JP7021188B2 - Coffee filter and crepe paper - Google Patents

Description

The present invention relates to a coffee filter for extracting and filtering coffee beverages from ground powder of roasted coffee beans.

Coffee filters made of paper, flannel (cloth), metal, etc. are used to extract and filter coffee beverages from ground powder of roasted coffee beans. Among these, paper coffee filters are widely used because they are disposable, hygienic, and easy to handle.

Paper coffee filters are required to have a drainage that can efficiently filter coffee beverages and a wet strength that does not tear even when lifted while containing water-containing and heavy coffee bean powder in a wet state. Will be done. However, it is difficult for a base paper made of only general wood pulp to have both the drainage and wet strength required for a coffee filter. Therefore, a general paper coffee filter is formed of a base paper containing 75 to 90% by mass of wood pulp and 25 to 10% by mass of hemp pulp. Since hemp pulp is thinner and longer than wood pulp, by blending hemp pulp, it is possible to obtain a base paper suitable for coffee filter use, which is excellent in drainage and wet strength. In paragraph 0007 of Patent Document 1 below, "hemp pulp with a large fiber diameter" is described, but the fiber diameter of hemp pulp is smaller than that of wood pulp, and this description is an error.

Here, hemp pulp is pulp obtained from leaf vein fibers such as Manila hemp and sisal hemp, and bast fibers such as cannabis, flax and kenaf, but Manila hemp is generally used as a raw material for papermaking. Is. Manila hemp production is virtually limited to the Philippines, Ecuador and Costa Rica. The production area of Manila hemp is limited, and the supply is unstable because the production volume will decrease significantly when natural disasters such as diseases, insects, tropical depressions and droughts occur. Also, hemp pulp is very expensive compared to wood pulp.

Therefore, there is a demand for a coffee filter that does not use hemp pulp. For example, Patent Document 1 describes an invention of a coffee filter paper for a vending machine composed of softwood bleached pulp and mercerized wood pulp. The coffee filter paper described in Patent Document 1 is for vending machines. In a vending machine, coffee filter paper is sandwiched between two cylinders, coffee bean powder and hot water are put in the cylinders, pressure is applied, and suction is performed to extract coffee beverages. Therefore, the coffee filter paper for vending machines is coated with a sizing agent in order to prevent liquid leakage between the cylinder and the filter paper, so that it is difficult to get wet, and crepe processing that causes unevenness that causes liquid leakage is not performed. Coffee filter paper for vending machines is difficult to filter water naturally due to its high size, but the basis weight is about 20 to 30 g / m ² for improving the filterability during pressurization and suction and for mechanical suitability. thin. Further, since the coffee filter paper for vending machines is roll-fed in a wet state, high wet strength is required. As described above, the coffee filter paper for vending machines is a separate article having differences from the coffee filter of the present invention, such as a thin filter paper, difficulty in natural filtration, and no crepe.

Patent Document 2 describes an invention of a coffee filter made of a base paper containing unbleached pulp, bleached pulp, and linter pulp. Since linter pulp has a lot of binding, it needs to be beaten before use. Linter pulp has the same length as hemp pulp and a slightly thicker fiber diameter, and coffee filters containing linter pulp have lower strength and filtration speed than coffee filters containing hemp pulp. Is presumed to be faster.

Japanese Unexamined Patent Publication No. 6-277148 Japanese Unexamined Patent Publication No. 2005-56961

An object of the present invention is to provide a coffee filter capable of stable production.

The means for solving the problems of the present invention are as follows.
1. 1. It consists of crepe paper containing 80% or more of softwood pulp with respect to the total amount of pulp.
A coffee filter in which the softwood pulp has an average lumen ratio of 0.50 or more and 0.70 or less.
2. 2. 1. The wet paper strength enhancer is contained in an amount of 0.05% by mass or more and 0.70% by mass or less based on the total amount of pulp. The coffee filter described in.
3. 3. The crepe paper is characterized in that the freezing time is 8 seconds or more and 20 seconds or less. Or 2. The coffee filter described in.
4. The crepe paper is characterized by having a wet tensile strength of MD 0.2 kN / m or more and CD 0.1 kN / m or more. ~ 3. The coffee filter described in any of.
5. 1. The crepe paper is characterized in that the dissociation water content is 7 ° SR or more and 15 ° SR or less. ~ 4. The coffee filter described in any of.
6. Contains 80% or more of softwood pulp with respect to the total amount of pulp
A crepe paper in which the softwood pulp has an average lumen ratio of 0.50 or more and 0.70 or less.

