Granular material for fibers

Abstract

This invention relates to granular material for textiles obtained by recycling raw materials including waste, which has high deodorizing properties against excrement odor, textile products containing the same, and a method for producing granular material for textiles. [Solution] A granular material for fibers according to one embodiment of the present invention is a granular material for fibers which is a heat-treated product of raw materials including waste, and has a surface including irregularities and openings formed on the surface. The maximum size of the openings is 1 μm or more and 17 μm or less. The porosity of the surface is 10% or less. The granular material for fibers has deodorizing properties.

Description

Technical Field

[0001] The present invention relates to granular materials for fibers obtained by recycling raw materials containing waste such as absorbent articles.

Background Art

[0002] From the viewpoints of reducing emissions of greenhouse gases and realizing a recycling-based society, technologies for recycling waste to produce functional articles have been studied. For example, Patent Document 1 describes a technology for carbonizing used sanitary articles at 310 to 450°C and recycling the generated carbide as a deodorant or the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, Patent Document 1 does not describe using carbide for fibers. Also, although Patent Document 1 describes that acetic acid odor and ammonia odor are reduced, the amount of carbide used in the test is not described, and tests for excretory odors other than acetic acid odor and ammonia odor have not been conducted.

[0005] The present invention relates to granular materials for fibers obtained by recycling raw materials containing waste and having high deodorizing properties against excretory odors, fiber products containing the same, and a method for producing the granular materials for fibers.

Means for Solving the Problems

[0006] The granular material for fibers according to one embodiment of the present invention is a granular material for fibers that is a heat-treated product of a raw material containing waste, having a surface including irregularities and apertures formed in the surface. The maximum size of the opening is between 1 μm and 17 μm. The porosity of the surface is 10% or less. The aforementioned granular material for fibers has deodorizing properties.

[0007] Another embodiment of the present invention relates to a method for producing granular fiber materials using waste, The process includes a step of stirring the raw materials, including waste, while heating them to a temperature between 180°C and 300°C. The aforementioned granular material for fibers is, It has a surface that includes irregularities and openings formed on the surface. The maximum size of the opening is between 1 μm and 17 μm. The porosity of the surface is 10% or less. The aforementioned granular material for fibers has deodorizing properties. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide granular material for textiles that can be obtained by recycling raw materials including waste and has high deodorizing properties against excrement odor, textile products containing the same, and a method for producing granular material for textiles. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing an apparatus that can be used for a method of producing granular material for fibers according to one embodiment of the present invention. [Figure 2] This flowchart shows the method for producing the above-mentioned granular material for fiber. [Figure 3] The above figure shows the granular material for fibers, and the image shows the granular material for fibers according to an embodiment of the present invention, magnified and captured with a scanning electron microscope. [Figure 4] This diagram illustrates the method for calculating the porosity on the surface of the granular fiber material described above. It shows the surface of the granular fiber material and the outline of the pores enclosed by thick lines, as shown in the image in Figure 3. [Figure 5] This is a schematic diagram showing an apparatus that can be used in a method for producing granular materials for fibers according to another embodiment of the present invention. [Figure 6] This graph shows the test results in an embodiment of the present invention, illustrating the reduction rate of odor components in excrement odor when different amounts of granular fiber material are in contact with the material for 2 hours. The horizontal axis represents the amount of granular fiber material, and the vertical axis represents the reduction rate of odor components. [Figure 7] (A) to (D) show images of the surface of the paper produced in the embodiment of the present invention, magnified and captured with a scanning electron microscope. (A) shows paper made only of pulp fibers, (B) shows paper containing 10% by mass of fiber granules, (C) shows paper containing 20% ​​by mass of fiber granules, and (D) shows paper containing 30% by mass of fiber granules. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below.

[0011] [Substance Description of Embodiments of the Invention] The granular material for fibers according to one embodiment of the present invention is a heat-treated material containing waste. This granular material for fibers has a different composition from conventionally known carbonized materials with deodorizing properties such as activated carbon, and has high deodorizing properties against excrement odor.

[0012] The waste used in one embodiment of the present invention includes, for example, all types of waste generated from households and businesses. From the viewpoint of increasing carbonization efficiency and obtaining sufficient deodorizing properties, it is preferable that the waste includes combustible waste. Combustible waste as used herein refers to waste mainly containing organic matter classified as combustible waste, and examples include food waste, paper, cloth, resin products, plants, wood products, rubber products, leather products, and mixtures thereof. Thus, combustible waste may include cellulose such as paper, some types of cloth, plants, and wood products. From the viewpoint of increasing the carbonization ratio of the resulting granular material, the content of combustible waste in the above waste is preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 50% by mass.

[0013] Further, the combustible waste used in one embodiment of the present invention preferably contains a thermoplastic resin. Examples of the waste containing a thermoplastic resin include used packaging containers (such as food containers and bottles), used absorbent articles (such as paper diapers and sanitary napkins), and marine garbage. Among these, the waste preferably includes used absorbent articles that are discharged due to childcare and nursing care and may pose a problem in terms of treatment. The thermoplastic resin contained in the waste is not limited to a specific type, and examples include polyolefin, polyester, polyacrylic acid, sodium polyacrylate (superabsorbent polymer), and the like. Further, the waste may contain two or more thermoplastic resins.

