JPH0440271A - Drying method after degreasing and cleaning - Google Patents

Abstract

PURPOSE:To dispense with the replacement with fluorocarbon and to dry even a product generating a problem by heating within a short time without generating rust by degreasing and cleaning an object to be treated and drying the water bonded to the object to be treated in a sound field in which air is allowed to flow after cleaning. CONSTITUTION:An object to be treated is degreased and cleaned and, after cleaning, the water bonded to the object to be treated is dried in a sound field in which air is allowed to flow. That is, drying speed increases as the sound pressure in the sound field is raised but, in the drying of a product easy to generate rust, about 100 - 160dB is pref. As a result, the replacement with fluorocarbon or methylene chloride being in question presently is unnecessary and even a product generating a problem by heating can be dried within a short time without generating rust.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for drying adhering water after degreasing and cleaning of mechanical parts, tools, IC boards, etc.

[Conventional technology]

The following method is well known as a drying method in a cleaning method in which degreasing is performed using an alkaline aqueous solution or a surfactant-added aqueous solution, followed by water washing and drying.

(1) Dry by blowing air.

(2) Dry with hot air.

(3) Dry through a drying oven.

(4) After soaking in warm water, dry with hot air.

(5) After soaking in ethanol, dry with hot air. (Method aimed at improving hot air drying speed by replacing adhered water with ethanol, a low-boiling compound) (6) Immersing in a low-boiling compound such as fluorocarbons or methylene chloride, and drying with air at room temperature.

When drying after degreasing and cleaning, it is a problem if there is any adhesion during the 0th step.

■This is done for the purpose of preventing rust after degreasing and cleaning, but
From the viewpoint of rusting, productivity improvement, and economic efficiency, the problem is how to dry quickly and cheaply, and various efforts have been made to date as described above.

However, the conventional methods have the following problems, and it is desired to develop an effective drying method.

(1) Drying by blowing air takes a long time to dry and may cause rust.

(2) The method of drying with hot air can shorten the drying time and reduce the rust rate compared to (1) above, but it not only increases the energy cost and equipment cost for producing hot air, but also It cannot be applied to products whose performance is affected by heat application.

(3) The method of passing through a drying oven has the same problems as the method of drying with hot air described above.

(4) The method of immersing in hot water and then drying with hot air has a faster drying speed than the methods (1), (2), and (3) above, but the equipment cost is higher. Further, in the case of something like an IC board, there are problems similar to those described in (2) and (3) above.

(5) The method of immersing in ethanol and then drying with hot air has a faster drying speed than the method of immersing in hot water and drying with hot air, but requires additional equipment such as ethanol scattering prevention or recovery equipment. .

(6) The method of immersing in a low-boiling compound such as fluorocarbons or methylene chloride and drying it with air at room temperature has a high drying speed and is less affected by heat, but recently due to environmental concerns, technology that does not safely dissipate outside the system has been developed. It is difficult to establish and its use is likely to be regulated or prohibited.

[Means to solve the problem]

In order to eliminate such drawbacks, the present inventors conducted intensive experimental studies on a method for effectively drying adhered water, and came to propose the present invention. In the degreasing cleaning method that involves post-drying, after washing with water,
This is a drying method after degreasing and cleaning, which is characterized by drying adhering water in a sound field with air flowing through it.

That is, the object to be treated is degreased and cleaned using an alkaline aqueous solution or a surfactant-added aqueous solution, then washed with water, and the object to be treated with the washing water attached is moved into a sound field where the sound pressure is adjusted to a certain level or higher, and air is removed. This is a method of drying while flowing.

[For production]

It is generally known that the drying rate of water can be increased as the boundary film that governs mass and heat transfer is made smaller.

It is also known that drying speed can be increased by placing water-absorbed powder in a sound field and drying it while blowing air through it. This effect is said to be due to the vibration of the substance caused by sound pressure, which thins the barrier film for mass and heat transfer, and greatly increases the rate of diffusion of the substance and heat.

The present invention applies this effect to the drying of adhering water after degreasing and cleaning.

In the present invention, the higher the sound pressure in the sound field, the faster the drying speed becomes.
0dB is desirable.

〔Example〕

10mm x 100mm x 1mm thick mild steel plate with 5%N
After completely degreasing and cleaning with a degreasing process using a leaf aqueous solution,
Immediately after washing with water in the water washing process,
A sound field drying process in which air is flowed at a flow rate of 50 mm in diameter.
The sample was placed in a sound field forming container with a length of 200 mm, and the drying rate was measured under various conditions and the state of rust formation after drying was observed. The results are shown in the table below.

[Effect of Hathu]

There is no need to replace CFCs or methylene chloride, which are currently problematic, and even products that would cause problems when heated can be dried in a short period of time without rusting. The present invention has great industrial effects as it can solve such pollution problems.

Claims (1)

[Claims] 1. A degreasing and cleaning method in which an object to be treated is degreased, washed with water, and then dried, the drying method after degreasing and cleaning being characterized in that, after washing with water, adhering water is dried in a sound field in which air is flown.