Decoloring method and decoloring device

Abstract

[Problem] To be able to properly decolorize a material without burdening the user. [Solution] A decolorization method for decolorizing the pigment of a dye from a material containing fibers dyed or colored with a dye, wherein the pigment is retained in the interstices of the molecular chains of the fibers. The decolorization method includes a decolorization step of washing the material with a first decolorizing solution at a decolorization temperature above a fiber-opening temperature, the fiber-opening temperature being a temperature at which the molecular chains relax to the point that the pigment is released from the interstices of the molecular chains of the fibers contained in the material.

Description

Technical Field

[0001] This invention relates to a decolorization method and a decolorization apparatus. Background Technology

[0002] Currently, there are known techniques for printing on fabrics using transfer printing. Transfer printing is a printing method in which an image is drawn on a transfer sheet using transfer ink, and the image drawn on the transfer sheet is then transferred to fabric. Furthermore, for the recycling of fabrics, there are known techniques for decolorizing the fabric to remove the image from the fabric.

[0003] For example, Patent Document 1 describes a technique for discharge dyeing dyed fabric by printing a discharge agent using an inkjet printer. Patent Document 1 also describes an inkjet printing apparatus that sprays out discharge ink for this type of discharge dyeing.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2007-224128 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] Typically, decolorization of a substance requires not only the addition of a solvent to the substance, but also hot pressing of the substance and the absorbent to absorb the solvent, supplying the absorbent to the substance, and transporting the substance.

[0009] Therefore, it is difficult to decolorize objects with three-dimensional shapes, such as stuffed toys. Furthermore, large absorbents proportional to the area to be decolorized are required. Since a large amount of absorbent becomes waste as the object to be decolorized increases in size, this is uneconomical and has a high environmental impact.

[0010] Furthermore, ideally, the series of processes required for decolorizing the object should be performed automatically with minimal burden on the user (especially in terms of labor or health).

[0011] The inkjet printing apparatus described in Patent Document 1 is not an apparatus capable of automatically performing the series of processes required for decolorization, which may create a burden for the user.

[0012] Therefore, it is required to be able to properly decolorize objects without burdening users.

[0013] Technical means to solve the problem

[0014] According to a first aspect of the invention, a decolorization method involves decolorizing the pigment of a dye from a material containing fibers dyed or colored with a dye, wherein...

[0015] The pigment is retained in the gaps between the molecular chains of the fiber.

[0016] The decolorization method includes a decolorization step in which the object to be decolorized is cleaned with a first decolorizing solution. The decolorization temperature of the first decolorizing solution is above the fiber-opening temperature, which is the temperature at which the molecular chains relax to the point that the pigment is released from the gaps between the molecular chains of the fibers contained in the object to be decolorized.

[0017] It is possible that the dye is a disperse dye.

[0018] The fiber is a fiber that can be dyed or colored by the disperse dye.

[0019] Alternatively, in the decolorization process, the fibers may be brought into contact with the first decolorizing liquid at the decolorization temperature in a treatment tank.

[0020] Alternatively, in the decolorization process, the object to be decolorized is moved into the first decolorizing liquid in the treatment tank containing the first decolorizing liquid heated to the decolorization temperature.

[0021] Alternatively, in the decolorization process, the first decolorizing liquid is heated to the decolorization temperature in the treatment tank containing the object to be decolorized and the first decolorizing liquid at a temperature lower than the decolorization temperature.

[0022] The decolorization process may include a stimulation application process, wherein the stimulation application process applies mechanical stimulation to the decolorized object after or during contact between the first decolorizing liquid and the fiber.

[0023] The stimulation application process may include any one of the following steps: stirring the first decolorizing liquid containing the decolorized object in the treatment tank, a vibration process, and an ultrasonic treatment process.

[0024] The decolorization process can be carried out simultaneously by supplying new or recycled first decolorizing liquid to the treatment tank and discharging excess first decolorizing liquid from the treatment tank.

[0025] The decolorization process may include the step of spraying the first decolorizing liquid onto the object to be decolorized in liquid or gas form at the decolorization temperature.

[0026] It may also include a rinsing step after the decolorization step, in which a second decolorizing solution for decolorizing the pigment is brought into contact with the object to be decolorized.

[0027] It is possible that the second decolorizing solution is a liquid of the same type as the first decolorizing solution.

[0028] It may also include a dehydration step of removing the first decolorizing liquid from the decolorized object, and a drying step of drying the decolorized object.

[0029] The fiber may include at least one of polyester fiber and nylon fiber.

[0030] The decolorization temperature may be lower than the boiling point of the first decolorization solution.

[0031] According to a second aspect of the invention, a decolorizing apparatus removes pigment from a material containing fibers dyed or colored with a dye, the decolorizing apparatus comprising:

[0032] The decolorization section washes the object to be decolorized with a first decolorizing solution for decolorizing the dye. The decolorization temperature of the first decolorizing solution is above the fiber-opening temperature, which is the temperature at which the molecular chains relax to the point that the pigment is released from the gaps between the molecular chains of the fibers contained in the object to be decolorized.

[0033] An exhaust device is used to exhaust the fumes from the first decolorizing liquid generated in the decolorizing section;

[0034] A smoke recovery device that restores the smoke to a liquid state and recycles it; and

[0035] The conveying unit moves the decolorized object into the decolorization unit and moves the decolorized object out of the decolorization unit after decolorization.

[0036] Alternatively, the decolorizing device may further include a sealed frame housing the decolorizing section and the conveying section.

[0037] The exhaust device is installed in the sealed frame to expel the smoke from the inside of the sealed frame to the outside.

[0038] Alternatively, the decolorizing device may further include a hood, which is disposed above and covers the opening through which the smoke is discharged from the decolorizing section.

[0039] The exhaust device is installed on the cover.

[0040] The decolorization section may include a first processing tank for loading the first decolorizing liquid, a first storage tank for storing the first decolorizing liquid and supplying the first decolorizing liquid to the first processing tank, and a heating device for heating the first decolorizing liquid in the first processing tank or the first storage tank to the decolorization temperature.

[0041] The decolorization section may include a stimulation device that applies mechanical stimulation to the object to be decolorized.

[0042] The stimulation device may include at least one of the following: a stirring device for stirring the decolorized object and the first decolorizing liquid in the first treatment tank; a oscillating device for oscillating the first decolorizing liquid and the decolorized object together in the first treatment tank; an ultrasonic treatment device for ultrasonically treating the first decolorizing liquid and the decolorized object together in the first treatment tank; and a stirring blade configured to contact the decolorized object in the first treatment tank.

[0043] The decolorizing unit may, while supplying the first decolorizing liquid from the first storage tank to the first processing tank and discharging excess first decolorizing liquid from the first processing tank, clean the object to be decolorized using the first decolorizing liquid.

[0044] The decolorizing section may include a spraying device that sprays the first decolorizing liquid at the decolorizing temperature onto the object to be decolorized in the form of a liquid or a gas.

[0045] Alternatively, the decolorizing section may further clean the decolorized object that has been decolorized by the first decolorizing solution with a second decolorizing solution, wherein the temperature of the second decolorizing solution is lower than the fiber opening temperature and decolorizes the dye.

[0046] Alternatively, the decolorizing device may further include a rinsing section, which cleans the material to be decolorized in the decolorizing section with a second decolorizing solution. The temperature of the second decolorizing solution is lower than the fiber opening temperature and it decolorizes the dye.

[0047] The conveying section transports the decolorized object from the decolorization section to the rinsing section.

[0048] Alternatively, the decolorizing apparatus may further include an impurity removal device, which removes the dye from the used first decolorizing liquid discharged from the decolorizing section.

[0049] The decolorization apparatus may further include a dehydration device for removing liquid from the object to be decolorized, and...

[0050] A drying apparatus for drying the decolorized object.

[0051] The decolorization device can be constructed to explosion-proof specifications.

[0052] The fiber may include at least one of polyester fiber and nylon fiber.

[0053] The effects of the invention

[0054] According to the present invention, it is possible to properly decolorize objects without burdening the user. Attached Figure Description

[0055] [ Figure 1 [1] is a flowchart of the decolorization method according to the first embodiment of the present invention.

[0056] [ Figure 2 [ ] is a structural diagram of the decolorization apparatus according to the second embodiment of the present invention.

[0057] [ Figure 3 [This is a schematic diagram (viewed from the side) of the decolorization apparatus according to the second embodiment of the present invention.]

[0058] [ Figure 4 [This is a schematic diagram (viewed from the side) of the decolorizing section of the decolorizing apparatus according to the second embodiment of the present invention.]

[0059] [ Figure 5 [This is a schematic diagram (viewed from the side) of the rinsing section of the decolorizing apparatus according to the second embodiment of the present invention.]

[0060] [ Figure 6 [This is a schematic diagram (viewed from the side) of the decolorizing section of a decolorizing apparatus according to a modified example of the present invention.]

[0061] [ Figure 7 [ ] is a schematic diagram (viewed from the side) of a decolorization apparatus of a modified example of the present invention. Detailed Implementation

[0062] (First Implementation)

[0063] The decolorization method of the first embodiment of the present invention will be described.

[0064] This decolorization method involves using a decolorizing solution to decolorize disperse dyes that have been dyed or colored onto the object to be decolorized.

[0065] In this decolorization method, such as Figure 1 As shown, the main processes are decolorization (S1), rinsing (S2), dehydration (S3), and drying (S4).

