JP4258319B2 - Food filtration fabric - Google Patents

Description

  The present invention relates to a fabric excellent in filtration performance in the filtration of food, more specifically, a food filtration fabric that can easily filter colored foods such as coffee, tea, tea, wine, fruit or the like at home and can be used repeatedly. It relates to the manufacturing method.

  For example, in the extraction of coffee or tea, for example, a non-woven fabric made of synthetic fibers having a single fiber fineness of about 3.3 dTex, or a bag-like material made of paper is used as the food filter cloth. However, once it was used, it was not reused and was discarded because the pigment of the filtered or extracted food partly adheres and looks bad. In particular, the filter cloth used outdoors, for example, camping, barbecue, etc., was thrown away as it was in a stationary trash can and developed into an environmental and social problem.

  In addition, fabrics made of natural fibers such as cotton, silk, and linen are used as food filter cloths other than the above nonwoven fabric and paper, but the filterability is insufficient, and self-generated fluff is mixed into the food. There are disadvantages such as. In order to prevent self-dusting in such a woven fabric, it is effective to use synthetic fiber filaments, and filter cloths using synthetic fiber filaments have been proposed in the past. For example, Japanese Patent Laid-Open No. 63-171613 The invention described in Japanese Patent Application Laid-Open No. 64-80413 has been proposed.

  In Japanese Patent Laid-Open No. 63-171613, a felt using ultrafine fibers has been proposed, but when used for food filtration, especially coffee and tea are filtered by pouring hot water, the dimensions change, Since stable coffee and tea could not be obtained, it could not be used repeatedly and had to be thrown away once.

  Japanese Patent Application Laid-Open No. 64-80413 proposes an integral structure filter cloth of ultrafine raised hair and reinforcing cloth, but when used for food filtration, there is a problem that the raised hair is mixed into food.

  Japanese Patent Laid-Open No. 3-4912 also proposes the use of a raised fabric, but there is a problem similar to that of Japanese Patent Laid-Open No. 64-80413.

Next, as methods for dyeing using natural pigments, there are, for example, JP-A-3-41167, JP-A-2002-161485, and JP-B-7-96753.
In each of these patent documents, pigments extracted from food, coffee, and the like are used, and the fibers to be colored include natural fibers such as silk, wool, and cotton, and some synthetic fibers such as polyamide fibers. However, no examination has been made on a colored filter cloth made of synthetic fibers using ultrafine fibers.
JP-A 63-171613 Japanese Unexamined Patent Publication No. 64-80413 Japanese Patent Laid-Open No. 3-4912 JP-A-3-411167 JP 2002-161485 A Japanese Patent Publication No. 7-96753

  An object of the present invention is to provide an environment-friendly filter cloth for food that can be used repeatedly and can be easily filtered in a factory or at home, for example, colored food such as coffee, tea, tea, wine, or fruit, and a method for producing the same. It is in.

  The food filtration fabric of the present invention that solves the above problems has the following configuration (1), and as a preferred mode thereof, further has one or more configurations in (2) to (5) in combination. Is.

(1) A synthetic fiber multifilament composite yarn composed of a raw yarn made of ultrafine fibers having a single fiber fineness of 0.01 dTex or more and 1 dTex or less and a crimped yarn made of ultrafine fibers having a single fiber fineness of 0.01 dTex or more and 1 dTex or less. A food filtration fabric characterized in that it is a configured fabric and is colored or dyed with a pigment of food to be filtered.

(2) The water permeation amount of the fabric with ultrapure water is 1 to 10 ml / cm ² / sec, and the rejection rate is 50 to 95% when radio light # 100 of JIS K 0102 method is used. The fabric for food filtration according to (1).

  (3) The length difference between the raw yarn and the crimped yarn constituting the synthetic fiber multifilament composite yarn is 5 to 25%, and the fabric surface or / and the inside ultrafine fibers are entangled. The food filtration fabric according to (1) or (2).

  (4) The food filtration fabric according to any one of (1) to (3), wherein the ultrafine fibers are polyester synthetic fibers and / or polyamide synthetic fibers.

