KR20030058976A - High electronic fiber contained filter and manufacturing method of same - Google Patents

Abstract

PURPOSE: Provided are a high dielectric constant electrostatic filter and a method for manufacturing the same, the filter having high filtration ability and electrostatic force. CONSTITUTION: The method comprises the steps of fabricating fibers by spinning using blend of polypropylene (PP) of 80-99 wt% and polyvinylidene fluoride (PVDF) of 1-20 wt%; polarizing the fibers so as for the fibers to have high dielectric constant; cutting the polarized fibers and making staple fibers; making strings using the fibers; weaving a cloth using the strings; and treating the cloth with plasma, corona discharging or ion beams.

Description

High dielectric constant electrostatic filter and its manufacturing method {High electronic fiber contained filter and manufacturing method of same}

The present invention relates to a high dielectric constant electrostatic filter and a manufacturing method thereof, and more particularly, to an electrostatic filter manufactured using a high dielectric constant woven fabric and a manufacturing method thereof.

Conventional electrostatic fibers are manufactured using microfiber, and the electrostatic woven fabric is post-processed with wax for effective dust collection. The electrostatic woven fabric is made of an electrostatic filter for the purpose of filtering fine particles of dust and ionic materials. However, the static charge retention period of the filter is very short, which makes it impractical and the post-processed wax is washed off, which greatly reduces the dust collection efficiency.

In addition, the electrostatic filter is usually manufactured using a non-woven fabric. Unlike nonwovens, wovens are woven through yarns processed into fibers. The woven fabric can form fine pores in the woven fabric by controlling the density or structure of the fiber during spinning or weaving in a conventional manner. Therefore, a woven fabric containing a certain micropores is applied as a filter for filtration of dust to remove dust from the air by allowing the air to pass through the fine pores between the fibers in the woven fabric to prevent the transmission of dust, such as dust.

The filter should be considered first. In particular, conventional filters and dust masks mainly rely on mechanical filtering. Recently, many researches have been conducted on the electrostatic filter for the purpose of filtering fine particles of dust and ionic materials, but there is a problem that the electrostatic retention period of the filter is very short, which is not practical.

For the purpose of improving electrostatic retention, U. S. Patent No. 5,645, 627 used a method of injecting electric charges into fibers made of polymers comprising polypropylene, polyethylene, polyester, polyamide, polyvinyl chloride and polymethyl methacrylate. A satisfactory improvement in electrostatic retention has not been achieved.

Therefore, there is still a need for the development of an electrostatic filter having excellent filtration ability and excellent electrostatic retention.

Electrostatic fibers used in electrostatic filters can also be applied to the manufacture of electrostatic sweepers, which are cleaning tools. In particular, it is recommended that the electrostatic mop is charged with static electricity to clean the fine materials such as dust of computer or TV CRT. However, currently marketed electrostatic mop has a problem of low dielectric constant or short static retention period, there was a problem that the collection rate of dust significantly reduced when reuse after washing the electrostatic mop once. Accordingly, there is still a need for an electrostatic mop having a high dielectric constant, a good static electricity retention, and a small reduction in dust collection performance even after reuse after washing.

Accordingly, an object of the present invention is to provide a high dielectric constant electrostatic filter capable of maintaining a function as a filter for a long time because of excellent filtration ability to fine particles of dust and ionic materials and high electrostatic retention.

In addition, an object of the present invention is to provide a high-k dielectric mop that can remove fine dust.

In order to achieve the above object, the present invention provides a fiber manufacturing step of producing a fiber by (a) mixed spinning of polyvinylidene fluoride (PVDF) and polypropylene (PP: polypropylene), (b) the fiber Polarization treatment step of improving the dielectric constant by polarizing the fiber produced in the manufacturing step, (c) a short fiber manufacturing step of producing a staple fiber by cutting the fiber with improved dielectric constant in the polarization treatment step; (D) a yarn manufacturing step of spinning the yarn using the staple fibers prepared in the short fiber manufacturing step; And (e) provides a high dielectric constant electrostatic filter comprising a woven fabric manufactured by a method comprising a weaving step of making a woven fabric using the yarn prepared in the yarn manufacturing step.

