JPH03213505A - Method for forming filament - Google Patents

Abstract

PURPOSE:To carry out filament forming in good productivity by applying supersonic vibration to a die and a nozzle member having an extrusion port and increasing the flow property of forming material in the die and the nozzle. CONSTITUTION:Supersonic wave is generated in supersonic vibrator 4 by supersonic oscillator 5 and vibration is applied to a die 1 and nozzle member 2 and the die 1 and/or nozzle member 2 is allowed to resonate and a forming material is extruded from extrusion port 2a of nozzle member and the drawn under tension.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for forming filaments, and in particular to a method for forming filaments that have excellent tensile strength and less yarn breakage.

The filament molding method of the present invention can be used in any molding method in which a fluidized molding material is passed through a die or nozzle and stretched under tension in order to form a fiber.

[Conventional technology] Molding materials such as plastic, pitch, and ceramics,
For methods of forming thin linear or continuous filaments into filaments, such as extrusion molding, ■ When the melt viscosity of the molding material is high or when extrusion speed is increased, ■ Ultra-thin filaments can be formed. or (2) When the frictional resistance between the molding material and the die surface or nozzle surface is large, it is necessary to extrude and feed the filament-shaped molding material from the nozzle while applying a very large pressure.

[Problems to be Solved by the Invention] However, when a filament is extruded from a nozzle while applying a large pressure, a phenomenon occurs in which the diameter of the filament becomes larger than the diameter of the extrusion port. It will be difficult to get a 1-. In addition, due to the harassing effect, it is possible to cause sagging mucus (extrusion 11
There is also the problem that the filaments 1 to 1 are likely to break due to the phenomenon in which the molding material adheres to the vicinity of the outside of the filaments.

In order to solve these problems, it is necessary to reduce the material feed rate from the extruder or stop the molding equipment to frequently remove mucus, which is a major problem that prevents productivity from being improved. There was a problem.

The present invention was made in view of the above problems, and by effectively applying ultrasonic vibrations to a die, the vibrations are efficiently transmitted and the fluidity of the molding material in the die and/or nozzle is improved. To provide a filament forming method that enables forming thin filaments in a low temperature range by reducing the tightening and harassing effects, prevents the occurrence of eye mucus, and dramatically improves the productivity of filament forming. With the goal.

[Means for Solving the Problems] In order to achieve the above object, the filament forming method of the present invention includes a die and a nozzle member having an extrusion port, or a nozzle member having an extrusion port, in a method of forming a molding material into a filament shape. This is a method in which a molding material is extruded while only the nozzle member resonates, and then this molding material is stretched and stretched.

Preferably, the extrusion port of the nozzle is aligned with the resonant abdomen so that the effect of vibration can be expressed efficiently, and the molding is performed while minimizing the frictional resistance between the molding material and the inner surface of the nozzle.

More preferably, the filament forming method is
In order to carry out this method, the holding part of the die and the inlet of the molding material into the die are aligned with the resonance nodal part to carry out the molding.

[Example] Examples of the present invention will be described below.

First, an embodiment of the molding apparatus will be described with reference to FIG.

In the figure, numeral 1 denotes a cylindrical die, in which a die member 1a and a die member 1t+ are threadedly connected. Reference numeral 2 denotes a nozzle member 2 having a plurality of extrusion ports 2a, and is fixed to the die member 1b with bolts 3. The shape 9 dimensions, number, and arrangement position of the extrusion port 2a of this nozzle member 2 are as follows:
It can be arbitrarily selected depending on the filament to be molded.

The die 1 and the nozzle member 2 can be made of various materials such as metal materials conventionally used in extrusion molding, ceramics, and graphite. It is preferable to use materials with low transmission loss, especially duralumin and titanium alloys.

K-monel, phosphor bronze, graphite, etc. are preferred.

Further, as shown in FIG. 2, the die 1 and the nozzle member 2 are connected to each other so as to resonate. in this case,
What kind of shape may be used for the bonding surface between the die member 1b and the nozzle member 2? In order to transmit and achieve good resonance,
It is preferable that the joint surface coincides with the abdomen of the displacement resonance (the point where the farthest part of the displacement waveform vibrates most strongly).