  (5) The food filtration fabric according to any one of (1) to (4), wherein the food is any colored food selected from coffee, tea, wine, and fruit.

(6) A fabric raw machine composed of raw silk made of ultrafine composite fiber and crimped yarn made of ultrafine composite fiber is subjected to ultrafine treatment to make a fabric made of ultrafine fiber, and then subjected to high-pressure water flow. injection to the surface and / or inside the Rutotomoni entangling some or all of the fibers, food filtration fabric according to said colored or Senshokusu Rukoto a dye of food to be filtered (1) Production method.

  (7) The method for producing a food filtration fabric according to (6), wherein a synthetic fiber multifilament composite yarn having a difference in length between the raw yarn and the crimped yarn of 5 to 25% is used.

  (8) The ultrafine composite fiber is a sea-island composite fiber, and the ultrafine treatment is performed with a solvent that dissolves sea components of the sea-island composite fiber (6 ) Or (7). A method for producing a food filtration fabric.

  (9) The method for producing a food filtration fabric according to any one of (6) to (8), wherein the high-pressure water stream is a 3-12 MPa high-pressure water stream injected from a large number of small holes.

  (10) After the ultrafine treatment, the fabric is immersed in a colored food liquid having a pH adjusted to 7 to 4 and colored or dyed at 95 ° C. to 140 ° C. (6) to (9) The manufacturing method of the cloth for food filtration in any one of.

  The food filtration fabric according to the present invention has the above-described configuration, so that it does not enter the food due to fluffing and exhibits excellent filtration performance.

  Such a food filtration fabric of the present invention, for example, in coffee bean extraction, fine particles of coffee grounds are captured in a large amount of voids and exhibits an excellent filtration performance that has not been obtained before, and the filtration part is conspicuous even after use of filtration. Therefore, it is possible to obtain a naturally-friendly filter cloth that is not disposable.

  In the present invention, “for filtration” includes not only the original filtration application but also the extraction application of coffee, tea, and the like.

  Hereinafter, the present invention will be described in more detail.

  The present inventors have intensively studied to obtain a fabric that can solve the above-mentioned problems, and are composed of a synthetic fiber multifilament composite yarn composed of raw yarn made of ultrafine fibers and crimped yarn made of ultrafine fibers. It has been found that such a problem can be solved at once by using a colored fabric and coloring with a pigment in food. In particular, the fabric is more preferably a woven fabric in which some or all of the surface or internal fibers are entangled with a high-pressure water stream.

  The fabric entangled with some or all of the fibers on the surface or inside by such high-pressure water flow has a fine inter-fiber gap between some or all of the constituent fibers due to the entanglement imparting action by jetting the high-pressure water flow. Are formed, and the formed fine inter-fiber voids are also referred to in the art as a micro sponge structure, a micro pocket structure, or the like.

  The ultra-fine fiber used in the present invention is obtained by ultra-fine sea-island type composite fiber, exfoliated split type composite fiber, special polymer blend type composite fiber, or the like by an appropriate method. Various polymers such as those based on polyamide, polyamide, polyacryl, and polyolefin can be used. In the present invention, it is preferable to use a polymer based on polyester or / and polyamide.

  The synthetic fiber multifilament composite yarn used in the present invention is composed of at least two kinds of synthetic fibers. The fibers constituting one of them are raw yarns composed of ultrafine fibers having a single fiber fineness of 0.01 dTex or more and 1 dTex or less, and the other fibers constituting the synthetic fiber multifilament composite yarn have a single fiber fineness of 0.00. A crimped yarn composed of ultrafine fibers that have been crimped by, for example, a temporary twisting process of 01 dTex or more and 1 dTex or less.

  These will be described in detail below.

