JPH0241452A - Novel nonwoven fabric and production thereof - Google Patents

Abstract

PURPOSE:To obtain a nonwoven fabric having three-dimensionally entangled fibers of a prescribed length with fibrillated tips by cutting and dispersing a multifilamentary or towy filament bundle with a roller with set needles, laminating the dispersion on a net and entangling the laminated layer with a high- pressure water columnar stream. CONSTITUTION:A multifilamentary or towy filament bundle 1 (preferably consisting of acrylic fibers) is cut and dispersed with a roller 4 set with needles rotating at >=1000m/min, preferably 1000-5000m/min surface speed, sucked by a vacuum device 9, dropped and laminated onto a net conveyor 15 and entangled with water columnar devices 10, 11 and 12 under 10-100kg/cm<2>G, preferably 30-80kg/cm<2>G water pressure and dried in a dryer 17 to afford a flexible and bulky nonwoven fabric, having 0.8-1.3 dispersion orientation index in the plane direction and three-dimensionally entangled fibers with at least one end fibrillated into two or more parts and 10-150mm length, suitable as clothes and hardly causing mesh slippage.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a novel nonwoven fabric and a method for producing the same. More specifically, a novel nonwoven fabric suitable for general clothing, which is formed by three-dimensionally intertwining a plurality of fibers with a continuous fiber length distribution and fibrillated tips, and an industrial method for manufacturing the same. Regarding.

[Prior Art] Methods for producing nonwoven fabrics made of short fibers are roughly divided into three types depending on the length of the fibers that make up the nonwoven fabric. The first is
This is a method of obtaining a nonwoven fabric by opening and laminating fibers having a fiber length of 30III11 or more using a roller card or the like, and bonding them with heat-sealable fibers or resin, or by entangling the fibers with a high-pressure water column flow.

The second method is to obtain a nonwoven fabric by wet-forming fibers having a fiber length of less than 100 g and adhering them with a resin, or by entangling the fibers with a high-pressure water column flow. The thirteenth method is a method in which a two-layer structure consisting of a wood valve layer and a synthetic fiber layer is entangled by a high-pressure water column flow. 9
It is disclosed in Japanese Patent No. 4659.

[Problem to be solved by the invention]

However, when the nonwoven fabric obtained by the first method is used for products with a basis weight of 100 g/n or less as a nonwoven fabric for general clothing, the effect of developing anisotropy by the roller card method is large, and the nonwoven fabric properties cannot be improved. @1/transverse strength ratio of the nonwoven fabric shown (Hereinafter, the longitudinal/transverse strength ratio of the nonwoven fabric is expressed by the dispersion orientation index R in the plane direction of the nonwoven fabric measured by microwave measurement.)
In the case of R=3 to 10, the strength in the lateral direction was extremely low during actual use, and there was a problem that the range of use was limited. In addition, in the second method, the orientation property is relatively good with R = 1 to 3, but due to the entanglement of short fibers of 10[l1m or less and the influence of the resin, the texture is stiff, and only vapor-like products can be produced. Not suitable for use.

Furthermore, in the third method, because the obtained nonwoven fabric has a layer consisting of wood bulbs on one side, that is, because extremely short fibers are used, fuzzing and fiber shedding are likely to occur. There was a problem that the process was complicated.

An object of the present invention is to provide a nonwoven fabric that has a uniform dispersion orientation index of fibers in the nonwoven fabric, has excellent flexibility and bulkiness, and can be used for general clothing. The present invention also solves problems such as complicated manufacturing process, upper limit of cost, uniform dispersion of fibers, and manufacturing of a web with a low basis weight that occur when manufacturing this type of nonwoven fabric conventionally known. The purpose of the present invention is to provide a method for inexpensively producing a nonwoven fabric that can be used for general clothing, and has a uniform fiber orientation index and excellent flexibility and bulk.

[Means for Solving the Problems] A first object of the present invention is to provide fibers with a length of 1O to L5Q+1.
It is formed by three-dimensionally intertwining each other with a plurality of fibers that are continuously distributed in the mLy′) range and have at least two or more fibrillated ends on the -· side, and are formed by intertwining each other three-dimensionally. This is achieved by a novel nonwoven fabric characterized by a dispersion orientation index R in the range of 0.8 to 1.3.