The die 1 and the nozzle member 2 can be constructed as a plurality of divided members, and in this case, they may be made of the same material or of different materials. Furthermore, the die 1 may be subjected to various plating treatments or coating treatments to improve its wear resistance, corrosion resistance, or to lower the coefficient of friction with the molding material, and to prevent thread breakage, it may be coated with boron nitride, etc. It is also possible to apply a mold release material.

Moreover, it is also possible to equip the die l with a mechanism for changing the direction of vibration. For example, the L-L converter conventionally used in the case of ultrasonic vibration.

It is possible to provide the die 1 with a converter such as an L-R converter or an L-L-L converter.

Furthermore, the resonance may be caused by causing the die 1 and the nozzle member 2 to resonate, or by causing only the nozzle member 2 to resonate (see FIGS. 6 and 7). However, by making both the die 1 and the nozzle member 2 resonate, it is possible to extrude only at a low temperature, so that a filament with higher strength can be obtained.

In the resonant state, most parts of the die 1 or the nozzle member 2 vibrate, so if a conventional plate heater is attached, there is a risk that the wiring inside the plate heater may be broken by the vibration.

Therefore, for heating the dice 1, it is preferable to use a far-infrared heater (not shown) that can heat the dice 1 without having to come into contact with them. In this case, make sure that the heater comes into contact only with the resonance node (the point where the displacement waveforms intersect and are not vibrating), and fix the die l and the far-infrared heater at that node using screws, etc. do.

Reference numeral 4 denotes an ultrasonic vibrator, which applies vibration to the die 1 and the nozzle member 2 and is coupled to a position where it resonates. In addition to this ultrasonic vibrator 4, an electrodynamic or electrohydraulic type device can be used as a vibration generator that causes the die 1 and the nozzle member 2 to resonate.

It is also possible to incorporate a vibration transmitting body between the die l and the ultrasonic vibrator 4, and if the shape of the vibration transmitting body is appropriately selected, the amplitude of the vibration generated by the ultrasonic vibrator 4 can be adjusted. can be easily increased or decreased. Ultrasonic transducer 4
In order to easily transmit the vibration generated by the ultrasonic transducer 4 to the die 1 with high efficiency, the contact portion between the ultrasonic transducer 4 and the die 1 must be set to the part of the die l that vibrates with the largest amplitude in the resonant state, that is, the part of the die l that vibrates with the largest amplitude. Preferably, it coincides with the abdomen.

The number of ultrasonic transducers 4 coupled to the dice l is
Although not particularly limited, when a plurality of them are combined, it is necessary to adjust the timing of vibration so that the resonance state of the dice 1 is not disturbed. The more ultrasonic vibrators 4 are coupled, the more strongly the die 1 can be vibrated.

Reference numeral 5 denotes an ultrasonic oscillator, which causes the ultrasonic vibrator 4 to generate ultrasonic waves and excite it at the resonant frequency when the die 1 and the nozzle member 2 are coupled, thereby causing the die 1 and the nozzle member 2 to resonate.

The resonance frequency when the die 1 and the nozzle member 2 are combined is designed and manufactured in advance to a frequency that can be tracked by the ultrasonic oscillator 5. Therefore, the molding material is supplied to the die 1 from the extruder nozzle 6. , the system constantly tracks slight changes in the resonant frequency due to momentary load fluctuations until the molding material is finally extruded from the extrusion port 2a, and the necessary power supply is also adjusted according to momentary changes. It is set to supply the required amount (less than maximum output). That is,
Automatic frequency tracking and automatic power control methods are adopted.

6 is a nozzle of a single-screw or multi-screw extruder, and the molding material is supplied from this nozzle 6 to the die la through an inlet,
Finally, the molding material is extruded from the extrusion port 2a. Here, the extrusion port 2a is designed as a resonant abdomen in order to maximize the effect of vibration. Furthermore, it is also possible to provide a static mixer between the die 1a and the extruder.

