JPH0325522B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is directed to the production of aggregates of short fibers in a dry state in the raw material state of various artificial fibers produced in factories, such as carbon short fibers and aramid short fibers. The present invention relates to a method and apparatus for uniformly dispersing into a single filament.

(Prior art) Conventionally, in order to disperse aggregates of entangled natural long fibers such as wool, cotton wool, jute, etc., each having a length of 1 inch to 3 inches, into single fibers in a dry state, it has been necessary for many years to disperse the aggregates as shown in Fig. 2. The device shown has been used. 1 is a cylindrical rotating drum with an outer diameter of 0.5 to 2 m and a length of about 0.8 to 2 m; 2 is a large number of needle-like protrusions protruding from its surface; 3 is a belt conveyor for supplying raw materials, with a pair at its tip. Biting rollers 4a and 4b are provided. 5 is a casing, and 6 is a raw material consisting of an aggregate in which the natural long fibers are entangled.

Next, the effect will be explained. First, the aggregated raw material 6 charged to the raw material supply device 3 is sent in the direction of the arrow to a pair of biting rollers 4a, 4b.
It gets caught in between. At the tip of the discharge port of the biting roller, there are many fine needle-like protrusions 2 on the outer peripheral surface.
A cylindrical rotating drum 1 with cylindrical rotating drums erected at small intervals.
The needle-like protrusion at the tip rotates at a speed of about 15 to 25 m/s in the direction of the arrow or in the opposite direction.
The raw material discharged while being strongly held by the biting rollers 4a and 4b is scraped and made into a single fiber, and the physical stress of the rotating drum 1 and the air flow generated by the rotation of the drum cause the needle-shaped protrusions 2 to form. and the casing 5 and is discharged rearward.
At this time, the gap between the casing 5 and the needle-like protrusion 2 is narrow in the part near the biting rollers 4a and 4b, and widens in the vicinity of the discharge part, so the scraped raw material rapidly expands in volume and becomes even more Single fiber formation is promoted. The discharged single fibers are then refined while being sequentially transferred to auxiliary mechanisms that work together according to each processing purpose, creating a mechanism that can achieve the initial purpose in a consistent and continuous work process. Furthermore, the needle-shaped protrusion 2 on the outer periphery of the rotating drum and the biting roller 4a,
4b, and the gap between the feeding device 3 and the biting roller 4.
Raw material supply speed and rotating drum 1 according to a and 4b
The circumferential speed is adjusted depending on the material of the raw material, the length and the purpose of processing, and consideration is given to avoid damage to the fibers during processing. Biting rollers 4a, 4b
is usually a round bar made of iron with striped slits in the longitudinal direction so that it can easily bite into and hold the raw material; 4a is fixed, and 4b is movable in the a ₁ - a ₂ direction. This structure allows the gap between the rollers to be controlled using springs on the sides, making it possible to strongly hold the raw material fed between the rollers. The outer diameter of the roller is selected depending on the length of the rotating drum 1, that is, the width of the machine, the purpose of processing, and the material or length of the raw material to be processed, but the minimum diameter of the roller that is usually put into practical use is about 1 inch. If it is below, it cannot withstand use in terms of mechanical strength. Generally, when operating this device, there are many continuous operations by automatic feeding of raw materials, and therefore an adjustment device or a cutting roller 44a at the tip of the feeding device is used to flatten the raw materials lined up on the feeding device 3. , 4b is usually installed to improve the efficiency of biting. Furthermore, the feeder 3 for raw materials is fed horizontally to the center of the rotating drum, and the tip of the feeder 3 and the biting roller 4
There is some play between a and 4b to adjust the gap between the biting roller and the needle-like protrusion 2, but when processing the natural fibers mentioned above, the length of the fibers must be at least 1 inch or more, and the Since the aggregates are large, the raw materials bitten by the biting rollers 4a and 4b are discharged by rolling up the aggregates that are sent in one after another, and there is no problem in continuous operation. This structure is considered to be sufficient if the fiber has a length of about 2/3 or more of the outer diameter of the biting roller.

