JPH0465567A - Nonwoven fabric and production thereof - Google Patents

Abstract

PURPOSE:To obtain a nonwoven fabric having pliant hand and a high tear strength by forming specific split type conjugate fiber into a tow, drawing and crimping the two, providing a tow web, subjecting the resultant web to treatment with a high-pressure liquid stream under special conditions, simultaneously splitting the fiber into superfine fibers and entangling the split fibers. CONSTITUTION:Split type conjugate fiber composed of >=2 mutually incompatible components is melt extruded, spun and bundled to provide a two, which is then drawn and crimped. The resultant tow is subsequently formed into a two web having 30-200g/m<2> basis weight with a separating guide. The formed tow web is then loosened on a conveyor belt by increasing the speed thereof from the running speed of the conveyor belt by 1-5% and subjected to treatment with a high-pressure liquid stream to split >=0.5 denier. The respective fibers are mutually entangled to form a nonwoven fabric.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a nonwoven fabric and a method for producing the same.
More specifically, the present invention relates to a flexible and strong nonwoven fabric in which the tow containing at least a portion of ultrafine fibers has an intertwined structure, and a method for producing the same.

(Prior Art) Conventionally, there has been a demand for a nonwoven fabric that has the characteristics of having a soft texture, strong tear strength, and resistance to fluffing, but it has not been possible to obtain a nonwoven fabric that is satisfactory.

For example, Japanese Patent Application Laid-Open No. 62-268861 discloses that split type composite I/ij I fibers are divided in the step of applying mechanical crimp after drawing, and after being made into a web using a card machine, a high-pressure liquid stream is injected. There is a method for producing an entangled non-woven fabric, and Japanese Patent Application Laid-Open No. 63-219653 discloses a method of forming a multi-component composite filament web, dividing the web and then jetting a high-pressure liquid stream to entangle it, or jetting a high-pressure liquid stream. A split and entangled ultrafine multifilament nonwoven fabric and a method for making the same are described.

(Problems to be Solved by the Invention) In the conventional manufacturing method in which splittable composite lIj! fibers are divided by mechanical crimping and made into cards and nonwoven fabrics through the process of high-pressure liquid flow,
Because the ultrafine fibers are passed through a carding machine, the carded web becomes uneven and has poor texture, resulting in the finished nonwoven fabric having a strongly uneven texture.

In addition, since each single filament is straight in a nonwoven fabric made of ultra-fine multifilaments, the degree of entanglement is weak even when entangled with a high-pressure liquid flow, and the texture is flexible, but the strength is weak. The object of the present invention is to solve the above-mentioned problems and provide a nonwoven fabric that has a soft texture, strong tear strength, and no wings, and a method for producing the same.

(Means for Solving Problem Y) A first aspect of the present invention is a nonwoven fabric composed of a splittable conjugate fiber tow made of at least two or more components that are incompatible with each other, % or more, the composite fiber is 0.
Ultrafine fibers are divided into pieces of 5 deniers or less, and the ultrafine fibers are intertwined with each other, the ultrafine fibers and composite fibers, and the composite fibers are randomly intertwined in a three-dimensional manner.If the longitudinal direction of the nonwoven fabric is taken as the vertical direction, the fibers are mainly in the vertical direction. However, at least some of the fibers are arranged diagonally or horizontally, and when the thickness of the nonwoven fabric is set at different levels, some fibers are arranged at the same level, while others are arranged at various levels. It is a non-woven fabric characterized by being intertwined in a mixed form with a non-woven fabric existing at different levels. The fibers are thermally sprayed and extruded and spun to form a tow. After stretching, the crimped tow is made into a tow web with a basis weight of 30 to 200 g/m2 using a fiber splitting guide, and the tow web is subjected to high-pressure liquid temperature treatment on a conveyor belt. When dividing 10% by weight or more of the composite fibers into ultrafine fibers of 0.5 denier or less and intertwining each fiber to form a nonwoven fabric, the tow web feeding speed to the conveyor belt is set to 1 to 5 times higher than the running speed of the conveyor belt. % and loosens the tow web.