[0014] Also, the combustible waste used in one embodiment of the present invention may be, for example, non-infectious waste or infectious waste discharged from medical-related institutions and the like. Examples of the medical-related institutions and the like that are the discharge sources include hospitals, clinics, sanitary inspection offices, nursing care facilities for the elderly, nursing care hospitals, maternity hospitals, and the like. The above infectious waste includes waste containing pathogens that can infect humans or have the potential to infect, waste to which such pathogens are attached, and waste that may fall under these categories. Specifically, in addition to used absorbent articles used by patients with infectious gastroenteritis and the like, disposable products such as syringes to which blood or body fluids are attached are included. Non-infectious waste corresponds to waste other than infectious waste (for example, combustible waste), and examples include papers, food waste, non-infectious bandages, absorbent cotton, gloves, surgical masks, aprons, general used absorbent articles, and other plastic products.

[0015] In one embodiment of the present invention, "granular" refers to a shape like fine grains, and "granular body" refers to an aggregate of mutually separated granular fragments. The particle size of the granular body for fibers is preferably 10 μm or more, more preferably 30 μm or more, preferably 5 cm or less, more preferably 1 cm or less, and even more preferably 0.5 cm or less. Note that the particle size of the granular body is the maximum diameter of each fragment constituting the granular body. The detailed configuration of the granular body will be described later.

[0016] [Manufacturing equipment (processing device) for granular materials for fiber] First, with reference to Figure 1, a processing apparatus 100 usable in a method for producing granular material according to one embodiment of the present invention will be described. The processing apparatus 100 comprises a processing tank 101, a first heating unit 110, a second heating unit 120, and a control unit 130. The processing apparatus 100 is configured, for example, as a batch-type carbonization apparatus. The processing apparatus 100 may also further include an exhaust gas processing unit for exhaust gas treatment, although this is not shown in the figures.

[0017] The processing tank 101 has a wall section 101a and a storage section 101b. The storage section 101b is capable of accommodating the raw materials to be processed by the processing apparatus 100 and is configured as an internal space of the processing tank 101 surrounded by the wall section 101a. Figure 1 shows the interior of the storage section 101b by displaying a vertical cross-section obtained by vertically cutting the wall section 101a. In the processing tank 101, a part of the wall section 101a is configured to be openable and closable as an input port for raw materials.

[0018] The processing tank 101 further includes one or more stirring shafts 102. Each stirring shaft 102 has a shaft portion 102a and a plurality of blade portions 102b. The shaft portion 102a is configured as a rod-shaped member that can rotate around a rotation axis C extending horizontally to the side. Both ends of the shaft portion 102a are supported by the wall portion 101a on the side of the housing portion 101b, and the portion between the ends supported by the wall portion 101a is located inside the housing portion 101b. The plurality of blade portions 102b are provided at intervals along the longitudinal direction. Each blade portion 102b also protrudes from the outer circumferential surface of the shaft portion 102a in various radial directions.

[0019] From the viewpoint of improving the efficiency of stirring, the processing tank 101 preferably has a plurality of stirring shafts 102. These stirring shafts 102 are preferably arranged such that their shaft portions 102a are substantially parallel to each other, for example, along a horizontal direction perpendicular to the vertical direction.

[0020] The first heating unit 110 heats the wall portion 101a of the processing tank 101. In other words, the first heating unit 110 has the function of heating the containment portion 101b from the outside. In this embodiment, the first heating unit 110 has a heater 111 that heats the wall portion 101a. The heating method of the heater 111 is not limited, but from the viewpoint of facilitating temperature control, an electric heater is preferred. The various configurations of the heater 111, such as the installation position, can be determined in various ways depending on the configuration of the processing tank 101 and the properties of the raw materials. For example, in Figure 1, the heater 111 is located at the bottom of the wall portion 101a, but it may also be located to the side or above the wall portion 101a.

[0021] The second heating unit 120 supplies heated gas to the containment section 101b. In other words, the second heating unit 120 has the function of directly heating the inside of the containment section 101b with hot air. In this embodiment, the second heating unit 120 has an air supply section 121, an exhaust section 122, a blower section 123, and a heating section 124. In this embodiment, the second heating unit 120 is a hot air circulating heating unit that heats the gas exhausted from the containment section 101b and supplies it to the containment section 101b by operating the blower section 123. By supplying the circulated gas to the containment section 101b, waste heat can be recovered and energy efficiency can be improved. The gas used in the second heating unit 120 is not particularly limited and may be air or an inert gas such as nitrogen.

[0022] The air supply unit 121 supplies gas to the containment unit 101b. In this embodiment, the air supply unit 121 is configured as a gas passage connecting the containment unit 101b and the blower unit 123 (heating unit 124). The air supply unit 121 is composed of one or more tubular members, including, for example, a tubular member provided to penetrate the wall portion 101a of the processing tank 101.