Further, the nozzle 6 is fixed at the position of the resonant knob of the die 1a by a mounting means such as a screw. In this way, vibrations can be hardly transmitted to the nozzle 6. Furthermore, in order to suppress the transmission of vibration to the nozzle 6, it is preferable to incorporate a cushioning material such as titanium alloy fiber into the contact portion between the nozzle 6 and the die la.

When molding a composite filament using a plurality of molding materials, a plurality of nozzles 6 may be provided.

The extrusion direction of the molding material extruded from the extrusion port 2a of the nozzle member 2 and the direction of the vibration transmitted through the extrusion port 2a are not limited in any way, but the dispersion and agitation of the molding material by vibration at the extrusion port 2a is not limited in any way. If extrusion is also carried out, it is preferable that the extrusion direction and its vibration direction be perpendicular.

Further, if the shape resonates, the effect of vibration of the extrusion port 2a can be increased or decreased by changing the shape of the extrusion port 2a. For example, if vibration is transmitted in the extrusion direction and the extrusion port 2a is shaped linearly, zero or functionally narrowed, the amplitude, that is, the effect of vibration can be increased at the extrusion port 2a. By having such a shape, it is possible to generate a driving force due to vibration in the extrusion direction, and it is possible to extrude thermoplastic materials well even at low temperatures where fluidity is low, as long as the temperature is above the glass transition temperature. .

7 is a drawing device for drawing, and the extrusion port 2a of the nozzle member 2
The filament-like extrudate that has been extruded is taken out while being stretched under a constant tension.

Next, an embodiment of a filament forming method performed using the above-mentioned forming apparatus will be described.

A nozzle 6 of a molding machine (not shown) is connected to the die la, a molding material is supplied to the die 1 to mold the filament, and an ultrasonic oscillator 5 generates ultrasonic vibrations in the ultrasonic vibrator 4. The dice 1 and the nozzle member 2 are caused to resonate at n wavelengths (n=m/2: m is a positive integer).

The vibration frequency at this time can be arbitrarily selected or may be normally set to 10 Hz to 10 MHz. In order to make the vibration effect extremely effective on the fluidized material, it is preferable to use a frequency of 10KH to 100KH.

In the n-wavelength resonance, n is preferably m/2 as described above (Fig. 3), or n < 3 in order to reduce the loss of ultrasonic vibration in the die 1 and the nozzle member 2. .

Further, the amplitude of the ultrasonic vibration applied to the die 1 is preferably 0.1 JLm to 1100 p in order to improve the fluidity and dispersibility of the molding material and to increase the driving force due to the vibration.

The filamentary extrudate extruded from the nozzle member 2 is then subjected to a stretching process. The stretching process may be set so that the ratio of the extrusion speed and take-up speed of the extrudate from the extrusion port, that is, the draft ratio, is greater than 1 time and less than 1,000 times. In addition, cooling, heat treatment 9 surface treatment, etc. can be performed by known methods. For example, the degree of crystallinity of the filaments of the crystalline resin can be increased by high-frequency heating of the extrudate.

Examples of the surface treatment include resin treatment, permanent press treatment, antistatic treatment, sweat absorption treatment, moisture permeable waterproof treatment, antifouling treatment, flame retardant treatment, corrosion prevention treatment, antibacterial and deodorization treatment, and the like.

Note that in this specification, filaments include not only general fibers, but also structural crimped fibers and hollow fibers.

Conjugate fibers, high shrinkage fibers, high strength fibers.

Medical fibers 2 Synthetic paper fibers, spunbond fibers.

Fibers for artificial leather 9 Includes fibers for separation membranes, etc.

As the molding material that can be molded by the above-described filament molding method, the following can be used.

