WO2008130099A1

WO2008130099A1 - Sanitary cloth made of hemp

Info

Publication number: WO2008130099A1
Application number: PCT/KR2008/001182
Authority: WO
Inventors: Ju-Hwan Kim
Original assignee: Ju-Hwan Kim
Priority date: 2007-04-18
Filing date: 2008-02-29
Publication date: 2008-10-30
Also published as: KR100806033B1

Abstract

The present invention provides an elastic sanitary fabric made of hemp, wherein the fabric is characteristically formed by blending the hemp fiber with at least one general fiber selected from cotton, rayon, polyester and wool at a certain weight ratio for spinning, resulting a blended spun yarn, and forming a fabric by using the blended spun yarn as a weft or a warp or a pile yarn. According to the present invention, it is possible to obtain a low-cost fabric made of hemp which shows characteristic effects of hemp such as antibacterial activity, deodorization effect, far-infrared emission and the like, while making up for general defects of hemp with complementary qualities of other general fibers.

Description

Description SANITARY CLOTH MADE OF HEMP

Technical Field

[1] The present invention relates to a fabric made of hemp, specifically to an elastic sanitary fabric made of hemp which has excellent antibacterial activity and deodorizing function, as well as good elasticity and surface feeling. Therefore, it is possible when made to a sheet or garment form, to generally give nice and comfort feeling to the user without irritating the skin; to achieve homogenous dyeing without brindles at one time; to make the shrinkage rate at the weft and warp direction uniform; and to be washable in water.

[2]

Background Art

[3] Hemp is one of plants that have a long history of cultivation, mainly for obtaining fibers. One representative fabric made of hemp is hemp cloth.

[4]

Disclosure of Invention Technical Problem

[5] Hemp cloth has great air permeability and perspiration absorptiveness, while it has poor elasticity or stretch, and a coarse surface giving rough feeling, thus it has been used in summer clothes or shroud. Usually, hemp cloth is high-priced, and it is needed to repeat a dyeing process many times to obtain uniform color, owing to its excellent perspiration absorptiveness which also requires a large amount of dye.

[6] For the above-mentioned problems such as high price and its attributes, hemp has not gained popularity so far in spite of its long history as a fabric.

[7] As prior arts where the present invention pertains, there are Registered Korean utility model No. 20-0219825 (entitled 'underpants made of hemp yarn') and Registered Korean utility model No. 20-0219826 (entitled 'shirts comprising hemp yarn').

[8] Although the above two registered utility models are different in the subject of utility model, i.e. underpants and shirts, they share the same technical scope in terms that the fabric is formed by using a blended spun yarn containing a certain amount of hemp fiber as a warp and one elastic fiber selected from cotton, wool, rayon, silk and nylon as a weft.

[9] Such technical constitution of above prior arts, however, has a problem in yarn maintenance so as to prevent the two different types of yarns from being mixed together, i.e. such that a weft and a warp are managed separately. Further, since it is difficult to spin two different types of yarns at the same thickness, overall efficiency of the spinning and weaving processes could be lowered. The fabric made of a blended spun yarn containing hemp fiber as a warp and a general yarn which does not contain hemp fiber such as a weft, for example silk, has different shrinkage rates in the weft direction and the warp direction. Therefore, it is difficult to expect the weave and the shape of the resulting fabric. Such defects hinder the quality control of fabric, and further need post-treatment such as a shrink-resistant treatment, which raises cost of the resulting fabric. From a standpoint of consumers, they should be fully aware of the laundry method for such fabric. Further, such products are usually not water-washable, consumers should use the cleaner's and it will cause laundry cost. Since both utility models mentioned above use two yarns different in their dyeing quality, i.e. a weft formed by a general yarn and a warp formed by a blended yarn comprising a certain amount of hemp fiber, when carrying out fabric dyeing, the warp which has relatively higher hygroscopicity is dyed light which causes brindles in the warp direction, thereby deteriorating the dyeing quality of the fabric. As a result, such fabric needs to be dyed at least twice, until the hemp fiber sufficiently absorbs dye, and it also raises the fabric price.

[10] In the meantime, in both of the utility models mentioned above, the yarn is a blended spun yarn formed by twisting two yarns which already have been completely formed, i.e. a lengthy hemp fiber and a general fiber. In this case, the resulted fabric exhibits elasticity as much as that of the hemp fiber, without any improvement in elasticity.