Hereinafter, the present invention will be described in detail.

The inventors of the present invention have been researching to produce a woven fabric having excellent static electricity retention, and fabricated fibers using polyvinylidene fluoride (PVDF) and polypropylene (PP; Polypropylene) having excellent piezoelectric properties as a fiber material. When using a woven fabric produced as an electrostatic filter or electrostatic rag was found to have a significantly improved electrostatic retention compared to the conventional case has been completed the present invention.

First, the high dielectric constant woven fabric manufacturing method of the present invention (a) a fiber manufacturing step of producing a fiber by mixing the polyvinylidene fluoride (PVDF: poly vinylidene fluoride) and polypropylene (PP: polypropylene), (b) Polarization treatment step of improving the dielectric constant by polarizing the fiber produced in the fiber manufacturing step, (c) short fiber manufacturing step of producing a staple fiber by cutting the fiber with improved dielectric constant in the polarization treatment step; (D) a yarn manufacturing step of spinning the yarn using the staple fibers prepared in the short fiber manufacturing step; And (e) characterized in that it comprises a weaving step of making a woven fabric using the yarn prepared in the yarn manufacturing step.

In the fiber manufacturing step, the fiber of filament is manufactured by mixing and spinning polyvinylidene fluoride and polypropylene. The fiber manufacturing method of the present invention is preferably a wet spinning method, a dry spinning method, a melt spinning method, and most preferably a melt spinning method.

Herein, the content of polyvinylidene fluoride is preferably 1 to 20% by weight, and the content of polypropylene is 99 to 80% by weight. As the polyvinylidene fluoride content is increased in the range of 1 to 20% by weight of polyvinylidene fluoride, the filtration efficiency of the electrostatic filter is gradually increased, and when the content reaches the optimum value of 10% by weight, the filtration efficiency of the electrostatic filter is It reaches almost 100%.

The diameter of the fibers to be produced is preferably 5 to 20 μm, preferably 10 to 15 μm. As the diameter of the fiber increases, the filtration efficiency of the electrostatic filter decreases, and the filtration efficiency of the electrostatic filter is high at a thickness within the above range.

In the polarization treatment step, a high dielectric constant electrostatic fiber is produced from the fibers produced in the fiber manufacturing step. The stretching is by polarization to improve the dielectric constant of the fiber. Polyvinylidene fluoride has an alpha form and a beta form, and the thing with high electric charge is a beta form. In this step, the α form of the polyvinylidene fluoride contained in the fiber is changed to the β form, resulting in high chargeability.

The polarization treatment repeats winding / unwinding / rewinding the fibers and scans the electron beams sequentially so as to polarize the intramolecular electron distribution of the high dielectric constant fibers constituting the woven fabric by the impact of the high-charged electron beam at the scanned portion. Polarization). This can be easily understood by those skilled in the art.

In the short fiber manufacturing step, the high dielectric constant fibers are processed into staple fibers. Staple fiber is made by cutting the filament to an appropriate length in order to make the yarn of the properties that can not be expected in filament yarn, the staple fiber of the present invention is preferably 30 mm to 60 mm in length.

In the yarn manufacturing step, the staple fibers are processed to release the fibers by rollers, and then the yarns are manufactured. Staple fibers with short lengths of fibers are fed in a disordered array of fibers, so that these fibers are well opened and spun. The manufacturing method consists of open and mixed cotton, face and face noodles, soft, rough and square. The yarn manufacturing step is carried out by conventional techniques well known to those skilled in the art. The number of yarns of the present invention is preferably 5 to 20, and the strength of the twist is represented by the number of twists, and it is preferable to give 5 to 20 twists between 1 inch (2.54 cm) in length.

