JPS593133B2 - Fiber-reinforced cement manufacturing method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for producing fiber reinforced cement by combining a jet of cement paste with a fiber bundle.

Conventionally, methods for manufacturing composite materials such as fibers and cement include methods of thoroughly mixing glass fibers and cement, and molding and hardening the mixture by casting and pressing;
Alternatively, a method is known in which chopped strands of glass roving are cut to a required length are formed into a mat shape, and this is laminated with cement paste and molded and hardened.

However, in the former method, the glass fibers may be damaged when mixing the glass fibers and cement.
The particles intertwined in lumps, making it difficult to mix them uniformly and making it difficult to obtain a product with stable quality.

In addition, glass fibers are usually made of several hundred fibers that are tightly bound together using a sizing agent or a surface treatment agent, in order to improve the operability when spinning the glass fibers and to improve the adhesion with the matrix when making composites. In the latter method, the glass roving is cut to the required length (2
It is difficult for the cement paste to enter between the fibers of the chopped strand cut into ~5 crn ), and as shown in FIG. were integrated in such a situation that they were surrounded by cement paste 2, forming a fiber-cement composite, and it was not possible to obtain a sufficient reinforcing effect by the glass fibers.

The present invention provides a fiber-reinforced cement that could not be obtained by such conventional methods, that is, a high-strength fiber-reinforced cement in which cement paste is relatively uniformly interposed between the fibers of the fiber bundle and has a high fiber filling rate. It is an object of the present invention to provide a method for obtaining a composite material and an apparatus for producing a fiber-reinforced cement composite material that is effective in carrying out the method.

More specifically, the method of the present invention injects a flow of cement paste onto a fiber bundle in a stretched state, spreads the fiber bundle with the flow of cement paste, and at the same time spreads cement paste between the spread fibers. This is characterized by forming fiber-reinforced cement in which cement is interposed between the fibers.

The fiber bundle used in the present invention includes not only inorganic fibers such as glass fiber and carbon fiber, but also organic fibers such as nylon and polyester, hemp and other natural fibers, etc. In addition to Portland cement, it also includes plasters such as gypsum and lime.

When entering cement between the fibers of such a fiber bundle, both ends of the fiber bundle are held and supported in a stretched state.
A flow of cement paste is injected from a nozzle arranged opposite to this, and the flow of cement paste spreads the fiber bundles. At the same time, the cement paste enters between the spread fibers, and as shown in Fig. 2, each fiber bundle is opened. Fibers 1a, 1a,...
- Obtain fiber-reinforced cement in which cement paste 2 is dispersed relatively uniformly.

Note that Figure 2 schematically shows the state in which each fiber is completely opened, and depending on the type of fiber and the strength of the jet of cement paste, multiple fibers may be mixed together without being opened. However, there is no problem as long as they are dispersed relatively uniformly.

In such a case, it is sufficient to hold both ends of the fiber bundle to the extent that it prevents the fibers from becoming entangled with each other due to being suppressed by the flow of cement paste, and maintains their alignment to that extent. The strength of the jet must be such that the jet acts on each fiber and displaces it, but does not damage the fiber bundle.

The cement paste injected onto the fiber bundles is made by adding approximately 25 to 100 parts by weight of water to 100 parts by weight of cement, giving appropriate fluidity depending on various conditions, but do not use more water than necessary. It is more advantageous not to add it, and the fluidity can be adjusted by appropriately using a dispersant, a water reducing agent, etc.

When injecting a flow of cement paste onto a fiber bundle, as illustrated in FIG. The cement paste stream 1 is fed from a nozzle 14 arranged opposite to the fiber bundle 13 between the guide rollers while being wound around the guide rollers 12, 12 and continuously fed.
Although it is desirable to eject the fiber bundle 1a and wind up the fiber bundle in the winding tool 15, the fiber bundle 13 is wound around the winding tool 15 in advance, and the fiber bundle is rolled up in the cement paste 11 in the processing tank 10. Fiber-reinforced cement composites can also be formed by injecting a stream of cement paste over the fiber bundles at the surface of a winder, or without the use of such a treatment bath.

