JP2002361590A - Cutting blade for fibers, fiber cutting device with such blade and glass-chopped strand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fiber cutting blade excellent in the shock resistance, which is free of breakage in its cutting edge even if a cutter roller is rotated at a high speed, involves very small wear of the blade part, and secures a large polishing margin in the case of reuse of worn blade upon polishing its cutting edge. SOLUTION: The cutting blade 1 for fibers consists of a blade part 1a formed from a plate-form cemented carbide composed of 90 mass% tungsten carbide (WC) with a mean particle size of 0.5 μm and 10 mass% cobalt (Co) and having a Vickers hardness of Hv. 1700 and a base part 1b formed from a plate-form carbon tool steel containing 98 mass% iron (Fe) and 0.8 mass% carbon (C), subjected to quenching and tempering, and having a Vickers hardness of Hv. 800. Acoording to one embodiment of the invention, the width L1 of blade part 1a is 5 mm while the width L2 of the base part 1b is 13 mm, the ratio being 2.6 to L1 .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting blade for fibers, and more particularly to a cutting blade suitable for cutting glass fibers to a predetermined length.

[0002]

2. Description of the Related Art In the production of glass fiber, molten glass is drawn out from a number of nozzles formed at the bottom of a bushing and spun as a continuous thin glass filament, which is cooled by a water spray, and a sizing agent is further added. The surface is coated, and several hundred to several thousand strands are bundled to form a glass strand, and the glass strand is wound by a winder to form a roving winding called a cake. The wound glass strand is used as a yarn through a twisting step or as a glass roving through a twining step, and is used as it is as a long fiber, and a glass chopped strand of a fixed length through a chopping step is used as FRTP or GRC (abbreviation for glass fiber reinforced cement)
Etc. are used.

[0003] In the above chopping step, a fiber cutting apparatus used for cutting a glass strand is generally a fiber cutting apparatus shown in FIG.
An apparatus as shown in FIG. The apparatus includes a cutter roller 2 having a plurality of cutting blades 1 radially attached at equal intervals, and a rubber roller 3 having rubber attached to an outer peripheral surface thereof. A glass strand G is provided between the cutter roller 2 and the rubber roller 3. Is cut into a predetermined length (for example, 1.5 to 12 mm).

Conventionally, as a cutting blade 1 to be attached to a cutter roller 2 of this type, quenching and tempering have been performed because of its excellent impact resistance. A carbon tool steel having a Vickers hardness of about 800 is generally used by polishing the end of the carbon tool steel and performing blade cutting. However, the cutting blade 1 made of such carbon tool steel is not cut because the blade part is worn with the lapse of use time. In particular, glass fibers are harder than organic fibers and the like, so the wear of the blade part is severe, and it is necessary to replace the cutting blade every few hours,
This has caused a reduction in production efficiency.

A cemented carbide has been conventionally known as a metal having excellent wear resistance. Cemented carbide has the advantage of being able to be reused by polishing even if worn, There is a disadvantage that it is inferior in terms of Therefore, when the cutter roller 2 is rotated at a high speed by a cutting device in which the cutting blade 1 made of a cemented carbide is attached to the cutter roller 2,
If an excessive impact load is applied to the cutting blade 1, there is a risk of breakage and scattering, so that the rotation of the cutter roller 2 must be slowed down, which has been an obstacle to improving the production efficiency.

In order to address the above problem, the present applicant has disclosed in Japanese Patent Application Laid-Open No. 11-123693 that the blade portion is formed from a cemented carbide and the base portion is formed from quenched and tempered carbon tool steel. There has been proposed a fiber cutting blade in which a blade portion and a base portion are joined via a nickel alloy layer.

As shown in FIG. 4, the above-mentioned fiber cutting blade has excellent wear resistance because the blade portion 1a is formed of a cemented carbide, and the base portion 1b has a hardened and tempered carbon. Since it is made of tool steel, it has excellent impact resistance, and the blade portion 1a because the base portion 1b absorbs vibration during fiber cutting.
Can be suppressed. Further, in this fiber cutting blade 1, the blade portion 1a and the base portion 1b are formed by a nickel alloy layer 1c.
And this nickel alloy layer 1c is
Nickel is dissolved in carbon tool steel and cemented carbide, and has a thermal expansion coefficient close to that of the cemented carbide as the material of the blade 1a, so that the blade 1a and the base 1b This has the advantage that the residual stress at the joint portion with the base member is reduced, and high strength can be realized without deformation of the joint portion.