In addition, as previously disclosed in Japanese Patent Application Laid-open No. 181760/1983, the present applicant sent short carbon fiber aggregates of about 3 to 10 mm between a pair of rotating bodies each having a large number of needle-like protrusions on the surface. Invented a method and device for dispersing the aggregates into single fibers in a dry state by varying the surface speed, suppressing aggregates with the needle-like protrusions of the slower rotating body, and scraping them off with the needle-like protrusions of the faster rotating body. did. In order to prevent the dispersed short carbon fibers from coming into contact with each other and agglomerating, before mixing the short carbon fibers into the raw material powder for the molded product, dry silica fume or the like with a diameter of about 0.1μ to 1μ. We proposed that submicron fine powder or fine fibers be adsorbed and interposed on the surface of each monofilament, and the following three methods of manufacturing the same were proposed.

(1) A method in which short carbon fibers are dispersed and sequentially introduced into a mixer in which the fine powder or fine fibers are dispersed in a mist.

(2) A method of adsorbing and intervening by sequentially spraying the fine powder or fine fibers mentioned above while dispersing small pieces of short carbon fibers.

(3) A method of dispersing the fiber material and at the same time imparting the above-mentioned treatment effect in a state in which small pieces of short carbon fibers and the above-mentioned fine powder or fine fibers are mixed in advance.

(Problem to be Solved by the Invention) In recent years, various fibers such as nylon, vinylon, polypropylene, glass, carbon, aramid, and silicon carbide have been artificially produced in factories, and these fibers can be made into metal, glass, and plastic depending on the purpose. ,
Reinforced composite materials to increase mechanical strength by combining various materials such as ceramics, refractories, concrete, and mortar with fibers, or electromagnetic shielding that takes advantage of the characteristics of each material, surface heating concrete and mortar, etc. It is rapidly becoming popular or under development in various fields as an alternative fiber to asbestos, which is a hot topic of public pollution problems. These fiber diameters are approximately 7μ to 18μ
There are many types of fibers, depending on the purpose, such as continuous long fibers, chopped short fibers made by bundling a large number of such single fibers with a binder and cutting them, cross shape, filter shape, short fiber shape, whisker shape, etc. Selected and used. On the other hand, in order to use carbon, aramid, etc. in the fibers for reinforcing materials such as refractories, PC concrete, mortar, etc., they must be monofilament-like due to their chemical stability, and unless there is a special purpose, the aspect Generally speaking, short fibers having a length of about 3 mm to 10 mm are required to be randomly mixed in from the ratio.

However, even if an attempt was made to disperse the above-mentioned short fiber aggregates of about 3 to 10 mm using the conventional technique shown in Figure 2, the short fibers bitten by the pair of biting rollers were short in length, so It is impossible to roll up the short fibers that are fed into the machine, and it is impossible to continuously supply the fibers, making it impossible to achieve the desired purpose.

In addition, in the conventional technology disclosed in Japanese Patent Application Laid-Open No. 58-181760, when trying to speed up the rotation of the main drive part or to increase the charge amount per unit of supplied raw material beyond a certain limit in order to increase the capacity of the device, the dispersion effect occurs. On the other hand, if the operating time of one batch is too long, the fibers tend to become granulated in the mixer, which naturally leads to certain limitations on the correlation between fiber processing capacity and mixer capacity. There is a problem in the processing capacity compared to the cost of the resulting equipment, and when attempting to simplify the process by processing agglomerated small pieces of short carbon fibers in a mixed state with the above-mentioned fine powder or fine fibers, the low-speed rotation of the dispersion equipment is difficult. The surface of the drive unit is clogged with the fine powder, etc., which hinders long-term continuous operation, and for the reasons mentioned above, it is difficult to speed up the rotation of the drive unit. It had problems such as not being able to bring out the effects.

