JPS59160577A - Cleaning method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cleaning method for removing surface deposits adhering to an object to be washed by jetting a jet of fluid. More specifically, the present invention relates to a method of cleaning an object by jetting a fluid containing soft solid particles so as not to deform or change the surface of the object.

Conventionally, there have been stains that have adhered to objects to be cleaned that cannot or are difficult to clean using only water and the dissolving power of detergents, organic solvents, and the like. In addition, these stains do not simply adhere to the surface of the product, but may also adhere firmly to the surface of the item to be washed due to the pressure and heat received during processing or the roughness of the surface of the item to be washed. Ta. For example, when applying a hairline finish to the surface of a stainless steel plate press product, a mixture of oil and fat and an abrasive material such as alumina is used as a puff agent. Stainless steel is a sticky material, but the processed parts are hardened and hardened, and in order to improve processing efficiency, continuous polishing requires strong mechanical polishing. In addition, fine polishing powder is used to create a glossy hairline finish, so the polishing powder digs into the uneven parts of the stainless steel surface.

It becomes a surface deposit and adheres to the surface together with the oil and fat.

In order to remove such insoluble surface deposits or surface deposits firmly attached to the object to be washed, a conventional cleaning method involves spraying an aqueous solution containing an alkali and a surfactant onto the object under high pressure. is being carried out. However, this method has the problems of staining of the washed material due to the aqueous solution generated during the drying process and contamination of rivers due to a large amount of wastewater containing oil.

In order to solve these problems, we have developed a method of spraying the object to be washed at high pressure using only a solvent instead of detergent water, and a method of immersing the object in the solvent and applying ultrasonic waves. A method of cleaning is used. However, these methods
There is a drawback that the cleaning effect is not sufficient, and in particular, it is not possible to completely remove surface deposits stuck to the rough valleys where the surface treatment has been performed.

There is also a method of cleaning by applying mechanical scraping force directly to the object to be washed using a brush, etc. However, if the structure of the object to be washed is complex, the structure of the machine may become complicated and the cleaning method may occur during cleaning. be.

In order to avoid this problem, cleaning methods such as liquid honing have been used, but the solid material used as the abrasive material is too hard, or the cleaning fluid is ejected using pressurized air or high-pressure water of iokg/Cl112G or more as the driving source. Since cleaning is performed by colliding with the object, it is impossible to clean the object without changing its surface.

The present invention was developed as a result of research to overcome the shortcomings of the conventional methods, and as a result of the present invention, it is possible to remove liquid and soft solid particles by applying a driving source to the object to be washed, which has a smooth or rough surface. The present invention was developed based on the knowledge that by spraying a specific jetting fluid containing the cleaning material, it is possible to completely remove surface deposits without damaging or polishing the surface of the object to be washed. It is.

That is, in the present invention, a jetting fluid containing a liquid and soft solid particles is jetted onto the surface of the object to be washed at a jetting pressure of at least 0-3 kg/cra''G using the liquid as a driving source to remove surface deposits. This is a cleaning method characterized by the following.

Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 1 is an explanatory diagram showing one example of the cleaning method of the present invention, and FIG. 2 is an explanatory diagram showing a cleaning process.

Nozzle 1, ejected fluid population 2, gas population 3, and gun body 4
A jetting fluid 8 containing a liquid 6 and soft solid particles 7 is jetted from a nozzle 1 of a jetting gun 5 onto the surface of an object 9 to be washed which has been surface-treated.

Soft solid particles 7 contained in the jetted fluid 8
collides with surface deposits 15 consisting of abrasive powder 10 and oil 11 adhering to the smooth surface or rough or uneven surface of the object 9 shown in FIG. 2(a). As shown in b), the dirt layer on the surface is destroyed and spread, and some soft solid particles penetrate the surface of the object to be washed, and some of the soft solid particles are attached to their protrusions or to the smooth or uneven surface of the object to be washed. It deforms and bites into the roughness of the surface and removes the surface deposits stuck to the smooth surface or the four parts, and some soft figurine-shaped grains are crushed into the roughness of the convex part of the surface. However, since the hardness of the soft solid particles is smaller than that of the object to be washed, the soft solid particles are only deformed, and the convex portions are not deformed or polished, so that the object can be washed without damaging the surface of the object.

