JP3137213B2 - Extraction filter material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extraction filter material having good heat bonding workability which is useful for extraction bags, extraction bags and the like of green tea, black tea, coffee and the like.

[0002]

2. Description of the Related Art In recent years, the use of extraction bags has been expanding, and the development of high-speed filling and packaging machines has been progressing in order to improve productivity at production sites. Accordingly, there is a demand for an extraction filter material suitable for a high-speed filling and packaging machine. Conventional filter materials include short-fiber nonwoven fabric, long-fiber nonwoven fabric, and paper.The short-fiber nonwoven fabric has a heat-adhesive property by adding a heat-adhesive or a heat-adhesive fiber such as polypropylene or polyethylene to cellulosic fibers. Nonwoven fabric is used, and the same is used for paper. Polyethylene by spun bond method as long fiber nonwoven fabric,
A nonwoven fabric of polypropylene is used. Further, in order to suppress leakage of particles after extraction, a nonwoven fabric obtained by laminating ultrafine fiber nonwoven fabrics is used. However, when using a high-speed filling and packaging machine, increasing the heat sealing speed requires increasing the set temperature. In this case, the pressure-bonded surface of the heat sealer becomes stained with resin, resulting in poor adhesion or shrinkage, reducing the commercial value. Is lowering. In addition, the temperature of the heat seal portion is too high due to the ability to control the set value of the temperature of the heat seal portion.

[0003]

The extraction filter material of the prior art is contaminated by the change in temperature of the heat-sealed portion.
Poor adhesion, shrinkage, etc. often occurred. In view of such circumstances, the present invention reduces the occurrence of contamination, poor adhesion, and shrinkage of the press-bonded surface due to a change in the temperature of the heat sealing portion of a high-speed filling and packaging machine, and reduces the occurrence of shrinkage. The purpose is to provide.

[0004]

The inventor of the present invention has conducted intensive studies on filter materials in order to obtain good heat-sealing properties with respect to temperature changes in the heat-sealing portion of a high-speed filling and packaging machine. Solves the problem of heat sealing of high-speed filling and packaging machines by laminating a microfiber nonwoven fabric with a melting point considerably higher than the fusion temperature of the heat bonding fiber and arranging and bonding the microfiber nonwoven fabric so as to be in contact with the heat sealing surface. I have to do it. That is, the present invention relates to a heat-bondable nonwoven fabric containing heat- fusible fibers and a heat- bondable nonwoven fabric having an average fiber diameter of 10 μm or less.
A laminate with a microfiber nonwoven fabric made of plastic fibers ,
The fusion temperature of the heat fusion fiber is 110-170 ° C ,
Is an extraction filter material having a melting point of 80 ° C. or more higher than the fusion temperature of the thermally fusible fibers and having good heat bonding processability.

Hereinafter, the present invention will be described in detail. The extraction filter material of the present invention is composed of a nonwoven fabric containing heat-fusible fibers and microfibers made of thermoplastic fibers. The non-woven fabric containing the heat-fusible fiber may be any of a short-fiber non-woven fabric and a long-fiber non-woven fabric.
Any material, such as polypropylene, polyester, and polyamide, may be used as long as it has an appropriate adhesive strength. The heat-fused fiber is a conjugate fiber having a core-sheath structure or a parallel-type structure, and has a melting point of 50% higher than that of the heat-fused fiber on one side of the core portion of the core-sheath structure or one side of the parallel-type structure in order to suppress heat shrinkage during heat sealing. It is preferable to use a fiber having a temperature of 70 ° C. or higher, preferably 70 ° C. or higher.
In the nonwoven fabric containing heat-fusible fibers, thermoplastic fibers and cellulosic fibers other than heat-fusible fibers, such as polyester, polyamide, cupra, rayon, and the like can be mixed.
The melting point of this fiber is 50 ° C. or more, preferably 70 ° C. or more, higher than the fusion temperature of the heat-fused fiber. If the temperature is lower than 50 ° C., it is not preferable because it tends to cause shrinkage during heat sealing. The reason for blending thermoplastic fibers and cellulosic fibers into the nonwoven fabric containing heat-fusible fibers is to minimize the contamination of the crimping part of the heat sealing machine by the heat-sealing fibers during fusion. Fiber or long fiber may be used. The blending ratio (% by weight) of the thermoplastic fiber and / or the cellulosic fiber blended with the heat fusion fiber is 90:10 to 10:10.
The ratio is 50:50, and the optimum blending ratio is determined by the basis weight of the laminated ultrafine fiber nonwoven fabric. If the blending ratio is less than 90:10, no improvement in the contamination of the pressure-bonded portion of the heat sealing machine is observed, and if it is greater than 50:50, the adhesive strength decreases, which is not good.

The ultrafine fibers made of thermoplastic fibers may be those produced by a composite spinning method or a melt blow method, but those obtained by the melt blow method are preferred in terms of productivity and cost, and the fiber diameter is 10 μm or less, preferably 5 μm or less. It is. If the fiber diameter is larger than 10 μm, the heat-sealing surface of the heat-sealing machine is stained by the heat-sealing resin during heat-sealing, and the particles in the extract after extraction are undesirably large. The basis weight of the microfiber nonwoven fabric is preferably 5 to ²⁰ g / m ² , and more preferably 7 to ²⁰ g / m ^2.
15 g / m ² . If the basis weight is less than 5 g / m ² , the heat-bonding portion of the heat-sealing machine tends to adhere to the heat-adhesive resin and the leakage of particles during extraction is undesirably increased. If the basis weight is more than 20 g / m ² , the extraction speed is undesirably slow.

[0007] An extraction filter material suitable for a high-speed filling and packaging machine provides a stable bond with respect to a change in the heat sealing temperature. It is desired not to contaminate the crimp surface.
The extraction filter material of the present invention has a temperature difference between the fusion temperature of the heat-fused fibers and the melting point of the ultrafine fibers in contact with the heater surface of 80.
C. or higher, so that even if the fused fiber resin melts, it stays in the ultrafine fiber nonwoven fabric and does not stain the heater surface. Further, since the melting point of the ultrafine fibers of the ultrafine fiber nonwoven fabric is set to be considerably higher than the fusion temperature of the heat fusion fibers, the heater surface is not stained or fused.

[0008]

The present invention will be further described with reference to the following examples. The dry heat shrinkage S in the examples was measured by the following operation. Dry heat shrinkage (%) A mark representing the length of exactly 10 cm is placed at each of the three positions in the vertical and horizontal directions of the sample. When the temperature of the thermostat dryer is set to 160 ° C. and the set temperature is reached, the sample is put in, left for 10 minutes, taken out, and cooled to room temperature. After that, measure the length of each of three places in the vertical and horizontal directions,
To determine the dry heat shrinkage.

[0009]

(Equation 1)

Here, S: dry heat shrinkage (%), L: total length of three lines before treatment (mm), L ': total length of three lines after treatment (mm)

Examples 1, 2, 3 and Comparative Examples 1, 2, 3 A basis weight 1 made of a heat-sealed fiber having a core-sheath structure in which the sheath component is polyethylene and the core component is polyethylene terephthalate.
A 5 g / m ² fiber non-woven fabric and an ultra-fine fiber non-woven fabric made of polyethylene terephthalate having an average fiber diameter of 3.5 μm and a basis weight of 15 g / m ² were laminated and then partially fused to obtain an extraction filter material of Example 1. A short-fiber nonwoven fabric with a core weight of 15 g / m ² , made of a core-sheath structure heat-fused fiber with a sheath component made of polypropylene and a core component made of polyethylene terephthalate, and a microfiber made of polyethylene terephthalate with a fiber weight of 15 g / m ² with an average fiber diameter of 3.5 μm The nonwoven fabric was laminated and partially fused to obtain an extraction filter material of Example 2. A nonwoven fabric with a basis weight of 15 g / m ² made by blending a single fiber made of a heat-sealed fiber having a core-sheath structure composed of polyethylene as the sheath component and polyethylene terephthalate and a short polyethylene terephthalate fiber at a ratio of 80:20. An ultra-fine fiber non-woven fabric made of polyethylene terephthalate having an average fiber diameter of 3.8 μm and a basis weight of 5 g / m ² was laminated and then partially fused to obtain an extraction filter material of Example 3. 1. A short-fiber nonwoven fabric made of a heat-sealed fiber having a core-sheath structure in which the sheath component is made of polyethylene and the core component is made of polyethylene terephthalate;
The basis weight 15 g / m ² of microfibrous non-woven fabric made of polypropylene was laminated after partial fusing obtain an extract filter material of Comparative Example 1 in 9 .mu.m. A short-fiber non-woven fabric made of a heat-sealed fiber having a core-sheath structure in which the sheath component is made of polyethylene and the core component is made of polyethylene terephthalate is partially melted after laminating an ultra-fine fiber non-woven fabric made of polyethylene terephthalate having an average fiber diameter of 3.8 μm and a basis weight of 5 g / m ^2. Thus, an extraction filter material of Comparative Example 2 was obtained. Further, a short fiber non-woven fabric made of a heat-sealed fiber having a core-sheath structure in which the sheath component was made of polyethylene and the core component was made of polypropylene was used as the extraction filter material of Comparative Example 3.
Using the heat-sealing machine, set the set temperature of the extraction filter material obtained as described above to 30 ° C. higher than the fusion-bonding temperature of the heat-bonded fiber, heat-seal 500 pieces, and visually check the heat-sealed surface for contamination with resin. Was evaluated. The visual evaluation criteria are as follows. Visual evaluation Grade 1: No contamination confirmed Grade 2: Slightly dirty Grade 3: Very dirty Grade 4: Very dirty Evaluation results are shown in Table 1.

[0012]

[Table 1]

In Table 1, (PE / PET), (PP / PET)
(PET), (PE / PP), PET and PP indicate the following contents. (PE / PET): Core-sheath type composite fiber of core component polyethylene terephthalate, sheath component polyethylene (PP / PET): Core-sheath type composite fiber of core component polyethylene terephthalate, sheath component polypropylene (PE / PP): core component polypropylene, Core-sheath type composite fiber of sheath component polyethylene PET: polyethylene terephthalate PP: polypropylene It can be seen from Table 1 that the extraction filter material of the present invention is excellent in heat sealability.

[0014]

The extraction filter material of the present invention suppresses the occurrence of dirt, poor adhesion and shrinkage on the press-bonded surface due to a change in the temperature of the heat-sealing portion, has good heat-sealing properties, and has an excellent extraction function.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI D04H 3/00 D04H 3/00 JK 3/14 3/14 A

Claims (3)

(57) [Claims] 1. A non-woven fabric containing heat-fused fibers and an average fiber diameter of 10
A laminate with a microfiber nonwoven fabric made of thermoplastic fiber having a size of not more than 1 μm, wherein the fusion temperature of the heat-fusible fiber is 110 to 1
An extraction filter material that has a melting point of ultrafine fibers at 70 ° C. higher than the fusion temperature of the heat-fused fibers by 80 ° C. or more, and has good heat bonding workability. 2. The non-woven fabric containing the heat-fusible fiber,
A conjugate short fiber (A) in which the heat-fused fiber and the thermoplastic fiber are a core-sheath type or a side-by-side type, and a short fiber (B) composed of at least one kind of a thermoplastic fiber and / or a cellulosic fiber.
And a weight ratio of A: B = 90: 1.
The extraction filter material according to claim 1, wherein the ratio is from 0 to 50:50. 3. The ultra-fine fiber nonwoven fabric, wherein the ultra-fine fibers are polyethylene terephthalate and have a dry heat shrinkage of 10
% Of the extraction filter material according to claim 1.