JPH02232306A - Manufacture of metal fiber for manufacturing nonwoven mat - Google Patents

Abstract

PURPOSE:To continuously manufacture metal fiber for nonwoven mat providing suitable toughness by rotating a rotating shaft winding metal-made strip material by multiple turns toward reverse direction to the winding direction and cutting end face of the winding material with a cutting edge. CONSTITUTION:The metal material of brass-made strip, etc., is tightly wound to a main shaft 10 by multiple turns and the end part thereof is fixed to the surface of the shaft. The main shaft 10 is rotated toward reverse direction to the winding direction of the winding material 20 at the fixed velocity. The cutting edge 51 is pushed to the end face 20a of winding material 20 to cut each layer of the metal material 20 concentrically laminated at the same time. By this method, long fiber having fiber diameter according to the thickness of winding material 20 can be continuously manufactured. At the time of forming this metal fiber to the suitable shape, sufficient strength is displayed with mutual combination caused by interwining among themselves and the nonwoven mat without any detaching of the fiber can be manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing metal fibers suitable for producing non-woven mavto.

(Prior art) This type of non-woven mat using metal fibers includes those formed only with metal fibers and those formed as a composite material by attaching metal fibers to other non-woven mats made of glass fibers, etc. These materials can be shaped into desired shapes and used as soundproofing materials, sealing materials, electromagnetic wave shielding materials, thermal conductive materials, reinforcing materials,
It is widely used as a filter in various fields.

This nonwoven mat is usually manufactured by a dry method or a wet method. A conventional method for manufacturing this type of nonwoven mat will be described below.

When a non-woven mat is formed using only metal fibers using the former dry method, a predetermined amount of metal fibers is appropriately formed using a roller or press, and when using the latter wet method, a non-woven mat is formed using only metal fibers. In this case, the metal fibers are dispersed in a liquid such as water or alcohol, and the liquid is removed from the dispersion by suctioning the dispersion liquid through a porous mold using negative pressure. It is molded directly into the In any case, if necessary, a needle punch with a large number of J-shaped needles can be inserted and removed from the formed nonwoven mat to increase the intertwining of the metal fibers and improve the strength (tensile strength). I'm trying.

In addition, when metal fibers are attached to another non-woven mat to form a non-woven mat as a composite material, the metal fibers are dispersed onto a non-woven mat made of glass fiber, for example, by the above-mentioned dry method or wet method. A similar needle punch is inserted into and removed from the nonwoven mat to embed the metal fibers into the nonwoven mat.

(Problems to be Solved by the Invention) By the way, non-woven mats using metal fibers have problems common to all uses, such as "insufficient strength" and "falling of fibers."

All of these problems are caused by a lack of intertwining between metal fibers. In other words, if the metal fibers are straight and the fiber surface is smooth, it is impossible to expect the metal fibers to intertwine with each other. The strength is low and the fibers tend to fall off. Therefore, in order to obtain a non-woven mat of good quality, it is preferable that the metal fibers are three-dimensionally curled and that the fiber surface has a rough surface with a sufficient coefficient of friction. It is desirable that the material has such toughness that it will not break under the bending stress it is subjected to.

Conventionally, a pultrusion method has been known as one of the methods for producing metal fibers used in these nonwoven mats.

However, in order to obtain small-diameter metal fibers used in non-woven mats using this method, the number of drawings increases and the number of intermediate annealing processes also increases, making the metal fibers very expensive and making the fiber surface rough. Because it is smooth, there is a problem in that it is difficult to produce a nonwoven mat that has high strength and does not have fibers falling off.

Furthermore, a wire cutting method is known as one of the other methods for producing the metal fibers. However, since this method generates fibers by cutting a long metal wire pulled in one direction along the wire, it is difficult to use low-strength materials due to the manufacturing method. , copper and f, which have excellent electrical and thermal properties and are suitable for use as non-woven mats because they are less closed, are suitable for non-woven mats.
There is a problem in that it is not suitable for producing metal tatIf1 such as R copper. In addition, since the depth of cut changes due to vibrations during cutting and the diameter of the produced fibers tends to vary, it is difficult to mass-produce non-woven mats with stable quality even when using metal fibers produced by this method. The problem is that I can't.

