Fiber processing method

Abstract

To provide a fiber processing method capable of quickly and excellently generating a second fibrillated material at a high yield without depending on conditions such as type, density, composition, twisting coefficient of a yarn of a roughly crushed piece.SOLUTION: A fiber processing method comprises: a fibrillating step to generate a first fibrillated material by applying a fibrillating processing to a roughly crushed piece of a fabric including a yarn in which a plurality of fibers are twisted; and a rag opening step to generate a second fibrillated material by a rag opening processing to the first fibrillated material. The method may have a roughly crushing step that is executed before the fibrillating step and generates the roughly crushed piece by roughly crushing the fabric.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for treating fibers. [Background technology]

[0002] Patent Document 1 discloses a technology for recycling textile products such as clothing. In Patent Document 1, a cutting process is performed in which the raw textile product is cut using a cutting machine, and a de-pilling process is performed in which the cut pieces produced in the cutting process are de-pilled using a de-pilling machine, thereby obtaining finely de-pilled fibers. These finely de-pilled fibers are then reused. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2017-531103 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the method described in Patent Document 1 may not be able to obtain finely disaggregated fibers depending on conditions such as the type and material of the raw material. For example, if the raw material contains a yarn in which the fibers are relatively tightly twisted, the method described in Patent Document 1 will not be able to disaggregate the fibers. Fibers that are not disaggregated cannot be reused as they are, resulting in a low yield. [Means for solving the problem]

[0005] The fiber processing method of the present invention includes a defibration step of performing a defibration process on coarsely crushed pieces of fabric including a yarn in which a plurality of fibers are twisted to generate a first defibrated material; and a de-fibering step of performing de-fibering treatment on the first defibrated material to generate a second defibrated material. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a longitudinal sectional view showing an embodiment of a fiber processing apparatus for carrying out a fiber processing method of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 3 is an enlarged schematic view of the coarsely crushed pieces shown in FIG. [Figure 4] FIG. 4 is an enlarged schematic view of the first defibrated material shown in FIG. [Figure 5] FIG. 5 is an enlarged schematic view of the second defibrated material shown in FIG. [Figure 6] FIG. 6 is an enlarged photograph of the first unresolved yarn. [Figure 7] FIG. 7 is an enlarged photograph of the first unresolved yarn. [Figure 8] FIG. 8 is a table (Table 1) showing the measured values ​​in each example of the present invention. [Figure 9] FIG. 9 is a table (Table 2) showing the measured values ​​in each example of the present invention. [Figure 10] FIG. 10 is a table (Table 3) showing the measured values ​​in each example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0007] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The fiber processing method of the present invention will be described in detail below with reference to preferred embodiments shown in the accompanying drawings.

[0008] <Embodiment> Fig. 1 is a longitudinal cross-sectional view showing an embodiment of a fiber processing device that executes the fiber processing method of the present invention. Fig. 2 is a cross-sectional view taken along line AA in Fig. 1. Fig. 3 is an enlarged schematic view of the coarsely crushed pieces shown in Fig. 1. Fig. 4 is an enlarged schematic view of the first defibrated material shown in Fig. 1. Fig. 5 is an enlarged schematic view of the second defibrated material shown in Fig. 1. Figs. 6 and 7 are enlarged photographs of the first undefibrated yarn.

[0009] In the following, the upper side of Figure 1 may be referred to as "top" or "upper," and the lower side as "bottom." The left side of Figure 1 may be referred to as "left" or "left side," and the right side as "right" or "right side."

[0010] The fiber processing device 100 shown in Figure 1 carries out the fiber processing method of the present invention, and processes cloth fabric, which is raw material M0, to generate second defibrated material M3 via coarsely crushed pieces M1 and first defibrated material M2. The fiber processing device 100 comprises a coarse crushing device 1, a defibrating device 2, and a depilling device 6.

[0011] Examples of fabrics that are raw materials M0 include various cloth products such as cloth (woven, nonwoven, or knitted), clothing, handkerchiefs, towels, bedding, curtains, and carpets, whether they are unused or used.

[0012] The second defibrated material M3 produced by the fiber processing device 100 is stored in a predetermined location (not shown), or is recycled into cloth or various cloth products through a spinning device (not shown) or the like.

[0013] As shown in Figure 1, the crushing device 1 is a device that performs a crushing step in which raw material M0 is crushed to produce crushed pieces M1. Raw material M0 is a fabric containing yarn T in which fibers F are twisted. The fibers F contained in raw material M0 are not particularly limited, but examples include natural fibers such as cotton, wool, silk, and linen; regenerated fibers such as rayon, polynosic, cupra, and lyocell; and synthetic fibers such as nylon, polyester, acrylic, vinylon, and polyurethane; and one or a combination of two or more of these fibers can be used.

[0014] The crushing device 1 has a pair of crushing blades 11 arranged parallel to and spaced apart from each other, and a chute 12 installed below the crushing blades 11.