In the present invention, the cross-sectional shape of the splittable conjugate fiber is not particularly limited, but as an example, those shown in FIGS. 2 and 3 are used. The material may be any material that can form fibers, such as polyethylene, polypropylene, polymethylpentene, ethylene-vinyl alcohol copolymer,
Polyolefins such as ethylene-vinyl acetate copolymer,
Two or more types can be selected from polymers or copolymers such as polyester, polyamide, and polyvinyl chloride. The splittable composite fiber obtained by melt composite extrusion spinning using the above-mentioned cross-sectional shape and material is stretched in hot water, boiling water, steam, heated gas, or in contact with a heating body, and after being attached with an oil agent, the fiber is drawn for 10 to 17 days. The tow is mechanically crimped and passed through a dryer, and the tow is stored in a canister. Here, the number of crimps is 10/i
If it is less than n, the entanglement will be weak during high-pressure liquid temperature treatment, and a strong nonwoven fabric will not be obtained. If the number of crimps is more than 17 crimps/in, the tangles will be strong and a uniform nonwoven fabric will not be obtained.

Next, the drawn yarn tow of the splittable conjugate fiber is divided into fibers by a fiber separation guide so as to have a basis weight of 30 to 200 g/m2. If the basis weight is less than 30 g/m2, the high-speed liquid treatment will cause unevenness in the texture of the nonwoven fabric, leading to uneven texture.If the basis weight is greater than 200 g/m2, it will be difficult for the high-pressure liquid flow to pass through. Separation and entanglement are incomplete, and the desired texture and strength cannot be obtained.The drawn yarn tow of the splittable composite fiber with the above basis weight is loosened by 1 to 5%, and the water pressure is 60 to 200 kg/cof, and the conveyor speed is 5 to 5%.
By performing high-pressure liquid temperature treatment at 101/-, the splittable composite fibers are split into ultrafine fibers of 10% by weight or more and 0.5 denier or less. The fibers are randomly intertwined in a three-dimensional manner, and when the longitudinal direction of the nonwoven fabric is taken as vertical, the fibers are mainly arranged in the vertical direction, but the fibers arranged in the diagonal and horizontal directions are at least at the same level. It is a mixture of things that exist at different levels and things that exist at various levels.

If the slack of the drawn yarn tow of the splittable composite fiber is less than 1%, the fibers will be split, but the intertwining of the fibers will be insufficient and the desired nonwoven fabric will not be obtained.If the slack is more than 5%, the drawn yarn tow will be It swells from side to side, creating gaps between the fibers, through which the high-pressure liquid flow passes, resulting in insufficient division and entanglement of the fibers, making it impossible to obtain the desired nonwoven fabric.

The water pressure of the high-pressure liquid flow is 60 kg/an (if it is less than 60 kg/an, the separation and entanglement will be insufficient, and the water pressure will be 200 kg/cnf).
If the size is larger, there will be no particular problem, but it will lead to oversupply and become an economic problem. If the conveyor speed is less than 5 m/yia, productivity will be poor, and if the conveyor speed is faster than Ion/mix, division and entanglement will be insufficient. Further, the high pressure liquid temperature treatment is preferably repeated 3 to 10 times in order to obtain the desired nonwoven fabric.

Ultra-fine fibers split from composite fibers by high-pressure liquid temperature treatment
If the content is less than 0% by weight or the thickness of the ultrafine fibers is greater than 0.5 denier, a soft texture cannot be obtained.

(Function of the invention) The present invention mechanically crimps a splittable composite fiber tow, passes it through a splitting guide during high-pressure liquid temperature treatment to obtain the desired weight, and loosens the tow to ensure sufficient splitting and entanglement. , it is possible to obtain the desired nonwoven fabric with a soft texture and strong tear strength.

Hereinafter, embodiments will be explained based on the drawings.

(Example) FIG. 1 is a schematic view showing the manufacturing process of the nonwoven fabric of the present invention, and FIGS. 2 and 3 are examples of fiber cross-sectional views of splittable conjugate fibers.