Furthermore, as one of the other methods for producing the metal fibers, a method such as a chatter vibration cutting method in which a metal block is cut with a cutting blade having an uneven or step-like blade is known. However, with this method, it is difficult to obtain three-dimensionally curled metal fibers, so there is a problem that it is impossible to produce a nonwoven mat with high strength and no fibers falling off using short metal fibers. In addition, as with the wire cutting method, the diameter of the fibers produced tends to vary, so even if metal fibers produced by this method are used, it is not possible to mass-produce non-woven mats with stable quality. be.

The present invention has been made in view of the above-mentioned problems, and it is possible to produce a non-woven mat with high strength and no shedding of fibers by fully exploiting the intertwining of metal fibers, and also to produce a non-woven mat with stable quality. It is an object of the present invention to provide a method for manufacturing metal fibers suitable for manufacturing non-woven mats that can mass-produce woven mats at low cost.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a step of winding a thin metal strip material around the outer surface of a rotating shaft many times parallel to the axis of the rotating shaft; The method includes a step of rotating a shaft in a direction opposite to the winding direction and cutting an end face of the wound material with a cutting blade to produce a long fiber, and a step of appropriately cutting the long fiber. It is characterized by

(Function) According to the present invention, a rotating shaft on which a thin metal strip material is wound many times is rotated in a direction opposite to the winding direction, and the end face of the wound material is cut with a cutting blade. By this method, it is possible to continuously produce long fibers having fiber diameters corresponding to the wall thickness from metal materials of various strengths wound around a rotating shaft, and by cutting these long fibers as appropriate. , it is possible to produce metal fibers that are three-dimensionally curled, have a rough fiber surface, and have appropriate toughness. Then, the metal fibers are formed into a suitable shape to produce a nonwoven mat.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

First, a cutting device for producing long fibers and the production of long fibers will be described with reference to FIGS. 1(a) to 1(e).

In the figure, reference numeral 1 denotes a hollow rectangular bed placed on the floor etc. On the upper surface of the bed 1, a bearing stand 2 and a support stand 3 each housing a bearing (not shown) are placed at a predetermined interval. The bearings are arranged so that the bearings are located on the same axis.

Reference numeral 10 denotes a main shaft formed in a multi-stage shape, and the main shaft 10 is rotatably supported at its right end in the figure by the support stand 3 and at its left end in the figure by the bearing stand 2. Further, in the portion of the main shaft 10 located between the bearing stand 2 and the support stand 3,
It has a cylindrical outer surface whose axis coincides with the main shaft 10, and an axial groove 1. 1a, and a large-diameter flange 12 is provided on the bearing stand 2 side of the winding portion 11. The groove 11a has a width and depth sufficient to allow an end portion of a metal material, which will be described later, to be inserted and engaged therein. Further, a thin band-shaped metal material is wound many times around the winding portion 11 (hereinafter, the wound metal material will be referred to as a wound material 20). Furthermore, the portion of the support shaft 10 protruding from the bearing stand 2 is provided with two bollards 13 having different diameters.
14 are fixed concentrically.

For example, the metal material has a thickness of 100μ1 and a width of 100μ1.
The wrapping portion 11 is made of a thin brass plate.
When wrapping the metal material around the flange, the end of the metal material is inserted into the groove 11a and bent, and the metal material is wound clockwise as shown in FIG. Wrap tightly in the direction many times. The diameter of the wound metal material is approximately 180 l.
In the case of Il, it is cut at about 2001 Im, for example, and the end is fixed to the surface. In addition to using an adhesive, spot welding, laser welding, or the like can be used for this attachment.

Reference numeral 30 denotes a main shaft driving motor fixed to the lower part of the bed 1, and a rotary shaft 31 of the motor 30 has a bolt 32 fixed thereto. This bobbin 32 and the bobbin 1 of the main shaft 10
3 are connected via a belt 33, that is, the main shaft 10 can be rotated by operating the motor 30.

