JP2003266370A - Fiber cutting blade, fiber cutting device using the same, and glass chopped strand - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fiber cutting blade that allows an edge part and a base part to stably join even when hardness of cemented carbide used as the edge part is increased, with excellent productivity owing to very low abrasion of the edge part, and excellent impact resistance. <P>SOLUTION: This fiber cutting blade 1 comprises an edge part 1a formed of a plate of the cemented carbide consisting of 95 mass % of tungsten carbide (WC) with a mean particle size of 0.5 μm and 5 mass % of cobalt (Co) and having a Vickers hardness of Hv. 2050, and a base part 1b formed of a plate of carbon tool steel (SK-5) including 98 mass % of iron (Fe) and 2 mass % of carbon (C), subjected to quenching and tempering, and having a Vickers hardness of Hv. 800. The edge part 1a and the base part 1b are joined through a cobalt alloy layer. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fiber cutting blade, and more particularly to a cutting blade suitable for cutting glass fibers into a certain length.

[0002]

2. Description of the Related Art In the production of glass fibers, molten glass is drawn out from a large number of nozzles formed at the bottom of a bushing, spun into continuous thin glass filaments, cooled with a water spray, and a sizing agent is added. The surface is coated and hundreds to thousands are bundled to form a glass strand, which is wound with a winder to form a roving roll called a cake. The wound glass strand is used as a yarn after a twisting process or as a glass roving after a compounding process, and is used as a long fiber, or as a glass chopped strand of a certain length after a chopping process such as FRTP or GRC (abbreviation for glass fiber reinforced cement)
It is used for etc.

A fiber cutting device used for cutting glass strands in the chopping process is generally shown in FIG.
An apparatus as shown in (A) is used. This device includes a cutter roller 2 in which a plurality of cutting blades 1 are radially attached at equal intervals, and a rubber roller 3 in which rubber is attached to the outer peripheral surface.
The glass strand G is fed between the cutter roller 2 and the rubber roller 3 to cut the glass strand G into a predetermined length (for example, 1.5 to 12 mm).

Conventionally, the cutting blade 1 attached to the cutter roller 2 of this type has been hardened and tempered by being hardened and tempered because of its excellent impact resistance. Generally, a carbon tool steel having a Vickers hardness of about 800 and having a blade processed at its tip is generally used. However, the cutting blade 1 made of such carbon tool steel becomes worn and the blade portion becomes uncut with the lapse of use time. In particular, glass fiber is harder than organic fiber and the like, so that the blade portion is heavily worn, and the cutting blade needs to be replaced every several hours, which causes a decrease in production efficiency.

Further, cemented carbide has been known as a metal having excellent abrasion resistance, and cemented carbide has an advantage that it can be reused by polishing even if it is worn, but it has impact resistance. There is a drawback in that it is inferior. Therefore, when the cutter roller 2 is rotated at a high speed with a cutting device in which the cutting blade 1 made of cemented carbide is attached to the cutter roller 2,
If an excessive impact load is applied to the cutting blade 1, the cutting blade 1 may be broken and scattered, so that the rotation of the cutter roller 2 has to be slowed, which is an obstacle to improvement of production efficiency.

In order to solve the above-mentioned problems, the applicant of the present invention has disclosed in Japanese Unexamined Patent Publication No. 11-123693 that the blade portion is made of cemented carbide and the base portion is made of quenching and tempered carbon tool steel. It proposes a fiber cutting blade in which a blade portion and a base portion are joined via a nickel alloy layer.

As shown in FIG. 3 (B), the fiber cutting blade described above has excellent wear resistance because the blade portion 1a is formed of cemented carbide, and the base portion 1b is hardened and tempered. Since it is formed of the applied carbon tool steel, it has excellent impact resistance, and since the base portion 1b absorbs vibrations when the fiber is cut, breakage of the blade portion 1a can be suppressed. Further, in the fiber cutting blade 1, the blade portion 1a and the base portion 1b are joined together via the nickel alloy layer 1c.
c is nickel dissolved in carbon tool steel and cemented carbide, and has a coefficient of thermal expansion similar to that of cemented carbide that is the material of the blade 1a. The residual stress of the joint portion with the base portion 1b is reduced, and the joint portion is not deformed and high strength can be realized.

