JPH0663166B2 - Nonwoven manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Purpose of the invention [Industrial field of application] The present invention introduces a fibrous web onto a support and jets a high-speed water stream onto the fibrous web to entangle the fibers to form a nonwoven fabric. To a method of manufacturing.

[Conventional technology]

Conventionally, the following is known as a method and an apparatus for producing the non-woven fabric.

A method and apparatus for conducting a fiber entanglement treatment by guiding a fiber web onto a rotating endless mesh screen and ejecting a high-speed water stream from a large number of fine orifices onto the fiber web while draining through the mesh of the screen. These are shown, for example, in US Pat. No. 3,449,809.

The fibrous web is guided onto an impermeable endless belt that rotates, and the fiber web is preliminarily entangled by injecting a high-speed water stream from a large number of fine orifices into the fibrous web, and then the fibrous web is downstream of the belt. A method and a device for carrying out a multi-stage and full-scale fiber entanglement treatment by introducing the fibers onto a water-impermeable roll arranged at a predetermined interval and injecting a high-speed water stream onto the fiber web on each roll. They are,
For example, it is disclosed in the applicant's British Patent No. 2,085,493B (Patent Family JP-A-57-39268).

Guide on a support consisting of a combination of an endless mesh screen rotating a fibrous web and an impermeable member having a narrow support surface in contact with the lower surface of the screen, while suctioning and draining from the periphery of the member, The fiber web is preliminarily entangled by jetting a high-speed water stream onto the fiber web from a large number of fine orifices on the member, and then the fiber web is placed downstream of the screen at predetermined intervals. A method and an apparatus for performing a multi-step and full-scale fiber entanglement treatment by guiding the fibers onto a water-permeable roll and jetting a high-speed water stream from a large number of fine orifices onto the fiber web on each roll. These are disclosed in, for example, European Patent Publication No. 0,147,904, A2 of the present applicant (Patent Family Japanese Patent Publication No. 62-57723).

[Problems to be solved by the invention]

In the above-mentioned technique, in order to produce a non-porous non-woven fabric, since water jetting is usually carried out while supporting the fiber web with a relatively long continuous mesh screen having an open area of 30 to 70%, The jet water flow after the fiber entanglement treatment is relatively well drained through the mesh, and there is the advantage that there is no draft that disturbs the fiber orientation on the fiber web, but on the other hand, the jet water flow passes through the screen and The repulsive flow caused by the collision of the jet water is weak and weak, and the energy of the repulsive flow hardly contributes to the fiber entanglement, so the fiber entanglement efficiency is low, and a nonwoven fabric having high fiber entanglement strength is obtained. I can't. Furthermore, since the fibers of the fibrous web are entangled with the yarn intersections that compose the screen by the water jet, the fibers are cut and remain on the screen when the fiber web is peeled from the screen and become clogged. This clogging becomes more remarkable when the water jet pressure and the jet amount are increased in order to improve the fiber entanglement efficiency and the fiber entanglement strength. Therefore, in order to obtain a non-woven fabric having a high fiber entanglement strength, not only the frequency of replacing the screen becomes high, but also a high water jet pressure and a large amount of water are required,
Moreover, low productivity is unavoidable and very uneconomical.

From an ideal point of view, the above-mentioned technique does not allow the jet water flow to pass through the belt, so that the energy of the jet water flow colliding with the belt and the repulsive flow energy can be fully utilized, and thus the drawbacks of the above technique It is possible to improve the fiber entanglement efficiency and the fiber entanglement strength. However, from a practical point of view, since the fiber entanglement treatment is performed on the starting fiber web (the upper web formed by the card etc.) where the fiber entanglement is extremely low and fluffed on the belt where the jet water flow does not permeate. Since the fibers floating in the water flow on the belt afterwards tends to impair the processing stability of the fiber entanglement due to the blowing up of the fibers by the repulsive flow,
There is no choice but to lower the water jet pressure. If it is so low, the fiber entanglement strength cannot be sufficiently increased, and therefore, when the fiber web is transferred between the rolls in the next step, the fiber web is drafted more than necessary in the machine direction and the fibers are moved in the same direction. Orientation is generated and formation is disturbed.

The above-mentioned technique aims to fully utilize the jet flow and the repulsive flow that collide with the impermeable member, as in the above-mentioned technique. The clogging cannot be cleared. In addition, although the stability of the fiber entanglement treatment, which is a drawback of the above-mentioned technique, can be improved to some extent, the drawback cannot be solved sufficiently. Therefore, when the fibrous web is peeled from the screen and transferred between the rolls, the fibrous web is drafted in the machine direction more than necessary, like the drawback of the above technique, and the fibers in the same direction are draped. Orientation occurs.

