JPH0214441B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION {Field of Industrial Application} The present invention relates to a melt spinning method and apparatus.

More specifically, the raw materials for spinning originally have a wide range of molecular weight distributions, and as a result, physical properties such as melting points are not clear and there are variations in melt viscosity, etc. When heated to a molten state, it becomes a solid or gel-like material. It is easy to generate modified products and heavy compounds, it is also easy to generate gas due to thermal decomposition and polymerization, its melt viscosity is highly dependent on temperature, and it oxidizes when it comes into contact with the atmosphere in a molten state. The present invention relates to a method and apparatus for melt-spinning materials such as phenolic resins, ethylene polyvinyl alcohol copolymer resins, polyester copolymerized or blended with epoxy, polyethylene glycol, etc.

{Prior Art} Generally, in a spinning device for spinning raw materials, such as a chip melt spinning device, a melter for melting and extruding the raw material chips, a metering pump for metering the polymer extruded from the melter, and a metered polymer are introduced. It consists of a spinning pack that is discharged from a spinneret and spun.

Generally, an extruder or a pot type melter is used as the melter.

{Problems to be Solved by the Invention} However, the above-mentioned spinning raw materials have the following drawbacks.

First, among conventional extruders, a vent type extruder is generally used when it is necessary to degas gas generated by thermal decomposition or polymerization. However, due to variations in the melt viscosity and high temperature dependence of the raw materials mentioned above, the material balance of the spinning raw materials cannot be maintained between the melting section, vent section, and extrusion section of the extruder, making stable operation impossible. be.

In addition, the above-mentioned spinning raw materials are inherently prone to generating solid or gel-like heat-denatured substances or compounds, and even if the raw materials are filtered in advance, the raw materials extracted from the extruder will be heated. As heat-denatured products and compounds are generated as a result of the history, these heat-denatured products and compounds are collected as solids or gels in the subsequent spinning pack, causing a pressure increase over time, and causing long-term damage. Driving is impossible.

On the other hand, when using a pot-type melter to melt-spun raw materials that are easily decomposed, it is impossible to transport the melted raw materials while degassing them, so only batch production is possible, which is also not continuous.

The purpose of the present invention is to solve the above-mentioned conventional problems, and the spinning raw material originally has a wide molecular weight distribution, so its physical properties, such as melting point, are not clear, and there are variations in melt viscosity, etc. When heated to a molten state, solid or gel-like heat-denatured products and polymer compounds are likely to be generated.
In addition, they tend to undergo thermal decomposition, generate heavy compounds, have a high temperature dependence of melt viscosity, and are oxidized when exposed to the atmosphere in a molten state, such as phenolic resins and ethylene polyvinyl alcohol. Using materials such as copolymer resins, copolymerization or blending of polyester with epoxy, polyethylene glycol, etc. as raw materials,
It is an object of the present invention to provide a melt-spinning method and apparatus for producing high-quality long fibers by continuously melt-spinning the fibers.

{Means for solving the problem} Therefore, in the melt spinning method according to the present invention, the spinning raw material is melted and discharged by the first stage extruder, and then continuously supplied to the second stage extruder. In the melt spinning method, the gas component of the spinning raw material is extruded while being degassed, and then the gas component of the spinning raw material is measured and passed by a measuring means, and then melt-spun from a spinneret. A passing means is interposed between the extruder in the second stage to pass the melted and discharged spinning raw material, (c) the screw rotation speed of the second stage extruder is controlled to a rotation speed that is higher than the discharge amount of the first stage extruder;
The first stage extruder is controlled to a constant rotation speed, and the discharge pressure of the second stage extruder is detected on the upstream side of the measuring means so as to keep the discharge pressure constant. (d) controlling the heating temperature of the spinneret to a higher temperature than the heating temperatures of the measuring means and the passing means, and performing melt spinning from the spinneret. This is a spinning method.

