WASHING-ENDURING HIGH DENSITY MICRO-FIBER FABRIC
FIELD OF THE INVENTION
The present invention relates to a washing-enduring and high-density micro-fiber fabric, and more particularly, to a washing-enduring and high density micro-fiber fabric which has the average pore size of 4.0 μm or less after washing
5 or more times, and prevents undesirable microorganisms and minute particulates derived therefrom from being penetrated through the fabric.
BACKGROUNDS OF THE INVENTION
The modernization of living environments achieved after the Industrial Revolution have provided much convenience for human being, but have induced the serious environmental problems as a side effect thereof. Also, the living conditions of various microorganisms existing around the human being have been greatly changed. Therefore, microorganisms, which have a tolerance to the conventional insecticides, have been recently appeared. In addition, with the wide-spread use of an apartment as a housing, residences of the human being are densely concentrated, and the living of the human being is mainly performed indoors. With these trends, it is discovered that some minute particulates, which attracted less attention previously, are causes of several diseases. Especially, it is discovered that the main causes of allergic diseases are furs of an animal, house dust mite and so on. The representative microorganism existing in the living environment of human being and inducing the allergic diseases is mites, especially the house dust mites having the size of about 100 to 300 μm. In
addition, the body wastes of the house dust mites having the size of about 40 μm, and the proteins generated when the carcass of the mite is degraded are also regarded as the main causes of the allergic diseases. Other causes of the allergic diseases include cat fur, cockroach, the body waste of the cockroach, and so on. In "Dust mite allergens and asthma, Report of a Second International
Workshop" (J. of Allergy and Clin. Immunology, vol. 37, pp.1046-1050, 1992) of Platts, Mills, TAE et al, it is disclosed that the air suspended Group I Mite Allergen is closely related with a relatively large stool particulates having the size of 10-40 μ - In addition, in "House dust mite and clinical allergy"(allergy, vol. 11 , part 3, pp.297-308, 1991) of Chun-soo, HONG, it is disclosed that the house dust mite is the main cause of the allergic diseases, and especially, is the main cause of the respiratory allergic diseases in our country. It is also disclosed that the house dust mite may be the only cause of the allergic diseases for ordinary persons.
With these discoveries, the methods to prevent or block the minute allergens are developed in various aspects. Among these methods, the most effective one is to use a fabric having the average pore size of less than 10 jam produced with micro-fibers having a denier of 0.5 or less (For example, see Japanese Laid Open patent No. 11-217745). However, the conventional micro- fiber fabric having minute pores is not suitable for commercial products for living due to the following drawbacks. Representatively, the conventional micro-fiber fabric is produced by simply reducing the pore sizes, which results in the production of the typical rigid micro-fiber fabric. Thus, the conventional micro- fiber fabric makes relatively big frictional sounds, and has an inferior washing-
enduring property. In addition, the pore size of the conventional micro-fiber fabric greatly increases after washing, which reduces the life span of the fabric. As other method to block the minute allergens, the surface of the fabric, which is produced with a natural fiber, can be coated with urethane, vinyl or so on. However, such coated fabric prevents the penetration of not only the minute allergens but also moisture and air. Thus, the fabric is not comfortable when wearing, induces bad-effect on the skin of a user, and thus is not suitable for bedclothes or the like. From the recent research, it is discovered that the conventional fabric having the average pore size of more than 10 μm could not effectively block the minute allergens. For example, in "Evaluation of materials used for bedding encasement: Effect of pore size in blocking cat and dust mite allergen" (J. of Allergy and Clin. Immunology, part I, Vol. 103, pp. 227-231 , February 1999) of John W. Vaughan et al, it is disclosed that the fabric having the average pore size of less than 10 m is required to block the house dust mite allergen, such as Der fl and Der pi, to a desirable level. It is also disclosed that the allergen derived from the cat fur is blocked with the fabric having the average pore size of less than 6 μm.
The micro-fiber fabric disclosed in Japanese Laid Open patent No. 11- 217745 has the average pore size of 4 to 10 μm, an air permeability of 0.5 to 25 cfm measured according to ASTM D-737 (5450), and a moisture permeability of more than 800g/m724h. However, the fabric is not comfortable compared with a fabric produced with a natural fiber, and the pore size thereof increases by about 30% (maximum 12.5 μm) when the fabric is washed 5 times. Therefore, the fabric
is not practically suitable for blocking the allergens.
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention to provide a washing- enduring and high-density micro-fiber fabric for blocking harmful microorganisms and minute particulates derived therefrom.
It is other object of the present invention to provide a washing-enduring and high-density micro-fiber fabric whose pore size is maintained after the fabric is washed 5 or more times, and which has desirable air permeability and moisture permeability as living merchandise.
In order to achieve these objects, the present invention provides a washing-enduring and high-density micro-fiber fabric comprising a micro-fiber fabric which is produced with a synthetic micro-fiber and has a plurality of pores, wherein average size of the pores is 4.0 μm or less after the fabric is weaved, and the sizes of the pores fulfill the condition of the following equation 1 , [Equation 1]
Ha < 20% wherein, Ha represents (Hmax / total number of pores), and Hmax represents the number of pores whose sizes are larger than the average pore size among the total pores.
