JP7097594B2 - Beverage extraction filter that is transparent in air and water. - Google Patents

Description

The present invention relates to a beverage extraction filter suitable as a filter material for extracting tea bags such as black tea and green tea, coffee filters, and beverages such as soup stock packs.

Conventionally, as a beverage extraction filter for tea bags such as tea and green tea and a coffee filter, a gauze woven fabric made of nylon thread or polylactic acid thread is plain woven, a short fiber non-woven fabric made of thermoplastic synthetic fiber, and a papermaking mainly composed of pulp. Is used.

Generally, a monofilament woven fabric made of nylon 6 or polylactic acid is used as the gauze woven fabric, and the characteristics of the monofilament and the characteristics of the gauze woven fabric are combined to have high transparency. From this, when the monofilament gauze fabric is used as the beverage extraction filter, the consumer can visually check the contained black tea leaves and green tea leaves. However, the gauze fabric has the disadvantage that it is more expensive than the non-woven fabric and papermaking. On the other hand, the non-woven fabric and the papermaking are inferior in transparency as compared with the gauze fabric, and it is difficult to visually recognize the contained black tea leaves and green tea leaves.

Patent Document 1 proposes a fiber sheet made by laminating a non-woven fabric on a non-woven fabric as a filter material having excellent transparency like a gauze woven fabric and capable of increasing high productivity like a non-woven fabric filter. There is. However, in the fiber sheet of Patent Document 1, since the non-woven fabric is laminated on the expensive gauze fabric, the processing cost for laminating is also high, so that the sheet becomes more expensive.

Patent No. 5907219

In view of the above situation, the present invention can visually confirm inclusions such as black tea leaves and green tea leaves when a consumer picks up a beverage filter such as a tea bag in a paper or non-woven fabric that can be manufactured at low cost. At the same time, it is an object to provide a highly value-added beverage extraction filter that can visually confirm the state of inclusions such as tea leaves even during extraction with hot water.

The present inventors have studied to ensure transparency equivalent to that of gauze fabric in non-woven fabrics and papermaking. For example, it is conceivable to improve the transparency by roughening the texture of the non-woven fabric or papermaking, but if the texture is roughened, the filter effect of the contained black tea leaves, green tea leaves, etc. will be adversely affected. .. We also considered improving the transparency by reducing the basis weight, but if the basis weight is reduced, the strength is inferior and there is a risk of tearing during use.

Therefore, we examined various means to improve the transparency without changing the texture and texture, and found that the transparency of the non-woven fabric and papermaking is improved by using a fiber having a specific birefringence as the constituent fiber. The heading has reached the present invention. The present invention is based on this finding.

The present invention is a beverage extraction filter composed of either non-woven fabric or paper-making, wherein the non-woven fabric or paper-making is a fiber made of a thermoplastic resin having a specific gravity of 1.0 or more and a refractive index of 1.65 or less, and a binder fiber. It is characterized in that the constituent fibers are heat-fused together by heat-sealing the binder components of the binder fibers, and the binder fibers are single-phase type binder fibers composed of only the binder components . The gist is a beverage extraction filter having transparency in air and water.

Hereinafter, the present invention will be described in detail.

The beverage extraction filter of the present invention is composed of either non-woven fabric or paper, and the non-woven fabric or paper is mainly composed of fibers made of a thermoplastic resin having a specific gravity of 1.0 or more and a refractive index of 1.65 or less. Here, mainly composed means that it is a main fiber (main fiber) constituting a non-woven fabric or papermaking.

Since the specific gravity of the thermoplastic resin constituting the main fiber is 1.0 or more, it is higher than the specific gravity of water, so when it is used for extraction in hot water, the filter does not rise to the surface of the water and sinks into the water. It can easily function well as an extraction filter.

The thermoplastic resin constituting the main fiber in the present invention is a resin capable of forming a transparent fiber shape by a general melt spinning method, and has a refractive index of 1.65 or less. By setting the refractive index of the thermoplastic resin to 1.65 or less, it is close to the refractive index of water, 1.33. Since the reflection of light is small, the interface between the fiber and water becomes difficult to understand and it becomes easy to assimilate, the inclusions in the filter become easy to see.

Specific examples of such a thermoplastic resin include polyvinylidene fluoride, nylon 6, nylon 66, and polyethylene terephthalate. Further, since the thermoplastic resin used in the present invention is required to have transparency, it is not necessary to add an additive that impairs transparency, and in particular, titanium oxide that whitens the fiber is not added. Therefore, since titanium oxide that inhibits transparency is not added, the fiber becomes transparent in the air.

