JPH09242347A - Peeling-off method by high pressure hot water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently peel off the surface of a building structure and reduce the construction period and cost, by spraying high pressure hot water with a specified delivery pressure, water volume, and temperature, from a gun. SOLUTION: When the water temperature is lower than 60 deg.C, the permeability or the melting property of a paint becomes unfavorable and when it is higher than 90 deg.C, water becomes vapor and scatters and it can not reach the painted surface. And hence, the water temperature is kept to be whithin 60-90 deg.C. When the delivery pressure of the hot water is lower than 450kgf/cm<2> , the painted surface becomes uneven and when it is higher than 800kgf/cm<2> , the substrate becomes apt to be damaged. And hence, the delivery pressure is kept to be within 450-800kgf/cm<2> . High pressure hot water as much as 30-55lit./min is jetted out from the spray nozzle of a gun to peel off the painted surface of a building structure or slacken the surface. In this way, the expenditure can be reduced without repair of the substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to the formation of fine irregularities on a base in order to improve the adhesion of a paint when peeling off an old exterior coating film surface such as a building structure or applying a coating. The present invention relates to a high-pressure hot water peeling method used for roughening work.

[0002]

2. Description of the Related Art Conventionally, for example, when a coating layer on the outer wall surface of a building structure is soiled or cracked, an old coating layer is peeled off, or when rust formed on the outer wall surface is removed, or Dry sand blasting method or wet blasting method that sprays the blast material with compressed air or high-pressure water on the surface of the coating film during roughening, etc. The construction method is carried out.

As other methods, a disk sander method in which a disk is attached to a motor shaft and a cutter or a sand file is attached to the disk, a sander method in which a release agent containing an organic solvent is applied, and 1000 to 2000 kgf There is also a method of using an ultra-high pressure water method in which water is sprayed at a pressure of / cm ² .

[0004]

However, in the case of the dry sand blasting method, silica sand radiated by being mixed with compressed air hits the surface to be treated to generate dust and the dust scatters, so that the working environment is In addition to the problem that it deteriorates and the health of the worker is impaired, the silica sand that hits the surface to be treated may remain adhering to it as it is. In some cases, this method absorbs and collects the blast material sent by compressed air pressure at the same time as it is discharged, so that dust or the like is less generated, but the work efficiency is poor. In addition, the silica sand that has fallen on the surface to be treated must be swept, absorbed by vacuum, washed with water, etc., and the silica sand washed with water must be collected from the hall. , I had to spend a lot of time and effort on this recovery.

In the case of the wet blasting method, since the blast material is radiated to the surface to be treated together with the high pressure water, dust is rarely generated, but for the purpose of recovering and treating the blast material containing the radiated and dropped water. There is a problem that a treatment facility for secondary treatment is required, the treatment cost becomes high, the pace of treatment facility needs to be installed, and the working time is long.

In the case of the sander method, not only the working efficiency is remarkably poor, but also a large amount of noise is generated, and a large amount of dust scatters and floats similarly to the dry sandblast method, which deteriorates the environment.

In the case of the stripping agent construction method, an organic solvent harmful to the human body is contained, and the stripped coating dust and waste liquid must be legally treated as industrial waste, and washing water is drained. The acid and alkaline wastewater had to be neutralized before draining. In addition, the coating film remover is applied with a brush or a low pressure airless spray, but at the time of work, in order to prevent the film remover from sticking to the skin or clothes, use rubber gloves, protective glasses, aprons, etc. Protective equipment had to be worn, and there were safety and hygiene problems.

In the case of the ultra-high pressure water method, the pressure is too strong and the base material is easily damaged more than necessary. If the base material is damaged, it takes time and money to repair and repair the work. There was a problem saying that it would increase.

The present invention was developed with the object of solving the above-mentioned problems. It does not cause pollution due to dust and noise, does not hinder safety and hygiene, and damages the substrate more than necessary. It is an object of the present invention to provide a high-pressure hot water stripping method with good work efficiency.

