JP2000343434A - Blasting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To positively perform paint film separation, grain raising, descaling, and the like of an exterior wall of a building structure or the like and to dispense with secondary treatment to simplify work by using sodium bicarbonate of specific grain size as blasting material. SOLUTION: Sodium bicarbonate of about 0.2-5 mm in grain diameter is sprayed as blasting material with high pressure water or high pressure air to apply grinding/polishing/cleaning, washing, grain raising and paint film separation to the surface of concrete, stone or a metal plate. If the grain diameter of sodium bicarbonate is about 0.2 mm or less, it is too fine to obtain sufficient blasting effect, and if it is about 5 mm or more, a treated object is damaged because impact force is strong, and there is the possibility of blocking a nozzle, and moreover equipment is enlarged. Sodium bicarbonate is white monoclinic crystalline powder which is a safe substance to a human body, mainly used for the medicinal powder for the stomach and other additives as medicine or as edible baking powder or the like, and easily soluble in water, insoluble in alcohol and decomposed by heating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blasting method for surface treatment using baking soda, and more particularly, to a coating applied to an exterior surface of a relatively hard building structure such as concrete or a metal plate. The present invention relates to a blasting method capable of cleaning and polishing without cleaning or peeling, or cleaning or polishing natural stone structures, or damaging relatively soft or brittle materials such as aluminum products and synthetic resin products.

[0002]

2. Description of the Related Art Conventionally, for example, when a coating film on an outer wall of a building structure or the like is stained, swelled, cracked, etc. over a long period of time, the coating film is peeled off for repair work. , Or when removing rust generated on the wall or the like, the existing coating film is removed in various ways according to the type of coating film and various conditions, and these removal methods are as follows. There is a way.

A blaster that blows blast material with high-pressure air
Add a small amount of water to the id blast method and drive blast method.
Wet blasting method to mix at tip of whirlpool, high-pressure jet water
Blast material and high pressure jet water suction effect at the tip of the nozzle.
Water blast method to mix using. Motor shaft
Attach a disc to this, and take a cutter or cloth file
Sander method using a disc sander attached. 3
00-1000kgf / cm ^TwoHigh-pressure waterworks that inject pressure water
Law. 1000 to 2500 kgf / cm^TwoInject pressure water
Ultra high pressure water method. Apply a release agent containing methylene chloride
After that, a stripper is used to remove with a screver. Ultrasonic
Attach a blade to the end of the cord extending from the oscillator, and
There is an ultrasonic method and the like performed by vibration.

[0004]

However, in the case of the dry blast method, silica sand mixed with high-pressure air and sprayed hits the surface to be peeled, and dust is generated. In addition, there is a problem that the quality deteriorates and the health of the worker is impaired. In addition, the silica sand hitting the surface to be peeled may adhere and remain as it is, so that it has to be flushed with water. Therefore, it is sometimes performed by the drive-last simultaneous suction method, in which the silica sand strikes and collects at the same time, but this method uses silica sand sent by high-pressure air.
Since it is absorbed and collected at the same time as discharge, the generation of dust and the like is small, but the work efficiency is poor. In addition, the silica sand that has fallen on the surface to be peeled must be swept away, absorbed by vacuum, or washed away by water, etc. In addition, silica sand washed away by water must be collected from the meeting place. A great deal of effort and expense had to be spent on this recovery and the processing of the recovered silica sand for industrial waste.

[0005] In the case of the wet blasting method, the blast material is sprayed together with high-pressure air and a small amount of water. In the case of the water blasting method, since the blasting material is sprayed together with the high-pressure water onto the object to be blasted, the generation of dust is small. A secondary treatment facility is required to collect and treat the blast material containing water that has been sprayed and dropped, which increases the treatment cost, requires a space for installing the treatment facility, and requires a long working time. There was a problem that it took a long time.

[0006] The particle size of the blast material in such a blasting method has been, until now, silica sand No. 8 ... about 210 to 150 microns Silica sand No. 7 ... about 145 to 212 Micron silica sand No. 6 Approx. 180-300 micron Silica sand No. 5 Approx. 300-550 micron Silica sand No. 4 Approx. Approximately 0.4 to 1.2 mm Phosphoric acid chemicals Approximately 175 to 290 microns, but silica sand, garnet sand, alumina, etc. are used. , Dust, recovery, industrial waste treatment, etc., ion exchange resin, phosphoric acid-based chemicals, ammonia-based chemicals, etc., have chemical properties that greatly affect the blast action,
There were problems such as drainage and remaining on the blast surface, and it took time and money to solve the various problems.

[0007] In the case of the sander method, it is often used to remove a small area of a coating film, but is not suitable for removing a wide area of the coating film.
Not only is work efficiency extremely poor, but loud noise is generated,
In addition, there is a problem that a large amount of dust scatters and floats as in the case of dry sand blasting, which deteriorates the environment.

[0008] In the case of the ultra-high pressure water method, even if it is suitable for filing and cutting work, the pressure is too strong and the substrate is easily damaged more than necessary. If the substrate is damaged, it takes time and money to repair and repair the work. However, there is a problem that it requires skill and increases the danger of workers.

