JPS625810A - Disperser for short fiber lump - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for dispersing short fiber agglomerates of m-fibers for reinforcing inorganic materials such as carbon fibers, glass mm, ceramic fibers, etc. By using the dispersed short fibers, Enables uniform dispersion of fibers in inorganic materials, M&
The ratio of strength increase to fiber addition width can be increased.

Dog, no! Reinforced materials are well known, such as concrete and gypsum board, to which lightweight yet strong carbon fibers, alkali-resistant glass fibers, and the like are added.

The reinforcing m-fibers for such reinforcing materials are short fibers with a length of about 5 to 10 mm, which are relatively easily produced and available at low cost.1 A typical example is pitch-based carbon m-fibers. However, it is usually in the form of small clumps of tangled fibers, like cotton.

Even if this form is used in a conventional concrete or mortar mixer to try or add it to wet cement or gypsum, the reinforcing fibers will remain entangled, and no matter how powerful the mixing is, it will not be completely shortened. It is fibrous and difficult to disperse uniformly. Therefore, the manufactured reinforcing material cannot achieve the originally expected sufficient strength depending on the amount of short fibers added.

One way to solve this problem is to use a pair of movable bodies equipped with a large number of needle-like protrusions, and to comb small pieces of short carbon am between the needle-like protrusions that intersect and move relative to each other. A method has been proposed in which the fibers are made into short fibers and then mixed into raw materials for concrete, mortar, etc.
60).

However, it is difficult to expect complete dispersion into short fibers using such mechanical methods.

Problems to be Solved by the Invention The present invention solves the problems of the present invention as described above.
It is an object of the present invention to provide an apparatus for efficiently dispersing lumps into individual short fibers, and also to provide an apparatus for uniformly mixing the dispersed short fibers and an inorganic material.

Configuration of the Invention Means for Solving the Problems The mixing device for dispersing short Pa fibers into an inorganic material according to the present invention comprises a dispersion chamber consisting of a cylindrical body with a closed top and an open bottom; Gas and short inserted vertically along the axis of the cylinder from! a) Consists of a male mass supply pipe and a circular collision plate installed at the center of the bottom of the cylindrical body.

In order to mix the short fibers dispersed by this device into the inorganic material, a lower part of the above-mentioned short fiber mass dispersing device is placed.
A hollow cylinder having the same inner diameter as the above-mentioned cylindrical body, having a height greater than the height of the dispersion chamber, and having a gas vent made of a mesh filter on the lower side surface thereof, and a stirrer having the same inner diameter as the hollow cylinder. A mixing device for inorganic material and dispersed short HIA fibers is installed, which has a structure in which mixers are directly connected in sequence.

This will be explained in detail with reference to the accompanying drawings. FIG. 1 is a side sectional view showing a case where a mixing device for dispersed short fibers is installed below the short fiber mass dispersing device of the present invention.

A gas and short fiber mass supply pipe 13 is inserted vertically from the top of the dispersion chamber 12, which is made up of a cylinder 11 with a closed top and an open bottom, along the axis of the cylinder. A circular collision plate 14 is installed in the center to constitute the short fiber mass dispersing device 1.

At the bottom of this dispersion device l, there was a dispersion chamber with the same inner diameter as the cylindrical body 12 and a height >L) greater than or equal to the height of the dispersion chamber, and a gas vent consisting of a mesh filter 21 was provided on the side surface of the lower part. A short tawr mixing device in which an inorganic material is dispersed has a structure in which a hollow cylinder 2 and a mixer 3 having the same inner diameter as the hollow cylinder 2 and containing a stirrer 31 are directly connected in sequence.

The shape of the upper closed portion 15 of the cylindrical body 11 in the dispersion chamber 12 is not limited to the truncated cone shape illustrated in FIG. I can do it.

In order to install the circular collision plate 14 at the center of the lower end of the cylinder, as illustrated in FIG. There is a method of extending and supporting it, but in either case, the area around the circular collision plate 14 is open so that gas and dispersed short jabs can freely pass through.

Further, the wire mesh 16 may be a metal wire mesh, but a soft net made of fiber material is preferable in order to prevent damage to the cut hat of the dispersed m-fibers.

Note that a mesh filter 21 constitutes a hollow cylindrical gas vent.
Since short fibers tend to accumulate on the mesh filter, as shown in the partial cross-sectional perspective view in Fig. 2, by attaching a brush 4 to brush the mesh filter from the inside, it is possible to effectively prevent short fibers from accumulating on the mesh filter. can be prevented.

It is convenient to attach the brush 4 so that it is directly connected to the rotating shaft 32 of the stirring fi 31 provided in the mixer 3 and rotates, since there is no need to provide a special brush drive mechanism.

The high-speed gas flow fed into the dispersion chamber 12 from the supply pipe 13 of working gas and short ta fibrils hits the circular collision plate 14 located directly below the tip of the supply pipe 13, reverses once, ascends the dispersion chamber side wall, and is dispersed. It turns around in the northern part of the room and heads downward. A portion of the gas flow further repeats this reversal motion, resulting in a highly agitated gas flow state inside the dispersion chamber.

