JPS63236538A - Preparation of water retentive base material - Google Patents

Abstract

PURPOSE:To effectively utilize resources by solving an urban garbage problem caused by a used diaper, by applying grinding treatment to the used diaper until the size of the ground particle thereof becomes the size of the polymer water retentive material contained in the used diaper or less. CONSTITUTION:A disposable diaper contains 3-20wt.% of a polymer water retentive material in a dry state before use and the polymer water retentive material can absorb water in quantity reaching several hundreds - thousand times its own wt. but the absorbing capacity thereof is lowered to about 50-60 times its own wt. by filth such as urine. Therefore, the used diaper is discarded while the latent absorbing capacity thereof is left. The used diaper is ground until the size of the ground particle thereof becomes the size of the polymer water retentive material contained in the used diaper or less to obtain a water retentive base material. Since this water retentive base material contains the polymer water retentive material whose water absorbability is restored, it can be utilized as water absorbing and retentive material.

Description

[Detailed Description of the Invention] Purpose of the Invention [Field of Industrial Application] The present invention relates to a method for producing a water-retaining base material, and more specifically, it relates to a method for manufacturing a water-retaining base material, and more specifically, a method for producing a water-retaining base material using a used diaper containing a polymeric water-retaining material. , relates to a method for producing a water-retaining base material that absorbs and retains water.

[Prior Art] Disposable disposable diapers are easy to handle, so their use as diapers for infants and the elderly has rapidly increased in recent years.

Some of these disposable disposable diapers use natural materials such as cotton and bulbs as water absorbing materials, but those that use polymeric water retaining materials have a much greater water absorbing capacity and high water retention ability. It has the advantage of requiring less frequent replacement, and is used in large quantities despite being relatively expensive.

Polymer water-retaining materials used in disposable diapers can be classified into starch, cellulose, and
Polyacrylic acid-based, poval-based, polyoxyethylene-based, etc. are used, and when classified in terms of shape, granular, film-like, etc. are used.

[Problems to be Solved by the Invention] Currently, such disposable diapers are thrown away as municipal waste after use and are collected together with other garbage. Such handling does not pose a problem while the amount of used disposable diapers generated is still small, but as the amount of used disposable diapers increases further in the future, hygiene and other problems may become apparent.

For this reason, sorting treatment and separate collection after collection are being considered, but in any case, it is thought that a method to appropriately dispose of large quantities of such used disposable diapers will ultimately be needed in the future.

In addition, diapers containing polymeric water-retaining materials are characterized by their high water absorption capacity, but when the material to be absorbed is urine or other waste, the absorption capacity ranges from a fraction of that of water to several It is said that it is only one-tenth of the total. Therefore, relatively expensive polymeric water retaining materials are discarded without fully utilizing their capabilities, resulting in a waste of resources.

In view of the above-mentioned situation, the present inventors have conducted various studies on how to effectively utilize used disposable diapers, and have developed a method for producing a water-retentive base material from them.

[Means for solving the problems] The present invention, which has been made to solve the above problems, is a water retention system characterized by crushing used diapers containing a polymeric water retention material. The gist of this paper is a method for producing a flexible base material.

Diapers containing a polymeric water-retaining material are so-called disposable disposable diapers that are generally commercially available for infants and the elderly. The polymer water retaining materials used for this are:
Examples include starch-based, cellulose-based, polyacrylic acid-based, poval-based, polyoxyethylene-based, etc.
It doesn't matter which system. Note that disposable diapers sorted from municipal garbage or separately collected include diapers containing polymeric water-retaining materials as well as diapers using cotton, pulp, etc. as water-absorbing materials; however, in the implementation of the present invention, does not require strict separation of these items. In other words, the effects of the present invention can be achieved as long as even a part of them contains a polymeric water-retaining material.

In addition, by crushing a used diaper until the size is equal to or smaller than the size of the polymeric water-retaining material contained in the used diaper, the water-retaining property of the produced water-retaining base material becomes better. Furthermore, it is also included in one embodiment of the present invention to pre-process used diapers with a detergent in order to improve the water retention of the manufactured water-retention base material, remove odor, or for hygiene purposes. .

[Function] In the dry state before use, disposable diapers contain 3 to 20% by weight of polymeric water-retaining material, polypropylene, polyester,
It contains 5 to 40% by weight of a nonwoven fabric made of viscose, rayon, polyethylene, etc., and 10 to 80% of a natural material such as a valve. Among these, polymer water-retaining materials can absorb water hundreds to thousands of times their own weight, but in the case of urine and other filth, their absorption capacity is 50 to 50 times their own weight.
It decreases to about 60 times. Therefore, used diapers are thrown away with their potential water absorbing capacity still intact.

Such used disposable diapers are usually gathered into a certain amount and crushed.

As mentioned above, disposable diapers contain a polymeric water-retaining material, so when the diaper is crushed, this polymeric water-retaining material is also destroyed and a new surface appears. As a result, the crushed polymeric water-retaining material regains its water-absorbing ability, making it possible to produce a water-retaining base material from used diapers. Therefore, by making the crushing size of the disposable diaper smaller than the size of the polymeric water-retaining material contained therein, the appearance of a new surface of the polymeric water-retaining material is ensured, and the effects of the present invention are excellent. becomes.

