JPS5919746B2 - Spraying method of composition mainly composed of inorganic fibers and hydraulic inorganic binder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a lightweight, fire-resistant material that is mainly made of inorganic fibers such as rock wool, glass fiber, and ceramic fiber, and hydraulic inorganic binders such as Boltland cement, alumina cement, and gypsum. This invention relates to a wet spraying method for forming a heat-insulating and sound-absorbing coating layer.

The purpose of this invention is to easily and freely obtain coated molded products that do not generate dust during spraying, have a bulk specific gravity of 0.4 or less, and are suitable for fireproofing, heat insulation, and sound absorption purposes. Our goal is to provide a construction method that can.

Conventionally, methods for forming a coating layer by spraying can be roughly divided into two methods: dry method and wet method.

In the former (dry type), the dry and mixed materials are conveyed by air through a transport pipe, and are discharged from a spray nozzle.Water is also sprayed out in the form of a mist from a separate water fountain installed around the nozzle, allowing the materials and water to intersect. The latter method (wet method) involves adding water to the dry mixed materials, kneading them, transporting them through a transport pipe with a pump, and spraying them with compressed air at the spray nozzle. be. Each method has its advantages and disadvantages; the former (dry method) has a lighter bulk specific gravity of the molded product, 0.15 to 0.3, and is therefore cheaper to construct than the latter. Cheap, but on the other hand
The generation of dust is unavoidable, which poses a problem from the viewpoint of pollution prevention and occupational health.The latter, on the other hand, does not generate dust, but the bulk specific gravity of the molded product is between 0.4 and 0.8, which increases construction costs. The problem was that it was bulky.

Therefore, the present inventors conducted many experiments and studied the conventional methods, and found that conventional methods have been difficult due to the nature of inorganic fibers, which have low water retention and tend to separate from the blended water. We made it possible to wet pump conveyance of inorganic fibers alone, and further research progressed by adding water and surfactants to inorganic fibers, mixing them, adding thickeners as necessary, and reducing the amount of introduced air. An inorganic fiber slurry whose specific gravity has been adjusted according to the quantity, and a hydraulic inorganic binder slurry whose concentration has been adjusted by adding water to a hydraulic inorganic binder and mixing them, and adjusting the concentration by adding a thickener as necessary, are separately prepared. They came up with a construction method in which the materials are transported by a pump through a transport pipe, mixed at a nozzle, and then spray-molded using compressed air.

In other words, since this method is a wet method, there is no generation of dust, and by easily changing the specific gravity and concentration of the slurry, as well as the flow rate of each slurry when mixing at the nozzle, these specifications can be improved. With the combination of , the bulk specific gravity is 0.
Since it is possible to easily and freely obtain a coated molded product having a material composition and a bulk specific gravity of 4 or less depending on the purpose of fire resistance, heat insulation, and sound absorption, it is an extremely useful and effective method that combines the advantages of conventional methods. This is a new construction method that has a wide range of uses.

The present invention will be explained in further detail. Weight ratio of 1 to inorganic fiber
50-300% water and 1-3% weight ratio to this water
When adding a surfactant and kneading it with a mixer, and when the transport distance is long and the transport resistance due to the pump is large,
A slurry is prepared by adding a thickener in a weight ratio of 0.1 to 0.5% to water and introducing fine bubbles with an air content of 40 to 80%.

In this case, the amount of water added to the inorganic fiber should be increased or decreased depending on the type of fiber, taking into account the water retention rate of the fiber in its normal state.For example, in the case of rock wool, it should be 200 to 250%. preferable. Further, the purpose of the thickener is to further stabilize and strengthen the introduced bubbles, and it may be added depending on the capacity of the pump and the transport distance. The slurry prepared in this way has a larger amount of water in relation to the amount of inorganic fibers within the range of its normal water retention rate than slurry j obtained by conventional wet spray coating molding, and has a higher surface activity against water. Since the amount of agent added is extremely large, combined with the presence of a large amount of strong and stable air bubbles due to the surfactant, the fluidity of the slurry is high, and the air bubbles do not disappear even during movement in the transport pipe and discharge. Because there is no such thing, stable pump transport is possible.

On the other hand, if 100 to 200% water by weight is added to the hydraulic inorganic binder and mixed in a mixer, and if there is a risk of separation and sedimentation of the hydraulic inorganic binder and water during transportation, the water A slurry is prepared by adding a thickener in a weight ratio of 0.1 to 0.3%.

The surfactant mentioned here has good bubble stability because it introduces a large amount of bubbles, and the surfactant and thickener both inhibit the effect when mixed with the hydraulic inorganic binder. Of course, this should not be the case.

The inorganic fiber slurry and the hydraulic inorganic binder slurry prepared in this way are transported separately through a transport pipe using a pump, are mixed together at a spray nozzle, and are spray-molded using compressed air. It is something to do.