Further, as a means for solving the problem of the present invention, the following other aspects can be mentioned.
7. It consists of crepe paper containing 80% or more of softwood pulp with respect to the total amount of pulp.
A coffee filter characterized in that 40% or more of the number of softwood pulp has a lumen ratio of 0.10 or more and 0.70 or less.
8. Contains 80% or more of softwood pulp with respect to the total amount of pulp
A crepe paper characterized in that 40% or more of the number of the softwood pulp has a lumen ratio of 0.10 or more and 0.70 or less.

The coffee filter of the present invention is mainly made of softwood pulp satisfying a specific lumen ratio, does not use hemp pulp whose supply is unstable, or suppresses the amount of hemp pulp used, so that it can be produced stably. can do.
The crepe paper used in the present invention has excellent drainage and wet strength, and can be suitably used as a coffee filter.

The figure which shows the coffee filter which is one Embodiment of this invention. Schematic diagram of pulp cross section.

1 Coffee filter 11 Top side 12 One side 13 Bottom 14 The other side

FIG. 1 shows a coffee filter 1 which is an embodiment of the present invention.
The coffee filter 1 according to one embodiment is a bag body having a substantially trapezoidal shape, and the upper side 11 is an opening. In the coffee filter 1, one sheet of crepe paper is bent, the bent side forms one side side 12, and the bottom side 13 and the other side side 14 are joined and closed. The upper side 11 is formed in an arc shape so that the opening becomes substantially circular when opened. The bottom side 13 and the other side side 14 are joined by press working without using an adhesive or the like so as not to adversely affect the flavor of coffee.

The coffee filter of the present invention is made of crepe paper containing 80% or more of softwood pulp with respect to the total amount of pulp, and the average rumen ratio of the softwood pulp is 0.50 or more and 0.70 or less. Here, in the present invention, the ratio of softwood pulp to the total amount of pulp can be calculated by dyeing the pulp, performing fiber analysis examined with an optical microscope, and discriminating the type of 100 or more pulps.

"Coniferous pulp"
FIG. 2 shows a schematic view of a cross section of pulp. What is generally called pulp is, to be correct, a temporary vessel in coniferous trees and a wood fiber in broad-leaved trees, and has a lumen called a lumen inside. The lumen ratio (l) is the ratio (l = b / d) of the lumen diameter (b) to the fiber diameter (d) of the pulp. The runkel ratio is also known as an index of the cross-sectional shape of the pulp, and the runkel ratio (R) is the ratio (R = 2a / b) of the fiber wall thickness (a) of the pulp to the lumen diameter (b). ..

The softwood pulp used in the present invention has an average lumen ratio of 0.50 or more and 0.70 or less. More preferably, the average lumen ratio is 0.50 or more and 0.65 or less.
Here, in general softwood pulp, the average lumen ratio is larger than 0.70 and 0.90 or less. For softwood pulp having an average lumen ratio of more than 0.70, it is difficult to produce a base paper having high drainage. The softwood pulp used in the present invention has a smaller lumen ratio than general softwood pulp. The softwood pulp having an average lumen ratio of 0.50 or more and 0.70 or less is rigid because the fiber wall is thick, and the pulp fibers are not easily crushed even when the wet paper is dried. Therefore, by blending this softwood pulp, it is possible to obtain a bulky and highly drainable base paper.

Here, in the present specification, the average of the lumen ratios of pulps is calculated from the average values obtained by measuring the fiber diameter, fiber wall thickness, and lumen diameter of 100 or more pulps by the following procedure.
1. 1. The pulp suspension in which the pulp is dispersed in water is diluted to a concentration of 0.05%. The pulp suspension can also be prepared by the same method as the raw material slurry used for the measurement of the dissociation water content described below.
2. 2. The diluted solution is dropped onto a clean preparation using a dropping tube, and if necessary, the fibers are uniformly dispersed using an anatomical needle.
3. 3. Place a cover glass to prevent air bubbles from entering, remove excess water with a piece of paper, and make a slide.
4. The slide is observed using an optical microscope, the slide is moved horizontally or vertically on a movable stage, and the fiber diameter (d), fiber wall thickness (a), and lumen diameter (b) of the pulp are measured.

The softwood pulp used in the present invention may have an average lumen ratio in the range of 0.50 or more and 0.70 or less, and may be mechanical pulp (MP), thermomechanical pulp (TMP), sulfite pulp (SP), or kraft. Pulp (KP), and one or more of these bleached pulp (BP) and unbleached pulp (UP) can be blended and used. Among the softwood pulps, kraft pulp (KP) and sulfite pulp (SP) are preferable because they have excellent wet strength and have little effect on the taste and flavor of the extracted coffee beverage.