Reference numeral 40 denotes a speed reducer which is fixed to the upper part of the bed 1 and has a connecting means (not shown) such as an electromagnetic clutch inside. This booster 42 and the pulley 14 of the main shaft 10 are connected via a belt 43, that is, the rotation of the main shaft 10 is transmitted to the input 11b41 of the reducer 40 when the main shaft 10 is rotating. It has become. Further, a feed screw 44 parallel to the axis of the main shaft 10 is connected to an output shaft (not shown) of the speed reducer 40 .

Reference numeral 50 denotes a tool rest equipped with a cutting blade 51 made of high-speed steel or cemented carbide, and the tool rest 50 slides on a guide rail 4 arranged parallel to the axis of the main shaft 10 on the upper surface of the bed 1. It has a guide groove 52 on the lower surface that can be freely fitted into it. Further, a leg plate 53 is provided on the lower surface of the tool rest 50 and projects downward through an elongated hole (not shown) in the guide rail 4, and a feed nut 54 screwed onto the feed screw 44 is mounted on the leg plate 53. It is fixed. That is, the tool rest 50 is moved along the guide rail 4 by the rotation of the feed screw 44 into the bed 1.
The upper surface can be slid parallel to the axis of the main shaft 10.

The blade line 51a of the cutting blade 51 has an extension line shown in FIG.
As shown in b), it is perpendicular to the axis 10a of the main shaft 10, and is in contact with the center position in the height direction of the end surface (cut surface) 20a of the wound material 20. Also, the angle (rake angle) γ between the rake surface 51b of the cutting blade 51 and the axis 10a is 21''
It is set appropriately within the range of ~371, and the cutting blade 5
The angle (front relief angle) α between the flank 51c of the winding material 1 and the end face 20a of the wound material 20 is set to about 10''.

Further, although not shown, a cavity is formed inside the main shaft 10 extending from the end face where the pulleys 23 and 24 are fixed to the winding part 11, and within the cavity there are two holes for supplying and draining cooling water.
A heavy vibrator is inserted in a watertight manner, and when the bomb is activated, water is supplied from the inner vibrator into the cavity, and this water can be sucked in and circulated by the outer vibrator. This cooling structure prevents changes in cutting conditions due to heat generated during cutting, such as changes in feed amount due to thermal expansion of the wound material 20, and can cool the main shaft 10, especially the wound portion 11. It looks like this.

The operation of the cutting device will be explained below.

First, the rotor 40 is activated to rotate the main shaft 10 at a constant speed in a counterclockwise direction as shown in FIG. 1(e), that is, in a direction opposite to the direction in which the wound material 20 is wound.

If the input shaft and output shaft of the reducer 40 are connected in this state, the rotation of the feed screw 44 interlocking with the main shaft 10 moves the tool rest 50 along the guide rail 4 to the end surface 20a of the wound material 20.
It can be sent at a constant speed in any direction. As a result, the cutting blade 51 is pressed against the end surface 20g of the wound material 20, and each layer of the metal material layered approximately concentrically is cut simultaneously.
Long fibers having a fiber diameter corresponding to the thickness of the wound material are continuously produced.

To explain with specific numerical values, when using a thin brass plate with a thickness of 100μ1, the cutting width is 18mm,
Feed of cutting blade 51 ffio. 01a+m/rev1
At a cutting speed of 90 m/win, it is possible to produce approximately 7.5 kg/h of long fibers with a fiber diameter of approximately 100 μm, and by doubling the feed rate, approximately 15 kg/h of long fibers can be produced. It becomes possible.

In addition to brass, materials that can be cut by the cutting device can be selected from various metals such as copper, iron, tungsten, aluminum, nickel, titanium, and alloys thereof, and two or more types of metals can be used as necessary. A combination of laminated and wound materials may be used.