[H]

Technical Solution

[12] The present invention has been designed to overcome problems of conventional fabric made of hemp, for example, difficult maintenance of yarn, problems related with processing such as dyeing or the like, or shrinkage after laundry. According to the present invention, such intrinsic defects of hemp fabric can be overcome by other complementary qualities of general fibers, while maintaining the advantageous effects of hemp such as antibacterial activity, deodorization effect, far-infrared emission, thereby being possible to obtain a cheap fabric with reduced price which can be popularly used.

[13] For achieving such technical objects, the present invention characteristically forms a fabric made of hemp by blending the hemp fiber with at least one generally used fiber selected from cotton, rayon, polyester and wool at an appropriate weight ratio for spinning, resulting a blended spun yarn, and forming a fabric by using the blended spun yarn as a weft or a warp or a pile yarn, wherein the hemp fiber generally has poor elasticity and gives uncomfortable feeling when being worn, while showing excellent antibacterial and deodorization effect. [14] It is preferred to assemble a hemp staple fiber which has an average fiber length of

10cm or less together with a general staple fiber at an appropriate weight ratio, forming a blended spun yarn, and then a fabric can be woven by using the blended spun yarn as a weft or a warp or a pile yarn.

[15] At this time, the weight ratio of the hemp fiber is preferably 5-40% and more preferably 17.9-40% of the total weight of the blended spun yarn.

[16] Further, the elastic sanitary fabric made of hemp is characterized by having 99.2% or more of the reduction rate of bacteria in 8 hours after an antibacterial effect test according to KS K 0693-2006 method using Staphylococcus aureus (ATCC 6538) and Klebsiella pneumoniae (ATCC 4352).

[17]

Advantageous Effects

[18] According to the elastic sanitary fabric made of hemp of the present invention constituted as above, it is possible to make the most of desirable functions of hemp, while complementing or eliminating problems of hemp related to dyeing and washing by using a general fiber together.

[19] Further, it is possible to provide various fabrics made of hemp with a variety of functions and prices which can meet the consumer needs, by adjusting the amount of a general fiber which is relatively low in price, thereby being capable of popularizing the fabric made of hemp. For example, provided that the content (percentage of weight) of hemp is constant, a fabric containing a rather increased amount of cotton may be offered to those who want good and soft feeling when worn, and a fabric having an increased amount of polyester may be offered to those who want a cheap and durable fabric.

[20] The fabric made of hemp according to the present invention per se exhibits antibacterial activity and deodorization effect owing to the specific characteristics of the material, i.e. hemp, thus it may be desirably used in public facilities used by many unspecified persons. For example, it can be used as those needed to be hygienically clean such as a bed sheet, a pillow case or a towel in a hotel or hospital. Brief Description of the Drawings

[21] Fig. 1 shows the fabric weave of a general fabric in an elastic sanitary fabric made of hemp according to the present invention.

[22] Fig. 2 shows the fabric weave of a pile fabric in an elastic sanitary fabric made of hemp according to the present invention.

[23] [Numerals used in the figures]

[24] 1. warp

[25] 11. ground warp [26] 20. weft

[27] 30. pile yarn

[28]

Mode for the Invention

[29] Hereinafter, an elastic sanitary fabric made of hemp according to the preferred embodiments of the present invention is further illustrated, making reference to the attached drawings. In the following examples, by referring "hemp" it is intended to rather focus on its function, and by referring "hemp" (staple) fiber", it is focused on the length so as to be differentiated from the yarn (hemp yarn).

[30] Example 1 : Ordinary woven

[31] Fig. 1 is a magnified view of the weave of an ordinary fabric according to the present example. The blended spun yarn used as a warp(lθ) and a weft(20) in the figure, was spun by blending fibers at the weight ratio of 64.5% of cotton staple fiber; 17.9% of hemp staple fiber; and 17.6% of rayon staple fiber.

[32] After weaving a fabric with the blended spun yarn, an organoleptic test was carried out with the resulted fabric by 20 participants. All of the participants said that the characteristic rough feeling of hemp fiber was reduced, owing to the use of rayon, and the fabric gave smoother feeling.

[33] Further, when forming underwear from said fabric, all of the participants answered that they could sense soft and comfort cotton feel without irritation to the skin, and its perspiration adsorption was felt like better than 100% pure cotton.

[34] Further, the present applicant subjected the fabric to a dyeing and a washing test, respectively. It was found that the color developed after dyeing and shrinkage after washing were uniform at both direction of weft(20) and warp(lθ), owing to the use of a single type of blended spun yarn for both weft(20) and warp(lθ).