The fiber bundle that has been associated with the cement paste in the manner shown in FIG. A fiber bundle coated with cement paste is wrapped around a plate shape as shown in the figure and cured to form a molded product with fiber-reinforced cement coated around it using the winding tool 15 as a core material, or the rolled The handle can be made into a cylindrical molded article, and the winder can be removed after the fiber-reinforced cement has hardened, or the fiber bundle can be wound into a suitable winder. It is also possible to immediately remove it from the winder or cut it and mold it into a desired shape.

Next, an embodiment of the fiber-reinforced cement manufacturing apparatus of the present invention will be described with reference to FIG.

In this device, 20.20 indicates a glass roving pan, and glass rovings 21, 2 derived from this
Guide rollers 23, 23, and 24 are arranged to guide the wafer 1 to the processing tank 22.

The processing tank 22 is filled with a required amount of cement paste 25, and the bottom part 22a of the tank is formed into a funnel shape to prevent the formation of a precipitated layer of fine cement particles, and a slurry pump 26 is installed at the bottom end to circulate the cement paste 25. established,
The discharge port 27a of the circulation pipe 27 is located below the liquid level of the cement paste 25 in the processing tank 22.

The circulation of the cement paste by the slurry pump 26 is not only for preventing precipitation of fine cement particles, but also for keeping the concentration of the cement paste uniform at all times through the flow of the cement paste and for suppressing its hardening.

Further, the cement paste supply pipe 28 is used to replenish the cement paste 25 sent out from the processing tank 22 together with the glass roving 21, and is connected to a mixing tank (not shown) that supplies cement paste mixed in advance at a required mixing ratio. The discharge port 28a of the supply pipe 28 is connected to the processing tank 22.
It is located below the liquid level of the cement paste 25 in.

The reason why the discharge ports of the circulation pipe 27 and the supply pipe 28 are located below the liquid level of the cement paste 25 is to prevent the cement paste flowing out from these discharge ports from scattering, and also to prevent the cement paste from scattering into the cement paste 25. This is effective in preventing air bubbles from entering the molded product and preventing air bubble-based defects from occurring in the molded product.

Inside the treatment tank 22, guide rollers 29 and 30 are provided to guide the glass roving 21 introduced therein, and these guide the glass roving 21 wound around the idle rollers 29 and 30 onto the surface of the cement paste 25. The cement paste 2 is wound up on a winding device 33 through two pairs of rollers 31, 31 and 32.32 arranged between the guide roller 30 and the pair of rollers 31.31.
A nozzle 34 is provided below the liquid level of the glass roving 21 to face the glass roving 21 and inject a flow of cement paste thereto.

This nozzle 34 pressurizes the cement paste 25 sucked in from a suction pipe 35 opening at the bottom of the processing tank 22 in a pressure generator 37 such as a reciprocating pump driven by a drive device 36 such as a hydraulic unit, and then sends it out. Since the jet is ejected through the pipe 38, and its jet port is opened below the liquid level of the cement paste, the cement paste does not scatter as in the case of the circulation pipe 27 and the supply pipe 2B, and the cement paste does not flow into the cement paste. It does not introduce air bubbles.

In the cement paste 25, a plate-shaped separator 39 arranged behind the glass roving that receives the cement paste flow from the nozzle 34 prevents the glass roving from being disturbed and enhances the effect of the cement paste flow from the nozzle 34. It is for.

The glass roving 21, which has received the cement paste flow from the nozzle 34, is untied by the action of the cement paste flow and is opened, that is, separated into individual fibers. The cement paste flows into the rollers 31, 31, and is refocused by the pair of rollers 31, 31, and the adhesion amount of the cement paste is adjusted by applying appropriate pressure.
sent to.

The winding device 33 is configured to rotate a winding drum 40 as shown in the figure or a plate-like or other winding member at a constant speed by a motor 41, and winds the glass roving in multiple layers as necessary. Therefore, the entire winding can be reciprocated in the direction of the axis of rotation for winding (in the direction perpendicular to the paper plane in FIG. 4).