"Other pulp"
The crepe paper used in the present invention may contain 80% or more of softwood pulp having an average lumen ratio of 0.50 or more and 0.70 or less, and is less than 20% as long as the characteristics required for the coffee filter are not impaired. Other pulps can be blended in the range. The blending amount of the softwood pulp having an average lumen ratio of 0.50 or more and 0.70 or less is preferably 85% or more, more preferably 90% or more, still more preferably 95% or more. Most preferably, it does not contain any other pulp.

Other pulp includes broad-leaved tree pulp, bast fibers such as flax, kenaf, 楮, and Mimata, hard fibers such as bagasse, bamboo, and esparto, seed hair fibers such as cotton linter, and leaf veins such as Manila hemp and sisal hemp. Non-wood pulp such as fiber can be used. In particular, by blending hemp pulp as other pulp, drainage and wet strength can be further improved. However, since hemp pulp is more expensive than softwood pulp, the blending amount of hemp pulp is preferably less than 10%, and it is most preferable that hemp pulp is not contained.

The pulp suspension used in the coffee filter of the present invention is preferably beaten so that the drainage degree (Canadian standard freeness: CSF) is 600 ml CSF or more and 700 ml CSF or less. By setting the degree of drainage within the above range, it is possible to produce crepe paper that satisfies the drainage required for the coffee filter.
The beating of the pulp suspension is not limited to the case of beating a suspension consisting only of softwood pulp, and even if the softwood pulp and other pulp are mixed and then mixed and beaten, the softwood pulp and the other pulp are separated. It may be mixed (separate beat) after beating. The drainage of other pulps in the case of separate beating is not particularly limited, but the drainage of the pulp suspension after mixing with the beaten softwood pulp in an arbitrary composition is 600 ml CSF or more and 700 ml CSF or less. It is preferable to adjust so as to be.

"Wet paper strength enhancer"
The coffee filter of the present invention preferably contains a wet paper strength enhancer. As the wet paper strength enhancer, polyamide polyamine epichlorohydrin resin, polyamine epichlorohydrin resin, (glyoxazar) modified polyacrylamide resin, urea formaldehyde resin, melamine formaldehyde resin, polyvinylamine resin, polyethyleneimine resin and the like can be used. Among them, polyamide polyamine epichlorohydrin resin is preferable.
The wet paper strength enhancer is preferably added in an amount of 0.1% by mass or more and 1.5% by mass or less, and 0.5% by mass or more and 1.0% by mass or less, based on the total pulp in the manufacturing process. It is more preferable to be added between.

The amount of the wet paper strength enhancer contained in the coffee filter can be quantified by elemental analysis by the Kjeldahl method, energy dispersive X-ray analysis, or the like. In the present invention, the amount of the wet paper strength enhancer contained in the coffee filter is a converted value when all the nitrogen elements quantified by the Kjeldahl method are derived from the polyamide polyamine epichlorohydrin resin. The coffee filter of the present invention preferably contains 0.05% by mass or more and 0.70% by mass or less of the wetting paper strength enhancer with respect to the total amount of pulp.

"Other additives"
In the coffee filter of the present invention, various additives can be used as needed as long as there are no problems with the voluntary standards for food paper, FDA approval, and the like.

"Crepe paper"
The coffee filter of the present invention is characterized by being crepe paper. The crepe paper has excellent drainage as compared with the base paper before crepe processing, and can be suitably used as a coffee filter. Further, since the crepe paper is easier to stretch than the base paper before the crepe processing, it is less likely to be torn during the press processing for joining the bottom side and one side of the coffee filter.

The method for producing crepe paper is not particularly limited, and the base paper is made from coniferous pulp and paper materials containing other pulps, wet paper strength enhancers, other additives, etc. as necessary, and the base paper is creped. By applying, it can be manufactured. The papermaking method is not particularly limited, and can be performed using a long net paper machine including a top wire, an on-top former, a gap former, a circular net paper machine, a short net paper machine, an inclined short net paper machine, and the like. The drying process can be appropriately selected from a multi-cylinder cylinder dryer, a Yankee dryer, a hot air dryer, and the like. Both the wet method and the dry method can be adopted for the crepe processing, but the wet method having a small difference between the front and back sides of the crepe shape is preferable.

