JPH0550965B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is a method for converting aggregates of short fibers such as carbon and aramid fibers in the state of factory-produced raw materials into individual short fibers in a dry state. A method for uniformly and continuously mixing the short fibers with submicron fine powder such as silica fume, or fine fibers of about the same diameter, or powders such as cement and refractories together with them, while dispersing them in a filament shape, and Regarding equipment.

(Prior art) The present applicant previously developed a device (Japanese Patent Publication No. 1983-1983-1) for dispersing small pieces or chop-shaped short fibers of short carbon fibers one by one.
(see Publication No. 58886). Then, the short carbon fibers dispersed by this fiber dispersion device are uniformly dispersed and mixed into the raw materials for molded products such as cement and refractories, and the carbon fiber single fibers, which tend to aggregate easily, come into contact with each other during dispersion and mixing. In order to prevent agglomeration from occurring. Submicron fine powder such as silica fume with a particle size of about 0.1μ to 1μ or fine fibers of about the same diameter are adsorbed onto the surface of each monofilament and interposed between each fiber to prevent agglomeration. The above manufacturing method includes mixing the dry short carbon fiber raw material and the above-mentioned molded product raw material powder. While carbon short fiber small lumps or chop-shaped short fibers are dispersed into individual short carbon fibers, submicron fine powder such as silica hume with a particle size of about 0.1μ to 1μ or fine fibers with the same diameter are atomized. The short carbon fibers are sequentially introduced into a mixer where they are dispersed, and subjected to agglomeration prevention treatment characterized by adsorbing and intervening submicron fine powder or fine fibers of approximately the same diameter on the surface of each short carbon monofilament. A method for producing dry short carbon fiber raw material. ．． While dispersing carbon short fiber small lumps or choppy short fibers one by one into individual short carbon fibers, submicron fine powder such as silica hume with a particle size of about 0.1μ to 1μ or fine fibers with about the same diameter are added to each of the above. A method for producing a dry carbon short fiber raw material subjected to an agglomeration prevention treatment characterized by successively spraying onto the surface of a monofilament of carbon short fibers, adsorbing the fibers, and interposing them between each fiber. ．． At the same time as the fibers are dispersed, each short carbon fiber is mixed with a submicron fine powder such as silica hume with a particle size of about 0.1μ to 1μ or a fine fiber with the same diameter. We proposed a method for producing dry carbon short fiber raw material that has been subjected to agglomeration prevention treatment, which is characterized by adsorbing submicron fine powder or fine fibers of about the same diameter on the surface of each monofilament. . Furthermore, the above-mentioned patent publication No. 62-
As a method and means for solving the problems of the fiber dispersion device shown in Publication No. 58886. Aggregates of short fibers are forcibly fed approximately toward the center of a rotating body that has many small protrusions on its surface through a pair of transfer devices such as belt conveyors, and the aggregates held in place at the tip of the transfer device are A method for dispersing aggregates of short fibers into single fibers, which are scraped off by a large number of small protrusions on the surface of a rotating body and dispersed into single fibers. ．． A transfer device such as a pair of belt conveyors is disposed approximately toward the center of a rotating body having a large number of small protrusions, and a device for supplying aggregates of short fibers to the transfer device is provided. We have proposed an apparatus for dispersing short fiber aggregates into single fibers, which is equipped with a means for holding the aggregates forcedly transferred at the same time as sending them out.

(Problems to be Solved by the Invention) However, in the above-mentioned prior art, even if dry carbon short fiber raw materials are produced after being subjected to agglomeration prevention treatment using the method and apparatus described above, cement, refractories, etc. In order to uniformly disperse and mix the raw materials for molded products, when putting them into a mixer and stirring them, (1) the fiber diameter is relatively small and the specific volume per unit is bulky; (2) the fibers When the diameter is relatively long and the specific volume per unit is bulky (3) When the amount of fiber mixed in is large compared to the raw material of the molded product, short fibers tend to granulate due to rotational motion. Therefore, there was a risk that problems would arise in dispersion. In order to clear this condition,
It is possible to make some adjustment by increasing the amount of submicron fine powder such as silica hume or fine fibers added, but the amount of these fine powders etc. Compared to the raw material, exceeding the original limit causes effects such as a decrease in strength, which inevitably necessitates certain restrictions. However, depending on the method, there was a concern about the tendency of granulation due to the above-mentioned mixing. In addition, since dry short carbon fibers and raw materials for molded products such as cement or refractories are mixed in a mixer, it is necessary to use a batch method according to the capacity of the mixer. There is no argument that the manufacturing method is superior.

