JP2000336570A - Biodegradable sheet material for coffee extraction - Google Patents

Abstract

(57) [Summary] [Problem] To be able to appropriately filter coffee fine particles, and to appropriately adsorb fats and oils to obtain a high-quality coffee extract, which is gradually decomposed in a natural environment. And
Provided is a sheet material for a coffee filter which does not lead to environmental destruction at the time of disposal after use. SOLUTION: It is made of polylactic acid, has an average fiber diameter of 20 µm or less, and has an air permeability of 10 to 250 cm ³ / cm ² ···.
A sheet material for coffee extraction comprising a melt blown ultrafine fiber nonwoven fabric having a water absorption rate of 5 seconds or less in water at a temperature of 60 ° C. or more for seconds.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a biodegradable sheet material for coffee extraction. More specifically, the present invention relates to a biodegradable coffee filter composite material useful for a coffee filter bag or a drip filter container for obtaining a high quality coffee extract.

[0002]

2. Description of the Related Art Conventionally, as a filter material for extracting coffee, a filter sheet made of paper or a filter sheet made of non-woven fabric has been generally used. Some of these conventional coffee extraction filter sheet materials are:
The effect of filtering and removing coffee particles (solids) is excessively high, so that the concentration and taste of the obtained coffee extract are thin,
Moreover, it is unsatisfactory, for example, it takes a long time for extraction, and in some cases, the effect of filtering and removing coffee particles (solids) is excessively low. Therefore, a large amount of solid coffee particles is contained in the obtained coffee extract. , The taste was poor, and a precipitate was formed.
Further, when the coffee fine powder is extracted with hot water, it is required that the fats and oils in the coffee fine powder be appropriately adsorbed and removed.

[0003] In order to obtain a high quality coffee extract, for example, Japanese Utility Model Laid-Open No. 55-129,667 discloses an 80 μm coffee extract.
A coffee bag formed using a filter sheet in which the distribution density of filtration pores having a size of m or more is limited to 6 pieces / cm ² or less is disclosed.
The use of a nonwoven fabric capable of preventing the transmission of particles having a relatively large particle size of at least μm was used, and was insufficient as a filter material for coffee fine particles. In addition, this coffee bag requires a pretreatment to separate and remove surface fine particles from the filled coffee fine particles in order to prevent leaching of the coffee fine particles,
There is a problem that the extraction component from the fine particles cannot be used and the extraction process becomes complicated, and it has not always been satisfactory to obtain a high quality coffee extract.

[0004] On the other hand, when disposing of fiber aggregates made of these synthetic resins as raw materials, these fiber aggregates are not decomposed if left in a natural environment, and are mainly incinerated or landfilled. However, in recent years, these disposal methods have a problem in that the progress of air pollution due to incineration of garbage or a shortage of landfills has been caused.

[0005]

DISCLOSURE OF THE INVENTION The present invention is suitable for obtaining a high quality coffee extract by extracting coffee fines at the time of coffee extraction and by adsorbing fats and oils appropriately. In a coffee filter sheet material, the sheet material gradually decomposes in the natural environment and eventually disappears, so that it does not lead to environmental destruction at the time of disposal after use, and has biodegradable coffee It is intended to provide a sheet material for a filter. Also,
An object of the present invention is to provide a sheet material for coffee extraction in which an oil agent for imparting hydrophilicity and improving spinnability is not added to the constituent fibers and coffee can be extracted without lowering the flavor of the coffee. .

[0006]

That is, the present invention comprises a biodegradable thermoplastic polymer, has an average fiber diameter of 20 μm or less, and has an air permeability of 10 to 250 cm ³ / cm ² ···.
A sheet material for coffee extraction comprising a melt-blown ultrafine fiber nonwoven fabric having a water absorption rate of 5 seconds or less in water at a temperature of 60 ° C. or more for seconds.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The sheet material of the present invention is composed of a thermoplastic resin having biodegradability, and a coffee filter using this sheet material, when coffee is extracted, does not reduce the flavor thereof, and provides high quality extraction. It is possible to obtain a liquid, it is gradually decomposed under natural environment after use,
There is no concern about air pollution due to incineration or environmental destruction due to neglect.

[0008] The kind of the thermoplastic resin is not particularly limited as long as it is a resin having biodegradability and predetermined hydrophilicity. Specifically, an aliphatic polyester resin is preferable, and examples thereof include polylactic acid, polybutylene succinate, polyethylene succinate, polybutylene succinate adipate, and poly-3-hydroxybutylene valerate. These may be used alone or in a blend.