[0008]

When the glass fiber is cut by the above cutting blade, it can be used for 40 to 50 hours, but it can be replaced for a longer time to improve productivity. Unnecessary cutting blades are required, and for that purpose it is necessary to improve the wear resistance of the cutting blades.

However, if the hardness of the cemented carbide as the material is increased in order to improve the wear resistance of the blade portion 1a of the cutting blade, the blade portion and the base portion cannot be stably joined (welded), and especially the Vickers hardness. Is Hv. If a cemented carbide of 2000 or more is used, it becomes very difficult to join the blade portion and the base portion.

The present invention has been made in view of the above problems, and an object thereof is to stabilize the blade portion and the base portion even if the hardness of the cemented carbide used as the blade portion is increased. The present invention is to provide a fiber cutting blade which is excellent in productivity and shock resistance because it can be joined together and the blade portion has very little wear.

[0011]

The fiber cutting blade of the present invention comprises a blade portion made of cemented carbide and a base portion made of carbon tool steel, and the blade portion and the base portion have a cobalt alloy layer. It is characterized by being joined through.

Further, the fiber cutting device of the present invention is a fiber cutting device comprising a cutter roller having a plurality of cutting blades mounted radially at equal intervals, and a rubber roller having rubber attached to the outer peripheral surface thereof. However, it is characterized in that it is provided with a blade portion made of cemented carbide and a base portion made of carbon tool steel, and the blade portion and the base portion are joined via a cobalt alloy layer.

Further, the glass chopped strand of the present invention is a fiber cutting device comprising a cutter roller having a plurality of cutting blades radially attached at equal intervals, and a rubber roller having rubber attached to an outer peripheral surface thereof. However, it is characterized in that it is provided with a blade portion made of cemented carbide and a base portion made of carbon tool steel, and the blade portion and the base portion are joined via a cobalt alloy layer.

As the cemented carbide for forming the blade of the present invention, an extremely hard alloy prepared by mixing a powder of a metal element carbide and a powder of a metal and sintering the mixture can be used. Generally, WC-Co is used.
System, WC-TaC-Co system, WC-TiC-Co system, W
C-TiC-TaC-Co based alloys are widely known, and the thermal expansion coefficient of these alloys is 48 to 62 x 10 ^-7 / ° C in the temperature range of 25 to 200 ° C.

The reason why the blade portion and the base portion can be stably joined in the present invention is that the cemented carbide contains Co (cobalt), and the blade portion and the base portion are joined via the cobalt alloy layer. Then, it is considered that the cobalt component in the blade portion reacts with the cobalt alloy layer to improve the compatibility between the two. Therefore, in the present invention, as the material of the blade portion, the Vickers hardness is Hv. Even if you use 2000 or more cemented carbide,
The blade portion and the base portion can be joined stably.

The carbon tool steel forming the base portion of the present invention is iron containing carbon that has been quenched and tempered. SK-5, SK-2, etc. can be used, and the thermal expansion coefficient of these is 100 to 12 in the temperature range of 25 to 200 ° C
It is 0 × 10 ⁻⁷ / ° C.

In the present invention, the blade portion and the base portion are joined via the cobalt alloy layer. When cobalt is arranged between the blade portion and the base portion and welded, the cobalt melts into the carbon tool steel and the cemented carbide and is integrated.

The thickness of the fiber cutting blade of the present invention is 0.3 to
It is preferably 4.5 mm. The thickness of the cut end is 0.
If the thickness is less than 3 mm, the strength is reduced, and if the thickness of the cutting blade exceeds 4.5 mm, it becomes difficult to shorten the fiber cutting length.

Further, in the fiber cutting blade of the present invention, the Vickers hardness of the blade portion is 2.0 to 3.
It is desirable to configure so that it becomes 0 times. The reason is that when the Vickers hardness of the blade portion is less than 2.0 times the Vickers hardness of the base portion, the entire cutting blade is likely to be excessively deformed (sticky) when the fiber is cut, and especially when the rubber roller is worn. In addition, the cutting edge does not hit the fiber accurately, and erroneous cutting (miscut) is likely to occur, conversely 3.0
This is because if it exceeds twice, the difference in thermal expansion coefficient between the two becomes large, and stable bonding becomes difficult.

