JPH0524260B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing a nonwoven fabric, and particularly to an improvement in a method for producing a nonwoven fabric by waterjet bonding.

(Prior art) When manufacturing nonwoven fabrics, there are various methods such as chemical bonding (resin processing), needle punching, thermal bonding, static bonding, and waterjet bonding (spunlace method), depending on the method of intertwining the constituent fibers. is publicly known.

Among these methods, the method using waterjet bonding is a method in which a fiber web is run and a waterjet is sprayed onto the web during the run to entangle the fibers that make up the web, and the processing speed is faster than other methods. Recently, attempts have been made to put it into practical use because it has advantages such as a relatively large diameter and little damage to the fibers.

(Problem to be Solved by the Invention) However, the method of spraying water jet described above naturally requires a large amount of water, and if the water is to be reused, water treatment equipment is required. When using a water jet, there was a problem in that impurities contained in the water often clogged the nozzle, causing nozzle clogging.

The present invention addresses the above-mentioned circumstances, and in particular separates the water application from the air jet, thereby eliminating the need for the water treatment equipment and saving energy, as well as preventing clogging of the jet nozzle and preventing fibers from becoming entangled with each other. The purpose is to strengthen the

(Means for Solving the Problem) That is, the feature of the present invention that satisfies the above object is that a nonwoven fabric is manufactured by running a fiber web and intertwining the fibers constituting the web with each other during the run. , adding moisture to the fiber web in an amount of 50 to 100% by weight of the fibers;
The purpose is to cause the fibers to run in a state in which they are contained, and to blow a jet of air from a nozzle onto the fibers, thereby entangling the fibers with each other.

The fibers that make up the fiber web are natural fibers,
It can be any fiber such as synthetic fiber, preferably short fiber.

These fiber webs are made through a normal web making process, and the required basis weight is appropriately selected. Of course, it is also possible to use low melting point synthetic fibers.

Then, during the process of manufacturing a nonwoven fabric, moisture is added to the fibrous web in the web state, and thereafter, the fiber web is exposed to an air stream ejected from a nozzle. In this case, the moisture content is 50% of the fiber weight.
Approximately 100% by weight is preferable; if it is less than 50% by weight, it will be dry or slightly humid and the effectiveness of water use will be poor; on the other hand, if it exceeds 100% by weight,
Water will fall and wet the surrounding area.

Therefore, the amount is preferably about 50 to 100% by weight, and in this state the effect of water, which will be described later, is effectively exerted. In addition, the jetted air flow may be one whose pressure and momentum directly act on the fibers and give energy to the existing free water, and usually air at room temperature is sufficient.
Warmed air can also be used. Particularly in the case of a fiber web containing low melting point fibers, it is advantageous to fix the entangled state by partially melting the fibers.

(Function) As described above, the present invention is a method of pre-containing a predetermined amount of water in a fiber web, and then blowing a jet of air onto the fiber web to entangle it. At the same time, the surface tension of the water temporarily gives the fibers a cohesive property, and the wind pressure and momentum of the air give momentum to the water between the fibers, which promotes the mutual entanglement of the fibers.

On the other hand, by blowing an air stream, there is no need for reuse equipment like water as a medium for kinetic energy and pressure, and it also directly increases the intertwining of fibers with air pressure and momentum, and indirectly gives energy to free water and further strengthens the entanglement.

(Example) Hereinafter, specific embodiments of the present invention will be described with further reference to the accompanying drawings.

Fig. 1 shows an outline of the process of manufacturing a nonwoven fabric according to the present invention. In the figure, the raw short fibers undergo card preparation work in a mixed cotton opening device 1, and then are sent to the next card 2 to form uniform fibers. It is formed as a web W. Although not shown, this fiber web is processed by a crosslay device and a drafter, which adjust the fiber orientation and the basis weight. It is sent to an applicator and the required moisture is applied.

In this case, the moisture content is 25% of the fiber weight.
If it is less than 50%, the effect will be poor in a dry state, and if it is less than 25-50%, it will only be in a moist state, so it is preferable to apply 50% or more, but even if it is too much, water will drip off, so it is preferably 100% or less.

In this way, the fiber web to which the required moisture has been imparted is blown with a jet air stream at the next air nozzle 6.

This jet air blowing device is an entanglement reinforcing device that entangles the constituent fibers of the fiber web with each other, and is a main part of the present invention.
As shown in FIG. 2, the exhaust perforated plate 7 is fixed to the lower part of the conveyor net 5 which runs at a constant speed, and the upper part has a perforated exhaust plate 7. The fiber web W, which has a nozzle bar 11 provided with an air groove 12 and a nozzle hole 13, and which moves together with the conveyor net 5 from left to right in the figure at a constant speed, generates high-pressure air (not shown). High-pressure air sent from a source through a pipe and filling an air groove 12 is injected through a number of nozzle holes 13 arranged in a row at the bottom of a nozzle bar 11.