The above-mentioned thermoplastic resin is fiberized by a generally known melt spinning method, and after stretching, it is cut to a desired fiber length to become a main fiber having desired transparency in air and water. The thickness of the fiber is not particularly limited, but is preferably in the range of 0.5 decitex to 100 decitex. In particular, as the fineness of the fiber becomes finer, the reflection on the fiber surface increases, so that it is preferably 1.0 decitex or more, more preferably 11 decitex or more. Further, the cross-sectional shape of the main fiber may be a circular cross-section or a deformed cross-section, but in the case of a deformed cross-section, an elliptical shape is taken in consideration of selecting a cross-sectional shape that does not impair transparency. Alternatively, a flat shape is preferable.

The fiber length may be determined in consideration of the fineness and processability of the fiber, and is preferably in the range of 3 mm to 25 mm for papermaking fibers and 32 mm to 128 mm for short fiber non-woven fabric fibers. In the case of short fiber non-woven fabric fibers, crimping is applied to the fibers before cutting. The number of crimps is determined in consideration of the fineness of the fiber, but is preferably 7 to 20 per 25 mm of fiber length.
In the present invention, the above-mentioned fibers are used as the main fibers and processed into a non-woven fabric or papermaking. When processing into a non-woven fabric or papermaking, binder fibers are used in order to integrate the main fibers with each other and maintain their morphology. The binder fiber is a composite type composed of a high melting point thermoplastic resin component (hereinafter, also referred to as “high melting point component”) and a low melting point thermoplastic resin component (hereinafter, also referred to as “low melting point component”). Binder fibers are well known, and among them, core-sheath composite binder fibers are well known. As a combination of a high melting point component / a low melting point component, for example, polyethylene terephthalate / low melting point copolymerized polyester, polyethylene terephthalate / polyethylene, and polypropylene / polyethylene are known.

In the present invention, a single-phase type binder fiber composed of only a binder component is used instead of such a composite binder fiber .

In the composite type binder fiber composed of the high melting point component and the low melting point component, it is the low melting point component that functions as the binder component, and the high melting point component does not function as the binder component. When the composite type binder fiber is heat-treated for melt bonding, the low melting point component melts and functions as an adhesive component between the fibers, while the high melting point component maintains the fiber shape without melting and becomes a fiber. Remain. Then, after melt bonding, the binder fiber causes reflection by light at the fiber interface between the melted low melting point component and the high melting point component as a fiber that maintains the fiber morphology, and is transparent in the obtained nonwoven fabric or papermaking. Is easily disturbed. Therefore, in the present invention, a single - phase binder fiber composed of only a binder component is used.

As the binder component constituting the binder fiber, a thermoplastic resin having a low melting point having a melting point difference of 20 ° C. or more from the thermoplastic resin constituting the main fiber is preferable, and more preferably, a low melting point having a melting point difference of 40 ° C. or more. It is a thermoplastic resin of. Specific examples of the binder component include a copolymerized polyester composed of ethylene glycol, isophthalic acid and terephthalic acid. In the copolymerized polyester, as the amount of isophthalic acid copolymerized increases, the crystallinity is lost and the resin becomes an amorphous thermoplastic resin. However, in the binder component, which does not have a clear melting point, the softening point is defined as the melting point. I reckon.

The fineness of the binder fiber is not particularly limited, but is preferably about 1 to 10 decitex in consideration of uniform dispersibility when mixed with the main fiber.

Using the above-mentioned main fiber and binder fiber, a non-woven fabric or papermaking is made. The mixing ratio of the main fiber and the binder fiber is not particularly limited, but the main fiber / binder fiber = 50/50 to 90/10 (mass ratio) is preferable. The main fiber and the binder fiber are mixed to form a dry web or a wet web, and then the binder fiber is melted by heating to heat-bond the constituent fibers to each other to produce a nonwoven fabric or papermaking. As the heating means, it is preferable that heat is applied to the entire surface of the dry web or the wet web. Therefore, heat is applied to the entire surface of the web by passing it through a hot air dryer or between a pair of hot rolls. It is advisable to heat-bond the fibers together.

In the present invention, the basis weight of the nonwoven fabric or papermaking constituting the beverage extraction filter may be appropriately selected from the viewpoint of practical strength and handleability, and is not particularly limited, but is in the range of 10 g / m ² to 60 g / m ² . Is preferable.

Using the above-mentioned nonwoven fabric or papermaking according to the present invention, a tea bag, coffee filter, or the like can be cut and processed into a desired shape, and tea leaves or the like can be encapsulated to obtain a beverage extraction filter. Since the filter of the present invention is composed of thermoplastic fibers during cutting and processing, it can be subjected to fusing treatment, and inclusions such as tea leaves can be easily sealed after inclusion by heat sealing. It is also possible.

The beverage extraction filter of the present invention is made of a non-woven fabric or papermaking whose main fiber is a fiber made of a thermoplastic resin having a specific gravity of 1.0 or more and a refractive index of 1.55 or less. Therefore, when the consumer picks up a beverage filter such as a tea bag, the inclusions such as black tea leaves and green tea leaves can be visually confirmed, and the state of the inclusions such as tea leaves can be visually confirmed even during extraction with hot water. Further, it is possible to provide a beverage extraction filter having high value-added property, which is easily submerged in hot water and has good extractability at the time of use.