[0066] (Object to be decolorized)

[0067] The object to be decolorized is any article containing polyester or nylon fibers. The object to be decolorized includes polyester or nylon fibers that have been dyed or colored with disperse dyes.

[0068] For example, the material to be decolorized may include knitted fabrics or cloths made of polyester yarn, nylon yarn, polyester blended yarn, or nylon blended yarn. Examples of fibers blended with polyester or nylon include cotton, polyurethane, rayon, linen, etc., as well as blends of polyester and nylon.

[0069] The blending ratio of polyester or nylon to other blended yarns (polyester or nylon: other blended yarns) can be set to any ratio in the range of 50:50 to 90:10.

[0070] The shape of the object to be decolorized is arbitrary; examples include flags, clothing, and fabrics. Additionally, it can include three-dimensional items such as stuffed toys.

[0071] (Disperse dyes)

[0072] Disperse dyes are any dyes that can dye or color the fibers of the polyester or nylon fiber being decolorized by ingesting the pigment contained in the disperse dye into the gaps between the molecular chains of the fiber being decolorized.

[0073] Methods for dyeing polyester or nylon fibers in a decolorized object with disperse dyes include sublimation transfer printing, direct sublimation printing, exhaustion dyeing, and hot melt dyeing.

[0074] (Decolorizing solution)

[0075] The decolorizing solution used in the decolorization process S1 and rinsing process S2 described later can be selected arbitrarily as long as the following conditions are met.

[0076] (i) has a boiling point that exceeds the temperature at which the decolorization process S1 and the rinsing process S2 are performed.

[0077] (ii) It can dissolve disperse dyes.

[0078] (iii) It will not have a significant adverse effect on the decolorized object.

[0079] Here, the boiling point of (i) is preferably a boiling point that exceeds the temperature (decolorization temperature) during decolorization in the decolorization process S1.

[0080] Furthermore, as an example of the “adverse effects” described in (iii), examples include changes in the hue of the fibers themselves constituting the decolorized object, deterioration of the fiber feel, and shrinkage of the fibers.

[0081] Organic solvents can be listed as the main components of a decolorizing solution. Examples of organic solvents include dimethyl succinate (boiling point: 200°C), dimethyl glutarate (boiling point: 214°C), dimethyl adipate (boiling point: 245°C), diethylene glycol monoethyl ether acetate (boiling point: 218°C), 3-methoxy-N,N-dimethylpropionamide (boiling point: 215°C), benzyl benzoate (boiling point: 325°C), diethylene glycol (boiling point: 245°C), trichloroethane (boiling point: 74°C), dimethyl sulfoxide (boiling point: 189°C), acetone (boiling point: 56°C), methyl ethyl ketone (boiling point: 80°C), and propylene glycol monomethyl ether acetate (boiling point: 146°C). When using the organic solvents listed here, they can be appropriately diluted with water or other organic solvents before use.

[0082] (Decolorization process S1)

[0083] In the decolorization process S1, the object to be decolorized is cleaned in a first treatment tank using a decolorizing solution. Here, the first treatment tank contains a decolorizing solution heated to a specified decolorization temperature.

[0084] In polyester or nylon fibers dyed with disperse dyes, the pigment of the disperse dye remains in the interstices of the fiber's molecular chains. At room temperature, the pigment of the disperse dye present in the interstices of the molecular chains has high wash resistance; the pigment of the disperse dye does not easily detach from the interstices of the molecular chains. That is, polyester or nylon fibers dyed with disperse dyes are not easily bleached.

[0085] However, if polyester or nylon fibers are heated at high temperatures, the gaps between the molecular chains widen, making it easier for the disperse dye pigments to escape from these gaps (the fibers). In other words, polyester or nylon fibers dyed with disperse dyes are easily decolorized.

[0086] Therefore, in the decolorization process S1, a decolorization temperature above the fiber-opening temperature is used as the decolorization temperature. Here, the fiber-opening temperature refers to the temperature at which the gaps between the molecular chains of the polyester or nylon fibers contained in the object to be decolorized widen (relax) to the point that the pigment of the disperse dye is released from the gaps between the molecular chains.

[0087] For example, the decolorization temperature only needs to be above the glass transition point of the polyester or nylon fibers contained in the object being decolorized.

[0088] Furthermore, the decolorization temperature is determined based on the dyeing temperature of the polyester or nylon fibers contained in the material to be decolorized during the exhaustion dyeing process; for example, it can be above the dyeing temperature. In particular, when the material to be decolorized contains polyester fibers, the decolorization temperature can be 110°C or higher, 115°C or higher, 120°C or higher, 125°C or higher, or 130°C or higher.

[0089] In addition, when the object to be decolorized contains nylon fibers, the decolorization temperature can be above 70°C, above 80°C, above 90°C, or above 100°C.

[0090] Furthermore, when using any decolorization temperature, the upper limit of the decolorization temperature is the boiling point of the decolorizing solution. The upper limit of the decolorization temperature varies depending on the fibers constituting the material to be decolorized.

[0091] Here, "boiling point" is not limited to boiling point under normal pressure, but also includes boiling point under pressure.

[0092] In the decolorization process S1, in order to clean and decolorize the object to be decolorized by the decolorization liquid, a heating process is mainly performed to heat the object to be decolorized by the decolorization liquid, and a stirring process to stir the object to be decolorized and the decolorization liquid.

[0093] In the heating process, the object to be decolorized is heated by the decolorizing solution in a first treatment tank containing the decolorizing solution at the decolorizing temperature. For example, the object to be decolorized is brought into contact with the decolorizing solution at the decolorizing temperature in the first treatment tank. Specifically, the fibers contained in the object to be decolorized are brought into contact with the decolorizing solution at the decolorizing temperature. As a result, the temperature of the object to be decolorized approaches the decolorizing temperature, and the gaps between the molecular chains of the polyester or nylon fibers contained in the object to be decolorized widen. As a result, it is expected that the pigment of the disperse dye, which is held in the gaps between the molecular chains, will be released from the gaps between the molecular chains, thereby making the object to be decolorized easier.

[0094] The heating process can be carried out by simultaneously or sequentially adding the object to be decolorized and the decolorizing solution heated to the decolorization temperature into the first treatment tank. For example, the decolorizing solution heated to the decolorization temperature can be prepared in advance in the first treatment tank, and the object to be decolorized can be transferred into the second treatment tank containing the decolorizing solution.

[0095] Alternatively, the heating process can be carried out by simultaneously or sequentially adding the object to be decolorized and the decolorizing liquid into the first treatment tank, and then heating the decolorizing liquid in the first treatment tank containing the object to be decolorized and the decolorizing liquid to the decolorization temperature.

[0096] In either the case of using a decolorizing solution heated to the decolorization temperature or heating the decolorizing solution in the first treatment tank, the order in which the object to be decolorized and the decolorizing solution are added to the first treatment tank can be either one first.

[0097] In the stirring process, the object to be decolorized and the decolorizing solution are stirred in the first treatment tank.

[0098] The stirring process can be performed after the heating process or in parallel with the heating process. When the stirring process is performed in parallel with the heating process, it can be performed as follows: (i) the object to be decolorized is immersed (contacted) in the decolorizing solution in the first treatment tank for a specified time to allow the decolorizing solution to penetrate into the fibers, and then the stirring process is performed; (ii) the decolorization process is performed without ensuring the immersion time, and the object to be decolorized is stirred in the decolorizing solution while the decolorizing solution penetrates into the fibers.

[0099] Therefore, it is hoped that this will promote the release of disperse dye pigments from the gaps between fiber molecular chains that have been relaxed by heating.

[0100] (Rinsing process S2)

[0101] In the rinsing step S2, the material to be decolorized is cleaned in a second treatment tank containing a decolorizing solution at a temperature lower than the fiber opening temperature. The rinsing step S2 mainly includes a cooling step to cool the material to be decolorized using the decolorizing solution, and a stirring step to agitate both the material to be decolorized and the decolorizing solution.

[0102] In the cooling process, the decolorized object after the decolorization process S1 is cooled in the second processing tank.

[0103] The second processing tank contains a bleaching solution at a temperature below the fiber opening temperature, such as room temperature or ambient temperature (e.g., about 20°C or 25°C). Within the second processing tank, the material to be bleached is cooled by contact with the bleaching solution. In other words, the material to be bleached is cooled via the bleaching solution.

[0104] For example, the material to be decolorized is brought into contact with a decolorizing solution at a temperature below the fiber-opening temperature in a first treatment tank. Specifically, the fibers contained in the material to be decolorized are brought into contact with a decolorizing solution at a temperature below the fiber-opening temperature. If the temperature of the material to be decolorized is lowered below the fiber-opening temperature by contact with the decolorizing solution, the molecular chain structure of the polyester or nylon fibers contained in the material to be decolorized is restored. As a result, the gaps between the widened molecular chains return to their original state and narrow, thus it is expected that the pigments of the disperse dyes remaining on the surface of the material to be decolorized will not be reabsorbed into the gaps between the molecular chains of the fibers.

[0105] The cooling process can be performed by simultaneously or sequentially adding the object to be decolorized and a decolorizing solution at a temperature lower than the fiber-opening temperature into the second treatment tank. For example, a decolorizing solution at a temperature lower than the fiber-opening temperature can be prepared in advance in the second treatment tank, and the object to be decolorized can be transferred into the second treatment tank containing the decolorizing solution. Alternatively, the cooling process can also be performed by adding a decolorizing solution at a temperature lower than the fiber-opening temperature into the second treatment tank after the object to be decolorized has been transferred into the second treatment tank.

