JPS6022088B2 - Dry fine powder raw material production equipment containing short carbon fibers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an apparatus for producing a dry fine powder raw material containing short carbon fibers in which short carbon fibers are uniformly split and mixed into single fibers.

(Subsidiary technology) Carbon fibers made from raw materials such as pitch and having a length of about 5 to 20 mm, and short fibers obtained by cutting these fibers into various lengths of about 10 mm are well known.

In addition, molded products or parts such as various mortars, concrete, glass, metals, resins, etc., made by uniformly dispersing and mixing the above-mentioned short carbon fibers, have significantly increased mechanical strength without impairing heat resistance or chemical stability. It is also known to increase. However, there are great difficulties in uniformly dispersing short carbon fibers in powder or fluid raw materials before shaping to produce this type of product.

In other words, when a large number of short carbon fibers are aggregated, when some force is applied such as vibration, vibration, or other force, the adjacent short fibers can move together, just like when short fine hairs are swept together. They intersect and overlap each other to form soft, cotton-like aggregates.

Although the adhesive bond between each short twill in this aggregate is not very strong, it cannot be easily loosened with fingers. However, the above-mentioned properties of short carbon fibers are a major drawback when they are added to a powdered or fluid raw material before being formed into a molded article and uniformly dispersed and mixed. This is because when short carbon fibers are mixed into the raw material for a molded product in the form of an aggregate containing many small aggregates as described above, these aggregates are likely to cause damage to the raw material in subsequent processes such as mixing, drilling, etc. Even with ordinary dispersion methods, the single fibers cannot be separated, and even the once separated short carbon fibers re-agglomerate into a spherical shape in the raw material for the molded product. This is because it is not possible to obtain separated single fibers in a uniformly dispersed state.

Therefore, extremely complicated methods must be used to obtain raw materials for mortar, slate plates, cast concrete molded products, etc. in which the short carbon fibers described above are uniformly mixed.

That is, an aggregate of short carbon fibers is put into a suitable liquid material such as water to be mixed with cement, or into a fluidized raw material containing cement, and is mixed little by little with a special mixer, etc., to uniformly disperse it in a fluid state. It is necessary to undergo an operation to form a solid-liquid mixture. It goes without saying that the above method, which can be called a wet method, is inefficient and roundabout.

Recently, this type of molding material has come to be distributed as a single package containing a mixture of various solid material additives, and if necessary, it can be kneaded with water or the like to form mortar.

This is a so-called premixed composite product. However,
Due to the above-mentioned problems, it is not possible to create a one-package product of solid powder/granular composite material with added short carbon fibers, and even if it were made, the short carbon fibers would aggregate over time, making it unusable. .

This is extremely inconvenient and does not match the trends of the times. As described above, although there are great expectations and demands for mortar containing short carbon fibers, slate boards, cement tiles, and concrete molded products due to their excellent properties, there is very little actual implementation of these products. The current situation is that it is a thing.

Therefore, it would be advantageous if a composite cement could be obtained in which all the short carbon fibers are relatively sufficiently separated and dispersed from the beginning in a dry state in a granular solid raw material containing the above-mentioned cement powder.

Similarly, it would be of great benefit if short carbon fibers could be dissolved into single fibers and mixed into various molten glasses, molten resins, and uncured resin raw materials in a dry state as described above. . In order to do this, it is necessary to mechanically separate the aggregated aggregated short carbon fibers into single fibers by a so-called dry method without using liquid soot, or to prevent the agglomeration tendency and separate the single fibers into a vertical state. It is necessary to add it to the raw material as is.

However, there have been no examples of large companies attempting to defibrate short carbon fibers using the dry process and finally succeeding. (Objective) The object of the present invention is to provide a manufacturing apparatus for obtaining a dry fine powder raw material in which short carbon fibers are dispersed and mixed in the form of single fibers.

(Structure) In order to achieve the above-mentioned object, the present invention includes a pair of rotating bodies each having a large number of thin protrusions erected at small intervals on its surface, which are disposed opposite to each other so that the tips of both protrusions are relatively interlocked with a small gap. A short carbon fiber aggregate supply device is installed above the bag, and a sweeper roll is installed below the pair of rotating bodies to prevent the short fibers from moving by adhering to the circumferential surface of each rotating body and attempting to rotate. The opposing parts of the pair of sweeper rolls are placed opposite each other so as to move relative to each other with a large gap, and the separated short carbon fibers are mixed with the fine powder raw material by passing between the pair of rotating bodies and the pair of sweeper rolls. It is characterized by having means.

Hereinafter, a detailed explanation will be given based on an example. 1 is a thick-walled steel cylindrical rotating body with an outer diameter of 40mm and a width of 8mm;
is a similar rotating body with an outer diameter of 20 mm and a width of 80 mm.