■Thermoplastic resin α-olefin resin (polyethylene, polypropylene, polystyrene, syndiotastic polystyrene,
Vinyl chloride resin, bolybdenum, ultra-high molecular weight polyethylene, polymethylpentene, ionomer, polybutylene, etc.) Polyester resin (polyethylene terephthalate, polyethylene terephthalate, polyarylate, etc.) Polyether resin (polysulfone, polyethersulfone, polyester resin, etc.) Etherketone, polyetheretherketone, polyallyl sulfone, polyoxybenzylene, polyphenylene oxide, polycyanoallyl ether [JP-A-62-22326], etc.) Polycarbonate resin Polyimide resin Polyamide resin Polyamide-imide resin Methacrylic resin Fluorine Resin MBS (methacrylate butadiene styrene) resin AAS (acrylate acrylonitrile styrene) resin AS (acrylonitrile styrene) resin AC3 (chlorinated acrylonitrile polyethylene styrene) resin ABS (acrylonitrile) resin polyacetal resin cellulose resin butadiene styrene 4 Polyvinylidene chloride chlorinated polyethylene EVA (ethylene vinyl polyurethane resin silicone resin allyl resin furan resin liquid crystal polymer, etc. Thermosetting resin epoxy resin phenolic resin polybutadiene resin silicone resin unsaturated polyester resin amino resin etc. ■ thermoplastic elastomer styrene-butadiene elastomer polyester elastomer polyethylene 5. Inorganic materials such as organic materials, pitch, inorganic polymers, ceramics including superconducting materials, metals, glass, etc. Examples include materials that have at least some fluidity during molding, such as mixed materials. In particular, if applied to plastics and pitch, it not only becomes possible to perform high-speed molding at low temperatures that would conventionally cause yarn breakage, but also allows for easy molding of ultra-fine, highly oriented filaments, and furthermore, allows for subsequent drawing. High strength fibers can be obtained by optimizing the conditions.

Furthermore, when reinforcing fibers are fed to the die together with a fluid material such as plastic, the material penetrates into the fibers due to vibration, making it possible to produce high-strength conjugate fibers without voids.

In addition, the filament forming method in the present invention includes all methods such as extrusion molding and pultrusion molding, in which the molding material in a fluid state is passed through a die or nozzle and stretched under tension in order to form a fiber. .

6 [Experimental Examples] Hereinafter, experimental examples conducted using the molding method of the embodiments of the present invention will be explained while comparing with comparative examples.

Experimental example 1 Molding equipment: equipment shown in Figure 1 Molding material: polyethylene (440M made by Idemitsu Petrochemical) Dice and nozzle parts: Material: 5US304 8 extrusion ports, 1 each. (lv$ Dice shape: cylindrical Ultrasonic oscillator dual fundamental frequency 919.15KN.

(5ONOPET1200-B manufactured by Seidensha Electronics Co., Ltd.) Amplitude: 111 Lm Vibration mode: Vertical vibration Extrusion conditions: Material temperature: 280°C Die, nozzle member temperature: 280°C Extrusion amount: 6,8 Kg/hr Take-up speed: 650 cm According to the above conditions Extrusion molding was performed while making the die and nozzle member resonate, and the frequency of yarn breakage due to mucus produced during continuous molding for 24 hours was investigated.

7 The frequency was once.

Comparative Example 1 The frequency of thread breakage due to eye discharge was investigated under the same conditions as Experimental Example 1 except that the oscillation of ultrasonic waves was stopped.

The frequency was 37 times.

Experimental Example 2 Molding apparatus: As shown in FIGS. 4(a) and 4(b), an apparatus having a structure in which the die member was horizontally elongated and an LL converter was used was used.

Content 1wt%) Take-up speed 2.5 (■/■in) Except for the above, molding was carried out under the same conditions as in Experimental Example 1 while making the die resonate, and the tensile strength of the obtained filament at 25°C was measured.

As a result, the tensile strength was 196 Kg/c2.

Comparative Example 2 8 The experiment was started under the same conditions as Experimental Example 2 except that the ultrasonic oscillation was stopped, or melt fracture occurred under the same material temperature and die temperature as Experimental Example 2. Then, I gradually lowered the material temperature and the die and nozzle member temperatures to L.
The molding material started to decompose, so the extrusion rate was reduced to 0.3K.
g/hr, and the temperature of the die and nozzle was 265°.
The experiment was conducted as C.

As a result, the tensile strength of the obtained filament at 25°C was 140 Kg/cm2.

