KR19990079310A - Long fiber nonwoven fabric with excellent durability and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a long fiber nonwoven fabric having excellent durability and a method for producing the same.

The present invention essentially includes the following process in producing a long fiber nonwoven fabric.

- next -

[i] the core (A) is polyethylene and the core (B) is polyester

Or spinning polycarbaceous complex fiber which is polypropylene,

[ii] passing the spun sheath fiber into a heating vessel,

[iii] optionally, stretching the myocardial composite fiber with an air ejector,

[iv] The hot components are fused to each other in the nonwoven fabric by hot air.

The long fiber nonwoven fabric of the present invention has a pore size of 90 to 120 μm and a permeability coefficient of 3.0 to 5.0 ×. 10 ^-3 cm / sec, mainly used for civil engineering materials.

Description

Long fiber nonwoven fabric with excellent durability and manufacturing method thereof

The present invention relates to a long fiber nonwoven fabric having excellent durability and a method for producing the same.

Long-fiber nonwoven fabrics have superior mechanical properties, morphological stability, and thermal stability compared to short-fiber nonwoven fabrics. In recent years, long-fiber nonwoven fabrics have been widely used in various fields such as automotive filters, building air conditioning bag filters, building roofing papers, and civil engineering nonwoven fabrics. It is widely used as an industrial material.

In particular, long-fiber nonwoven fabric is used as a civil engineering material, such as ground reinforcement and ordered material because it has a unique high strength.

Long fiber nonwoven fabric used as civil engineering material should be very strong as well as durable against acid, alkali or water so that it can function semi-permanently once it is installed due to the nature of its use.

In general, long-fiber nonwoven fabric is prepared by the process as shown in FIG.

That is, the long fiber nonwoven fabric spins [iii] thermoplastic resin through the spinneret (1), [ii] cools the spun multifilament yarn (Y) with the quenching chamber (2), and [iii] the air eject (5). Stretched with compressed air in the air, and dispersed the multifilament in the [6] carding machine (6), and then randomly laminated on the [6] net conveyor (8) to produce a nonwoven web, and [9] a calender roll (9). It is manufactured by crimping with), entangled the fibers with needle punching and winding up.

Until now, long-fiber nonwoven fabrics have been mainly made of polyester or polypropylene resin having excellent chemical stability to impart durability, but polypropylene is weak to acid, and polyester is weak to alkali and decomposes.

In particular, since polyester is well hydrolyzed, it is easily removed when used as a civil engineering material.

Although a method for producing a nonwoven fabric from para- or meta-based aromatic polyamide fibers (aramid fibers) for producing a long-fiber nonwoven fabric having excellent durability is also known, there is a problem in that the aramid fibers themselves are expensive and inexpensive.

Also known is a method of coating acrylic resin on long-fiber nonwoven fabric made of polyester or polypropylene to impart water resistance and chemical resistance.However, when used as a civil nonwoven fabric, it is subject to continuous friction with soil and contact with effluent. Therefore, the effect is insignificant, and there is a problem that the outflow water of the soil layer is contaminated by the corrosion of the coated acrylic resin.

Therefore, there has been a demand for a technology development capable of imparting excellent durability against acids, alkalis, and moisture to the long fiber nonwoven fabric so as to be suitable for applications such as civil nonwoven fabrics.

On the other hand, as a method of improving the strength of the long-fiber nonwoven fabric in the weaving process, it is most widely used to increase the pressure of the compressed air supplied to the compressed air supply device 4 and to draw at a high draw ratio in the air eject 5.

However, the pressure of the compressed air can only be raised to a certain level, and this method does not fundamentally improve the strength of the long fiber nonwoven fabric.

If the pressure of the compressed air is raised above a certain limit, the filament is cut or, in the case of a composite fiber, peeling between components occurs. It is also uneconomical to increase air consumption during stretching.

In Japanese Patent Laid-Open No. 6-264347 and Korean Patent Application No. 97-323515, a method of heat-treating a polymer spun before stretching is provided by installing a heating tube 3 between a spinneret 1 and an air ejector 4 under specific conditions. Suggesting.

However, it is very important for these methods to set the heating vessel position, length, inner diameter and temperature to suit the type of yarn to be spun.

Therefore, the kind of fibers constituting the long fiber nonwoven fabric is different from that of the cited patent.

In this case, the conditions for the installation of the heater should be newly studied.

On the other hand, the prior art of intertwining the fibers of the nonwoven web by the needle punching method also has a problem that the production speed is limited due to the vertical movement of the needle.

The present invention is to provide a method for producing a long-fiber nonwoven fabric having excellent durability against moisture, acid, and alkali with high productivity.