[0015] The pair of crushing blades 11 rotate in opposite directions to each other, crushing the raw material M0 between them, i.e., cutting it to generate crushed pieces M1. The shape and size of the crushed pieces M1 are preferably suitable for the defibration process in the defibration device 2. Examples of the shape of the crushed pieces M1 include small pieces with a square planar shape, rectangular pieces, and particularly small strip-shaped pieces. The size of the crushed pieces M1 is not particularly limited, but is preferably small pieces with an average side length of 100 mm or less, and more preferably small pieces with an average side length of 3 mm or more and 70 mm or less. The shape of the small pieces may be other than square or rectangular. The thickness of the crushed pieces M1 is not particularly limited, but is preferably 0.07 mm or more and 5.00 mm or less.

[0016] The chute 12 is disposed below the pair of crushing blades 11 and is, for example, conical or funnel-shaped. This allows the chute 12 to receive the coarsely crushed pieces M1 that have been crushed by the crushing blades 11 and dropped. The lower part of the chute 12 is connected to the inlet 31 of the defibrator 2, and the coarsely crushed pieces M1 collected by the chute 12 are supplied to the defibrator 2 from the inlet 31.

[0017] As shown in Fig. 3, the coarse fragments M1 are in a state where yarns T are knitted or woven into them. The yarns T contained in the coarse fragments M1 are hereinafter referred to as pre-disintegrated yarns T1.

[0018] The twist coefficient kA of the fibers F in the open-end yarn T1 is not particularly limited, but is preferably 2 or more and 6 or less, and more preferably 3 or more and 5 or less.

[0019] The twist factor k in this specification is calculated by (T / inch) / √count (Ne), where T refers to the number of twists per unit length (1 inch), and Ne refers to the cotton count.

[0020] The density ρA of the fibers F in the defibrated yarn T1 is not particularly limited, but is preferably 0.001 g / cm 3 More than 1.500g / cm 3 Preferably, it is 0.010 g / cm or less.3 More than 1.000g / cm 3 More preferably, it is:

[0021] The average yarn length LA of the pre-opening yarns T1 is not particularly limited, but is preferably 10 mm or more and 100 mm or less, and more preferably 15 mm or more and 60 mm or less.

[0022] It is to be noted that the crushing device 1 may be omitted. When the crushing device 1 is omitted, separately prepared crushed pieces or a raw material in a similar form is supplied directly to the defibrating device 2.

[0023] The defibrator 2 shown in Figure 1 is a device that performs a defibration step in which coarsely crushed pieces M1 are defibrated in the air to produce first defibrated material M2. As shown in Figure 1, the defibrator 2 has a casing 3, a liner 4 arranged along the inner circumferential surface of the casing 3, a rotor 5 as a rotating body that is rotatably installed inside the casing 3, and a motor M that drives the rotor 5 to rotate. The coarsely crushed pieces M1 are defibrated when they pass between the outer periphery of the rotating rotor 5 and the liner 4, and become the first defibrated material M2.

[0024] The casing 3 has an inlet 31 for feeding the coarse fragments M1 into the casing 3, and an outlet 32 ​​for discharging the produced first defibrated material M2 to the outside of the casing 3. The casing 3 is a cylindrical member having an internal space S0 for accommodating the liner 4 and the rotor 5.

[0025] The input port 31 is provided on the side near the left end of the casing 3. The input port 31 is provided in a cylindrical shape that protrudes radially outward from the casing 3.

[0026] The discharge port 32 is provided on the side near the right end of the casing 3. The discharge port 32 is provided in a cylindrical shape that protrudes radially outward from the casing 3.

[0027] The inlet 31 and the outlet 32 ​​are located at the upper part of the casing 3 in FIG. 1. As shown in FIG. 2, the protruding direction of the inlet 31 and the outlet 32 ​​is tangent to the inner periphery of the casing 3. However, the positions at which the inlet 31 and the outlet 32 ​​are formed are not limited to the above, and they may be shifted by a predetermined angle or on opposite sides, and the protruding direction is also not particularly limited.

[0028] 1, the casing 3 has partition plates 33 and 34 provided in the internal space S0. Partition plate 33 is provided on an extension of the inlet 31, with its thickness direction aligned with a rotation shaft 51 (described later). Partition plate 34 is provided on an extension of the outlet 32, with its thickness direction aligned with the rotation shaft 51. Partition plates 33 and 34 are disposed substantially parallel to each other. The ends of partition plates 33 and 34 on the rotation shaft 51 side are spaced apart from the rotation shaft 51.

[0029] By providing the partition plate 33, the coarse fragments M1 fed from the feed port 31 can be smoothly introduced up to the vicinity of the rotation shaft 51. This contributes to the smooth transfer of the coarse fragments M1 in the internal space S0. Furthermore, by providing the partition plate 34, the generated first defibrated material M2 can be smoothly guided to the discharge port 32. This allows the first defibrated material M2 to be discharged more smoothly.

[0030] As shown in Figures 1 and 2, the liner 4 is a cylindrical member arranged around the entire inner circumferential surface of the cylindrical portion of the casing 3 between the inlet 31 and the outlet 32. The central axis of the liner 4 is coaxial with the rotation shaft 51. As shown in Figures 1 and 2, the outer circumferential surface of the liner 4 is fixed to the inner circumferential surface of the casing 3. As shown in Figure 1, the axial length of the liner 4 is long enough to encompass the blades 521, which will be described later. The liner 4 is made of a hard material such as metal.