Further, in order to perform the cutting well, it is necessary to appropriately select the rake angle γ of the cutting blade 61 described above. Table (1) below. (2) is the same metal material as above with a diameter of 15 mm.
0 mm wrapping portion 11 until it has a diameter of about 180 mm, the rotation speed of the spindle 10 is 150 rpm, the cutting width is 13 + ms, the front relief angle α is constant at 10, and the feed rate of the cutting blade 61 is 0.01 s. ■/r8V and 0. 0 2 m
These are experimental results showing the state of fiber formation and the decrease in the rotational speed of the main shaft depending on the rake angle γ when m/rev.

Table (1) (Feed amount 0.OLsm/rev) Table (
2) (Feed rate 0.02mm/rev) In this way, when the feed rate is 0 and the rake angle γ is 20'' or less, the cutting resistance increases and the heat generated due to it causes mutual damage. Short fibers were produced that were welded to the fibers, and the rotational speed of the main shaft 10 also decreased by about 10 rpm.

Further, when the rake angle γ is 38@ or more, the rotational speed of the spindle 10 does not decrease so much, but chatter occurs during cutting, making it difficult to produce long fibers. When the rake angle γ is between 21 and 37 degrees, the number of revolutions of the main shaft 10 decreases when the angle is small, producing fibers that are somewhat inflexible, but it is possible to obtain long fibers of approximately good quality. It was confirmed that especially when the rake angle γ is 35°, the rotational speed of the main shaft 10 does not decrease much and the fiber condition is the best.

On the other hand, if the feed amount is 0. 0 2 ■/rev, although the reduction in the rotational speed of the spindle 10 is slightly different, almost the same results are obtained, and good fiber production is possible when the rake angle γ is in the range of 21 to 37@, especially when the rake angle is γ is 35
It was confirmed that the @ case is the most appropriate.

By the way, when producing finer fibers using the cutting device, it is necessary to wind a thinner metal material around the winding part 11, but considering the manufacturing technology of the material, it is necessary to wind a thinner metal material with a thickness of 100 μm. It is relatively difficult to obtain the following materials,
Moreover, as the thickness increases, the price also becomes extremely high, so in such a case, it is preferable to employ a laminated rolling apparatus as shown in FIG.

In the figure, 60a and 60b are cylindrical rolling rollers, and the rolling rollers 60a and 60b are disposed facing each other in the vertical direction with their axes parallel to each other and with a predetermined interval S between them. Further, the rolling mills 60a and 60b can be rotated in opposite directions and at the same speed by a drive motor (not shown).

Lamination rolling in the lamination rolling apparatus is performed by laminating a plurality of thin plates and rolling the laminated plates. For example, in the case where a laminate KSI is constructed by stacking a total of four belt-shaped brass thin plates each having a thickness of about 100μ1, the laminate KS1 is supplied to the rolling rollers 60a and 60b for rolling. The rolling dimension S of the rollers 60a and 60b is 10
By setting the value to 0 μm, a rolled laminate KS2 with the same dimensions as this can be obtained by rolling, so that an extremely thin material with a thickness of approximately 25 μm per sheet can be rolled into 4
It becomes possible to simultaneously produce two sheets in a laminated state. Therefore, by winding this around the winding portion 11 and cutting it in the same manner as described above, it becomes possible to continuously produce finer long fibers having a fiber diameter of approximately 25 μm.

Next, cutting of the long fibers will be explained.

For this cutting, it is basically possible to use various well-known cutting machines as long as they have cutting blades that are harder and more rigid than the fibers to be cut. However, when cutting a large amount of fibers in a short time, is a cutting machine with a mechanism similar to that of a paper shredder, that is, a plurality of circular cutting blades are arranged in parallel with two rotating shafts fixed at predetermined intervals, and the cutting blades are arranged in mesh with each other. It is better to use a machine.

By cutting the long fibers, the fibers are three-dimensionally unified;
Moreover, metal fibers having a rough fiber surface and appropriate toughness can be produced with a predetermined length.

This cutting length varies slightly depending on the purpose of use of the non-woven mat, but if you are looking for strength due to the intertwining of metal fibers, a mat with an aspect ratio (length/diameter) of around 500 will take about 2 to 50 ms. preferable. If it is less than this range, we cannot expect much strength from the intertwining of metal fibers,
Moreover, if it exceeds this range, strength deviation is likely to occur due to uneven fiber dispersion, and there is a possibility that moldability may deteriorate.