In addition, when using this device to simultaneously apply cement paste to multiple glass rovings,
Those glass rovings are moved to guide rollers 23, 23.
Nozzles 34, 34 . ...
The glass rovings may be configured to inject a cement paste stream through the glass rovings.

As detailed above, according to the method and apparatus of the present invention, it is possible to fill the cement paste between the fiber bundles relatively uniformly by simple means, and in a highly oriented and dense manner, as described below. A fiber-reinforced cement product of extremely high quality can be obtained.

However, in the present invention, since the cement paste is strongly press-fitted into the fiber bundle, it is possible to use a very large number of fiber bundles tied together, which greatly facilitates the production of fiber-reinforced cement. This method is advantageous not only in that it is highly efficient, but also that when spun fibers such as glass rovings are used as reinforcing fibers, the spinning can be performed extremely efficiently.

Next, examples of the method of the present invention will be described.

First, as a reinforcing fiber bundle, an alkali-resistant glass roving (weighing 2.4' and 9/1000 m), which was made up of 48 strands made up of 100 filaments with a diameter of 15 μm, was used, and as a cement paste. , 50 parts by weight of water per 100 parts by weight of Portland cement, water reducing agent (trade name: Mighty 15 manufactured by Kao Soap)
0) 1.0 to 1.2 parts by weight is used, and while feeding the glass roving at a rate of about 10 m/min, a diameter of approximately 2 crrL is placed at a distance from the glass roving. Cement paste was injected from a 0.5 dragon nozzle.

The discharge pressure of the high-pressure reciprocating pump used for injection is approximately 1o0
ky/ffl, and the discharge amount is approximately 2000 cc/m
It was in.

The glass roving thus assembled with cement is 25crrLX 25CrfLX 6mm
After winding it around a winding plate, the winding plate was removed and flattened so as not to disturb the fiber layer, thereby forming a fiber-cement paste mixed layer.

The number of times the glass rovings were wrapped around the winding plate was 50 times, and the glass rovings were wound around the winding plate so that they were evenly arranged in the same direction.

The fiber-cement paste mixed layer obtained in this way is
The two layers were laminated so that the directions of the glass rovings were perpendicular to each other, and the laminated plate was left in the air for 48 hours after molding, and then cured in water at 20°C for 7 days.

The fiber filling rate of the test piece thus obtained was 12.4% by weight.

FIG. 5 shows a comparative example of the relationship between bending strength and bending strain for the test piece prepared as described above and the test piece obtained by the conventional method using chopped strands.

In addition, this test is based on a three-point bending test, and the number of attempts is 100.
The bending speed was 5 mm/min and the temperature was 20°C.

When the test piece was manufactured by the conventional method, the bending strength was 300 to 9/c-r? Although it is thought that the bending strength is about L or less, it can be seen from the figure that the test piece manufactured according to the present invention has extremely excellent bending strength.

In addition, it was confirmed that these test pieces recovered the bending strain when the bending stress was applied and then removed, and that they had excellent flexibility.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of fiber-reinforced cement manufactured by a conventional method, FIG. 2 is a cross-sectional view of fiber-reinforced cement manufactured by the present invention, and FIG. 3 is a basic configuration for explaining the method of the present invention. 4 is a sectional view showing an embodiment of the apparatus of the present invention, and FIG. 5 is a graph showing the bending strength of a test piece manufactured according to the present invention. 10, 22... Processing tank, 11, 25...
・Cement paste, 13...Reinforcement fiber bundle, 1
4, 34... Nozzle

Claims (1)

[Claims] 1. A fiber bundle made up of a large number of fibers is maintained in a stretched state, a flow of cement paste is injected onto the fiber bundle, and the fiber bundle is opened by the flow of cement paste, and at the same time, the fiber bundle is opened. A method for producing fiber-reinforced cement, which comprises forming fiber-reinforced cement with cement interposed between the fibers by introducing cement paste between the fibers. 2. A guide is installed to continuously feed a fiber bundle made up of a large number of fibers in a stretched state into a treatment tank filled with cement paste, and the fiber bundle is placed under the surface of the cement paste in the treatment tank. 1. A method for producing fiber-reinforced cement, characterized in that a nozzle is provided opposite to the nozzle for injecting a flow of cement paste.