[0031] In addition, teeth 41 serving as fixed blades are formed on the inner periphery of the liner 4. The teeth 41 defibrate the coarsely crushed pieces M1 between them and the rotor 5. The teeth 41 are provided along the circumferential direction of the liner 4, and have a plurality of protrusions 411 that protrude toward the center. The protrusions 411 also extend along the axial direction of the casing 3. Each protrusion 411 has the same protrusion height and has an apex 412 that is a cutting edge. The center of a circle C connecting each apex 412 is concentric with the rotation axis 51.

[0032] When the coarsely crushed pieces M1 pass between the outer periphery of the rotating rotor 5 and the teeth 41, they collide with the protruding parts 411 of the teeth 41 and are defibrated, producing a first defibrated material M2.

[0033] As shown in FIG. 1, the rotor 5 has a rotating shaft 51, a rotor portion 52, a side plate 54 located on the left side of the rotor portion 52, and a side plate 55 located on the right side of the rotor portion 52.

[0034] The rotating shaft 51 is elongated and installed so as to extend in the left-right direction and pass through the casing 3. The rotating shaft 51 is rotatably supported by the casing 3 via a bearing (not shown), and its right end is connected to the output shaft of the motor M. When current is applied to the motor M, the motor M is driven and the rotating shaft 51 rotates in a predetermined direction. A reducer (not shown) may be installed between the output shaft of the motor M and the rotating shaft 51.

[0035] Disk-shaped side plates 54 and 55 are fixed to and spaced apart from each other midway along the length of rotating shaft 51. Side plates 54 and 55 have through holes 56 and 57 in the center, respectively, through which rotating shaft 51 is inserted and fixed. Side plates 54 and 55 are fixed to rotating shaft 51 by fitting rotating shaft 51 into through holes 56 and 57 formed in side plates 54 and 55.

[0036] 1 and 2, the rotor unit 52 has a plurality of blades 521 as rotary blades arranged radially around the rotation axis 51. In this embodiment, the number of blades 521 is eight. The blades 521 are arranged at equal angular intervals around the rotation axis 51. Note that the size, number of blades 521, arrangement pattern, etc. are not particularly limited in the present invention.

[0037] Each blade 521 is plate-shaped, particularly flat, and is arranged with each main surface oriented along the radial direction of the casing 3 and the rotor 5. Each blade 521 is fixed to a side plate 54 and a side plate 55, respectively. An end 522 on the outer periphery of each blade 521, i.e., the side farther from the rotation shaft 51, is spaced a predetermined distance from the top 412 of the protrusion 411 and rotates without contacting the liner 4. The side plates 54 and 55 are arranged at a predetermined interval along the axial direction of the rotation shaft 51 and substantially parallel to each other. The end 522 on the outer periphery of each blade 521 is the cutting edge.

[0038] Each blade 521 is not limited to being a flat plate, but may be curved or bent into a desired shape.

[0039] Each blade 521 is fixed to the rotating shaft 51 via a side plate 54 and a side plate 55. As a result, when the rotating shaft 51 rotates, each blade 521 rotates around the rotating shaft 51 together with the side plate 54 and the side plate 55. The coarsely crushed pieces M1 are defibrated when they pass between each rotating blade 521 and the teeth 41 of the liner 4.

[0040] In this embodiment, each blade 521 has the same shape and size. However, this is not limiting, and at least one of the blades 521 may have a different shape or size from the others.

[0041] The teeth 41 and the blade 521 are preferably made of hard metal materials or ceramics, such as stainless steel, Inconel, Hasselloy, titanium or titanium-based alloys, carbon tool steel, alloy tool steel (carbon tool steel containing nickel, chromium, molybdenum, tungsten, etc.), high-speed steel (containing tungsten, vanadium, cobalt, etc.), powdered high-speed steel (high-speed steel material that has been powdered to remove impurities and then vacuum-melted to increase its purity), cemented carbide (material obtained by sintering a material primarily composed of tungsten carbide, titanium carbide, or tantalum carbide with cobalt), cermet, sintered aluminum oxide, cubic boron nitride, sintered diamond, etc. The materials of the teeth 41 and the blade 521 may be the same or different.

[0042] 2, the discharge port 32 is located on the opposite side of the input port 31 in the axial direction of the rotation shaft 51, and although it does not actually exist, the discharge port 32 is depicted by a dashed line to make it easier to understand its placement, etc. However, the present invention is not limited to this configuration, and the input port 31 and the discharge port 32 may be located in any position.

[0043] By using this type of defibrator 2, the crushed pieces M1 are subjected to a defibration process to generate a first defibrated material M2. At this time, the defibration process is terminated before the crushed pieces M1 are completely broken down into fibers by the defibration process. The first defibrated material M2 generated in this way contains defibrated cotton, in which the threads that make up the crushed pieces M1 are broken down into fibers, and undefibrated yarns, in which the threads are not defibrated and remain in a thread state for the most part. In the defibration process of the present invention, it is desirable that the amount of undefibrated yarns is greater than the amount of defibrated cotton. For example, as shown in FIG. 4, the first defibrated material M2 contains undefibrated yarns T made of fiber F, and its content is approximately 50% by mass or more. The yarns T contained in the first defibrated material M2 will be referred to below as first undefibrated yarns T2.