The basis weight of the crepe paper is preferably 40 g / m ² or more and 70 g / m ² or less, and more preferably 50 g / m ² or more and 60 g / m ² or less. If the basis weight of the crepe paper is less than 40 g / m ² , the wettability may decrease, and when the coffee beverage is extracted, the fine powder of coffee beans may escape from the filter to the extract and cause an unpleasant taste. If the basis weight of the crepe paper is larger than 70 g / m ² , the drainage may decrease.
The thickness of the crepe paper is preferably 100 μm or more and 300 μm or less, more preferably 120 μm or more and 200 μm or less, and further preferably 130 μm or more and 180 μm or less. If the thickness of the crepe paper is thinner than 100 μm, it will not be stiff when used as a coffee filter, and may cause problems such as bending in the dripper when extracting coffee beverages. If the thickness of the crepe paper is thicker than 300 μm, the drainage may decrease.

The degree of disintegration water content of the crepe paper is preferably 7 ° SR or more and 15 ° SR or less. The crepe paper having the dissociation water content in the above numerical range has a drainage suitable for a coffee filter. In the present invention, the disintegration water content of the crepe paper is determined by immersing 30 g of the crepe paper in 500 ml of water, adding sodium hypochlorite having a solid content addition rate of 2% by mass to the paper, and treating the paper for 2 hours. , A value measured by the shopper-rigra method specified in JIS P8121-1 of a raw material slurry obtained by dissociating crepe paper sufficiently washed on a 200-mesh wire mesh by the method specified in JIS P8220-1.

The air permeability of the crepe paper is 2500 c. u. 3500c. u. The following is preferable. The crepe paper whose air permeability is in the above numerical range has a drainage suitable for a coffee filter. In the present invention, the air permeability is determined by using an air permeability meter PPM100 manufactured by FILTRONA in the United States, in an environment where the temperature is 23 ° C and the relative humidity is 50%, and the air flow per ^{1 cm 2} _under a pressure of 100 mmH2O. The value obtained by measuring the flow rate (ml / min).

The filtration time of the crepe paper (the time for 100 ml of water to pass through the paper using the Hertzberg filter degree tester measured according to JIS P3801 (1995)) is preferably 8 seconds or more and 20 seconds or less. .. If the filtering time is less than 8 seconds, the extraction cannot be sufficiently performed and the taste and flavor of the coffee beverage become light. Further, if the filtering time is longer than 20 seconds, the coffee beverage may overflow from above the filter being extracted depending on the type of coffee maker.

The wet tensile strength of the crepe paper is preferably such that the values measured according to JIS P8135 are MD 0.2 kN / m or more and CD 0.1 kN / m or more. Crepe paper whose wet tensile strength is within the above numerical range is easy to dispose of because it is not easily torn even if it is lifted while it is wet after coffee extraction and contains heavy coffee bean powder that has absorbed water. , Excellent in handleability.

The degree of crepe of the crepe paper can be evaluated by the breaking elongation of MD measured by JIS P8113. The MD breaking elongation of the crepe paper is preferably 5% or more and 15% or less. If the MD breaking elongation is less than 5%, the surface area cannot be increased and the drainage can not be improved as compared with that before the crepe processing, and the joint portion due to the press processing is cracked or torn, so that the joint cannot be formed. May occur. If the MD breaking elongation exceeds 15%, the drying efficiency in the papermaking process may decrease, and the punching processability into a substantially trapezoidal shape may decrease in the bag making process.

"Another aspect of coffee filter"
As another aspect of the coffee filter, it is made of crepe paper containing 80% or more of softwood pulp, and 40% or more, more preferably 50% or more of the number of the softwood pulp has a lumen ratio of 0.10 or more and 0.70 or less. A coffee filter, which is a softwood pulp of the above.
In the case of the coffee filter, which is another embodiment, the rumen ratio is calculated for 100 or more softwood pulps by the above method, and the rumen ratio to the total number of softwood pulps for which the rumen ratio is measured is 0.10 or more and 0.70 or less. The ratio (%) of the number of certain softwood pulps can be obtained. Further, the coffee filter according to another embodiment can be produced by the same method using the same softwood pulp, other pulp, wet paper strength enhancer, and other additives as the coffee filter according to the above-described embodiment. can. Further, it is preferable to satisfy the same characteristics as the coffee filter according to the above-described embodiment.

"Example 1"
Softwood pulp (NBKP, made in the United States, average ratio of rumen 0.60) was beaten with a refiner to CSF 647 ml and a beating degree of 17 ° SR. 0.75% by mass (solid content) was added to prepare a paper material.
Next, this paper material was made by a long net paper machine, and crepe processing was performed by a wet method to make crepe paper having a basis weight of 51.3 g / m ² .
"Example 2"
A crepe paper having a basis weight of 57.6 g / m ² was produced in the same manner as in Example 1 except that the same pulp as in Example 1 was beaten to a beating degree of CSF 662 ml and 15 ° SR.
"Example 3"
A crepe paper having a basis weight of 69.6 g / m ² was produced in the same manner as in Example 1 except that the same pulp as in Example 1 was beaten to a beating degree of CSF 681 ml and 11 ° SR.

