JPH0726307B2 - Spunbond nonwoven fabric and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a spunbonded nonwoven fabric and a method for producing the same,
In particular, it is intended to obtain a nonwoven fabric which is flexible in the longitudinal and transverse directions.

[Conventional technology]

Conventionally, non-woven fabrics have been used for various purposes, when using it as a surface sheet of a paper diaper, it is rich in flexibility because it directly touches the soft skin of the baby, and has excellent abrasion resistance, Physical properties such as excellent mechanical strength are required.

The present invention is intended to solve such problems,
It is a fundamental object to provide a method for producing a spunbonded nonwoven fabric which can be made flexible while maintaining abrasion resistance.

[Means for Solving the Problems] In order to solve the above-mentioned technical problems, the present invention arranges the axial line of the filament in the longitudinal direction (which is the same as the flow direction of the filament; A web having a longitudinal maximum tensile load / transverse maximum tensile load of 3.0 or more advances in the longitudinal direction and has wavy wrinkles whose undulations are orthogonal to the surface of the web to give a spunbonded nonwoven fabric.

Then, the manufacturing method is a method of manufacturing a strip-shaped spunbonded non-woven fabric by flowing filaments in a certain direction. This is a method of forming a web having a load / maximum tensile load in the transverse direction) of 3.0 or more, and then subjecting this web to crepe processing to advance in the longitudinal direction so that wavy wrinkles are formed in which the undulations are orthogonal to the surface of the web.

[Action]

If the filament axis is aligned in the direction of its flow (longitudinal), the resulting web will exhibit lateral flexibility. Further, if the warp yarn array coefficient (the maximum tensile load in the flow direction, that is, the longitudinal direction / the maximum tensile load in the transverse direction) is 3.0 or more, the flexibility in the transverse direction becomes necessary and sufficient.

Further, the longitudinal flexibility of the web is hard and soft because the filaments are arranged in the flow direction (longitudinal direction). Therefore, the longitudinal flexibility of the web becomes necessary and sufficient by forming the wavy wrinkles that are formed in the web in the longitudinal direction and the undulations are orthogonal to the surface of the web.

〔Example〕

By the way, non-woven fabric manufacturing methods are roughly divided into a wet method that uses a papermaking method and a dry method that does not, and a dry method is an adhesive type in which filaments are further bonded with an adhesive, and the filaments are mechanically entangled and bonded together. It is divided into a mechanical binding type and a spinning type in which spun filaments are accumulated on the moving and collecting surface by static electricity or air flow.Generally, when producing a nonwoven fabric by these production methods, the filament arrangement is random, A manufacturing method for obtaining a belt-shaped web by flowing in a constant direction, wherein filaments are arranged with their axes oriented in the flow direction.

Then, it is preferable to arrange the filaments in a spunbond method which is a spinning method suitable for arranging the axis lines of the filaments in the flow direction, and the present invention provides a nonwoven fabric formed by the spunbond and a spunbond method. To improve the nonwoven fabric and its manufacturing method.

The spunbond method according to the present invention will be described below with reference to FIGS. 1 and 2. As shown in FIG. 1, molten polymer is spouted from a spinneret 1 in a comb shape to spin a filament 2, and the filament 2 is put on an air flow spouted from an air sucker 3 and accumulated on a moving collection surface 4. At that time, when the filament-shaped filaments are directly received by the moving and collecting surface 4, the filaments 2 can be arranged with the axis lined in the direction of the flow and collected, thereby obtaining the web 5 required for the present invention. You can

In addition, the filament feeding rate, the flow rate on the collecting surface, and the like can be appropriately adjusted by using the method disclosed in JP-B-47-24991.

Here, the meaning of arranging the axis of the filament in the direction of flow means to align the axis of the filament with the direction of flow, but not only when the axis of the filament is parallel to the direction of flow, On the other hand, even if the filaments cross each other at a slight angle, if they are arranged so as to be along the flow direction when viewed as a whole, some variation is allowed.

When the filaments are arranged with the axis line oriented in the flow direction according to the present invention, the warp yarn arrangement coefficient [(longitudinal tensile maximum load / transverse maximum tensile load) when the flow direction is the longitudinal direction is the warp yarn arrangement. Defined as coefficient] is 3.0 or more. The reason for setting the warp yarn arrangement coefficient to 3.0 or more is that when the filaments are arranged in the flow direction in this way, the formed web becomes flexible in the transverse direction, but the necessary and sufficient conditions for the desired flexibility are warp yarns. This is because it is satisfied by setting the array coefficient to 3.0 or more (see FIG. 3).

In order to have flexibility in the longitudinal direction, the web formed as described above may be creped and undulated in the longitudinal direction. Here, the meaning of waviness in the vertical direction is to make the traveling direction of the wave orthogonal to the previously defined vertical direction (flow direction). That is, this wave travels in the longitudinal direction as shown in FIG. 2, and a wavy wrinkle whose undulations are orthogonal to the surface of the web 5 is formed. Then, the crepe process is performed by a known processing means. For example, as shown in FIG. 2, the upper surface of the web 5 delivered by a roll 6 is pressed by a sandpaper-like rough surface plate 7, and the web 5 is rubbed by the friction force. Wavy creases are added in the flow direction of 1, that is, in the vertical direction.