[0044] The twist coefficient kB of the fibers F in the first unresolved yarn T2 is not particularly limited, but is preferably 2.0 or more and 5.0 or less, and more preferably 2.5 or more and 4.0 or less.

[0045] The density ρB of the fibers F in the first unfibrillated yarn T2 is not particularly limited, but is preferably 0.001 g / cm 3 More than 0.500g / cm 3 Preferably, it is 0.005 g / cm or less. 3 More than 0.250g / cm 3 More preferably, it is:

[0046] The average fiber length LB of the first unfibrillated yarns T2 is not particularly limited, but is preferably 10 mm or more and 100 mm or less, and more preferably 15 mm or more and 80 mm or less.

[0047] As shown in FIG. 1, the hair returning device 6 is a device that performs a hair returning process by performing a hair returning process on the first defibrated material M2 to produce a second defibrated material M3. The hair returning device 6 has five hair returning rollers 61, 62, 63, 64, and 65, and a housing 66 that houses them. The hair returning rollers 61, 62, 63, 64, and 65 are each installed so that they can rotate around their central axes. The hair returning rollers 61, 62, 63, 64, and 65 are each installed so that their rotation axes are parallel. In this embodiment, the hair returning rollers 61, 63, and 64 each rotate clockwise in FIG. 1, and the hair returning rollers 62 and 65 each rotate counterclockwise in FIG. 1.

[0048] The housing 66 has an inlet 661 on the left side and an outlet 662 on the right side. The inlet 661 is connected to the outlet 32 ​​of the defibrator 2 via a transfer pipe (not shown). The first defibrated material M2 that is discharged from the outlet 32 ​​and passes through the transfer pipe is introduced into the housing 66 from the inlet 661. The first defibrated material M2 introduced from the inlet 661 in this way is subjected to a de-pilling process by the de-pilling rollers 61, 62, 63, 64, and 65, the fibers F are untangled, and the second defibrated material M3 is generated. The second defibrated material M3 is discharged from the outlet 662.

[0049] The outer diameter of the hair-reducing roller 61 is smaller than the outer diameter of the hair-reducing roller 62. The outer diameter of the hair-reducing roller 63 is larger than the outer diameters of the hair-reducing rollers 61, 62, 64, and 65. The outer diameter of the hair-reducing roller 64 is the same as the outer diameter of the hair-reducing roller 61. The outer diameter of the hair-reducing roller 65 is the same as the outer diameter of the hair-reducing roller 62.

[0050] The hair removing roller 61 has a blade 611 on its outer periphery. The hair removing roller 62 has a blade 621 on its outer periphery. The hair removing roller 63 has a blade 631 on its outer periphery. The hair removing roller 64 has a blade 641 on its outer periphery. The hair removing roller 65 has a blade 651 on its outer periphery.

[0051] The shapes (width, height, pitch, etc.), forming locations, and forming numbers of the blades 611, 621, 631, 641, and 651 may be the same or different.

[0052] The first defibrated material M2 discharged from the discharge outlet 32 ​​of the defibrator 2 passes through a transfer pipe and is introduced into the housing 66 from the inlet 661, and passes sequentially between each of the pile-removing rollers 61, 62, 63, 64 and 65, during which time it is subjected to pile-removal processing by blade 611, blade 621, blade 631, blade 641 and blade 651.

[0053] The pile returning roller 61 and the pile returning roller 62 are installed inside the housing 66 near the discharge outlet 32 ​​of the defibrator 2. The pile returning roller 61 and the pile returning roller 62 are arranged side by side in the vertical direction, in this order from bottom to top. As the pile returning roller 61 and the pile returning roller 62 rotate in opposite directions, the first defibrated material M2 introduced into the housing 66 is first subjected to pile returning processing by the blades 611 and 621 while being transported to the right side in FIG. 1.

[0054] The pile-returning roller 63 is installed in the center of the housing 66, and rotates clockwise in Fig. 1. That is, the pile-returning roller 63 is installed to the right of the pile-returning roller 61 and the pile-returning roller 62. The pile-returning roller 63 rotates in the same direction as the pile-returning roller 61, and thereby the first defibrated material M2 is transported along the outer periphery of the pile-returning roller 63 while being subjected to pile-returning processing by the blade 631.

[0055] The pile returning roller 64 is installed to the right of the pile returning rollers 61 and 62, and above the pile returning roller 63. As the pile returning rollers 63 and 64 rotate in the same direction, the first defibrated material M2 is transported to the right in FIG. 1 while being subjected to a powerful pile returning process by the blades 631 and 641.

[0056] The pile returning roller 65 is installed to the right of the pile returning roller 64 and above the pile returning roller 63. By the pile returning roller 63 and the pile returning roller 65 rotating in opposite directions, the first defibrated material M2 is transported to the right in FIG. 1 while being subjected to a powerful pile returning process by the blades 631 and 651.

