JPH04257359A - Production of split nonwoven fabric - Google Patents

Abstract

PURPOSE:To readily produce a nonwoven fabric of ultrafine fiber optimum as a filter, wiper, etc., using an ordinary card machine and a water jet machine. CONSTITUTION:A conjugate synthetic fiber capable of splitting is carded to form a web containing split fiber and then the conjugate synthetic fiber is further split with a water jet, and simultaneously, fibers of the above-mentioned web is mutually interlaced and part of the split nonwoven fabric is thermally fused. Thereby, a split nonwoven fabric having good process-passing property and containing uniform ultrafine fiber is readily obtained, and the resultant split nonwoven fabric contains 10-80wt.% fiber having <=0.5 denier fineness and has excellent physical properties such as feeling by hand and air diffusibility in addition to excellent cloth strength, and is suitable for filter, wiper, base for artificial leather, etc.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing nonwoven fabrics using ultrafine fibers used in filters, wipers, interior products, etc.

0002

[Prior Art] Conventionally, in order to obtain non-woven fabrics made of ultrafine fibers (0.8 denier or less), one of the following methods has been adopted: a papermaking method, a melt blow method, or a precision card machine. was.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned papermaking method, short fibers of 10 mm or less are used and based on the fabric structure, the strength of the fabric obtained is not sufficient, so it is difficult to fix the fabric by using a binder or the like. This has the disadvantage of complicating the process and increasing costs. Further, although ultrafine fibers can be easily obtained using the melt blowing method, there are various problems in that the fabric strength is not sufficient and that it requires investment in equipment. Furthermore, in the method using the above-mentioned precision card, the minimum fineness limit is usually 0.8.
The present situation is that it is extremely difficult to form a homogeneous web with ultrafine fibers having a denier of about 0.5 denier or less.

The present invention has been devised in view of the various drawbacks of the prior art, and its purpose is to easily produce ultrafine fibers using conventional carding machines and water jet machines without hindering the carding action. Get the filter,
The purpose of the present invention is to provide a method for manufacturing a nonwoven fabric suitable for wipers and the like.

[0005]

[Means for Solving the Problems] The gist of the present invention is to form a web containing splittable fibers by carding splittable composite synthetic fibers, and then further split the splittable composite fibers using a water jet. At the same time, the fibers constituting the web are intertwined with each other to produce a split-fiber nonwoven fabric.

The obtained split nonwoven fabric is a split nonwoven fabric containing 10 to 80% (by weight) of fibers of 0.5 denier or less, and after forming the split nonwoven fabric by entangling with a water jet, the split nonwoven fabric is By heat-sealing a part of the fibers, a split nonwoven fabric with even higher fabric strength can be obtained.

[0007]

[Function] Hereinafter, the present invention will be explained in more detail focusing on the function. The method for producing a split-fibre nonwoven fabric of the present invention involves pre-spinning composite fibers so that the composite synthetic fibers are split by mechanical action in the longitudinal direction; Cut this into the required short fibers. When using a commonly used card for cotton or worsted to obtain the desired fiber web, some of the composite synthetic fibers are split in the longitudinal direction by the opening and drafting action of the card to produce split fibers. The fibers are formed, and some of them are in a state where they are extremely easy to split. Next, when applying an entangling action using a water jet, the composite synthetic fibers, which are in a state where they are extremely easy to split, are split by the impact force of the water jet. Therefore, by the synergistic action of the card and the water jet, split fibers are formed and the desired nonwoven fabric is formed while ensuring the strength of the fabric.

[0008] The composite synthetic fiber used in the present invention is preliminarily coated with 0.
It must be designed to split to 5 denier or less. The cross-sectional shape of the split fibers is not particularly limited. Generally, shapes include round, oval, wedge, rectangular, triangular, and combinations thereof. Further, the composite component polymers may be of the same type, the same family, or a combination of different polymers, but in order to obtain split fibers relatively easily, a combination of different polymers is generally used.

Furthermore, it is not necessary to split all the composite synthetic fibers to 0.5 denier or less, and it is necessary to determine the fineness ratio depending on the intended use of the nonwoven fabric. Moreover, the splitting state may be such that a part of the composite synthetic fiber is split along the longitudinal direction and a part of the composite synthetic fiber is not split.

The split nonwoven fabric of the present invention must contain 10 to 80% (by weight) split fibers of 0.5 denier or less. If it is less than 10% (by weight), it is within the range of commonly obtained dry nonwoven fabrics and does not have any special features. That is, 10% (
Weight) or more, it is possible to obtain a dense nonwoven fabric with unprecedented drapability and air permeability.

[0011] In addition, if it is more than 80% (weight), a large load will be placed on the carding process, and at the same time, fibers of less than 0.5 denier will sink into the clothing, causing problems in the process such as the generation of neps. occurs, which is unfavorable in terms of manufacturing.

[0012] In the method for producing split-fiber nonwoven fabric of the present invention, the denier of split-fibre fibers is set to 0.5 denier or less by:
If the fiber has a denier of 0.5 or more, the nonwoven fabric targeted by the present invention cannot be obtained, and as described above, it is necessary to contain fibers of a denier of 0.5 or less. In other words, by using fibers of 0.5 denier or less, it is possible to have unprecedented drapeability, softness, and denseness, as well as filtering properties and water retention properties.

