JPH08158265A - Method for recovering textile product - Google Patents

Abstract

PURPOSE: To easily recover and recycle a textile product by hydrolyzingly removing the cellulose-based fibers alone from a polyester textile product blended with the cellulose-based fibers. CONSTITUTION: A blended textile product comprising polyester fibers/cellulose- based fibers is dipped in an aqueous solution at 30-60 deg.C containing cellulase and adjusted to pH 4-6 followed by agitation to hydrolyzingly remove the cellulose-based fibers alone without damaging the polyester fibers. In this method, combined use of a surfactant further facilitates polyester fiber recovery and recycling. This method can also remove stains and impurities from the textile product, easily pelletize the resultant polyester fibers, and facilitate hydrolyzing the polyester fibers with an alkali agent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering and regenerating textile products such as clothes, and particularly for efficiently recovering and regenerating the polyester fiber-based products which are used in large amounts.

[0002]

2. Description of the Related Art Polyester fiber-based products, whose main component is polyester fiber, which is a synthetic fiber made of polyester resin, are hardly recovered and recycled, and unnecessary polyester fiber-based products are discarded. Is the current situation.

A molded product made of a polyester resin such as a PET bottle is partially subjected to a recovery / regeneration treatment. As a treatment method, the polyester resin component washed and separated from the polyester resin molded product is cut or melted. It is often made into resin pellets and reused.

Further, there is an alkali hydrolysis treatment as a recovery and regeneration treatment of the polyester resin product. In this alkali hydrolysis treatment, the polyester resin component is hydrolyzed with an alkali having a pH of about 9 to 14, and the polyester is treated with an alkali metal salt of terephthalic acid or ethylene. Separated and decomposed into glycol,
It is recovered as useful substances such as terephthalic acid.

Even a polyester product made of the same polyethylene terephthalate-based synthetic resin, a polyester fiber product is rarely composed of only polyester fibers, and is often used in combination with other fibers. Therefore, those fibers, especially natural fiber components that are not synthetic fibers, often hinder the recycling process, and cannot be recovered and recycled like polyester resin molded products.

Even in the case of a polyester fiber type product, if the other fiber components can be separated and only the polyester fiber component can be taken out, it becomes possible to pelletize the resin in the same manner as the polyester resin molded product, and to carry out the alkali hydrolysis treatment. Even in such cases, generation of extraneous impurities is small and high efficiency can be expected, and extra wastes are less likely to be produced even in the case of gasification and oilification.

For polyester fiber type products such as clothes,
In order to improve the texture and ensure hygroscopicity, it is mixed with other fibers, mixed and woven, or the fibers used are different depending on the part,
It is often used in combination with other fibers, and as a fiber to be combined with a polyester fiber, it is often combined with a cotton fiber which is a cellulosic fiber, and especially in clothes, it is preferably combined with a cotton fiber.

[0008]

In a polyester fiber-based product such as clothes, the polyester resin component is not directly recovered, but if only the polyester fiber component can be taken out before the recovery process, the subsequent recovery process is satisfactory. Although it can be done well, it is difficult to separate only the polyester fiber component from the polyester fiber product, especially with polyester fiber mixed and woven with other fibers, it is not possible to use physical means and it becomes unnecessary. There is a strong demand for a method of simply separating only the polyester fiber component from a polyester fiber-based product.

Polyester fiber has excellent properties as a fiber, but since it has a hard texture and poor hygroscopicity only with a polyester component, it can be used by mixing with a cotton fiber which is a cellulosic fiber. In many cases, polyester fiber is used for the outer surface of clothes, and cotton is often used for the lining, and it is often combined with cotton fiber.

[0010]

In the present invention, a cellulose component such as cotton fiber, which is used as a mixture in a polyester fiber type product, is decomposed and separated by a cellulase enzyme without affecting the polyester component to obtain a polyester fiber type product. The cellulosic fiber component is removed from the product to separate only the polyester fiber component.

A fiber product is placed in a reaction vessel containing an aqueous solution containing a cellulase enzyme, and the cellulosic fiber is hydrolyzed by the cellulase enzyme to decompose cellulose into glucose and reducing sugars. The cellulase enzyme is a cellulose fiber. Since most of them enter the interior slowly and show maximum activity around pH 5, it is better to acidify the aqueous solution containing cellulase enzyme with pH 4 to 6 with inorganic acids such as hydrochloric acid and acetic acid, and organic acids. By doing so, it is possible to expect the effect of swelling and decomposing cellulose fibers by the acid as well as the effect of permeation of the aqueous solution into the fiber interior, and also the effect of washing with acid, so that the effect of separating dirt and oil from the fiber product can be obtained .