The sheet material having hydrophilicity according to the present invention is obtained by the method of dropping water in the JIS L1096 general textile test method, wherein the dropped water is hot water, and the hot water is 60 ° C.
In the above case, it has hydrophilicity such that its water absorption rate is 5 seconds or less. A sheet material having a water absorption rate of more than 5 seconds is not preferable because it takes a long time to extract the coffee and is not only practical, but also lowers the temperature of the coffee extract during the extraction.

[0010] The extraction sheet material of the present invention is preferably a non-woven fabric produced by the melt blown method, which has a more uniform fiber distribution and density than other production methods, and thus has a uniform non-woven fabric. It has excellent filtration characteristics. The manufacturing method of the melt-blown microfiber non-woven fabric is based on Industrial and Engineering Chemistry.
istry), Vol. 48, No. 8, pp1342-1346, 1956. The sheet material is not particularly limited in thickness, basis weight, density, etc. as long as it has the predetermined extraction characteristics, but is preferably 5 to 70 g / m ² , more preferably 8 to 50 g / m ^2.
With a basis weight of Further, when the organic synthetic fiber has a large average diameter exceeding 20 μm, it is difficult to control the filtration characteristics of the obtained sheet material so as to satisfy the present invention, and the effect of removing fats and oils is insufficient. Become.

When a sheet material is produced by a melt blown method using polylactic acid as a biodegradable thermoplastic polymer having hydrophilicity, MFR (JIS K7210; 190 ° C., 2 ° C.)
It is preferable to use polylactic acid having a load of 160 g (under a load of 160 g) of 50 g / 10 minutes or more. With an MFR below this, it becomes very difficult to stably produce a targeted melt-blown nonwoven fabric with a small fiber diameter without decomposing the resin. When polybutylene succinate is used, it is preferable that its MFR (JIS K7210; 190 ° C, under a load of 2160 g) is 100 g / 10 minutes or more. This is because when a resin having a lower MFR value is used, it is extremely difficult to stably produce a melt-blown nonwoven fabric without decomposing the resin.

Further, in the sheet material for extraction of the present invention, if a single layer composed of a biodegradable meltblown ultrafine fiber layer is used, the required effect can be obtained.
If the sheet is likely to be damaged due to insufficient strength, such as when a large amount of coffee needs to be extracted at once, such as for business use, use a meltblown microfiber sheet as another strong support layer. It is preferable to combine and reinforce.

The support layer of the sheet material for coffee extraction according to the present invention comprises at least one material selected from porous materials such as woven or knitted fabric, mesh or net-like material, and non-woven fabric. It has a larger number of coarser pores and gives practically sufficient mechanical strength to the composite material of the present invention.

However, it is premised that the fibers forming the support layer also have biodegradability. In general, natural fibers (eg, cotton), regenerated fibers (rayon, cupra, etc.),
Alternatively, it can be selected from synthetic fibers using a biodegradable resin as a raw material (for example, polylactic acid, polyglycolic acid polyester, etc.). There is no particular limitation on the thickness of the single fiber of these fibers. Further, the fibers forming the support layer may be long fibers or short fibers.

It is preferable that the fibers in the support layer are partially fused and do not change their filtration performance during coffee extraction. For example, the fibers are produced by using a so-called spunbond method. It is preferable to use a spunbonded nonwoven fabric.

If the extraction sheet material is formed of a material other than the non-woven fabric, for example, a woven or knitted fabric, the coffee particles cannot be filtered sufficiently during the extraction and leak into the coffee extract. In addition, when the nonwoven fabric is formed of inorganic fibers, the nonwoven fabric cannot exhibit a proper removal effect on the oil and fat in the coffee extract.

In the sheet material for coffee extraction of the present invention, the lamination with the support layer can be carried out, for example, by bonding with a harmless adhesive, heat fusion, or mechanical entanglement. When using the heat fusion method, the support layer and the fiber filtration layer may be partially fused by at least one fusion region. In this fusion zone, at least one of the support layer and the fiber filtration layer has a portion of the fibers fused to the other layer, thereby binding the two layers. Further, the fiber filtration layer may have at least one fiber fusion zone. In this fiber fusion zone, a part of the aggregated and entangled microfibers is fused with the others, thereby preventing the movement or falling off of the microfibers during the coffee extraction operation, and also shrinking the fiber filtration layer, Alternatively, it is possible to prevent a dimensional change such as elongation, so that the filtering property of the sheet material for coffee filter of the present invention can be kept constant. There is no particular limitation on the number, shape, distribution state, and the like of the fusion zone of the two layers and the fiber fusion zone of the fiber filtration layer, and they can be appropriately set as long as the object of the present invention can be achieved.