1 is a schematic view of a manufacturing process of a conventional long fiber nonwoven fabric.

2 is a manufacturing process schematic diagram of the present invention.

3 is a cross-sectional view of the present invention composite fiber.

※ Explanation of main parts in drawings

1: spinneret 2: quenching chamber

3: heating tube 4: compressed air supply device

5: Air eject 6: Opening device

7: air suction device 8: net conveyor

9: calender roll 10: dry heat treatment machine

11: winder 12: needle punching machine

A: Sheath B: Core

Y: multifilament thread

The present invention relates to a long fiber nonwoven fabric having excellent durability and a method for producing the same.

More specifically, the present invention relates to a method for producing a long-fiber nonwoven fabric having excellent durability, characterized in that the following steps are essential in producing the long-fiber nonwoven fabric.

- next -

[i] the core (A) is polyethylene and the core (B) is polyester

Or spinning polycarbaceous complex fiber which is polypropylene,

[ii] passing the spun sheath fiber into a heating vessel,

[iii] optionally, stretching the myocardial composite fiber with an air ejector,

[iv] The hot components are fused to each other in the nonwoven fabric by hot air.

In addition, the present invention is composed of a sheath-type composite fiber in which the first portion (A) is polyethylene and the core portion (B) is polyester or polypropylene, the pore size is 90 to 120 μm, and the permeability coefficient is 3.0 to 5.0 ×. 10 ^-3 It relates to a long fiber nonwoven fabric having excellent durability that is cm / sec.

The present invention is characterized in that the use of a sheath-type composite fiber in which the ultra-addition polyethylene and the core is polyester or polypropylene for the durability and strength improvement when manufacturing the long fiber nonwoven fabric.

In another aspect, the present invention is characterized in that the heating tube is installed under a certain condition between the detention and the air ejection, and the fibers in the nonwoven web are entangled with each other by a heat fusion method.

Hereinafter, the present invention will be described in detail with reference to the drawings.

Figure 2 is a process schematic diagram of the present invention, Figure 3 is a cross-sectional view of the composite fiber of the present invention.

First, in the spinning process, the composite yarn is manufactured by spinning the spinneret 1 so that polyethylene is located at the core portion A and polyester or polypropylene is placed at the core portion B.

In the present invention, a polyethylene resin having a low cost, excellent durability against alkali and acid, and no hydrolyzability is used as the component (A) to improve durability of the long fiber nonwoven fabric.

In addition, in the present invention, polyester or polypropylene having high strength

The resin is used as the core (B) component to compensate for the weakness of the weak polyethylene resin.

In addition, the reason for arranging polyethylene on the surface of the fiber (Sheath) is to dissolve the fiber surfaces easily even at a low heat treatment temperature in the subsequent heat treatment process, so that the fibers are easily thermally bonded to each other, and the polyester or polypropylene is arranged inside the fiber. The reason is to prevent the deformation of the fiber shape or the deterioration of physical properties such as strength by the heat treatment temperature.

It is important that the weight ratio of the polymer constituting the sheath portion (A) and the (B) constituting the core portion is 60:40 to 10:90 during the composite fiber spinning.

That is, it is preferable to use 10 to 60 weight% of polyethylene, and 40 to 90 weight% of polyester or polypropylene. In consideration of workability and the like, it is more preferable to use 20 to 50% by weight of polyethylene and 50 to 80% by weight of polyester or polypropylene. If the polyethylene is less than 10% by weight, the delamination between the polymers during the spinning process is severe and the strength of the fiber fusion point decreases during the heat treatment. In addition, when polyethylene exceeds 60 weight%, the strength of a fiber falls.

In addition, the single yarn fineness (monofilament denier) of the composite fiber during composite spinning is preferably 5 to 20 denier, more preferably 8 to 5 denier in consideration of strength and drainage.

If the single yarn fineness is less than 5 denier, there are less voids in the nonwoven fabric, which reduces the filter function, drainage and ground reinforcement. If the single yarn fineness exceeds 20 denier, the nonwoven fabric becomes bulky more than necessary, making handling and transportation inconvenient. Done.

Next, the multi-filament yarn (Y) composite spun as described above is cooled and solidified by the quenching chamber (2), passed through the heating tube (3), and stretched in the air eject (5) using compressed air.

The present invention is characterized in that the heating cylinder (3) is installed between the spinneret (1) and the compressed air supply device (4) to heat-treat the cooled solidified yarn (Y) before stretching.

The present invention can reduce the consumption of compressed air at the time of stretching by installing the heating cylinder (3), and can improve the crystallinity and orientation of the fiber by efficient stretching.