Next, the shaping of the cut fibers will be explained.

A well-known fiber forming technique can be used to form the cut fibers. For example, when forming a nonwoven mat using only metal fibers, the cut fibers can be shaped into an appropriate shape using the dry method or wet method described above. In any case, as shown in FIG. 3, a twenty-one dollar punch 70 equipped with a large number of J-shaped needles 71 is inserted into and removed from the nonwoven mat 80 after the molding to separate the metal fibers. The tensile strength is reinforced by increasing the intertwining of the two.

In addition, when the cut fibers are attached to another nonwoven mat to form the nonwoven mat as a composite material, as shown in FIG.
, As shown in (b), metal fibers 90 are spread on a non-woven mat 100 made of glass fiber, for example, by a dry method or a wet method, and a twenty-one dollar punch 70 similar to the above is inserted into and removed from the non-woven mat 100 to form metal fibers. Non-woven mat 1 with 90 fibers
Just embed it in 00. Incidentally, during the molding, a binder may be added as appropriate to suppress separation of the cut fibers.

By the way, metal fibers obtained by cutting long brass fibers with a fiber diameter of 100μ■ into lengths of 30mm produced by the cutting device shown in Fig. 1(a) and metal fibers obtained by cutting using the conventional chatter vibration cutting method. The generated fiber diameter is approximately 100 μm, length is 30 ml.
Brass metal fibers of
A test piece with a length of 100 cm was obtained, and a tensile test was performed by clamping the longitudinal end of each test piece. The result was that the conventional product made using the chatter vibration cutting method tore at about 3 kg, whereas the present product It was confirmed that the invented product showed no tearing up to about 5 kg, and had nearly double the tensile strength.

(Effects of the Invention) As explained above, according to the present invention, a rotating shaft on which a thin metal strip material is wound many times is rotated in a direction opposite to the winding direction, and the end face of the wound material is rotated. By cutting with a cutting blade, long fibers with fiber diameters corresponding to the wall thickness can be continuously produced from metal materials of various strengths wound around a rotating shaft. By cutting the fibers appropriately, the fibers are curled three-dimensionally and have a rough surface.
In addition, since metal fibers with appropriate toughness can be produced, by forming the metal fibers into an appropriate shape, sufficient strength can be exerted through mutual bonding due to the intertwining of metal fibers, and there is no possibility that the fibers will fall off. Non-woven mats can be produced.

In addition, since the fiber production method described above makes it possible to produce long fibers with uniform fiber diameter with high efficiency,
Non-woven mats with stable quality can be mass-produced, and the manufacturing cost of non-woven mats can be significantly reduced.

[Brief explanation of the drawing]

1(a) to 1(c) show a cutting device according to the present invention, FIG. 1(a) is a side view of the cutting device, and FIG.
FIG. 1(b) is a partial enlarged view of FIG. 1(a), FIG. 1(c) is a partial perspective view of FIG. 1(a), and FIG. 2 is a simplified diagram of the laminated rolling apparatus according to the present invention. Figure 3 is an explanatory diagram of strength reinforcement of a non-woven mat, and a diagram of a manufacturing process of a non-woven mat made of a composite material. DESCRIPTION OF SYMBOLS 10... Main spindle, 20... Winding material, 20a... Parts of winding material, 51... Cutting blade, 80, 100...
Non-woven mat. Patent Applicant Nipex Co., Ltd. Akira Yanagisawa Agent Patent Attorney Yoshitaka Yoshida April 1990

Claims (1)

[Claims] A step of winding a thin metal strip-like material around the outer surface of a rotating shaft many times parallel to the axis of the rotating shaft, and rotating the rotating shaft in a direction opposite to the winding direction, Production of metal fibers for producing a non-woven mat, comprising: a step of cutting the end face of the wound material with a cutting blade to produce long fibers; and a step of appropriately cutting the long fibers. Method.