In the weaving step, the woven fabric is manufactured from the yarn produced in the yarn manufacturing step. The yarn may be mixed alone or with other common fibers to produce a woven fabric according to a conventional woven fabric manufacturing method, and in particular a woven fabric having a structure suitable for use for filters can be obtained. A woven fabric is made by a normal woven fabric manufacturing method in a continuous plane of a certain length having a certain width, length and thickness by combining the warp yarn and the weft yarn at right angles. In addition, in the present invention, when mixing the other general fibers in the yarn, the mixing ratio of the other general fibers is preferably polarized to use less than 200 parts by weight of the normal fiber to 100 parts by weight of the yarn. When the amount of the normal fibers exceeds 200 parts by weight, it is not preferable that the static electricity holding power of the fabric to be produced is low.

The density of the yarn in the woven fabric manufacturing step is not particularly limited, but considering the filtration capacity and economical efficiency of the electrostatic filter, the appropriate density is specified below. The density of the woven fabric is the number of rhythms of warp or weft yarn within a section of the woven fabric, specifically the number of chops of weft or warp yarn within 2.54 cm (inch). The woven fabric density of the present invention is preferably 5 to 20 weft yarns or warp yarns, more preferably 10 to 15 yarns.

In addition, the method for manufacturing a high dielectric constant woven fabric of the present invention may further include a treatment step selected from the group consisting of plasma treatment, corona discharge, and ion beam treatment of the woven fabric produced in the woven fabric manufacturing step after the woven fabric manufacturing step. The plasma treatment is preferably carried out in a conventional method at 100 KW, 0.1 Torr in an oxygen atmosphere. In addition, after the fabric manufacturing step, the corona discharge or ion beam treatment, which can be further performed on the fabric manufactured in the fabric manufacturing step, is performed by a conventional method. Such plasma treatment, corona discharge, or ion beam treatment may increase the electrostatic force by 20 to 50% relative to the same weight of the fiber.

In addition, the present invention provides a high-k dielectric woven fabric produced by the above method, the high-k dielectric woven fabric produced by the present invention is characterized by high electrostatic force, the static retention period is maintained for a long time.

The present invention also provides a high dielectric constant electrostatic filter made of the woven fabric. As a method of manufacturing the high dielectric constant electrostatic filter, filter manufacturing methods for manufacturing a filter using a woven fabric are generally applied, and the high dielectric constant electrostatic filter of the present invention is particularly preferably applied as an electrostatic filter to a dust mask, an air filter or a vacuum cleaner. Do. The high dielectric constant electrostatic filter of the present invention has an excellent electrostatic force and shows a significantly improved filtration efficiency compared to the conventional filter for the filtration of ionic materials and fine dust, and the electrostatic force is long when the conventional electrostatic filter is used several times because of the long static retention period. There was a problem that falls significantly compared to this initial, but the electrostatic filter of the present invention is maintained at a level similar to the initial level even after using several dozen times.

The present invention also provides a high dielectric constant electrostatic mop manufactured by the high dielectric constant woven fabric. The high dielectric constant electrostatic mop is manufactured through a conventional method such as cutting the woven fabric into an appropriate size. The high dielectric constant electrostatic mop of the present invention has a high electrostatic force, has excellent cleaning efficiency, has a long electrostatic retention period, and has a markedly improved lifespan compared to a conventional electrostatic mop. The capture performance is almost the same as early days.

Hereinafter, preferred examples are provided to aid in understanding the present invention. However, the following examples are provided only to more easily understand the present invention, and the present invention is not limited to the following examples.

Example 1

Fibers were prepared by mixing and spinning 10% by weight of polyvinylidene fluoride and 90% by weight of polypropylene, and the fibers were polarized and then cut into staple fibers of 58 mu m. Using the staple fiber with improved dielectric constant, high-k dielectric woven fabric was manufactured by a conventional woven fabric weaving method while spinning 10 times, 15 twisted yarns per inch, and adjusting the density to have 10 weft yarns per inch.

Example 2

Plasma treatment of the woven fabric of Example 1 was performed at 100 KW and 0.1 torr in an oxygen atmosphere to prepare a high dielectric constant woven fabric.

Comparative Example 1

Fibers were prepared using only polypropylene, woven fabrics were made from the fibers, and the same method as in Example 1 was used for the polarization treatment and the woven fabric manufacturing method.