An object of the present invention is to use a cylinder having a drainage hole as a support in a preliminary step to enhance the fiber entanglement efficiency by fully utilizing the energy of a jet water flow and its repulsive flow, thereby supporting the support in the preliminary step. Eliminates the difficulty of peeling due to the entanglement of fibers when using a screen as well as eliminates the fiber orientation in the machine direction during the transfer process of the fiber web, thus without disturbing the formation of the fiber web into a full-scale process. It is an object of the present invention to provide a method for producing an excellent non-woven fabric having a fiber entanglement strength and a uniform fiber redistribution, which is transported.

(2) Configuration of the Invention [Means for Solving the Problems] In the present invention, a fibrous web is guided onto a first support, and the fibrous web on the first support is traversed at predetermined intervals. A step of preliminarily randomly entangling the fibers of the fibrous web by a jet of water from a plurality of orifices arranged in a row, and a plurality of the fibrous webs arranged at predetermined intervals in the moving direction of the fibrous web. To the impermeable second support, and the fibers of the fibrous web are ejected by a jet of water from a plurality of orifices arranged at predetermined intervals in a direction traversing the fibrous web on the second support. In the method for producing a non-woven fabric, which comprises a step of randomly entangling in full scale, a cylinder in which a large number of drainage holes having a diameter of 0.2 to 1.0 mm are regularly arranged on a smooth peripheral surface as the first support. To use Characterize.

[Embodiment]

1 and 2 show a cylinder support 1 for use in the present invention. The support 1 is a plate having a smooth surface and is formed into a cylinder having a predetermined diameter and length. A large number of independent drain holes 2 are provided on the plate surface of the support 1 at predetermined intervals. As shown by the chain line in FIG. 4, the drainage holes 2 are arranged so that four holes adjacent to each other form a diamond pattern in the circumferential direction of the cylinder (movement of the fiber web described later) indicated by the arrow. This is because it has the effect of randomizing the fibers to some extent in the process of moving the fiber web on the support 1. The drainage hole 2 has a diameter of 0.2 to 1.0 mm,
The area ratio of the support 1 to the effective plate surface is preferably 2.5 to 30%. If the diameter is 0.2 mm or less, the pores are clogged with impurities contained in the fiber web or the jet water flow, as a result, the drainage effect is reduced, while if the diameter is 1.0 mm or more, the fibers of the fiber web are jetted. The pressure of the water stream may cause the webs to agglomerate or pass through the pores, disturbing the fiber alignment of the web, and forming undesired openings in the manufactured nonwoven fabric. The area ratio is 2.5%
If it is below, there is no drainage effect. On the other hand, if the area ratio is 30% or more, the plate surface that causes the jet water flow to collide with the support 1 to generate a repulsive flow decreases, and the mechanical strength of the support 1 decreases. To do.

The support 1 is supported by a support roll 3. The support roll 3 is provided with a large number of protrusions 4 having a triangular cross-section and extending in the roll axial direction at predetermined intervals in the circumferential direction, and a large number of drainage holes 5 at predetermined intervals between the protrusions 4. The support roll 3 is inserted and fixed in the support body 1 in a state where the tops of the protrusions 4 are in contact with the inner surface of the support body 1. Although not shown, a drainage suction means is installed in the support roll 3.

The support 1 is formed of a metal plate having a hardness that causes a repulsive flow when the jet water flow collides with the support 1 and can contribute to the fiber entanglement again.

FIG. 3 shows an embodiment in which the support 1 is arranged in a nonwoven fabric manufacturing apparatus.

This apparatus comprises a support 1, a belt conveyor 6, a water film supply means 7, and respective jetting means 8 arranged on the support 1 so as to face each other.
A belt conveyer 9, each impermeable support roll 10 arranged at a predetermined interval in the machine direction downstream of the support 1, each jetting means 11 provided on the impermeable support roll 10, and a pair of squeezing rolls. Including 12 and.

The water film supply means 7 is provided for constantly supplying a fixed amount of water flow from the tank 13 and causing it to flow down through the inclined plate 14 to form a water film and supply the fibrous web 15. Thereby, the fiber entanglement treatment can be effectively performed while suppressing the fluffing of the fibers of the fiber web 15 and stabilizing the morphology.

Each of the jetting means 8 and 11 is arranged across the fibrous web 15 in the width direction thereof, and has orifices of fine diameter arranged in the transverse direction at a predetermined interval.

Each support 10 is formed of metal or the like having a hardness that can contribute to fiber entanglement when the jet water flow collides with it.

In an embodiment using such a device, the fiber web 15 is guided onto the support 1, and while being drained by the suction means inside the support 1, the fibers are preliminarily randomly entangled by the water jet from the jetting means 8, Furthermore, the fiber web 15 is guided onto each support 10, and the fibers are randomly entangled on the respective supports by the water jet from each jetting means 11 to complete the treatment step, and the non-porous nonwoven fabric is obtained. Are to be manufactured.