[0106] In the stirring process, the object to be decolorized and the decolorizing solution are stirred in the second treatment tank.

[0107] The stirring process can be performed after or in parallel with the cooling process. This allows the pigments of the disperse dye remaining on the surface of the object to be decolorized to dissolve in the decolorizing solution, thus removing them from the surface of the object more reliably.

[0108] (Dehydration process S3)

[0109] In the dewatering step S3, the decolorized material after the rinsing step S2 is removed from the second processing tank, and the decolorizing liquid is removed from the decolorized material. Dewatering can be carried out, for example, by a centrifugal or pressing dewatering device (dehydration device).

[0110] (Drying process S4)

[0111] In drying step S4, the decolorized material after liquid removal is dried. Examples of drying methods include natural drying, press drying, and air drying. In natural drying, the decolorized material is dried by placing it at room temperature or ambient temperature (25°C). In press drying, heat and pressure are applied coaxially using a pressing device to dry the decolorized material. In air drying, warm air is blown onto the decolorized material to dry it.

[0112] (Effects of the first implementation method)

[0113] Traditionally, dye is removed from fabrics by coating them with a bleaching liquid, pressing an absorbent over them, and applying heat. However, this method is difficult to use on three-dimensional objects such as stuffed toys. Furthermore, the need for a large absorbent proportional to the area to be bleached means that a large amount of absorbent becomes waste when the object is large, making it uneconomical and environmentally burdensome. These uneconomical and environmentally unfriendly practices effectively limit the size of objects to be bleached.

[0114] On the other hand, according to the decolorization method of this embodiment, disperse dyes can be decolorized from the object to be decolorized by washing it with a decolorizing solution heated to a predetermined decolorization temperature. Therefore, in this decolorization method, the shape of the object to be decolorized is not limited to a two-dimensional surface, and three-dimensional products can also be decolorized.

[0115] Furthermore, since this decolorization method does not require an absorber, increasing the size of the object to be decolorized will not cause economic or environmental problems, and therefore the size of the object to be decolorized is not as limited as in the past. Therefore, according to this decolorization method, the object to be decolorized can be appropriately decolorized regardless of its shape or size.

[0116] (Variation Example 1-1)

[0117] The decolorization process S1 can be achieved by any method as long as the object to be decolorized is cleaned with a decolorizing solution that can dissolve disperse dyes at a decolorization temperature above the glass transition point of the polyester or nylon fibers contained in the object to be decolorized at a temperature above the glass transition point of the polyester or nylon fibers contained in the object to be decolorized.

[0118] (Variation Example 1-1-1)

[0119] In the first embodiment, an example is provided where a stirring step is performed in the decolorization step S1 to agitate the object to be decolorized and the decolorizing solution, thereby applying mechanical stimulation to the object to be decolorized. As long as the pigment of the disperse dye can be decolorized from the object to be decolorized, mechanical stimulation can also be applied to the object to be decolorized by methods other than stirring. For example, a stimulation application step can be performed instead of a stirring step.

[0120] Methods for applying mechanical stimulation to the object to be decolorized during the stimulation application process include, for example, oscillating the decolorizing liquid and the object to be decolorized together in a first treatment tank, subjecting the decolorizing liquid and the object to be decolorized together to ultrasonic treatment in a first treatment tank, or stimulating the object to be decolorized by contacting a rotating blade with it in a first treatment tank.

[0121] (Variation 1-1-2)

[0122] In the first embodiment and the modified examples described therein, a stirring step or a stimulation application step of applying mechanical stimulation is performed in the decolorization step S1 to stir the decolorized object and the decolorization liquid.

[0123] It can replace the stirring process or the stimulation application process, or, in addition to the stirring process or the stimulation application process, perform a relative movement process in which the decolorizing liquid moves relative to the surface of the object to be decolorized.

[0124] In the relative movement process, the decolorizing solution is moved relative to the surface of the object to be decolorized, thereby supplying a relatively fresh, unused decolorizing solution to the surface of the object, and the effect is induced by the movement of the decolorizing solution. Therefore, it is expected to promote the decolorization of disperse dyes.

[0125] For example, in the decolorization step S1, when replacing the stirring step or the stimulation application step, or when a relative movement step is performed in addition to the stirring step or the stimulation application step, new decolorizing liquid or recycled decolorizing liquid can be supplied to the first treatment tank, and excess decolorizing liquid can be discharged from the first treatment tank.

[0126] As a result, due to the flow of the decolorizing liquid in the first treatment tank, the decolorizing liquid moves relative to the object to be decolorized.

[0127] Alternatively, in this case, the used decolorizing liquid discharged from the first treatment tank can be re-supplied to the first treatment tank. That is, the decolorizing liquid can be circulated. Furthermore, in this case, the decolorizing liquid can be circulated while removing impurities from it. Examples of impurities mentioned here include foreign matter, disperse dyes dissolved in the decolorizing liquid, specifically disperse dye pigments, etc. The removal of impurities can be achieved, for example, by filtering the decolorizing liquid using activated carbon or by distilling the decolorizing liquid.

[0128] (Variation 1-1-3)

[0129] In the first embodiment and the modified examples described therein, in the decolorization process S1, a used decolorization solution that has had impurities removed can be used instead of a new decolorization solution.

[0130] For example, the waste decolorizing liquid generated in the decolorization process S1 can be recovered each time a decolorization process is performed, and after removing impurities, it can be used in the next decolorization process S1 or rinsing process S2.

[0131] Alternatively, for example, the decolorizing solution that has been circulated through the first treatment tank and in which impurities have been removed during the circulation process can be used for the decolorizing process S1. That is, the decolorizing process S1 can be performed simultaneously with the removal of impurities from the decolorizing solution.

[0132] For example, in the decolorization process S1, excess decolorizing liquid can be discharged from the first processing tank, impurities can be removed from the discharged decolorizing liquid, and the decolorizing liquid can be re-supplied to the first processing tank.

[0133] (Variation 1-1-4)

[0134] In the first embodiment, an example is shown where the object to be decolorized is cleaned in a first treatment tank containing a decolorizing solution at a predetermined decolorizing temperature during the decolorization process S1. However, if the object to be decolorized can be cleaned with a decolorizing solution at a predetermined decolorizing temperature, the treatment tank may not be necessary.

[0135] For example, the decolorization process S1 can also be carried out by spraying a decolorizing liquid at the decolorization temperature onto the object to be decolorized in a liquid or gaseous state.

[0136] For example, the decolorizing liquid can be sprayed onto the object to be decolorized in the form of steam, droplets, or mist at the decolorization temperature using a steam iron or atomizer, especially a high-pressure steam iron or atomizer.

[0137] If vapors of a decolorizing liquid heated to the decolorization temperature are sprayed onto the object to be decolorized, the object will be heated by the vapors of the heated decolorizing liquid. Therefore, the same effect as the heating step can be expected. Furthermore, since the object to be decolorized is subjected to mechanical stimulation by spraying the decolorizing liquid, the same effect as the stirring step and the stimulation application step can also be expected.

[0138] In particular, to increase the intensity of the mechanical stimulation applied to the object to be decolorized and the flow of the decolorizing liquid on the surface of the object, it is preferable to spray the vapor, droplets, or mist of the decolorizing liquid forcefully under high pressure. In other words, by spraying the decolorizing liquid onto the object to be decolorized in liquid or gas form at the decolorization temperature, the heating process of heating the object to be decolorized and the stimulation application process of applying mechanical stimulation to the object to be decolorized can be performed simultaneously.

[0139] (Variation 1-1-5)

[0140] In the first embodiment and the modified examples described above, a heating step, a stirring step, a stimulation application step, or a relative movement step are performed in the decolorization step S1. However, the stirring step, stimulation application step, or relative movement step may be omitted. In this case, the decolorization temperature may be higher in the heating step, and / or the time for which the object to be decolorized is in contact with the decolorizing liquid may be longer than in the case where the stirring step, stimulation application step, or relative movement step is performed.

[0141] (Variations 1-2)

[0142] The rinsing process S2 can be achieved by any method as long as the decolorizing solution at a temperature lower than the fiber opening temperature comes into contact with the object to be decolorized (the fiber of the object to be decolorized).

[0143] (Variation 1-2-1)

[0144] Except for the cooling process replacing the heating process, the rinsing process S2 can be performed in the same way as the decolorizing process S1. Therefore, except for the cooling process replacing the heating process, the aforementioned variation of the decolorizing process S1 can also be applied to the rinsing process S2.

[0145] Furthermore, if the stirring step, stimulation application step, or relative movement step in the rinsing step S2 is omitted, the time that the object to be decolorized is in contact with the decolorizing liquid in the cooling step can be longer than if the stirring step, stimulation application step, or relative movement step is performed.

[0146] Furthermore, the methods for applying mechanical stimulation to the object to be decolorized in the decolorization process S1 and the rinsing process S2 can be the same or different, and the stirring process and the stimulation application process can be omitted in one or both. The method for moving the decolorizing solution relative to the object to be decolorized in the decolorization process S1 and the rinsing process S2 is also the same.

[0147] (Variation 1-2-2)

[0148] In the first embodiment and the modified examples described, the decolorization step S1 and the rinsing step S2 are performed in different treatment tanks, but they can also be performed in the same treatment tank. For example, after the decolorization step S1, the decolorizing liquid can be discharged from the first treatment tank, and a new decolorizing liquid at a temperature lower than the fiber opening temperature can be injected into the first treatment tank, followed by a stirring step, a stimulation application step, or a relative movement step.