The nonwoven fabric of the present invention requires that the fiber length distribution of the fibers constituting the nonwoven fabric is continuous in the range of 10 to 150 m, and that at least one tip of the fiber is fibrillated into two or more fibers. It is. In other words, it has a continuous fiber length distribution that could not be achieved with conventional methods, and because the tips are fibrillated into two or more fibers, the high-pressure water column flow highly enhances fiber entanglement, and the entangled ends The resulting nonwoven fabric has sufficient physical properties for use in general clothing, being soft, bulky, and resistant to shedding.

The three-dimensional entanglement in the nonwoven fabric of the present invention is maintained by the high-pressure water column flow.

When three-dimensional entanglement is effected by applying an action such as a high-pressure water column flow, the three-dimensional entanglement is more advanced than when simply using needles. In other words, the above-mentioned fibers constituting the nonwoven fabric are three-dimensionally entangled by hydroentanglement, so that the fibers in the relatively long region of the fiber length distribution maintain flexibility and bulk, and the fibers in the relatively short region maintain their flexibility and bulk. As a result, a higher level of fiber entanglement occurs, and furthermore, the fibrillated fibers further enhance the entanglement between both fibers, resulting in sufficient physical properties for use in clothing.

Here, if the fiber length is shorter than 10 mm, it is not preferable that many short fibers fall off during high-pressure water column flow treatment. Moreover, if the fiber length is longer than L 50 mm, troubles such as winding around a combing roller used in the production method of the present invention, which will be described later, occur, which is not preferable.

In addition, without using three-dimensional entanglement due to high-pressure water column flow, the form of a nonwoven fabric can be obtained by bonding multiple fibers having the fiber length distribution and tip shape described in 111 using heat-fused fibers or resin. Although it can be formed, 3
Since the dimensional entanglement is not completed, delamination between the laminated nonwovens 41 does not occur, and the texture becomes stiff, which is not preferable for use in general clothing.

The nonwoven fabric of the present invention has a dispersion orientation index R of 0.
It needs to be in the range of 8 to 1.3.

The dispersion orientation index R is a value obtained by measuring the orientation distribution of the fibers constituting the nonwoven fabric using microwaves and expressed as the strength ratio in the shrinkage direction and the transverse direction of the nonwoven fabric (the measurement method will be described later).

When R is outside the range of 0.8 to 1.3, the nonwoven fabric will have strong anisotropy in the vertical direction (R>1.3) or the horizontal direction (R<0.8), making it suitable for general clothing. For practical use, this is not preferable because it limits the sewing direction and the area in which it can be used.

The fibers constituting the nonwoven fabric of the present invention are not particularly limited, but by mainly using acrylic fibers,
The flexibility and texture of acrylic fibers themselves,
It exhibits the best performance as a nonwoven fabric for general clothing in terms of bulk, excellent color development, and weather resistance. As the acrylic fiber, any commercially available acrylic fiber may be used, such as acrylic fibers used for knitwear, interior decoration, bedding, carpets, shoe bottoms, etc., and flame retardant (LOI 28 to 33). Acrylic fibers are used for curtains, carpets, etc.

Furthermore, if heat-resistant, high-strength acrylic fibers are used, they can be used not only for general clothing but also as nonwoven fabrics for materials. Furthermore, the acrylic fibers may be colored by adding dyes or pigments before being made into a non-woven fabric.

The method for producing a nonwoven fabric of the present invention is to produce a continuous fiber bundle in the form of a multifilament or tow at a surface speed of 1000 m/mi.
The fibers are cut and dispersed with a needle roller rotating at n or more, and the cut and dispersed fibers are continuously laminated on a net with a dispersion orientation index R in the range of 0.8 to 1.3 while being exposed to turbulence. fleece, then 10~look/c
The fleece-like fibers are three-dimensionally entangled with at least one stage of high-pressure water column flow having a water pressure of ta G.

Although the nonwoven fabric manufacturing method of the present invention has the advantage of being able to utilize known fibers, it is an epoch-making method that simultaneously combines the following three features that could not be achieved with conventional nonwoven fabric manufacturing methods. That is, (1) A continuous fiber length distribution of 10 to 150 mm can be created in one step.