Furthermore, the melt spinning apparatus according to the present invention includes a first-stage extruder having a spinning raw material feed function and a melting function, and a discharge section of the first-stage extruder having a supply section for the spinning raw material. a second stage extruder having a venting function and an extrusion function, in which the extruders are connected in series;
Melt spinning comprising a spinning block connected to the discharge section of the second stage extruder and incorporating a measuring means and a passing means for the spinning raw material, and a spinneret connected to the lower end of the block. In the apparatus, (a) a means for passing the spinning raw material interposed between the discharge part of the first stage extruder and the supply part of the second stage extruder, and (b) the second stage extruder. (c) rotational speed control means for making the discharge amount of the second extruder more than the discharge amount of the first extruder; (c) the first extruder provided upstream of the measuring means a discharge pressure detection means for detecting the discharge pressure of the second-stage extruder; (d) the screw rotation speed of the second-stage extruder is kept constant, and said first so as to keep the discharge pressure constant.
(e) discharge pressure control means for controlling the screw rotation speed of the extruder in each stage; (e) means for controlling the heating temperature of the spinneret to a temperature higher than the heating temperature of the measuring means and the heating means A melt spinning apparatus characterized by comprising: heating control means for the spinneret.

Further preferred embodiments of the present invention will become clearer in accordance with the following description.

Hereinafter, the melt spinning method and apparatus of the present invention will be explained in more detail based on the drawings.

The figure is a schematic diagram illustrating a preferred embodiment of the melt spinning apparatus of the present invention.

In this figure, illustration of the barrel portions of the extruders 1 and 2 and heating means for the connecting pipes 19 and 20 is omitted.

In the figure, the spinning raw material 4 is fed to the extruder 1 in the first stage.
It is first stored in the hopper 5 which can store the required amount in the form of chips or powder of an appropriate size that can be easily bitten into the screw 6.

The first stage extruder 1 has the function of feeding the spinning raw material 4 from the lower part of the hopper 5 by rotating the screw 6 and melting it. The second stage extruder 2 has a vent hole 9 in the barrel portion, and has an extrusion function on the tip side of the screw 7 from the vent hole 9. The discharge part of the first stage extruder 1 and the second
The feed section of the extruder in the third stage is connected in series with a connecting pipe 19. A spinning block 10 is connected to the discharge side of the second stage extruder 2 through a connecting pipe 20,
The polymer passage 21 has a metering means, for example a gear pump 11, in the middle of the polymer passage 21 up to the spinneret 14, and a passing means (A) 12 between the spinneret 14 and the metering means 11.

In addition, heat-denatured products, heavy compounds, etc. generated in the first-stage extruder 1 are removed from the connecting pipe 19 between the first-stage extruder 1 and the second-stage extruder 2. In order to
(B)8 is provided.

Further, the heating means 18 of the spinneret 14 is configured independently of the heating means 16 of the spinning block 10, and furthermore, the means 17 for heating the spinning means (A) 12.
is preferably constructed independently of the heating means 16, 18.

In addition, the measuring means 11 and the measuring means (A) 12
It is more preferable to insert kneading means, for example, several stages of static mixers 26 between the mixing steps.

Furthermore, the rotation speed of the screw 7 of the second stage extruder 2 is controlled at a constant rotation, and the discharge pressure of the second stage extruder 2 is detected upstream of the gear pump 11. A detection means (not shown) is provided, and each control function of a discharge pressure control means (not shown) that controls the rotation speed of the screw 6 of the first stage extruder 1 so as to keep the discharge pressure constant. It is provided.

When producing fibers with the configuration described above, the operating conditions of the second-stage vent type extruder 2 are to operate at a screw rotation speed that causes the discharge amount to be higher than the discharge amount of the first-stage extruder. , that is,
It is important to control the screw rotation speed of the second stage extruder 2 by a rotation speed control means (not shown).

That is, when melt-spinning the spinning raw materials as described in the purpose section, the extruder is used as a first-stage extruder 1 having a feed function and a melting function, and a second-stage extruder 1 having a vent function and an extrusion function. By dividing the functions into machine 2, each function can be controlled independently. Fluctuations in discharge pressure of machine 2 and gear pump 1
The discharge pressure fluctuations and the like from before are eliminated. Also, the first
Passing means to the connecting pipe 19 of the extruder of the stage and the second stage
(B) 8, the second stage extruder 2 and the spinneret 14
By providing a metering means 11 between the metering means 11 and another passing means (A) 12 between the metering means 11 and the spinneret 14, the passing means (B) 8 is located upstream of the vent hole 9. Since the passing means (A) 12 is located on the downstream side of the metering means, for example, the gear pump 11, the spinning raw material undergoes thermal history to produce a solid or gel-like heat-denatured product or a polymer compound. Or even if the pressure rises over time due to being collected by the excess means in (B),
As long as the operating conditions of the second stage extruder 2 are operated at a screw rotation speed that results in an excess discharge amount than the discharge amount of the first stage extruder 1, the second stage extruder 2
Since the back pressure of There is no blockage (9) and stable long-term operation is possible (while continuously removing heat-denatured products and heavy compounds). At that time, by providing the control function as described above,
Stable long-term operation can be achieved automatically.