[0149] (Variations 1-2-3)

[0150] Alternatively, if the object to be decolorized is sufficiently decolorized in the decolorization process S1, the rinsing process S2 can be omitted.

[0151] (Variations 1-3)

[0152] The decolorization process S1 and / or rinsing process S2 can be performed multiple times.

[0153] (Variations 1-4)

[0154] In the first embodiment and the modified examples described, the same type of liquid, such as a decolorizing solution with the same composition, is used in the decolorization step S1 and the rinsing step S2. However, decolorizing solutions with different compositions may also be used in the decolorization step S1 and the rinsing step S2.

[0155] For example, the decolorizing solution used in the rinsing step S2 can be a decolorizing solution used in the decolorizing step S1 and containing solvents that dissolve the pigments of disperse dyes at different concentrations.

[0156] Furthermore, when performing multiple decolorization steps S1, the decolorizing solution used in each decolorization step S1 can be the same, or different decolorizing solutions can be used in all decolorization steps S1. Similarly, a decolorizing solution different from the decolorizing solution used in other decolorization steps S1 can be used in at least one decolorization step S1.

[0157] The example of the decolorizing solution can also be applied to situations where multiple rinsing steps S2 are performed, or to situations where both decolorizing steps S1 and rinsing steps S2 are performed multiple times.

[0158] (Variations 1-5)

[0159] Furthermore, the decolorization of disperse dye pigments from the object to be decolorized is accomplished through both the decolorization step S1 and the rinsing step S2, or solely through the decolorization step S1. Therefore, the dehydration step S3 and the drying step S4 can be performed only as needed, or at least one of the dehydration step S3 and the drying step S4 can be omitted.

[0160] For example, if the entire decolorized object is re-dyed by the exhaust dyeing method after decolorization, the dehydration step S3 and the drying step S4 can be omitted. After re-dyeing, only one dehydration step S3 and drying step S4 are performed to dehydrate and dry the decolorized object after re-dyeing.

[0161] (Variations 1-6)

[0162] In the first embodiment and the modified examples described, a case was illustrated where a decolorizing solution was used to decolorize the pigment of a disperse dye that had been dyed or colored into a decolorized object from the polyester or nylon fibers contained in the decolorized object.

[0163] Alternatively, instead of decolorizing disperse dyes, other dyes dyed or colored into the object to be decolorized may be decolorized. Alternatively, instead of decolorizing polyester or nylon fibers, dyes may be decolorized from other fibers capable of retaining the pigments of disperse dyes or other dyes in the interstices of the fiber's molecular chains.

[0164] The decolorizing solution can be any solution that can remove dyes or other pigments that are held in the gaps between the molecular chains of the fiber, thereby decolorizing the fiber.

[0165] Additionally, bleaching solutions may also contain bleaching agents or bleaching solutions for bleaching the pigments of dyes. Here, bleaching the pigment means, for example, removing the pigment by breaking it down, or making the pigment less noticeable by changing its color. Making the pigment less noticeable means, for example, making the color of the fiber close to white, or close to the original color of the fiber.

[0166] Examples of bleaching agents include oxidizing bleaching agents such as chlorine-based bleaching agents or oxygen-based bleaching agents, and reducing bleaching agents.

[0167] Furthermore, when the bleaching solution contains a bleaching agent used to make the pigment less noticeable, the fiber-opening temperature only needs to be the temperature at which the gaps between the molecular chains widen and the molecular chains relax to the point that the active ingredient of the bleaching agent can easily enter the dye pigment present in the gaps between the fiber molecular chains. Therefore, the fiber-opening temperature only needs to be the temperature at which the molecular chains of the fibers contained in the object to be bleached relax.

[0168] (Second Implementation)

[0169] The decolorizing apparatus 100 according to the second embodiment of the present invention will be described. The decolorizing method of the first embodiment can be appropriately performed according to the decolorizing apparatus 100.

[0170] (Structure of decolorization device 100)

[0171] Decolorization device 100 Figure 2 and Figure 3 As shown, it includes a sealed frame 10, a conveying unit 20, a decolorizing unit 30, a rinsing unit 40, an exhaust device 50, a smoke recovery device 60, and a control unit 70.

[0172] The sealed frame 10 houses the conveying section 20, the decolorizing section 30, and the rinsing section 40. The sealed frame 10 is designed to be airtight so that fumes generated from the decolorizing section 30 and the rinsing section 40 will not leak to the outside through paths other than the exhaust device 50. The sealed frame 10 includes an inlet 11 that opens when the decolorized object 1 is moved into the sealed frame 10, and an outlet 12 that opens when the decolorized object 1 is moved out of the sealed frame 10.

[0173] The conveying unit 20 conveys the object to be decolorized 1 through a decolorization process. The conveying unit 20 includes a track 21, a robot base 22 that moves on the track 21, and a robot arm 23 capable of holding the object to be decolorized 1. The track 21 is positioned above a predetermined position where a transport box 5 is placed, spanning above the decolorization unit 30 and the rinsing unit 40, to a predetermined position where a recycling box 6 is placed. The transport box 5 contains the object to be decolorized 1 in a folded state. The recycling box 6 contains the decolorized object 1. The robot arm 23 is mounted on the robot base 22. The robot arm 23 moves along the track 21 together with the robot base 22.

[0174] In the decolorization section 30, the object to be decolorized is cleaned in a treatment tank containing a decolorizing liquid 2 at a specified decolorization temperature using the decolorizing liquid 2.

[0175] Decolorization part 30 Figure 4 As shown, it includes a first processing tank 31, a first storage tank 32, a first supply piping system 33, a first waste liquid tank 34, a first discharge piping system 35, a first impurity removal device 36, and a heating device 37.

[0176] The first processing tank 31 includes an outer cylindrical tank 31a with an opening at the top, an inner cylindrical tank 31b with an opening at the top, and a motor 31c.

[0177] The inner groove 31b is housed within the outer groove 31a. The motor 31c is positioned below the outer groove 31a and the inner groove 31b. The motor 31c drives the inner groove 31b.

[0178] The outer tank 31a and the inner tank 31b are made of stainless steel. The outer tank 31a is in fluid communication with the first storage tank 32 via a first supply piping system 33. In addition, the outer tank 31a is in fluid communication with the first waste liquid tank 34 via a first discharge piping system 35.

[0179] During the decolorization process, the outer tank 31a is filled with decolorizing liquid 2 supplied from the first storage tank 32 via the first supply piping system 33.

[0180] The inner tank 31b has multiple through holes through which the decolorizing liquid 2 passes. During the decolorization process, the inner tank 31b is filled with the decolorizing liquid 2 that enters through the through holes. Furthermore, during the decolorization process, the object to be decolorized 1 is placed into the inner tank 31b by the conveying unit 20.

[0181] Motor 31c has a drive shaft that extends watertight through the center of the bottom of outer tank 31a. The drive shaft is connected to the center of the bottom of inner tank 31b. During the decolorization process, motor 31c causes inner tank 31b to rotate about a vertical axis passing through the center of the bottom of inner tank 31b. As a result, the object to be decolorized 1 and the decolorizing liquid 2 in the first treatment tank 31 are stirred.

[0182] The first storage tank 32 stores the decolorizing solution 2. The decolorizing solution 2 stored in the first storage tank 32 is supplied to the first processing tank 31 via the first supply piping system 33.

[0183] The first supply piping system 33 includes a supply pipe 33a through which the decolorizing liquid 2 is supplied to the first treatment tank 31, a supply valve 33b, and a supply pump 33c for supplying the decolorizing liquid 2.

[0184] The supply valve 33b is a solenoid valve that controls the supply of decolorizing liquid 2 to the first processing tank 31.

[0185] The first waste liquid tank 34 stores the used decolorizing liquid 2 discharged from the first treatment tank 31 via the first discharge piping system 35.

[0186] The first discharge piping system 35 includes a discharge pipe 35a through which the used decolorizing liquid 2 is discharged from the first treatment tank 31, and a discharge valve 35b. The discharge valve 35b is a solenoid valve that controls the discharge of the decolorizing liquid 2 from the first treatment tank 31.

[0187] The first impurity removal device 36 is an activated carbon filter. The first impurity removal device 36 is configured to remove disperse dyes dissolved in the decolorizing liquid 2 discharged from the first treatment tank 31, specifically the pigments of the disperse dyes.

[0188] The first impurity removal device 36 includes a cylindrical activated carbon filter. The activated carbon filter can be replaced as needed or periodically.

[0189] The heating device 37 heats the decolorizing liquid 2 in the first processing tank 31 to the decolorizing temperature. The heating device 37 is an induction heating (IH) heater or a radiation heater. The heating device 37 is arranged around the side of the cylindrical outer tank 31a of the first processing tank 31.

[0190] In the rinsing section 40, the object to be decolorized is rinsed in a treatment tank containing a decolorizing solution at a temperature lower than the specified fiber-opening temperature. For example, the temperature of the decolorizing solution at this time is approximately 20°C, or about 25°C, equivalent to room temperature.

[0191] Rinse section 40 Figure 5 As shown, the system includes a second processing tank 41, a second storage tank 42, a second supply piping system 43, a second waste liquid tank 44, a second discharge piping system 45, and a second impurity removal device 46. The structures of the second processing tank 41, the second storage tank 42, the second supply piping system 43, the second waste liquid tank 44, the second discharge piping system 45, and the second impurity removal device 46 are the same as those of the first processing tank 31, the first storage tank 32, the first supply piping system 33, the first waste liquid tank 34, the first discharge piping system 35, and the first impurity removal device 36, respectively, and therefore, descriptions are omitted.