  First, a crimped yarn made of ultrafine fibers is an important fiber for expressing the excellent filtration performance effect of the present invention, and the effect is usually greater as it is thinner. That is, the surface area of the fiber is large and the number of voids is large. For example, in order to satisfy the effect of capturing fine grounds in coffee extraction, the fineness of the single fiber is preferably as small as possible, 0.01 dTex or more, 1 dTex or less, more preferably The thing of the range of 0.03dTex or more and 0.08dTex or less is good. When the single fiber fineness of the crimped yarn is less than 0.01 dTex, for example, although it is satisfactory in terms of coffee filtration performance, fiber wear occurs due to repeated washing use, and fluff caused by single yarn breakage, etc. Occurrence of food and contamination in food. Moreover, when the single fiber fineness exceeds 1 dTex, it becomes difficult to capture fine debris, and as a result, sufficient filtration tends to be impossible.

  Further, in the present invention, by imparting crimps to the ultrafine fibers by temporary twisting or the like, the single fiber arrangement of each fiber is disturbed, the surface area of the fibers acts greatly, and the porosity is also increased. . In addition, for example, the capture of fine ground coffee is increased and the filtration performance by the fabric is satisfied. When the ultrafine fibers do not have crimps, the single fiber arrangement is not disturbed, and the bulkiness of the woven fabric is reduced, resulting in insufficient filtration performance.

  Crimping to ultrafine fibers can be imparted by applying a crimping process such as a temporary twisting process to the ultrathinnable yarn before the sea removal treatment or split treatment, and is usually 2500 to 4000 revolutions / m. It is carried out by applying a temporary twist, and preferably by performing a temperature treatment at 180 to 200 ° C. In addition, the stretch rate (crimp rate) by crimping is preferably 15 to 40%, and the total fineness of the crimped yarn at that time is preferably 40 dTex or more and 250 dTex or more.

  The raw yarn made of ultrafine fibers, which is another constituent fiber of the present invention, has a single fiber fineness of 0.01 dTex or more and 1 dTex or less, more preferably a single fiber fineness equal to or higher than the crimped yarn made of the ultrafine fibers. belongs to. Here, raw yarn is a term used for crimped yarns composed of the above-mentioned ultrafine fibers, and refers to straight yarns that do not substantially have crimps. This raw silk acts as a raw material for food filtration and constitutes the inner layer portion of the synthetic fiber multifilament composite yarn, contributing to the expansion of the porosity and, for example, the capture of fine coffee beans in coffee extraction. The total fineness of the raw silk is preferably 40 dTex or more and 200 dTex or less.

  Further, these crimped yarn and raw yarn may be used by being aligned or used by being entangled.

  The food filtration fabric of the present invention is composed of a synthetic fiber multifilament composite yarn in which the raw yarn made of the ultrafine fiber and the crimped yarn made of the ultrafine fiber are combined and integrated. Thus, in the present invention, since at least two kinds of fiber yarns are combined, the characteristics can be further emphasized by giving a difference in yarn length to each other.

  For example, the yarn length difference between the raw yarn made of the ultrafine fiber of the present invention and the crimped yarn made of the ultrafine fiber is preferably 3 to 25%, more preferably 8 to 20%. When the yarn length difference between the two yarns is less than 5%, the gap between the fibers is insufficient, and as a result, the filtration performance is insufficient. If it exceeds 25%, the voids increase, but the ultrafine fibers protrude excessively on the surface, so that there is a tendency that the ultrafine fibers are entangled with each other and the single yarn breakage occurs.

  In the fabric of the present invention, the crimped yarn mainly forms the surface layer portion and the raw yarn forms the inner layer portion, but each yarn may exist as it is on the fabric surface or inside, but more preferably. Is more preferably in an entangled state due to entanglement or water jet punching, and voids are generated due to the difference in swelling between the two yarns, and for example, the effect of capturing fine ground coffee beans is further enhanced.

  Since the synthetic fiber multifilament composite yarn used in the present invention is composed of different ultrafine fibers as described above, the crimped ultrafine yarn is selectively exposed on the surface due to the difference in the respective yarn lengths in the fabric state. And increase voids. Therefore, for example, it effectively works to improve the capture ability of coffee beans. In addition, the raw yarn is located on the inner layer side of the crimped yarn, and as a result of causing the crimped yarn to be raised on the surface, the fabric has more voids. For example, fine scum leaked from the crimped yarn on the surface in coffee extraction It has an effective action of reliably capturing in the raw silk part.

