JPS6155207A - Cleaning of surface of melt spinning spinneret - Google Patents

Abstract

PURPOSE:To facilitate the cleaning operation of the surface of a spinneret for melt0spinning, by stopping the supply of polymer to a spinning pack during the melt-spinning process, and blasting a fluid toward the surface of the spinneret. CONSTITUTION:The supply of polymer to the spinning pack is stopped in the course of the melt-spinning of a thermoplastic synthetic fiber filament, and a fluid containing a cleaning agent such as a silicone compound is blasted toward the surface of the melt-spinning spinneret to effect the active cooling of the spinneret surface. If necessary, the stain is removed from the cooled spinneret surface, and a releasing agent such as a silicone compound is applied to the spinneret surface to facilitate the cleaning operation of the surface of the spinneret.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention cleans the melt spinneret surface by stopping the supply of polymer to the melt spinning bag during melt spinning of thermoplastic synthetic fiber yarn. Concerning how to do this.

[Prior Art] Melt spinning of thermoplastic synthetic polymers such as polyamides and polyesters is generally carried out by melting the polymer to form a molten polymer, metering the molten polymer with a metering pump, and feeding it into a melt spinning pack. , passing through a filtration layer in the spinning bag,
This is done by discharging from a spinneret.

On the surface of the spinneret used for this melt spinning, that is, on the spinneret surface, dirt from monomers, polymers, etc. adheres and accumulates, resulting in a decrease in mold release properties on the spinneret surface. The fraying phenomenon increases over time, resulting in more thread breakage. Therefore, it is necessary to periodically clean the spinneret surface even during spinning.

Therefore, in order to extend the cleaning cycle of the mouthpiece surface, it is widely practiced to apply a mold release agent such as silicone to the mouthpiece surface. However, even if such measures extend the cleaning cycle of the cap surface by only about 5.6 days,
Moreover, emptying the molten polymer in the spinning bag each time the spinneret surface is cleaned causes a large loss of polymer and is difficult to employ. Therefore, it is necessary to perform cleaning work on the mouth surface while winding is interrupted. If the spinneret surface is cleaned in this way during spinning, the polymer will be discharged discontinuously or continuously during the cleaning process, so the discharged polymer will easily fall onto the spinneret surface and it will be difficult to finish the spinneret sufficiently. It's difficult.

In addition, since cleaning must be carried out under such conditions that the polymer continues to be discharged, it is difficult to mechanize the cleaning of the mouthpiece surface, and cleaning work is widely performed by skilled hands. There is a problem in that the finished product after oxidation varies widely depending on the work H, and furthermore, the work must be completed quickly, requiring a considerable amount of manpower.

[Intervals and Points to be Solved by the Invention] Therefore, the present invention provides a method that makes it possible to easily clean the spinneret surface even if the spinneret surface is cleaned during melt spinning, and to finish the spinneret surface sufficiently cleanly. The main object of the present invention is to provide a method for cleaning the mouthpiece surface that can reduce the frequency of thread breakage after cleaning.

Another object of the present invention is to provide a cleaning method that makes it possible to stop the polymer discharge during the cleaning operation without emptying the inside of the spinning bag, and to perform the machine-based nozzle surface cleaning operation.

Means for Solving Problems] In order to achieve these objects, the present invention provides a method for cleaning a melt spinneret surface during melt spinning of a thermoplastic synthetic fiber yarn. Cleaning of the melt spinneret surface prior to cleaning by stopping the supply of polymer to the melt spinneret pack and actively cooling the melt spinneret surface by spraying fluid onto said melt spinneret surface. It consists of methods.

The method of the present invention is widely applicable to melt spinning of melt-spun polymers such as polyamides and polyesters represented by polycapramide, polyhexamethylene adipamide, polyethylene terephthalate, and polybutylene terephthalate.

[Function] In the spinneret surface cleaning method according to the present invention, first, the supply of polymer to the spinning bag is stopped and active cooling is performed by spraying fluid onto the spinneret surface, and then the spinneret surface cleaning operation is performed. This is what we do. That is, before the mouthpiece surface cleaning work, active cooling is performed by spraying fluid onto the mouthpiece surface while the polymer supply is stopped.

What is the fluid used to spray onto the mouthpiece?

For cooling the mouth surface, a substantially unheated gas (e.g.
Air at room temperature, nitrogen, etc.) is sufficient, but in order to enhance the cleaning effect of the mouthpiece surface, a cleaning agent may be mixed with these gases. Examples of the cleaning agent include silicone compounds, naphthalene, and the like. In addition, due to the workability of spraying, the fluid may be gas or
A mixture of gas and liquid is preferred.

These fluids are squeezed and sprayed under pressure onto the mouth surface.

