JPH0571058A - Production of fiber formed product - Google Patents

Abstract

PURPOSE:To obtain a fiber formed product having uniform network structure and stabilized in quality by heating a fiber bundle obtained by mixing synthetic fibers having different melting point from the central part by microwave and further heating the peripheral part by hot air. CONSTITUTION:A fiber bundle obtained by mixing synthetic fibers having different melting point is passed through the interior of an applicator of microwave and heating from the fiber central part is carried out by the microwave. The fiber bundle is further heat-treated by passing the fiber bundle through a hot air heater and the peripheral part is heated to provide the fiber formed product suitable for ink occlusion body for marking pen, occlusion body of cosmetic solution, suction wick for aromatic, dental mouse piece, cigarette filter, etc.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention can be applied to ink occluding bodies for marking pens, occlusion bodies for cosmetic solutions, wicks for fragrances, dental mouthpieces, cigarette filters and various fibers. The present invention relates to a method for manufacturing a fiber molded product that provides a bundle.

[0002]

2. Description of the Related Art Conventionally, an ink occlusion body for a marking pen has a heat-meltable crimped short fiber and crimped short fiber having a melting point higher than that of the fiber to form a fiber bundle. Alternatively, it was manufactured by heating with far infrared rays or the like.

[0003]

However, in the above-mentioned method, there are few problems when producing an occlusion body having a small diameter, for example, 5 mmφ or less, but an occlusion body having a diameter larger than that, for example, about 20 mmφ is produced. In this case, there are the following problems. (1) Since the heat is applied from the outer peripheral portion of the fiber bundle, the heat-meltable crimped short fibers are melted in the outer peripheral portion of the fiber bundle,
Although the fibers are bonded (spot-bonded) to each other, the above-described point-bonding is insufficient because heat is not sufficiently transferred / supplied in the central portion of the fiber bundle. That is, a relatively dense net-like structure is formed in the outer peripheral portion of the fiber bundle, and a relatively coarse structure is formed in the central portion, resulting in non-uniform osmotic pressure.
The ink tends to migrate to the outer periphery. Therefore, there is a drawback that the flow of ink from the pen tip that is joined to the essential center becomes unstable. In addition, since the central portion of the fiber bundle is almost untreated, the fibers are not constrained by the fibers due to point-bonding as in the outer peripheral portion, which causes a slip phenomenon due to impact. (2) The heat conductivity of the fiber itself is low, and since voids are present, the heat insulating effect is high and the rate of heat rise is low. Therefore, the heat treatment takes a long time and the productivity is poor. Incidentally, if the heating temperature is raised, the heating time can be shortened to some extent, but there is a limit to the heating temperature due to the possibility of heat deterioration (softening) of other fibers, so that a great effect can be obtained. Can not. (3) Since it is necessary to first heat the heating device itself, for example, the heating furnace, wasteful energy (consumed in addition to heating the object to be heated) is required, resulting in high cost and not meeting the user's request. There were many things that did not exist.

[0004]

The present invention has been proposed in view of the above, and a fiber bundle formed by mixing synthetic fibers having different melting points is heated from the center in a microwave heating step, and then hot air is blown. The present invention relates to a method for producing a fiber molded product, characterized in that the fibers are partially heat-sealed by heating the outer peripheral portion in the heating step.

As described above, according to the present invention, a fiber bundle formed by mixing synthetic resins having different melting points is heat-treated to heat-melt the low-melting-point fibers and heat-bond (fiber-bond) the fibers together. It is a thing. Then, at that time, by adopting microwave heating as the heating means, high-speed and uniform point bonding is performed.

When a heat-melting fiber (derivative) is passed through an electric field of microwaves, the dipole vibrates and vibrates violently due to the electric field of microwaves, and the friction itself causes the dielectric itself to generate heat. The heat treatment using microwaves described above has the following features. The high-speed heating microwave instantaneously penetrates into the object to be heated and converts heat energy, so that the time required for heat conduction is extremely short and heat is generated in a few seconds to a few minutes. High-speed response performance Microwave energy has a light velocity (3 × 10 ⁸ m /
Since it has a high-speed response performance conducted in c), it is possible to easily control instantaneous start / stop and output adjustment. Uniform heating Since heat is generated from the central part of the object to be heated, it is possible to uniformly heat the inside thereof. High thermal efficiency Since the object to be heated itself becomes a heating element, there is no need to heat the surrounding air or heating furnace, so there is no energy loss. Therefore, high thermal efficiency can be obtained and energy saving can be achieved.