  In the present invention, the proportion of the crimped yarn composed of ultrafine fibers in the synthetic fiber multifilament composite yarn is preferably 40 to 80% by weight. If the amount is less than 40% by weight, the surface of the fabric becomes plain, and, for example, the effect of wrapping the capture of fine coffee particles inside is lacking, and if it exceeds 80% by weight, the form stability tends to be lacking. In the present invention, the vicinity of 50% by weight is more preferable. The total fineness of the synthetic fiber multifilament composite yarn is preferably 80 dTex or more and 400 dTex or more. Further, the synthetic fiber multifilament composite yarn may be any synthetic fiber multifilament produced from a single die, or may be obtained by a method such as aligning or twisting.

  The fabric of the present invention, such as a woven fabric, is basically woven using such a synthetic fiber multifilament composite yarn as a background, but other fibers, yarns, etc., as long as the effects of the present invention are not impaired. Can be used in combination.

  Specifically, the synthetic fiber multifilament constituting the synthetic fiber multifilament composite yarn of the present invention may be a polyester fiber, a polyamide fiber or the like, and two or more kinds of materials may be used.

  Examples of the fabric structure constituting the food filtration fabric of the present invention include plain weave, twill weave, satin weave, double weave, tricot, circular knitting, and the like. For example, double weaving, twill weaving, and satin weaving are particularly preferable in order to eliminate the thinness peculiar to fabrics using ultrafine fiber yarns and increase the bulk and to improve the fine ground filter performance of coffee, for example.

The basis weight of the food filtration fabric of the present invention is not particularly limited, but is preferably 100 to 300 g / m ² , more preferably 150 to 250 g / m ² . When the basis weight is 100 g / m ² or less, the bulkiness is poor and the filterability is deteriorated, and when the basis weight is 300 g / m ² or more, the bulkiness is too high and the workability tends to be deteriorated.

The food filtration fabric of the present invention has a water permeability of ultrapure water of 1 ml / cm ² / sec or more and 10 ml / cm ² / sec or less, and is blocked when JIS K 0102 radio light # 100 is used. The rate is 50-95%. More preferably, the water permeability is 3 or more and 8 ml / cm ² / sec or less, and the blocking rate is 55 to 95% when using Radiolight # 100 of JIS K 0102 method.
The amount of water permeation is less than 1 ml / cm ² / sec and the rejection rate exceeds 95%. As a result, for example, in coffee extraction, a large amount of coffee grounds remains on the fabric, and sufficient extraction cannot be performed. In addition, the water permeability exceeds 10 ml / cm ² / sec and the rejection rate is less than 50%. For example, most of the coffee fine particles pass through the fabric, and as a result, sufficient extraction cannot be performed. become.

  Therefore, it has been found that by taking the water permeation amount and the blocking rate within this range, for example, filtration for foods having filtration performance with little performance degradation can be achieved in filtration after repeated washing.

  Further, in order to obtain the water permeation amount and the rejection rate, the weave density also occupies a large factor.

  The coloring of the fabric is important in repeated use. That is, non-colored filter cloth can be used for colored foods such as coffee, tea (fermented tea (black tea), non-fermented tea (green tea), semi-fermented tea (Chinese tea, etc.), etc. When barley tea, pearl barley tea, mate tea, etc., which are generally referred to as tea), wine, fruit, etc. are filtered, only the portion where the liquid is filtered is colored and partially dirty. This is washed and decolored, but it does not return to the original whiteness (color before use of the fabric), so it feels dirty from the viewpoint, and as a result, it becomes undesirably discarded and is actually discarded. However, if the hue of the colored food to be filtered is dyed or colored before filtering, the soiled portion becomes inconspicuous, and the entire hue remains the same even after washing, so it can be used repeatedly without being discarded.

  Next, the manufacturing method of the food filtration cloth of the present invention will be described.