[0023] The exhaust section 122 exhausts gas from the containment section 101b. In this embodiment, the exhaust section 122 is configured as a gas passage connecting the blower section 123 and the containment section 101b. The exhaust section 122 is composed of one or more tubular members, including, for example, a tubular member provided to penetrate the wall section 101a of the processing tank 101. From the viewpoint of efficiently circulating the gas, it is preferable that the exhaust section 122 is positioned in the wall section 101a so as to face the supply air section 121 with the containment section 101b in between.

[0024] The air blower 123 blows gas to the air supply 121. The air blower 123 is composed of a blower such as a fan, blower, or compressor. The air blower 123 is positioned between the air supply 121 and the exhaust 122.

[0025] The heating unit 124 heats the gas supplied to the containment unit 101b. The heating unit 124 may be located on the exhaust side of the air blower unit 123 or on the supply side, as shown in Figure 1. Also, the heating unit 124 may be connected to the air blower unit 123 or located at a distance from it, as shown in Figure 1. The heating unit 124 consists of a heater that heats the gas, and from the viewpoint of facilitating temperature control, it is preferable that it consists of an electric heater. The heating method and installation position of the heater constituting the heating unit 124 can be determined in various ways depending on the configuration of the processing tank 101 and the properties of the raw materials.

[0026] Furthermore, the second heating unit 120 may, if necessary, have components (e.g., dampers, valves, etc.) to adjust the flow rate of gas supplied to the housing section 101b, and valve components that allow for the intake and exhaust of outside air. In addition, an exhaust processing unit may be connected to the exhaust passage branching off from the second heating unit 120.

[0027] The control unit 130 is configured as a processor that controls each part of the processing unit 100, and specifically includes a CPU (Central Processing Unit) and an MPU (Micro-Processing Unit), etc. Furthermore, the processing unit 100 may have an operation panel connected to the control unit 130 that allows user input operations (not shown).

[0028] In the processing apparatus 100 with the above configuration, the temperature inside the containment section 101b can be made uniform by the two heating units, the first heating unit 110 and the second heating unit 120, and the temperature inside the containment section 101b can be controlled with high precision. Furthermore, by using the processing apparatus 100 in the following manufacturing method, the material to be processed can be stirred while controlling the heating temperature to the temperature range described later, and a granular material for fibers having the desired configuration and function can be manufactured.

[0029] [Method for manufacturing granular materials for fiber] A method for producing granular material for fibers according to one embodiment of the present invention includes a preparation step S01, a heating and stirring step S02, and a cooling step S03, as shown in Figure 2.

[0030] Preparation step S01 involves preparing raw materials, including waste. The raw materials may include the aforementioned waste and other raw materials.

[0031] In the heating and stirring step S02, the raw material containing waste is heated and stirred to a temperature of 180°C to 300°C. By heating the material to a temperature of 180°C to 300°C, the material can be slowly carbonized while undergoing thermal decomposition, thereby producing granular fiber material with the configuration described later. The heating temperature in this step only needs to have a maximum temperature of 180°C to 300°C, and may be maintained at the maximum temperature or fluctuate within the above temperature range. The time for maintaining a temperature of 180°C to 300°C is preferably 1 hour or more, more preferably 2 hours or more, preferably 5 hours or less, and more preferably 4 hours or less, from the viewpoint of allowing carbonization to proceed slowly and forming surface irregularities and pores.

[0032] In this step, raw materials are placed in the containment section 101b of the processing apparatus 100 as illustrated in Figure 1, and the processing apparatus 100 is operated. In this case, the heater 111 of the first heating unit 110 heats the wall section 101a, thereby heating the containment section 101b from the outside. Furthermore, in the second heating unit 120, by operating the blower section 123 and the heating section 124, gas is exhausted from the containment section 101b by the exhaust section 122, the exhausted gas is heated by the heating section 124, and the heated gas is supplied to the containment section 101b from the air supply section 121. As a result, the inside of the containment section 101b can be directly heated by the heated gas (hot air), the containment section 101b can be heated efficiently, and the rate of heating can be easily controlled.

[0033] Furthermore, in this step, the raw material can be stirred by rotating the stirring shaft 102 in the housing section 101b. This crushes the raw material to increase heating efficiency and allows the raw material to be heated uniformly through stirring. In addition, stirring suppresses the binding of the material being processed during the evaporation of water and thermal decomposition processes, making it easier to generate granular material.

[0034] In the cooling step S03, the granular material generated after the heating and stirring step S02 is cooled to 100°C or below. This cools the generated granular material. In this step, it is sufficient to cool the containment section 101b of the processing apparatus 100 to 100°C or below.

[0035] In the heating and stirring step S02, if the processing apparatus 100 as illustrated in Figure 1 is used, it is preferable that the processing in this step is carried out while leaving the granular material generated in the containment section 101b. In this case, for example, by operating the blower section 123 of the second heating unit 120, a cooling gas can be supplied from the air supply section 121 of the second heating unit 120 to the containment section 101b. The cooling gas can be an inert gas or air, adjusted to a temperature lower than that of the heating and stirring step S02. Specifically, the cooling gas can be obtained by stopping the heating section 124 or by setting the heating section 124 to a temperature lower than that of the heating and stirring step S02 (for example, 100°C or lower). The temperature reached in the containment section 101b in the cooling step S03 should be such that it is possible to check the generation status of the granular material and collect the granular material, and is preferably between 20°C and 80°C.

