KR101268926B1 - Kapok Fiber based Nonwoven Fabric and Manufacturing Method Thereof - Google Patents

Abstract

The present invention provides a composite nonwoven fabric of kapok fibers and naturally derived biodegradable fibers.
The composite nonwoven fabric of the present invention is free from scattering due to the cutting of fibers, is excellent in shape stability, and is also excellent in sound absorption. Therefore, it can be used as a sound absorbing material of automobiles, ships, airplanes, transportation, industrial, and various industrial sound absorbing materials, and can also be used for all filling materials having form stability, such as insulation, bedding and bedding, life jackets.

Description

Kapok Fiber based Nonwoven Fabric and Manufacturing Method Thereof}

The present invention relates to a kapok fiber composite nonwoven fabric and a method for manufacturing the same, and more particularly, to a kapok fiber composite nonwoven fabric having high morphological stability and sound absorption by mixing kapok fibers with natural biodegradable fibers, and a method for manufacturing the same. will be.

Kapok fiber is a seed hair fiber of kapok tree, and its origin is Malaysia, and is mainly produced in Hawaii, Java, Philippines, Taiwan, and the like. The kapok fibers are hollow natural fibers having a fiber length of 8 to 32 mm, a thickness of 30 to 35 μm, and a circular to oval cross section. The kapok fiber is characterized by its hollow shape, has a low density of 0.30 g / cc, and is about 1/5 of the light weight of cotton (density 1.54 g / cc), and is light and elastic in addition to gloss like silk. . In addition, it is a natural fiber that has a wool-level insulation and other characteristics such as sound absorption, oil absorption, antibacterial, deodorant, far-infrared radiation, etc., and is being developed.

However, since the kapok fiber has a short fiber length and a thin cell wall and can be easily cut during carding and the like, its use is limited to furniture, bedding fillers, and life preserver fillers. In addition, efforts have been made in various ways to manufacture kapok fibers with nonwoven fabrics and utilize them as thermal insulation, sound absorption and oil absorption materials.

For example, Patent Document 1 discloses a sound absorbing material using kapok fibers. However, the sound absorbing material is only filled with the kapok fibers in a porous material without any processing.

Patent Document 2 discloses an example in which a nonwoven fabric prepared by blending a kapok fiber and a PP fiber in a 1: 1 manner is manufactured and used for removing oil. A sound absorbing material is disclosed. However, the nonwovens still cannot be seen as a complete solution to problems such as fiber cutting and scattering during the use of kapok fibers, and because there is no adhesive force between the kapok fibers, there is a problem that the shape stability of the manufactured nonwoven fabrics is poor. It's still going on.

Accordingly, the present inventors mixed and bonded a polylactic acid (PLA), which is a naturally derived fiber such as kapok, and a thermoplastic resin, polylactic acid (PLA) and kapok fibers, the scattering of chopped fiber, which is a problem of the aforementioned prior arts, It was confirmed that it can be used as an environmentally sound-absorbing material by improving the shape stability of the nonwoven fabric, and also by applying a polylactic acid in the form of hollow fiber, such as kapok, the present invention was completed to secure light weight and sound absorption.

U.S. Patent 6,338,395 Republic of Korea Patent Publication No. 2009-117136 Republic of Korea Patent Publication No. 2006-13468

An object of the present invention is to provide a nonwoven fabric having high morphological stability and sound absorption by mixing the kapok fibers with natural biodegradable fibers to form a web and then heat bonding.

Another object of the present invention is to provide a method for producing the nonwoven fabric.

The kapok fiber composite nonwoven fabric of the present invention is characterized in that the kapok fiber is adhered by a natural-derived biodegradable fiber.

The kapok fiber and the naturally derived biodegradable fiber is preferably short fibers of 1 to 10mm in length.

It is preferable that the said naturally derived biodegradable fiber is a polylactic acid fiber.

The naturally derived biodegradable fiber is preferably a hollow fiber.

The weight ratio of the kapok fiber and the naturally derived biodegradable fiber is preferably 90:10 to 10:90.

Method for producing a kapok fiber composite nonwoven fabric of the present invention comprises the steps of cutting the kapok fiber and natural derived biodegradable fibers into short fibers of 1 to 10mm; Preparing a dispersion by mixing the kapok short fibers, short fibers of a naturally derived biodegradable fiber, and a surfactant with a dispersion medium; Forming a web using the dispersion; And heat-bonding the web.

The surfactant may be one or more selected from cationic surfactants, anionic surfactants, nonionic surfactants, amphoteric surfactants.

The heat bonding may be selected from calendering, double belt press, hot air bonding, infrared bonding, ultrasonic bonding, and the like.

The kapok fiber composite nonwoven fabric of the present invention is free from scattering due to the cutting of fibers, is excellent in shape stability, and is also excellent in sound absorption. Therefore, it can be used as a sound absorbing material used in automobiles, airplanes, ships and other transports or indoor building materials.

1 is a scanning electron micrograph at 500 times the surface of the nonwoven fabric of Example 1 of the present invention,
FIG. 2 is a graph measuring changes in sound absorption coefficients of the nonwoven fabrics of Examples 1 and 2 according to frequency changes. FIG.