As a result, cutting and peeling of the filament can be reduced as compared with the conventional method of increasing the pressure of compressed air for efficient stretching.

The installation position, length, internal diameter and temperature of the heating tube 3 determine the fiber properties.

It is an important factor.

The heating cylinder 3 must be installed at a position on the spin line where the multifilament thread Y is completely cooled and solidified.

If the multifilament is not completely solidified into the heating tube (3), the filaments collide with each other and they are fused or cut.

In general, the heating cylinder 3 is preferably installed at a distance of 60 to 100 cm from the spinneret 1.

The effect of heat treatment is theoretically good for a long time at low temperature. However, since the installation area is limited, the effect of heat treatment is determined in association with the heat treatment temperature. The length of the heating tube is 30 ~ 150㎝, and the narrow installation area increases the heat treatment temperature and shortens the length. If there is room in the installation area, the heat treatment temperature is decreased and the length is increased. According to the test in the present invention, the length of the heating tube 3 is preferably 60 to 120 cm, and the heat treatment temperature varies slightly depending on the core layer material in the fiber, but 100 to 180 ° C. is appropriate. More preferably, it is 110-160 degreeC level.

However, the heat treatment temperature and the heat treatment length are also affected by the inner diameter of the heating tube 3 through which the multifilament yarn Y actually passes. The inner diameter is 10 to 60 mm, and more preferably 20 to 50. Mm.

The filament (Y) heated above the glass transition temperature (Tg) in the heating tube 3 is air by the high pressure air supplied from the high pressure air supply device 4 directly connected to the lower end of the heating tube (3) Guided to the ejector 5, stretching is performed.

The filament passed through the heating tube 3 in the present invention is much stretched even under air pressure or lower pressure as used in the conventional manufacturing process, thereby increasing the crystallinity and orientation of the produced filament. That is, the birefringence of the filaments produced by spinning the polyester by the conventional method is 0.6 to 1.0 × 10 ^-3 On the contrary, the birefringence of the fibers produced by the present invention was 1.2 ×. 10 ^-3 Increase over. In addition, the strength of the filament is also increased so that the strength of the monofilament collected on the net conveyor (8) stays at the level of 3-4g / d is improved to 4.5g / d or more when using the heating tube 3 of the present invention Peel strength is over 3,000 times.

Subsequently, the stretched composite fiber is dispersed by the carding machine 6 and then randomly laminated on the net conveyor 8 to produce a nonwoven web, which is pressed with a calender roll 9 under a constant temperature and pressure.

The pressing process by the calender roll 9 may be omitted depending on the use of the product.

Next, the nonwoven web compressed in the calender roll 9 is thermally fused at the same time as the drying in the dry heat treatment machine 10 and then wound in the winder 11 to produce a long fiber nonwoven fabric.

The dry heat treatment unit 13 is heated only to a temperature at which the polyethylene polymer constituting the initial portion (surface) of the composite fiber can be melted.

If the temperature of the dry heat treatment machine 13 is too high, the yarns constituting the core of the composite fiber may also melt, and the physical properties of the nonwoven fabric may be degraded. If the temperature is too low, thermal fusion of the fiber surface may not occur easily. .

The surface of the composite fibers constituting the nonwoven web by the heat treatment is partially heat-sealed with each other, the strength of the nonwoven fabric is further improved because the inside of the fiber maintains the fiber shape as it is.

In addition, the fibers in the nonwoven web are not physically entangled with each other, but the bulkiness of the nonwoven is excellent because only the fiber surface is heat-sealed and the original shape of the nonwoven web is maintained.

The present invention does not require the vertical movement of the needle compared to the method of imparting entanglement by the conventional needle punching, the production speed of the nonwoven fabric is improved by more than two times.

In addition, there is no fiber damage due to needle punching, so no dust is generated.

The quality of the nonwoven fabric is improved.

The long fiber nonwoven fabric of the present invention has a pore size of 90 to 120 μm and a permeability coefficient of 3.0 to 5.0 ×. 10 ^-3 cm / sec.

In the present invention, the pore size and permeability coefficient of the nonwoven fabric and the peel strength of the composite fiber are measured as follows.

ㆍ pore size (μm)

It is measured by ASTM D 4751-93 method.

Permeability coefficient (cm / sec)

It is measured by ASTM K 4491-89 method.

ㆍ Birefringence ( ▵n )

Attach a berac compensator to the polarization microscope and measure the retardation (delay time) obtained from the interference chromaticity of the sample.