[0192] like Figure 3 As shown, the exhaust device 50 is configured to discharge the fumes (vapors) of the decolorizing liquid 2 generated from the decolorizing section 30 and the rinsing section 40 to the outside of the sealed frame 10. The exhaust device 50 includes an exhaust pipe 51 and an exhaust fan 52.

[0193] The smoke recovery device 60 is disposed midway in the exhaust duct 51 of the exhaust device 50. The smoke recovery device 60 restores the smoke from the decolorizing liquid 2 passing through the exhaust device 50 to liquid and recovers it. The smoke recovery device 60 includes an electronic cooler that causes condensation on its surface and a recovery tank for recovering the condensate dripping from the surface of the electronic cooler.

[0194] The control unit 70 controls the conveying unit 20, the decolorizing unit 30, the rinsing unit 40, the exhaust device 50, and the smoke recovery device 60 to perform decolorization treatment of the decolorized object 1 and recovery treatment of the decolorizing liquid 2.

[0195] For decolorization and recycling processes, the control unit 70 is configured to include a storage device for storing programs and various data (hard disk, flash memory, etc.), a processor (central processing unit (CPU), etc.) that executes programs stored in the storage device, the main memory of the processor, and various interfaces. The control unit 70 may be, for example, a personal computer.

[0196] (Decolorization treatment)

[0197] First, if the transport box 5, which contains the decolorized object 1 to be decolorized in a folded state, is moved to a designated position outside the sealed frame 10, the following steps are performed by the control unit 70.

[0198] (a) Control the conveying unit 20 to move the robot base 22 above the transport box 5.

[0199] (b) Control the robotic arm 23 to grasp and lift at least one of the decolorized objects 1 in the transport box 5.

[0200] (c) Move the robot base 22 above the first processing tank 31 of the decolorization section 30.

[0201] (d) The decolorized object 1 held by the robotic arm 23 is dropped into the first processing tank 31.

[0202] Thus, the object to be decolorized 1 is placed into the first processing tank 31 of the decolorization unit 30. Furthermore, during the process of moving the robot base 22 above the first processing tank 31, the control unit 70 controls the opening and closing mechanism of the sealed frame 10 to open and close the entrance 11. Thus, the object to be decolorized 1 is moved into the interior of the sealed frame 10 by the robot arm 23.

[0203] In addition, the transport container 5 is moved to the designated location by an operator or an automated supply device such as a self-propelled truck.

[0204] If the object to be decolorized 1 is put into the first processing tank 31, the control unit 70 controls the supply valve 33b and the supply pump 33c of the first supply piping system 33 of the decolorization unit 30 to fill the first processing tank 31 with decolorizing liquid 2.

[0205] Subsequently, the control unit 70 controls the heating device 37 to heat the decolorizing liquid in the first processing tank 31 to a predetermined decolorizing temperature. If the decolorizing liquid is heated to the predetermined decolorizing temperature, the control unit 70 controls the motor 31c of the first processing tank 31 to rotate the inner tank 31b for a predetermined time. As a result, the object to be decolorized 1 and the decolorizing liquid 2 are stirred.

[0206] If a predetermined time has elapsed, the control unit 70 stops the rotation of the inner tank 31b of the first processing tank 31. Then, the control unit 70 performs the following steps to move the decolorized object 1 into the second processing tank 41.

[0207] (a) Control the robot arm 23 to grasp and lift the decolorized object 1 in the first processing tank 31.

[0208] (b) Move the robot base 22 above the second processing tank 41 of the rinsing section 40.

[0209] (c) The object to be decolorized, 1, held by the robotic arm 23, is dropped into the second processing tank 41. Thus, the object to be decolorized, 1, is placed into the second processing tank 41 of the rinsing unit 40.

[0210] If the object to be decolorized 1 is placed into the second treatment tank 41, the control unit 70 controls the supply valve 43b and the supply pump 43c of the second supply piping system 43 of the rinsing unit 40 to fill the second treatment tank 41 with decolorizing liquid 2. At this time, decolorizing liquid 2 at room temperature or ambient temperature is supplied to the second treatment tank 41.

[0211] Subsequently, the control unit 70 controls the motor 41c of the second processing tank 41 to rotate the second inner tank 41b for a predetermined time. As a result, the object to be decolorized 1 and the decolorizing liquid 2 are stirred.

[0212] If the predetermined time has elapsed, the control unit 70 stops the rotation of the second inner tank 41b of the second processing tank 41. Then, the control unit 70 performs the following steps to transport the decolorized object 1 to the recycling bin 6 of the sealed frame 10.

[0213] (a) Control the robot arm 23 to grasp and lift the decolorized object 1 in the second processing tank 41.

[0214] (b) Control the conveying unit 20 to move the robot base 22 above the recycling bin 6 located at a predetermined position outside the enclosed frame 10.

[0215] (c) The decolorized object 1 held by the robotic arm 23 is dropped into the recycling bin 6.

[0216] Thus, the decolorized object 1 is placed into the recycling bin 6. Furthermore, during the process of moving the robot base 22 above the recycling bin 6, the control unit 70 controls the opening and closing mechanism of the sealed frame 10 to open and close the outlet 12. Thus, the decolorized object 1 is moved outside the sealed frame 10 by the robot arm 23.

[0217] Next, the recovery bin 6 containing the decolorized object 1 is transported to the dehydration unit by an operator or an automated supply device such as a self-propelled truck. In the dehydration unit, the decolorized object 1 undergoes dehydration treatment. Subsequently, the decolorized object 1 is transported to the drying unit by an operator or an automated supply device such as a self-propelled truck. In the drying unit, the decolorized object 1 undergoes drying treatment to remove any remaining liquid components (moisture) from it.

[0218] (Recycling)

[0219] In the decolorization process, if the object to be decolorized 1 is taken out from the first processing tank 31, the control unit 70 controls the first discharge piping system 35 of the decolorization unit 30 to discharge the decolorization liquid 2 (used decolorization liquid) in the first processing tank 31 to the first waste liquid tank 34.

[0220] During the process, the used decolorizing solution 2 passes through the first impurity removal device 36. At this time, the disperse dyes contained in the decolorizing solution 2, particularly the pigment components of the dyes, are removed from the decolorizing solution 2. Thus, the decolorizing solution 2, from which the disperse dyes have been removed, is discharged into the first waste liquid tank 34.

[0221] In addition, during the rinsing process, if the decolorized object 1 is removed from the second processing tank 41, the control unit 70 controls the second discharge piping system 45 of the rinsing unit 40 to discharge the decolorizing liquid 2 (used decolorizing liquid) in the second processing tank 41 to the second waste liquid tank 44.

[0222] During the process, the used decolorizing solution 2 passes through the second impurity removal device 46. At this time, the disperse dyes contained in the decolorizing solution 2, especially the pigment components of the dyes, are removed from the decolorizing solution 2. Thus, the decolorizing solution 2, from which the disperse dyes have been removed, is discharged into the first waste liquid tank 34.

[0223] In addition, during the decolorization or rinsing process, the control unit 70 controls the exhaust fan 52 of the exhaust device 50 to draw the fumes of the decolorizing liquid 2 generated from the decolorization unit 30 and the rinsing unit 40 into the exhaust pipe 51 and discharge them to the outside of the sealed frame 10.

[0224] Additionally, during the process, the control unit 70 controls the electronic cooler of the smoke recovery device 60, causing the smoke passing through the exhaust pipe 51 to condense on the surface of the electronic cooler. The condensed decolorizing liquid 2 drips from the surface of the electronic cooler and is ultimately recovered into the recovery tank of the smoke recovery device 60.

[0225] The decolorizing liquid 2 recovered to the first waste liquid tank 34 of the decolorizing section 30, the decolorizing liquid 2 recovered to the second waste liquid tank 44 of the rinsing section 40, and the decolorizing liquid 2 recovered to the recovery tank of the smoke recovery device 60 are all almost free of disperse dyes or impurities. In addition, even if they contain disperse dyes or impurities, they are to the extent that they do not affect the use of the decolorizing liquid 2 for other decolorizing treatments.

[0226] Therefore, the decolorizing liquid 2 recovered to the first waste liquid tank 34, the decolorizing liquid 2 recovered to the second waste liquid tank 44 of the rinsing section 40, and the decolorizing liquid 2 recovered to the recovery tank of the smoke recovery device 60 can be appropriately reused for other decolorization treatments.

[0227] (Effects of the second implementation method)

[0228] The decolorization apparatus of the second embodiment initially achieves the same effect as the decolorization method of the first embodiment.

[0229] Based on this, the decolorization process in the decolorization process S1 and the rinsing process in the rinsing process S2 can be automatically carried out in a closed environment without the aid of human labor.

[0230] During the decolorization and rinsing processes, fumes of decolorizing liquid 2 are generated. These fumes can be a burden on operators or workers. As described above, by conducting the process within a closed environment of the enclosed enclosure 10 to generate the fumes of decolorizing liquid 2, decolorization of the object can be performed without imposing a labor or health burden on the user.

[0231] In addition, the decolorizing liquid 2 recovered to the first waste liquid tank 34 of the decolorizing section 30, the decolorizing liquid 2 recovered to the second waste liquid tank 44 of the rinsing section 40, and the decolorizing liquid 2 recovered to the recovery tank of the smoke recovery device 60 are all free of disperse dyes or impurities. Furthermore, even if they contain disperse dyes or impurities, they are not to the extent that they affect the reuse of the decolorizing liquid 2.