(Means for Solving the Problems) The present invention aims to solve the above problems, and aims to pass short fiber aggregates of about 3 to 10 mm between a pair of belt conveyors to form a large number of small protrusions on the outer peripheral surface. The short fibers are forcibly fed toward the approximate center of the protruding rotating body, and fed between the small protrusions of the rotating rotating body while being clamped and held by a pair of guide rollers at the tip of a belt conveyor. A method of dispersing aggregates into single fibers. A pair of belt conveyors are disposed toward the center of a rotary body with many small protrusions protruding from the outer peripheral surface, and a pair of guide rollers are disposed at the tip of the outlet of the belt conveyor, and at least one of the belt conveyors is provided with a gap. It is characterized by a device that is movable in the direction of contraction and that disperses short fiber aggregates in the form of single fibers so that short fiber aggregates of about 3 to 10 mm can be clamped and held and sent between the small protrusions of a rotating body. It is.

(Function) In the present invention, short fiber aggregates of about 3 to 10 mm are rolled up together while passing between a pair of transfer devices such as belt conveyors, and are continuously fed toward the center of a rotating body. While the aggregates are held in place at the tip of the rotating body, they are caught by the many small protrusions on the surface of the rotating body and dispersed into single fibers, causing clogging even if fine powder is mixed in the aggregates. It can be operated continuously for a long time without any trouble.

(Example) Hereinafter, a detailed explanation will be given based on the example shown in FIG. 10 is a cylindrical rotating drum with a large number of needle-like protrusions 11 protruding from its surface, 400 mm in diameter, 980 r.
It is rotating in the direction of the arrow at pm. 12 is a mixture of short fibers such as pitch carbon short fibers and aramid short fibers of about 3 to 10 mm, and inorganic fine powder such as silica fume with a particle size of 0.1 μ to 1 μ. 0 A raw material consisting of aggregates mixed with inorganic fine fibers such as asbestos tailings of 1 μ to 1 μ. 13 is a horizontally arranged belt conveyor for supplying the raw material, which moves in the direction of the arrow and moves toward the tip from guide rollers 14 and 15. is directed toward the center of the rotating drum 10, and a small gap is provided between the tip of the vertical portion 13' and the needle-like protrusion 11.
Reference numeral 16 denotes a belt conveyor for biting disposed approximately parallel to the vertical portion 13', and is movable in the direction of the arrow, and its tip guide roller 17 is constantly conveyed to the vertical portion 1 of the belt conveyor 13 by means of a spring disposed on the side.
3' is pressed toward the guide roller 18 at the tip. Reference numeral 19 denotes an auxiliary belt conveyor disposed horizontally above the guide roller 15 and is movable in the direction of the arrow. Reference numeral 20 is a casing, which is wound along the rotating direction of the rotating drum 10 from the tip of the vertical part 13' of the belt conveyor 13, and the distance between it and the rotating drum 10 gradually increases, and the casing slides vertically up and down. The spacing can be adjusted.

Next, the effect will be explained. The raw material 12 supplied to the belt conveyor 13 is held down by the auxiliary belt conveyor 19, and is connected to the vertical part 13' of the belt conveyor 13 and the biting belt conveyor 1.
It is sent from above between 6 and forcibly transferred between the two. During this time, the raw material 12 consisting of short fiber aggregates of about 3 to 10 mm is rolled up together and forcibly transferred to the tip, held by the guide rollers 17 and 18 at the tip, and sent out while being held in the needle shape of the rotating drum 10. It is scraped off by the projections 11 and dispersed into single fibers. The dispersed single fibers are combined with the fine powder and gradually expand in volume through the gaps that are gradually widened by the strong air flow generated by the rotation of the rotating drum 10, thereby further promoting the formation of single fibers. Also, mixing with fine powder is promoted at the same time and sent to the next process. In the next process, raw material powder such as cement is injected in a fixed amount to produce a dry compound in which short carbon fibers are uniformly mixed in at a high rate.

