JPH08291488A - Regenerated feedstock, regenerated nonwoven fabric, regenerated interlaced nonwoven fabric, and their production - Google Patents

Abstract

PURPOSE: To obtain a regenerated feedstock, and regenerated nonwoven fabric and regenerated interlaced nonwoven fabric each containing the feedstock by disaggregating interlaced webs through mechanical shear force, thereby trying to reduce garbage by reusing interlaced webs having been considered to be hard to recycle. CONSTITUTION: This regenerated feedstock is obtained by disaggregating interlaced webs where short fibers <=2000 in aspect ratio interlaced with one another. The 2nd and 3rd other objective regenerated nonwoven fabric and regenerated interlaced nonwoven fabric contain this regenerated feedstock, respectively. Specifically, the above regenerated webs are disaggregated in water by mechanical shear force to produce the regenerated feedstock in the form of a short fiber suspension; this suspension is, in turn, webbed by wet papermaking process to produce the regenerated nonwoven fabric; and, the above suspension is webbed by wet papermaking process and the resultant web is put on a porous substrate, and a relatively moving water jet is then applied on the web to effect interlacing the fibers, thus producing the regenerated interlaced nonwoven fabric.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recycled raw material obtained by defibrating an entangled web made of short fibers, a recycled nonwoven fabric and a recycled entangled nonwoven fabric made from the recycled raw material, and a method for producing them. More specifically, the present invention relates to a recycled raw material that does not deteriorate in physical properties as a raw material for the nonwoven fabric, a recycled nonwoven fabric containing the recycled raw material, and a recycled entangled nonwoven fabric.

[0002]

2. Description of the Related Art In recent years, non-woven fabrics have been widely used in many fields in place of woven fabrics. Because of its low cost and high productivity, it can be used as a substitute for conventional woven fabrics, or can be used as a functional non-woven fabric because it can impart performance not obtained with woven fabrics. Furthermore, conventionally, the functionality of non-woven fabrics has also been utilized in the field of paper pulp as a raw material, and supply as a high-performance material has become popular.

Among them, in particular, by using a method in which a high-pressure water stream is jetted onto a web and the fibers forming the web are three-dimensionally entangled, the obtained non-woven fabric has a texture close to that of the cloth,
It is attracting attention because of its excellent touch and drape. This method is called by the name such as the hydroentanglement method.

In recent years, the problem of reducing the amount of waste has been highlighted, and there is an interest in the reuse of paper typified by newspapers and milk cartons, and plastic typified by PET bottles. The former is being used as a waste paper material, and the latter is being used as a recycled pet.

On the other hand, hydroentangled non-woven fabrics are often used for disposable purposes such as sanitary materials and medical products, and are not so much paid attention to reuse as papers and PET bottles.

In the hydroentanglement method, fibers are moved by water flow and bent, so that the fibers are entangled with each other to develop strength, and therefore, a web made of cut short fibers is suitable. Webs obtained by the dry method and the wet papermaking method correspond to this.

Most of the hydroentangled nonwoven fabrics obtained from the dry web have a fiber length of more than 20 mm, and once entangled, it is difficult to defibrate. In order to defibrate these, it is necessary to apply a strong physical shearing force,
In this case, the fibers are damaged, cut, or become entangled, so that even if they are defibrated, they are forced to be used for another purpose.

On the other hand, the hydroentangled non-woven fabric obtained from the wet web has a relatively short fiber length and is difficult to obtain strength. Therefore, it was developed by laminating a special material such as pulp on the dry web and compounding it with a cloth. It has been advanced. Recently, as described in JP-A-2-6651 and JP-A-6-65848, by using short fibers having a specific fiber length or aspect ratio, even a wet web alone can achieve high Stronger products are becoming available. However, at present, no consideration is given to the regeneration of the hydroentangled nonwoven fabric.

[0009]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and aims to effectively reuse the entangled web.