Furthermore, by configuring at least the heating means 18 of the spinneret 14 independently of the heating means 16 of the spinning block 10, the optimum temperature for spinning can be selected within a certain range independently of the heating block 10; For spinning raw materials that tend to generate heat-denatured products, heavy compounds, and gases when subjected to thermal history as the object of the present invention, the temperature in the spinning block 10 etc. is kept as low as possible to suppress the generation of the above substances. Then, the set heating temperature of the spinneret 14 is set to the highest temperature among the set heating temperatures from the discharge port of the second stage extruder 2 to the spinneret, that is, the heating temperature of the spinneret 14 is set to the spinning block. The spinning is performed by controlling the temperature to be higher than the heating temperature of the measuring means 11 and the passing means 12 in the spinning means 10.

Furthermore, by having the overheating means (A) 12 also with an independent heating means 17, the overheating can be controlled within a certain range depending on the temperature. For example, if the temperature is increased, the viscosity of the gel-like material decreases and it slips through the passing means, so it is preferable that the temperature and pressure be lower. By disposing the second passing means 12 upstream of the distribution plate 13 immediately in front of the spinneret 14, the molten raw material is evenly distributed to the back surface of the spinneret 14, and the back pressure of each discharge hole of the spinneret 14 is equalized. turn into something.

Furthermore, the measuring means 11 and the measuring means (A) 12
By providing a kneading means, for example, a static mixer 26 between the steps, the molten raw material can be kneaded by itself without increasing the discharge pressure of the second stage extruder 2, and the physical properties of the raw material can be homogenized. Can improve yarn reeling properties.

In the above configuration, the second stage extruder 2 is operated at a screw rotation speed at which the discharge amount is larger than the discharge amount of the first stage extruder 1, that is, in a starvation state. Since the groove space of the screw 7 of the extruder 2 in the stage is not filled with the raw material, even if the discharge pressure of the extruder 2 fluctuates due to viscosity unevenness, the discharge pressure moves to the upstream side in the groove space. No ripples,
Stable spinning is possible without vent-up.

In addition, depending on the raw material, it may be possible to degas the vent hole 9 at atmospheric pressure without actively degassing it, but it is preferable to degas it by drawing a vacuum to below atmospheric pressure. . In addition, for raw materials that are oxidizing in the molten state, vacuuming may cause the atmosphere to leak in and come into contact with the raw material, accelerating oxidation. ,
For example, while introducing N ₂ , Ar, He, etc. through the gas introduction hole 24 shown in the figure, it is preferable to evacuate the material together with the generated gas components of the raw material through the exhaust port 25 to a pressure below atmospheric pressure.

In addition to the above, in the melt spinning of raw materials having oxidizing properties as described above, at least the screw end of the second stage extruder 2, preferably the first
The screw end of the extruder 1 in the stage is also directly below the spinneret 14, the gear pump 11 and the spinning block 10.
It is important to perform spinning while maintaining the atmosphere around the parts where the raw material may come into contact with the atmosphere in a molten state in a non-oxidizing gas atmosphere, as well as the contact surface with the raw material.

Furthermore, since raw material 4 also contains air and moisture,
After closing the on-off valve 27, the raw material 4 is put into the hopper 5, the inside of the hopper is evacuated from the exhaust hole 23, and then a non-oxidizing gas is supplied from the gas supply hole 22 to restore it to atmospheric pressure. 3-4
After reducing the oxygen concentration in the hopper 5 by repeating the process several times, the on-off valve 27 is opened to start operation, and during operation, the exhaust port 23 is closed and the gas supply hole 22 is opened to prevent oxidation. It is preferable to perform spinning while applying the gas pressure of the reactive gas to atmospheric pressure or higher.

As described above, the present invention is particularly effective for melt spinning of materials such as those described in the object section, but is not suitable for melt spinning of general synthetic fibers such as polyester, nylon, etc. Needless to say, it is effective.

〔Effect of the invention〕

Since the present invention is configured as described above, it has the following effects. In other words, the functions of feeding, melting, venting, and measuring the spinning raw material are divided and arranged at appropriate positions by the first stage extruder, second stage extruder, measuring means, etc. Each function can be controlled individually, allowing stable operation without fluctuations in discharge pressure or vent-up.