[0010]

Means for Solving the Problems As a means for solving the above problems and achieving the object, the present invention provides a discharge pressure of 450 k.
Characteristic of peeling off the surface of the object by spraying high-pressure hot water of gf / cm ^{2 to} 800 kgf / cm ² , water volume of 30 liters / minute to 55 liters / minute, and water temperature of 60 ℃ to 90 ℃ from the gun The high pressure hot water stripping method was developed and adopted.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the embodiments of the present invention will be described. High-pressure hot water is supplied to the jet nozzle of a spray gun and jetted from the jet nozzle to peel off the coating surface of a building structure or the like. The work is done or roughening is performed.

The hot water used here is preferably one having a temperature in the range of 60 ° C to 90 ° C. The water within this range is determined according to the conditions, but if it is below 60 ° C, the penetrability and the melting property of the paint are poor. It is not suitable because it becomes water vapor at 90 ° C or higher and cannot be sprayed to the surface of the coating film.

Further, the pressure for discharging hot water is 450 kgf / cm ²
~ 800kgf / cm ² is not suitable when it is less than 450kgf / cm ^{2 because} it causes unevenness on the surface of the coating film and it cannot be peeled off cleanly, and it takes time. On the other hand, when it exceeds 800kgf / cm ^2. However, the base is easily damaged, and it takes time and cost to repair and repair the base, which is preferable and is limited to the above range.

The amount of water is preferably 30 liters / minute to 55 liters / minute. The reason is that below 30 liters / minute,
This is because the impact force is weak and the peeling effect is not sufficient, and when it exceeds 55 liters / minute, it is not possible to accurately spray onto the spray surface with a spray gun, especially at construction sites where the scaffolding is poor. Because it could not be used.

[0015]

EXAMPLE A specific example of the present invention will be described below. Using a pump having a discharge pressure of 500 kgf / cm ² and a water amount of 35 liters / min (C-153 hot water specification manufactured by Arikou Kogyo Co., Ltd.), 7
Acrylic resin sealer is applied to the concrete base under the condition that the interval between the surface to be treated is 15 cm, using a fan-shaped nozzle with a nozzle diameter of 1.06 mm and an injection angle of 7 degrees with warm water at 0 ° C.
20m ² coating surface with acrylic resin paint applied on top
When the peeling work was performed, 80% could be peeled off in 1 hour and 17 minutes, and the remaining part could be peeled off in 46 minutes.

(Comparative Example) When the water temperature in the above example was changed to tap water temperature (normal temperature water) and the other conditions were the same as those in the above example, 75% peeling was possible in 3 hours. However, the place where the coating film was alive (the degree of adhesion was good and the deterioration of the coated surface did not occur much) remained in the middle.

As is clear from the above, it can be seen that hot water is superior in workability to normal temperature water. In the case of peeling with normal temperature water, when the pressure is 450 kgf / cm ² or more compared with warm water, 1.4 to 5.6 times the pressure is required for the same amount of water.

[0018]

As described above, according to the high pressure hot water stripping method of the present invention, the discharge pressure is 450 kgf / cm ^{2 to} 800 kgf / cm ² , and the amount of water is
30 liters / min to 55 liters / min, high-temperature hot water with a water temperature of 60 ° C to 90 ° C is sprayed from a gun to peel off the surface of the object, so the properties of the paint with respect to the temperature,
Efficient stripping is possible in combination with the solubility / permeability of warm water and an appropriate pressure and amount of water. In addition, when performing work relying on pressure in conventional room temperature water, it is necessary to damage the base material and spend time and money for repair and repair. It is possible to reduce the cost and cost.

Claims (1)

[Claims] 1. A discharge pressure ^{450kgf / cm 2 ~800kgf / cm 2} , water 30 l / min to 55 l / min, and sprayed from spray gun high pressure hot water temperature 60 ° C. to 90 ° C., of the object A high pressure hot water peeling method characterized by peeling the surface.