The nonwoven fabric of the present invention is characterized in that it is prepared by mixing the kapok fibers with polylactic acid hollow fibers.

The kapok fiber used in the nonwoven fabric of the present invention is a natural fiber obtained from the fruit of the kapok tree (Keiba pentantra, Ceiba pentantra), and its shape is hollow, low specific gravity, and has sound absorption characteristics. Also called Java fiber, the main origin of the kapok tree is Java, Sumatra, India, Thailand and the like. However, the kapok fiber used in the nonwoven fabric of the present invention may be used as it is a fiber collected in nature, preferably short fibers cut to a length of 1 ~ 10mm. If the length of the kapok fiber does not reach 1mm, the adhesion problem occurs, the strength is lowered, which is not preferable, if the length exceeds 10mm, there is a problem that the dispersion of the fiber occurs and the uniformity is lowered.

Naturally derived biodegradable fiber of the present invention is a fiber made from a polymer produced from renewable natural resources, the biodegradable fiber is decomposed into a low molecular material such as water or carbon dioxide by a natural environment such as microorganisms, light, heat, moisture, etc. Refers to a fiber made of a material that loses its initial properties. Such naturally derived biodegradable fibers include polylatic acid (PLA), polycaprolactone (PCL), polybutylene succinate (PBS), polyhydroxyalkanoate (PHA), Fibers derived from homopolymers or copolymers consisting of poly3-hydroxybutyrate (PHB), polybutylene adipate-co-nutylene terephthalate (PBAT), etc. Can be used.

On the other hand, the polylactic acid fiber is preferable in that the naturally-derived biodegradable fiber of the present invention functions as a binding material for bonding between the kapok fibers constituting the nonwoven fabric.

In addition, for sound absorption and lightness of the nonwoven fabric, the naturally-derived biodegradable fiber is preferably a hollow fiber, and more preferably polylactic acid hollow fiber having a hollow ratio of 5 to 50%.

On the other hand, the weight ratio of the kapok fiber and the naturally derived biodegradable fiber is preferably from 90:10 to 10:90. If the weight ratio of the naturally-derived biodegradable fiber does not reach 10, the binding force with the kapok fiber is lowered, which is not preferable because of the deterioration of morphological stability. If the weight ratio of the naturally-derived biodegradable fiber exceeds 90, the characteristics of the kapok fiber having natural hollow are expressed. There is a problem.

The kapok fiber and the naturally-derived biodegradable fiber length is preferably used short fibers of 1 ~ 10mm. When the length of the fibers does not reach 1mm, the problem of inter-fiber bonding occurs and the strength is not preferable. When the length of the fibers exceeds 10mm, there is a problem in that the dispersion of the fibers occurs and the uniformity is reduced.

Method for producing a kapok fiber composite nonwoven fabric of the present invention comprises the steps of cutting the kapok fiber and natural derived biodegradable fibers into short fibers of 1 to 10mm; Preparing a dispersion by mixing the kapok short fibers, short fibers of a naturally derived biodegradable fiber, and a surfactant with a dispersion medium; Forming a web using the dispersion; And heat-bonding the web.

The kapok short fibers and the polylactic acid hollow fibers in each step of the manufacturing method are as described above. On the other hand, the surfactant is used for the purpose of effectively dispersing short kapok fibers and binder fibers. Although it is possible to disperse short kapok fibers and binder fibers without adding a surfactant, the short kapok fibers and binder fibers can be dispersed quickly and effectively by adding a surfactant. Surfactants used for this purpose include cationic surfactants, anionic surfactants, nonionic surfactants and amphoteric surfactants.

Examples of cationic surfactants include alkylammoniums such as alkyltrimethylammonium or alkyltriethylammonium, alkyldimethylbenzylammonium salts, amine phosphate salts, etc., wherein alkylammoniums are represented by the formula C _n H _{2n +1} N (CH). ₃ ) ₃ X (wherein X is OH, Cl, Br, HSO ₄ or a combination of OH and Cl, n is an integer from 8 to 22) and the formula C _n H _{2n +1} N (C ₂ H ₅ ) ₃ X (wherein n is an integer of 12 to 18).

Anionic surfactants include alkyl sulfates (eg, formula C _n H _{2n +1} OSO ₃ Na (where n is 12 to 18)), alkylsulfonates (eg, C ₁₂ H ₂₅ C ₆ H ₄ SO ₃ Na), alkylcarboxylic acids (eg, C ₁₇ H ₂₅ COOH, C ₁₄ H ₂₅ COOH), and also sulfates of polyethoxylated derivatives of straight or branched chain aliphatic alcohols and carboxylic acids ; Alkylbenzenes or alkylnaphthalene sulfonates and sulfates such as sodium octylbenzenesulfonate; Alkylcarboxylates such as dodecylcarboxylate; And alkali metal and (alkyl) ammonium salts of ethoxylated and polyethoxylated alkyl and aralkyl alcohol carboxylates.