The spinning raw material melted in the first-stage extruder is passed through a filtration means and then supplied to the second-stage extruder. Compounds and the like are removed, clogging of the measuring means and spinneret are prevented, and high quality long fibers can be obtained.

Since the screw rotation speed of the second stage extruder is operated under conditions where the discharge amount is higher than the discharge amount of the first stage extruder, even if the viscosity unevenness of the spinning raw material Even if the discharge pressure of the extruder fluctuates or the pressure of the passing means provided in front of the spinneret increases over time, the back pressure of the second stage extruder 2 does not increase, so no venting occurs. Stable melt spinning can be continued without any problems.

In addition, at this time, the screw rotation speed and discharge pressure of the second stage extruder are controlled to be constant, so that a constant amount of spinning raw material is always sent to the metering means, and The discharge pressure of the extruder becomes stable, and vent-up from the second-stage extruder is further eliminated, allowing stable operation over a long period of time.

Since it has appropriate control functions such as rotational speed control means, discharge pressure control means, and heating control means, the spinning raw material is free from variations in melt viscosity, heat-denatured products, and heavy compounds as mentioned in the purpose section. Even if it is a special type of vehicle, trouble-free and stable automatic operation can be achieved.

At least the heating means for the spinneret is provided independently from other heating means, so melt spinning can be performed under temperature conditions that minimize the generation of heat-denatured products, polymers, gases, etc. of the spinning raw material after venting, resulting in high quality. Long fibers are obtained.

[Brief explanation of drawings]

The figure is a schematic diagram showing an example of an embodiment according to the present invention. Explanation of symbols in the drawings: 1: first stage extruder;
2: Second stage extruder, 3: Spinning head, 4: Spinning raw material, 5: Hopper, 6: First stage screw, 7: Second stage screw, 8: First stage screw. means, 9: vent hole, 10: spinning block,
11: Gear pump, 12: Second stage overloading means,
13: Dispersion plate, 14: Spinneret, 15, 16, 1
7, 18: heating means, 19, 20: connecting pipe, 2
1: Polymer passage, 22, 24: Gas supply hole, 2
3, 25: Exhaust port, 26: Static mixer, 27:
Opening/closing valve, 30: Reduction device, 31: Drive motor.

Claims (1)

[Claims] 1. Melting and discharging the spinning raw material with a first stage extruder,
In the melt spinning method, the gas components of the spinning raw material are then extruded while being degassed by being continuously supplied to a second stage extruder, and then the raw material is metered and filtered by a metering means, and then melt spun from a spinneret. (b) A passing means is interposed between the first stage extruder and the second stage extruder to pass the melted and discharged spinning material; (b) the second stage extruder (c) controlling the screw rotation speed of the second stage extruder to such a speed that the discharge amount of the extruder is greater than the discharge amount of the first stage extruder; the number,
The first stage extruder is controlled to a constant rotation speed, and the discharge pressure of the second stage extruder is detected on the upstream side of the measuring means so as to keep the discharge pressure constant. (d) controlling the heating temperature of the spinneret to a higher temperature than the heating temperatures of the measuring means and the passing means, and performing melt spinning from the spinneret. Spinning method. 2. A first-stage extruder having a spinning raw material feed function and a melting function, and a vent function in which the spinning raw material supply section is connected in series to the discharge section of the first-stage extruder. a second-stage extruder having an extrusion function; a spinning block connected to the discharge section of the second-stage extruder and incorporating a measuring means and a passing means for the spinning raw material; In a melt spinning apparatus equipped with a spinneret connected to the lower end, (a) a spinneret interposed between the discharge part of the first stage extruder and the supply part of the second stage extruder; (b) rotational speed control means for making the discharge amount of the second stage extruder more than the discharge amount of the first stage extruder; (c) (d) a discharge pressure detection means for detecting the discharge pressure of the second stage extruder, which is provided upstream of the measuring means; and (d) a screw rotation speed of the second stage extruder. and the discharge pressure determined by the discharge pressure detection means is made constant.
(e) discharge pressure control means for controlling the screw rotation speed of the extruder in each stage; (e) means for controlling the heating temperature of the spinneret to a temperature higher than the heating temperature of the measuring means and the heating means A melt spinning apparatus comprising: heating control means for the spinneret;