  In the present invention, the composite fiber that can be made ultrafine is a sea-island type composite fiber, exfoliated split type composite fiber, special blend type composite fiber, etc., and then finely processed by ultrafine processing such as chemical peeling, physical peeling, and component dissolution removal. This refers to fibers that can be converted.

  First, for the production of ultrafine fibers, fiber yarns made of ultrafine composite fibers such as sea-island type composite fibers, exfoliation split type composite fibers, and special blend type composite fibers are prepared. One is raw silk, the other is crimped by temporary twisting, etc., aligns both, and gives a yarn length difference if necessary, to make a composite fiber form synthetic fiber A multifilament composite yarn is used.

  Examples of the composite means of both yarns include drawing, twisting and entanglement, but fluid entanglement treatment with air or the like is particularly preferable.

  Next, weaving is performed using this synthetic fiber multifilament composite yarn, and the resulting woven fabric machine is subjected to an ultrafine treatment to obtain a knitted fabric made of ultrafine fibers. As the ultrafine processing, there are means such as chemical peeling, physical peeling, and dissolution removal of one component. For example, when a sea-island type composite fiber is used, it can be made into ultrafine fibers by treatment (desealing) with a solvent that dissolves the sea components of the sea-island type composite fiber.

  Next, in the present invention, if necessary, the ultrafinely treated fabric is preferably subjected to high-pressure water jet and entangled with some or all of the fibers on or inside the fabric.

  Thereby, the filter cloth for foodstuffs of this invention becomes higher density, and further higher filtration performance is obtained. As described above, in order to make the present invention more effective, it is possible to perform a water jet punch process, in particular, to spray a high-pressure water stream on the surface of the fabric subjected to the ultra-thinning process or the dyeing process by sea removal. preferable. Specifically, water that has been filtered and purified is sprayed onto the surface of the fabric through a large number of small holes.

The water pressure is preferably 3 MPa or more and 12 MPa or less, more preferably 4 MPa or more and 10 MPa or less, and most preferably 5 MPa or more and 9 MPa or less.
When the pressure is less than 3 MPa, the processing effect is low, and the entanglement between the fibers is insufficient, and when the pressure is 12 MPa or more, the fibers may be cut to cause fluff.

  Further, the water jet punching process shrinks the woven fabric, so that the bulkiness is imparted and the voids of the ultrafine fibers are increased, so that, for example, the coffee extraction performance is improved.

For example, in the case of a coffee extraction cloth, the color or dyeing of the food filtering cloth may be any stage such as coffee beans before refining or coffee beans or husks during refining, further refined coffee powder or husks remaining after filtering. However, it is preferable to use a coffee other than the husk.
In general, it is difficult to color or dye synthetic fibers, especially polyester-based synthetic fibers, but it is necessary to control the pH by filtering the coffee using hot water and coloring or dyeing it to the extent that it remains on the fabric. Obtained by.
The pH is 7-4, and if it is outside this range, it will not be colored or dyed.

  In addition, although pH adjustment can be adjusted with organic acids, such as an acetic acid, formic acid, and vinegar, for example, an acetic acid can be used preferably.

  Moreover, coloring or dyeing | staining temperature changes with fiber compositions which comprise a filter cloth, and is selected suitably. For example, in the case of a fabric made of polyamide fiber, the temperature is 40 ° C to 98 ° C, preferably 98 ° C. In the case of a fabric made of polyester fiber, the temperature is 100 ° C to 135 ° C, preferably 130 ° C.

  Hereinafter, the present invention will be described in detail based on examples. In addition, the measurement method and evaluation method of various physical properties were as follows.