(Means for Solving the Problems) The present invention aims to solve the various problems mentioned above, and aims to pass short fiber aggregates between a pair of transfer devices such as a belt conveyor using the raw material quantitative supply device. A fixed amount of water is continuously forcibly fed toward the approximate center of a first rotating body having a large number of small protrusions on its surface, and the aggregates held by the tip of the transfer device are scraped off by the large number of small protrusions on the surface of the rotating body. They are dispersed in a filament shape, and are diffused and mixed in a passageway that widens toward the tip in the direction of rotation according to the strong air flow generated by the high-speed rotation of the first rotating body. The powder is sprayed onto the surface of the second rotating body having small protrusions, and the powder is sprayed onto the surface of the second rotating body, and the powder is sprayed onto the surface of the second rotating body.
A method of continuously mixing monofilament-shaped short fibers and powder by continuously supplying a fixed amount onto the surface of a second rotating body and scattering the powder according to the air flow generated by the high speed rotation of a second rotating body. A transfer device such as a pair of belt conveyors is disposed approximately toward the center of a first rotating body having a large number of small protrusions, and aggregates of short fibers are continuously and quantitatively fed between the transfer devices by the raw material quantitative supply device. a feeding device, a means for feeding the aggregates forcibly transferred at the tip of the transfer device while being pinched and held, and a passageway extending toward the tip in the rotational direction of the rotating body. A second rotary body with a large number of small protrusions on the surface is installed in front of the expanded body, and a powder metering device capable of continuously supplying powder at a fixed rate is installed on the top of the second rotating body. The invention is characterized by an apparatus that continuously mixes the short fibers and the powder together with the short fibers.

(Function) The present invention continuously forcibly supplies short fiber aggregates of about 3 to 25 mm between a pair of transfer devices such as a belt conveyor by a fixed amount supply device installed at the bottom of the raw material storage hopper. While holding the aggregate at the tip, it is scraped off by a large number of small protrusions on the surface of the first rotating body and dispersed in a monofilament shape, and then sprayed onto the surface of the second rotating body. The powder metering device installed on the top of the body continuously supplies a fixed amount of inorganic fine powder such as silica fume with a particle size of about 0.1μ to 1μ or inorganic fine fibers such as asbestos tailings with a diameter of about 0.01μ to 1μ on the surface. supplied,
The short fibers are scattered by small protrusions on the rotating surface and are discharged to the rear while being continuously mixed with monofilament-shaped short fibers blown from the first rotating body. At this time, the transfer speed of the above-mentioned transfer device and the supply amount per unit time by the powder quantitative supply device can be adjusted respectively according to the target specifications, and in some cases, the above-mentioned fine powder, etc. It is also possible to continuously supply a fixed amount from the surface of the aggregate raw material transferred by the second rotating body, and to continuously charge the powder of the raw material for molded products such as cement or refractory from the powder fixed quantity supply device on the upper part of the second rotating body. A third rotary body of the same shape is installed in front of the second rotary body in the rotational direction, and the above-mentioned fine powder, etc. is continuously supplied from the upper part of the second rotary body, and powder of molded product raw material is continuously supplied from the upper part of the third rotary body. Alternatively, when there are a plurality of types of raw material powder, they may be mixed in advance and supplied. In this way, the short fiber aggregate becomes a monofilament, which is uniformly mixed with the fine powder and the molded product raw material powder, allowing continuous processing and manufacturing over a long period of time.