[0010]

Means for Solving the Problems The present inventors have diligently studied the above problems. As a result, an entangled web in which short fibers having a specific aspect ratio are entangled, can be regenerated as a raw material for a nonwoven fabric by using a physical shearing force, and can be regenerated as a raw material for a non-woven fabric. It has been found that non-woven fabrics and regenerated entangled non-woven fabrics are obtained. The present invention has been achieved based on these findings.

That is, the present invention has the following configuration. (1) A recycled material obtained by defibrating an entangled web in which short fibers having an aspect ratio of 2000 or less are entangled. (2) A recycled non-woven fabric containing the recycled raw material. (3) A regenerated entangled nonwoven fabric containing the regenerated raw material. (4) A method for producing a recycled raw material, which comprises defibrating an entangled web in which short fibers having an aspect ratio of 2000 or less are entangled with each other in water by a physical shearing force to obtain a suspension of short fibers. (5) A method for producing a regenerated nonwoven fabric, which comprises forming a web containing the suspension containing the regenerated raw material by a wet papermaking method. (6) Regeneration characterized in that a suspension containing the above-mentioned regenerated raw material is formed into a web by a wet papermaking method, loaded on a porous support, and a relatively moving water stream is jetted to entangle the fibers. Method for producing entangled nonwoven fabric.

The present invention will be described in detail below. First,
Aspect ratio 2 required to obtain the recycled material of the present invention
An entangled web in which 000 or less short fibers are entangled will be described. The aspect ratio refers to the ratio (L / D) between the fiber diameter (D) and the fiber length (L). More preferably, the aspect ratio is 2000 or less and the fiber length is 20 mm or less. An entangled web having an aspect ratio of more than 2000 is not preferable if it is strongly entangled, because it is difficult to defibrate and a uniform recycled material cannot be obtained. Even if the entanglement is gentle, the fibers are entangled during the defibration, which is not preferable.

The entangled web used in the present invention is an entangled short fiber having the above aspect ratio, and the manufacturing method thereof is not particularly limited. For example, a broke of a hydroentangled nonwoven fabric, a slitted portion, a sample after measurement of physical properties, and the like can be used. Further, the entangled nonwoven fabric obtained by the needle punching method can also be used as the entangled web used in the present invention.

However, the one in which the fibers are firmly bonded by the non-water-soluble resin and the one in which the fibers are firmly bonded by the non-water-soluble component constituting the fibers are difficult to defibrate and are uniform. It is not preferable because no regenerated raw material can be obtained. There is no particular problem in the case of a loosely bonded one or a water-soluble resin bonded one.

The dry basis weight of the entangled web is 150 g / m ² or less, more preferably 100 g / m ² or less. 150 g /
A basis weight larger than m ² is not preferable because it is difficult to defibrate and a uniform recycled material cannot be obtained.

Organic fibers, semi-synthetic fibers, recycled fibers and natural fibers are preferable as the types of fibers constituting the entangled web used in the present invention. Metal fiber, ceramic fiber,
Inorganic fibers and the like are not preferable because the fibers are damaged or broken when a shearing force is applied.

The organic synthetic fibers include polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyolefins such as polypropylene, polyethylene and polystyrene, nylons such as nylon 6, nylon 66 and nylon 12, polyacrylonitrile, polyvinyl alcohol and polyvinylidene chloride. , Polyvinyl chloride, urethane and the like, as well as fibers containing resin such as aromatic polyamide, polyphenylene sulfide, polyimide, polybenzimidazole and polyparaphenylene benzobisoxazole. These resins are available in the form of homopolymers, copolymers, blends, copolymers and the like. Further, the fiber may be in the form of a so-called composite fiber having a core-sheath structure, a side-by-side structure, a separated and separated structure, and a sea-island structure, which are obtained by combining a plurality of resins.

The semi-synthetic fibers are fibers such as triacetate and diacetate. Regenerated fiber refers to a fiber obtained by spinning a solution of regenerated cellulose such as viscose rayon, polynosic rayon, or lyocell, collagen, alginic acid, and chitin. Natural fibers are hemp, cotton, ramie, isolated from herbs and woody plants.
It refers to cellulosic fibers such as wood pulp, kenaf, kozo, mitsumata and bagasse, and protein fibers such as wool and silk.

