JPH02277867A - Production of nonwoven mat - Google Patents

Abstract

PURPOSE:To obtain the title mat prevented in falling of a metallic fiber, remarkably improved in tensile strength and useful for sound insulating material, etc., by forming a mixed fiber of a specific fiber for binding and metallic fiber in a shape of mat and applying heat or electromagnetic wave thereto. CONSTITUTION:A mixed fiber of a binding fiber curable by applying heat or electromagnetic wave and metallic fiber is formed into a nonwoven mat and heat or electromagnetic wave is applied to the formed article and the binding fiber is cured to provide the aimed mat. Furthermore, the mixed fiber is sprayed into a mat substrate to embed the mixed fiber in the mat substrate and then heat or electromagnetic wave is preferably applied to the mat substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing a nonwoven mat using metal fibers.

(Prior art) This type of non-woven mat using metal fibers is known to be one in which metal fibers are molded into a predetermined shape, and one in which metal fibers are attached to a mat base material of a predetermined shape made of glass fiber or the like. It is being These non-woven mats are used as soundproofing materials, thermal conductive materials, reinforcing materials,
It is widely used as a filter in various fields.

The former non-woven mat is produced by forming a large number of metal fibers with lengths from several I to several tens++ i into a sheet using a roller or press (dry method), or by molding the same metal fibers into a sheet with water.

A dispersion liquid dispersed in a liquid such as alcohol is suctioned by negative pressure through a porous mold, liquid bones are removed from the dispersion liquid, and metal fibers are directly molded into the mold and dried (151 method). It is formed. In either method, if necessary, a needle punch with a large number of J-shaped needles is punched through the formed nonwoven mat to strengthen the intertwining of the metal fibers and improve the tensile strength. There is.

The latter non-woven mat is produced by scattering a large number of metal fibers of several to several tens of I on the surface of a non-woven mat base material made of glass fibers, and using a needle bunch similar to the above to separate the metal fibers. It is formed by embedding it in a matte base material.

(Question 8 to be solved by the invention) By the way, a common problem with conventional non-woven mats using metal fibers, regardless of their use, is ``insufficient tensile strength.''
and "falling of fibers", and both of these problems occur due to insufficient bonding strength between the metal fibers. As mentioned above
Conventionally, this problem has been improved by punching the non-woven mat or mat base material after forming with a needle punch to strengthen the intertwining of metal fibers, but when punching with a needle punch, the fibers fall off. For this reason, we cannot expect much of an effect at present.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing a nonwoven mat that has high tensile strength and does not cause metal fibers to fall off.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides the following in claim (1):
A non-woven mat is produced by forming a mixture of metal fibers and binding fibers that harden by applying heat or electromagnetic waves into a non-woven mat shape, and then applying heat or electromagnetic waves to the molded product to harden the binding fibers. is manufactured.

Furthermore, in claim (2), a fiber mixture of bonding fibers that harden by application of heat or electromagnetic waves and metal fibers is dispersed on a mat base material, and after the mixed fibers are embedded in the mat base material, the mat A nonwoven mat is manufactured by applying heat or electromagnetic waves to the base material to harden the binding fibers.

(Function) According to the manufacturing method of the present invention, the bonding fibers contained in the mixed fibers are cured while being entangled with the metal fibers by the provision of heat or electromagnetic waves, thereby increasing the bonding force between the metal fibers. improves.

(Example) A method for manufacturing a nonwoven mat made of metal fibers will be described below with reference to FIG.

First, as shown in FIG. 1(a), a nonwoven mat-like molded article 1 is obtained from a mixed fiber of metal fibers and binding fibers.

The mixed fibers are a mixture of approximately equal amounts of brass metal fibers with an aspect ratio (length/diameter) of around 500 and phenolic resin binding fibers with the same aspect ratio and a curing temperature of approximately 180°C. This is what I did. The length of each fiber varies depending on the purpose of use of the nonwoven mat, but if you are expecting to improve the tensile strength due to the entanglement of metal fibers,
Preferably, the length is about mm to 501 m.

Each of these fibers is fixed by wrapping a thin band-shaped brass metal plate with a thickness of about 100 μI around a rotating shaft many times with a phenol resin film of the same thickness in between. can be easily obtained by producing long fibers by a so-called rotary cutting method in which the end face of a metal plate is cut together with a film, and then cutting the long fibers with an appropriate cutting machine.

In order to obtain the molded article 1, the mixed fibers are spread out into a flat shape and pressed into a predetermined shape by using a roller or a press (dry method), or the mixed fibers are mixed with water,
A dispersion liquid dispersed in a liquid such as alcohol is sucked through a porous mold using a negative and positive force, the liquid content is removed from the dispersion liquid, and the mixed fiber is directly molded into a mold and dried (wet method).
.

Next, as shown in FIG. 1(b), a needle punch 2 equipped with a large number of J-shaped needles 2a is punched into the upper surface of the molded article 1 to strengthen the intertwining of the metal fibers and the binding fibers.