[0008]

However, even if the blade portion 1a is made of cemented carbide and the base portion 1b is a cutting blade made of carbon tool steel, the cutter roller is rotated at high speed (for example, over 500 m). / Min), the base portion could not sufficiently absorb the vibration, and the cutting edge was broken and scattered.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to prevent the blade edge from being broken even when the cutter roller is rotated at a high speed, and to reduce the wear of the blade portion. An object of the present invention is to provide a fiber cutting blade which has a large polishing allowance when polishing and reusing the cutting edge of the blade portion, and which has excellent impact resistance.

[0010]

According to the present invention, there is provided a fiber cutting blade comprising a blade portion made of cemented carbide and a base portion made of carbon tool steel joined to each other. It is characterized in that the length is configured to be 2 to 5 times the length from the joint end of the blade portion to the cutting edge.

[0011] The fiber cutting device 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 an outer peripheral surface fitted with rubber. However, the blade portion made of cemented carbide and the base portion made of carbon tool steel are joined, and the length from the joining end to the other end of the base portion is the length from the joining end of the blade portion to the cutting edge. It is characterized by being configured to be 2 to 5 times.

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 mounted at equal intervals; and a rubber roller having an outer peripheral surface fitted with rubber. However, the blade portion made of cemented carbide and the base portion made of carbon tool steel are joined, and the length from the joining end to the other end of the base portion is the length from the joining end of the blade portion to the cutting edge. It is characterized by being produced by a fiber cutting device configured to be 2 to 5 times.

In the present invention, the length (width of the base portion) L ₂ from the joining end to the other end of the base portion is equal to the length (width of the cutting portion) L ₁ from the joining end of the blade portion to the cutting edge. why configured so as to be 5 times the width L ₂ of the base portion is less than twice the width L ₁ of the blade, sufficiently absorb body portion when the cutter roller is rotated at a high speed is a vibration This is because the blade portion is easily broken due to an excessive impact load applied to the blade portion. On the other hand, the width L _{2 of the} base portion is equal to the width L _{1 of the} blade portion.
If it is more than 5 times, the width of the blade portion becomes relatively short due to the limitation due to the mounting dimensions of the fiber cutting blade. As a result, when the worn edge of the blade portion is polished and reused in order to restore the cutting performance of the cutting blade, the number of times of polishing is limited because the amount of polishing is small, and the life is shortened. In the present invention, the width L ₂ of the base portion is preferably a 2.1 to 4 times the width L ₁ of the blade, and more preferably further 2.2 to 3 times.

As the cemented carbide for forming the blade portion of the present invention, an extremely hard alloy obtained by mixing and sintering a metal element carbide powder and a metal powder can be used. It can be reused by polishing if worn. Specifically, WC-Co type, WC-TaC-
Co-based, WC-TiC-Co-based, WC-TiC-TaC
-Co-based alloys can be used, and the thermal expansion coefficients of these alloys are 48 to 62 × 10 in a temperature range of 25 to 200 ° C.
^-7 / ° C.

The carbon tool steel forming the base portion of the present invention is obtained by quenching and tempering carbon-containing iron, and SK-5 and SK-2 can be used. 100 to 12 in the temperature range of 25 to 200 ° C
0 × 10 ⁻⁷ / ° C.

In the present invention, it is preferable that the blade portion and the base portion are joined via a nickel alloy layer or a cobalt alloy layer. That is, when nickel or cobalt is arranged between the blade portion and the base portion, and this is welded, nickel and cobalt dissolve into carbon tool steel and cemented carbide and are integrated. In particular, the nickel alloy layer is suitable because it has a thermal expansion coefficient close to the thermal expansion coefficient of a cemented carbide, so that a residual stress hardly occurs, the material cost is low, and the workability is excellent.