Further, these fibers are dyed, metal is vapor-deposited or sprayed on the surface, water absorption, hygroscopicity, conductivity, flame retardancy, deodorization, antibacterial property, ultraviolet shielding property, heat retention property,
It may have functions such as antiallergic property and ion exchange property.

The cross-sectional shape of the fibers used here is not only circular or elliptical but also flat, triangular, Y-shaped, T-shaped, U-shaped,
It may have a so-called atypical cross-sectional shape such as a star shape or a dog bone shape. Further, it may be hollow. It is also possible to use an entangled web in which fibers other than the above are mixed in a small amount, but it goes without saying that the entangled web should not be in a range that hinders the present invention.

The regenerated raw material of the present invention can be manufactured by the following method. A suspension of short fibers can be obtained by a method of defibrating an entangled web in which short fibers having an aspect of 2000 or less are entangled in water under physical shearing force, and can be used as a recycled material. The physical shear force is Pulper,
Those obtained by vigorous stirring with a mixer, homogenizer, etc. are preferred. With gentle agitation using an agitator or a washing machine, the strongly entangled entangled web does not change at all, and even the weakly entangled web does not defibrate uniformly.

The concentration during strong stirring is not particularly limited, and is 0.1
The defibration can be performed in the range of about 3%. Further, it is also a preferable method to promote the defibration by preliminarily adding a surfactant such as a fiber softener to water to improve the slippage between the short fibers.

Next, the recycled nonwoven fabric of the present invention will be described. A recycled nonwoven fabric can be obtained using the above-mentioned recycled raw materials. There is no particular limitation on the proportion of the recycled raw material in the recycled nonwoven fabric, and the recycled raw material may be used in any amount depending on the application and purpose. There are no particular restrictions on the materials to be mixed in addition to the recycled materials, and fiber materials, powders and the like can be appropriately selected and used.

The method for producing the recycled nonwoven fabric of the present invention includes:
Considering the fact that the aspect ratio is small, the fiber length is short, and the state of a suspension of short fibers, a method of forming a web by a wet papermaking method that can be used in a suspension state at the time of adjustment is preferable.

After forming the web, an adhesive is applied and dried to obtain a recycled nonwoven fabric. A nonwoven fabric can also be obtained by treating at a temperature above the melting point of the material forming the web.

Next, the regenerated entangled nonwoven fabric of the present invention will be described. It contains the above-mentioned recycled material and is entangled with short fibers. Similar to the recycled nonwoven fabric, there is no particular limitation on the proportion of recycled raw material in the recycled entangled nonwoven fabric, and the recycled raw material may be used in any amount depending on the application and purpose. As the material to be mixed in addition to the regenerated raw material, it is preferable to use short fibers whose strength is developed by entanglement, or those which do not fall off from the web even by the entanglement treatment.

The regenerated entangled non-woven fabric of the present invention can be formed into a web by a wet papermaking method, like the regenerated non-woven fabric.
A method in which the web is loaded on a porous support and a relatively moving water stream is jetted to entangle the fibers.

The porous support used is a plain weave, a twill weave, or the like, and is obtained by punching a wire made of a metal such as stainless steel or bronze, or a plastic such as reinforced polyester or polyamide, or a metal plate. The obtained porous plate or the like is preferable.

As a method of relatively moving the web and the water flow, a method of rotating a conveyor type or drum type support is convenient.

It is preferable to use a water stream having a diameter of 150 μm or less and a columnar water stream. The columnar water stream is jetted from a nozzle hole having a small diameter. The diameter of the water flow is 150μ
If it is larger than m, a large amount of energy flow hits the web at one time, the web is damaged, the traces of water flow are conspicuous, and the surface quality is deteriorated, which is not preferable.

The interval between water streams (nozzle hole spacing)
Is preferably 1.5 mm or less. If the interval is wider than 1.5 mm, not only the efficiency of entanglement is poor, but also the traces of the water stream are not noticeable, which is not preferable. There is no particular limit to the pressure, but 3
It is suitable to use in the range of 0 to 250 kg / m ² .