(Example) Hereinafter, a detailed explanation will be given based on the example shown in FIG. Reference numerals 1 and 14 denote first and second rotating drums each having a diameter of 400 mm and rotating in the direction of the arrow at 980 and 750 rpm, respectively, each having a large number of needle-like protrusions 2 and 15 protruding from their surfaces. 3 is an aggregate raw material of pitch-based short carbon fibers or aramid short fibers cut to about 3 to 25 mm; 4 is a hopper for storing the raw material; 5;
Reference numeral 5' denotes a pair of rotary members for quantitative supply of raw materials provided at the bottom of the hopper 4, each rotating in the direction of the arrow.
The mechanism is such that the supply amount can be increased or decreased by varying the rotational speed, and reference numeral 6 is a belt conveyor for transferring and supplying raw materials that is arranged approximately horizontally and moves in the direction of the arrow. 1, and a small gap is provided between the tip of the vertical portion 6' and the needle-like protrusion 2. 9
is movable in the direction of the arrow by a biting belt conveyor disposed approximately parallel to the vertical portion 6', and its tip guide roller 10 is moved by the vertical portion 6 of the belt conveyor 6 by a spring disposed on the side surface. 'It is constantly pressed toward the guide roller 11 at the tip. Reference numeral 12 denotes an auxiliary belt conveyor disposed horizontally above the guide roller 8 and movable in the direction of the arrow. Reference numeral 13 denotes a casing, which is wound along the rotational direction of the first rotating drum 1 from the tip of the vertical portion 6' of the belt conveyor 6, and has a structure in which the distance between the casing and the first rotating drum 1 gradually increases. Similarly, the lower part of the second rotating drum 14 can be slid vertically up and down to adjust the spacing. 16 is a hopper for powder, 17 is a particle size of 0.1μ to 1μ
Inorganic powder of silica hume or diameter 0.01μ
~1μ inorganic fine fibers with asbestos tailings,
Reference numeral 18 denotes a powder supply belt conveyor which is arranged horizontally below the powder hopper 16 so that it can be transferred in the direction of the arrow, and there is a slight distance between its upper surface and the lower part of the powder hopper 16. is provided, and the amount of powder can be increased or decreased by adjusting the gap.

19 is a cylindrical rotating drum for powder supply with a diameter of 150 mm;
It rotates at 250 rpm in the direction of the arrow, and its circumferential portion is provided with slits in the longitudinal direction to increase the frictional resistance with the powder falling from the end of the belt conveyor 18. It has a structure that allows easy supply to the needle-like protrusion 15 of.

Next, the effect will be explained. The raw material 3 is continuously supplied in a quantitative manner onto the raw material transfer and supply belt conveyor 6 from between the quantitative supply rotary members 5 and 5' installed at the lower part of the raw material storage hopper 4, and is pressed upward by the auxiliary belt conveyor 12. It is forcibly transferred between the vertical part 6' of the belt conveyor 6 and the biting belt conveyor 9 from above, and is sent out while being pinched and held by the guide rollers 10 and 11 at the tip. It is scraped off by the needle-like protrusions 2 of the rotating drum 1 and dispersed into monofilaments. Due to the strong air flow generated by the rotation of the first rotating drum 1, the dispersed single fibers pass through the gap between the casing 13 and the casing 13, which gradually expands in volume, and are further made into single fibers. While being promoted, the second rotating drum 14
The liquid is sprayed onto needle-like protrusions 15 protruding from the surface. At this time, since the circumferential speeds of the first and second rotating drums 1 and 14 are different, the formation of single fibers is further promoted, and the inorganic powder or inorganic fine particles that fall from the upper part of the second rotating drum and are scattered. It is uniformly and continuously mixed with the fibers 17 and discharged to the rear.
As described above, the supply amount of the short fiber aggregate raw material 3 by the rotating members 5, 5' for quantitative supply, the supply speed of the raw material supply belt conveyor 6, and the supply amount of the inorganic fine powder, etc. 17 are initially adjusted respectively based on the specifications. By doing this, it becomes possible to continuously process and manufacture a dry compound in which short fibers such as carbon and aramid are uniformly mixed at a high mixing rate in a dry state.