[35] Additionally, as compared to dyeing of 100% pure cotton fabric, it required little more dye, just as much as it would not raise the fabric price.

[36] Example 2 : Pile woven

[37] Fig. 2 is a view showing the weave of a pile fabric according to the present example.

[38] As illustrated, the pile fabric of the present example which is woven by a weft (20) and alternately used ground warp(l 1) and pile yarn(30) as a warp, is characterized by having loops formed on one or both sides of the fabric. In this example, a blended spun yarn same as in the example 1 was used as the ground warp(l 1), pile yarn(30) and weft(20). However the blended spun yarn used for a ground warp which forms the ground of the pile fabric and weft may be, if necessary, replaced by a yarn spun out of at least one general fiber selected from cotton, polyester, rayon and wool, while maintaining the blended spun yarn used as the pile yarn that directly contacts with the skin. By doing so, for example, when a blended spun yarn comprising hemp fiber is used as weft, pile yarn and warp, respectively, it is possible to form an elastic sanitary fabric with an improved antibacterial activity and deodorization effect which are specific characteristics of hemp. When the blended spun yarn is only used as a pile yarn in the fabric, the price of the resulted hemp fabric can be reduced.

[39] Antibacterial activity

[40] For confirming whether the fabric of Examples 1 and 2 has the antibacterial activity, deodorization effect and far-infrared emission, the present applicant asked KIFA (Korea Institute of Far infrared Applied estimation) to test the fabric. The following results were obtained.

[41] 1) Antibacterial activity test (test on fabrics K S K 0693-2001)

[42] In 18 hours, the reduction rate of bacteria on both of Staphylococcus aureus and

Klebsiella pneumoniae was 99.9%.

[43] 2) Deodorization rate (gas indicator tube method)

[44] In 2 hours, decrease in ammonia odor was 99.8%.

[45] 3) Far-infrared emission (K F I A- F I -1005)

[46] Emission of 0.859

[47] From the test results, it can be recognized that the fabric of Examples 1 and 2 is excellent in terms of antibacterial activity, deodorization effect and far-infrared emission.

[48] Further, in order to know how the antibacterial activity of the elastic sanitary fabric made of hemp changes depending on the content of hemp, and to confirm whether flax which has similar qualities to hemp also shows antibacterial activity, the present applicant weaved two types of control fabrics in which hemp was not used (hereinafter, referred as control groups 1 and 2), and three types of comparative fabrics in which hemp was used (hereinafter, referred as comparative groups 1, 2 and 3), and asked KIFA to test the control and comparative groups.

[49] In the meantime, the fabric having 17.9 % of hemp based on the total weight of the fabric from Examples 1 and 2 showed 99.9% of the reduction rate of bacteria after a test period of 18 hours. Therefore, a shorter period of 8 hours compared to the standard test (KS test) period was employed, and the test method was carried out according to KS K 0693-2006 (antibacterial activity test). In the following table 1, it should be noted that % of each fiber is the weight ratio of the fiber of interest in the whole fabric.

[50]

[51] Table 1 [Table 1] [Table ]

[52] [53] As it can be seen from the results of the reduction rate of bacteria in the above Table 1, the fabric made of 100% cotton, (i.e. containing no hemp) (Control 1) and the fabric blended with flax (Control 2) appears to hardly have antibacterial activity.

[54] In the meantime, it was found that the fabric comprising hemp was not significantly affected by the content of hemp as well as the test period, and it showed great reduction rate of bacteria as high as 99% or more. Considering that the period of a general antibacterial activity test in fabric is 18 hours (based on KS antibacterial activity test), it can be deduced that even half amount of hemp used in the comparative group 1 would achieve 99% or more of the reduction rate of bacteria in an 18 hour- period antibacterial activity test, since the comparative group 1 showed 99.9% of the reduction rate of bacteria in an 8 hour-period antibacterial activity test. With regard to the reduction rate of bacteria, therefore, taking the time reduction of the test into consideration, the minimum content of hemp is desirably 5% or more that is less than half of 17.9%; preferably 9% or more that is about the half of 17.9%; more preferably 17.9% or more that is the amount used in the comparative group 1.

[55] The reason why the present applicant reduced the test period of the antibacterial activity test to 8 hour in the control groups and comparative groups, is that, in case that the elastic sanitary fabric of the present invention is used as a bed sheet, the elastic sanitary fabric may be not in contact with the body of a user for about 8 hours, considering the general pattern of people's daily lives, and it was considered important to keep the antibacterial activity for about 8 hours for the hygiene.

