JP2790357B2 - Air gun for nonwoven fabric production - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air gun for producing a nonwoven fabric, and in particular, to take up a filament spun from a spinning nozzle at a high speed and put it on an air flow to collect a surface such as a screen belt. The present invention relates to a type in which the nonwoven fabric is sent out to form a nonwoven fabric.

[Conventional technology]

2. Description of the Related Art Conventionally, an air gun for producing a nonwoven fabric, particularly an air gun for drawing and drawing filaments spun from a spinning nozzle at a high speed and sending it on a screen belt with an air stream to form a nonwoven fabric (web), for example, has an inner diameter of 6.6. An accelerating tube with a diameter of 280 mm and a diameter of 280 mm is attached to the tip of the air nozzle that sends out the filament.

In this method, a spun filament is drawn from a spinning nozzle and is sent out onto a screen belt in an air stream to form a nonwoven fabric. The filament sent out from the spinning nozzle is first received at an inlet of the air nozzle. A compressed air inlet is provided on a side surface of the air nozzle, and the compressed air supplied from the air nozzle sends out the filament in the air outlet direction.

An accelerating tube is connected to the filament delivery direction of the air nozzle, and the filament guided by air is conveyed through the filament.

A guide tube is provided at the tip of the acceleration tube. This guide tube is for guiding the filament sent out together with the compressed air from the acceleration tube to the separator nozzle. Since the filaments are appropriately dispersed by the separator nozzle and are deposited on the screen belt, the nonwoven fabric is formed by moving the screen belt.

[Problems to be solved by the invention]

By the way, when manufacturing a nonwoven fabric by such a spunbond method, it is required to make the filament fibers thin in order to improve productivity and quality.

Therefore, conventionally, a method of increasing the air pressure supplied to the air nozzle to increase the air flow rate and pulling the fiber strongly. A method of shortening the distance (spinning distance) from the spinning nozzle to the air nozzle, a method of reducing a discharge amount per one of a large number of formed spinning nozzles, a method of increasing the spinning temperature, and the like have been adopted. When productivity is the main focus, the above method and the above method are general.

However, in the method, the filaments are disturbed when the filaments are discharged from the separator nozzle due to the increase in the air flow rate, and the shape of the nonwoven fabric deposited on the screen belt varies, and the uniformity of the nonwoven fabric is reduced. There is a problem of worsening. Further, an increase in the air flow rate causes an increase in running cost, which is a factor of high cost. On the other hand, the latter method has problems from the viewpoint of stable spinning and is difficult to implement.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides an air gun for producing a non-woven fabric capable of stably spinning finely, producing a non-woven fabric of a uniform shape, and preventing running costs from increasing. This is a technical issue.

[Means for solving the problem]

In order to solve the above technical problem, the present invention relates to an air gun for producing a non-woven fabric for forming a non-woven fabric by sending a filament 2 spun from a spinning nozzle 1 onto an air collecting surface with an air stream as follows. Configuration.

It has a filament inlet 9a for receiving the filament 2 sent from the spinning nozzle 1, a filament outlet 9e for sending the filament 2 introduced from the filament inlet 9a, and a compressed air inlet 11 and a compressed air outlet 10b. The compressed air outlet 10b is located around the filament outlet 9e, and the compressed air outlet 10b
Air nozzle 3 that pulls out the filament 2 from the filament outlet 9e by blowing out compressed air from the
An accelerating tube 4 connected to the air nozzle 3 in the direction in which the filament 2 is delivered and guiding and delivering the filament 2
And the ratio of the inner diameter and the length of the accelerating tube 4 is 1:20 to 1:
Set between 250.

[Action]

The spinning is carried out using a molten synthetic resin, which is preferably extruded from a number of spinning nozzles 1 arranged in one or many rows. The spun filaments 2 are usually in a straight line and are spaced apart from each other.

Examples of the synthetic resin to be spun include polyolefins such as polyethylene and polypropylene; or ethylene-vinyl compound copolymers such as ethylene-vinyl chloride copolymer;
Styrene resins; polyvinyl chloride resins such as polyvinyl chloride and polyvinylidene chloride; polyacrylates; polyamides; polyesters such as polyethylene terephthalate; and other synthetic resins as long as they can be spun. These may be used alone or as a mixture. An appropriate amount of an inorganic pigment or an organic pigment may be blended in the synthetic resin.