[0057] The first defibrated material M2 introduced into the housing 66 from the inlet 661 is subjected to a depilating process by the blades 611, 621, 631, 641 and 651 of the depilating rollers 61, 62, 63, 64 and 65 which rotate in a predetermined direction, and the second defibrated material M3 is produced. The produced second defibrated material M3 is discharged from the outlet 662.

[0058] The constituent materials of the hair removing rollers 61, 62, 63, 64 and 65 or the blades 611, 621, 631, 641 and 651 are not particularly limited, but may include those listed above as constituent materials of the teeth 41 and blade 521.

[0059] By performing the de-pilling process on the first defibrated material M2, the first undefibrated yarns T2 are broken down into fibers and defibrated cotton is generated. As shown in Fig. 5, the second defibrated material M3 mainly contains defibrated cotton in which the fibers F are defibrated into individual fibers. Furthermore, the second defibrated material M3 may contain second undefibrated yarns T3 that were not defibrated by the de-pilling process, but the content thereof is, for example, 50 mass % or less of the second defibrated material M3.

[0060] The density ρC of the defibrated cotton fibers F contained in the second defibrated material M3 is not particularly limited, but is preferably 0.001 g / cm 3 More than 0.500g / cm 3 Preferably, it is 0.005 g / cm or less. 3 More than 0.250g / cm 3 More preferably, it is:

[0061] The average fiber length LC of the fibers F of the defibrated cotton contained in the second defibrated material M3 is not particularly limited, but is preferably 10 mm or more, and more preferably 15 mm or more.

[0062] Conventionally, it is common to immediately perform a de-pilling process on the cut pieces corresponding to the coarsely crushed pieces M1 to obtain regenerated fibers corresponding to the second defibrated material M3. However, with this conventional method, depending on the conditions of the fiber type, composition, density, composition, twist coefficient, fiber length, fiber diameter, etc. of the yarn contained in the cut pieces, the fibers may not be sufficiently disentangled, and some may be in a state that makes them difficult to use as regenerated fibers, resulting in poor yield. Increasing the number of de-pilling processes can be considered to improve yield, but in this case, the average fiber length of the obtained regenerated fibers may become shorter or the fibers may become damaged, again resulting in poor quality of the regenerated fibers.

[0063] In contrast, in the present invention, a defibrating process is performed prior to the de-fibering process. That is, in the defibrating process, the yarns T (pre-defibrating yarns T1) of the crushed pieces M1 are unraveled and the twist of the fibers F is slightly weakened, thereby generating first undefibrated yarns T2. Then, the de-fibering process is performed on these first undefibrated yarns T2. With this method, recyclable fibers can be obtained quickly and with high quality at a high yield, regardless of the various conditions (hereinafter simply referred to as "various conditions") such as the type, density, composition, twist coefficient, fiber length, and fiber diameter of the yarns T (pre-defibrated yarns T1) of the crushed pieces M1. Furthermore, in the de-fibering process, the closer the object to be processed is to a yarn state, the higher the defibrating efficiency. Therefore, the first undefibrated yarns T2 contained in the first defibrated material M2 are decomposed into fibers by a relatively short de-fibering process. As a result, the time required for the de-fibering process is shortened. Furthermore, the shorter the time for the recovery process, the less the fibers deteriorate, allowing for the extraction of high-quality fibers for regeneration.

[0064] In this way, the fiber processing method of the present invention comprises a defibrating process in which coarsely crushed pieces M1 of raw material M0, which is a fabric containing yarn T (pre-defibration yarn T1) in which multiple fibers are twisted, are defibrated to produce a first defibrated material M2, and a de-pilling process in which the first defibrated material M2 is de-pilled to produce a second defibrated material M3. This makes it possible to produce the second defibrated material M3 quickly and well with a high yield, regardless of various conditions such as the type, density, composition, twist coefficient, fiber length, and fiber diameter of the yarn T (pre-defibration yarn T1) of the coarsely crushed pieces M1.

[0065] In the fiber processing method of the present invention, the defibration process is carried out using a defibration device 2, and the depilation process is carried out using a depilation device 6. This allows each process to be carried out more quickly and effectively, and the quality of the obtained second defibrated material M3 is also uniform. In addition, each process can be automated. Therefore, the second defibrated material M3 can be produced efficiently with a high yield.

[0066] The first defibrated material M2 contains first undefibrated yarns T2, and when the density of the fibers F in the pre-defibrated yarns T1 contained in the coarse fragments M1 is ρA and the density of the fibers F in the first undefibrated yarns T2 contained in the first defibrated material M2 is ρB, ρB / ρA is preferably 0.2 or more and 0.9 or less, and more preferably 0.3 or more and 0.8 or less. By performing processing to satisfy these conditions, the second defibrated material M3 can be produced quickly and well with a high yield.

[0067] If ρB / ρA is too large, depending on the conditions, the defibration process may be insufficient, which may diminish the effects of the present invention. On the other hand, if ρB / ρA is too small, the defibration process will be carried out sufficiently, but the time required for the defibration process will tend to be long and the average fiber length of the fibers F of the first undefibrated yarn T2 will tend to be relatively short.