As mentioned above, washing may be performed before crushing to remove some solid dirt. t destination to use in this case? I
In addition to water, organic solvents such as alcohols such as methanol and ethanol, and ketones such as acetone can be used. When using water as a cleaning solution, it is undesirable to immerse the diaper in water for a long time because the polymeric water-retaining material absorbs water, and it is preferable to do it quickly by spraying water onto the surface of the used diaper. . In addition, after washing, it may be dried with hot air if necessary.

Effects of the Invention The method for producing a water-retentive base material according to the present invention provides, for example, the following:
Since used diapers are effectively reprocessed, this will help solve the urban garbage problem caused by used diapers. At the same time, it can be said to be a useful invention from the perspective of effective use of resources.

Furthermore, since the water-retaining base material produced by the method of the present invention contains a polymeric water-retaining material that has newly recovered its water-absorbing properties, it can be used as a water-absorbing and water-retaining material. In other words, in used diapers, only a small amount of the water absorption capacity of the polymeric water-retaining material is utilized due to urine and other filth, but in the water-retaining base material produced by the method of the present invention, the polymeric water-retaining material is It has excellent water absorption as it recovers its water absorption ability to a level close to its performance.

The water-retentive substrate produced according to the present invention can be used, for example, in the following ways.

Currently, with the increase in the number of livestock, processing of large amounts of cow dung has become a problem. Cow dung contains a large amount of water, making subsequent processing difficult. When such cow dung is brought into contact with the water-retentive substrate produced according to the present invention, the moisture content of the cow dung is reduced, making it easier to handle afterwards. Also,
If cow dung is mixed with a water-retaining base material instead of simply being brought into contact with it, the water absorption rate will be increased, allowing rapid mass processing.

In this case, after a predetermined period of time has elapsed, an air stream is sprayed onto the mixture, causing it to scatter, thereby separating the dried cow dung from the water-retaining base material due to the difference in specific gravity.

Cow dung dried by this method can be easily incinerated and can also be used as fuel. In addition, water-retaining substrates that have absorbed water from cow dung may be treated with bacteria to render them harmless and then disposed of. It also absorbs organic nutrients from cow dung, so it can be used as agricultural fertilizer. In this case, since the water-retaining power of the water-retaining base material is large, the water containing nutrients is not released immediately but is released little by little, so it can be used as a slow-release fertilizer.
It is a fertilizer that can be used for a long period of time and is easy to handle.

The water-retaining substrate produced according to the present invention can also be used to treat bed feces, similar to the above-mentioned cow feces treatment.

For example, if a disposable mat for raising a bed containing a water-retaining base material is manufactured and the mat is wrapped and thrown away after use, it will be easier to dispose of feces at home. Instead of a mat-like material, the water-retentive base material can be used as it is, or it can be granulated to a certain size and placed in a pet house like gravel, making it feel nice under the pet's feet.

In this case, valves and plastic components other than the polymeric water-retaining material contained in the used diaper may serve as aggregates during granulation.

Furthermore, other uses include sludge slag, which is industrial waste,
There is a dehydration process for wet-processed dust.

Even if water is removed from these using a filter or a centrifugal separator, the water content will only be reduced to about 50 to 80% at most. By bringing the water-retentive substrate produced by the method of the present invention into contact with such sludge, the water content can be further reduced by about 10 to 20%. In this case as well, the water absorption rate can be increased by mixing the water-retaining base material with sludge or the like.

[Example] Examples of the present invention will be described below. The weight composition of each component of the disposable diaper before use is: 12% polyethylene nonwoven fabric on the skin, 11% vinyl waterproof sheet on the outside, and cellulose-based polymer water retention material placed inside. 10%, 53% cotton-like natural bulb that wraps this polymeric water-retaining material, 13% absorbent paper as a layer between the pulp and nonwoven fabric, and 1% tape to adhere to the human body. Here, the polymeric water retaining material is in the form of a sheet.

After this diaper was used for an infant, solid waste was removed using high-pressure water, and the diaper was cut into pieces approximately 2 to 3 mm in size using a crusher to produce a water-retentive base material.

The water-retentive base material produced in this way has a moisture content of 70%.
The mixture was mixed with industrial sludge containing slag and allowed to stand for about 1 hour, after which the mixture was blown away with compressed air. As a result, the water-retaining base material that absorbed moisture was separated from the water-retaining base material closer to the air source, and the dried sludge was separated from the water source, and the water content of the dried sludge was reduced to 55%.

Claims (1)

[Claims] 1. A method for producing a water-retaining base material, which comprises crushing a used diaper containing a polymeric water-retaining material. 2. Production of the water-retentive base material according to claim 1, characterized in that the used diaper is crushed until the used diaper has a size equal to or smaller than the size of the polymeric water-retaining material contained in the used diaper. Method. 3. The method for producing a water-retentive base material according to claim 1 or 2, which comprises washing the used diaper in advance.