In the case of the stripper method, an organic solvent harmful to the human body is contained, and the peeled coating residue and waste liquid must be properly treated as industrial waste. Treatment was required and acid and alkaline wastewater had to be neutralized before draining. Furthermore, the paint remover is applied with a brush or a low-pressure airless spray.However, during work, rubber gloves, protective glasses, etc. are used so that the paint remover does not adhere to skin or clothes.
You must wear protective equipment such as an apron.
There were hygiene issues.

[0010] In the case of the ultrasonic method, the width of the blade in contact with the working surface is as narrow as 1 to 5 cm, so that there is a problem that a step is easily formed on the peeling surface and the working efficiency is poor.

On the other hand, the body of a vehicle, the body of an aircraft or a returnable box for carrying synthetic resin products such as beer, drinking water, foodstuffs and the like made of aluminum or an aluminum alloy having a relatively soft surface are blasted with the above-mentioned blast material. Then, it was too powerful and could not be used because it damaged the surface.

In particular, the returnable boxes made of synthetic resin molded articles are stacked and transported, so that the frames on the upper and lower peripheral surfaces are damaged in a short period of time, and when rust and dirt are generated. Because we have food,
It is unfavorable in terms of hygiene and is discarded as industrial waste, causing environmental pollution.

The present invention has been developed with the object of solving the above-mentioned problems, and is intended for cleaning, polishing, roughening, peeling off coatings, aluminum products, aluminum alloy products and composites of exterior surfaces of various building structures. The purpose is to provide a blasting method that considers the global environment that is suitable for environmental protection that does not require wastewater treatment, while relatively soft or brittle materials such as resin products can be recycled and reformed by blasting work. is there.

[0014]

Means for Solving the Problems As means for solving the above-mentioned problems and achieving the object, the present invention relates to a method for solving the above-mentioned problem.
Blasting method using baking soda with a particle size of as a blast material and spraying it with high-pressure water or high-pressure air to clean, wash, roughen, and peel off the surface of concrete, stone, metal plates, etc. And adopted.

Further, the present invention is characterized in that fine powdered sodium bicarbonate is dissolved in water in a suspended state, and the suspension is sprayed with high-pressure water or high-pressure air to clean and polish the surface of the object. The blast method was developed and adopted.

Further, according to the present invention, there is provided a blasting method comprising the above-mentioned blasting method, wherein the particle size of baking soda is 10 to 120 microns, and the object is an aluminum product, an aluminum alloy product or a synthetic resin product. A blast method was developed and adopted.

[0017] Here, baking soda is also known as bicarbonate soda, which is mainly used for gastric powder and other additives for medical use, or safe for human body used for baking powder and the like for food. A substance that is a white, monoclinic, crystalline powder that is easily soluble in water, insoluble in alcohol, and decomposes when heated.

The size of the baking soda is preferably in the range of 0.2 to 5 mm when used for peeling off a coating film when the object is relatively hard, such as concrete, stone, metal plate, etc. I have. We choose thing of this range depending on condition, but are 0.2mm
If it is below, it is not suitable because it is too fine and a sufficient blasting effect cannot be obtained.On the other hand, if it is more than 5 mm, the impact force becomes strong and the workpiece is damaged, and the nozzle may be blocked, and the equipment is large. Not suitable for becoming.

When a relatively soft object such as an aluminum product, an aluminum alloy product, a polypropylene resin or a polyethylene resin product is polished or polished, a fine baking soda having a particle size of 10 to 120 microns is used. Dissolve in water and use. If it is less than 10 microns outside this range, it is unsuitable because it is too fine and a sufficient blast effect cannot be obtained, while if it is more than 120 microns, the impact force becomes strong and the workpiece is damaged. Limited.

The pressure of the high-pressure air for blowing sodium bicarbonate having a particle size of 0.2 to 5 mm with high-pressure air is 2 to 7 kgf /
is suitable in the range of cm ^2, 2kgf / cm ² or less to become the impossible released cleanly and be uneven coated surface, and not suitable since the time-consuming, whereas, damage the underlying exceeds 7 kgf / cm ² Easy and if spraying with high pressure water, 300
Range ~1000kgf / cm ² is suitable. 300kgf
/ Cm ² or less is not suitable because the coating film surface becomes uneven and cannot be peeled cleanly and it takes time.
If it exceeds 000 kgf / cm ² , the substrate is easily damaged, and it takes time and money to repair and correct it.

As the sodium bicarbonate suspension used in the form of a suspension dissolved in water, a solution prepared by dissolving 1.2 to 3 kg of sodium bicarbonate having a particle size of 10 to 120 microns in 1000 cc of water is suitable. I have. The high-pressure water preferably has a temperature in the range of 40 to 95 ° C., and the hot water in this range is determined according to various conditions. The solubility of baking soda also worsens and remains undesired, making it unsuitable.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described. (Example 1) An undercoat of reinforced concrete was coated with an acrylic resin paint (TOMASTIC C SEALER (trade name) manufactured by Tope Co., Ltd.) as an undercoat paint at a coating amount of 0.13 kg / m ² by roller coating once, and the main material was applied. The main material of Toamastics C (trade name, manufactured by Tope Co., Ltd.) is applied once with a porous roller at an application amount of 2.0 kg / m ² , and as a top coat, the cosmetic finish of Toamastics C (trade name) (trade name) ( 0.1%
A baking soda having an average particle size of 1.5 mm was used as a blast material on the surface of the coating film coated once with a roller at an application amount of ² kg / m ² , a pump pressure of 500 kgf / cm ² and a water pressure of 35 l / l.
Minute, the diameter of the nozzle to be used is 1.4 mm, and the distance from the surface to be processed is 1
The spray was performed under the conditions of 5 cm and an angle of 90 degrees between the nozzle and the surface to be processed.