If a surfactant is added to the aqueous solution containing the cellulase enzyme, the cellulase enzyme can be penetrated into the inside of the cellulose fiber and the dirt and oil of the textile product can be separated, and further applied to the textile product. Since it is possible to remove the frequently used waterproof surface treatment and gloss surface treatment, cellulase enzyme can easily reach the cellulose content, and the surfactant used in this case is preferably one that acts in a neutral or weakly acidic atmosphere. The resin is decomposed by alkali and strong acid, but is not affected by weak acidity, and is also resistant to hydrocarbon solvents, so that the polyester fiber is not decomposed by a neutral or weakly acidic surfactant.

A reaction vessel containing an aqueous solution containing a cellulase enzyme is preferably equipped with a stirring device such as a stirring blade so that the surface of the cellulose fiber decomposed by the cellulase enzyme is rapidly dissolved in the aqueous solution to allow the reaction of the cellulase enzyme. Will reach the inside of the fiber faster, and also in this case, the reaction of the cellulase enzyme will reach the inside of the cellulose fiber more quickly if an acid or a surfactant is used in combination.

If the cellulose fiber component can be separated from the polyester fiber-based product, the amount of impurities generated during the alkaline hydrolysis treatment of the remaining polyester fiber is reduced,
In addition, even when melted into resin pellets, the proportion of the polyester resin component increases, and if the polyester fiber-based product can be separated into oil, dirt, and surface treatment, recovery and regeneration of the polyester resin component from the polyester fiber-based product will be more effective. You can do it.

[0015]

[Function] An enzyme that hydrolyzes a cellulose component such as cotton is well known as a cellulase enzyme, and is used for modifying and organizing cotton fiber and the like. Cellulase enzymes such as Trichoderma spp. And Aspergillus spp. There are various commercially available products, for example, Onozuka R-10 (manufactured by Yakult) as a genus of Trichoderma.

Since many of the cellulosic fibers mixed and woven with polyester fibers as polyester fiber-based products are made of cotton, and are often combined with a portion constituted by cotton to make products such as clothes, they are decomposed by cellulase enzyme. The target is mainly cotton fibers, but other cellulosic fibers such as regenerated cellulose fibers and hemp can also be decomposed.

As the polyester fiber-based product, the fabric of textile products such as clothes contains 50% or more of the polyester component, or the polyester fiber fabric and the cellulose fiber fabric are combined, but the cellulase enzyme is only the cellulose component. Since it does not affect the polyester component, even the blended fiber of polyester and cotton can decompose and separate only the cellulose component of the fiber yarn, and the polyester fiber part can be added to the aqueous solution containing the cellulase enzyme. Since it does not melt or disperse and always remains in the form of dough or thread, it is easy to take out the polyester fiber component after the completion of the cellulase enzyme treatment.

When the cellulase enzyme to be used is used as an acidic aqueous solution of cellulase enzyme at an acidity of pH 4 to 6, the polyester fiber has acid resistance and thus is not affected by the acidity of pH 4 to 6, but stains attached to the textile product and The oil and surface treatment components can be decomposed acidic, and the acid has an osmotic power, so that the aqueous solution quickly penetrates into the fiber, and the cellulase enzyme, which is difficult to penetrate into the fiber, is also introduced into the cellulose fiber.

If a surfactant such as soap or higher alcohol is added to the aqueous solution containing the cellulase enzyme, the cellulase enzyme can quickly permeate into the fiber, and at the same time, the oil component due to the surfactant can be obtained. As a result, it is possible to separate and decompose dirt and surface treatment components adhering to the polyester fiber.

If a stirring device such as a stirring blade is provided in the reaction tank containing the aqueous solution containing the cellulase enzyme, the fiber product in the aqueous solution can be fluidized and moved, and the cellulose content decomposed by the cellulase enzyme can be rapidly dissolved in the aqueous solution. The stains and oils that have been melted and separated and decomposed can be quickly separated from the fiber product, easily reach the cellulose fiber before the cellulase enzyme is decomposed, and replace the cellulase enzyme with the aqueous solution that permeates the inside of the fiber. Also help.