Furthermore, the sheet material for coffee extraction of the present invention needs to have an air permeability of 10 to 250 cm ³ / cm ² · second. In addition, the air permeability referred to here indicates the air permeability of the composite sheet when the sheet material is composited by lamination or the like. Generally, a filter material, for example, a filter bag needs to have an appropriate liquid permeability (flux). If the liquid permeability is insufficient, it takes a long time to extract the coffee liquid, and such a filter material is not practical.
Also, an excessively large flux means that the filter material has a large number of large pores, so that the coffee fine particles are excessively transmitted through the filter material.

In the present invention, 10 to 250 cm ³ / cm ²
When coffee is extracted using a coffee bag made of a single or a composite sheet material having air permeability of seconds, the coffee powder is successfully steamed in the bag. That is, in the bag, the flavor component is easily extracted from the coffee powder.

The air permeability of the sheet material is 250 cm ³ / cm ²
If it is larger than seconds, the hot steam cannot stay in the bag for a sufficient time, and the steaming effect becomes insufficient. Also, the air permeability of the sheet material is 10 cm ³ /
When the time is shorter than cm ² · sec, the permeation of hot steam into the bag obtained is insufficient, and a sufficient steaming effect cannot be obtained. In order to obtain the above air permeability, the fiber filtration layer of the present invention preferably has a basis weight of 5 to 70 g / m ² as described above.

The sheet material for a coffee filter of the present invention can be formed into an appropriate shape and dimensions according to the purpose of use and conditions. For example, it may take any shape such as an extraction sheet, an extraction bag, an extraction cylinder, an extraction funnel, and the like.

In particular, when producing a coffee filter sheet or a coffee filter bag from the sheet material of the present invention, the sheet material (fiber filtration layer) may be arranged on the primary side of filtration (coffee powder side), It may be arranged on the next side (coffee filtrate side). When the fiber filtration layer is disposed on the primary filtration side, the filtration pores are blocked by the coffee fine particles, so that the coffee particles can be appropriately steamed on the primary filtration side. In the case of a coffee filter bag, if the support layer is disposed on the secondary side of the filtration, the hot water easily permeates into the bag, thereby facilitating the extraction operation. In addition, the fiber filtration layer disposed on the primary side of the filtration exhibits an appropriate adsorption and trapping effect on the oil and fat in the extract, and the resulting aesthetic appearance of the coffee liquid is impaired by the floating of the oil and fat. Can be prevented, and the taste and the taste can be adjusted appropriately.

Further, it is important that the sheet material of the present invention has biodegradability. Since this sheet has biodegradability, both the coffee particles and the filter after extraction are naturally decomposed, thereby preventing dust from being deposited later. On the other hand, coffee beans contain many nutrients, and the coffee particles after use are also useful as fertilizers.
Therefore, if the sheet material of the present invention is used, there is no contamination by the hydrophilic agent, no need for an operation of separating the filter from the coffee particles, and the filter material after use is composted together with the coffee particles in a compost to effectively utilize the filter material. it can.

[0024]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.
In addition, the air permeability was determined using the Frazier method of JIS L-1096 General Textile Test Method.

Example 1 and Comparative Example 1 MFR (230 ° C., 2160 g load) was 190 g / 10
Using a polylactic acid resin having a mixing ratio of D-form of 23.9% at 280 ° C. and a single hole discharge rate of 0.4 g / min.
A melt blown nonwoven fabric comprising polylactic acid ultrafine fibers having an average diameter of 10 μm and a basis weight of 50 g / m ² was produced. Then, for the purpose of stabilizing the form and maintaining the strength of the nonwoven fabric, the constituent fibers of the nonwoven fabric were partially heat-sealed in a hot embossing step to produce a sheet material. At this time, the crimping area was 15%. The air permeability of this sheet material was about 36 cm ³ / cm ² · second, and the water absorption rate when hot water at 80 ° C. was used was 0.2 seconds. Next, a drip coffee filter (a bag-like body having an opening at one end) was prepared from the sheet material. The roasted coffee beans were pulverized and, without sorting the particles, 15 g thereof were filled in the coffee filter, 150 ml of distilled water at a temperature of 90 ° C. was poured from the upper opening, and coffee powder was extracted and filtered. The time required for extraction filtration was about 90 seconds.

The obtained coffee liquid had a suitable degree of transparency and was of high quality with excellent aroma and taste. For comparison, coffee was extracted using commercially available pulp paper for coffee drip (air permeability = 7 cm ³ / cm ² · second) in the same manner as in the example. The required extraction and filtration time was 180 seconds, and the weight of solids in the obtained coffee extract was 1.86.
g. The maximum particle size of the fine particles in the small particle size fine particle fraction occupying 50% of the total volume of the coffee fine particles transmitted through the filter was about 4 μm. The obtained coffee liquor was lighter in color tone and inferior in both aroma and taste compared to the coffee liquor of Example 1.