■ At least one fiber tip can be fibrillated into two or more fibers.

■ The strength distribution of the non-woven fabric is uniform and there is no delamination.

It has the following characteristics. Below, the industrially useful manufacturing method of the nonwoven fabric of the present invention will be explained in detail using one embodiment shown in the drawings.

FIG. 1 is a side view showing an example of an apparatus for carrying out the manufacturing method of the present invention. In FIG. 1, the fiber bundle 1 may be an aggregate of continuous filament-like materials having a size of several tens to several thousand deniers, or may be a continuous fiber having crimps of several tens to several thousand deniers (generally a tow-like material). It may be a collection of (called).

The amount of the fiber bundle 1 fed into the nip rolls 2 and 3 can be arbitrarily selected depending on the diameter of the combing roller 4 and the clothing. In addition, by setting the speed ratio of the two rollers 2 and 3 to approximately 1:1.2, the manner in which the fiber bundle is fed to the combing roller 4 is improved. The combing roller 4 may have any structure as long as it has a plurality of opening cloths on its surface, as conventionally used in the spinning process, but it may have any structure as described in Japanese Patent Application Laid-Open No. 59-116.
It is more effective to use the needle blade roll disclosed in Japanese Patent No. 462.

The combing roller 4 needs to rotate at a surface speed of 1000 m/min or more. That is, if the surface velocity is 10
When the speed becomes lower than 00m/min, the combing roller-4
The cutting and dispersion effect between the combing roller 3 and the nip roller 3 is extremely reduced, and fibers with extremely long fiber lengths and fibers often winding around the combing roller 4 occur, which is not preferable.

The surface speed of combing roller 4 is 1000m/min
Above, preferably 1000m/min to 5000m/min
m/mtn. The diameter of the combing roller is preferably 5 to 50+·1nφ, and the length of the needle blade is 0.5 to 10 m.
It is m.

The fibers cut and dispersed by the combing roll 4 are transported to the wind tunnel section 6.
is released. In the apparatus shown in FIG. 1, a vacuum device 9 is disposed below the wind tunnel section 6 and is driven by a drive roll 14 as shown. Therefore, the fibers 7 in the wind tunnel section 6 are sucked downward. At this time, turbulence is generated in the wind tunnel section 6 by the suction air flow and the discharge air flow of the combing roll 4, and the fibers 7 are more uniformly dispersed by the turbulence and are sucked and dropped onto the net combing hair 15.

In order to more effectively generate the turbulence, it is preferable to provide a damper 5 at the top of the wind tunnel section 6 to separate the incoming air into two directions (1) and (2). By appropriately adjusting the suction air flow and other conditions, the fibers 7 are more preferably 3 to 10
Suction into the net conveyor 15 at a falling speed of m/sec.
Laminated. Here, the falling speed of the fibers is not particularly limited, but is preferably 3 to rom/sec. If the falling speed of the fibers 7 obtained by the air flow is slower than 3 m/sec, the stacking on the net conveyor 15 will be uneven, and the dispersion orientation index R in the plane direction of the obtained fleece-like material f will be 0. It shows a range of 5 to 4.0, which is not preferable because stable lamination cannot be achieved. In addition, even if the falling speed is faster than 10HI/5 (4C), especially the obtained fleece-like material r
R can satisfy the scope of the present invention, but the amount of energy required for suction is large, and the fiber net conveyor 1
5. This is not preferable as it may cause problems due to biting into the upper part.

The stability diagrams of the fleece-like material [and the nonwoven fabric W] obtained in Example 1, which is an example of the embodiment of the present invention, are shown by the solid line (■) and the broken line (■) in FIG. 2, respectively. 2 and 2 in FIG. 2 indicate that the fiber length distribution obtained by suction and lamination is maintained almost unchanged even after the high-pressure water column flow and drying steps.

Further, the dispersion orientation index R of the fleece-like material f and the nonwoven fabric W in the planar direction is l, respectively. 01, 1.02, and the dispersion orientation behavior in the plane direction of the fibers obtained by suction lamination is maintained almost unchanged even after high-pressure water column flow and drying (°?). It shows.