(Example 2) A synthetic resin emulsion (diaskin (trade name) manufactured by Tsuneka Chemical Industry Co., Ltd.) was sprayed on a reinforced concrete base with a spray gun at an application amount of 0.10 kg / m ^2. After drying, the same paint was sprayed at a coating amount of 2.6 kg / m ^{2 on} the coating surface under the same conditions as in Example 1.

Example 3 On the inner surface of a concrete pool,
Epoxy resin paint pool color # 3000 (product name)
The product of Shinto Paint Co., Ltd. was applied once with a roller at an application amount of 0.13 kg / m ² , dried, and then sprayed again on the coating surface coated under the same conditions under the same conditions as in Example 1. .

The test results of Examples 1 to 3 are shown. As a test method, 1 m ² of peeling was repeated three times to obtain an average time. Example 1 is 7 minutes and 49 seconds, and Example 2 is 4 minutes and 22 seconds.
Seconds and Example 3 was 4 minutes and 06 seconds.

(Example 4) For 1000 cc of water, 10
A sodium bicarbonate suspension having a concentration of 1.5 kg of sodium bicarbonate pulverized to ２０20 microns is dissolved in the suspension at a discharge pressure of 150 kgf / cm ² and a water volume of 1 kg.
Water blast (self-priming 0.8 kg / min) using a hot water of 6 liters / minute and 80 ° C., a beer case (length 30 cm, width 28 cm) molded from Sasakure's polypropylene resin generated on the upper peripheral frame , 2.5 cm wide and 27 cm high).

After projecting for 1 minute and 45 seconds, the state of the beer case was observed. The sasacre formed on the upper peripheral frame was completely removed, and the appearance became beautiful with the dirt removed and polished.

(Example 5) For 1000 cc of water, 10
A sodium bicarbonate suspension having a concentration of 2.0 kg of sodium bicarbonate pulverized to a size of about 20 microns was dissolved in the suspension at a discharge pressure of 200 kgf / cm ² and a water volume of 1
Water blasting (self-priming type 1.1 kg / min.) Using hot water of 6 liters / min. And 80 ° C., the lower half of a body of aluminum car body with black streaks (iron sulfide) and dirt (length 10)
4 cm, 8.5 m wide).

After the projection was completed for 27 minutes and 50 seconds, the body of the aluminum body was observed, and it was found that the portion where the black streaks (iron sulfide and oils and fats) had adhered had been completely removed. It was much quicker and easier than polishing with a compound or the like or washing with an alkaline and acidic detergent.

Although the present invention has been described with respect to the peeling and dirt of the coating film surface in the above embodiment, the present invention is not limited to these, and can be used for operations such as rust removal, polishing, polishing, and blinding. Of course, various changes can be made without departing from the scope of the present invention.

[0031]

As described above, according to the blasting method of the present invention, since baking soda having a particle diameter of 0.2 to 5 mm is used as a blasting material, peeling of a coating film on an outer wall surface of a building structure or the like can be prevented. Roughening, rusting, etc. can be surely performed, and secondary processing such as sweeping after injection, recovery by vacuum, draining water and collecting at a meeting place etc. when using a solid material such as conventional silica sand is eliminated. The operation can be simplified, and the number of workers and time can be greatly reduced.

Further, baking soda is used in foods and medicines, is good for safety and health without any adverse effect on the human body, and is suitable for environmental protection. It can be used for baking molds and cleaning large fryers on the net.

Further, the present invention makes it impossible to obtain relatively soft aluminum products, aluminum alloy products, synthetic resin products, etc. by projecting a suspension of fine powdered sodium bicarbonate suspended in water. Blasting of soft and brittle materials that were previously used can recycle and renovate what has been disposed of in the past, making effective use of resources and economical, as well as preventing environmental pollution and protecting the global environment. It is useful for.

Claims (4)

[Claims] 1. Baking soda having a particle size of 0.2 to 5 mm as a blast material and spraying it with high-pressure water or high-pressure air to clean, wash, roughen the surface of concrete, stone, metal plate, etc., and peel off the coating film Blasting method characterized by doing. 2. A blast method comprising dissolving fine powdered sodium bicarbonate in water in a suspended state, and spraying the suspension with high-pressure water or high-pressure air to clean and polish an object. 3. The blast method according to claim 2, wherein the particle size of the baking soda is 10 to 120 microns. 4. The blast method according to claim 2, wherein the object is an aluminum or aluminum alloy product or a synthetic resin product.