(1) Measuring method of water permeability The apparatus shown in FIG. 1 was used. The food filtration cloth was previously immersed in distilled water for one day and night to be familiar with water. The fabric 2 was placed on the lower filtration tube 3 and fixed to the upper filtration tube 1 with a clamp. Distilled water is pumped from the tank 6 to the upper filtration tube 1 through the pump 5 and stored. The cock 7 is fully opened while the head height is 500 mm, and 1 to 1.5 liters of passing water is collected in the measuring cylinder 4. To do. At the same time, the fully open time of the cock 7 is measured, and the water permeability K is obtained by the following equation.
K = W / (9.6 × S) (1 × 10 ⁻⁴ ml / m ² / sec)
However, W is the collected passing water (ml), S is the cock full open time (second), and 9.6 is the passing area of the passing water (1 × 10 ⁻⁴ m ² ).

Judgment: ○: 0.5 × 10 ⁻⁴ ml / sec · m ² or more, 5 × 10 ⁻⁴ ml / sec · m ² or less, ×: outside the above range.

(2) Blocking rate:
The rejection was performed according to JIS K 0102. That is, 500 ml of a solution of Radiolite # 100 dissolved in ultrapure water was suction filtered with a filter paper, and the dried product was used as the weight of the standard filtrate. On the other hand, for filtration with a filter cloth, 500 ml or more of the liquid obtained by suction filtration of 500 ml or more of the liquid with a filter cloth is collected, suction filtered with a filter paper, and the dried product is defined as the weight of the filter paper. Asked.
Blocking rate (%) = {1− (BA) / (ba)} × 100
A: Filter paper weight before passing through the filtrate (cN)
B: Filter paper weight (cN) including residual substances in the filtrate
a: Filter paper weight (cN) before permeation of standard solution
b: Weight of filter paper (cN) containing residue of standard solution
Judgment was made with ○: blocking rate of 50 to 95%, x: out of the above range.

(3) Fluff removal:
Judgment was made by visual observation.

(4) Yarn length difference measurement method:
In the measurement of the difference in yarn length, 1.5 m of a synthetic fiber multifilament composite fiber made of raw yarn and crimped yarn is sampled, and then marked at 1 m to separate the raw yarn portion and the crimped yarn portion. A constant load (0.09807 cN / 1.1 dTex) was applied to the lower end of each of the split fibers, and the length of each yarn was measured at the marking portion, and determined by the following equation.
Yarn length difference (%) = {(La−Lb) / Lb} × 100
La: Length of crimped yarn under constant load (m)
Lb: Length of raw silk under constant load (m)
(5) Washing method Using a drum dyeing machine, Kao's detergent “Zab” 2 g / l, hydrogen peroxide (35% industrial) 3 cc / l, sodium hydrogen peroxide 1.5 g / l, temperature 85 Washing was carried out at ± 2 ° C. and a bath ratio of 1:20 for 15 minutes, and then drained and dehydrated, followed by overflow water washing for 10 minutes. After washing with water, it was dried for 20 minutes using a tumble dryer, and this was performed once.

(6) Coloring or Dyeing Durability Evaluation Method The brightness after the washing method (5) was repeated 5 times was expressed as a brightness difference that changed compared to the brightness before washing. The lightness difference measurement was performed using a color difference meter CR-200 manufactured by Minolta Camera Co., Ltd.

  Judgment: ○: Brightness difference (ΔL value) was 3 or less, x: more than 3.

(7) Reuse evaluation method When colored food was filtered by visual observation, evaluation was made based on ○: dirt was not conspicuous as a whole, x: partly dirty.

<Example 1>
The sea-island type composite fiber is a sea-island type polyester with a total fineness of 120dTex, 18 filaments (70 islands / filament), the island component is polyethylene terephthalate, the sea component is 95.0 mol% terephthalic acid as the acid component of the polyester and 5-sodium Fibers made of alkali hot water soluble polyester made of 5 mol% sulfoisophthalic acid copolymer (the ratio of sea islands to 20/80) were used. This sea-island type fiber is crimped by a temporary twisting process (temporary twist number: 3000 T / m, temperature: 180 ° C.), and a raw silk of a sea-island composite fiber having a total fineness of 120 dTex and 18 filaments of the same composition as described above is used as the yarn length. Synthetic fiber multifilament composite raw yarn was obtained by supplying and aligning at a difference of 26% and fluid entanglement treatment (overfeed rate: 1%, air pressure 0.34 MPa).