In the manufacturing method of the present invention, first, the fibers are preheated by a jet hot air preheating device (80 to 100 ° C.) before entering the microwave applicator. Next, it is passed through a microwave applicator and heated from the center of the fiber by microwaves. The heating status is adjusted by the microwave output. After that, heat treatment is performed by passing hot air (around 110 ° C.) through a heating device. The obtained fiber bundle is coated with a polyester film or an outer cover made of a non-woven fabric in order to prevent the ink from flowing out from the outer peripheral surface when it is used as an ink absorber.

As described above, a film or the like for protecting the outer peripheral surface of the fiber bundle may be applied as the outer cover, or the outer peripheral surface of the fiber bundle may be integrally molded so as to cover it. May be. In this case, in the same manner as described above, the preheated, microwave heated, and hot air heated fiber bundles are supplied to the extruder to form the outer cover.

As described above, according to the method for producing a fiber molded product of the present invention, the fiber having a low melting point is heated from the center of the fiber bundle by microwave heating and externally molded by hot air heating, and the heat-melted fiber having a low melting point is used. Point-bonds the fibers to each other, forming a uniform network structure in the fiber bundle. When such a fiber molded product is used as an ink occlusion body, it is possible to prevent the localization of the ink (migration to the outer peripheral portion) due to the uniform mesh structure. Further, the fiber slip phenomenon due to impact is prevented, and the ink does not flow out from the outer peripheral surface.

Further, it is possible to prevent the film, the non-woven fabric, the resin molding or the like as described above from existing. In this case, similar to the method described above,
A fiber bundle having a uniform mesh structure is produced and passed through a tubular heater (super heat resistant resin) of a size to be formed. By setting the temperature of the tubular heater to be high, the surface layer can be formed with appropriate hardness and water impermeability, and this fiber molded product can be cut into a required size to obtain a product.

[0011]

【Example】

Example 1 (Production example in which a fiber molded product is wrapped with a polyester film) A. Sample 1) Special fiber sliver; Basis weight 6.8 g / m Polyester sliver (2.5 ^d , melting point 245 ° C) 70% Knitted polyester sliver (2.5 ^d , melting point 110 ° C) 30% 2) Jacket; Polyester film (width 23 mm) 3) Product specifications and dimensions; Diameter 6.6 mm φ Length 75.5 mm B. Set temperature and conditions of each section 1) Preheating device; Temperature 80 to 100 ° C. Jet hot air volume 5.0 m ³ / min 2) Microwave heating device; Output power 0.8 kW 3) Unijet heating device; Temperature 110 to 115 ℃ Jet hot air volume 5.0 m ³ / min 4) Cooling device; Temperature 10-15 ℃ Jet wind pressure 3 kg / cm ²

First, the special fiber sliver is inserted from the inlet of the preheating device. Next, the mixture is passed through the inlet inlet attachment (diameter 10 mmφ) of the microwave heating device and the outlet outlet attachment (diameter 8 mmφ) of the device. Further, it is put into the inlet of the unijet heating device (diameter 7 mmφ), passed through the molding sizing heater (6.7 mmφ) on the outlet side and passed through the cooling device. Then, in the winding machine winding tube portion, inserted together with the polyester film loaded in advance, in the winding tube portion, draw out while wrapping the rod-shaped special fiber with the film, and further press the lapping heater to perform the wrapping, It cut | disconnected to the predetermined length in the cutting part.

Example 2 (Production Example in which Fiber Molded Product is Wrapped with Polyester Nonwoven Fabric) The manufacturing method of the fiber molded product main body (fiber bundle) is almost the same as in Example 1, but the problem is that the polyester nonwoven fabric is used. Since the lapping fusion temperature is high, a hot air (temperature 200 ° C.) blowing device was attached to the front part of the lapping heater and lapping was performed.

The ink occlusion bodies obtained in Examples 1 and 2 described above were tested by the user according to the results of tests such as fusion of fibers, hardness, non-uniformity in diameter, fiber filling amount, ink absorption, retention, and ejection. It was able to meet.