Ta.

Content rate 1wt%) Ultrasonic oscillator: Fundamental frequency 19° 15KN□ 9 (5ONOPET 120 Low B manufactured by Seidensha Electronics Co., Ltd.) Amplitude 11gm (1lx 8.5 = 93° 5kawam at the extrusion port) Vibration mode Vertical Vibration extrusion conditions: Material temperature 200°C Die, nozzle member temperature 200'C Extrusion amount 0.0
25 Kg/hr Take-up speed 0.9 m/min Extrusion molding was carried out under the above conditions while making the die and nozzle member resonate, and the tensile strength of the obtained filament at 25°C was measured.

As a result, the tensile strength was 227 Kg/cm2.

Moreover, no melt fracture occurred in the filament at this time.

Comparative Example 3 An experiment was started under the same conditions as in Experimental Example 3 except that the ultrasonic oscillation was stopped, but at the same material temperature and die temperature as in Experimental Example 3, melt fracture significantly occurred. Therefore,
Gradually increase the material temperature, die, and nozzle member temperature 25
At 0°C, a filament without melt fracture was finally obtained.

The tensile strength of the obtained filament at 25°C is 13
It was 5 Kg/c■2.

A device as shown in FIG. 6 was used as a molding device. Then, an experiment was conducted under the same conditions as in Experimental Example 3, except that a structure in which only the cylindrical die member resonated was used, and a radial vibrator that generated radial vibration was used. FIG. 7 shows the displacement waveform of the nozzle member when it resonates. In this case, the direction of vibration of the members of the nozzle at the extrusion outlet is perpendicular to the extrusion direction of the filament. The tensile strength of the obtained filament at 25°C was measured.

As a result, the tensile strength was 200 Kg/cm''.

Moreover, no melt fracture occurred in the filament at this time.

14 The experiment was started under the same conditions as Experimental Example 4 except that the ultrasonic oscillation was stopped, but at the same material temperature and die temperature as Experimental Example 4, melt fractures occurred significantly. Therefore, the material temperature, die, and nozzle member temperatures were gradually increased to 250°C, and finally a filament without melt fracture was obtained.

The tensile strength of the obtained filament at 25°C is 1
It was 42 Kg/crs2.

[Effects of the Invention] As described above, according to the filament forming method of the present invention, by effectively applying ultrasonic vibration to the die, the vibration is efficiently transmitted, and the die and/or
Alternatively, it improves fluidity within the nozzle, reduces the balance effect, enables high-strength filament to be formed at low temperatures, and prevents thread breakage due to mucus, dramatically increasing the productivity of filament forming. can be improved.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of essential parts of an embodiment of the filament forming apparatus (used in Experimental Example 1), and Figure 2 is the resonance of the die and nozzle members in the filament forming apparatus used in Experimental Example 1. Figure 3 is an explanatory diagram of a specific example of the displacement waveform and wavelength of ultrasonic vibration in the extrusion molding method of the present invention. Figures 4 (a) and (b) are Experimental Example 2. Fig. 5 is a side view and front view of the main part of the filament forming apparatus used in Experimental Example 2, and Fig. 6 is an explanatory diagram of the displacement waveform and wavelength during resonance of the die and nozzle member in the filament forming apparatus used in Experimental Example 2. 7 is a sectional view of a main part of the filament forming apparatus used in Experimental Example 4, and FIG. 7 is an explanatory diagram of displacement waveforms and wavelengths at resonance of the die and nozzle member in the filament forming apparatus used in Experimental Example 4. 1: Dice la, lb: Dice member 2: Nozzle member 2a: Extrusion port 4: Ultrasonic vibrator 5: Ultrasonic oscillator 7: Drawing device for drawing

Claims (2)

[Claims] (1) A method for molding a molding material into a filament shape, characterized by extruding the molding material while resonating a die and a nozzle member having an extrusion port, and then stretching the molding material under tension. Method. (2) A method of forming a filament by extruding a molding material while resonating a nozzle member having an extrusion port, and then stretching the molding material under tension.