"Example 4"
Using softwood pulp (NBKP, produced in the United States, average ratio of lumens: 0.68), CSF was 645 ml, and the beat was beaten to a beat of 17 ° SR, but the basis weight was 52.1 g / m ² in the same manner as in Example 1. The crepe paper was made.
"Example 5"
The paper material, which is a mixture of softwood pulp (NBKP, American, average ratio of rumen 0.68) and Manila hemp pulp from Ecuador at a ratio of 85:15 (mass%), is beaten, and the degree of beating is CSF 615 ml, 19 ° SR. A crepe paper having a basis weight of 53.3 g / m ² was obtained in the same manner as in Example 1 except that the paper was beaten up to.

"Comparative Example 1"
A crepe with a basis weight of 52.2 g / m ² in the same manner as in Example 1 except that softwood pulp (NBKP, produced in Canada, average ratio of lumens 0.74) was beaten to a beating degree of CSF 639 ml and 18 ° SR. I got the paper.

"Comparative Example 2"
An unprocessed paper having a basis weight of 52.4 g / m ² was obtained in the same manner as in Example 1 except that the crepe processing was not performed.

The physical characteristics of each of the crepe papers and unprocessed papers obtained above, as well as a coffee filter made of commercially available crepe paper as a reference example, were measured by the above method.
A substantially trapezoidal coffee filter was produced from each of the crepe papers and unprocessed papers obtained above. Each coffee filter and a commercially available coffee filter were set in the dripper, and the coffee beverage was extracted under the same conditions, and the drainage and the flavor of the coffee beverage at the time of extracting the coffee beverage were evaluated. In the unprocessed paper of Comparative Example 2, a hole was formed in the joint portion by press working, and a coffee filter could not be manufactured. Therefore, a coffee beverage was extracted by using a paper folded into a substantially trapezoidal shape.
The results are shown in Table 1.

Although the crepe paper of Examples 1 to 4 of the present invention is made of 100% softwood pulp, the crepe paper used in a commercially available coffee filter, that is, general softwood pulp (average of rumen ratio). 0.74) It has the same physical properties as crepe paper composed of 85% by mass and 15% by mass of hemp pulp, and in particular, its wet tensile strength is superior to that of commercially available products. In the crepe paper of Example 5 of the present invention, a better coffee filter could be obtained by blending hemp pulp with softwood pulp having an average lumen ratio of 0.68. Further, the coffee filter using the crepe paper of the example had good drainage, an appropriate drip time, and was able to brew a delicious coffee beverage having a flavor equivalent to that of a commercially available coffee filter.

On the other hand, the coffee filter using the crepe paper of Comparative Example 1 was manufactured from 100% general softwood pulp having an average lumen ratio of 0.74, so that the drainage was poor and the extract remained in the dripper. Therefore, the extraction time became long, and coffee beans powder and miscellaneous flavors were extracted, resulting in a coffee beverage with a lot of miscellaneous flavors. Further, the unprocessed paper of Comparative Example 2 had a small breaking elongation, so that a hole was formed in the joint portion by the press working, and the coffee filter could not be used. When the unprocessed paper of Comparative Example 2 was folded into a substantially trapezoidal shape and the coffee beverage was extracted using this as a coffee filter, the drainage was poor as in Comparative Example 1, and the extract was retained in the dripper, resulting in unpleasant taste. It became a lot of coffee drinks.

Claims (5)

It consists of crepe paper containing 80% or more of softwood pulp with respect to the total amount of pulp and having a filtration time of 8 seconds or more and 20 seconds or less .
A coffee filter in which the softwood pulp has an average lumen ratio of 0.50 or more and 0.70 or less. The coffee filter according to claim 1, wherein the wet paper strength enhancer is contained in an amount of 0.05% by mass or more and 0.70% by mass or less based on the total amount of pulp. The coffee filter according to claim 1 or 2 , wherein the crepe paper has a wet tensile strength of MD 0.2 kN / m or more and CD 0.1 kN / m or more. The coffee filter according to any one of claims 1 to 3 , wherein the crepe paper has a dissociation water content of 7 ° SR or more and 15 ° SR or less. Contains 80% or more of softwood pulp with respect to the total amount of pulp
The filtration time is 8 seconds or more and 20 seconds or less.
A crepe paper in which the softwood pulp has an average lumen ratio of 0.50 or more and 0.70 or less.

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