[56] Surface feeling [57] For studying the surface feeling of a fabric, depending on the content of hemp, 20 persons participated in this study, wherein 5 of them were persons working in this field of art where the present invention pertains, and other 15 persons were not related to the fabric industry.

[58] In the test, three types of blended spun yarns different in the content (percentage of weight) of hemp were prepared, and then three types of general fabric were woven by using each type of the resulted blended spun yarn for a weft and a warp, respectively. The test was carried out such that each participant touches each test fabric and described the feeling.

[59] The results were summarized in the following Table 2. [60] [61] Table 2 [Table 2] [Table ]

[62] [63] From the results as shown in Table 2, it can be known that when 55% or more of hemp was used in the fabric, most of people recognized the hemp feel that is rather rough and cool, and when 30% or less of hemp was used, most of people recognized the cotton feel. It cannot be conclusively said that feeling provided by cotton is better than that provided by hemp. However, considering the fact that most of underwear materials directly coming into contact with the skin are cotton, it is obvious that cotton gives better surface feeling in terms of preference. Therefore, in order to achieve that more than half of the participants sense cotton feel, the range of hemp content may be estimated from the results shown in Table 2. By applying mathematical calculation, in proportion to the test results of Table 2, the content of hemp in the fabric is preferably not more than 40%, preferably not more than 30%.

[64] Weaving quality and price competitiveness [65] As mentioned above, when the proportion of hemp exceeds 55%, most of people recognized hemp feel and the price will be increased by 20% or more as compared to fabrics woven by 100% general fibers. This is because the hemp price is usually more expensive than general fibers such as cotton, rayon, polyester by 40% -50%. The higher the proportion of hemp, the more care about humidity should be taken during weaving, and the operation rate of a weaving machine should be lowered so that the blended spun yarn may not cut, thereby lowering workability. Since hemp usually absorbs more dye than other general fibers, the higher the proportion of hemp in a fabric made of hemp, the more the cost for dyeing increases in significant way as compared to fabrics woven by general fibers.

[66] Therefore, in terms of cost, surface feeling and weaving quality, the proportion of hemp is desirably restricted to a certain range.

[67] In this regard, the present applicant has researched the fabric price, tactile feel and weaving quality by weaving various types of hemp fabrics, and it was found that ratio of hemp used in the fabric was preferably in the range of 5-40%. In other words, within the range of 5-40%, it was possible to weave fabric without supplying humid that is for preventing cutting of yarn (thread), while maintaining good antibacterial activity that is specific characteristic of hemp. Further, the weaving rate was raised as much as that of cotton; cost for dyeing was similar to cost for dyeing 100% pure cotton fabric; and the shrinkage rate after washing was 3-5%, which is similar to shrinkage of cotton fabric.

[68]

Industrial Applicability

[69] According to the elastic sanitary fabric made of hemp of the present invention, defects of hemp such as being easily-creasable, and poor flexibility and elasticity, may be complemented by the qualities of polyester fiber, while maintaining the characteristic qualities of hemp such as antibacterial activity, deodorization effect and far- infrared emission.

[70] Further, it is possible to provide a variety of hemp fabrics which can be popularly used at lower price, by adjusting the content of hemp.

[71] Still further, in the case of an ordinary woven fabric, the maintenance of yarn is much easier since it uses just single type of blended spun yarn.

Claims

[1] An elastic sanitary fabric made of hemp wherein the fabric is characteristically formed by blending the hemp fiber with at least one general fiber selected from cotton, rayon, polyester and wool at a certain weight ratio for spinning, resulting a blended spun yarn, and forming a fabric by using the blended spun yarn as a weft or a warp or a pile yarn.

[2] The elastic sanitary fabric made of hemp according to claim 1, wherein the weight ratio of the hemp fiber is 5-40% of the total weight of the blended spun yarn.

[3] The elastic sanitary fabric made of hemp according to claim 2, wherein the weight ratio of the hemp fiber is 17.9-40% of the total weight of the blended spun yarn.

[4] The elastic sanitary fabric made of hemp according to any one of claims 1 to 3, which has 99.2% or more of the reduction rate of bacteria in 8 hours after an antibacterial effect test according to KS K 0693-2006 method using Staphylococcus aureus (ATCC 6538) and Klebsiella pneumoniae (ATCC 4352).