JPS5843502B2 - Kaikoufushiyokufuno Seizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for manufacturing a perforated nonwoven fabric that does not use a special binder and has excellent physical performance due to friction resistance and/or entanglement between the constituent fibers. be.

In the production of non-woven fabrics, methods have been proposed for a long time to produce open-pore non-woven fabrics with excellent strength, flexibility, etc. only by the friction resistance and/or entanglement between fibers without using a specific binder. Some of them have already been put into practical use.

For example, Japanese Patent Publication No. 36-7274 proposed a method of applying a fluid flow to a fiber web using a conical nozzle, and Japanese Patent Publication No. 47-18069, which was an improvement patent on the method, proposed a method of applying a fluid flow to a fiber web using a conical nozzle. It teaches how to make it work.

However, in the former method using a conical nozzle, the impact work at the impact surface of the fluid stream on the fiber web is strongest at the center of the impact surface and decreases dramatically toward the periphery, so it is difficult to produce wide products. When manufacturing uniformly and efficiently,
It is necessary to use a large number of nozzles in an intersecting manner,
In addition, due to the dispersion of force, the forming efficiency and the efficiency of intertwining between fibers are poor, resulting in a low processing effect.

As a method to improve this drawback, the authors proposed a treatment using a fine columnar flow having a high momentum per unit cross-sectional area, instead of a spray-like flow using a conical nozzle.

However, when considering the thickness of the constituent fibers and the force required to move each columnar flow, the method proposed by Hou et al. Therefore, this type of nonwoven fabric manufacturing method, which is formed by rearranging the fibers by water treatment and subsequent entanglement of the fibers, has a small impact force. It was efficiency.

The present inventors investigated the treatment of fiber webs using liquid flow, focusing on improving the efficiency of the treatment, and found that a jet pressure of 5 kg/crr1 or more was sprayed from an orifice onto a fiber web placed on a support plate having a large number of mold holes. and the collision surface of the fiber web has a ratio b of the major axis a to the minor axis
/a is 1/4 or less of the atomized liquid flow from 0.2 to 15
．． It has been found that by supplying and processing at 0 J/m-Cm, the shaping effect of the fiber web and the entanglement between fibers are dramatically improved.

The atomized liquid stream referred to in the present invention is one in which the fluid ejected from an orifice is intermittently or continuously supplied in the form of separated particles.

In addition, a flat spray-like liquid flow is one in which the spray state of the liquid flow is fan-shaped, and the impact surface on the fiber web forms a circular or rectangular shape.In the present invention, the shape is defined as a circular shape. It was defined by its major axis (a) and minor axis (b).

However, the shape may be a rectangle, in which case the major axis is replaced by the long side, and the minor axis is replaced by the short side.

Also, the Sui circle may be slightly distorted or come and go, but in that case, the average diameter shall be used as the major axis and minor axis.

In the present invention, when the b/a ratio is greater than 1/4, the flow resembles a spray-like liquid flow from a conical nozzle, and no improvement in treatment effect can be obtained.

A flat atomized liquid stream can be easily formed using a spray nozzle with a flat orifice as shown in Fig. 1 or a spray nozzle with a rectangular orifice as shown in Fig. 2, and in this case b/a is 1/4 or less. To make it, select the size of L and 1 appropriately (for example, L is 271111.1 and 1 mm)
This can be easily done by a person skilled in the art.

The impact force of the fluid stream on the fiber web is defined as the product of the flow rate of the fluid supplied per unit time and the fluid velocity, and as they increase, the impact force increases.

Here, the fluid flow rate is 0.2 l/min, cr
l1 or more 15, Ol /min, c4 or less, preferably 0.51/Trim, crti or more 10.07
3/yrin·cA or less.

That is, the flow rate to the web is 0.273/mi! t
If the fluid velocity is less than -c4, it is difficult to rearrange the fibers that make up the web no matter how high the fluid velocity is.
If it exceeds 1/min crl, there is a limit to the drainage of the fiber web to be treated, and the fiber web will be submerged in a flood condition.
It becomes difficult to continue stable processing.

Next, the flow velocity increases as the injection pressure increases, and decelerates due to air resistance while the fiber web advances from the nozzle outlet. However, no matter how close the nozzle outlet and the fiber web are, Flow velocity is 20m/see
, that is, if the injection force is less than 5 kgA4, it is difficult to obtain a treatment effect no matter how low the flow rate is.

Note that the above-mentioned flow rate refers to the amount of the fluid supplied per unit area on the collision surface.

The supporting plate having a mold hole according to the present invention has a circular or circular mold hole, and the average circumference of the mold hole is one of the support plate 1.
It is preferable to have at least 0.1 crn per crtl and a large number of mold holes.

Further, the support plate may be a flat plate, a belt, or a screen.