After the fabric of the present invention is washed 5 or more times, the fabric maintains the average pore size of 4.0 μm or less, and the number of pores having the size of 6.0 μm or more is minimized. The fabric is preferably produced
with a synthetic micro-fiber having a denier of 0.5 or less, and preferably produced by carrying out a cire processing under the conditions of a roller temperature of 65 to 75°C , a fabric moving speed of 65 to 70 m/min, and a roller pressure of 25 to 30 ton after weaving the fabric. The fabric is useful as living merchandise, such as bedclothes, medical clothes, baby clothes, cover for toys, curtains, and so on.
BRIEF DESCRIPTION OF THE DRAWINGS
Figs. 1 is a photograph of the washing-enduring and high-density micro- fiber fabric, which is produced according to Example 1 of the present invention and washed 10 times (The photograph was obtained with a lamp irradiation microscope and with the magnification ratio of 100 times);
Figs. 2 is a graph for showing the pore distribution of the washing- enduring and high-density micro-fiber fabric, which is produced according to Example 1 of the present invention and washed 10 times; Figs. 3 is a photograph of a conventional high-density micro-fiber fabric, which is washed 10 times (The photograph was obtained with a lamp irradiation microscope and with the magnification ratio of 100 times); and
Figs. 4 is a graph for showing the pore distribution of a conventional high- density micro-fiber fabric, which is washed 10 times.
DETAILED DESCRIPTION OF THE INVENTION
A more complete appreciation of the invention, and many of the attendant advantages thereof, can be better appreciated by reference to the following detailed description and the accompanying drawings.
The washing-enduring and high-density micro-fiber fabric according to the present invention is produced by weaving a fabric with a synthetic micro-fiber and by carrying out a post-processing step for the weaved fabric. The preferable synthetic micro-fiber includes polyester micro-fiber, polyester/nylon conjugated and splitted fiber, and so on. The denier of the synthetic micro-fiber for producing the fabric of the present invention is preferably 0.5 or less per a single filament, and more preferably 0.3 or less. When the conjugated and splitted fiber is used in the present invention, the denier means the denier of the splitted single filament. When the denier of the synthetic micro-fiber is more than 0.5, the fabric having a desirable minute pores cannot be obtained. After the fabric is weaved, the postprocessing steps, such as aging, washing, scouring, dyeing, softening, antistatic finishing, cire processing, and so on, are carried out for the weaved fabric. The post-processing steps are particularly important for improving the feeling of the fabric, and the washing-enduring property of the fabric. The cire processing is preferably carried out under the conditions of a roller temperature of 65 to 75 °C, a fabric moving speed of 65 to 70 m/min, and a roller pressure of 25 to 30 ton, and more preferably carried out a under the conditions of the roller temperature of 70 °C, the fabric moving speed of 70m/min, and the roller pressure of 28 ton. When the roller temperature of the cire processing is less than 65 °C , the pore size of the fabric increases un-desirably, and when the roller temperature of the cire processing is more than 75 TJ, the feeling of the fabric becomes rough and hard. When the fabric moving speed of the cire processing is less than of 65m/min, the feeling of the fabric becomes soft, but the fabric could have non-uniform pore sizes.
And when the fabric moving speed of the cire processing is more than of 70m/min, the stiffness of the fabric increases. When the roller pressure of the cire processing is less than 25 ton, the chemicals used for treating the fabric can be remained in the fabric. And when the roller pressure of the cire processing is more than 30 ton, the pore sizes of the fabric increase and become non-uniform due to the snaps of the fiber. In addition, to remove the static electricity on the fabric, the conventional antistatic finishing process can be carried out for the fabric, and the conventional softening and dyeing processes can be further carried out for the fabric.
The washing-enduring and high-density micro-fiber fabric of the present invention, which is produced by above-described process, has the average pore size of 4.0 μm or less after the fabric is weaved, and the sizes of the pores fulfill the condition of the following equation 1 , [Equation 1]
Ha < 20% wherein, Ha represents (Hmax / total number of pores), and Hmax represents the number of pores whose sizes are larger than the average pore size among the total pores. After the fabric of the present invention is washed 5 or more times, the fabric maintains the average pore size of 4.0 μm or less, and the number of pores having the sizes of 6.0 μm or more is minimized.
If the pore distribution (Ha) is more than 20%, it means that the number of the pores, whose sizes are larger than the average pore size, increases. In such case, even if the average pore size is less than 4.0 μm after washing 5 or more
times, a large number of pores whose size is larger than 6.0 μm might exist in the fabric. Thus, the fabric, in which the pore distribution (Ha) is more than 20%, cannot sufficiently block the allergens, such as furs of animals.
On the contrary, the fabric of the present invention maintains the average pore size after washing, and has the air permeability of 1.0 to 30 cfm, and the moisture permeability of more than 1500g/mV24h. Thus, the fabric of the present invention has the feeling similar to the natural fabric, and maintains the average pore size after washing 5 or more times, and effectively blocks the various allergens.