[0232] Therefore, since the recovered decolorizing liquid 2 can be reused for other decolorization or rinsing processes, the environmental and economic burdens are reduced.

[0233] (Variation Example 2-1)

[0234] The structure of the decolorizing apparatus 100, and the structure of the decolorizing section 30, are arbitrary as long as they can perform the decolorizing process S1 of the first embodiment and its variations.

[0235] For example, in the second embodiment, the first processing tank 31 is illustrated as being composed of a cylindrical outer tank 31a and an inner tank 31b. The first processing tank 31 is not limited to the described form.

[0236] For example, the first processing tank 31 may also omit the inner tank 31b and only include the outer tank 31a. Furthermore, the shape of the first processing tank 31 is not limited to a cylindrical shape, but can also be other shapes, such as a rectangle. For example, a deep or shallow box-shaped processing tank with an open top can also be used as the first processing tank 31. Additionally, the material of the first processing tank 31 is not limited to stainless steel, but can also be other materials, such as glass or heat-resistant / solvent-resistant resins.

[0237] Alternatively, the first impurity removal device 36 can be omitted. In this case, the decolorizing liquid 2 accumulated in the first waste liquid tank 34 can be moved outside the sealed frame 10 for regeneration treatment such as filtration or distillation.

[0238] (Variation Example 2-1-1)

[0239] In the second embodiment, an example is given of a case in which the object to be decolorized 1 and the decolorizing liquid 2 are stirred by rotating the inner tank 31b of the first processing tank 31 in the decolorization section 30.

[0240] As long as the pigment of the disperse dye can be removed from the object to be decolorized 1, stirring methods other than the example stirring method can also be used. In addition, mechanical stimulation can also be applied to the object to be decolorized 1 by methods other than stirring.

[0241] For example, as another stirring method, a motor-driven stirring blade can also be used for stirring. In this case, an example is that a motor-driven stirring blade is provided on the bottom surface of the outer tank 31a or the bottom surface of the inner tank 31b of the first processing tank 31.

[0242] In addition, as other stirring methods, magnetic stirrers or electromagnetic stirrers can also be used for stirring. In this case, for example, a magnetic stirrer or electromagnetic stirrer is disposed at the bottom of at least one of the outer tank 31a and the inner tank 31b of the first processing tank 31 for stirring.

[0243] Alternatively, convection can be generated by vibrating the first processing tank 31 (outer tank 31a, inner tank 31b) as a whole or by using a pump.

[0244] Additionally, examples of stimulation devices that apply mechanical stimulation to the object to be decolorized 1 include a vibration device that causes the decolorizing liquid 2 and the object to be decolorized 1 to vibrate together in the first treatment tank 31, an ultrasonic treatment device that performs ultrasonic treatment on the decolorizing liquid 2 and the object to be decolorized 1 together in the first treatment tank 31, and a motor-driven stirring blade that is configured to contact the object to be decolorized 1 in the first treatment tank 31.

[0245] (Variation Example 2-1-2)

[0246] In the second embodiment and the modified examples described therein, decolorization is promoted by stirring the object to be decolorized 1 and the decolorizing liquid 2 in the decolorization section 30, or by applying mechanical stimulation to the object to be decolorized 1 and the decolorizing liquid 2.

[0247] Stimulation can be applied in place of stirring or stimulation, or in addition to this, by causing the decolorizing liquid 2 to move relative to the surface of the object to be decolorized 1.

[0248] For example, in the second embodiment, the decolorizing unit 30 replaces the decolorizing liquid 2 in the first processing tank 31 with new decolorizing liquid 2 each time the decolorization process ends. Decolorization can also be performed while continuously supplying new decolorizing liquid 2 or recycled decolorizing liquid 2 to the first processing tank 31 and discharging excess decolorizing liquid 2 from the first processing tank 31. Alternatively, in this case, the used decolorizing liquid 2 discharged from the first processing tank 31 can be resupplyed to the first processing tank 31. That is, the decolorizing liquid 2 can be recycled. For recycling, for example, the first discharge piping system 35 can be connected to the first storage tank 32 instead of the first waste liquid tank 34, allowing the decolorizing liquid 2 to circulate. Alternatively, another discharge piping system connecting the first processing tank 31 and the first storage tank 32 can be provided to circulate the decolorizing liquid 2.

[0249] In this case, in order to improve the flow of the decolorizing liquid 2, the impurity removal device may not be installed in the first discharge piping system 35 or the newly installed other discharge piping system.

[0250] Alternatively, for example, to induce relative movement of the decolorizing liquid 2 relative to the surface of the object to be decolorized 1, one or more nozzles may be provided to eject the decolorizing liquid 2. In this case, the nozzles may be provided in such a way that a vortex is formed within the first processing tank 31. For example, by providing the nozzles in such a way that the decolorizing liquid 2 is ejected along the normal direction of the outer circumference of the predetermined vortex, a vortex can be formed.

[0251] For example, in the second embodiment, the outer tank 31a of the first processing tank 31 is approximately circular when viewed from above. Therefore, for example, when viewed from above, one or more nozzles for spraying out the decolorizing liquid 2 may be provided at the circular bottom of the outer tank 31a.

[0252] In this case, the decolorizing liquid 2 is supplied from the first supply piping system 33 to the nozzle, and the nozzle is set so that the decolorizing liquid 2 sprayed from the bottom center radially impacts the inner peripheral surface (side surface) of the outer tank 31a at an angle.

[0253] If configured in this way, when the decolorizing liquid 2 is supplied into the first treatment tank 31 through the nozzle, a vortex is generated in the first treatment tank 31, which can cause the decolorizing liquid 2 to move relative to the surface of the object to be decolorized 1.

[0254] Alternatively, when using a box-shaped treatment tank with a deep or shallow top opening as the first treatment tank 31, in order to bring about relative movement of the decolorizing liquid 2 relative to the surface of the object to be decolorized 1, it can be done as follows: The first supply piping system 33 is opened at one end along the long axis of the box-shaped treatment tank, and the first discharge piping system 35 is opened at the other end, so that the decolorizing liquid 2 flows from one end to the other within the treatment tank.

[0255] (Variation Example 2-1-3)

[0256] In the second embodiment and the modified examples described above, in the decolorization section 30, a decolorization solution 2 that has been used and in which impurities, particularly disperse dyes, have been removed can be used instead of a new decolorization solution 2.

[0257] For example, the waste liquid of the decolorizing liquid 2 generated in the decolorizing section 30 can be recovered each time a decolorization process is performed, and impurities can be removed from the recovered decolorizing liquid 2. Then, the decolorizing liquid with impurities removed can also be used in the decolorizing section 30 or the rinsing section 40 in the next decolorization process.

[0258] For example, in order to automate this kind of reuse, such as Figure 6 As shown, in the first supply piping system 33, a supply piping 33d may also be provided connecting the upstream region of the supply pump 33c of the supply piping 33a and the first waste liquid tank 34. In this case, a supply valve 33e may also be provided between the region of the branch of the supply piping 33d in the supply piping 33a and the first storage tank 32, and a supply valve 33f may be provided in the supply piping 33d.

[0259] In this case, when using new decolorizing liquid 2, the supply pump 33c is activated with supply valves 33b and 33e open and supply valve 33f closed, thereby supplying decolorizing liquid 2 from the first storage tank 32 to the first processing tank 31. On the other hand, when using decolorizing liquid 2 after impurities have been removed, the supply pump 33c is activated with supply valves 33b and 33f open and supply valve 33e closed, thereby supplying decolorizing liquid 2 after impurities have been removed from the first waste liquid tank 34 to the first processing tank 31.

[0260] Alternatively, the decolorization process S1 can be configured such that the decolorizing liquid is recycled in the first treatment tank 31, and after impurities are removed from the decolorizing liquid recovered from the first treatment tank 31, it is supplied to the first treatment tank 31.

[0261] For example, in the decolorization process S1, excess decolorizing liquid can be discharged from the first processing tank, impurities can be removed from the discharged decolorizing liquid, and the decolorizing liquid can be re-supplied to the first processing tank.

[0262] (Variation 2-1-4)

[0263] Alternatively, for example, the decolorizing unit 30 may replace the first processing tank 31 and include a spraying device for spraying the decolorizing liquid 2 onto the object to be decolorized 1. In this case, the spraying device sprays the decolorizing liquid at the decolorizing temperature onto the object to be decolorized in either a liquid or gaseous state.

[0264] Examples of spraying devices include steam irons or atomizers, particularly high-pressure steam irons or high-pressure atomizers. In this case, the first supply piping system 33 is connected to the spraying device, and the first discharge piping system 35 is connected to the waste liquid outlet under the bottom plate of the sealed frame 10 instead of being connected to the first treatment tank 31. For example, the decolorizing liquid 2 is sprayed from the spraying device in liquid or gaseous form onto the decolorized object 1, which is held by the robotic arm 23 of the conveying unit 20. Droplets of the decolorizing liquid 2 dripping from the decolorized object 1 are discarded from the waste liquid outlet and stored in the first waste liquid tank 34.