  This composite raw yarn was used for warp / weft, respectively, to make a 2/2 twill weave fabric (raw machine).

  The raw component is embrittled by maleic acid treatment at 130 ° C. for 30 minutes, and then treated with a sodium hydroxide aqueous solution at 80 ° C. for 45 minutes to completely remove the sea component, and the single fiber fineness is reduced. A woven fabric made of ultrafine fibers of 0.06 to 0.07 dTex was produced.

Next, water jet punching was performed at a water pressure of 9.8 MPa, and the basis weight of the obtained woven fabric was 170 g / m ² . The water permeability of this fabric was 2.3 ml / cm ² · sec, and the rejection was 83.53%, which was good. This woven fabric was put into a solution adjusted to pH 4 with 1 g / l of powdered coffee at Kato Coffee store, adjusted to pH 4 with acetic acid, cooked at 130 ° C. for 30 minutes, and colored or dyed. The resulting fabric has a ΔL value of 1 after 5 washes,
Good durability was exhibited and no fluff was generated. Using this woven fabric, commercial instant coffee beans made by Nestlé Japan Co., Ltd. were extracted with hot water at 95 ° C., and a flavorful coffee liquid was obtained. The filter cloth after extraction was dirty as a whole, and the filtered part did not stand out, and was a good filter cloth that could be reused. The results are shown in Table 1.

<Example 2>
A filter cloth colored or dyed was obtained in the same manner as in Example 1 except that BB Japan SY black tea was used as the coloring or dyeing material. The obtained woven fabric had a ΔL value of 1 after 5 washes, showed good durability, and had no fluff.
When black tea was filtered with this filter cloth, a flavorful black tea liquid was obtained. The filter cloth after filtration was dirty as a whole, and the filtered part did not stand out, and it was a good reusable filter cloth. The results are shown in Table 1.

<Example 3>
The blending ratio of polyester and polyamide (nylon 6) is 50:50, and the single fiber fineness after removal of the sea component is 150dTex, 20 filaments of sea-island type composite fiber of 0.07dTex. A composite yarn was obtained in the same manner as in Example 1, except that the difference was supplied at 7% and the wires were aligned.

A flat double woven fabric (raw machine) was produced using a composite yarn having a total fineness of 300 dTex of the obtained composite yarn. By treating this woven fabric machine with a sodium hydroxide solution at 98 ° C. for 45 minutes, sea components were completely removed, and a woven fabric made of ultrafine fibers having a single fiber fineness of 0.07 to 0.08 dTex was produced. Next, water jet punching was performed in the same manner as in Example 1. The basis weight of the obtained woven fabric was 230 g / m ² .

The water permeability of this fabric was 3.51 ml / cm ² · sec, and the rejection was 82.31%, which was good. This fabric was put into a liquid adjusted to pH 4 with 1 g / l green tea from Seochoen Co., Ltd., and cooked at 120 ° C. for 30 minutes to be colored or dyed. The obtained woven fabric had a ΔL value of 1 after 5 washes, showed good durability, and had no fluff. Using this fabric, green tea from Seochoen Co., Ltd. was filtered with hot water at 90 ° C., and a rich tea liquid was obtained. The filter cloth after filtration was dirty as a whole, and the filtered part did not stand out, and it was a good reusable filter cloth. The results are shown in Table 1.

<Comparative Example 1>
100% cotton filter cloth (woven structure: plain weave) was used. The single fiber fineness was 1.60 dTex and 1.53 dTex in width when expressed in dTex. The basis weight was 210 g / m ² . This fabric had a water permeability of 11.42 ml / cm ² · sec, a rejection rate of 6.22%, and the filtration performance was poor. The quality after 5 washings was fuzzy and inferior. When the same Nestlé beans as in Example 1 were filtered with this filter cloth, coffee grounds remained in the coffee liquor, and only an unpleasant thing was obtained, and the filtered cloth after filtering was partially soiled. It was terribly bad to look at.