Amphoteric surfactants include alanine-based, imidazolium betaine-based, amidepropyl betaine-based, aminodipropionate and the like.

Further, nonionic surfactants include poly (ethylene oxide), (octaethylene glycol) monododecyl ether (C ₁₂ EO ₈ ), (octaethylene glycol) monohexadecyl ether (C ₁₆ EO ₈ ), and poly (alkyl Lene oxide) -poly (propylene oxide) -poly (ethylene oxide) (PEO-PPO-PEO) or inverse (PPO-PEO-PPO).

Finally, in the kapok nonwoven fabric manufacturing method of the present invention is a step of heating after the drying step. This is to help the unit kapok fibers constituting the nonwoven fabric to be bonded by the polylactic acid hollow fiber, there is no particular limitation in the method, it is sufficient as the usual heating means used in the art. Examples include calendering, double belt press, hot air bonding, infrared bonding, ultrasonic bonding, and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples. The following examples are merely illustrative of the present invention, but the content of the present invention is not limited by these examples.

Example

1. Preparation of kapok fiber / polylactic acid fiber composite nonwoven fabric

≪ Example 1 >

A kapok nonwoven fabric bonded by a polylactic acid hollow fiber was prepared by a wet-laid method.

First, the compositions used in the experiment are as follows. Kapok fibers (from Indonesia) were cut into short fibers of about 2-3 mm in size and used. Polylactic acid hollow fiber (Hubis) was used to have a fineness of 6 denier, 10% of the hollow ratio, cut into short fibers of about 2 ~ 3 mm in size. In the present invention, for improving the dispersibility of the short fibers copolymer of a nonionic surfactant of polyethylene glycol and polypropylene glycol (Sigma-Aldrich, product name Pluronic ^ⓡ 127, average molecular weight 5,800; CAS 9003-11-6) was used.

1.0 g of kapok fiber, 1.0 g of polylactic acid hollow fiber, and 0.4 g of surfactant were dispersed in 7 L of water in a mixing bath, followed by stirring at 500 rpm for 5 minutes to prepare a dispersion for forming a web.

The dispersion liquid for web formation was thrown into the paper machine, it stirred, water was removed, the web was formed, and it naturally dried for 24 hours or more. At this time, the wire screen of the paper machine used the screen mesh of 120 #.

Finally, the web was bonded in a belt-laminating process (temperature between rollers at a temperature of 195 ° C. and a roller speed of 1.0 m / min to prepare a nonwoven fabric. The weight of the produced nonwoven fabric was 88 g / m ² ).

<Example 2>

Example 2 was prepared in the same manner as in Example 1, except that 1.4 g of kapok fibers and 0.6 g of polylactic acid hollow fibers were used.

2. SEM evaluation

1) Evaluation method

In order to observe the surface of the kapok / polylactic acid composite nonwoven fabric prepared from the example was observed by magnification 500 times using a differential scanning electron microscope (JEOL, JSM-5510).

2) Evaluation result

1 is a scanning electron micrograph at 500 times the surface of the nonwoven fabric made in Example 1 of the present invention.

As shown in the differential scanning electron micrograph, it can be seen that the surface of the polylactic acid hollow fiber is melted by heat and adhered to the kapok fiber, which indicates that the nonwoven fabric produced may have morphological stability.

3. Sound absorption evaluation

1) Evaluation method

Sound absorption evaluation is measured in the range of 400 ~ 5,000 Hz using a sound absorption tester (01dB-Metravib), the experiment is in accordance with the KS F 2814 standard.

2) Evaluation result

FIG. 2 is a result of measuring a change in a sound absorption coefficient of a nonwoven fabric of Examples 1 to 2 according to a change in frequency. 2, 1K, 2K, 3.15K and 5K are sound absorption coefficients measured at 1000, 2000, 3150 and 5000 Hz, respectively. Referring to FIG. 2, the kapok / polylactic acid composite nonwoven fabric showed a tendency to increase the sound absorption characteristics with increasing frequency, and Example 2, which has a larger kapok content than Example 1, exhibited higher sound absorption characteristics. I could confirm it.

The kapok fiber composite nonwoven fabric of the present invention can be used as all filling materials having form stability, such as sound absorbing materials for automobiles, ships, airplanes, etc., sound absorbing materials for building and various industrial purposes, oil absorbing fabrics, separators, insulation, bedding and bedding, life jackets, etc. have.

Claims (10)

delete delete delete delete delete Cutting kapok fibers and polylactic acid hollow fibers, which are naturally derived biodegradable fibers, into short fibers of 1 to 10 mm;
Preparing a dispersion by mixing the kapok short fibers, short fibers of a naturally derived biodegradable fiber, and a surfactant with a dispersion medium;
Forming a web using the dispersion; And
Method for producing a sound absorbing kapok fiber composite nonwoven fabric comprising the; step of heat-bonding the web. delete delete The method of claim 6, wherein the surfactant is at least one selected from cationic surfactants, anionic surfactants, nonionic surfactants and amphoteric surfactants. The method of claim 6, wherein the heat bonding is calendering, double belt press, hot air bonding, infrared bonding or ultrasonic bonding.

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