By further rinsing, the surface of the object to be washed is completely cleaned as shown in FIG. 2(c). The solid roughly mixed waste liquid 13 that has been cleaned is collected in the collection tank 12 and is sent to the injection gun 5 as a jet fluid by the circulation pump 14.
supply to

The cleaning method of the present invention can be carried out either batchwise or continuously.

The objects to be washed to which the present invention is applied are mainly surface-treated products, such as metals, on which surface deposits made of liquid, solid, or a mixture thereof are adhered.
It is made of inorganic substances, resins, etc. The surface deposits on the object to be cleaned consist of oil and fat, inorganic substances such as abrasive powder, mixed components thereof, and other components of the object to be cleaned. Specific examples include super finishing and lapping. Polishing slag after processing (surface roughness IS or less), grinding slag after mirror grinding (surface roughness IS approximately), honing (surface roughness IS ~ 3)
8) Polishing slag after polishing, polishing slag after barrel polishing, polishing slag after hairline processing or puff polishing for pre-plating treatment,
Machinability after cutting, stains on painted, lining or coated products, stains on glass ceramics, stains on printed products, stains on electronic material parts, radioactive contaminants, and stains on printed circuit board resin printing plates after exposure. Examples include cured resin, the surface of the printed circuit board to be etched before the etching process, and unnecessary deposits after the etching process.

In the present invention, the ejected fluid ejected onto the surface of the object to be washed is a fluid containing a liquid mixed with gas and soft solid particles as required, and the liquid is used as a driving source.

A liquid is used as a dispersion medium and an acceleration medium for soft solid particles, and a specific example is 1.1,1-)! J
Rhodanized hydrocarbon solvents such as chloroethane, trichlorethylene, perchlorethylene, carbon tetrachloride, methylene chloride, 1.1.2-)dichloro-1,2,2-trifluoroethane, petroleum, benzene, gasoline , hydrocarbon solvents such as toluene and xylene, alcohol solvents such as inpropyl alcohol, N-butanol and methyl alcohol, ketone solvents such as acetone and methyl ethyl ketone, and other ester solvents, or mixtures thereof. , water and an alkali, a mixture of water and a detergent such as a surfactant, and the like. Among these, the solvent is preferable for cleaning surface deposits containing oil and fat, such as polishing slag that has been subjected to surface treatment such as polishing.

Soft solid particles are used that have specific physical properties, and the average particle size of the solid particles varies depending on the surface roughness of the object to be washed and the state of dirt adhesion, but the specific particle size range is 5 to 5. 500
[mu], preferably 30 to 300[mu]; if it is less than 5[mu], the collision force will be weak and the cleaning effect will be low; if it exceeds 500[mu], it will be difficult to penetrate into the recesses on the surface of the object to be washed. The hardness should be soft, less than the hardness of the object to be washed, preferably 1/3 to 1/20 of the hardness of the object to be washed, so that the surface of the object to be washed can be cleaned without polishing or damage. Specifically, it is suitable for HR on stainless steel SUS plate with AsTMD785.
Preferably, M is within 200.

The specific gravity should be heavier than the liquid used, preferably at least 1.1 times the specific gravity of the liquid; if it is light, it will follow the liquid and collide with the items to be washed, resulting in the desired cleaning effect. I can't do it. Note that if the liquid contains gas, the specific gravity may be lighter than the liquid.

The shape can be spherical, polygonal, irregular, or the like. Other properties include impact resistance and abrasion resistance, continuous heat resistance temperature is higher than the liquid temperature used, embrittlement temperature is lower than the liquid used, and chemical resistance against the liquid used and surface deposits. It is preferable that the material has good properties and solvent resistance.

Soft solid particles that satisfy the various physical and chemical properties listed above are appropriately selected and used depending on the relationship between the items to be washed, surface deposits, and the liquid used, but specifically, plastic, walnut, Rubber, sponge, animal hair cut products, etc. are used, and among these, general-purpose materials include unsaturated polyester, melamine, epoxy, urea, phenol, diallyl phthalate, nylon, polyester, polycarbonate, polybutylene terephthalate, and polychlorotriate. Polymers such as fluoroethylene, polyacetal, methacrylic, acrylonitrile styrene, acrylonitrile butene styrene, polystyrene, polypropylene, vinyl chloride, vinylidene chloride, polyethylene, polytetrafluoroethylene, vinyl acetate, polybutadiene, polyurethane, silicone, etc. And molded and pulverized plastic products are preferred.

