinneret 1, and the spinneret surface is blown. The inert gas supply conduit 6 is a punching plate for uniformly rectifying the inert gas. The inert gas blowing slit 4 is designed to blow out the inert gas vertically and in a rectified manner to the yarn 2 spun from the spinneret 1, and the blowing slit 40 has a width of 2 to 30 mm. The installation position is preferably 10 to 50 cm below the reduced area of the spinneret 1 and as close to the spun yarn 2 as possible.

On the other hand, the steam is superheated to 110-150°C and passes from the steam supply conduit 8 to the steam blowing wire mesh pipe 5 to the spinneret 1.
is fed under the spinneret 1 and seals the spinneret 1. here,
The inert gas blown out from the inert gas blowing slit 4 must be a gas at room temperature and must be heated to a higher temperature than water vapor. By making the temperature of the inert gas higher than the water vapor temperature, the inert gas has a lower density than the water vapor and stays on the spinneret surface, preventing the water vapor from coming into contact with the spinneret surface, thereby eliminating the drawbacks of water vapor seals. However, if the temperature of the inert gas is lower than the water vapor temperature, the effects of the present invention cannot be achieved. Also, the inert gas is typically used at a temperature below the temperature of the molten polymer. Inviscid gas flow cap is 10-3
ON@/time is preferred.

In the present invention, it is not necessary to completely block water vapor from the spinneret with an inert gas, and within the range that does not impair the effects of the present invention, water vapor can be used in the inert gas that covers the spinneret surface. I don't mind if you do that.

In addition, examples of the inert gas that is gaseous at room temperature used in the present invention include nitrogen, helium, and carbon dioxide.

As described above, according to the present invention, since the spinneret surface is always sealed with inert gas and water vapor, it is possible to prevent the generation of carbides and the adhesion of 7-mer on the spinneret surface, and furthermore, Since the inert gas is interposed between the face and the water vapor layer, water vapor does not come into direct contact with the spinneret face and enter the hollow part of the spun yarn, reducing the hollowness ratio. By using this together, the leakage of bond gas into the room is sealed with water vapor, which eliminates the safety issues such as indoor oxygen deficiency caused by continuous blowing of only inert gas such as nitrogen, and reduces capital investment. The amount and running costs can also be significantly reduced.

The present invention will be explained in more detail with reference to Examples below.

Examples 1-4. Comparative Examples 1 to 2 When spinning a nylon 6 hollow fiber having an equilateral triangular cross-sectional shape and three hollow parts therein using a spinneret with 6s nozzles at a spinning temperature of 250°C, Spinning was carried out using the apparatus shown in Figure 2, while sealing the spinneret surface.

That is, an inert gas blowing slit 4 having a width of 5 inches was provided 30 inches below the spinneret surface, and nitrogen gas was blown out from the slit 4 in a direction perpendicular to the spun yarn 2. Furthermore, steam superheated to 130° C. is blown out at a rate of 4j1o oz/min from a steam blowing wire mesh pipe 5 provided below the slit 4, and cooling air is blown out from the spinning tube 6 provided below to create a smooth discharge stream. After solidification, it was drawn at a take-up speed of 500@/xm, and then stretched 3.4 times to obtain a drawn yarn of IAOO denier. At that time, the degree of contamination of the spinneret teeth and the cross-sectional shape of the spun yarn were observed by varying the amount of scum and the nitrogen gas temperature, and the results are shown in the following table.

*Spinneret fouling time is the time taken until carbide or monomer adheres to the spinneret surface and yarn breakage occurs during the spinning process, or yarn breakage occurs when the spun yarn is stretched. means (day).

As is clear from the table, in Comparative Example 1, in which the spinneret surface was directly sealed with water vapor, the yarn hollowness was low and the hollow portion was deformed greatly, but nitrogen gas was interposed between the spinneret surface and the water vapor layer. In Example 1-S4, the yarn hollowness was large and the deformation of the hollow portion was small. In addition, the nitrogen gas temperature is lower than the water vapor layer (1
In Comparative Example 2, where the temperature was lower than 30° C.), there was no water vapor blocking effect, the yarn hollowness was low, and the hollow portion was greatly deformed.

[Brief explanation of the drawing]

The figure is a schematic diagram for explaining an embodiment of the present invention. 1... Spinneret 2... Spun yarn 4... Inert gas blowout 5... Steam blowout wire mesh pipe slit Patent applicant Teijin Ltd.

Claims (1)

[Claims] L In am spinning of synthetic polymers, when sealing the lower part of the spinneret with water vapor, an inert gas that is a gas at room temperature and heated to a temperature higher than the water vapor temperature is placed between the spinneret surface and the water vapor layer. To intervene! Melt spinning method that uses mold.