The nonwoven fabric of the present invention is applied to the high-pressure water column flow imparting device 10 in FIG.
11.12 enables three-dimensional confounding. FIG. 3 schematically shows a cross-sectional view of a nonwoven fabric obtained by changing the pressure of a high-pressure water column flow on the fleece-like material f. O in FIG. 3 is a sectional view of a fleece-like material f obtained in Example 1, which will be described later, and ◎ is a sectional view of a nonwoven fabric W obtained in Example 1. In addition, ■ is the nonwoven fabric f obtained in Example 2 described below.
FIG. 2 is a cross-sectional view showing that the surface form of the nonwoven fabric obtained by subjecting the fleece-like material W to an intertwining treatment by changing the pressure of a high-pressure water column flow can be arbitrarily changed.

The pressure of high-pressure water column flow is 10-100 kg/cJ
If it is within the range of G, it can be selected arbitrarily, but columnar flow device 1
When using three 0°11 and 12 as shown in Fig. 1, the pressure is increased from 10° to 12° in order from upstream. 30 kg/
cIG, 20-50kg/cTAG, 30-100k
It is best to define it as g/call G. However, regarding pressure distribution, the surface morphology of the nonwoven fabric can be changed arbitrarily.
In order to adapt to market demands, the above is not limited and any changes may be made; however, in the end, the nonwoven fabric 1;
The pressure of the given columnar flow is 10 to 100 kg/c G,
More preferably 30-80 kg/call G
It is.

However, FIG. 1 shows only one embodiment of the present invention, and the entangling method using the high-pressure water column flow is not limited to the devices 10 and 11.
, 12 and the naction box 13 are not limited to the combination and shape.

The fleece-like material three-dimensionally entangled by the high-pressure water column flow is transferred to a dryer 17 by a nip roll 16, passed through the nip roll 18, and wound up on a take-up roll 20 as the nonwoven fabric C1 of the present invention.

Dry Ja%lff117 is not particularly limited, but it is preferable to use a pin tenter dryer or the like using hot air at 70 to 150°C.

(Example) Next, Examples of the present invention will be described to further explain the present invention in detail. Prior to describing the examples, a method for measuring characteristic values used here will be described.

Mark: 250mm from the 1g sample
Collect 3 samples of 250nun and calculate water molecule jki
After reaching this state, the weight (1()) is weighed and the average value is expressed as per unit area (g/m).

Strength and elongation was measured according to JIS-L-1068. Expressed in strength (kg/5 cm width) and elongation (%).

Dispersion orientation index: A 10 cm x 10 cm sample was taken from a sample in a standard state using a microwave molecular orientation meter manufactured by Kanzaki Seizi Co., Ltd., and the frequency was 3.
The orientation intensity ratio in the plane direction of the sample was calculated at 98C; Hz and was defined as R (dispersed orientation index).

Tear strength, measured according to JIS-L-1085, (
expressed in kg).

Using the apparatus shown in FIG. 1, a nonwoven fabric of the present invention was obtained under the conditions shown below. Table 1 shows the basis weight, strength and elongation, and dispersion orientation index R. The stability diagrams of the obtained fleece-like material f and nonwoven fabric W were measured by a conventional method and are shown in FIG. The shape of the tip 7a of the fiber 7 obtained in FIG. 1f is schematically shown in FIG. 3. Also, fleece-like material
A schematic cross-sectional view of the nonwoven fabric W is shown in FIG. 4 by O and ◎. As shown in Figure 4 O, the fleece-like material f has a layered laminated structure, and as shown in Figure 4 ◎, in the nonwoven fabric W, the fibers are highly three-dimensional due to the action of the high-pressure water column flow. Showing confounding. Furthermore, as shown in Figure 2 (■) and (2), it can be seen that the staple diagram of the fibers hardly changes before and after the treatment with the high-pressure water column flow. However, the average fiber length of the fibers in the fleece material (1) is 40.5 mm, and the average fiber length of the fibers in the nonwoven fabric (2) is 39.8 mm.