Example 3 (Strip type manufacturing example in which a fiber molded product is not provided with a jacket) A. Sample 1) Special fiber sliver; Unit weight 18 g / m Polyester sliver (2.5 ^d , melting point 245 ° C) ... 70% Knitted polyester sliver (2.5 ^d , melting point 110 ° C) ... 30% 2) Jacket ... None 3 ) Product specifications and dimensions; Diameter 12 mm φ Length 100 mm B. Set temperature and conditions of each section 1) Preheating device; Temperature 80 to 100 ° C Jet hot air flow rate 5.0 m ³ / min 2) Microwave heating device; Output power 1.2 kW 3) Unijet heating device; Jet hot air flow rate 1 0 to 1.2 m ³ / min 4) Tube-shaped heat transfer heater; Diameter 12 mmφ Voltage 220 V, 350 W Set temperature 200 ° C. 5) Cooling device; Temperature 10 to 15 ° C. Jet wind pressure 3 kg / cm ² 6) Winding take-up machine ; Drawing speed 5m / min 7) Cutting part rotation speed; 50RPM

The method for producing the strip-shaped rod-shaped fiber molded product is the same as that of Example 1 in the production of the fiber molded product main body (fiber bundle), but in this case, since there is no jacket, it can be used as a unijet heating device. A tube-shaped electric heater is installed in the middle of the cooling device. Then, the rod-shaped special fibers uniformly heat-bonded to the central portion and the outer peripheral portion of the unijet heating device are passed through the same heater to further harden the outer peripheral portion (face) from the central portion to a predetermined outer diameter. It was introduced into the cooling device while being squeezed, and was then inserted into the cutting portion through the take-up machine and cut into a predetermined size.

Example 4 (Production example in which a resin molded body is integrally molded so as to cover the outer peripheral surface of a fiber molded article) A. Sample 1) Special fiber sliver; Unit weight 20 g / m Polyester sliver (2.5 ^d , melting point 245 ° C) 70% Knitted polyester sliver (2.5 ^d , melting point 110 ° C) 30% 2) Jacket; (Polyethylene) And polypropylene jacket) Resin Ultzex 3) Product specifications and dimensions; Diameter 14 mm φ Length 93 mm B. Set temperature and conditions of each section 1) Preheating device; Temperature 100 to 115 ° C. Jet hot air volume 5.0 m ³ / min 2) Microwave heating device; Attachment IN 20 mmφ, OUT 17 mmφ Output power 1.2 kW 3) Unijet heating device; Tube caliber 16mmφ Temperature 110-115 ° C Jet hot air volume 5.0m ³ / min 4) Extruder die; Die temperature 15mmφ Die temperature 170 ° C 5) Cooling water tank; Sizing 14mmφ Water tank temperature 19 ° C 6) Take-up speed; 15m / min 7 ) Cutting speed: 160RPM

Since Example 4 is to perform resin molding with an extruder, the manufacturing method of Examples 1 and 2 is
There are some differences in the manufacturing method. That is, the special fiber sliver is inserted from the preheating device of the first step, the microwave heating device of the second step is passed, and the unijet heating device of the third step is almost the same as the manufacturing process of the first embodiment. And in the extrusion section of the fourth step,
The resin (particles) put into the extrusion basic body is heated and melted by heat while being transferred by a screw, and the outer peripheral surface of the special fiber inserted into the die die is coated inside the die and passed through sizing while being compressed. Mold. Then, it was cooled and solidified in a cooling water tank, and cut into a predetermined length with a cutter through a take-up machine.

The ink occlusion bodies obtained in Examples 3 and 4 described above exhibited the following properties. The outer cover (resin) and fibers are in close contact on average. The fibers are in close contact with each other in a mesh shape, and are uniform in both the central part and the outer peripheral part. There is no difference in diameter, and hardness and the amount of fiber filled are stable. Then, as a result of tests such as fiber fusion, hardness, diameter difference, fiber filling amount, ink sucking, holding, and discharging, it was possible to meet the user's request.

[0020]

As described above, in the method for producing a fiber molded product of the present invention, since microwave heating is performed, heat is generated from the central portion of the fiber bundle, the fibers having a low melting point are melted, and the fibers are fused to each other. Put on (point adhesion). Then, since the heat treatment is performed uniformly, the network structure formed by the point adhesion described above becomes uniform. Therefore, when the fiber molded product obtained according to the present invention is used as an ink occlusion body of a marking pen, the ink flow from the pen tip body becomes stable, and the slip phenomenon due to impact does not occur. In addition, since microwave heating can heat the derivative (fiber) in a short time, the processing time is short and the productivity is good. The quality is stable. Furthermore, since microwave heating does not require heating of, for example, a heating furnace, energy efficiency is high, production management is easy, and production cost can be reduced.
In addition to the above-mentioned ink occlusion body, the present invention can easily produce a cosmetic solution occlusion body, an aromatic wick, a dental mouthpiece, a cigarette filter and various filters.

Claims (1)

[Claims] 1. A fiber bundle formed by mixing synthetic fibers having different melting points is heated from the central portion in a microwave heating step, and then the outer peripheral portion is heated in a hot air heating step to partially bond the fibers to each other. A method for producing a fiber molded article, characterized in that it is heat-sealed.