Preferably the back pressure of the water jet streams are 20 and 100 kg / cm ^2, when is 20 kg / cm ² or less, not be example only energy capable of entangling the fibers, tenacity insufficient fiber entanglement efficiency and confounding However, if it is 100 kg / cm ² or more, the cost increases and it is disadvantageous commercially. Also, the amount of water sprayed is 0.5 to 20.
/ M ² · sec is preferable, 0.5 / m ² · se
If it is c or less, the fiber entanglement efficiency and the entanglement strength are insufficient as described above. The amount of water is determined by the injection pressure and the diameter and number of orifices arranged in a row in the water flow injection means.
Even if it is m ² · sec or more, the fiber entanglement efficiency and the entanglement strength are not improved in proportion to the amount of water, which is economically disadvantageous.

As the fibrous web, all conventionally known non-woven fabric fibers can be used, and the web form may be parallel, random or the like, but the basis weight is 100 g / m ² or less. preferable.

Example 1 A fiber web made of 1.4 d × 44 mm polyester fiber was introduced onto the apertured support shown in FIG. 1 used in the manufacturing process shown in FIG. 3, and the fiber was sucked and drained from the back side of the support. A high-speed water stream was jetted from the top of the web to obtain a nonwoven fabric having a basis weight of 30 g / m ₂ and having substantially no pores (no pattern). Then, the tensile strength of the non-woven fabric obtained by changing the jet pressure with the amount of water jetted to the fiber web being 1 / m ² · sec was measured,
The relationship with the tensile strength is shown in FIG.

The support was made of nickel in the form of a flat plate, and its specifications are as shown in FIG. 4, and the porosity was 9.5%.

Comparative Example 1 A nonwoven fabric having a basis weight of 30 g / m ² and substantially no openings (no pattern) was used under the same conditions as in Example 1 except that a polyester mesh screen (satin weave, 76 mesh) was used as the support. Obtained. Then, the same measurement as in Example 1 was performed, and the result is shown in FIG.

Example 2, Comparative Example 2 By fixing the injection pressure to 50 kg / cm ² , a non-perforated (non-patterned) non-woven fabric was obtained under the same conditions as in Example 1 and Comparative Example 1.
The relationship between the jetted water amount per 1 m ² and the MD tensile strength of the nonwoven fabric was measured, and the results are shown in FIG.

Evaluation of Examples 1 and 2 and Comparative Examples 1 and 2 In Examples 1 and 2, the fiber entanglement efficiency is remarkably high in terms of the amount of water injected and the pressure as compared with the conventional support made of mesh screen. Therefore, according to Examples 1 and 2,
In order to obtain a nonwoven fabric having the same strength as the conventional method using a mesh screen as a support, a small amount of water is used and low pressure is required, which is very advantageous in terms of running cost and equipment. In other words, if the costs are the same, it is possible to obtain a material having excellent strength and physical properties.

Example 3 1.4 g × 44 mm polyester fiber having a basis weight of 30 g / m ²
The fibrous web of Fig. 3 was introduced onto the open hole support (opening rate 9.5%) shown in Fig. 1 used in the manufacturing process shown in Fig. 3, and the fibrous web was pressurized to 50 kg while suctioning and draining from the back side of the support. /cm
MD tensile strength of 20g / cm // g / m, which can be processed by high-speed water flow of ² and can be processed by high-speed water flow on impermeable roll.
A fiber entangled web of ² was obtained. The amount of treated water required during this period is
It was 1.5 / m ² · sec.

Then, 2 Fast water pressure 50 kg / cm ² of said fibrous web on impermeable roll stainless steel having a diameter of 140mm
After repeated treatment, a nonwoven fabric having MD tensile strength of 83 g / cm // g / m ² and uniform fiber rearrangement and substantially no pores (no pattern) was obtained.

The total amount of treated water is 5.8 with respect to the fiber web (nonwoven fabric).
/ M ² · sec.

The relationship between the MD tensile strength of the obtained non-woven fabric and the amount of treated water is described in Section 7.
As shown in the figure.

Comparative Example 3-1 The same fiber web as in Example 3 was introduced onto a polyester mesh screen (76 mesh), and the fiber web was treated three times with a high-speed water stream at a pressure of 50 kg / cm ² , and the MD tensile strength was 20 g. A fiber entangled web of / cm // g / cm ² was obtained. The amount of treated water required during this period was 7 / m ^{2 with} respect to the fiber web 7.
・ It was sec.

Then, the fiber web was treated under the same conditions as in Example 3,
Virtually no holes (no pattern) with almost the same MD tensile strength
A non-woven fabric was obtained.