[0068] The first defibrated material M2 contains first undefibrated yarns T2, and when the twist coefficient of the fibers F in the pre-defibrated yarns T1 contained in the coarse fragments M1 is kA, and the twist coefficient of the fibers F in the first undefibrated yarns T2 contained in the first defibrated material M2 is kB, kB / kA is preferably 0.2 or more and less than 1.0, and more preferably 0.3 or more and 0.95 or less. By performing processing to satisfy these conditions, the second defibrated material M3 can be produced quickly and well with a high yield.

[0069] If kB / kA is too large, depending on the conditions, the defibration process may be insufficient, and the effects of the present invention may be diminished. On the other hand, if kB / kA is too small, the defibration process may be carried out sufficiently, but the time required for the defibration process may tend to be longer and the average fiber length of the fibers F of the first undefibrated yarn T2 may tend to be relatively short.

[0070] The first defibrated material M2 contains first undefibrated yarns T2, and when the average fiber length of the pre-defibrated yarns T1 contained in the coarse fragments M1 is LA and the average fiber length of the first undefibrated yarns T2 contained in the first defibrated material M2 is LB, LB / LA is preferably 0.1 or more and 0.95 or less, and more preferably 0.7 or more and 0.9 or less. By performing processing to satisfy these conditions, the second defibrated material M3 can be produced quickly and well with a high yield.

[0071] If the LB / LA ratio is too large, depending on the conditions, the defibration process may be insufficient, and the effects of the present invention may be diminished.On the other hand, if the LB / LA ratio is too small, the fiber may not be suitable for recycling, depending on the conditions and the product to be recycled.

[0072] The fiber processing method of the present invention has a crushing step that is carried out before the defibrating step, in which the raw material M0, which is the fabric, is crushed to produce crushed pieces M1. This makes it possible to easily and appropriately produce crushed pieces M1 that meet the conditions suitable for the defibrating step. This allows the recovered fiber processing to be carried out more efficiently. Furthermore, the fabric crushing step, defibrating step, and recovered fiber step can be carried out consecutively, improving the production efficiency of the second defibrated material M3.

[0073] While the fiber processing method of the present invention has been described above with reference to the illustrated embodiment, the present invention is not limited to this, and each step constituting the fiber processing method can be replaced with any step that can exert a similar function. In addition, any other feature may be added to the fiber processing method. [Example]

[0074] The results obtained by carrying out the present invention as described above will be explained as examples. Examples 1 and 2, shown in Tables 1 to 3 in Figures 8 to 10, show the properties of each product when plain weave cotton fabrics of different characteristics were subjected to the defibrating and recovering processes based on the above-mentioned embodiment. Note that Example 1 used fabric as raw material with a basis weight of 270, a yarn count of 22 / 2, 12.0 twists of the yarns constituting the fabric, and a twist coefficient of 2.55, while Example 2 used fabric as raw material with a basis weight of 164, a yarn count of 32, 25.1 twists of the yarns constituting the fabric, and a twist coefficient of 4.44.

[0075] (Measurement method) The measured values ​​in Examples 1 and 2 were obtained by the following measurement methods. Note that the measurement methods described below are known methods such as those disclosed in Japanese Patent No. 6556974.

[0076] (1) Metsuke The basis weight was measured in accordance with JIS L 1096 (2010).

[0077] (2) Yarn count Measurement was performed in accordance with the cotton count measurement method for measuring the correct tex and count of general spun yarns in JIS L 1095:2010 9.4.1.

[0078] (3) Number of twists and twist factor The number of twists was measured in accordance with JIS L 1095:2010 9.15.1A method, and the twist coefficient was calculated using the following formula. Twist factor = number of twists (T / inch) / √ count (Ne)

[0079] (4) Density ρB of the first unresolved yarn T2 The procedure for calculating the density ρB of the fibers contained in the first unresolved yarns T2 will be described below.

[0080] (I) Calculation of the yarn diameter based on side observation of the first unresolved yarn T2 In order to obtain a thread-like image of the first unresolved yarn T2 contained in the first defibrated material M2, a photograph was taken using a microscope. Using a KEYENCE VHX-5000 digital microscope, the first unresolved yarn T2 was placed horizontally and the side of the yarn was photographed at a magnification of 40x to 100x. The photographed image is shown in Figure 6. Then, as shown in Figure 6, at an arbitrary location of the first unresolved yarn T2, a tangent line La extending in the longitudinal direction of the yarn was drawn to the outermost fiber among the fibers constituting the yarn, and a perpendicular line Lp perpendicular to the tangent line La was drawn. The intersection of the perpendicular line Lp and the tangent line La was called intersection point A. Furthermore, the outermost fiber on the opposite side of the tangent line La across the central axis of the yarn was identified, and the intersection point of this fiber and the perpendicular line Lp was called intersection point B. The distance between intersection point A and intersection point B was measured from the image, and this distance was considered to be the diameter of the first unresolved yarn T2. Five images were taken of different locations for one sample. The yarn diameters at five locations in each image were calculated and used as the representative value for that image. The average value of the five images was then calculated and used as the representative value for that sample. Note that fibers that were more than five times the diameter of the fiber from adjacent fibers in the direction of the center of the yarn cross section were excluded from the outermost fibers when measuring.

