JPH09271617A - Filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an overlay type economical disposable filter having excellent extraction efficiency by adding thermally melting binder fibers consisting of a core and a sheath of polymers having a specified melting point and using a filter having a specified filtration velocity and filtration surface area. SOLUTION: This overlay type economical disposable filter contains 20wt.% or more of thermally melting binder fibers consisting of a core and a sheath made of polymers such as polyethylene terephthalate having melting point at lowest 160 deg.C and 110 deg.C, respectively. The filter is made to have filtration velocity not slower than 25 second/150g and not faster than 120 second/150g and the filtration surface area not wider than 80cm<2> . The disposable filter produced in such a manner is used as an overlay type for extracting coffee and tea and sufficiently brings tea leaves or ground coffee beans into contact with hot water and sufficiently swells them and carry out extraction. Consequently, excellent color, taste, flavor, etc., can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The filter of the present invention relates to a top-type disposable filter used for roasting coffee, black tea, green tea and the like.

[0002]

2. Description of the Related Art Filter paper is already widely used as a disposable type disposable filter for roasting coffee, black tea, green tea and the like. However, the filter paper has a drawback that it absorbs valuable flavors such as coffee.

In Japanese Utility Model Publication No. 3-6263, FIG.
The above-mentioned filter for coffee using the non-woven fabric is described. However, this method does not describe the most important filtration rate when roasting coffee.
Nonwoven fabrics generally have a lower density than paper, so the filtration speed of nonwoven fabrics is greater than that of paper. It is presumed that the nonwoven fabric 1 of FIG. 1 cannot control the filtration rate and depends on the filter paper 2 for the control. Therefore, in the case of this example, hot water does not collect in the portion of the non-woven fabric containing the coffee powder, and the disadvantage that the coffee cannot be sufficiently swelled occurs. In addition, the coffee cannot be sufficiently extracted because it is soaked in hot water for a short time. Furthermore, the filter paper 1 still has the drawback that coffee flavor is absorbed.

A black tea pack includes a pyramid type filter using nylon. This is used to make the tea leaves swell by securing a space and make them easier to open, and to reduce the absorption of flavors. However, this type will immerse the pack in hot water, so it is necessary to take out the pack at an appropriate time. If it is taken out too late, it will be dark, and if it is taken out too early, it will be thin, and there is a drawback that you cannot keep an eye on it.

[0005]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide at a low cost a disposable type disposable filter which is used when roasting coffee, black tea, green tea, etc. and has excellent extraction efficiency.

[0006]

[Means for Solving the Problems] When brewing coffee, black tea, green tea, etc., it is important that the coffee and tea leaves are sufficiently contacted with hot water for a proper time to swell. The present invention contains 20% by weight or more of heat-bonding binder fiber (hereinafter abbreviated as "binder") made of a polymer having a core having a melting point of 160 ° C or higher and a sheath having a melting point of 110 ° C or higher, and a filtration rate of 25 seconds / 150g. As described above, the filter has a filtration area of 120 seconds / 150 g or less and a filtration area of 80 cm ² or less.

If the filtration rate is less than 25 seconds / 150 g, the taste becomes light, and if it exceeds 120 seconds / 150 g, the taste becomes deep and bitterness and the like increase. The filtration rate is the most important for controlling the time required for the coffee and tea leaves to be sufficiently contacted with hot water, swelled and appropriately extracted. The filter of the present invention can control the filtration rate mainly in the bottom part of the filter. Therefore, the hot water for extraction is sufficiently retained without creating a space, and an appropriate residence time is secured. If the filtration area exceeds 80 cm ² , it may undesirably protrude in a small-mouthed cup. It is preferably 50 cm ² or less. The filtration area can also be adjusted by partially laminating films.
In the case of coffee, the filtration rate of the filter varies depending on the ground particle size of beans. As the particle size increases, the filtration rate needs to decrease.

The material of the filter is a polymer which is suitable for foods and has no problem. For example, polyethylene terephthalate, polybutylene terephthalate, nylon 6, nylon 66, nylon 12, polypropylene, polyethylene and modified products thereof. These polymers may contain additives that are not a problem in food hygiene. For example, there are colored pigments such as titanium oxide that render the polymer opaque.

The material of the filter may be a non-woven fabric as a filtering portion and may be partially in a film form. This non-woven fabric contains a binder. As the binder, a polymer having a core polymer having a melting point of 160 ° C. or higher, preferably 200 ° C. or higher is used. For example, polyethylene terephthalate,
Polybutylene terephthalate, nylon 6, nylon 6
6, Nylon 12 and modified products thereof. A polymer having a melting point of 110 ° C. or higher, preferably 130 ° C. or higher is used as the sheath polymer. For example, modified products of polyethylene terephthalate or polybutylene terephthalate, polypropylene, polyethylene and modified products thereof. The melting point of the core polymer is selected to be 20 ° C. or more higher than that of the sheath polymer. If the difference between the melting points is small, a drawback that shrinkage becomes large during heat fusion tends to occur.

The nonwoven fabric of the filter contains at least 20% by weight of the above binder. If there is little binder, heat fusion will be insufficient. It is preferably 30% by weight or more, more preferably 50% by weight or more. As the fibers other than the binder, fibers of a polymer having a melting point equal to or higher than that of the core polymer of the binder are used. In terms of heat adhesion, the fibers other than the binder are preferably the same type of polymer as the sheath polymer. For example, if the sheath of the binder is a polyethylene terephthalate modified product, polyethylene terephthalate may be used for the fibers other than the binder. If the type of polymer is different, the adhesiveness is significantly reduced, so it is necessary to mix a large amount of binder. It is preferably 30% by weight or more.

The thickness of the binder and other fibers used in the nonwoven fabric of the filter affects the filtration rate. If the fiber is too thick, the texture of the non-woven fabric becomes rough and the filtration rate tends to be too high. Further, fine powder of coffee or tea leaves may pass through. Therefore, the average fiber thickness is preferably 3.5 denier or less. More preferably 2
It is less than denier. Since the filtration rate of the non-woven fabric is different depending on the thickness of the fibers used, it is preferable to select the unit weight so that the filtration rate is appropriately maintained. Generally 200-400
g / m ² is good.

The filtration speed of the filter is also affected by the density of the nonwoven fabric in the filtration portion. Although the density of the non-woven fabric is influenced by the thickness of the constituent fibers, the density of the non-woven fabric is also increased by the press working such as embossing and the filtration speed is greatly influenced. That is, the filtration rate can be controlled by the distribution of the size of the fiber gap, the thickness and the area.

The non-woven fabric may be formed into a film depending on the pressing conditions of the non-woven fabric, but it does not cause a problem if an appropriate filtration rate can be obtained as a whole. It may be preferable because the molding strength is increased. In the same sense, a non-woven fabric may be used as a filtration portion on a part of the film, or a perforated film may be laminated to adjust the filtration rate of the filtration portion. When dripping, the filtration rate can be increased also by providing the grooves 6, the projections 7, etc. so that the filtrate is collected as shown in FIG.

By forming the filter into a bag shape as shown in FIG. 2, an appropriate amount of coffee, black tea, green tea or the like can be contained in the bag. At this time, it is preferable that the filtration speed of the nonwoven fabric 1 on the dropping surface is lower than that of the nonwoven fabric 4 on the upper surface. In the opposite case, the hot water in the bag will drip,
Do not fully soak coffee, black tea, green tea, etc., and in extreme cases bypass will occur. When the non-woven fabric 1 on the dripping surface and the non-woven fabric 4 on the upper surface are made of the same kind of polymer binder, it is not necessary to use an adhesive for sealing and can be sealed by heat bonding, which is economically preferable. When storing coffee, tea, green tea, etc. in the bag, it is advisable to pack the filter with a film having low moisture permeability and oxygen permeability.

The filter can be molded by hot press molding such as drawing. Vacuum forming for drawing
There is crimp molding. At the time of molding, it is preferable that the content of the binder in the non-woven fabric is 30% by weight or more, preferably 50% by weight or more, since the drawing can be deepened and fine molding such as protrusions can be performed. Although the molding temperature varies depending on the processing temperature of the binder, it is usually heated to the melting point of the binder of 15 ° C. or higher for molding.

The method of manufacturing the non-woven fabric is needle punching,
There are thermal bonding and a method of using them together. In drawing, if the entanglement between fibers is too large, it becomes difficult to draw deeply, so it is advisable to appropriately select the number of needles to be driven, the depth, and the shape of the needle. Further, in the case of draw forming, it is preferable that there is no anisotropy in the plane direction of the nonwoven fabric. If there is anisotropy, unevenness in thickness tends to occur due to squeezing, leading to unevenness in filtration speed. In order to reduce the anisotropy, a large amount of crosslay may be performed at the time of manufacturing the nonwoven fabric and appropriate drawing may be performed. The tensile strength of the anisotropy is preferably 20% or less, more preferably 10% or less.

The filtration rate of the filter was determined by measuring the passage rate of hot water at 85 to 95 ° C. in the number of seconds required for passage as shown in FIG. Also, the taste test is based on the monitor's color, taste,
A flavor sensory test was conducted and evaluated.

[0018]

The top-mounted filter of the present invention is easy to handle, has excellent color, taste, and flavor when roasted coffee, tea, green tea, etc., and can be easily molded.
Economically advantageous.

[0019]

【Example】

Example 1 A polyethylene terephthalate core having a melting point of 255 ° C., a polyethylene terephthalate-modified binder having a melting point of 130 ° C., a binder of 2 denier 51 mm composite fibers and polyethylene terephthalate staple 1.5 denier 51 mm were mixed and carded, followed by a crosslay, The mixture was drawn and needle punched at a rate of 40 / cm ² by a standard method to change the mixing ratio, thereby producing a nonwoven fabric having a basis weight of 200 g / m ² . This non-woven fabric is molded with a molding machine at a mold temperature of 180 ° C., the entrance diameter is 4 cm, the bottom diameter is 3 cm, and the depth is 1
cm, and the thickness of the bottom was 1 mm.
The clearance of the other portion was reduced to 0.5 mm, and the filter was manufactured by forming it into a film to give rigidity. 8 g of finely ground commercial coffee powder for filter drip was placed in the dish and placed on a coffee cup. From above, 150 g of 90 ° C. hot water was poured to brew the coffee. The filtration time and taste of 150 g of hot water were tested, and the results are shown in Table 1. Test No. The comparative product of No. 1 had a bottom thickness of 2.7 mm. 2 is 1.
It could be molded to a thickness of 5 mm and all others to 1 mm. Test N
o. No. 1 had an inappropriate filtration time because the coffee grounds were too large.

[0020]

[Table 1]

Example 2 Test No. 1 of Example 1 In the same manner as in 3, the filter was manufactured by changing only the basis weight of the non-woven fabric, the filtration time and the taste were tested, and the results are shown in Table 2. Test No. No. 7 was not suitable because the filtration time of the filter was too long.

[0022]

[Table 2]

Example 3 The test No. of Example 1 was changed by changing the particle size (bulk density) of the coffee powder. In the same manner as in 3, the denier of the binder fiber was changed to 4d, a filter having a short filtration time was manufactured, and the filtration time and the taste were tested. Table 3 shows the results.

[0024]

[Table 3]

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a known filter.

FIG. 2 is a sectional view of a bag-shaped filter of the present invention.

FIG. 3 is an example in which the grooves 6 and the protrusions 7 of the filter of the present invention are installed on the nonwoven fabric on the dropping surface.

FIG. 4 is a schematic diagram of measurement of a filtration test of a top-mounted filter.

[Explanation of symbols]

 1 Non-woven fabric on dripping surface 2 Filter paper 3 Coffee powder 4 Non-woven fabric on top 5 Edge 6 Groove 7 Protrusion 8 Filter receiver 9 Filter

Claims (2)

[Claims] 1. The core has a melting point of 160 ° C. or higher and the sheath has a melting point of 110.
Heat-bonding binder fiber made of polymer above ℃ 20
% Or more, the filtration rate is 25 seconds / 150 g or more,
120 seconds / 150g or less, filtration area 80 cm ²
The filter that is: 2. The filter according to claim 1, wherein the polymer is polyethylene terephthalate, polybutylene terephthalate, nylon 6, nylon 66, nylon 12, polypropylene, polyethylene and modified products thereof.