[0265] (Variation Example 2-1-5)

[0266] In the second embodiment and the modified examples described, the decolorizing section 30 is configured to stir the object to be decolorized 1 and the decolorizing liquid 2, or to apply mechanical stimulation to the object to be decolorized 1, or to move the decolorizing liquid 2 relative to the object to be decolorized 1. This structure may also be omitted. In this case, when the decolorizing section 30 performs the heating step of the decolorizing process S1, compared to the case with these omitted structures, the decolorizing temperature can be higher, and / or the contact time between the object to be decolorized 1 and the decolorizing liquid 2 can be longer.

[0267] (Variation Example 2-1-6)

[0268] In the second embodiment and the modified examples described above, a case using a first impurity removal device 36 is illustrated. When removing impurities from the used decolorizing liquid 2, the first impurity removal device 36 only needs to have the capability to remove disperse dyes or pigments of disperse dyes contained in the decolorizing liquid 2 to a degree that allows it to be reused in the decolorization process. Therefore, a filtration device utilizing activated carbon, or a distillation device that removes impurities by distillation, etc., can be used.

[0269] (Variation Example 2-1-7)

[0270] In the second embodiment and the aforementioned variations, a case using a heating device 37 is illustrated. The structure of the heating device 37 is arbitrary as long as it can heat the decolorizing liquid 2 to the decolorizing temperature. In addition to electromagnetic induction heating (IH) heaters, radiation heaters, etc., it can also be, for example, an oil bath or an immersion heater. Furthermore, the heating device 37 can replace the first processing tank 31 or a spray device, or it can also be configured to heat the first storage tank 32.

[0271] (Variation Example 2-1-8)

[0272] In the second embodiment and the modified examples described above, a cover configured to open and close automatically may be provided in the first processing tank 31 of the decolorization section 30. The cover opens when the object to be decolorized 1 is placed into the first processing tank 31 and closes until the decolorization process of the decolorization section 30 is completed. This reduces the amount of smoke leaking from the first processing tank 31 of the decolorization section 30.

[0273] (Variation Example 2-2)

[0274] The structure of the rinsing unit 40 is arbitrary as long as it can perform the rinsing process S2 of the first embodiment and its variations.

[0275] (Variation Example 2-2-1)

[0276] Except for the operating temperature of the decolorizing solution and the presence or absence of a heating device 37, the rinsing section 40 can be configured in the same way as the decolorizing section 30. Therefore, except for the operating temperature of the decolorizing solution and the presence or absence of a heating device 37, the aforementioned modifications to the decolorizing section 30 can also be applied to the rinsing section 40.

[0277] Furthermore, in the rinsing section 40, the structures for stirring the object to be decolorized 1 and the decolorizing liquid 2, applying mechanical stimulation to the object to be decolorized 1, or moving the decolorizing liquid 2 relative to the object to be decolorized 1 can be omitted. If these structures are omitted, during the cooling process of the rinsing step S2 in the rinsing section 40, the contact time between the object to be decolorized 1 and the decolorizing liquid 2 can be longer than if the omitted structures are implemented.

[0278] Furthermore, the methods for applying mechanical stimulation to the object to be decolorized 1 in the decolorization section 30 and the rinsing section 40 can be the same or different. It is also possible to omit, in at least one of the decolorization section 30 and the rinsing section 40, the structures for stirring the object to be decolorized 1 and the decolorizing liquid 2, applying mechanical stimulation to the object to be decolorized 1, or causing the decolorizing liquid 2 to move relative to the object to be decolorized 1.

[0279] (Variation Example 2-2-2)

[0280] Additionally, the rinsing unit 40 may also include a cooling device for cooling at least one of the second processing tank 41 and the second storage tank 42. The material 1 to be decolored, when immersed in the decolorizing liquid within the decolorizing unit 30, becomes hot. Therefore, if the material 1 to be decolored is frequently immersed from the decolorizing unit 30 into the rinsing unit 40, the temperature of the decolorizing liquid 2 within the rinsing unit 40 may become high. By including a cooling device, the possibility that the temperature of the decolorizing liquid 2 within the rinsing unit 40 may exceed the fiber opening temperature can be reduced.

[0281] Therefore, the decolorization efficiency in the rinsing section 40 can be maintained.

[0282] (Variation Example 2-2-3)

[0283] It can replace the rinsing section 40 or, in addition, perform the rinsing process S2 in the decolorization section 30.

[0284] For example, after the decolorization process S1 is performed in the decolorization section 30, the decolorizing liquid 2 is discharged from the first processing tank 31, and then a decolorizing liquid at a temperature lower than the fiber opening temperature is supplied to the decolorization section 30 from the first storage tank 32. Then, a stirring process, a stimulation application process, or a relative movement process may be performed in the decolorization section 30 filled with a decolorizing liquid at a temperature lower than the fiber opening temperature.

[0285] (Variation 2-1-4)

[0286] Alternatively, if the object to be decolorized is sufficiently decolorized in the decolorization section 30, the rinsing section 40 may be omitted.

[0287] (Variations 2-3)

[0288] Multiple decolorization sections 30 and / or rinsing sections 40 may also be provided. For example, to increase the throughput per unit time, the decolorization process S1 may be performed in parallel in multiple decolorization sections 30. To make the decolorization more complete, the object to be decolorized 1 may pass through multiple decolorization sections 30 sequentially, and the decolorization process S1 may be performed in each decolorization section 30. The same applies to the rinsing section 40.

[0289] (Variations 2-4)

[0290] In the second embodiment and the modified examples described above, a case is illustrated where the same composition of the decolorizing liquid 2 is used in both the decolorizing section 30 and the rinsing section 40. However, decolorizing liquids 2 with different compositions may also be used in the decolorizing section 30 and the rinsing section 40. For example, the decolorizing liquid used in the rinsing section 40 may be a decolorizing liquid used in the decolorizing section 30 that contains a solvent at a different concentration to dissolve the pigment of the disperse dye.

[0291] Furthermore, when multiple decolorizing sections 30 are provided, the decolorizing liquid 2 used in each decolorizing section 30 can be all the same, or a decolorizing liquid 2 with a different composition can be used in at least one decolorizing section 30. The same applies when multiple rinsing sections 40 are provided, or when both multiple decolorizing sections 30 and rinsing sections 40 are provided.

[0292] (Variations 2-5)

[0293] The structure of the sealed frame 10 can be arbitrary as long as it is designed to be sealed so that the fumes generated from the decolorization section 30 and the rinsing section 40 do not leak to the outside through paths other than the prescribed path such as the exhaust device 50.

[0294] For example, air curtains can be installed at the inlet 11 and outlet 12 of the enclosed frame 10. This prevents fumes from leaking from the inlet 11 and outlet 12 when the conveying section 20 transports the decolorized object 1. Furthermore, even if leakage occurs, the amount of leakage can be suppressed.

[0295] (Variations 2-6)

[0296] It can replace the sealed frame 10, and such as Figure 7 As shown, a cover 80 is provided to cover the opening for emitting smoke in the decolorizing section 30 and the rinsing section 40. This structure reduces the amount of smoke diffusing into the surrounding environment and automatically performs the decolorizing process S1 and the rinsing process S2, which generate potentially harmful smoke from the decolorizing liquid 2, without human intervention. Therefore, decolorization of the object can be performed without burdening the user.

[0297] In addition, in order to shorten the distance between the cover 80 and the openings for emitting smoke in the decolorizing section 30 and the rinsing section 40, such as Figure 7 As shown, the conveying section 20 can also be configured such that it is positioned on the side of the cover 80 and enters the decolorizing section 30 and the rinsing section 40 through the gap between the cover 80 and the opening.

[0298] Alternatively, the cover 80 may be individually disposed above the decolorization section 30, the rinsing section 40, or other devices that may generate harmful substances.

[0299] (Variations 2-7)

[0300] The structure of the exhaust device 50 is arbitrary as long as it can exhaust the fumes of the decolorizing liquid 2 generated from the decolorizing section 30 and the rinsing section 40.

[0301] (Variations 2-8)

[0302] The structure of the smoke recovery device 60 is arbitrary as long as it can restore the smoke from the decolorizing liquid 2 passing through the exhaust device 50 to liquid form and recover it. For example, if the smoke from the decolorizing liquid 2 condenses on the inner surface of the exhaust pipe 51 of the exhaust device 50, the bottom of a portion of the horizontally extending exhaust pipe 51 can be formed into a funnel shape, and the top of the funnel can be connected to a recovery device such as a recovery bottle via a drain pipe. In this case, the smoke restored to liquid form can be recovered into the recovery device.

[0303] (Variations 2-9)

[0304] At least one of a liquid removal device and a drying device may also be provided inside the sealed frame 10 or below the cover 80. In addition, other devices required for pre-treatment or post-treatment of decolorization may also be provided inside the sealed frame 10 or below the cover 80.

[0305] (Variation Example 2-10)

[0306] The structure of the conveying unit 20 can be any structure that allows for the input and output of the decolorizing object 1 relative to the decolorizing unit 30 and the rinsing unit 40. For example, it can also be designed as a structure that allows the workpiece holding mechanism mounted on the turntable to move in the vertical direction, similar to a tenter frame clamp.

[0307] Alternatively, if a liquid removal device, a drying device, or other device is installed inside the sealed frame 10 or below the cover 80, the conveying unit 20 may also be configured to convey the decolorized object 1 to these devices and hang the decolorized object 1 on these devices.

[0308] (Variation Example 2-11)

[0309] The decolorization device 100 is constructed to explosion-proof specifications.

[0310] (Example 1)

[0311] Using a direct sublimation printing apparatus (Mimaki Engineering, Tiger 600-1800TS), test patterns for a color chart were printed on a 60 cm × 60 cm polyester fabric (Tropical) using disperse dyes (Mimaki Engineering, Sb510). The polyester fabric was immersed in Newsolve UC in a bath and heated to 160°C for 2 minutes while stirring (100 rpm). Then, the polyester fabric was immersed in another beaker of Newsolve UC (main components: dimethyl succinate, dimethyl glutarate, and dimethyl adipate) and heated to 160°C for 10 seconds while stirring (100 rpm). Finally, the polyester fabric was removed, dehydrated, and dried. The test pattern on the decolorized polyester fabric had completely disappeared, and there was no deterioration in feel or shrinkage.

[0312] (Example 2)

[0313] Except for the use of diethylene glycol monoethyl ether acetate instead of Newsolve UC, the decolorization process was performed in the same manner as in Example 1. In this case, the test pattern on the decolorized polyester fabric also completely disappeared, and no deterioration in hand feel or shrinkage occurred.

[0314] (Example 3)

[0315] Except for the use of 3-methoxy-N,N-dimethylpropionamide instead of Newsolve UC, the decolorization treatment was performed in the same manner as in Example 1. In this case, the test pattern on the decolorized polyester fabric also completely disappeared, and no deterioration in hand feel or shrinkage occurred.

[0316] Various embodiments and modifications can be made to this invention without departing from its broad spirit and scope. Furthermore, the embodiments described are illustrative and do not limit the scope of the invention. That is, the scope of the invention is indicated by the claims rather than the embodiments. Moreover, all modifications made within the scope of the claims and their equivalents are considered to be within the scope of the invention.

[0317] Explanation of icon numbers

[0318] 1: Object to be decolorized

[0319] 2: Decolorizing solution

[0320] 5: Shipping box

[0321] 6: Recycling bin

[0322] 10: Enclosed frame

[0323] 11: Entrance

[0324] 12: Exports

[0325] 20: Transport Department

[0326] 21: Track

[0327] 22: Robot Base

[0328] 23: Robotic Arm

[0329] 30: Decolorization section

[0330] 31: First processing tank

[0331] 32: First storage tank

[0332] 33: First supply piping system

[0333] 33a: First supply piping

[0334] 33b, 33d: Supply valves

[0335] 33c, 33e, 33f: Supply pumps

[0336] 34: First waste liquid tank

[0337] 35: First discharge piping system

[0338] 35a: Discharge piping

[0339] 35b: Discharge valve

[0340] 36: First impurity removal device

[0341] 37: Heating device

[0342] 40: Rinsing Department

[0343] 41: Second processing tank

[0344] 42: Second storage tank

[0345] 43: Secondary supply piping system

[0346] 43a: Supply piping

[0347] 43b: Supply valve

[0348] 43c: Supply pump

[0349] 44: Second waste liquid tank

[0350] 45: Second Discharge Piping System

[0351] 45a: Discharge piping

[0352] 45b: Discharge valve

[0353] 46: Second impurity removal device

[0354] 50: Exhaust device

[0355] 51: Exhaust pipe

[0356] 52: Exhaust fan

[0357] 60: Smoke recovery device

[0358] 70: Control Department

[0359] 80: Cover

[0360] 100: Decolorization device

Claims

1. A decolorization method for decolorizing a material containing fibers dyed or colored with a dye, wherein, The pigment is retained in the gaps between the molecular chains of the fiber. The decolorization method includes a decolorization step in which the object to be decolorized is cleaned with a first decolorizing solution. The decolorization temperature of the first decolorizing solution is above the fiber-opening temperature, which is the temperature at which the molecular chains relax to the point that the pigment is released from the gaps between the molecular chains of the fibers contained in the object to be decolorized.

2. The decolorization method according to claim 1, wherein... The dye is a disperse dye. The fiber is a fiber that can be dyed or colored by the disperse dye.

3. The decolorization method according to claim 1, wherein... In the decolorization process, the fibers are brought into contact with the first decolorizing liquid at the decolorization temperature in a processing tank.

4. The decolorization method according to claim 3, wherein In the decolorization process, the object to be decolorized is placed into the first decolorization liquid in the treatment tank containing the first decolorization liquid heated to the decolorization temperature.

5. The decolorization method according to claim 3, wherein... In the decolorization process, the first decolorizing liquid is heated to the decolorization temperature in the treatment tank containing the object to be decolorized and the first decolorizing liquid at a temperature lower than the decolorization temperature.

6. The decolorization method according to claim 3, wherein... The decolorization process includes a stimulation application process, in which mechanical stimulation is applied to the decolorized object after or during contact between the first decolorizing liquid and the fiber.

7. The decolorization method according to claim 6, wherein... The stimulation application process includes any one of the following steps: stirring the first decolorizing liquid containing the decolorized object in the treatment tank, a vibration process, and an ultrasonic treatment process.

8. The decolorization method according to claim 3, wherein The decolorization process is carried out simultaneously by supplying new or recycled first decolorizing liquid to the treatment tank and discharging excess first decolorizing liquid from the treatment tank.

9. The decolorization method according to claim 1, wherein... The decolorization process includes the step of spraying the first decolorizing liquid onto the object to be decolorized in liquid or gas form at the decolorization temperature.

10. The decolorization method according to claim 1, It also includes a rinsing step after the decolorization step, in which a second decolorizing solution for decolorizing the pigment is brought into contact with the object to be decolorized.

11. The decolorization method according to claim 10, wherein... The second decolorizing solution is a liquid of the same type as the first decolorizing solution.

12. The decolorization method according to any one of claims 1 to 11, It also includes a dehydration step of removing the first decolorizing liquid from the decolorized object, and a drying step of drying the decolorized object.

13. The decolorization method according to claim 1, wherein... The fiber includes at least one of polyester fiber and nylon fiber.

14. The decolorization method according to claim 1, wherein... The decolorization temperature is lower than the boiling point of the first decolorization solution.

15. A decolorizing apparatus for decolorizing a dye from a material containing fibers dyed or colored with a dye, the decolorizing apparatus comprising: The decolorization section washes the object to be decolorized with a first decolorizing solution for decolorizing the dye. The decolorization temperature of the first decolorizing solution is above the fiber-opening temperature, which is the temperature at which the molecular chains relax to the point that the pigment is released from the gaps between the molecular chains of the fibers contained in the object to be decolorized. An exhaust device is used to exhaust the fumes from the first decolorizing liquid generated in the decolorizing section; A smoke recovery device that restores the smoke to a liquid state and recycles it; and The conveying unit moves the decolorized object into the decolorization unit and moves the decolorized object out of the decolorization unit after decolorization.

16. The decolorizing apparatus according to claim 15, It also includes a sealed frame that houses the decolorizing section and the conveying section. The exhaust device is installed in the sealed frame to expel the smoke from the inside of the sealed frame to the outside.

17. The decolorizing apparatus according to claim 15, It also includes a cover, which is disposed above and covers the opening for venting the smoke from the decolorizing section. The exhaust device is mounted on the cover.

18. The decolorizing apparatus according to claim 15, wherein The decolorization section includes a first processing tank for loading the first decolorizing liquid, a first storage tank for storing the first decolorizing liquid and supplying the first decolorizing liquid to the first processing tank, and a heating device for heating the first decolorizing liquid in the first processing tank or the first storage tank to the decolorization temperature.

19. The decolorizing apparatus according to claim 18, wherein The decolorization section includes a stimulation device that applies mechanical stimulation to the object to be decolorized.

20. The decolorizing apparatus according to claim 19, wherein The stimulation device includes at least one of the following: a stirring device for stirring the decolorized object and the first decolorizing liquid in the first treatment tank; a vibration device for agitating the first decolorizing liquid and the decolorized object together in the first treatment tank; an ultrasonic treatment device for ultrasonically treating the first decolorizing liquid and the decolorized object together in the first treatment tank; and a stirring blade configured to contact the decolorized object in the first treatment tank.

21. The decolorizing apparatus according to claim 18, wherein The decolorization unit supplies the first decolorizing liquid from the first storage tank to the first processing tank and discharges excess first decolorizing liquid from the first processing tank, while simultaneously cleaning the object to be decolorized using the first decolorizing liquid.

22. The decolorizing apparatus according to claim 15, wherein The decolorization section includes a spraying device that sprays the first decolorizing liquid at the decolorization temperature onto the object to be decolorized in the form of a liquid or a gas.

23. The decolorizing apparatus according to claim 15, wherein The decolorization section further cleans the decolorized object that has been decolorized by the first decolorization solution with a second decolorization solution. The temperature of the second decolorization solution is lower than the fiber opening temperature and it decolorizes the dye.

24. The decolorizing apparatus according to claim 15, It also includes a rinsing section, which cleans the material to be decolorized in the decolorization section with a second decolorizing solution. The temperature of the second decolorizing solution is lower than the fiber opening temperature and it decolorizes the dye. The conveying section transports the decolorized object from the decolorization section to the rinsing section.

25. The decolorizing apparatus according to claim 15, It also includes an impurity removal device that removes the dye from the used first decolorizing liquid discharged from the decolorizing section.

26. The decolorizing apparatus according to any one of claims 15 to 25, further comprising: A dehydration device for removing liquid from the decolorized object, and A drying apparatus for drying the decolorized object.

27. The decolorizing apparatus according to claim 15, It is constructed to explosion-proof specifications.

28. The decolorizing apparatus according to claim 15, wherein the fiber comprises at least one of polyester fiber and nylon fiber.

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