The operating conditions for the apparatus shown in FIG. 1 are now set forth below in comparison with the reference numerals in FIG.

l (Reference number, same below) ... Cashmilon @1.2'3. Acrylic fiber of O million denier (manufactured by Asahi Kasei Corporation) 2.3...Nip roll feeding speed 4 m/min/4
, 1 m 7m1n 4...Combing roller B 20 canφ surface speed 3000 nights 11 fabric length 2 +++++n 6...Fiber falling speed 6m/m1n 10, 11, 12...High pressure water column flow device orifice diameter 0 .15mmφ Processing density 15hole/cmX 3 times processing pressure
No, 10 15kg/cJGNo, 11 25
kg/crAG No., 12 40kg/c+flG 15...70 mesh stainless steel belt running speed 10m/m1n 17...Drying temperature of dryer 90°C 20... Winding speed of take-up roll 10m/min Emergency facility l In the equipment shown in Figure 1, the columnar flow device 10 is not used, and the processing pressures 11 and 12 are each 40 kg/ct.
A nonwoven fabric was obtained in the same manner as in Example 1, except that the weight was 70 kg/c++IG. The results are shown in Table 1, and a schematic diagram of the cross section of the nonwoven fabric is shown in Figure 4 (■).

Table 1: Measure the dispersion orientation index R of a commercially available nonwoven fabric for clothing (cart type) with a basis weight of 40 to 50 g/rrr, and measure the tear strength of the nonwoven fabric, which is one of the functions required when wearing clothing.
A comparison was made with the nonwoven fabrics obtained in Examples 1 and 2. The results are shown in Table 2.

Using the apparatus shown in Table 1, the surface speed of the combing roller 4, the fiber falling speed in the wind tunnel section, and the high pressure water column flow treatment pressure under the conditions shown in Example 1 are shown in Table 3. Various nonwoven fabrics were obtained by making changes as shown in . The basis weight, dispersion orientation index R, and processability of the nonwoven fabric were evaluated, and the results are shown in Table 3.

〔Effect of the invention〕

The nonwoven fabric of the present invention has superior isotropy in physical properties compared to conventional products commercially available for general clothing, and can be used as a nonwoven fabric for general clothing that has the advantages of flexibility and bulkiness originally found in acrylic fibers. An optimal nonwoven fabric can be provided. Furthermore, the nonwoven fabric manufacturing method of the present invention is inexpensive,
It is possible to provide an industrial manufacturing method for high-performance nonwoven fabrics.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating an embodiment of an apparatus for carrying out the method for producing a nonwoven fabric of the present invention, and FIG. 2 is a staple diagram diagram showing an example of fiber length distribution of fibers constituting the nonwoven fabric of the present invention. FIG. 3 is a schematic diagram showing fibrillation at the tips of cut and dispersed fibers, and FIG. 4 is a schematic cross-sectional diagram showing the intertwining form of fibers in the manufacturing process of the nonwoven fabric of the present invention. ■... Supply tow, 4... Combing roller 6... Wind tunnel section, 9... Vacuum device,
10.11.12... High pressure water column flow device, 15...
Net conveyor, 17... Dryer, f... Fleece-like material, 20... Winding roll, W... Nonwoven fabric.

Claims (3)

[Claims] 1. A fiber is formed by three-dimensionally intertwining each other with a plurality of fibers whose lengths are continuously distributed in the range of 10 to 150 mm, and at least one of the fibers has two or more fibrillated ends. The dispersion orientation index R in the plane direction is 0.
．． A novel nonwoven fabric characterized in that it has a molecular weight in the range of 8 to 1.3. 2. The novel nonwoven fabric according to claim 1, wherein the fibers are acrylic fibers. 3. A continuous fiber bundle in the form of a multifilament or a tow is cut and dispersed with a needle roller rotating at a surface speed of 1000 m/min or more, and the plurality of cut and dispersed fibers are exposed to turbulence and dispersed onto a net with an orientation index R. is 0.
Continuously laminated in the range of 8 to 1.3 to form a fleece,
A novel method for producing a nonwoven fabric, characterized in that the fleece-like fibers are then three-dimensionally entangled in at least one stage of high-pressure water column flow having a water pressure of 10 to 100 kg/cm^2G.