Thus, in the present invention, a fibrous web placed on a support plate having a large number of mold holes is injected from an orifice at an injection pressure of 5 ky/crA or more, and the ratio of the major axis a to the minor axis of the impact surface to the fibrous web is A flat atomized liquid stream with b/a of 1/4 or less is applied to the fiber web from 0.2 to 15.
The fibrous web is processed by supplying at 0 J/mm/crA, and the fibers are rearranged and intertwined to produce a nonwoven fabric with excellent physical performance. A perforated screen may be superimposed underneath the plate or, if necessary, above the fibrous web.

The perforated screen placed under the support plate referred to herein has holes substantially smaller than the dimensions of the holes in the perforated support plate, and the liquid passing through the web can be removed without resistance. It may be made of any material such as wire mesh, synthetic fibers, etc.

The screen placed over the fibrous web may be of any type that does not significantly impede the impact force of the fluid stream on the web.

In the present invention, the angle of impingement of the fluid stream against the fiber web is preferably an incident angle of 90' for efficiency, and preferably at least an incident angle of 45° or more.

The fibers referred to in the present invention include artificial fibers such as rayon, acetate, nylon, vinylon, polyester, acrylic, and polyolefin, natural fibers such as cotton, pulp, hemp, silk, and wool, as well as glass fibers and asbestos. It may be any kind of mineral fiber, etc., or a mixture thereof, but in consideration of further density improvement and provision of interfiber adhesion in the shield process, fibers with latent shrinkage or fibers with latent shrinkage,
It is desirable to use fibers that exhibit self-adhesive properties when heated or the like.

Although the fiber form may be of any type, the single fiber fineness is 15 deniers or less, preferably 6 deniers or less, and the smaller the fineness, the more efficient the present invention is.

There is no particular restriction on the fiber length, and a short fiber web, a continuous filament web, or a combination thereof may be used.

The liquid stream referred to in the present invention is preferably water.

Further, this liquid stream may have a sticky agent, a glue, etc. dissolved therein as required, and may also contain as fine a powder as possible.

The nonwoven fabric thus obtained has excellent strength because it is perforated in a pattern according to the mold holes, and the fibers are entangled by the impact of the fluid.Since it is binder-free, it is highly flexible and can be easily used in manufacturing processes and products. There is no concern about pollution, and it is a nonwoven fabric with a wide range of applications.In addition to being widely used for conventional nonwoven fabrics such as interlining and base fabric, furniture decoration, and curtains and other tray applications, it can also be used for clothing. Furthermore, if necessary, heat treatment, binder treatment, dyeing, printing, etc. can be applied to expand the application to materials, etc.

The present invention will be explained in more detail with reference to Examples below.

Example This example shows a method for manufacturing a perforated nonwoven fabric with excellent properties such as flexibility and strength, and it is important to use a flat orifice in order to achieve the effects of the present invention. This indicates that

The fiber web is polyester fiber with a single fiber fineness of 1.5d.
A web with a basis weight of about 100 P/m was obtained by cross-layering two carded webs composed of fibers with an average fiber length of 53 mm.

This was placed on a support plate with an average circumference of 7 holes per 1 crA (46 holes per 1 nch2), a coarse mesh was placed on top of the support plate, and a nonwoven fabric with holes was made by spraying water, and then dried at room temperature. A nonwoven fabric with excellent flexibility, texture, strength, etc. was obtained.

&1 to 3 are those using conical nozzles, and Ken 4 to 10
is treated with a flat orifice.

In addition, 11 to 15 are processed using columnar flow. became.

As seen in the table, it can be seen that when a conical nozzle is used, it is less efficient than the present invention when manufacturing a nonwoven fabric having a large number of holes.

Furthermore, when a columnar flow is used, the strength is improved due to the needle insertion effect of the fluid, but the production becomes inefficient in terms of shapeability.

Also, as seen in Shoes 4 to 6, the closer the ratio b/a of the short axis to the long axis of the impact surface due to the fluid approaches 1/4, the greater the effect.
It can be seen that this is similar to the case using a conical nozzle.

Although the processing was carried out with the distance between the Unilough and the nozzle being 10 mm, it is also possible to control the amount of feed to the web by changing this distance.

[Brief explanation of the drawing]

1 and 2 are plan views showing various orifice shapes of the flat atomized liquid stream spray nozzle used in the present invention.

Claims (1)

[Claims] 1 The injection pressure from the orifice to the fibrous web placed on a support plate having a large number of mold holes is 5 kg/crri or more, and the ratio b/a of the major axis a to the minor axis of the impact surface to the fibrous web is A flat atomized liquid flow of 1/4 or less is supplied to the fiber web in an amount of 0.2 to 15, Q, l:
7m1yt-(171) A method for producing a perforated nonwoven fabric.