As mentioned above, this invention can increase the fluidity of the slurry by creating a large amount of strong and stable air bubbles by introducing a surfactant and air, so that air bubbles can be prevented even during movement in the transport pipe and discharge. Since it does not disappear, stable pumping is possible, and since there are many bubbles, it does not damage the inorganic fibers.Also, since the inorganic fibers spread flat and are well intertwined, the coated molded product that is spray-molded with compressed air can solidify and harden. The cracks that sometimes occur can be eliminated.

The inorganic fiber slurry may be prepared as a slurry by adding fire-resistant inorganic aggregate such as pearlite, vermiculite, mica, silica sand powder, etc. at a weight ratio of 40% or less to the inorganic fiber. A coated molded article can be obtained in which the material is part of the composition, or a slurry may be prepared by adding a water-soluble alkaline substance such as caustic soda or caustic potash together with water. In this case, the hydraulic inorganic binder and Co-mixing can be used to accelerate chemical hardening, and inorganic hydrates such as borax aluminum hydroxide can also be added to further improve the fire resistance of the coated molding.

Such a similar application can also be applied to hydraulic inorganic binder slurry, and the confluence and mixing of the slurry at the nozzle part can also be done within the nozzle body.
There is no problem whether it is placed before or after the nozzle. That is, it is clear that various applications can be added without departing from the spirit of the present invention, and even if these applications are added, the effects of the present invention will not be impaired.

Next, examples will be given of the coated molded products of this invention.

Example 1 0 rock wool, water with a weight ratio of 250% of the rock wool, a surfactant with a weight ratio of 1% with respect to water, and a thickener with a weight ratio of 0.4% with respect to water were added and mixed in a mixer. Knead with
An inorganic fiber slurry with a bulk specific gravity of 0.26 into which 70% of the air content was introduced was prepared, and then Portland cement and water with a weight ratio of 150% of the Portland cement were added and mixed in a mixer to form a hydraulic inorganic fiber slurry with a concentration of 40%. The binder slurry was prepared.

Each slurry is transported through a conduit using a snake-type pump, and the flow rate is adjusted so that the amount of inorganic fiber slurry and hydraulic inorganic binder slurry is 5:1 just before the nozzle, mixed together, and sprayed with compressed air. I did the molding.

The dry bulk specific gravity of the obtained molded product was 0.23, and the weight ratio of the inorganic fibers and hydraulic inorganic binder to the spray molded product was approximately 4:6, and the mixed state of each was good in appearance. It was hot.

Example 2 Using the slurry of Example 1, the flow rates were adjusted so that the ratio of the inorganic fiber slurry to the hydraulic inorganic binder slurry was 8:1, and the mixture was mixed and spray molded in the same manner.

The dry bulk specific gravity of the obtained molded product was 0.17, and the weight ratio of the inorganic fibers and hydraulic inorganic binder to the spray molded product was approximately 5:5, and the mixed state of each was determined by the appearance. It was in good condition.

Example Weight ratio of 30 Tsuku wool to Rock wool 20
0% water, a surfactant with a weight ratio of 2% to the water, and a thickener of 0.3% to the water were added and kneaded in a mixer, and 40% of the air amount was introduced. Prepare an inorganic fiber slurry with a bulk specific gravity of 0.45, and mix it with a mixer by adding Portland cement, water with a weight ratio of 100% of Portland cement, and a thickener with a weight ratio of 0.2% to water. A hydraulic inorganic binder slurry having a concentration of 50% was prepared.

Each slurry is conveyed through a conduit using a squeeze pump, and the flow rate is adjusted so that the amount of inorganic fiber slurry and hydraulic inorganic binder slurry is 5:1 just before the nozzle, mixed together, and sprayed with compressed air. I did the molding.

The dry bulk specific gravity of the obtained molded product was 0.35, and the weight ratio of the inorganic fibers and hydraulic inorganic binder to the spray molded product was approximately 5:5, and the mixed state of each was good in appearance. It was something.

Example 4 Using the slurry of Example 3, the flow rate was adjusted so that the ratio of the inorganic fiber slurry to the hydraulic inorganic binder slurry was 10:1, and the mixture was mixed and spray molded in the same manner.

The dry bulk specific gravity of the obtained molded product was 0.28, and the weight ratio of the inorganic fibers and the hydraulic inorganic binder to the spray molded product was approximately 6:4, and the mixing state of each was determined by the appearance. It was in good condition.

Claims (1)

[Claims] 1 Mix inorganic fibers with water and a surfactant, and add a thickener if necessary to make a slurry with an air content of 40~
A slurry prepared by introducing 80% fine air bubbles and a slurry prepared by adding water to a hydraulic inorganic binder and adding a thickener as necessary are separately transported into a transport pipe. A composition mainly composed of inorganic fibers and a hydraulic inorganic binder, which is transported by a pump, mixed together at a spray nozzle, and spray-molded using compressed air. spraying method.