When embossing is applied, embossing calendar treatment may be applied to the web before creping as described above. Even if embossing is applied, the flexibility does not deteriorate if the above treatment is applied.

The raw material filaments that can be used in the present invention are, for example, nylon, polyester, acryl, polypropylene, polyethylene, polystyrene, etc., and if it is desired to impart hydrophilicity to the nonwoven fabric depending on the application, the raw material filaments may be coated with a surfactant. good. Examples of the surfactant to be used include polyoxyethylene alkylphenol type, alkyl sulfate type, aliphatic type, alkyl ethanolamine type and the like.

[Examples and Comparative Examples]

Hereinafter, examples of the nonwoven fabric according to the present invention will be described together with comparative examples.

<Comparative Examples 1 to 4> First, a web in which polypropylene filaments are randomly arranged (Comparative Example 1) by a spunbond method, and a warp yarn arrangement coefficient of 2.5 in which the axis of the polypropylene filaments is also oriented in the flow direction (longitudinal direction). , 3.4, and 6.2 webs (Comparative Examples 2 to 4) were molded, and various physical properties were measured. The longitudinal flexibility and the lateral flexibility were measured by the handle odometer method.

The results are shown in Table 1. As is clear from this table, when the filament axis is aligned in the longitudinal direction, the web having a warp orientation coefficient of 3 or more has a numerical value of 2.0 and 1.6, respectively, as compared with the randomly arranged web as in Comparative Example 1. Therefore, it is understood that the lateral flexibility is good. However, the numerical values for vertical flexibility are 6.5 and 6.9, respectively, and are rather stiffer than those arranged randomly.

<Comparative Examples 5 to 6> The webs of Comparative Examples 1 and 2 were subjected to crepe processing, and wavy wrinkles advancing in the longitudinal direction and orthogonal to the planes of the webs were made to be Comparative Examples 5 and 6, and various physical properties were measured. did.

The results are shown in Table 2. As is clear from this table, even if a web having a warp arrangement coefficient of less than 3 is randomly arranged, the nonwoven fabric having excellent flexibility in both the longitudinal and transverse directions cannot be obtained.

<Examples 1 and 2> The webs of Comparative Examples 3 and 4 were subjected to crepe processing, and progressed in the longitudinal direction to obtain wavy wrinkled nonwoven fabrics, and various physical properties were measured.

The results are shown in Table 2. As is clear from this table, a web having a warp yarn array coefficient of 3 or more is creped, and wavy wrinkles that progress in the longitudinal direction and the undulations are orthogonal to the surface of the web are obtained. It turns out that it is excellent.

<Example 3> Polypropylene filaments are arranged in the machine direction by a spun bond method to form a web having a warp arrangement coefficient of 3.4.
Even if a 2.5% aqueous solution of a polyoxyethylene alkylphenol type surfactant is applied to this web in advance at a rate of 4 ml / m ² , the flexibility is hardly changed.

〔The invention's effect〕

According to the present invention, by arranging the axis lines of the filaments in the longitudinal direction, the warp arrangement coefficient is 3.0 or more to give flexibility in the transverse direction, and the longitudinal direction of the web is advanced,
Since the undulations have wavy wrinkles that are orthogonal to the surface of the web to give it flexibility in the longitudinal direction, it can be made into a very flexible nonwoven fabric, and the flexibility can be maintained even after embossing. It is possible to obtain a flexible non-woven fabric having frictional force.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of an apparatus for producing the nonwoven fabric of the present invention, FIG. 2 is a sectional view showing an example of a crepe processing machine, and FIG. 3 shows the relationship between the warp yarn array coefficient and the lateral flexibility. It is a graph figure. 1 ... Spinneret 2 ... Filament 3 ... Air sucker 4 ... Moving collection. 5: Web 6: Roll 7: Rough surface plate

Claims (2)

[Claims] 1. A web having a warp arrangement coefficient (longitudinal maximum tensile load / horizontal maximum tensile load) of 3.0 or more formed by arranging filament axes in the longitudinal direction and advancing in the longitudinal direction. , A spunbonded non-woven fabric characterized in that the undulations are formed with wavy wrinkles orthogonal to the surface of the web. 2. A method for producing a spunbonded nonwoven fabric having a good resistance by flowing filaments in a certain direction, wherein the filament axis is aligned in the direction of flow, and the warp array coefficient (the maximum tensile load in the machine direction, that is, the longitudinal direction). After forming a web having a maximum tensile load in the transverse direction of 3.0 or more), the web is creped to proceed in the longitudinal direction, and waviness wrinkles that are orthogonal to the surface of the web. For producing spunbonded nonwoven fabric.