Further, in the fiber cutting blade of the present invention, the length L ₂ from the joint end of the base portion to the other end (width of the base portion) is the length from the joint end of the blade portion to that of the blade tip (of the blade portion). Width) 2 to 5 of L ₁
It is desirable to configure so as to double. The reason is,
When the width L _{2 of the} base portion is less than twice the width L ₁ of the blade portion, it is difficult for the base portion to sufficiently absorb the vibration when the cutter roller is rotated at a high speed, which is more than 5 times. Then, the width of the blade portion becomes relatively short, the number of times of polishing when the blade edge is polished and reused is limited, and the life becomes short.

Next, a method for producing the fiber cutting blade of the present invention will be described.

First, the blade portion has an average particle size of 0.5 to
88-96 mass% tungsten carbide (WC) powder at 0.7 μm and 4-12 mass% cobalt (Co)
Cemented carbide formed into a predetermined size and shape (for example, width 3 to 6 mm) by mixing powder and sintering, and iron (Fe) containing 2% by mass of carbon (C) as a base portion.
A carbon tool steel formed into a predetermined shape (for example, a width of 12 to 17 mm) by quenching and tempering is prepared. Next, a cobalt foil (thickness: 0.2 to 0.5 mm) is aligned with the tip of the base body made of carbon tool steel, and the rear end of the blade made of cemented carbide is aligned with the tip of the base body aligned with the cobalt foil. After alignment, the cobalt foil is irradiated with a laser.
Thereby, cobalt, carbon tool steel, and cemented carbide are locally heated to form a cobalt alloy layer, and the cobalt alloy layer joins the blade portion and the base portion. Further, at this time, the cobalt component in the cemented carbide reacts with the cobalt alloy layer, the compatibility between the two is improved, and stable welding is performed. After joining the blade portion and the base portion in this manner, a cutting blade for fibers is obtained by subjecting the tip of the blade portion to blade processing. still,
It is also possible to join the base part and the blade part by spraying cobalt on the tip of the base part and coating it, then aligning the rear end of the blade part and irradiating with a laser, but using a cobalt foil. It is preferable to do so because a stable cobalt alloy layer can be obtained.

Further, the fiber cutting device of the present invention is suitable for cutting hard fibers such as glass fibers because the blade portion is less worn, and this device is effective even when the cutter roller is rotated at a high speed. Since it sufficiently absorbs vibration, the cutting edge is less likely to break, and the productivity of glass chopped strands can be significantly improved.

In the fiber cutting device of the present invention, when the cutting blades are arranged at a short distance (for example, at an interval of 3 mm), the cutting blades may come into contact with each other and are gradually worn and damaged. Rubber on both sides (eg 0.2-0.5m thick)
It is preferable to attach a buffer material such as m) or a metal spacer because the cutting blade is less likely to be damaged.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the fiber cutting blade of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an explanatory view showing a fiber cutting blade of the present invention, in which (A) is a front view and (B) is YY of (A).
It is a line sectional view.

The fiber cutting blade 1 has an average particle size of 0.5 μm.
95% by mass of tungsten carbide (WC)
It is composed of cobalt (Co) in mass% and has a Vickers hardness of Hv. A blade portion 1a made of a plate-shaped cemented carbide of 2050, 98% by mass of iron (Fe) and 2% by mass of carbon (C), hardened and tempered, and having a Vickers hardness of Hv ． 800 plate-shaped carbon tool steel (SK-
5) and the base portion 1b formed by 5). The blade portion 1a and the base portion 1b are joined via the cobalt alloy layer 1d. The blade portion 1a has a length L ₁ (width) of 5 mm, and the base portion 1b has a length L ₂ (width) of 13 mm.

The fiber cutting blade 1 is manufactured as follows.