Next, as shown in FIG. 1(C), this molded product 1 is placed in a heating furnace (not shown) and heated at a temperature slightly higher than the curing temperature of the binding fibers, for example, about 200° C., for a predetermined time. The binding fibers are softened and then hardened. In the above manner, the nonwoven mat 3 made of metal fibers is manufactured.

As described above, according to this embodiment, the binding fibers contained in the mixed fibers can be cured by heating, and can be cured while being entangled with the metal fibers, and the binding fibers can be cured when softened before curing. can be attached to the metal fibers, and together with the intertwining of the metal fibers, the metal fibers are firmly bonded, thereby greatly improving the tensile strength of the nonwoven mat 3, and also preventing the metal fibers from falling off. can be reliably prevented.

Further, since the binding fibers are cured in substantially the same linear form without changing their linear form, the air permeability of the nonwoven mat itself is not hindered.

Furthermore, by manufacturing the metal fibers and the binding fibers by a rotary cutting method, it is possible to obtain fibers that are three-dimensionally curled and have a rough fiber surface, which particularly enhances the entanglement of the metal fibers. It is possible to exhibit even higher tensile strength.

Furthermore, when manufacturing fibers using the rotary cutting method, the mixing ratio of metal fibers and binding fibers in the mixed fibers can be easily adjusted by changing the lamination ratio of the materials wrapped around the rotating shaft. The work involved can be simplified.

Next, a method for manufacturing a non-woven mat made of metal fibers and a mat base material will be described with reference to FIG.

First, as shown in FIG. 2(a), mixed fibers 5 of metal fibers and binding fibers are uniformly sprinkled on the upper surface of a nonwoven mat base material 4 made of glass fibers.

The mixed fibers 5 are similar to those in the embodiments described above, and are obtained by appropriately cutting fibers produced by a rotary cutting method.

Further, the mixed fibers 5 may be dispersed by using a suitable scattering device or by the wet method described above.

Next, as shown in FIG. 2(b), a needle bunch 2 similar to that described above is inserted into the upper surface of the mat base material 4, and the mixed fibers 5 are embedded in the upper surface of the mat base material 4.

Next, as shown in FIG. 2(C), this mat base material 4
is placed in a heating furnace (not shown) and heated for a predetermined time at a temperature slightly higher than the curing temperature of the bonding fiber, for example, about 200° C., to soften and then harden the bonding fiber. In the above manner, a non-woven matturo made of metal fibers and a matte base material is manufactured.

In this embodiment as well, the same effects as in the previous embodiment can be achieved.

In the above examples, the binding fibers were made of a thermosetting phenolic resin, but the binding fibers can be made of other thermosetting resins as well as having the property of being hardened by heating. It may be made of other materials than resin.

Furthermore, the binding fibers are not limited to those that harden through the application of heat; the same effect as described above can also be achieved by forming them from materials that harden through the application of electromagnetic waves, such as photocurable resins that harden through the irradiation of light such as ultraviolet rays. be able to.

Furthermore, it goes without saying that the metal fibers may be made of a metal other than brass depending on the purpose of use of the non-woven mat, and the metal fibers, including the binding fibers, may be manufactured by a manufacturing method other than rotary cutting. You may also use

Furthermore, as a final step, a sheet-like reinforcing material may be attached to one surface of the nonwoven mat for reinforcement.

(Effects of the Invention) As explained above, according to the present invention, the binding fibers contained in the mixed fibers can be cured by heating, and can be cured while being entangled with the metal fibers. Together with the intertwining of the fibers, the metal fibers are strongly bonded, thereby significantly increasing the tensile strength of the nonwoven mat and having the effect of reliably preventing the metal fibers from falling off.

Further, since the binding fibers are cured in substantially the same linear form without changing their linear form, the air permeability of the nonwoven mat itself is not hindered.

[Brief explanation of drawings]

FIG. 1 is a manufacturing process diagram showing a method for manufacturing a non-woven mat made of metal fibers, and FIG. 2 is a manufacturing process diagram showing a method for manufacturing a non-woven mat made of metal fibers and a mat base material. 1... Molded product, 3, 6... Nonwoven mat, Yotsukawa mat base material, 5... Mixed fiber. Patent applicant: Nipex Co., Ltd. Akira Yanagisawa

Claims (2)

[Claims] (1) Molding a mixed fiber of metal fibers and binding fibers that harden by applying heat or electromagnetic waves into a nonwoven mat shape, and applying heat or electromagnetic waves to the molded product to harden the binding fibers. Characteristic method for manufacturing non-woven mats. (2) Sprinkle mixed fibers of binding fibers and metal fibers that harden by applying heat or electromagnetic waves onto the mat base material, embed the mixed fibers in the mat base material, and then apply heat or electromagnetic waves to the mat base material. A method for producing a non-woven mat, characterized in that the bonding fibers are cured by providing a bonding fiber.