[0036] In this step, the raw materials may also be stirred while cooling by rotating the stirring shaft 102. This makes it possible to form finely crushed granular material with low viscosity, even if the raw materials contain thermoplastic resins that tend to increase in viscosity during the cooling process. Another advantage is that cooling efficiency can be improved by stirring the raw materials while cooling.

[0037] Each of these steps produces granular fiber material, which is a heat-treated raw material containing waste. In this embodiment, the granular fiber material undergoes gradual carbonization by heating with stirring in a temperature range of 180°C to 300°C. As a result, the granular fiber material of this embodiment has a characteristic structure in which it has larger pores and a lower surface porosity than carbonized materials such as activated carbon that are treated at higher temperatures. The structure of the granular fiber material will be described below.

[0038] [Granular material for fibers] As illustrated in Figure 3, the granular material 1 for fibers has a surface 2 containing irregularities and openings 3 formed on the surface 2. Figure 3 shows an image of the granular material for fibers according to an embodiment described later, taken with a scanning electron microscope at 1000x magnification.

[0039] The irregularities on surface 2 only need to be microscopic irregularities that are visible when magnified; for example, they should be detectable in an image taken by scanning electron microscope at a magnification of 100 times or more of the fiber granules 1. In the example in Figure 3, the irregularities on surface 2 are detected as shadows formed on surface 2.

[0040] The opening 3 is an opening formed in the depth direction from the surface 2, and is detected as a black void in an image of the fiber granules 1 magnified 500 times or more using a scanning electron microscope. In the example in Figure 3, the opening 3 is detected as a black area with a color similar to the black background. It is sufficient for one or more openings 3 to be formed in a single fragment of the fiber granules 1, and multiple openings may be formed.

[0041] The maximum dimension of the opening 3 is between 1 μm and 17 μm. The maximum dimension of the opening 3 is calculated as follows: First, the longest dimension of each opening 3 in one fragment of the fiber granules 1 is measured using an image taken with a scanning electron microscope at a magnification of 500x or more. Next, 10 images are taken, and the longest dimension of all the openings 3 in one fragment of the fiber granules 1 is taken as the maximum dimension of the opening 3 in that fragment.

[0042] In this embodiment, the porosity of surface 2 is 10% or less. The porosity in this specification is calculated as follows, with reference to Figure 4. First, a scanning electron microscope image (magnification 500 to 1000x) that clearly includes the surface 2 of one granular fiber material 1 is obtained, and the area of ​​surface 2 is calculated using image processing software or the like. In the example shown in Figure 4, the contour 2R shown by the thick line of surface 2 is defined, and the area enclosed by contour 2R is calculated. The definition of contour 2R may be performed automatically based on the distribution of brightness, etc., or at least part of it may be performed by an operator. Next, in the same image, the area of ​​the openings 3 formed on the surface 2 of the granular fiber material 1 is calculated. If the granular fiber material 1 has multiple openings 3, the sum of the areas of all openings 3 formed on the surface 2 of the granular fiber material 1 is calculated. In the example shown in Figure 4, for example, the contour 3R of the opening 3 is shown by the thick line. The area of ​​the opening 3 can be calculated as the area of ​​a region within the contour 2R of the surface 2 that has a brightness or lightness below a predetermined level, for example, equivalent to the black background. Then, the ratio of the total area of ​​the openings 3 to the area of ​​the surface 2, which is set to 100%, is calculated and defined as the opening ratio.

[0043] In this embodiment, the granular material for textiles has deodorizing properties. Deodorizing properties refer to the ability to reduce odors caused by odor components. As shown in the examples described later, the granular material for textiles in this embodiment can effectively reduce the odor of excrement.

[0044] One of the deodorizing mechanisms of granular materials for textiles is physical adsorption. Since granular materials for textiles have pores, it is presumed that odors can be suppressed by adsorbing odor component molecules into the interior of these pores.

[0045] Generally, carbides such as activated carbon are manufactured by carbonization treatment at temperatures between 300°C and 650°C, followed by activation treatment at even higher temperatures (700-1000°C). Carbonides treated at such high temperatures have pores called micropores, mesopores, and macropores, and it is known that they exhibit deodorizing properties by adsorbing odor components into these pores. Specifically, micropores are defined as pores with a diameter of 2 nm or less, mesopores as pores with a diameter of 2 to 50 nm, and macropores as pores with a diameter of 50 nm or more. On the other hand, the average pore diameter of activated carbon is said to be in the range of 1.2 nm to 3.0 nm, and the distribution of macropores with a diameter of 1.0 μm or more, such as the openings in this embodiment, is considered rare (Reference: Ishizuka et al., "Comparison of numerical analysis methods for activated carbon pore structure by nitrogen adsorption method", Carbon TANSO, 2007 (No.227) pp.103-p.106).