[0081] (II) Calculation of density ρB of first defibrated yarn T2 The density ρB of the first unresolved yarn T2 is calculated by dividing the weight per unit length of the yarn by the volume per unit length of the yarn. The following calculation method is used in detail, and the density obtained by such a calculation is called the apparent density of the yarn.

[0082] First, the weight of the yarn per unit length (1 m) is calculated from the correct count (JIS L 1095 9.4.1 Correct Tex and Count). Then, using the diameter of the yarn measured in (I) above, the cross-sectional area of ​​the yarn is calculated assuming that the cross section of the yarn is circular. The volume of the yarn per unit length (1 m) is the value obtained by multiplying the cross-sectional area by 1, and this value is used to determine the volume of the yarn. Then, the weight per unit length is divided by the volume per unit length to calculate the apparent density of the yarn. This apparent density is the density ρB of the first unresolved yarn T2. ​​Note that the smaller the apparent density, the greater the bulk of the yarn per unit length.

[0083] (5) Ratio of first undefibrated yarn T2 contained in first defibrated material M2 After the defibration process, the first defibrated material M2 contains thread-like undefibrated yarns in which fibers remain twisted together in bundles, and defibrated cotton that has been broken down into fibers. 50.0 mg ± 0.5 mg of the first defibrated material M2 was sampled, and the first undefibrated yarn T2 was sampled from it and its weight was measured. Then, the proportion of the weight of the first defibrated material M2 that was accounted for by the first undefibrated yarn T2 was calculated. The measurement was performed twice, and the average value was calculated and used as the representative value for that sample.

[0084] (6) Number of twists and twist coefficient of the first undefibrated yarn T2 contained in the first defibrated material M2 (I) Measurement of the number of twists from the side of the yarn (a) As shown in FIG. 7, the first unfibrillated yarn T2 was placed horizontally, and an image of the side of the yarn (50 to 100 times magnification) was obtained using a KEYENCE VE-9800 electron microscope.

[0085] (b) At the top of the acquired side image of the yarn, the outermost end points AL and AR were obtained for the intersections of the line formed by the outermost fiber on the side of the yarn and the edge of the image, and La was drawn by connecting these two points with a straight line. Note that fibers that were located at a distance from adjacent fibers more than five times the diameter of the fiber toward the center of the yarn cross section were excluded from the measurement.

[0086] (c) On the lower side of the side image of the first unresolved yarn T2 obtained, the outermost end points BL and BR were obtained for the intersections of the straight lines formed by the fibers present at the outermost side of the yarn and the edge of the image, and Lb was drawn by connecting these two points with a straight line. Note that fibers that had a location where the distance from adjacent fibers toward the center of the yarn cross section was five times or more the diameter of that fiber were excluded from the measurement.

[0087] (d) CL and CR were obtained as the midpoints in the cross-sectional direction of the yarn at the left and right ends of the side image of the first unresolved yarn T2, respectively, and the yarn axis Lc was obtained by connecting these two points with a straight line.

[0088] (e) The intersection of a fiber on an arbitrary yarn surface and the yarn axis Lc was designated as intersection point D, and a tangent line Ld to the fiber on the yarn surface was drawn so as to pass through intersection point D. The intersection point of La and Ld was designated as AD, and the intersection point of Lb and Ld was designated as BD.

[0089] (f) A perpendicular line is drawn from AD to Lc, and the intersection point E of the perpendicular line with Lc is obtained. A perpendicular line is drawn from BD to Lc, and the intersection point F of the perpendicular line with Lc is obtained.

[0090] (g) The length between intersections E and F was measured to determine the length required for the fiber to make half a turn, i.e., the yarn length per 0.5 twists. The number of twists per inch was calculated from the yarn length. Measurements were performed five times per image, and the average value was used as the representative value for that image. Measurements were performed on three images, and the average value was used as the representative value.

[0091] (II) Calculation of twist coefficient The twist coefficient was calculated using the following formula. Twist factor = twists (T / inch) / √ count (Ne)

[0092] (7) Average yarn length LB of the first unresolved yarn T2 The first unresolved yarns T2 separated in (5) above were measured in accordance with JIS L 1015 C method. Each first unresolved yarn T2 was randomly picked up, stretched straight without stretching, and its length was measured on a measuring scale. The average length of 200 yarns was used as the representative value.

[0093] (8) Ratio of defibrated cotton (fiber) contained in the second defibrated material M3 to the second defibrated yarn T3 A thread-like material in which fibers were twisted into bundles was extracted from the second defibrated material M3 as second undefibrated yarn T3. Furthermore, the defibrated, cotton-like fibers were extracted as defibrated cotton. 50.0 mg ± 0.5 mg of the second defibrated material M3 was sampled and separated into defibrated cotton and undefibrated yarn, and the weight of each was measured, and the weight percentage of each to the weight of the second defibrated material M3 was calculated. The measurement was carried out twice, and the average value was calculated and used as the representative value for that sample.