The mixing ratio of the ejected fluid liquid and soft solid particles is generally 1 in terms of the apparent volume ratio of solid particles/liquid due to cleaning power and pump performance.
In the range of 15o to 1/2, preferably 1/20 to 1/4
used in

Next, the injection processing conditions will be described.

The nozzle of the injection gun preferably has an inner diameter of 4 mm or more, preferably 8 to 16 mm, in order to allow a certain amount of fluid containing soft solid particles to pass through the nozzle necessary for cleaning.

The spray amount and pressure will vary depending on the type of object to be cleaned, the type of surface deposits, the degree of surface contamination, etc., but if the object to be cleaned is metal and to obtain the best cleaning effect, the jet amount should be 2 O with a nozzle with an inner diameter of 12φ.
A! /min or more, preferably 30 to 120 A/m
in, and the ejection pressure is 0.3 kg/cTn2G or more1
0 kg/cffl”G or less, preferably 0.5 to 6
kg/cm2G, and if it is less than 0.3 kvc+a''G, the collision force against the surface deposits is weak, and the amount of jetting per unit surface area of the object to be washed is insufficient, making it impossible to obtain a sufficient cleaning effect, and the jetting pressure IQ kg /cm2G or more, the collision force is too strong and the surface of the object to be washed is damaged.

In addition, the peak angle θ of the surface roughness and unevenness of the surface of the washed object is 90° or more, and most of them are obtuse angles of 120° or more. In order to contact the four parts, the spray angle α must be 3Q' or more, preferably 4
5° or more is good.

There is a contradictory relationship between the cleaning area of the object to be washed and the cleaning power, so it is practically appropriate for the nozzle spread angle to be within 120°, preferably within 9σ, and the spray distance between the nozzle and the object to be washed is It is within 1oOO11LtlL, preferably about 300 to 700 fights.

The cleaning time varies depending on the degree of adhesion of surface deposits, the amount of adhesion, the jetting pressure of the jetting fluid, the jetting amount, and the jetting angle, but considering work efficiency, it is usually 0.5 to 10 sec, preferably 1 sec.
~5 sec.

During cleaning work, if the object to be washed is shaken, the collision pressure of the ejected fluid will be eased and the cleaning power will be reduced. If a liquid pool is formed, the collision pressure of the ejected fluid will be relaxed and the cleaning power will be reduced. Therefore, it is necessary to tilt and fix the cleaning surface of the object to be washed so as not to form a liquid pool.

In addition, gas may be mixed in the ejected fluid, and when the gas is mixed in, a part of the surface of the soft solid particles will be covered with gas, and if that part directly collides with the surface deposits, the surface of the soft solid particles will be covered with gas. The impact force is increased compared to one completely covered with liquid, and the removal efficiency of surface deposits is increased. However, if the amount of gas mixed in is excessive, the gas becomes a driving source and the impact force is too strong, deforming or grinding the convex parts on the surface of the washed item, which is not appropriate, and the mixing ratio is determined by the volume ratio under jet pressure. So gas/jet fluid-1/
Used below 1.

The cleaning method of the present invention can completely clean the surface of the object that has undergone various surface treatments in a shorter time than conventional methods without causing damage such as deterioration or deformation, and can be used for continuous cleaning. It has the advantage of improving cleaning efficiency.

In particular, when cleaning with a jetted fluid containing soft solid particles made of plastic using a solvent as a liquid, it is effective in removing surface deposits containing oil and fat that are firmly attached to the surface of the object to be washed. Continuous cleaning has the advantage of being able to clean the object in a short time without changing the surface of the object.

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1 Puff scum adhering to a hairline buffed stainless steel sink was cleaned using the cleaning materials shown in Table 1. The washing conditions and results are shown in Table 1.

Table 1 Table 1 (continued) However, the particle size represents the mode diameter of the number-based distribution.