In addition to the above, regarding the entanglement device, it is important to select the number of nozzle heads and the number of entanglements within a range where sufficient entanglement can be obtained in consideration of the type of web, basis weight, processing speed, and water pressure. Further, as a method of further improving the surface quality, the nozzle diameter and the nozzle interval are individually decreased or both of them are sequentially decreased, the nozzle head is rotationally moved, and the web support is vibrated left and right. There are things to do. Further, after the entanglement, a wire mesh of 40 to 100 mesh is inserted between the nozzle and the web, and the columnar water stream is sprinkled to spray the web, so that the surface quality can be improved. It is also possible to stack and entangle other webs in the entanglement process.

The web which has been subjected to the entanglement treatment in this way has excess water removed by suction or a wet press during or after the entanglement, and then the air dryer, the air-through dryer, the cylinder dryer or the suction drum. Using a dryer,
Drying can be performed.

The recycled nonwoven fabric and recycled entangled nonwoven fabric of the present invention are provided with softening agents, antistatic agents, water repellents, water absorbing agents, SR agents and the like, hot pressing, embossing, rubbing, creping, bending and the like. Post-processing can be performed, and new performance can be imparted. Further, there is no limitation in using it by combining it with another sheet material.

[0035]

The present invention relates to a recycled raw material obtained by defibrating an entangled web having a specific aspect ratio by mechanical shearing force, and a recycled nonwoven fabric containing the recycled raw material.
Regenerated entangled nonwoven fabric. Moreover, it is a manufacturing method thereof. The regenerated raw material of the present invention can be obtained without damaging short fibers, and effectively acts as a raw material for a regenerated nonwoven fabric or a regenerated entangled nonwoven fabric.

By utilizing the present invention, the entangled web, which has hitherto been difficult to recycle, can be recycled as a raw material for a nonwoven fabric, and it is expected to beautify the environment and reduce the amount of dust.

[0037]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
All percentages stated for fibers in the examples are by weight.

Next, the method for evaluating physical properties of the present invention will be described. <Evaluation items> 1. Dispersion state of recycled material It was judged visually. 2. Strength of recycled nonwoven fabric and recycled entangled nonwoven fabric (kg / 20mm) Width 20mm, length 150mm sample, span 100m
Tensilon HTM- is the maximum load value until the sample breaks when the sample is pulled at a speed of 200 cm / min. It measured using 100 (made by Orientech company). 3. Appearance of recycled nonwoven fabric The appearance of the recycled nonwoven fabric was visually evaluated.

Reference Example 1 Fineness 0.1 denier (fiber diameter 3.5 μm), fiber length 6 m
m (aspect ratio: 1700) polyacrylonitrile fiber (acrylic fiber: manufactured by Mitsubishi Rayon Co., Bonnell) was put into water together with a nonionic surfactant, and stirred strongly with a pulper until the fiber bundle disappeared. A suspension of

Reference Example 2 Water was added to the suspension of Reference Example 1 to dilute it, and then high molecular weight polyacrylamide (0.1%) was added while gently stirring with an agitator.
A 1% solution (viscous agent) was added and thickened, and stirring was continued to obtain a uniformly dispersed fiber suspension (slurry). Using this slurry, a slanted short-net paper machine was used to make a paper having a dry weight of 80 g / m ² to obtain a web. Then
It is loaded on a stainless steel 100 mesh equivalent plain weave wire-like porous support, a water flow is jetted from a head equipped with nozzles shown in Table 1 below, and a web transfer speed 1
The front and back of the web were entangled once each at 5 m / min and dried at 110 ° C. using a suction drum dryer to obtain a hydroentangled nonwoven fabric.

[0041]

[Table 1]

Reference Example 3 80% by weight of the acrylic fiber of Reference Example 1 and 20 polyester-based binder fibers (Melty 4080 manufactured by Unitika Ltd.)
A web was formed by the same method as in Reference Example 1 except that the weight% was used, and the nonwoven fabric was obtained by drying at 110 ° C. without jetting a water stream.