[0021]

EXAMPLE FIG. 1 is a process diagram showing an example of a method for recovering and regenerating a polyester fiber product according to the present invention, in which a reaction tank in which an unnecessary polyester fiber product 1 contains an aqueous solution containing a cellulase enzyme. 2 and react with stirring blade 3 for several hours to several days while stirring to remove the cellulosic fiber content by hydrolysis with a cellulase enzyme, and remove the polyester fiber remaining as a solid from the reaction tank,
The polyester hot water 4 removed and dehydrated is washed in a water washing tank 5.

The polyester fibers taken out from the water washing tank 5 and dehydrated and dried have not only the cellulose fibers removed but also a lot of stains and surface treatments. Since most of the content is in the form of pellets, pelletization can be performed as in the case of recovery of polyester resin molded products, and generation of extraneous impurities is reduced even when hydrolysis is performed with an alkali.

The aqueous solution containing the cellulase enzyme in the reaction tank 2 contains about 2 to 10% of the cellulase enzyme in the water, but since the purpose is to decompose and remove the cellulose fiber content, the reaction is so strictly controlled. It is not necessary to carry out the cellulase enzymatic reaction until the cellulose fiber content is removed from the polyester fiber-based product put in the reaction tank 2, and the polyester fiber itself is decomposed or melted even for a long time reaction. Never

The cellulase enzyme will die in a high temperature atmosphere,
The reaction is slow at low temperature, and in order to improve the function of the acidic components such as acetic acid and the surfactant to be used together, the temperature of the cellulase enzyme aqueous solution in the reaction tank 2 should be 30 to 60 degrees Celsius because the temperature should be higher to some extent. In order to maintain the continuity of the reaction, the hydrolyzed cellulose needs to be rapidly separated from the surface of the fiber product, and the aqueous solution that has penetrated inside the fiber is replaced with the cellulase enzyme that works from outside the fiber. In addition, it is necessary to flow and move the fiber product in the aqueous solution, and the stirring blade 3 as stirring means is provided in advance.

The acid to be added to the aqueous solution containing the cellulase enzyme may be an inorganic acid, but if acetic acid, which is an organic acid, is used, the function of the cellulase enzyme is less likely to be inhibited and the pH is adjusted to pH 4 which is convenient for the activity of the cellulase enzyme. It is easy to adjust to 6, and the surfactant to be added to the aqueous solution is added in an amount of about 1 to 10 g per liter, but a surfactant that works well in acidity and does not inhibit the action of cellulase enzyme is selected.

Cellulose hydrolyzed by the cellulase enzyme becomes glucose and saccharides, and can be easily reused by a usual method.

[0027]

EFFECTS OF THE INVENTION According to the present invention, since the cellulose component such as cotton fiber can be easily separated and decomposed from the unnecessary polyester fiber-based product, the polyester resin is used in the form of fiber mixed with the cellulose fiber. Even if only polyester fibers can be separated and taken out, pelletization is possible like other polyester resin product regeneration and recovery methods, and when alkaline hydrolysis is performed, the generation of impurities is reduced and useful components It becomes easy to collect and reuse.

Since the cellulose component such as cotton fiber can be reused after being decomposed, the polyester fiber and the cellulose fiber component can be recovered and recycled without waste from the polyester fiber product.

[Brief description of drawings]

FIG. 1 is a process diagram of a method for collecting a textile product according to an embodiment of the present invention.

[Explanation of symbols]

 1, unnecessary polyester fiber product 2, reaction tank 3, stirring blade 4, polyester fiber 5, water washing tank

Claims (4)

[Claims] 1. A recovery of a fiber product characterized in that a fiber product obtained by mixing polyester fiber and cellulosic fiber is treated with an aqueous solution containing a cellulase enzyme to hydrolyze a cellulose component to separate the fiber from the polyester fiber. Method 2. The method for recovering a textile product according to claim 1, wherein an acid is added to an aqueous solution containing a cellulase enzyme, and the cellulase enzyme treatment is performed with an acidic aqueous solution having a pH of 4 to 6. 3. The method for recovering a textile product according to claim 1, wherein a surfactant is added to the aqueous solution containing the cellulase enzyme. 4. An aqueous solution containing a cellulase enzyme is added to 30.
The method for recovering a textile product according to claim 1, wherein the cellulase enzyme treatment is carried out in a reaction tank having a stirring means at a temperature of -60 ° C.