Here, a large number of nozzle holes 13 provided in a row form a plate having nozzle holes 13 arranged in a row shape.
They are made by arranging them in the width direction of a fiber web, and a plurality of them are arranged as needed.

The nozzle bar 11 may be fixedly arranged, or may be traversed in a direction perpendicular to the running direction of the web, if necessary. This traverse prevents the portions that are entangled by the air jet from forming streaks.

Various types of mesh are used for the conveyor 5 depending on the purpose, but a net-like fabric made of stainless steel wire is particularly suitable, and is usually formed into an endless belt shape on which the fibrous web W is placed. Run.

Further, the exhaust perforated plate 7 fixed to the lower part of the conveyor 5 of the above-mentioned entanglement reinforcement jet air flow blowing device is a rigid structure that holds the conveyor 5 horizontally from the lower part, and allows the air injected from the nozzle hole 13 to be It also has the role of discharging some of the moisture in the web.

In addition, in the above-mentioned air flow blowing, the temperature of the air flow is generally used at room temperature, but if a part of the fiber web contains low melting point fibers, the low melting point fibers are fused together with the entanglement, and the entanglement is fixed. It is also possible to increase the degree.

The fibrous web thus blown by a jet air stream and entangled by the device described above is then passed through a squeeze roll 8 to squeeze out the excess water and then passed through a dryer 9.
After drying, the nonwoven fabric is wound up into a roll on a winding machine 10 to form the entangled nonwoven fabric intended by the present invention.

Next, specific examples using the above method will be listed.

2.5d x 51mm 100% polyester short fibers are used as raw material fibers, passed through 2 cards to form a fiber web, 8 crosslays, 2.5x draft to adjust fiber orientation and fabric weight, web width 100cm, fabric weight. The fiber web weighed 100 g/m ² .

This web was then made to contain 80% water by weight and sent to a subsequent air blowing device, at a web speed of 15%.
Air jet injection was performed under the manufacturing conditions of air pressure 12Kg/cm ² at m/min, nozzle diameter 0.2mm, nozzle pitch 10mm, 4 nozzle bars, and nozzle traverse 25mm (6 times/min), followed by squeezing and drying. A nonwoven fabric was manufactured through each normal process.

The resulting nonwoven fabric has a width of 90 cm and a basis weight of 120
g/m ² , and when the tensile strength was measured, it was found to be 5.2 kg/2.5 cm in average length and width, which was comparable to nonwoven fabric obtained by the waterjet method.

(Effects of the Invention) As described above, the present invention provides the following steps in the production of nonwoven fabrics:
Instead of spraying waterjet onto the fiber web, this method wets the fiber web with water and then blows airflow from a nozzle onto it to entangle the fibers. Not only does it make it more flexible, it also temporarily increases the cohesiveness of the fibers using the surface tension of water.
During the next blowing of the jet air stream, the air stream gives momentum to the water between the fibers, and the air stream gives momentum to the water between the fibers.
In addition, it has a remarkable effect of promoting the entanglement of fibers more than a waterjet and improving the intertwining of the fibers of the nonwoven fabric.

Furthermore, unlike the water jet method, which uses water jetting, the method of the present invention does not require a large amount of water because of water impregnation and air flow jetting. /1000 of water is sufficient, therefore there is no need to install water treatment equipment necessary for water reuse, equipment costs are low, energy consumption is low, and energy saving effects are expected.

Furthermore, since the method of the present invention uses pressurized air, unlike a water jet, there is no risk of nozzle clogging and there is an advantage of improved workability.

Since the method of the present invention is a method using air jet blowing, it goes without saying that the processing speed is higher and the chance of fiber damage is lower than that of chemical bond needle punching or the like.

[Brief explanation of the drawing]

FIG. 1 is a process outline diagram showing one example of the manufacturing process of the nonwoven fabric of the present invention, and FIG. 2 is a detailed view, partially in cross section, of an air flow blowing device that is an important part of the method of the present invention. W... Fiber web, 3... Soaking tank, 4... Squeezing roll, 5... Conveyor, 6... Air nozzle, 7... Exhaust porous plate, 11... Nozzle bar, 12... Air groove, 13
...Nozzle hole.

Claims (1)

[Claims] 1. When manufacturing a nonwoven fabric by running a fibrous web and intertwining the fibers constituting the web with each other during running, the fibrous web is made to contain moisture in an amount of 50 to 100% by weight of the fibers. A method for manufacturing a nonwoven fabric, which comprises running a nonwoven fabric in a state in which the fibers are stranded, and blowing air jet from a nozzle onto the fabric to entangle the fibers with each other.