[An example of mixing with molded product raw materials]

1 (1) Pitch-based short carbon fiber (length 20mm)
3% (weight ratio) (2) Inorganic fine powder (silica hume, particle size 0.1μ ~
1μ) 9% (〃) (3) Cement 60% (〃) (4) Aggregate (carbon calcium powder) (particle size adjustment particle size 20μ to 200μ) 28% (〃) 2 (1) Pitch-based short carbon fiber ( length 3mm)
3.8% (weight ratio) (2) Aramid staple fiber (length 3mm)
3.8% (〃 ) (3) Inorganic fine fiber (asbestos tailing, diameter 0.01μ
~1μ) 15.4% (〃) (4) Phenol resin powder 7.0% (〃) (5) Calcium carbonate powder (particle size adjustment particle size 10μ~
120μ) 70.0% (〃) (Effects) The present invention uses aggregates of various short fibers such as carbon and aramid to form a large number of fine protrusions erected at small intervals on the cylindrical outer peripheral surface using the raw material quantitative supply device. A fixed amount is continuously supplied from any position on the surface of a first rotating body rotating in a constant direction onto a supply transfer device such as a belt conveyor installed toward the center of the rotating body, and a pair of belt conveyors etc. The raw material is forcibly fed through the feeding and transferring device, and while the raw material is firmly held at the tip of the feeding and transferring device, the agglomerate is turned into a monofilament by a movable member formed by fine protrusions on the surface of the first rotating body. The powder is sprayed on the surface of the second rotating body while being dispersed in a uniform manner, and is uniformly and continuously with the inorganic fine powder, inorganic fine fibers, cement, etc. raw material powder for molded products, which falls continuously in fixed amounts from the top of the rotating body and scatters. The gist of the present invention is a method and apparatus for dispersing an aggregate of short fibers into a monofilament shape, and at the same time uniformly and continuously mixing it with powder, so that the dispersion method and apparatus according to the prior art can be used. It has the following advantages compared to

(1) It is easy to produce dry short carbon fibers that have been treated to prevent agglomeration.

(2) Easy dry blending of short fiber aggregates and powders such as cement and refractories.

(3) Easy blending when a high proportion of short fibers is mixed, or when the fiber length is long and bulky.

(4) Unlike the conventional batch method, it is highly efficient because it can use a continuous processing method.

In addition, dry carbon and aramid carbon fiber raw materials subjected to agglomeration prevention treatment obtained by the method and apparatus of the present invention are used, and furthermore, these short fibers having a high mixing rate with powders such as cement and refractories are used. It is certain that the use of dry compounds in a wide range of fields will further promote the development of new materials with future potential, such as carbon and short aramid fibers.

[Brief explanation of the drawing]

FIG. 1 is a front view of one embodiment of the apparatus of the present invention. 1, 14...First rotating drum, second rotating drum, 2, 15... Needle-like protrusion, 3... Short fiber aggregate raw material, 4... Hopper for storing raw material, 5, 5'
... Rotating member for quantitative supply of raw materials, 6, 6' ... Belt conveyor for transferring and supplying raw materials, 7, 8, 1
0, 11... Guide roller, 9... Belt conveyor for biting, 12... Auxiliary belt conveyor,
13...Casing, 16...Hopper for storing powder, 17...Inorganic fine powder or inorganic fine fiber,
18... Belt conveyor for powder supply, 19...
Rotating drum for powder supply.

Claims (1)

[Scope of Claims] 1. The aggregate of short fibers is passed between a pair of belt conveyors or other transfer devices by the raw material quantitative supply device in a direction approximately toward the center of a first rotating body having a large number of small protrusions on its surface. The agglomerates held at the tip of the transfer device are scraped off by a large number of small protrusions on the surface of the rotary body and dispersed in a monofilament shape, using strong air generated by high-speed rotation of the first rotary body. According to the flow, the powder is diffused and mixed in a passage that widens toward the tip in the direction of rotation, and is sprayed onto the surface of a second rotating body that has many small protrusions on the surface installed in the front. A fixed amount of powder is continuously supplied to the surface of the second rotary body by a powder quantitative supply device disposed above the second rotary body, and the powder is dispersed according to the air flow generated by the high speed rotation of the second rotary body. A method of continuously mixing filament-shaped short fibers and powder. 2. A pair of transfer devices such as belt conveyors are arranged approximately toward the center of the first rotating body having a large number of small protrusions, and aggregates of short fibers are fixedly distributed between the transfer devices by the raw material quantitative supply device. a continuous supply device, a means for feeding out the aggregates forcibly transferred at the tip of the transfer device while being pinched and held; A second rotating body with a large number of small protrusions on the surface is installed in front of the passage to widen the passage, and a powder metering device capable of continuously supplying powder at a fixed rate is installed on top of the second rotating body. A device that continuously mixes the short fibers and powder by dispersing them into filaments.