[0094] (9) Length of fiber F of defibrated cotton contained in second defibrated material M3 The fiber F contained in the defibrated cotton classified in (8) above was measured in accordance with JIS L 1015 C method. Fibers were randomly picked one by one, stretched straight without stretching, and the fiber length was measured on a measuring scale. The average length of 200 fibers was used as the representative value.

[0095] The measured values ​​obtained by the above-mentioned measurement method are shown in Tables 1 to 3 in Figures 8 to 10. As can be seen from Table 1, in both Example 1 and Example 2, the length of the first undefibrated yarn T2 contained in the first defibrated material M2 does not decrease significantly from the raw material yarn length even after the defibrating process, and further, the length of the fiber F obtained after the recovering process is equivalent to the length of the first undefibrated yarn T2, so by performing the process of the present invention on the raw material fabric, fiber F suitable for recycling could be produced. Note that the reason that the length of fiber F is slightly longer than the length of the first undefibrated yarn T2 is presumed to be because when the first undefibrated yarn T2 is defibrated by the recovering process, the twist of the fiber is removed, causing the apparent length to increase slightly.

[0096] Furthermore, the numerical values ​​of the number of twists, twist coefficient, and fiber density of the first undefibrated yarn T2 do not change significantly from the numerical values ​​of the pre-defibrated yarn T1. This means that even though the coarse fragments M1 are broken down by the defibration process, most of the fibers maintain their fibrous state. Then, by performing a depilling process on the first defibrated material M2 that maintains its fibrous state, fibers F suitable for recycling can be obtained.

[0097] Table 2 shows the calculated ratios of the measured values ​​of fiber density, twist coefficient, and fiber length before and after the defibration treatment in Examples 1 and 2. All values ​​were within the appropriate range, indicating that a first undefibrated yarn T2 with the desired properties was obtained by the defibration treatment.

[0098] Additionally, Table 3 shows the weight percentages of the ingredients contained in the first defibrated material M2 and the second defibrated material M3. In both Examples 1 and 2, the majority of the first defibrated material M2 is made up of first undefibrated yarns T2, and it can be seen that many of the fibers maintain their thread state even after the defibration process.

[0099] Then, by depilling, most of the yarns are converted into fibers, and the proportion of yarns in the second defibrated material M3 is significantly reduced. As a result, it is possible to obtain a sufficient amount of fiber (defibrated cotton) for recycling.

[0100] In conventional wool-recovery technology, it was difficult to turn fabrics made of highly twisted yarns into fibers, and such fabrics were difficult to recycle, so they had to be discarded. In contrast, as is clear from the above examples, the present invention makes it possible to extract fibers suitable for recycling from fabrics made of twisted yarns, making it possible to recycle fabrics that would previously have had to be discarded. [Explanation of symbols]

[0101] 1... coarse crushing device, 2... defibrator, 3... casing, 4... liner, 5... rotor, 6... hair recovery device, 11... coarse crushing blade, 12... chute, 31... inlet, 32... outlet, 33... partition plate, 34... partition plate, 41... teeth, 51... rotating shaft, 52... rotor part, 54... side plate, 55... side plate, 56... through hole, 57... through hole, 61... hair recovery roller, 62... hair recovery roller, 63... hair recovery roller, 64... hair recovery roller, 65... hair recovery roller roller, 66...housing, 100...fiber processing device, 411...projection, 412...top, 521...blade, 522...end, 611...edge, 621...blade, 631...blade, 641...blade, 651...blade, 661...inlet, 662...outlet, C...circle, F...fiber, G...separation distance, M...motor, M0...raw material, M1...coarsely crushed pieces, M2...first defibrated material, M3...second defibrated material, S0...internal space, T...yarn, T1...pre-defibrated yarn, T2...first undefibrated yarn

Claims

1. a defibration step of performing a defibration process on coarsely crushed pieces of fabric including yarns in which a plurality of fibers are twisted to generate a first defibrated material; a depilating step of performing depilating treatment on the first defibrated material to generate a second defibrated material.

2. the first defibrated material includes undefibrated yarns, 2. The fiber processing method according to claim 1, wherein ρB / ρA is 0.2 or more and 0.9 or less, where ρA is the fiber density of the pre-defibrated yarn contained in the coarse fragments and ρB is the fiber density of the undefibrated yarn contained in the first defibrated material.

3. the first defibrated material includes undefibrated yarns, 2. The fiber processing method according to claim 1, wherein kB / kA is equal to or greater than 0.2 and less than 1.0, where kA is the twist coefficient of the fibers in the pre-defibrated yarn contained in the coarse fragments, and kB is the twist coefficient of the fibers in the undefibrated yarn contained in the first defibrated material.

4. the first defibrated material includes undefibrated yarns, The fiber processing method according to claim 1, wherein LB / LA is 0.1 or more and 0.95 or less, where LA is the average fiber length of the pre-defibrated yarns contained in the coarse fragments and LB is the average fiber length of the undefibrated yarns contained in the first defibrated material.

5. The fiber processing method according to claim 1 , further comprising a crushing step, which is carried out before the defibrating step, of crushing the fabric to generate the crushed pieces.

6. The defibration process is carried out using a defibration device, 5. The fiber processing method according to claim 1, wherein the depilling is carried out using a depilling device.

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