The thickness of the fiber cutting blade of the present invention is from 0.3 to
It is preferably 4.5 mm. The thickness of the cutting point is 0.
If it 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 3.0 of the Vickers hardness of the base portion.
It is desirable to configure so as to be 0 times. The reason is that if the Vickers hardness of the blade portion is less than 2.0 times the Vickers hardness of the base portion, the entire cutting blade tends to be excessively deformed (sticky) when cutting the fiber, and the rubber roller has been particularly worn. In this case, the blade edge does not accurately hit the fiber, and erroneous cutting (miscutting) is likely to occur. Conversely, if it exceeds 3.0 times, the difference in thermal expansion coefficient between the blade portion and the base portion increases. This is because it is difficult to perform stable bonding.

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

First, the blade has an average particle size of 0.5 to
85-95% by weight of tungsten carbide (WC) powder at 1.0 [mu] m and 5-15% by weight of cobalt (Co)
A cemented carbide formed into a predetermined size and shape (for example, a width of 3 to 7 mm) by mixing and sintering a powder, and 0.8 to 1.3% 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 20 mm) by quenching and tempering iron (Fe) to be prepared. Next, a nickel foil (thickness: 0.2 to 0.5 mm) is aligned with the tip of the base portion made of carbon tool steel, and the rear end of the blade portion made of cemented carbide is placed on the tip of the base portion aligned with the nickel foil. After the alignment, the nickel foil is irradiated with a laser and heated. Thereby, the nickel, the carbon tool steel and the cemented carbide are locally heated to form a nickel alloy layer, and the blade portion and the base portion are joined by the nickel alloy layer. This nickel alloy layer (coefficient of thermal expansion is 30
(40 to 47 × 10 ^-7 / ° C in the temperature range of to 300 ° C)
Is a material in which nickel is dissolved in carbon tool steel and cemented carbide, and a cemented carbide as a material of the blade portion (thermal expansion coefficient: 48 to 62 × 10 in a temperature range of 25 to 200 ° C.)
^-7 / ° C), the thermal stress remaining at the joint between the blade and the base is small, and the blade and the base are firmly connected without deforming the joint. Joined. After joining the blade portion and the base portion in this manner, a cutting blade for a fiber is obtained by subjecting the tip of the blade portion to blade processing. Incidentally, the joining of the base portion and the blade portion can be performed by coating the front end of the base portion by spraying nickel, aligning the rear end of the blade portion, and irradiating a laser,
It is preferable to use a nickel foil because a stable nickel alloy layer can be obtained. It is also possible to coat the blade portion and the base portion by coating with cobalt instead of nickel and irradiating with laser.

The fiber cutting apparatus of the present invention is suitable for cutting hard fibers such as glass fibers because the wear of the blade portion is small. However, since the vibration is sufficiently absorbed, the cutting edge is less likely to break, and the productivity of the glass chopped strand can be greatly improved.

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

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a fiber cutting blade according to 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, wherein (A) is a front view, and (B) is a YY line of (A).
It is a line sectional view.

The fiber cutting blade 1 has an average particle size of 0.5 μm.
90% by mass of tungsten carbide (WC)
0% by mass of cobalt (Co), and the Vickers hardness Hv1 is Hv. 1700 plate-shaped cemented carbide (25
Thermal expansion coefficient 57 × 10 ^-7 /
° C) and 98% by mass of iron (F
e) and 0.8% by mass of carbon (C), and the quenched and tempered Vickers hardness Hv2 is Hv. And a base portion 1b formed of a plate-shaped carbon tool steel of 800 (SK-5: 112.5 × 10 ⁻⁷ / ° C. in a temperature range of 20 to 200 ° C.). The blade portion 1a and the base portion 1b are joined via a nickel alloy layer 1c (coefficient of thermal expansion in a temperature range of 30 to 300 ° C. 40 to 47 × 10 ⁻⁷ / ° C.). In addition, the blade portion 1a of the fiber cutting blade 1
Width L ₁ of 5 mm, the width L ₂ of the base portion 1b is 13 mm, L ₂ is 2.6 times that of L _1.

The above-described fiber cutting blade 1 was manufactured as follows.