Hereinafter, the preferable examples of the present invention and the comparative examples are provided for better understanding of the present invention. However, the following examples are to illustrate the present invention, and the present invention cannot be limited by the following examples.
[Examples 1-3, Comparative Examples 1-2] Production of high-density micro-fiber fabric using a splitted fiber
9 splits and 0.2 denier micro-fiber (Product of Huvis Co., Ltd, PN DTY 75d/36f) including nylon 1 filament and polyester 8 filaments was treated with a conventional sizing agent (Daehan Oil Chemical Co., Ltd., NEWJET DH-2001 P), and was plain weaved with an air jet loom. The micro-fiber was used as the warp and the weft of the produced fabric, and the produced fabric has the width of 70 inches, and includes 170 micro-fibers per 1 inch.
The produced fabric was scoured at 60 TJ for 40 minutes with a composition produced by adding a scouring agent (scourwet-2002, Daedong oil chemical, Ltd.) to the solution including 0.5g of NaOH per 1 liter of water. The added amount of the scouring agent was 10 g per 1 liter of the NaOH solution. Then, the fabric was aged at 60 TJ for 8 hours, washed with water at 95 TJ for 40 minutes, and dehydrated. Then, the cire processing was carried out for the fabric with a conventional cire processing machine under the conditions of the roller temperature of 70 TJ , the fabric moving speed of 70 m/min, and the roller pressure of 28 ton to produce the high-density micro-fiber fabric. The pore sizes of the produced fabric were analyzed, and 3 kinds of the fabrics (Examples 1-3) whose pore sizes fulfill the condition of equation 1 , and 2 kinds of the fabrics (Comparative Examples 1-2) whose pore sizes do not fulfill the condition of equation 1 were selected. For each Example and the Comparative Example, 100 fabrics having the size of 1 square inches were prepared for further testing.
[Examples 4-6, Comparative Examples 3-4] Production of high-density micro-fiber fabric using a polyester fiber
Except for using a polyester micro-fiber of 65 denier and 204 filaments (Hyosung Co., Ltd. FLAT(WD) & DTY 65D), the high-density micro-fiber fabric was produced according to the method described in Example 1. The pore sizes of the produced fabric were analyzed, and 3 kinds of the fabrics (Examples 4-6) whose pore sizes fulfill the condition of equation 1 , and 2 kinds of the fabrics (Comparative Examples 3-4) whose pore sizes do not fulfill the condition of equation 1 were selected. For each Example and the Comparative Example, 100
fabrics having the size of 1 square inches were prepared for further testing.
[Test Example]
The fabrics of Examples 1-3 and Comparative Examples 1-2 were washed 10 times, and the properties including the average pore size were measured.
The results are shown in Table 1. The same test was carried out for the fabrics of Examples 4-6 and Comparative Examples 3-4. The results are shown in Table 2. To determine the pore sizes shown in Tables 1 and 2, 5 samples were randomly selected from the 100 fabrics having the size of 1 square inches of Examples and the Comparative Examples, and the sizes of 200 pores were measured for each sample, and averaged. The washing was carried out with a conventional 6 1 washing machine in an automatic mode and with using a neutral detergent. The pore size was measured by a method proposed by the present inventors and certified by Korea Merchandise Testing & Research Institute (Certification No.: 20576). The moisture permeability was measured by a water method disclosed in KS K 0594, and the moisture permeability measurement was performed by FITI (Fabric Inspection & Testing Institute), which is an official testing institute of Republic of Korea. The air permeability was measured by a Frazier Method disclosed in KS K 0570-1997, and the air permeability measurement was also performed by FITI.
[Table 1]
[Table 2]
As shown in Tables 1 and 2, the fabric of the present invention maintains the average pore size after washing 10 times compared with the fabric of the comparative examples. In addition, the fabric of the present invention has a narrow pore size distribution, and maintains the desirable moisture permeability and air permeability after washing. Therefore, the fabric of the present invention maintains the allergen blocking property and the soft feeling of the fabric even after washing.
The photograph of the high-density micro-fiber fabric, which was produced according to Example 1 and washed 10 times, was obtained with a lamp
irradiation microscope (magnification ratio: 100 times). The photograph is shown in Fig. 1 , and the pore distribution of the micro-fiber fabric is shown in Fig. 2. The photograph of the conventional high-density micro-fiber fabric, which was washed 10 times, was obtained with the lamp irradiation microscope (magnification ratio: 100 times). The photograph is shown in Fig. 3, and the pore distribution of the micro-fiber fabric is shown in Fig. 4. As shown in Figs. 1-4, the high-density micro-fiber fabric of the present invention maintains the uniform and narrow pore size distribution after washing 10 times.
As described above, the pore size distribution of the fabric according to the present invention fulfills the condition of Equation 1 after weaving. Therefore the fabric maintains the average pore size of 4 μm or less after washing 5 or more times, and the number of pores having the size of more than 6 μm is minimized in the fabric of the present invention. Thus, the fabric of the present invention can effectively block the harmful microorganisms and minute particulates derived therefrom, and practically useful as living merchandise such as bedclothes, baby clothes, and so on.