Example 2 The polylactic acid resin used in Example 1 was discharged at a single hole discharge rate of 0.2 g.
A melt-blown nonwoven fabric made of polylactic acid ultra-fine fibers having an average diameter of about 4 μm and a spunbonded nonwoven fabric also made of polylactic acid as a raw material are produced by the same method as in Example 1, except that the two layers are formed. Partially heat-sealed to obtain a composite nonwoven fabric. The air permeability of this composite nonwoven fabric is 200 cm
³ / cm ² · sec, and the water absorption rate when hot water at 80 ° C. was used was 0.5 sec. Using this nonwoven fabric, a bag for a coffee bag was produced. The maximum particle size of the fine particles in the small particle size fine particle fraction occupying 50% of the total volume of the coffee fine particles passed through the filter bag was about 10 μm.

Example 3 MFR (190 ° C., 2160 g load) is 330 g / 10
Using a polybutylene succinate resin,
Under the conditions of ° C and a single hole discharge rate of 0.3 g / min / hole, a melt-blown nonwoven fabric made of polybutylene succinate ultra-fine fibers having an average diameter of about 6 µm and a spunbonded nonwoven fabric made of the same polybutylene succinate fiber are laminated. Both layers were partially heat-sealed to obtain a composite nonwoven fabric. The air permeability of this composite nonwoven fabric is about 25 cm ³ / cm ² · sec.
Was 0.5 seconds when hot water was used. Using this nonwoven fabric, a bag for a coffee bag was produced.
8 g of the finely ground roasted coffee powder was filled in the above-mentioned bag-like material and sealed to obtain a coffee bag. Put the above coffee bag and 150 ml of hot water at a temperature of 95 ° C in a container,
The bag was shaken in the water for 90 seconds. Observation of the obtained coffee liquid showed that there was no precipitation of fine particles or floating of oils and fats, and it was a high-quality coffee liquid having an appropriate concentration and aroma.

Comparative Example 2 M containing 0.5% by weight of an amide type surfactant was kneaded.
Using a polypropylene resin having an FR (230 ° C., 2160 g load) of 30 g / 10 min, 265 ° C., a single hole discharge amount of 0.1 g / m.
Under the conditions of 3 g / min / pore, a melt blown nonwoven fabric made of fibers having an average diameter of 30 μm was produced. This nonwoven is 27
It had an air permeability of 0 cm ³ / cm ² · second, and the water absorption rate when using hot water at 80 ° C. was 15 seconds. Using this, a coffee bag was made in the same manner as in Example 1,
A coffee liquid was prepared. The coffee liquor had a concentration similar to that of the coffee liquor according to the present invention, but was a low-quality coffee liquor, with fats and oils floating on the liquid surface and a large amount of precipitated fine particles observed at the bottom of the container. The amount of the precipitated fine particles is 3.5 m.
g and its particle size was widely distributed in the range of 50-100 μm.

The nonwoven fabrics of Examples 1 to 3 and the nonwoven fabric of Comparative Example 2 were embedded in an aged compost maintained at about 50 ° C., and the nonwoven fabrics were observed three months later. Although the shape was almost retained, the nonwoven fabrics of Examples 1 to 3 did not retain the shape and were almost decomposed.

[0031]

The sheet material for coffee extraction of the present invention is
Particularly useful as a coffee filter bag, or drip coffee filter material, it can be extracted at an appropriate extraction rate, and permeates coffee fines appropriately,
In addition, the oil and fat can be appropriately adsorbed and collected. Furthermore, since the constituent fibers are hydrophilic, there is no contamination of the coffee extract by the fiber oil agent, and a moderate density,
It makes it possible to prepare a high-quality coffee liquid having a favorable flavor in a short time by a simple operation, and after use, biodegrades and disappears in a natural environment.

Claims (4)

[Claims] 1. A biodegradable thermoplastic polymer comprising:
It has an average fiber diameter of 0 μm or less and an air permeability of 10 to 250
A sheet material for coffee extraction, comprising a melt blown ultrafine fiber nonwoven fabric having a water absorption rate of 5 seconds or less in water at a temperature of 60 ° C. or more at cm ³ / cm ² · second. 2. The sheet material for coffee extraction according to claim 1, which is supported on a biodegradable support layer. 3. A coffee filter sheet comprising the sheet material according to claim 1. 4. A coffee filter bag comprising the sheet material according to claim 1.