Using splittable composite fibers with the fiber cross-sectional shape shown in Figure 2, polypropylene was used as component A (10) and ethylene-vinyl alcohol copolymer was used as component B (11), melt composite extrusion spinning was carried out. A drawn yarn was obtained. This undrawn tow was drawn 4.6 times using a 150"C dry drawing machine, and after being coated with an oil agent, it was mechanically crimped at a rate of 16 crimps per inch. After drying, it was made into a 3 denier drawn yarn with a total denier of 80,000 denier. The composite fiber tow (3) was placed in a can.

This composite fiber drawn yarn (1) is divided into 2 parts by a fiber splitting guide (2).
Separated into 0 fibers, basis weight 120 g/rr? Tow web (
3), when the tow web (3) is fed onto the conveyor belt (7) by the feed roll (4), the rotational speed of the feed roll (4) is made 1% faster than the running speed of the conveyor belt (7). relaxed. In the high-pressure liquid processing device (5), the nozzle (6) has a hole diameter of 0.1 amφ, a distance between hole centers of 4 mm, a hole arrangement of two rows, and a hole arrangement direction of 90° with respect to the traveling direction of the tow web (3). A nozzle (6) with an amplitude of 2C11, a frequency of 100 cycles, a water pressure of 60 kg/atl and a conveyor belt (7) speed of 1 were used in this device.
The high pressure liquid flow (8) treatment was carried out 5 times at m/m.

As a result, a nonwoven fabric (9) containing 95% by weight of ultrafine fibers of about 0.4 denier by splitting the splittable conjugate fibers and having a soft texture and high tear strength in a sufficiently entangled state was obtained.

(Comparative Example) As a result of performing the same procedure as in the example except that the tow web (3) was subjected to a high-pressure liquid flow (8) in a tensioned state without applying mechanical crimping, the splittable composite fiber obtained ultrafine fibers in the same manner as in the example. However, the entanglement was insufficient, resulting in a nonwoven fabric with a soft texture but weak tear strength.

<Effects of the Invention> The nonwoven fabric of the present invention has a soft texture and excellent tear strength, and can be used in a wide range of fields such as artificial leather, clothing, interior decoration, wipers, and filters. However, it is particularly suitable as a base material for clothing.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the manufacturing process of the nonwoven fabric of the present invention. FIG. 2.3 is a cross-sectional view showing an example of the splittable conjugate fiber used in the present invention. In the figure, 1: composite fiber tow 2: splitting guide 3: tow web 4: supply roll 5: high pressure liquid treatment device 6: nozzle 7: conveyor belt 8: high pressure liquid flow 9: nonwoven fabric
10: A component 11: B component

Claims (2)

[Claims] (1) A nonwoven fabric composed of a splittable conjugate fiber tow consisting of at least two or more mutually incompatible components, in which 10% by weight or more of the tow consists of ultrafine fibers in which the conjugate fibers are split into pieces of 0.5 denier or less. Yes, ultrafine fibers are intertwined with each other, ultrafine fibers and composite fibers, and composite fibers are randomly intertwined with each other in a three-dimensional manner.If the longitudinal direction of the nonwoven fabric is vertical, the fibers are mainly arranged in the vertical direction, but in the diagonal direction, At least some of the fibers were arranged in the lateral direction, and when the thickness of the nonwoven fabric was set at different levels, some fibers were present at the same level and some were present at various levels. A nonwoven fabric characterized by being intertwined in shape. (2) splittable composite fibers made of at least two or more mutually incompatible components are melt-extruded and spun into a tow;
After stretching, the crimped tow is divided into fibers with a fabric weight of 30.
~200 g/m^2 tow web and high pressure liquid flow treatment on a conveyor belt to form composite fibers of 10
When dividing % by weight or more into ultrafine fibers of 0.5 denier or less and intertwining each fiber to form a nonwoven fabric, the tow web feeding speed to the conveyor belt is 1 to 5% higher than the running speed of the conveyor belt. A method for producing a nonwoven fabric, characterized by loosening a tow web on a conveyor belt.