Example 1 A high-speed mixer (commercial blender, manufactured by Warin Co.) was charged with the hydroentangled nonwoven fabric of Reference Example 2 as an entangled web so as to have a concentration of 1% and stirred for 60 seconds to suspend short fibers. A recycled raw material was obtained as a liquid. The state of dispersion of the short fibers visually confirmed was uniform and good.

Example 2 A regenerated entangled nonwoven fabric was obtained in the same manner as in Reference Example 2 except that the regenerated raw material of Example 1 was used.

Example 3 The recycled entangled nonwoven fabric of Example 2 was used as the entangled web in Example 1.
The same method was used to defibrate it to obtain a recycled raw material, which was used to obtain a recycled entangled nonwoven fabric by the same method as in Reference Example 2.

Example 4 80% by weight of the recycled raw material of Example 1 in dry weight was added to polyester binder fiber (Melty 4 manufactured by Unitika Ltd.).
080) 20% by weight was used to obtain a regenerated nonwoven fabric by the same method as in Reference Example 3.

Reference Example 4 A suspension of short fibers was obtained in the same manner as in Reference Example 1, except that the same acrylic fiber as in Reference Example 1 with a fiber length of 8 mm (aspect ratio 2300) was used.

Reference Example 5 Using the suspension of Reference Example 4, a hydroentangled nonwoven fabric was obtained in the same manner as in Reference Example 2.

Comparative Example 1 The hydroentangled nonwoven fabric of Reference Example 5 was used as the entangled web in Example 1
The same method was used to defibrate and obtain a recycled material. Since an undisentangled fragment was found in the recycled material, it was disentangled for another 30 seconds. Tangles of short fibers were found in the obtained recycled raw material.

Comparative Example 2 A regenerated entangled nonwoven fabric was obtained in the same manner as in Example 2 except that the regenerated raw material of Comparative Example 1 was used. Tangles were found in the obtained fibers.

Reference Example 5 The hydroentangled nonwoven fabric of Example 2 was treated 5 times in a fully automatic washing machine. No noticeable change was observed in the appearance of the nonwoven fabric. It was confirmed that the short fibers were not disentangled by gentle stirring.

The results of Reference Examples 1 to 4, Examples 1 to 4 and Comparative Examples 1 and 2 are summarized in Tables 2 and 3. Table 2
Is an evaluation of the dispersion state of the regenerated weight loss.

[0053]

[Table 2]

[0054]

[Table 3]

[0055]

From the above results, it has been found that a regenerated raw material that can be used as a raw material for a nonwoven fabric can be obtained by defibrating an entangled web having a specific aspect ratio by mechanical shearing force. It was also found that the regenerated nonwoven fabric and regenerated entangled non-woven fabric obtained by using the regenerated raw material were comparable in strength and appearance to those obtained without using the regenerated raw material. By the method of the present invention, it is expected that the entangled web, which has been conventionally regarded as a waste, can be reused, and that it is effective in reducing the amount of dust.

Claims (6)

[Claims] 1. A recycled material obtained by defibrating an entangled web in which short fibers having an aspect ratio of 2000 or less are entangled. 2. A recycled non-woven fabric containing the recycled raw material according to claim 1. 3. A recycled entangled nonwoven fabric containing the recycled raw material according to claim 1. 4. A method for producing a recycled raw material, which comprises defibrating an entangled web in which short fibers having an aspect ratio of 2000 or less are entangled with each other in water by a physical shearing force to obtain a suspension of short fibers. . 5. A method for producing a recycled non-woven fabric, which comprises forming a suspension containing the recycled raw material according to claim 4 into a web by a wet papermaking method. 6. A method of forming a suspension containing the regenerated raw material according to claim 4 into a web by a wet papermaking method, loading the web on a porous support, and injecting a relatively moving water stream to entangle the fibers. A method for producing a regenerated entangled nonwoven fabric, which comprises: