JPH03860A - Conjugate non-woven fabric and production thereof - Google Patents

Abstract

PURPOSE:To obtain the subject non-woven fabric excellent in balance of strength and softness and in water absorption properties by piling up a sheet-shaped material composed of short fibers on a sheet-shaped material composed of filaments consisting of a sheath-core type conjugate fiber and carrying out water jet entangling treatment in plural times. CONSTITUTION:On one or more sides of a sheet-shaped material composed of filaments consisting of a sheath-core type conjugate fiber in which a polymer having a lower melting point than that of the core component is used as the sheath component, a sheet-shaped material composed of short fiber web or pulp of a natural fiber is piled up. The resultant laminated material is placed on a porous supporting member and led to collide with a fluid jet having <30kg/cm<2> pressure to preliminarily entangle both the sheet-shaped materials. The obtained preliminarily entangled material is then led to collide with a jet of >=50kg/cm<2> to mutually entangle both the sheets without cutting the fibers constituting the above mentioned laminated sheets, thus obtaining the objective conjugate non-woven fabric having >=11kg tensile strength, <=65g softness and <=5sec. water absorption properties. The above mentioned non-woven fabric can be widely utilized in fields such as a wiping cloth, a dehydrating roller material and a material for clothes.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is... The present invention relates to a composite nonwoven fabric consisting of a core-sheath type composite filament and a short fiber sheet of natural fibers (hereinafter sometimes simply referred to as a short fiber sheet), and a method for producing the same. A multifunctional composite material that combines the strength of sheath-type composite filaments with the water absorbency and soft texture of natural fibers or pulp, and can be used in both clothing and industrial materials fields. The present invention relates to a nonwoven fabric and a method for producing the same.

(Prior Art) Conventionally, a nonwoven fabric made of continuous filaments of synthetic fibers exhibits strength as a fabric by bonding the constituent fibers together using an adhesive or self-adhesive property of the filaments.

Since these nonwoven fabrics are composed of filaments, their tenacity has reached a sufficiently satisfactory level, but since the filaments are joined using adhesives or heat-sealed fibers, their flexibility is limited. There are many things that are scarce.

In order to solve this drawback, a technique has long been known to form a sheet by intertwining fibers with each other, rather than by bonding filaments together, as a joining method between single fibers. That is, there is a needle punch method in which a sheet-like material made of continuous filaments of synthetic fibers is subjected to needle punch treatment to mechanically entangle the constituent fibers with each other. However, the nonwoven fabric produced by this needle punching method has the disadvantage that the fibers are cut during punching, so that the properties of continuous filaments are lost and the tenacity becomes low.

Furthermore, a method for producing a nonwoven fabric using a hydroentanglement method has been proposed to overcome the drawbacks of the needle punch method.

Regarding the non-woven fabric made of continuous filaments of synthetic fibers produced by this method, it has already been published in Japanese Patent Publication No. 54-11429.
Disclosed in the issue. However, since the nonwoven fabric produced by this method was composed of only 9 synthetic fiber continuous filaments, the entanglement of the constituent filaments was weak.

Furthermore, it is already known that a laminate consisting of a long fiber sheet and a short fiber sheet made of a single polymer can be obtained by a hydroentanglement method for the purpose of imparting multifunctionality to a nonwoven fabric. The method of intertwining each other was developed in Japanese Patent Application Laid-open No. 1983
-211354. However, although the composite nonwoven fabric produced by this method has an excellent texture, when laminated to the extent that the appearance quality of the short fiber sheet is not impaired, the entanglement between the fibers between the eyebrows is insufficient. Therefore, the strength of the nonwoven fabric was low.

(Problems to be Solved by the Invention) In view of the above-mentioned problems, an object of the present invention is to provide a multifunctional nonwoven fabric having excellent strength and flexibility as well as water absorbency, and a method for producing the same. It's about doing.

More specifically, a composite nonwoven fabric is formed by using a hydroentangling method to form a laminate of a synthetic fiber continuous filament sheet having a core-sheath structure and a short fiber sheet by a hydroentangling method, with filaments intertwined between the laminates. The object of the present invention is to easily provide a comprehensively excellent composite nonwoven fabric that takes advantage of the advantages of core-sheath type composite fibers and also has water absorbency, which is a characteristic of natural fibers or pulp.

(Means for Solving the Problems) In other words, the present invention provides a composite nonwoven sheet-like product in which a short fiber web of natural fibers or pulp is laminated on at least one side of a long-fiber sheet-like product made of core-sheath type composite filaments. In the long fiber sheet-like material, the core-sheath type composite filaments constituting the sheet-like material intersect with each other in random directions and are entangled without cutting each other,
On the other hand, the short fiber sheet consisting of a short fiber web of natural fibers or pulp constituting the other part of the composite nonwoven sheet is one in which the fibers are entangled with each other, and A long fiber sheet material and a short fiber sheet material entangled with the composite filament are characterized by having a tensile strength of 11 kg or more, a flexibility of 65 g or less, and a water absorption property of 5 seconds or less. The gist of this paper is a composite nonwoven fabric and its manufacturing method.

What is the synthetic fiber used in the composite nonwoven fabric of the present invention?

Polyester polymers consisting of copolyesters such as polyethylene terephthalate and polyethylene isophthalate/terephthalate, nylon 6° nylon 66,
Nylon 610. Nylon8. Two types of polymers were selected from polyamide-based polymers made of nylon 12°, nylon 46, etc., and copolymers thereof, polyolefin-based polymers made of polypropylene, polyethylene, polybutylene, etc., and copolymers thereof, and the polymer with a low melting point was selected. It is a core-sheath type composite fiber whose core component is a sheath component and a polymer with a high melting point. Note that it is preferable that the difference in melting point between the two is at least 30°C.

The above-mentioned core-sheath type composite fiber can be obtained by using a conventionally known core-sheath type composite nozzle, melting two types of polymers, merging them into a core-sheath shape with a spinneret, and spinning them from the nozzle. The method of producing a long fiber sheet using this core-sheath type composite fiber by the spunbond method is to take the spun yarn of the core-sheath type composite fiber using an air sucker, and then use a high voltage generator. After opening the fibers using a fiber opening device such as the following, the filaments are collected on a moving filament collection support to create a web, and the web is temporarily pressed using a roller or the like. The long fiber sheet material used in the present invention can be obtained.

The single fiber fineness of the synthetic fibers constituting the long fiber sheet is preferably 0.3 denier or more and 5 denier or less from the viewpoint of the appearance and flexibility of the surface of the nonwoven fabric. The object is a laminated nonwoven fabric in which a natural fiber web or pulp is superimposed on one or both sides of the long fiber sheet, and multifunctionality is achieved through compositing. The natural fibers or pulp used in the present invention include cotton, wool, hemp,
Various pulps such as softwood pulp, hardwood pulp, and hemp pulp can be used. The natural fiber web used is a web obtained by carding raw cotton using a carding machine. As for the arrangement of the fibers constituting the web, a parallel web arranged in the advancing direction of the card machine, a random web arranged randomly, or a semi-random web arranged halfway between the two can be used.

Next, one example of a specific method for manufacturing the composite nonwoven fabric of the present invention will be shown below, but the present invention is not limited thereto. However, according to the method of the present invention, the desired composite nonwoven fabric can be obtained easily and efficiently.

Lamination of a long fiber sheet and a natural fiber web or pulp is carried out by superimposing the two and then entangling the fibers with each other using a hydroentanglement method.

More specifically, a preferable entangled nonwoven fabric can be obtained by dividing the liquid jet several times and colliding it with the laminate, and the long seaweed fiber sheet and the natural fiber web can be obtained without cutting the constituent fibers. Alternatively, pulp is entangled with each other by long fiber filaments.

To describe a specific method for laminating the above-mentioned laminate, 9 The fluid jet used in the present invention has orifices with a hole diameter of 0.05 to 1□Qmm arranged in one or more rows with an inter-orifice distance of 0.5 to 10 mm. It consists of a columnar flow ejected from a large number of orifices. The columnar flow is sent from the orifice to 30
It is ejected at a pressure of less than kg/cd and impinges on the laminate. Subsequently, a columnar flow is ejected from the orifice at a pressure of 50 kg/ci or more to entangle the constituent fibers of the laminate without cutting them.

At this time, it is preferable that the orifice head be reciprocated in the cross-sectional direction of the stacked body with an amplitude equal to the distance between the orifices to cause the columnar flow to collide uniformly.

Note that the fluid jet used in the present invention uses water in the shell. Hot water may be used, or water mixed with additives may be used.

The purpose of the first water channel combining treatment performed under the condition of a pressure of 30 kg/crl and no droplet is to preliminarily entangle the long fiber sheet material and the short fiber sheet material. In the case of this first water flow path combining process, if the pressure exceeds 30 kg/cnf, the constituent fibers of the short fiber sheet are not sufficiently entangled with each other, and the constituent fibers are disturbed by the water flow, resulting in the web having a fabric weight. This is undesirable as it will cause spots.

Next, in the second water channel joining process performed under the conditions of pressure 50 kg / cnf JJ, the first water channel It is preferable to use a columnar flow ejected from an orifice having a hole diameter larger than the orifice hole diameter used in the combining process. In addition, if stronger entanglement is required, the second water flow path joining process may be repeated a plurality of times or more under the same conditions.

The porous support member on which the above-mentioned laminate is placed may be any material that can remove the fluid jet that has passed through the laminate without resistance, and may be a porous member of 90 mesh or more, such as wire mesh, 9 synthetic fibers, etc. is desirable.

Further, after drying and removing the water used in the hydroentanglement treatment remaining in the composite nonwoven fabric, it is also possible to perform a dry heat treatment using a thermal calendar or a hot embossing roll. This dry heat treatment can improve the strength of the nonwoven fabric, and obtaining a nonwoven fabric with good texture and high strength can only be achieved by using the core-sheath composite fiber of the present invention. That is, since the dry heat treatment described above can be performed at a low temperature, the strength is improved without the constituent fibers being thermally hardened.

As detailed above, the composite nonwoven fabric of the present invention is produced by entangling the constituent fibers by hydroentangling a conventional laminate of a sheet of continuous filaments of synthetic fibers made of a single polymer and a sheet of short fibers. Unlike traditional non-woven fabrics, this non-woven fabric has a good balance of strength and flexibility, and also has excellent water absorption.

In some cases, composite nonwoven fabrics with good productivity can be obtained.

Here, the composite nonwoven fabric with a good balance of both strength and flexibility, which is the object of the invention 9, has the tensile strength shown below, specifically, the vertical strength and the horizontal strength (strength calculated per area weight of 100 g/m'). This applies to products with a total strength of 11 kg or more and a flexibility of 65 g or less. (See Figure 1) Furthermore, the above-mentioned dry heat treatment also improves the strength of the nonwoven fabric and melts the low melting point components.

A new surface pattern is formed, and the appearance of the nonwoven fabric can also be improved.

(Function) The composite nonwoven fabric of the present invention is composed of a long fiber sheet of a core-sheath type composite filament using a polymer having a lower melting point than that of the core component as a sheath component. compared to similar items.

It has the advantage that dry heat treatment can be performed at low temperatures. That is,
Since the dry heat treatment can be performed at a low temperature, the constituent fibers are less hardened by heat, which also leads to improved flexibility of the nonwoven fabric. In addition, the filaments are entangled in the short fiber sheets that make up the laminate, and there is little disturbance of the short fiber sheets, so the nonwoven fabric has a good appearance, high tenacity, and wind resistance. We believe that the situation will also be softer.

(Example) The present invention will be specifically explained below using examples.

The tensile strength, flexibility, and water absorption of the nonwoven fabric used in the following measurements are determined by the following methods.

(1) Tensile strength 3cm width) Convert the measured value by the IJ Tsubu method (using a constant speed tensile tester with a tensile speed of 20cm/min) to a unit weight of 100g/m', and calculate the total value of vertical strength and horizontal strength. Displayed in kg.

(2) Flexibility Measured values of a 15 cm x 15 cm nonwoven fabric with a slit width of 10 cm using a handle-o-meter type tester were expressed in duram units.

(3) Attach a 20cm x 20cm water-absorbent nonwoven fabric to a metal ring (15cm diameter), adjust the tip of the billet to a height of 1 am from the surface of the nonwoven fabric, and then
When a cc water droplet was dropped, the time from when the water droplet reached the surface of the nonwoven fabric until it permeated was measured. Note that the measurements were performed with the natural fiber side facing up.

Example 1 A core-sheath composite filament with a core-sheath composite ratio of 1:1, in which the core component polymer is polypropylene and the sheath component polymer is polyethylene, was melt-spun to a single fiber fineness of 3 denier, and spun using an air sucker. The fibers are taken up, opened with a high-voltage opening device, collected on a wire mesh, and then temporarily pressed together to form a randomly arranged long fiber sheet (fabric weight 75
g/m'').

On top of this long fiber sheet material, cotton (basis weight: 25 g/m'') made of carded parallel web of natural fibers was laminated, and this laminated body was transferred to a conveyor made of 90 mesh endless wire mesh at a speed of 2 m/min. , water pressure 20kg/
The first water channel merging process was carried out by colliding a fluid jet with a weak cut. The conditions for entanglement due to this fluid jet are as follows: orifice hole diameter is 0.1 mm, distance between orifices is 1 mm, orifice arrangement is arranged horizontally in one row, 9 years old, distance between the refrigeration surface and the laminate is 5 cm, the motion of the orifice head is with an amplitude of 1 m + n, and a period of IQ cps. Ta. Next, successively, water pressure 75kg
/crl, the second water channel merging process was carried out. The conditions for the orifice used in the second water flow path combining process were 0.125 pore diameter.
+nm, distance between orifices 1+nm.

Orifice arrangement: 2 rows horizontally (orifices in the 2nd row.

Exists on each line extending vertically from the midpoint between adjacent orifices in the first row, and the first and second rows are geometrically parallel), and the relationship between the orifice surface and the laminate distance 5
am, the motion of the orifice head is.

It reciprocated in the horizontal direction with an amplitude of 1 m and 19 cycles IQcps.

After carrying out the second water flow treatment, the laminate was further turned over and an entanglement treatment was performed as a third water flow path combination treatment under the same conditions as the second water flow path combination treatment. Table 1 shows the performance of the obtained composite nonwoven fabric.

(Hereafter, margin) Table 1 (Hereafter, margin) Example 2 Following the hydroentanglement treatment performed in Example 1.

Except for adding two more hydroentanglement treatments under the 2nd and 3rd hydroentanglement treatment conditions of Example 1, the other conditions were all (A composite nonwoven fabric was produced under the same conditions as Example 1. Table 1 shows the performance of the composite nonwoven fabric.

Example 3 Instead of the long fiber sheet material used in Example 1, in which core-sheath type composite filaments with a single yarn fineness of 3 denier were randomly arranged, core-sheath type composite continuous filaments with a single yarn fineness of 0.6 denier were randomly arranged. A composite nonwoven fabric was produced under all the same conditions as in Example 1 except for using the long fiber sheet-like material prepared in Example 1. Table 1 shows the performance of the obtained composite nonwoven fabric.

Example 4 The core component polymer is polyethylene terephthalate,
The sheath component is made of polyethylene, single yarn fineness is 3 denier,
The other conditions were that a long-fiber sheet material (fabric weight 75 g/g) in which core-sheath composite filaments with a core-sheath composite ratio of 1=1 were randomly arranged was used.

A composite nonwoven fabric was produced under the same conditions as in Example 1.

Table 11 shows the performance of the obtained composite nonwoven fabric.

Example 5 Instead of the core-sheath type composite filament with a single filament fineness of 3 denier used in Example 4, a long fiber sheet-like material in which core-sheath type composite filaments with a single filament fineness of 0.6 denier were randomly arranged was used. The composite nonwoven fabric was manufactured under the same conditions as in Example 1 except for the following conditions. The performance of the obtained composite nonwoven fabric is shown below.

Example 6 Instead of the natural fiber cotton used in Example 1.

A composite nonwoven fabric was produced under the same conditions as in Example 1 except that paper made of softwood pulp (fabric weight 25 g/m') was used. Table 1 shows the performance of the obtained composite nonwoven fabric.

Example 7 The composite nonwoven fabric obtained in Example 1 was embossed under the following conditions: a linear pressure of an embossing roller of 30 kg/cm, a pressure area ratio of 15%, and a heat treatment temperature of 110°C.

Table 1 shows the performance of the obtained composite nonwoven fabric after hot embossing treatment.

Comparative Example 1 A long-fiber sheet (fabric weight IQOg/go) in which continuous filaments of single polymer type synthetic fibers made of polyethylene terephthalate and having a fineness of 3 deniers were randomly arranged was prepared according to Example 1.

Next, this long fiber sheet-like material (fabric weight: 100 g/m') was subjected to hydroentanglement treatment in a single layer under the same conditions as in Example 1.

A nonwoven fabric was obtained. Table 1 shows the performance of the obtained single-layer nonwoven fabric.

Comparative Example 2 A long fiber sheet with a single optical fineness of 3 denier made of polyethylene terephthalate used in Comparative Example 1 (basis weight 75 g)
A parallel web (fabric weight 25 g/m") made of carded short fibers made of polyethylene terephthalate with a fineness of 2 denier and a fiber length of 51 mm was laminated on top of the polyethylene terephthalate, and the laminate was made exactly the same as in Example 1. Hydroentanglement treatment was performed under the following conditions. Table 1 shows the performance of the obtained composite nonwoven fabric.

Comparative Example 3 A long-fiber sheet made of the core-sheath composite filament with a single fiber fineness of 3 deniers used in Example 1 (fabric weight 75 g/m
”) instead of 100% polyethylene terephthalate
Except for using a long fiber sheet with a single yarn fineness of 3 denier (basis weight 75 g/m").

A composite nonwoven fabric was produced under the same conditions as in Example 1 except for all other conditions. Table 1 shows the performance of the obtained composite nonwoven fabric.

Comparative Example 4 A long fiber sheet made of the core-sheath type composite filament with a single fiber fineness of 3 deniers used in Example 1 (fabric weight 75 g/m
A composite nonwoven fabric was produced under the same conditions as in Example 1, except that a long fiber sheet of 3 denier single filament made of 100% polypropylene was used instead of 100% polypropylene. Table 1 shows the performance of the obtained composite nonwoven fabric.

Comparative Example 5 Instead of the core-sheath type composite filament with a single yarn fineness of 3 denier used in Example 1, a long fiber sheet-like material with a single yarn fineness of 3 denier made of 100% polyethylene (basis weight 75 g/
A composite nonwoven fabric was produced under all the same conditions as in Example 1 except that rn') was used. Table 1 shows the performance of the obtained composite nonwoven fabric.

As is clear from the above-mentioned Examples 1 to 7 and Comparative Examples 1 to 5, the present invention has a long fiber sheet material in which the single yarn is a core-sheath type composite filament, and a short fiber sheet material in which the single yarn is a core-sheath type composite filament and a short fiber sheet material consisting of a natural fiber web or pulp. The present invention relates to a composite nonwoven fabric laminated with materials and a method for manufacturing the same.

Composite nonwoven fabric made by laminating a long fiber sheet and a short fiber sheet made of single polymer filaments (Comparative Example 3)
When compared with 1 to 5), the composite nonwoven fabric of the present invention had a good balance between strength and flexibility, and also had water absorbency.

In the case of a composite nonwoven fabric (Comparative Example 2) consisting of a long-fiber sheet made of single polymer filaments and short synthetic fibers (Comparative Example 2), strength and flexibility are in the well-balanced area of the present invention. However, it did not have water absorbency and was unsuitable for use as a sanitary material such as disposable diapers, making it impossible to achieve the present invention.

(See the black circles in the shaded areas in the figure.) FIG. 1 illustrates the relationship between the strength and flexibility of the nonwoven fabrics of Examples 1 to 7 and Comparative Examples 1 to 5. The white circles in the figure indicate examples of the present invention, and the black circles indicate comparative examples.

(Effects of the Invention) The composite nonwoven fabric of the present invention has a well-balanced performance of strength and flexibility, and by combining a natural fiber web or pulp, it has a better performance than a nonwoven fabric made of only one synthetic fiber. Wiping cloth has excellent water absorption properties, and the manufacturing method for the composite nonwoven fabric is simple, making it easy to manufacture nonwoven fabrics.
It can be widely used in the fields of water-absorbing roller materials, clothing materials, etc.

(Hereafter, margin)

[Brief explanation of drawings]

Figure 1 is. Examples 1 to 7 and Comparative Examples 1 to 5 It is a graph showing the relationship between nonwoven fabric strength and flexibility.

Claims (2)

[Claims] (1) A composite nonwoven sheet consisting of a long fiber sheet consisting of a core-sheath type composite filament, on at least one side of which a short fiber web of natural fibers or pulp is laminated; The core-sheath composite filaments that make up the sheet material cross each other in random directions and are entangled without cutting each other, while the natural fibers that make up the other part of the composite nonwoven sheet material cross each other in random directions and are entangled without cutting each other. A short fiber sheet made of a short fiber web or pulp is one in which the fibers are entangled with each other, and the long fiber sheet and the short fiber sheet are further bonded to the composite filament. The tensile strength of the entangled structures is 11 kg or more.
A composite nonwoven fabric characterized by a flexibility of 65g or less and a water absorption of 5 seconds or less. (2) A laminate in which at least one side of a long fiber sheet made of a core-sheath type composite filament is overlaid with a short fiber web made of natural fibers or a short fiber sheet made of pulp is placed on a porous support member. and the pressure is 30kg/cm^
The first step is to preliminarily entangle the long fiber sheet material and the short fiber sheet material by impinging a fluid jet of less than 2 mm on the laminate, followed by applying pressure to the preliminarily entangled laminate material. 5
A composite nonwoven fabric comprising a second step of colliding jets of 0 kg/cm^2 or more to entangle the fibers of the laminated sheet without cutting the fibers. manufacturing method.