[0046] Furthermore, it is known that carbonized materials such as wood charcoal and bamboo charcoal tend to have an increasing pore volume around 0.5 nm as the heating temperature (400-900°C) increases (Reference: Akitomo et al., "Establishment of Measurement Methods for Microstructure of Wood Charcoal and Bamboo Charcoal and Possibility of Pore Control," Journal of the Japan Wood Research Society, Vol. 52, No. 4, pp. 228-234, (2006)). In other words, in carbonization treatment, it is thought that the volume of fine pores such as micropores increases as the treatment is performed at a high temperature.

[0047] In contrast to such carbides, the granular fiber material of this embodiment is subjected to a gradual carbonization treatment at a temperature of 180°C to 300°C. As a result, the pores do not become finer due to the progression of carbonization, and it is presumed that the granular fiber material has relatively large pores with a maximum size of 1 μm to 17 μm. Therefore, it is thought that the granular fiber material of this embodiment can adsorb odor components with large molecular weights (e.g., molecular weight of 65 or more) into its pores, which cannot be adsorbed by carbides with pores treated at temperatures above 300°C. In fact, the examples described later demonstrate that the granular fiber material of this embodiment exhibits high deodorizing properties against compounds having an indole skeleton with a molecular weight of 65 or more. Since compounds having an indole skeleton are known to be odor components of fecal odor, the granular fiber material of this embodiment can effectively deodorize excrement odors. Furthermore, as shown in the examples described later, the granular fiber material of this embodiment can also exhibit deodorizing properties against compounds with a molecular weight of less than 65, such as ammonia and acetic acid, which are known to be odor components of excrement odors, making it possible to deodorize excrement odors more effectively.

[0048] Compounds having an indole skeleton refer to compounds that have an indole skeleton as their basic structure, and various substituents may be introduced within the same molecule. Examples include indole, 1-methylindole, 2-methylindole, 5-methylindole, 7-methylindole, and skatole.

[0049] Furthermore, another deodorizing mechanism for the granular fiber material of this embodiment is chemical deodorization. Chemical deodorization is a deodorizing method that suppresses odors by chemically changing the structure of odor components with deodorizing components. From the viewpoint of effectively suppressing excretory odors by chemical deodorization, the granular fiber material of this embodiment preferably has a pH of 6 to 9. The pH of the granular fiber material is measured by the following method: 3.0 g of granular fiber material is added to 100 mL of water, boiled for 5 minutes while standing, and after cooling, the pH of the aqueous solution measured with a pH meter (e.g., "D-51 pH METER", manufactured by Horiba, Ltd.) is taken as the pH of the granular fiber material.

[0050] Generally, the raw materials for carbides contain organic substances such as carbon compounds and inorganic substances such as Na, Si, K, Ca, and Fe. As carbonization and ashing progress (for example, by processing at high temperatures for a long time), the organic substances volatilize, and the inorganic substances remain as ash. Since ash is basic, it is known that carbides become basic as carbonization progresses.

[0051] In contrast, the granular material for fibers of this embodiment is heated under low-temperature conditions (180°C to 300°C), so in addition to acidic organic substances, basic inorganic substances remain, and the pH tends to stay within the range of 6 to 9. As a result, it is thought that when the granular material for fibers of this embodiment comes into contact with acidic odor components, the basic components act to neutralize these odor components, and when it comes into contact with basic odor components, the acidic components act to neutralize these odor components. Therefore, the granular material for fibers of this embodiment can deodorize both acidic odor components such as acetic acid and compounds having an indole skeleton, and basic odor components such as ammonia, through a chemical deodorization mechanism, making it possible to suppress a wide range of excretory odors. It should be noted that for the granular material for fibers of this embodiment to exhibit deodorizing properties through chemical deodorization, it is preferable that the granular material and the excretory odor come into contact via moisture (for example, excretory substances such as urine or sweat).

[0052] [Examples of applications for granular fiber material] The granular material for fibers in this embodiment is added to the inside and / or outside of fibers and used in textile products. The fibers are not particularly limited, but examples include cellulose fibers (cotton, hemp, rayon, pulp, etc.), protein fibers (wool, silk, etc.), and synthetic fibers. The granular material for fibers in this embodiment is preferably used with pulp fibers and / or synthetic fibers, which are particularly versatile among these.

[0053] Examples of pulp fibers include chemical pulp (such as kraft pulp) produced by chemical methods from cellulose-containing raw materials such as wood, mechanical pulp produced by mechanically crushing the said raw materials, and recycled pulp fibers produced from recycled products. Of these, the granular material for fibers in this embodiment is more preferably used in recycled pulp fibers from the viewpoint of promoting resource circulation. Furthermore, it is preferable that the recycled pulp fibers are recycled pulp fibers produced by recovering pulp contained in used absorbent products. This makes it possible to produce a deodorizing fibrous product containing the granular material for fibers and recycled pulp fibers from used absorbent products, thereby promoting the recycling of used absorbent articles.

[0054] Synthetic fibers are not particularly limited, but examples include polyamide fibers, polyester fibers, polyacrylic fibers, polyvinyl alcohol fibers, polyvinyl chloride fibers, polyvinylidene chloride fibers, polyolefin fibers, polyurethane fibers, and the like.

[0055] In one embodiment of the present invention, a textile product containing the above-mentioned granular material for fibers can be provided. Examples of textile products include paper products, nonwoven fabrics, woven fabrics, and deodorizing sheets and deodorizing filters using these materials.

[0056] Examples of paper products include deodorizing paper, paper products made using deodorizing paper (containers, wallpaper, etc.), and paper molded products (pulp molded products). Of these, the paper product is preferably a highly versatile deodorizing paper. Alternatively, the paper product is preferably a container (sanitary box) for storing used absorbent articles. The method for manufacturing the paper product containing the above-mentioned granular material for fibers is not particularly limited. For example, the granular material for fibers may be added to a liquid used in a wet process such as a papermaking process to adhere the granular material to the fibers, or the granular material for fibers may be attached by coating with a paint mixed with the granular material for fibers. Alternatively, the granular material for fibers may be attached to the fibers by treatment such as pressurization and / or heating. Furthermore, the granular material for fibers may be added to the paper molded product during the molding process, such as pulp molding, to adhere the granular material to the fibers.

[0057] The nonwoven fabric is not particularly limited and examples include spunbond nonwoven fabrics, meltblown nonwoven fabrics, spunlace nonwoven fabrics, and chemical bond nonwoven fabrics. The method for producing the nonwoven fabric containing the above-mentioned fiber granules can be appropriately selected depending on the manufacturing process of the nonwoven fabric. For example, the fiber granules may be added to a liquid used in the wet process of manufacturing fiber webs to adhere the fiber granules to the fibers. Alternatively, the fibers to which the fiber granules have been added may be subjected to pressure and / or heat treatment. Alternatively, the fiber granules may be attached to the nonwoven fabric by coating it with a treatment solution mixed with the fiber granules and drying it. Furthermore, when using synthetic fibers, the fiber granules may be added to the inside of the fibers by mixing the fiber granules with the resin that is the raw material for the fibers and spinning the fibers.

[0058] As a method for manufacturing a woven fabric containing the above-mentioned granular material for fibers, for example, the fibers to which the granular material for fibers is attached may be subjected to treatment such as pressurization and / or heating. Alternatively, the granular material for fibers may be attached to the woven fabric by coating it with a treatment solution mixed with the granular material for fibers and drying it. Or, when using synthetic fibers, the granular material for fibers may be added to the inside of the fibers by mixing it with the resin that is the raw material for the fibers and spinning the fibers.

[0059] [Other embodiments] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the present invention.

[0060] The configuration of the processing apparatus 100 is not limited to the configuration shown in Figure 1 above. For example, as shown in Figure 5, the first heating unit 110 may be configured to heat the inside of the wall portion 101a with gas. Note that in the processing apparatus 100 shown in Figure 5, the same or corresponding configurations as those of the processing apparatus 100 shown in Figure 1 will not be described.

[0061] The first heating unit 110 shown in Figure 5 can heat the wall portion 101a by supplying heated gas into the wall portion 101a. In this example, the wall portion 101a has a space portion 101d that diffuses the supplied gas. The space portion 101d is configured to conduct heat to the inner surface of the wall portion 101a, and may be, for example, a space formed inside the wall portion 101a, or a tubular member or the like arranged inside the wall portion 101a. The arrangement of the space portion 101d is not particularly limited, but it is preferable that it be arranged over a wide area of ​​the wall portion 101a, and more preferably that it be arranged over the entire wall portion 101a.

[0062] In the example shown in Figure 5, the first heating unit 110 includes an in-wall air supply section 112, an in-wall exhaust section 113, a blower section 114, and a heating section 115. In this example, the first heating unit 110 operates the blower section 114 to exhaust gas from the space 101d via the in-wall exhaust section 113, heats the exhausted gas with the heating section 115, and supplies the heated gas from the in-wall air supply section 112 to the space 101d. Thus, the first heating unit 110 constitutes a hot air circulation type heating unit. The gas used in the first heating unit 110 is not particularly limited and may be air, nitrogen, or other inert gases.

[0063] The wall-mounted air supply unit 112 supplies gas to the space 101d inside the wall 101a. In this embodiment, the wall-mounted air supply unit 112 is configured as a gas passage connecting the space 101d and the heating unit 115. The wall-mounted air supply unit 112 is composed of one or more tubular members, for example, a tubular member connected to the space 101d.

[0064] The wall-mounted exhaust section 113 exhausts gas from the space 101d inside the wall section 101a. In this embodiment, the wall-mounted exhaust section 113 is configured as a gas passage connecting the air blower section 114 and the space 101d. The wall-mounted exhaust section 113 is composed of one or more tubular members, including, for example, a tubular member connected to the space 101d.

[0065] The air blower 114 blows gas into the wall-mounted air supply 112. The air blower 114 is composed of a blower such as a fan, blower, or compressor. In the example shown in Figure 5, the air blower 114 is located on the exhaust side of the heating unit 115, but it may also be located on the supply side.

[0066] The heating unit 115 heats the supplied gas. The heating unit 115 is composed of a heater, and from the viewpoint of facilitating temperature control, it is preferably composed of an electric heater. The heating method, installation position, and other configurations of the heater constituting the heating unit 115 can be determined in various ways depending on the configuration of the processing tank 101 and the properties of the raw materials.

[0067] Furthermore, the first heating unit 110 may have other components as needed. For example, the first heating unit 110 may have a valve member that can take in outside air and a valve member that can exhaust air. This allows the first heating unit 110 to perform cooling efficiently in the cooling step S03.

[0068] With the first heating unit 110 configured as described above, the heated gas can heat a wide area of ​​the inner surface of the wall portion 101a, and even if the volume of the storage portion 101b is increased, the storage portion 101b can be heated efficiently. Furthermore, by making the first heating unit 110 a circulating heating unit, waste heat can be recovered and energy efficiency can be increased. Therefore, with this configuration, energy consumption can be reduced and the volume of the storage portion 101b can be increased, further improving processing efficiency.

[0069] Furthermore, the configuration of the processing apparatus 100 is not limited to the above example and can be modified in various ways. For example, in the processing apparatus 100, it is not essential that the rotation axis C of the shaft portion 102a extends along the horizontal direction, and it may be inclined with respect to the horizontal plane. However, in order to effectively obtain the stirring action by gravity in the processing apparatus 100, it is necessary that at least the rotation axis C of the shaft portion 102a is inclined with respect to the vertical direction, and it is preferable that the angle of the rotation axis C of the shaft portion 102a with respect to the horizontal plane is small. Specifically, in the processing apparatus 100, it is preferable that the angle of the rotation axis C of the shaft portion 102a with respect to the horizontal plane is 30° or less.

[0070] In other embodiments, the cooling step S03, in which the inside of the housing 101b is cooled by the blower 123, is not mandatory, and the housing 101b may be cooled naturally, for example.

[0071] In yet another embodiment, granular material for fibers may be manufactured using apparatus other than the processing apparatus 100 described above.

[0072] In another embodiment, after the heating and stirring step S02, in which the material is heated at 180°C to 300°C, a heating step of 350°C to 375°C for 30 minutes or less may be performed. By performing such a heating step, even if the waste contains superabsorbent polymers with high thermal decomposition temperatures, the superabsorbent polymers can be thermally decomposed. This makes it possible to suppress the problem of the superabsorbent polymers in the granular material swelling due to moisture during the manufacture of textile products. In this heating step, although the temperature exceeds 300°C, the heating is for a short period of 30 minutes or less, so the pore size is not refined due to the progression of carbonization. [Examples]

[0073] The following describes embodiments of the present invention, but the present invention is not limited to the following embodiments.

[0074] [Production of granular materials] Using the apparatus described in Figure 1 in the above-described embodiment, granular material according to an embodiment of the present invention was produced. First, water was added to a diaper to simulate a used diaper, and the raw material was placed in the containment section of the apparatus. The containment section was heated and stirred until it reached 200°C, then maintained for 3 hours, and subsequently cooled. As a result, granular material with a particle size of 10 μm to 5 cm was obtained.

[0075] The generated granular material was imaged using a scanning electron microscope at 1000x magnification, and multiple images were obtained, including the image shown in Figure 3. Using these images, the maximum size of the pores and the porosity on the surface were calculated, and it was found that the maximum size of the pores was between 1 μm and 17 μm, and the porosity on the surface was 10% or less.

[0076] [pH measurement of granular materials] 3.0 g of the generated granular material was placed in a beaker containing 100 ml of water, boiled for 5 minutes while standing, and after cooling, the pH of the aqueous solution was measured using a pH meter ("D-51 pH METER," manufactured by Horiba, Ltd.). As a result, the pH of the granular material was found to be approximately 7.5.

[0077] [Evaluation of the deodorizing properties of granular material] The deodorizing properties of granular material were evaluated using odor components related to excrement odor. The evaluation of deodorizing properties was performed based on instrumental analysis test methods according to the SEK Mark Textile Product Certification Standards (ISO 17299-2 and ISO 17299-3). Ammonia, acetic acid, and indole (all gaseous) were prepared as odor components.

[0078] This section describes the method for evaluating the deodorizing properties of ammonia. Granular particles of 0 mg, 100 mg, 300 mg, and 500 mg were placed in different Erlenmeyer flasks, and 100 ppm (initial concentration) of ammonia was sealed into each flask. One Erlenmeyer flask containing the same amount of granular particles was prepared. After 2 hours, the ammonia concentration in each flask was measured using a detector tube. The average gas concentration (ppm) measured in the 0 mg (blank) sample was defined as Sb, and the average gas concentration (ppm) measured in each Erlenmeyer flask containing 100 mg, 300 mg, and 500 mg of granular particles was defined as Sm. The deodorizing concentration and odor reduction rate of ammonia were calculated as follows. The results are shown in Table 1 and Figure 6. Deodorization concentration (ppm) = Sb - Sm Odor reduction rate (%) = (Sb - Sm) / Sb × 100

[0079] The deodorizing properties of acetic acid were evaluated in the same manner as for ammonia, except that the initial concentration was set at 300 ppm. The results are shown in Table 1 and Figure 6.

[0080] This section describes the method for evaluating the deodorizing properties of indole. 50 mg and 100 mg of granular material were placed in separate Erlenmeyer flasks, and 33 ppm (initial concentration) of indole was sealed into each flask. Two Erlenmeyer flasks containing 100 mg of granular material were prepared. After 2 hours, the gas concentration (ppm) in the Erlenmeyer flasks was measured using a gas chromatograph ("GC-FID system," manufactured by Agilent Technologies). The deodorizing concentration and odor reduction rate of indole were calculated using the following formulas, with the initial concentration being Si and the measured gas concentration (ppm) being Sm. The results are shown in Table 1 and Figure 6. Deodorizing concentration (ppm) = Si - Sm Odor reduction rate (%)=(Si-Sm) / Si×100

[0081] [Table 1]

[0082] As shown in Table 1 and Figure 6, a clear reduction in odor was observed for all three odors: ammonia, acetic acid, and indole. Furthermore, for each odor component, the reduction rate of the odor component was positively correlated with the amount of granular material, indicating that the granular material has deodorizing properties. In particular, for indole, the odor reduction rate was approximately 90% at all amounts of granular material, indicating that the granular material used in the examples has very high deodorizing properties against indole.

[0083] [Preparation of deodorizing paper containing granular material] The granular material produced in the above example and crushed pulp fibers were prepared. A predetermined amount of the granular material was dispersed in water used in the papermaking process, and papermaking was carried out to produce deodorizing paper. The amount of added granular material was adjusted so that the granular material content in the produced paper was 10%, 20%, and 30% by mass.

[0084] Figures 7(A) to (D) show images of the surface of the fabricated paper, taken at 80x magnification using a scanning electron microscope ("JSM-6510", manufactured by JEOL Ltd.). (A) shows paper made only of pulp fibers, (B) shows paper containing 10% by mass of granular material, (C) shows paper containing 20% ​​by mass of granular material, and (D) shows paper containing 30% by mass of granular material. As shown in these figures, the granular material is intertwined with and adheres to the pulp fibers, demonstrating that it is possible to create deodorizing properties by incorporating granular material.

[0085] [Preparation of nonwoven fabric containing granular material] The granular material produced in the above example and the nonwoven fabric made from synthetic fibers (basis weight 40 g / m²) 2) and were prepared. The entire nonwoven fabric was placed in a resealable polyethylene bag. Granular material was then placed in this bag, and the bag was sealed by closing the zipper. The sealed bag was shaken up and down and side to side to ensure that the granular material adhered to the nonwoven fabric. After visually confirming that the granular material had adhered to the entire nonwoven fabric, the nonwoven fabric with the granular material attached was pressed in a press machine at 135°C for 30 seconds. This produced a nonwoven fabric containing granular material. The basis weight of the nonwoven fabric after the granular material was attached was 180 g / m². 2 The basis weight of the attached granular material is 140 g / m². 2 That was the case. [Explanation of Symbols]

[0086] 1. Granular material for fibers 2 surface 3 hole

Claims

1. A granular material for fibers which is a heat-treated product of raw materials including waste, It has a surface that includes irregularities and openings formed on the surface, The maximum size of the opening is 1 μm or more and 17 μm or less. The porosity of the surface is 10% or less. Having deodorizing properties, Granular material for fiber.

2. The pH is between 6 and 9. The granular material for fibers according to claim 1.

3. It has deodorizing properties against odor components containing compounds with a molecular weight of 65 or more. The granular material for fibers according to claim 1 or 2.

4. The odor component includes a compound having an indole skeleton. The granular material for fibers according to claim 3.

5. It has deodorizing properties against acetic acid. The granular material for fibers according to claim 1 or 2.

6. It has deodorizing properties against ammonia. The granular material for fibers according to claim 1 or 2.

7. The aforementioned waste includes combustible waste, The granular material for fibers according to claim 1 or 2.

8. The aforementioned waste includes thermoplastic resin, The granular material for fibers according to claim 7.

9. The aforementioned waste contains cellulose, The granular material for fibers according to claim 7.

10. The aforementioned waste contains a water-absorbent resin. The granular material for fibers according to claim 7.

11. The aforementioned waste includes absorbent articles, The granular material for fibers according to claim 7.

12. The aforementioned waste includes infectious waste, The granular material for fibers according to claim 7.

13. Used in pulp fibers and / or synthetic fibers, The granular material for fibers according to claim 1 or 2.

14. Used in recycled pulp fibers, The granular material for fibers according to claim 13.

15. A textile product comprising the granular material for fibers described in claim 1 or 2.

16. It is a paper product. The textile product according to claim 15.

17. Furthermore, it contains recycled pulp fibers, The textile product according to claim 16.

18. It is a nonwoven fabric. The textile product according to claim 15.

19. A method for producing granular fiber materials using waste, The process includes a step of stirring the raw materials, including waste, while heating them to a temperature between 180°C and 300°C. The aforementioned granular material for fibers is, It has a surface that includes irregularities and openings formed on the surface, The maximum size of the opening is 1 μm or more and 17 μm or less. The porosity of the surface is 10% or less. Having deodorizing properties, A method for producing granular materials for fiber.

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