First, as shown in FIG. 2A, fine particles of tungsten carbide (WC) containing Co as a binder are fired, and then HIP (Hot Isostatic).
sPress) treatment to produce a blade member 1a ′ made of a plate-shaped cemented carbide. Further, a carbon tool steel that was hardened and tempered was manufactured, and processed according to the end surface shape of the blade member 1a 'to manufacture the base portion 1b.

Next, as shown in FIG. 2B, the base portion 1
Cobalt foil C having a thickness of about 0.3 mm is aligned near the tip of b, and the rear end of blade member 1a ′ is aligned with the tip of base portion 1b aligned with cobalt foil C. Was irradiated with a YAG laser. The irradiation of the YAG laser heats the cobalt foil C, the base portion 1b, and the blade member 1a ', so that cobalt dissolves in iron, which is a component of the carbon tool steel, as shown in FIG. The cobalt alloy layer 1d ′ is formed by melting into the hard alloy. After joining the blade member 1a ′ and the base portion 1b in this way,
As shown in FIG. 2 (D), a cutting blade 1 for fibers in which the blade portion 1a and the base portion 1b are joined via the cobalt alloy layer 1d is formed by subjecting the tip end of the blade member 1a 'to blade processing. did.

A plurality of the cutting blades 1 thus obtained are radially attached to the periphery of the cutter roller 2 at equal intervals as shown in FIG.

Using such a fiber cutting device, the cutter roller 2 was rotated at a peripheral speed of 500 m / min to cut the glass strand G into a length of 3 mm.
Even after a lapse of time, no breakage was observed in the blade portion 1a and the blade portion 1a could be used without any problem. After that, the blade edge of the blade portion 1a was polished and reused.
The polishing allowance of a was sufficiently large, and repeated use at the same time was possible.

On the other hand, as a comparative example, cutting blades were produced under the same conditions except that nickel foil was used instead of cobalt foil, and a plurality of cutter blades 2 were used to carry out the above-mentioned cutting. Glass strand G under the same conditions as
When was cut, the blade portion of the cutting blade was broken in about 30 hours.

In this embodiment, an example in which glass fiber is cut is given, but the present invention is not limited to this and can be applied to various other fibers such as aramid fiber and carbon fiber. Needless to say. The Vickers hardness in the present invention is measured according to JIS Z2251.

[0035]

As described above, in the fiber cutting blade of the present invention, the blade portion and the base portion can be stably joined even if cemented carbide having a very high hardness is used as the material of the blade portion. It can be attached to the cutter roller in a radial manner, and even if the cutter roller is rotated at a high speed, the base part absorbs vibrations, so the blade part is less likely to break, and the blade part is less likely to wear and Since the polishing allowance is secured, the life can be extended by polishing the blade portion, and it is possible to significantly improve the production efficiency.

Further, the fiber cutting apparatus of the present invention is suitable for cutting hard fibers such as glass fibers because the blade portion of the cutting blade is less worn, and can greatly improve the productivity of glass chopped strands. it can.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a fiber cutting blade of the present invention,
(A) is a front view and (B) is a sectional view taken along line YY of (A).

FIG. 2 is an explanatory view showing a process of producing a fiber cutting blade of the present invention.

FIG. 3 is a schematic explanatory view of a main part showing a fiber cutting device.

[Explanation of symbols]

1 Fiber cutting blade 1a blade 1b Base part 1c Nickel alloy layer 1d cobalt alloy layer 2 cutter roller 3 rubber roller G Strand C cobalt foil

Claims (4)

[Claims] 1. A fiber, comprising a blade portion made of cemented carbide and a base portion made of carbon tool steel, wherein the blade portion and the base portion are joined via a cobalt alloy layer. Cutting blade. 2. The blade has a Vickers hardness of Hv. 200
The fiber cutting blade according to claim 1, wherein the fiber cutting blade is made of 0 or more cemented carbide. 3. A fiber cutting device comprising a cutter roller having a plurality of cutting blades radially attached at equal intervals, and a rubber roller having rubber attached to an outer peripheral surface thereof, wherein the cutting blade is made of cemented carbide. A fiber cutting device comprising a blade portion and a base portion made of carbon tool steel, wherein the blade portion and the base portion are joined via a cobalt alloy layer. 4. A glass chopped strand produced by the fiber cutting device according to claim 3.