Each of the rotating bodies has grooves extending in the circumferential direction at intervals of about three ribs in a helical pattern on the surface. In this groove, an iron cotton-like body having thin protrusions arranged in a serrated manner is embedded and fixed with the thin protrusions facing upward. These thin processes have a pointed triangular tip, a pitch of 3 sails, and a height of 6 skins. The cylindrical rotating body 1 and the rotating body 2 are fixed at a predetermined interval so that the tips of the thin protrusions 3 and 4 on both circumferential surfaces face each other several distances apart without contacting each other. The rotating bodies 1 and 2 are supported by a motor and a transmission (not shown) so that they can rotate counterclockwise in the drawing. In this example, sweeper rolls 5 and 6 are in contact with a portion of the circumferential surface of the rotating body 1, and sweeper rolls 7 and 8 are also in contact with the circumferential surface of the rotating body 2. A hopper 9 for carbon short fiber aggregates 11 is fixedly arranged above the center of the rotating bodies 1 and 2. Reference numeral 10 denotes a flywheel device into which various raw materials such as cement mortar, concrete materials, or admixtures are input.

Next, the effect will be explained. The average length of the hopper 9 is approximately 15 mm, and the average length is approximately 3 mm. Gosara short carbon fiber aggregate 1
1 is contained, and most of this aggregates into cotton-like small lumps of irregular size. This short carbon fiber aggregate 11 is supplied from the lower supply port to the upper portions of the opposing peripheral surfaces of the rotating bodies 1 and 2 by vibrating the hopper 9. At this time, the rotating body 1 is rotating counterclockwise at a speed of 400 revolutions per minute, and the rotating body 2 is rotating counterclockwise at a speed of 20 revolutions per minute. Therefore, the supplied short carbon fiber aggregates 11 are stopped by the thin protrusions erected on the surfaces of the two rotating bodies at various locations, and are pulled in opposite directions, and almost all of the short carbon fiber aggregates 11 are It moves downward according to the rotation of . During this time, most of the single fibers of the carbon short fiber aggregate 11 are separated one by one, and further fall downward through the gap between the peripheral surfaces of the sweeper rolls 5 and 7. in this case,
The single fibers attached to the circumferential surfaces of the rotating bodies 1 and 2 and attempting to rotate are prevented from moving by the sweeper rolls 5 and 7. In this way, the short carbon fibers are surprisingly completely separated into individual fibers while falling downward from the gap between the sweeper rolls 5 and 7.

When the fallen fibers were observed under a microscope, there was almost no damage to the surface of each single binding, and only a few were cut. Then, the short carbon fibers that have been completely loosened into single fibers fall into the rope sanding device 10, and the rope sanding device 10
The powder is uniformly mixed into various powdered raw materials such as cement mortar, concrete materials, or admixtures.

The short carbon fibers that are individually woven in the various powder raw materials do not re-agglomerate. (Effects) According to the present invention, a pair of rotating bodies each having a large number of fine protrusions erected at small intervals on the surface are placed facing each other so that the tips of both protrusions move relative to each other with a gap of a certain value, and the short carbon fibers are aggregated upward. A collection supply device is disposed, and a sweeper roll is provided below the pair of rotating bodies to prevent movement of short fibers that adhere to the circumferential surface of the rotating bodies and try to rotate, and the pair of sweeper rolls face each other. A pair of rotating bodies and a
Since it is equipped with a means for mixing the short carbon fibers that have been loosened by passing between a pair of sweeper rolls with various powder raw materials, it is possible to obtain a dry fine powder raw material in which the short carbon fibers are dispersed and mixed in the form of single fibers. can.

[Brief explanation of the drawing]

The figure is a front view of one embodiment of the present invention. 1, 2...Rotating body, 3, 4...Thin protrusions, 5
, 7...Sweeper roll, 9...Hopper, 10...Dense clothing layer, 11...Carbon short fiber aggregate.

Claims (1)

[Claims] 1. A pair of rotating bodies each having a large number of thin protrusions erected at small intervals on the surface thereof are placed facing each other so that the tips of both protrusions move relative to each other with a small gap, and a carbon short fiber aggregate supply device is arranged above. ,
Sweeper rolls are provided below the pair of rotating bodies to prevent the movement of short fibers that adhere to the circumferential surfaces of the rotating bodies and attempt to rotate, and the opposing parts of the pair of sweeper rolls are moved relative to each other with a small gap. A dry-type fine powder raw material production device containing carbon short fibers is provided with means for mixing carbon short fibers separated by passing between a pair of rotating bodies and a pair of sweeper rolls with a fine powder raw material.