Experimental Example 1

In order to test the filtration capacity of the ionic material of the high dielectric constant woven fabric prepared according to the present invention, the filtration test was carried out according to the NaCl aerosol test method.

The NaCl aerosol test method pressurizes and warms up a 1% sodium chloride (NaCl) solution, disperses it in the air in the form of an aerosol having a particle size of about 0.3 μm, and then passes the filter to be tested at a flow rate of 34 L / min. The filtration rate was expressed as a percentage (%) by measuring the amount of sodium chloride remaining in the air after passage. In this experiment, the filtration rate of the woven fabrics of Examples 1 and 2 and Comparative Example 1 was measured. As a result of the experiment, the filtration rate of the woven fabric of Example 1 according to the present invention was 99.0%, and the woven fabric of Example 2 had a filtration performance of almost 9% of the filtration rate of the woven fabric of Comparative Example 1, and almost 0% of the woven fabric of Comparative Example 1. Could not be seen. The results of the experiment shows that the woven fabric according to the present invention has a very good filtration efficiency for the ionic material, it can be seen that the filtration performance is more excellent when plasma treatment.

Experimental Example 2

In order to observe the performance when the woven fabric prepared in Example 1 was used as an electrostatic mop, the dust of the computer monitor was wiped with Example 1 and Comparative Example 1. The woven fabric of Example 1 according to the present invention was wiped much better than the woven fabric of Comparative Example 1. In addition, after one use, the woven fabrics of Example 1 and Comparative Example 1 were washed with water and dried to find out whether they can be reused as electrostatic mops. The woven fabric of Example 1 according to the present invention was well wiped off the dust of the computer monitor to the same extent as when used for the first time, but the woven fabric of Comparative Example 1 showed that the dust collecting performance was remarkably degraded when reused. The results of this experiment show that when the woven fabric according to the present invention is used as an electrostatic mop, the dust collection performance is superior to that of the conventional electrostatic mop, and the life is maintained at the initial level even when reused after washing, so that the service life is longer than that of the conventional electrostatic mop. Significantly improved.

As described above, the high dielectric constant woven fabric produced by the present invention has a high electrostatic retention capability compared to the conventional woven fabric, so that the high dielectric constant electrostatic filter manufactured by the woven fabric has a higher filtration efficiency for ionic materials than the conventional filter. It is remarkably excellent, and it can be seen that the function as a filter lasts a long time. In addition, the high-k electrostatic mop using the woven fabric of the present invention has an excellent electrostatic retention power, excellent cleaning function, and has the advantage of significantly extending the service life.

Claims (5)

(a) a fiber manufacturing step of producing a fiber by mixing and spinning polyvinylidene fluoride (PVDF: poly vinylidene fluoride) and polypropylene (PP: polypropylene); (b) polarization treatment step of improving the dielectric constant by polarizing the fiber produced in the fiber manufacturing step; (c) a short fiber manufacturing step of preparing staple fibers by cutting fibers having improved dielectric constant in the polarization treatment step; (D) yarn manufacturing step of spinning the yarn using the staple fibers prepared in the short fiber manufacturing step; And (e) weaving step of making a woven fabric using the yarn produced in the yarn manufacturing step; High dielectric constant electrostatic filter comprising a woven fabric produced by the method comprising a. The high dielectric constant electrostatic filter according to claim 1, wherein the polyvinylidene fluoride is contained in an amount of 1 to 20 wt% and the polypropylene is 80 to 99 wt%. The high dielectric constant electrostatic filter according to claim 1, wherein the fiber prepared in step (a) has a diameter of 5 to 20 µm. The high dielectric constant electrostatic filter according to claim 1, wherein the density of the woven fabric manufactured in step (e) is 5 to 20 weft yarns or warp yarns within 2.54 cm. The high dielectric constant electrostatic filter of claim 1, wherein the woven fabric is further treated after the step (e) by a method selected from the group consisting of plasma treatment, corona discharge, and ion beam treatment.