It is a schematic plan view of the character board used for the evaluation in an Example. It is a schematic diagram which shows the evaluation situation of transparency (in the air) in an Example. It is a schematic diagram which shows the evaluation situation of transparency (underwater) in an Example.

1: Character board 2: Sample

Hereinafter, the present invention will be described in more detail with reference to Examples. The beverage extraction filters of Examples and Comparative Examples were evaluated by the following methods.
(1) Transparency (in the air)
As shown in FIG. 1, white characters (font) printed with "aiueo" in nine sizes of font sizes: 8, 9, 10, 12, 14, 16, 18, and 20 on a black background. : MS P Gothic) character board is prepared. Then, the evaluation is performed as shown in the schematic diagram showing the evaluation status of the transparency (in the air) of FIG. That is, the sample is mounted at a position where the distance from the position of the character board is 20 mm. Through the sample, the measurer observes the characters "Aiueo" printed on the character board and determines the smallest font size that can be clearly identified.
(2) Transparency (underwater)
White characters (font) printed with "aiueo" in nine sizes of font sizes: 8, 9, 10, 12, 14, 16, 18, and 20 on a black background as shown in Fig. 1. : MS P Gothic) character board is prepared. Then, the evaluation is performed as shown in the schematic diagram showing the evaluation status of the transparency (underwater) in FIG. That is, a petri dish containing water is placed on the character board. Immerse the sample in a petri dish with water so that the entire bottom of the dish is covered by the sample. At that time, make sure that the sample does not have overlapping parts due to wrinkles or the like. The measurer observes the characters "aiueo" through the sample located on the bottom of the chalet containing water, and determines the smallest font size that can be clearly identified.
(3) Refractive index of thermoplastic resin Measured based on the ASTM D542 method.

Example 1
Nylon 6 short fiber with a refractive index of 1.53 to which titanium oxide is not added (fineness: 13 decitex, fiber length: 5 mm, cross-sectional shape: circular) is used as the main fiber, and as a binder fiber, a copolymerized polyester short fiber having a melting point of 110 ° C. Wet web was obtained by mixing fibers (components: ethylene glycol, isophthalic acid, terephthalic acid, fineness: 6.6 decitex, fiber length: 5 mm) at a mixing ratio of main fiber: binder fiber = 70:30. Then, it was heat-treated in a hot air dryer having a temperature of 150 ° C. to obtain a papermaking of Example 1 having a grain size of 45 g / m ² .

Example 2
Papermaking of Example 2 was obtained in the same manner as in Example 1 except that the fineness of the nylon 6 staple fiber, which is the main fiber, was set to 1.7 decitex.

Example 3
Except for the fact that in Example 1, polyvinylidene fluoride short fibers having a refractive index of 1.42 (fineness: 100 decitex, fiber length: 10 mm, cross-sectional shape: circular) to which titanium oxide was not added were used as the main fibers. , The papermaking of Example 3 was obtained in the same manner as in Example 1.

Example 4
Except for the fact that in Example 1, polyethylene terephthalate staple fibers having a refractive index of 1.65 to which titanium oxide was not added (fineness: 1.7 decitex, fiber length: 5 mm, cross-sectional shape: circular) were used as the main fibers. Obtained the papermaking of Example 4 in the same manner as in Example 1.

Comparative Example 1
In Example 1, nylon 6 staple fibers having a refractive index of 1.53 with an amount of titanium oxide added of 0.3% by mass (fineness: 1.7 decitex, fiber length: 5 mm, cross-sectional shape: circular) are used as the main fibers. A papermaking of Comparative Example 1 was obtained in the same manner as in Example 1 except that the paper was obtained.

Table 1 shows the transparency evaluation results of the papermaking of Examples 1 to 4 and Comparative Example 1 obtained.

Claims (3)

A beverage extraction filter composed of either non-woven fabric or paper-making, wherein the non-woven fabric or paper-making is composed of fibers made of a thermoplastic resin having a specific gravity of 1.0 or more and a refractive index of 1.65 or less, and binder fibers. , The constituent fibers are thermally fused by heat fusion of the binder components of the binder fibers, and the binder fibers are single-phase type binder fibers composed of only the binder components. Beverage extraction filter that is transparent in water. The first aspect of claim 1, wherein the fiber made of a thermoplastic resin having a specific gravity of 1.0 or more and a refractive index of 1.65 or less is any one of polyvinylidene fluoride fiber, nylon 6 fiber, and polyethylene terephthalate fiber. Beverage extraction filter. The beverage extraction filter according to claim 1 or 2 , wherein the binder component constituting the binder fiber is a copolymerized polyester composed of ethylene glycol, isophthalic acid and terephthalic acid.

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