In general, a plurality of air nozzles 3 for taking out a bundle of spun filaments 2 and sending them out to a screen belt 6 are arranged side by side in order to form a nonwoven fabric having a practical width. In general, the arrangement of a number of air nozzles 3 is set such that the desired overlap of the trajectories of the filaments 2 delivered from the air nozzles 3 over the entire width of the screen belt 6 occurs. The spun filaments 2 are drawn, drawn, dispersed, and sent out by being pulled by an air stream, and are deposited in a complicated manner on the screen belt 6. It is desirable that the inner surface of the accelerating tube 4 is as smooth as possible to reduce the air resistance.

Further, the ratio between the inner diameter and the length of the acceleration tube 4 is 1:20 to 1: 250,
Desirably, 1:50 to 1: 100 is suitable.

As a result, a thinner filament 2 can be obtained with the same air pressure as the conventional one, but if it is desired to obtain a filament 2 of the same thickness as the conventional one, the compressed air at a lower pressure can be used, thereby improving the economic efficiency. Can be done.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 1, the air gun for producing nonwoven fabric of this embodiment includes an air nozzle 3 for drawing a filament 2 spun from a spinneret 1 which is an aggregate of a spinning nozzle, an acceleration tube 4 connected to the air nozzle 3, This accelerator tube 4
And a guide tube 5 connected to the distal end of the guide tube.
At the tip of the guide tube 5, the filament 2 delivered together with the compressed air is screen belt 6.
A separator nozzle (not shown) that diffuses toward the nozzle is connected. The filaments dispersed by the separator nozzle are deposited on the screen belt 6 to form a nonwoven web.

The spinneret 1, which is an assembly of spinning nozzles, has nine small holes each having 108 small holes each having a diameter of 0.85 mm, and spins the molten resin extruded from the extruder 1a.

As shown in FIG. 2, the air nozzle 3 includes a first nozzle 9 and a second nozzle 10 connected to the first nozzle 9.

The first nozzle 9 has a filament inlet 9a for receiving the filament 2 sent from the spinneret 1, and an interior continuous with the filament inlet 9a has a tapered conduit 9b whose diameter is reduced partway toward the tip. There is a straight pipe 9c that travels with the same inner diameter from the tip of the tapered pipe 9b to the filament outlet 9e. This straight pipe 9c is a nozzle pipe 9d
And is in a protruding state.

So as to surround the tip of the nozzle tube 9,
The second nozzle 10 is connected to the first nozzle 9. The second nozzle 10 has an outlet nozzle 10a surrounding the tip of the nozzle tube 9d. A slight clearance is formed between the inner surface of the outlet nozzle 10a and the outer surface of the nozzle tube 9d, which forms a compressed air outlet 10b around the filament outlet 9e at the tip of the nozzle tube 9d. Then, the inner surface of the outlet nozzle 10a is gradually reduced in diameter from the air inlet 10c side, and when the diameter exceeds the maximum constricted portion 10d in the middle, the diameter is gradually increased, and thereafter the same diameter is obtained from a portion corresponding to the filament outlet 9e. It will be a straight conduit going up to.

On the other hand, a compressed air inlet 11 is provided on the side surface of the second nozzle 10, and this compressed air inlet 11 communicates with the air port 10c of the outlet nozzle 10a. The air introduced from the compressed air inlet 11 to the outlet nozzle 10a has a maximum flow velocity when passing through the maximum constricted portion 10d, whereby the air is strongly ejected from the compressed air outlet 10b in the direction of arrow F. Thus, the filament 2 passing near the center of the nozzle tube 9d is strongly pulled out.

An accelerating tube 4 for guiding the filament 2 is connected to the second nozzle 10 in a direction in which the filament 2 is delivered, and a guide tube 5 is connected to a tip of the accelerating tube 4. The guide tube 5 guides the filament 2 to the separator nozzle, and the tip of the guide tube 5 is connected to the separator nozzle.

This separator nozzle applies the filament 2 delivered from the acceleration tube 4 together with the compressed air to the screen belt 6.
It is for spreading to.

The inner diameter of the acceleration tube 4 is represented by D, and the length is represented by L.

<First Embodiment> The filament 2 is radiated to the screen belt 6 by the air gun for manufacturing a nonwoven fabric having the above-described configuration.
Observation and measurement of the fineness of the nonwoven fabric constituent fibers deposited thereon yielded the results shown in FIG.