▵n =

Peel Strength

After the two yarns are twisted (crossed) with 2.5 twists to give an angle of 45 ° to the intersecting parts by using the Safri friction force tester of TONGYANG CORPORATION, the tension is 0.2g / d and friction per minute Under conditions of 100, these yarns can be

Right) by 1 cm repeatedly to impart friction between the yarns,

The total number of frictions until the cuts are measured. The measured total friction coefficient until cutting indicates peel strength.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited only to the following examples.

Example 1

After melting polyethylene and polyester at a weight ratio of 20:80, they were spun at 280 ° C. so that the polyethylene was located at the beginning and the polyester was located at the core. Cooled and solidified with a chamber, they were passed through a 100 ° C. heating tube (length: 80 cm, internal diameter: 50 mm) installed 80 cm below the spinneret, and compressed air having a pressure of 1.5 kg / cm 2. A nonwoven web is produced by stretching on an air eject and integrating on a net conveyor with a speed of 50 m / bone.

The nonwoven web is compressed with a calender roll at 120 ° C., dried and heat-sealed in a dry heat treatment machine at 125 ° C., and wound to prepare a long fiber nonwoven fabric.

The results of measuring the physical properties of the prepared myocardial composite fiber and long fiber nonwoven fabric are shown in Table 2.

Example 2-Example 4 and Comparative Example 1

Polymer type, weight ratio and single yarn fineness, location of heating tube,

A long fiber nonwoven fabric was manufactured in the same process and conditions as in Example 1 except that the length, the internal diameter and the temperature, the pressure of the compressed air, the temperature of the calender roll, and the dry heat treatment machine were changed as shown in Table 1. The results of measuring the physical properties of the prepared myocardial composite fiber and long fiber nonwoven fabric are shown in Table 2.

<Table 1> Manufacturing Conditions

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Composite fiber Polymer Type (Ultra Component / Core Component) PE / PET PE / PET PE / PET PE / PP PE / PET Weight ratio (super ingredient / core ingredient) 20/80 50/50 60/40 30/70 50/50 Single yarn fine island (denier) 10 15 5 10 Welding Heater Distance to Detention (cm) 80 100 70 120 40 Length (cm) 80 100 120 150 20 Internal diameter (mm) 50 40 60 10 40 Temperature (℃) 100 120 150 180 120 Compressed Air Pressure (㎏ / ㎠) 1.5 1.5 1.5 1.5 1.5 Calender roll temperature (℃) 120 120 120 120 - Dry Heat Treatment Temperature (℃) 125 125 130 130 -

In Table 1, PE represents polyethylene, PET represents polyester, and PP represents polypropylene.

<Table 2> Measurement results

According to the present invention, since the long fiber nonwoven fabric is made of a sheath type composite fiber in which polyethylene having excellent durability against moisture, acid, and alkali is located at the beginning, and polyester having excellent strength is located at the core, the long fiber nonwoven fabric has high durability and strength. Can be improved.

In addition, the present invention is an efficient stretching is possible because the heating tube is installed between the detention and the air eject. As a result, the strength of the long fiber nonwoven fabric can be improved.

In addition, the present invention can improve the bulkiness and productivity because the heat fusion method is used instead of needle punching when jamming.

Claims (5)

In manufacturing a long fiber nonwoven fabric, a method for producing a long fiber nonwoven fabric having excellent durability, comprising the following steps. - next - [i] the core (A) is polyethylene and the core (B) is polyester Or spinning polycarbaceous complex fiber which is polypropylene, [ii] passing the spun sheath fiber into a heating vessel, [iii] optionally, stretching the myocardial composite fiber with an air ejector, [iv] The hot components are fused to each other in the nonwoven fabric by hot air. The method for producing a long fiber nonwoven fabric having excellent durability according to claim 1, wherein the position, length, inner diameter, and temperature of the heating vessel satisfy the following conditions. -Below- Heater location: 60-100cm from the lower part of detention Heating tube length: 30-150 cm Heater inner diameter: 10 ~ 60mm Heater temperature: 100 ~ 180 ℃ The core part (A) is made of polyethylene, and the core part (B) is made of a composite material of the sheath type having a polyester or polypropylene, the pore size is 90 to 120 μm, and the coefficient of permeability is 3.0 to 5.0 ×. 10 ^-3 Long fiber nonwoven fabric with excellent durability that is cm / sec. The birefringence of the cardiac herbaceous fiber is 1.2 × 10 ^-3 The long fiber nonwoven fabric excellent in the durability which is more than the above and whose strength is 4.5 g / d or more. The method for producing a long-fiber nonwoven fabric having excellent durability according to claim 3, wherein the peel strength of the core sheath composite fiber is 3,000 times or more.