<Comparative example 2>
A normal polyester fiber having a total fineness of 100 dTex, 48 filaments, and a single fiber fineness of 2.1 dTex was used. The filament yarn of this normal polyester fiber is crimped by a temporary twisting process (temporary twist number: 3000 T / M, temperature: 180 ° C.), and the ordinary polyester filament yarn having a total fineness of 100 dTex, 48 filaments, and a single fiber fineness of 2.1 dTex. It was aligned with the raw yarn and subjected to fluid entanglement treatment (overfeed rate: 1%, air pressure 0.34 MPa) to obtain a composite yarn.

  This composite yarn was used for warp and weft, respectively, to make a 2/2 twill weave fabric (raw machine). This raw machine was subjected to normal relaxation scouring.

The finished fabric had a basis weight of 225 g / m ² . This fabric had a water permeability of 13.39 ml / cm ² · sec, a rejection of 3.9%, and was inferior in filtration performance. After 5 times of washing, it was good without fuzzing, but when tea was actually filtered, a lot of debris was seen. Moreover, the filter cloth after filtering was partially dirty and had to be discarded. The results are shown in Table 1.

  On the other hand, the filter cloth of Examples 1, 2 and 3 is used to obtain wine by dyeing with other colored foods such as grapes. If it is colored food such as coloring with lemon, it can be colored or dyed by using any food, and a reusable and natural filter cloth can be obtained by filtering the same food.

The food filtration fabric of the present invention can be used as a food filtration fabric that can easily filter colored foods such as coffee, tea, tea, wine, or fruit at home and can be used repeatedly.

Claims (10)

It was composed of a synthetic fiber multifilament composite yarn composed of a raw yarn made of ultrafine fibers having a single fiber fineness of 0.01 dTex or more and 1 dTex or less and a crimped yarn made of ultrafine fibers having a single fiber fineness of 0.01 dTex or more and 1 dTex or less. A cloth for food filtration, characterized in that it is a cloth and is colored or dyed with a pigment of food to be filtered. The water permeation amount of the fabric with ultrapure water is 1 to 10 ml / cm ² / sec, and the rejection rate when using JIS K 0102 method Radiolight # 100 is 50 to 95%. Item 2. A food filtration fabric according to Item 1. The yarn length difference between the raw yarn and the crimped yarn constituting the synthetic fiber multifilament composite yarn is 5 to 25%, and the fabric surface or / and the inside ultrafine fibers are entangled. Item 3. A food filtering fabric according to Item 1 or 2. The cloth for food filtration according to any one of claims 1 to 3, wherein the ultrafine fibers are polyester synthetic fibers and / or polyamide synthetic fibers. The food filtration fabric according to any one of claims 1 to 4, wherein the food is any colored food selected from coffee, tea, wine, and fruit. After a raw fabric consisting of raw yarn made of ultrafine composite fiber and crimped yarn made of ultrafine composite fiber is subjected to ultrafine treatment to make a fabric made of ultrafine fiber, a high-pressure water stream is injected. surface and / or inside the Rutotomoni entangling some or all of the fibers, the manufacturing method of food filtration cloth of claim 1, wherein the colored or Senshokusu Rukoto food to be filtered dye. The method for producing a food filtration fabric according to claim 6, wherein a synthetic fiber multifilament composite yarn having a difference in length between the raw yarn and the crimped yarn of 5 to 25% is used. 8. The ultrafine composite fiber is a sea-island composite fiber, and the ultrafine treatment is performed with a solvent that dissolves sea components of the sea-island composite fiber. The manufacturing method of the fabric for food filtration of description. The method for producing a food filtration fabric according to any one of claims 6 to 8, wherein the high-pressure water stream is a 3 to 12 MPa high-pressure water stream injected from a large number of small holes. 10. The method according to claim 6, further comprising a step of immersing the woven fabric in a colored food liquid having a pH adjusted to 7 to 4 and coloring or dyeing at 95 ° C. to 140 ° C. after the ultrafine treatment. The manufacturing method of the fabric for food filtration of description.