(The same applies to other Examples) However, evaluation judgments in all Examples and Comparative Examples are as follows.

O cleanliness ○...Completely cleaned.

△・・・It is completely cleaned, and when the exposure time is extended○
There is a possibility that it will become.

×...Cleanliness is insufficient.

0 surface change ○・−・−No difference from the perfect one can be recognized.

△...There is very slight matting, but it is almost perfect.

×...It is in a matte state.

Examples 2-7 The relationship between one type of solid particles of the cleaning material and cleaning is shown.

Using an object to be washed with the same image quality as in Example 1, cleaning was performed under the same conditions as in Example 1 except for the solid particles of the cleaning material, the cleaning reinforcement material (gas content), and the cleaning material injection pressure/injection amount. Ta. The results are shown in Table 2.

Ax-...Sin ■ Wl Niwa Ambiguous Cultivation Examples 8 to 11 The relation between the type of cleaning liquid (cleaning liquid) and the cleaning effect is shown.

Using an object to be washed with the same image quality as in Example 1, cleaning was carried out under the same conditions as in Example 1 except for the cleaning size liquid and the cleaning material injection pressure/injection amount. Add the results to Table 3.

Table 3 Comparative Examples 1 to 4 Comparison with Examples regarding each requirement of solid particles in cleaning is shown.

Using an object to be washed with the same image quality as in Example 1, cleaning was performed under the same conditions as in Example 1 except for the solid particles of the cleaning material. The results are shown in Table 4.

Examples 12-13 and Comparative Examples 5-6 The influence of the mixing ratio of cleaning materials on cleaning is shown.

Using an object to be washed with the same image quality as in Example 1, cleaning was performed under the same conditions as in Example 1 except for the mixing ratio of cleaning materials and the cleaning material injection pressure/injection amount. The results are shown in Table 5.

Table 5 *2 At the time of startup, the piping was clogged with solid particles.

Example 14 and Comparative Example 7 The influence of the cleaning enhancer (gas mixture) on cleaning is shown. Using an object to be washed with the same image quality as in Example 1, cleaning was performed under the same conditions as in Example 1 except for the cleaning reinforcement material and the cleaning material injection pressure/injection amount. The results are shown in Table 6.

Example 15 and Comparative Examples 8-9 The influence of the injection pressure and injection amount of cleaning material on cleaning is shown.

Using an object to be washed with the same image quality as in Example 1, cleaning was performed under the same conditions as in Example 1 except for the injection pressure/injection amount. The results are shown in Table 7.

Examples 16-17 The influence of the object to be washed and the image quality on cleaning is shown.

Items to be washed having the image quality shown in Table 5 were washed under the same conditions as in Example 1. The results are also shown in Table 8.

Table 8 Comparative Examples 10 and 11 Comparative examples of high-pressure jet cleaning using only liquid as the cleaning material are shown. 1,1.1-trichloroethane, which does not contain solid particles, was injected at high pressure as a cleaning agent using the same image quality as in Example 1, and the cleaning reinforcement material and cleaning agent injection pressure/injection amount were the same as in Example 1. Washing was performed under the same conditions as in 1. The results are shown in Table 9.

Table 9 Reference Examples Washing items and cleaning solution with the same image quality as Example 1 (i+1+1
−)! Ultrasonic cleaning was performed using J dichlorothane).

The washing conditions and results are shown in Table 10.

Table 10

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of the cleaning method of the present invention, and FIG. 2 is an explanatory diagram showing a cleaning process. 1... Nozzle/l/ 8... Ejection fluid 2.
・・Gushing fluid population 9・Object to be washed 3・°°Gas population 10・−・Polishing powder 4・Gun body 11・
-・Oil 5...Injection gun 12...Tank 6...Liquid 13...Solid coarse mixed drainage liquid 7・
... Soft solid particles 14 ... Circulation pump 15 - Surface deposits Applicant Asahi Kasei Corporation

Claims (1)

[Claims] l) A jetting fluid containing a liquid and soft solid particles is applied to the surface of the object to be washed at a low jetting pressure of 0.3 using the liquid as a driving source.
, a cleaning method characterized by removing surface deposits by spraying at 9/cm2G.