The total amount of treated water is 11.4 with respect to the fiber web (nonwoven fabric).
/ M ² · sec.

The relationship between the tensile strength of the obtained nonwoven fabric and the amount of treated water is shown in FIG.

Comparative Example 3-2 The same fiber web as in Example 3 was introduced onto a polyester mesh screen (76 mesh), and the fiber web was treated 5 times with a high-speed water stream at a pressure of 30 kg / cm ² , and the MD tensile strength was 20 g. A fiber entangled web of / cm // g / m ² was obtained. The amount of treated water required during this period was 10.5 / m ^{2 with} respect to the fiber web.
・ It was sec.

Then, the fiber web was treated under the same conditions as in Example 3,
Virtually no holes (no pattern) with almost the same MD tensile strength
A non-woven fabric was obtained.

The total amount of treated water is 15 / for the fiber web (nonwoven fabric).
It was m ² · sec.

The relationship between the tensile strength of the obtained nonwoven fabric and the amount of treated water is shown in FIG.

Evaluation of Example 3 and Comparative Examples 3-1 and 3-2 Even when the fiber web is entangled with fibers on an apertured support, and then the fibers are entangled again on a support made of a water-impermeable roll, the conventional practice is carried out. The fiber entanglement efficiency is higher than the method in which the fibers are entangled with a support made of a mesh screen and then the fibers are entangled again with a support made of an impermeable roll, and it is advantageous in terms of strength physical properties and economy.

(3) Effects of the Invention According to the method of the present invention, as is clear from the above,
As a preliminary step, the advantage of using a water-impermeable or non-porous support is that the jet flow and the repulsive flow resulting from its impact on the support can be fully utilized as energy for the fiber entanglement process. In addition to having advantages, the disadvantage of using impermeable or non-porous support is that the fiber entanglement is caused by the fact that the jet pressure of the water stream cannot be increased and the jetting amount cannot be increased due to insufficient drainage. It is possible to solve the drawback that the efficiency and the confounding strength cannot be increased. Further, in the preliminary step, there is a disadvantage due to the use of the mesh screen as the support, that is, the fibers are entangled at the intersections of the yarns forming the mesh screen, and the fiber web (nonwoven fabric) is peeled from the support. At that time, a draft is applied more than necessary to cause fiber orientation in the machine direction, disturbing the rearrangement of the fibers, and further, since the fibers are cut and the support is clogged, it is necessary to frequently replace the support. A certain disadvantage can be eliminated.

In particular, in the preliminary step, since the cylinder that is the support having the above characteristics is used, the required strength is given so that the formation is not disturbed in the process of passing the fiber web to the roll that is the support in the full-scale step. As a result, the texture of the non-woven fabric obtained by entangling the fibers in the full-scale process can be improved.

[Brief description of drawings]

FIG. 1 is a separation perspective view of a cylinder having a drainage hole, which is a first support in the present invention, and a roll supporting the cylinder and having a drainage hole. FIG. 2 is a partial cross-sectional view of the combined state of the both. FIG. 3 is a schematic side view showing an embodiment of a manufacturing apparatus in which the support is arranged. FIG. 4 is a partial plan view and a sectional view of the first support used in the example. FIG. 5 is a graph showing the relationship between MD tensile strength and injection pressure in Example 1 and Comparative Example 1. FIG. 6 is a graph showing the relationship between MD tensile strength and water content in Example 2 and Comparative Example 2. FIG. 7 is a graph showing the relationship between MD tensile strength and water content in Example 3 and Comparative Examples 3-1 and 3-2. 1 …… Cylinder 2 …… Drainage hole 8,11 …… Injection means 10 …… Impermeable roll

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-59-125954 (JP, A) JP-A-53-14874 (JP, A) JP-A-54-101984 (JP, A) JP-A-59- 211667 (JP, A) JP 59-45777 (JP, B2) JP 5-55621 (JP, B2)

Claims (1)

[Claims] 1. A fibrous web is guided onto a first support, and the fibrous web is jetted from a plurality of orifices arranged at predetermined intervals in a direction traversing the fibrous web on the first support. The step of preliminarily randomly entangling the fibers, and guiding the fiber web onto a water-impermeable second support consisting of a plurality of rolls arranged at predetermined intervals in the moving direction of the fiber web, A method for producing a non-woven fabric, comprising the steps of full-scale random entanglement of fibers of the fibrous web with a jet of water from a plurality of orifices arranged at predetermined intervals in a direction traversing the fibrous web on a second support. In the above-mentioned manufacturing method, a cylinder having a diameter of 0.2 to 1.0 mm and a large number of drain holes regularly arranged on a smooth peripheral surface is used as the first support.