The cotton-like short fiber mass entangled with am, which is sent from the supply pipe 13 to the dispersion chamber 11 along with the high-speed gas flow, is dispersed by the impact on the collision plate 14 and the gas flow in a highly agitated state. The fibers are loosened and dispersed into individual fibers, which pass through the gaps of the net 16 and fall.

Therefore, in order to collect the dispersed fibers, a collection bar, filter, etc. may be attached to the outlet side (net 16 side) of the dispersion device.

The short fibers dispersed in this way are taken out and mixed with a separately prepared inorganic material. Although it may be supplied to a mixing device with I, it is convenient to have a structure in which the mixing device is directly connected to the lower part of the dispersing device as shown in FIG.

Since the diameter of the hollow cylinder 2 in the mixing device is larger than the diameter of the gas and short fiber mass supply pipe 13, the airflow velocity here decreases, and the dispersed short fibers are in a state of gentle flow. . Further, the gas flow flows out from the mesh filter 21, so that directly above the mixer 3, the short Iam is in a free-falling state and is successively dispersed onto the surface of the inorganic material being stirred in the mixer.

The height of the hollow cylinder 2 is set to be greater than or equal to the height of the dispersion chamber (L) in order to avoid turbulence in the stirring air flow occurring in the dispersion chamber, and also to prevent the dispersed short fibers from flowing into the mixer. This is to allow room for uniform diffusion in the space above the inorganic material being stirred inside.

Inorganic raw material 1 obtained by mixing the short fibers, such as carbon fiber, which are successively dispersed in this way, such as cement raw material that hardens by hydration, is poured from a mixer into a mold installed outside and solidified. Carbon fiber reinforced concrete with extremely good carbon/N/fiber dispersion is produced.

Note that the gas used in the apparatus of the present invention is usually air, but nitrogen or other gas may be used as necessary.

Mouth” (1 Specific gravity as carbon fiber: 1.63. Diameter 14.5 tiles.

Length 10 mm, tensile strength 7800 Kg/
cm 2 multilayer pitch-based carbon fiber (manufactured by Kureha Chemical Co., Ltd.) was used.

About 500 g of a mixture of early strength cement, water, and powdered silica sand in a ratio of water: early strength cement = 50 + 100 (weight ratio) powdered silica sand: early strength cement) = 25: 100 (same) was added as shown in Figure 1. The above-mentioned carbon fibers dispersed using the apparatus shown in 3. and 5%, respectively, and were sequentially sprinkled and mixed over about 10 minutes.

For comparison, reprinted undispersed carbon fibers were added to cement mixtures of the same composition at volumetric mixing ratios of 1, 3. A sample was prepared by adding 5% and antifoaming agent and mixing with an Omnimixer (manufactured by Chiyoda Giken Kogyo Co., Ltd.).

After molding each sample into a 40x40x160mm mold, 2
The mold was removed after 4 hours, and standard curing was performed at 20±3°C, and the compressive strength was measured at the age of 70.

The measurement method was carried out according to 1IsR5201.

The results are shown in Figure 3 (average value of 3 samples).

The horizontal axis is the carbon fiber volume mixing ratio (%), and the vertical axis is the compressive strength (K
g/cm2), 0 mark indicates a sample manufactured according to the present invention, and Φ mark indicates a comparative sample.

1. As shown in Figure 3, the compressive strength tends to decrease as the amount of carbon fiber added increases with the conventional device, whereas the compressive strength of the device with the present invention decreases as the amount of carbon fiber added increases. Even when the compressive strength was increased, the compressive strength did not decrease, but rather increased.

[Brief explanation of the drawing]

FIG. 1 shows a structure in which a brush 4 is attached to brush the mesh filter from the inside in a cross-sectional perspective view when a mixer a of dispersed short fibers is installed at the bottom of the short fiber mass dispersion device according to the present invention. Figure 3 shows the results of measuring the compressive strength of samples manufactured by the apparatus of the present invention and comparative samples, and the horizontal axis shows the carbon fiber volume mixing ratio (%).
), the vertical axis is the compressive strength (Kg/cm2), the O mark indicates a sample manufactured by the apparatus of the present invention, and the * mark indicates a comparative sample.

Claims (1)

[Claims] 1. A dispersion chamber consisting of a cylindrical body with a closed top and an open bottom, a gas and short fiber mass supply pipe inserted vertically from the top of the dispersion chamber along the axis of the cylinder, and A short fiber mass dispersion device consisting of a circular collision plate installed at the center of the bottom of a cylindrical body. 2. A hollow cylinder having the same inner diameter as the above-mentioned cylindrical body and a height greater than or equal to the height of the dispersion chamber, and having a gas vent made of a mesh filter on the side surface of the lower part, and having the same inner diameter as the hollow cylinder. 2. The apparatus for dispersing short fiber lumps according to claim 1, comprising a mixing apparatus for mixing an inorganic material and dispersed short fibers, which has a structure in which mixers each having a built-in stirrer are directly connected in sequence. 3. The apparatus for dispersing short fiber lumps according to claim 2, which comprises a brush attached to the lower side surface of a hollow cylinder installed at the lower part of the dispersion apparatus so as to brush the net filter from the inside.