[0013] There is no particular restriction on the denier below 0.5 denier, but in the present invention, in order to employ the card method, it is preferable to use a split-fiber nonwoven fabric mainly composed of split-fibre fibers of 0.1 to 0.4 denier. Good to manufacture.

As described above, the present invention uses a composite synthetic fiber designed to be splittable in order to obtain splittable fibers, and this is used in the carding and water jet processes.
It becomes split fibers by carding and water jet opening action and impact force. This means that if you rely only on carding for the splitting effect, the carding effect will be excessive, causing not only the splitting effect but also fiber breakage and sinking of the ultrafine fibers into the clothing, making it difficult to obtain a good web. This is important in order to avoid the range of conditions being extremely limited. Therefore, the splitting state during carding is set to normal carding conditions to avoid the above-mentioned troubles, and the insufficiently splitting composite synthetic fibers are split using the impact force of a water jet while the entangling effect is applied. The manufacturing method of the present invention is characterized by this process.

Next, the present invention will be described in which a portion of the nonwoven fabric obtained as described above is heat-sealed. As described above, it is useful to form a split nonwoven fabric by entangling the fibers with each other by water jet action, and then heat-seal a portion of the nonwoven fabric.

[0016] As the method of thermal fusion, a commonly used method using an oven-type processing machine or a calender can be employed.

In the method of the present invention, in order to use a splittable composite synthetic fiber, it is possible to select a fiber having a lower melting point than the other components as one of the constituent components of the fiber. If synthetic fibers are heat-sealed to match the low melting point, only the low-melting point fibers of the composite synthetic fibers will be melted and heat-sealed, reducing the area to be heat-sealed as a whole. It becomes possible to improve the stability of the form and the strength of the fabric, which are the main objectives of the present invention, without impairing the feel even when worn, making it a more useful method. The method and degree of thermal fusion are not particularly limited, and may be appropriately selected depending on the purpose of use.

[0018]

[Examples] The present invention will be explained in detail with reference to Examples below, but the present invention is not limited to the Examples described below. In addition, measurements of various physical properties in the following examples were performed by the following methods. Thickness: Fabric thickness gauge (manufactured by Techlock) Pressure:
120g/3.14cm2 Air permeability: JIS L
-1096L (Frazier method) Splitting ratio: Based on a scanning electron microscope of a cross section of a nonwoven fabric. Strength: 5 cm wide strength, constant speed medium length tensile tester (Example 1) A split nonwoven fabric was formed under the following conditions. (1) Composite synthetic fiber (2.5 d) combination polymer,
Polypropylene/Polyester split denier and shape Polypropylene, wedge-shaped 0.11 d Polyester, oval 0.3 d (2) Card machine Flat card for cotton, number of cylinder points 800 cylinders 250 r. p. m. Spinning speed: 15 m/min Web weight: 6 g/m2 The obtained web was laminated with a cross wrapper to form a laminated web of 60 g/m2, and then subjected to a water jet to obtain a split nonwoven fabric. (3) Water jet machine conditions Web speed 15.5 m/min Water jet machine nozzle diameter and number, water pressure nozzle diameter 0.15 m/m 2 nozzles 30 kg/cm
2 nozzle diameter 0.15m/m 1 piece 60
kg/cm2 Nozzle diameter 0.12m/m 1
Book 80kg/cm2 screen
Stainless steel 80 mesh The resulting split-fiber nonwoven fabric has a thickness of 0.45m/m and a strong vertical strength of 13.6k.
g/5cm (vertical), 13.0kg/5cm (horizontal),
The airflow rate is 0.5 with a performance of 54cc/cm2/sec.
The proportion (weight) of split fibers of denier or less was 43.8%, making it suitable for use in various filters and wipers.

(Example 2) The split nonwoven fabric obtained in Example 1 was heat treated under the following conditions. Emboss calendar pressure 10kg/cm, temperature 1
80℃ convex shape 0.5m/m x 0.8m/m
The split nonwoven fabric obtained with a presser ratio of 15% has a thickness of 0.43 m/m and a strength of 15.4 kg/5.
cm (vertical), 14.5 kg/5 cm (horizontal), has the performance of an airflow rate of 42 cc/cm2/sec, and the proportion (weight) of split fibers of 0.5 denier or less is 39.4%,
The surface feathers were relatively inconspicuous and the nonwoven fabric maintained a soft texture, making it suitable for various filters and interior fabrics.

[0020]

[Effects] As explained in detail above, according to the method of the present invention, splitting nonwovens containing homogeneous ultrafine fibers with good process passability can be easily produced by using conventional spinning machines and water jet machines as they are. The obtained nonwoven fabric is excellent in all required physical properties such as strength, texture, and breathability, and has excellent suitability for filters, wipers, artificial leather bases, etc.

Claims (1)

[Claims] Claim 1: After carding splittable composite synthetic fibers to form a web containing splittable fibers, the composite synthetic fibers are split using a water jet and the web is entangled to form a splittable nonwoven fabric. A method for producing a split nonwoven fabric.