This actively cools the nozzle surface and lowers the temperature of the nozzle surface, but this fluid spraying also stops polymer discharge from the spinning bag at least while cleaning the nozzle surface. It is sufficient as long as it is possible to do so. The amount and temperature of the fluid used for the spraying may be determined based on the temperature of the polymer in the spinning bag, the capacity, the pressure nozzle, the diameter and number of the discharge holes of the spinneret, or the ambient temperature. For example, when polyamide is melt-spun using a conventional method, 1.0 to
Room temperature air pressurized to about s, a% 100~2004
Just spray it to a certain extent.

If polymer continues to be supplied to the spinning bag even after cooling the spout surface by this fluid spraying, it will not be possible to stop the polymer discharge from the spinning bag, so fluid spraying must be performed while the polymer supply is stopped. There is.

In order to completely clean the mouthpiece surface, first remove the dirt adhering to the mouthpiece surface by scraping it off with a blade-like metal member made of metal such as aluminum or copper, or by pressing the entire rotary body against the mouthpiece surface. It is necessary to remove it by mechanical polishing means or the like. After removing this dirt, a mold release agent such as a silicone compound is usually applied on the mouth surface.
Cleaning work is completed. This cleaning work may be done mechanically or manually, and usually
This can be done within several seconds, and within 20 seconds at the most.

After cleaning the mouthpiece surface in this way,
The supply of polymer to the spinning pack may be restarted, and then spinning and winding may be restarted.

[Example (and comparative example)]

Polycapramide? Melt this molten polymer? 46'/
,, ), 20 o% was fed into the spinning pack, and 0.
A nylon 6 yarn of 70 denier and 24 filaments was obtained by spinning from a 25 mm diameter, 24 discharge holes, oiling, and taking up one winding in the usual manner. At this time, the temperature inside the spinning puncture was 265°C, and the atmospheric temperature in the spinning chamber was 28°C. Furthermore, the mouth surface was completely coated with methyl silicone oil.

In the middle of this melt spinning, inside the spinning pack? Cleaning the mouthpiece surface without emptying it? , carried out by various methods. The frequency of yarn breakage immediately below spinning after cleaning (number of yarn breakages per batch, 7 days) was investigated over time, and the degree of finish on the spinneret surface after cleaning was evaluated.

In Examples Al~3, the polymer feed to the spinning pack was stopped and then 1.5'% cold compressed air 16011
! Immediately after spraying, the cleaning work was carried out either by machine or by hand.

On the other hand, in Comparative Example 1, air blowing and manual cleaning were performed in the same manner as in Examples 1 and 2, except that the supply of reamer to the spinning puncture was not stopped. =! Ta,
In Comparative Examples 2 to 4, two operations were performed in the same manner as Examples 1 to 3, except that the two air blowing operations were not performed, including stopping the polymer supply and cleaning by hand or machine.

In addition, the cleaning work on the cap surface should be done with methyl silicone after removing the dirt attached to the cap surface. This was done by spraying. At this time, if the dirt attached to the cap surface is removed manually, it is done by scraping the dirt on the cap surface with an aluminum knife-like member, while if it is done by machine,
This was done by polishing with a rotating body.

As is clear from the results in Table 1, in the case of the method of the present invention, the spinneret surface cleaning work could be carried out without polymer discharge, so there was almost no yarn breakage immediately below spinning after spinning was resumed. , the ferrule surface was nicely finished. In addition, it was also possible to clean the cap surface using a machine.

On the other hand, even if air was blown twice without stopping the polymer supply (Comparative Example 1), the temperature of the nozzle surface hardly decreased and the polymer discharge could not be stopped, so it was difficult to finish the nozzle surface sufficiently. could not.

Further, even when the polymer supply was stopped, the polymer discharge did not stop unless air was blown twice (Comparative Examples 2 to 4), and there was no cleaning effect even if the mouth surface was cleaned. In particular, when using a machine, the spinneret surface was so dirty that it was impossible to even spin yarn.

In addition, differences in data between Examples 1 and 2 and Comparative Examples 2 and 8
′ data differences are due to differences in workers.

〔Effect of the invention〕

If the cleaning operation 2 of the mouthpiece surface is carried out by the method of the present invention, the finish of the mouthpiece surface will be sufficiently clean, so that the frequency of thread breakage after cleaning can be significantly reduced. Moreover, since the cleaning work becomes easy, a sufficiently clean finish can be achieved without requiring skilled hands, and the mouth surface cleaning work 2 can also be performed by a machine.

That is, the method of the present invention is particularly useful for automating the mouthpiece surface cleaning work.

Claims (1)

[Claims] In the method of cleaning the melt spinneret surface during melt spinning of thermoplastic synthetic fiber yarn, the supply of polymer to the melt spinning pack is stopped and the fluid is removed before cleaning the melt spinneret surface. A method for cleaning a melt spinneret surface, comprising actively cooling the melt spinneret surface by spraying onto the melt spinneret surface.