Here, the material of the filament 2 is polypropylene, the discharge amount is 42 kg / H, and the pressure of the air supplied to the air nozzle 3 is
9 kg / cmG, the inner diameter (D) of the acceleration tube 4 was changed to 7.0 mm, and the length (L) was changed to 280 mm, 450 mm, and 600 mm.

As is apparent from the results shown in FIG.
When the diameter was 450 mm or more, the fineness of the filament 2 could be 1.8 denier or less. At this time, the ratio between the inner diameter (D) and the length (L) of the acceleration tube 4 was 1:64.

<Second embodiment> Next, the material of the filament 2 was polypropylene, the discharge amount was 42 kg / H, the diameter of the small hole of the spinneret was 0.85 mm, and seven sets each including 130 sections were provided. .
The spinning distance (the distance from the spinning nozzle to the air nozzle) was 4.5 m.

When the effect of the shape of the accelerating tube 4 on the fineness of the filament 2 was tested under these conditions, the results shown in FIG. 4 were obtained.
That is, when the diameter of the accelerating tube 4 is 6.6 mm and its length is 280 mm (the graph shown by − in FIG. 4), the air nozzle 3
Even when a pressure of 8 kg / cmG is applied, the fineness of filament 2 is
Although it can only be about 2.4 denier, the diameter of the acceleration tube 4
If the length is set to 7.0 mm and the length is set to 600 mm (the graph shown by □-□ in FIG. 4), the filament 2 can be thinned to about 1.8 denier even when the same pressure of 8 kg / cmG as in the previous example is applied. Was.

<Third embodiment> Regarding the relationship between the case where the guide tube 5 having an inner diameter of 10 mmφ is connected to the acceleration tube 4 and the case where the guide tube 5 is not connected, the relationship between the change in the length of the acceleration tube and the yarn tension (tension applied to the filament) Observed.

The results are shown in the graph of FIG. In FIG. 5, the graph indicated by ○ -− indicates the case where only the acceleration tube 4 is connected, and the graph indicated by □-□ indicates the case where the guide tube 5 is connected to the acceleration tube 4. As is clear from this result, it was found that the longer the length of the accelerating tube 4, the higher the yarn tension. In addition, it can be seen that, when the guide tube 5 is attached, the traction ability is further increased as compared with the case where only the acceleration tube 4 is used.

〔The invention's effect〕

According to the present invention, the diameter of the filament can be reduced without increasing the air pressure supplied to the air nozzle.
Therefore, a nonwoven fabric having a good dispersion and a uniform shape can be produced. In addition, since the air pressure can be the same as in the conventional case, the running cost does not increase and the operation can be performed at low cost.

[Brief description of the drawings]

1 to 5 show an embodiment of the present invention, FIG. 1 is a schematic view of the entire apparatus, FIG. 2 is an enlarged sectional view thereof, and FIG. 3 is a relationship between the accelerating tube length and fineness of the first embodiment. , FIG. 4 is a graph of the second embodiment, a graph showing the relationship between air pressure and fineness when the acceleration tube is changed, and FIG. 5 is a graph of the third embodiment. FIG. 4 is a graph showing the relationship between the length of the accelerating tube and the yarn tension depending on the presence or absence of a guide tube. 1 Spinneret with spinning nozzle 2 Filament 3 Air nozzle 4 Accelerator tube 5 Guide tube 6 Screen belt as collecting surface 9a Filament inlet 9e Filament outlet 10b Compressed air outlet 11… Compressed air inlet

Claims (2)

(57) [Claims] An air gun for manufacturing a nonwoven fabric for forming a nonwoven fabric by sending a filament spun from a spinning nozzle onto an air flow on an air flow, wherein the inlet receives the filament sent from the spinning nozzle. And an outlet for delivering the filament introduced from the inlet, and a compressed air inlet and a compressed air outlet. The compressed air outlet is located around the filament outlet, and a compressed air outlet is provided. An air nozzle that pulls out the filament from the filament outlet by blowing out compressed air from the air nozzle, and is connected in the filament sending direction of the air nozzle,
An acceleration tube for guiding and sending out the filament, comprising: a ratio of the inner diameter to the length of the acceleration tube of 1:20 to 1: 250.
An air gun for producing nonwoven fabrics, wherein the air gun is set between the two. 2. A guide tube is connected to a tip of the acceleration tube, and a ratio of an inner diameter to a length of the guide tube is 1:50.
The air gun for producing a nonwoven fabric according to claim 1, wherein the air gun is set between 1 and 300.