First, as shown in FIG. 2A, after fine particles of tungsten carbide (WC) containing Co as a binder are fired, HIP (Hot Isostatic) is fired.
sPress) to produce a blade-shaped blade member 1a 'made of a cemented carbide. Further, a quenched and tempered carbon tool steel was produced, and processed according to the end face shape of the blade member 1a 'to produce a base 1b.

Next, as shown in FIG.
b, a nickel foil N having a thickness of about 0.3 mm is aligned near the tip of the base member 1b, and the rear end of the blade member 1a 'is aligned with the tip of the base portion 1b aligned with the nickel foil N. Was irradiated with a YAG laser. This YAG laser irradiation heats the nickel foil N and the base 1b, and FIG.
As shown in (C), nickel mainly forms a solid solution in iron, which is a component of carbon tool steel, and at the same time dissolves in a cemented carbide, thereby forming a nickel alloy layer 1c '.

After joining the blade member 1a 'and the base portion 1b in this way, as shown in FIG. 2D, the blade portion 1a' and the base portion 1b are subjected to a cutting process so that the tip of the blade member 1a 'is subjected to cutting.
b formed the fiber cutting blade 1 joined via the nickel alloy layer 1c.

A plurality of the cutting blades 1 thus obtained were radially mounted around the cutter roller 2 at equal intervals as shown in FIG. 3 to obtain a fiber cutting device. Using this fiber cutting device, the cutter roller 2 was rotated at a peripheral speed of 500 m / min, and the glass strand G was cut to a length of 3 mm. It could be used without any problems. Thereafter, the blade edge of the blade portion 1a was polished and reused. However, even if the polishing and reuse were repeated five times, there was enough room for the polishing allowance of the blade portion 1a, and simultaneous repetitive use was possible. .

On the other hand, as comparative examples, cutting blades were manufactured under the same conditions except that the width L ₁ of the blade portion 1a was 4.0 mm and the width L ₂ of the base portion 1b was 7.0 mm. When the glass strand G was cut under the same conditions as above using the cutter roller 2 to which a plurality of these were attached, breakage occurred in the blade portion of the cutting blade in about 30 hours.

As another comparative example, the width L ₁ of the blade 1a is set.
The 3.0 mm, except that the width L ₂ of the base portion 1b was 15.6 mm, to prepare all the cutting blade in the same conditions, using a cutter roller 2 attached plurality this glass under the same conditions as above When the strand G was cut, when about 50 hours had passed, the blade 1 was used to restore cutting performance.
a was polished and reused. However, when this polishing was repeated three times, the polishing allowance of the blade portion 1a became small, and further polishing and reuse were impossible.

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

[0034]

As described above, the cutting blade for fiber of the present invention is radially attached to the cutter roller, and the blade portion breaks because the base portion absorbs vibration even when the cutter roller is rotated at high speed. It is hard to wear, and the wear of the blade part is small, and a sufficient polishing allowance is secured in the blade part, so the life can be extended by polishing the blade part, and it is possible to significantly improve production efficiency. is there.

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 the drawings]

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

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

FIG. 3 is a schematic diagram illustrating a main part of a fiber cutting device.

FIG. 4 is a schematic sectional view showing a conventional fiber cutting blade.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cutting blade for textiles 1a Blade part 1b Base part 1c Nickel alloy layer 2 Cutter roller 3 Rubber roller G Strand N Nickel foil L ₁ Length from joint end of blade part to blade tip (width of blade part) L ₂ Bonding of base part Length from end to end (width of base)

Claims (4)

[Claims] An edge portion made of cemented carbide and a base portion made of carbon tool steel are joined, and the length from the joining end of the base portion to the other end is from the joining end of the cutting portion to the cutting edge. Length 2
A fiber cutting blade, characterized in that the cutting blade is configured to be five times larger. 2. The fiber cutting blade according to claim 1, wherein the blade portion and the base portion are joined via a nickel alloy layer or a cobalt alloy layer. 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 a cemented carbide. The blade portion and the base portion made of carbon tool steel are joined, and the length from the joining end to the other end of the base portion is 2 to 5 times the length from the joining end of the blade portion to the cutting edge. A fiber cutting device characterized by being constituted. 4. A glass chopped strand produced by the fiber cutting device according to claim 3.