[Example of mixing with molded product raw materials]

1 (1) Pitch-based short carbon fiber (length 3mm)
5% (weight ratio) (2) Inorganic fine powder (silica hume, particle size 0.1μ ~
1μ) 10% (〃) (3) Cement 50% (〃) (4) Aggregate (silica sand No. 6) 35% (〃) 2 (1) Aramid short fiber (length 6 mm) 10% (weight ratio) ( 2) Inorganic fine fibers (asbestos tailings, diameter 0.01μ)
〜1μ) 15% (〃) (3) Cement 75% (〃) (Effect) The present invention uses short fiber aggregates of about 3 to 10 mm to
It is forcibly fed through a pair of belt conveyors toward the approximate center of the rotating body, which has many small protrusions protruding from the outer circumferential surface of the body, and is held and held by a guide roller at the tip of a pair of belt conveyors while rotating. A method of dispersing short fiber aggregates into single fibers by sending the short fibers between the small protrusions of a rotating body.

A pair of belt conveyors are disposed toward the center of a rotary body with many small protrusions protruding from the outer peripheral surface, and a pair of guide rollers are disposed at the tip of the outlet of the belt conveyor, and at least one of the belt conveyors is provided with a gap. The gist is a device that is movable in the shrinking direction, holds short fiber aggregates of about 3 to 10 mm in size, and disperses the short fiber aggregates into single fibers so that they can be sent between the small protrusions of the rotating body. has the following advantages compared to prior art dispersion methods and devices:

(1) It has a wide range of processing capacity because there is no problem with the length of processed fibers.

(2) The peripheral speed of rotation of the main driving part of the device is high, and the dispersion and mixing of the short carbon fiber aggregates and the fine powder or fine fibers can be simultaneously processed;
Work efficiency is good because the spraying effect can be brought out, and the agglomeration prevention treatment effect is also reliable.

(3) Since the equipment structure is simple, maintenance is easy for continuous operation, and equipment costs are reduced relative to efficiency.

In addition, it is possible to use a dry carbon short fiber raw material that has been subjected to agglomeration prevention treatment obtained by the device according to the present invention, or to link the device with a powder mixing mixer or a powder metering injection device, etc. Therefore, short carbon fibers, etc. can be uniformly distributed in the dry state in powders such as cement and refractories, which were previously thought to have an upper limit for industrial production, or in raw materials for molded products that have differences in specific gravity and particle size. It is possible to easily produce a dry compound with a high mixing rate.

[Brief explanation of drawings]

FIG. 1 is a front view of one embodiment of the apparatus of the present invention, and FIG. 2 is a front view of a first comparative example of the prior art. 10...Rotating drum, 11...Acicular projection, 12
...Raw materials, 13...Belt conveyor, 14,
15, 17, 18... Guide roller, 16...
Belt conveyor for biting, 20...Casing.

Claims (1)

[Scope of Claims] 1. A short fiber aggregate of about 3 to 10 mm is forcibly fed through a pair of belt conveyors toward the approximate center of a rotating body having a large number of small protrusions protruding from its outer peripheral surface. A method in which short fiber aggregates are dispersed into single fibers by the small protrusions of a rotating body that is held between guide rollers at the tips of a pair of belt conveyors and fed between the small protrusions of a rotating body. 2. A pair of belt conveyors are arranged toward the center of a rotating body with many small protrusions protruding from the outer peripheral surface, and a pair of guide rollers are arranged at the tip of the outlet of the belt conveyor, and at least one of the belt conveyors is provided with a gap. This device is movable in the direction of contracting the short fiber aggregates, and is capable of dispersing the short fiber aggregates into single fibers in such a way that the short fiber aggregates of about 3 to 10 mm can be held between the small protrusions of the rotating body.