JP6031743B2 - Dry cleaning device and dry cleaning method - Google Patents

Description

  The present invention relates to a dry cleaning apparatus and a dry cleaning method that perform cleaning by causing a laminar cleaning medium to fly in an internal space of a casing by a circulating air flow, and contacting a cleaning target (including the concept of collision).

A cleaning process is indispensable in the manufacture and recycling of products, and cleaning with a cleaning liquid such as a solvent or a surfactant is generally performed. However, a large amount of solvent or cleaning liquid is consumed, and the waste liquid is It has problems such as adverse environmental impact and heavy load on workers due to the use of chemicals.
On the other hand, there is also known a dry cleaning apparatus that performs cleaning by flying a flaky cleaning medium and colliding with an object to be cleaned without using a cleaning liquid (see Patent Documents 1 and 2).
Patent Document 3 discloses a cleaning device that supplies liquid in a spray form to a sponge ball as a flying body and collides with a portion to be cleaned such as a wall of a building, a window, or a side surface of a vehicle.

According to the method of adding moisture to a water-absorbing cleaning medium indirectly as in the technique described in Patent Document 3 or by directly humidifying the object to be cleaned, the affinity of the cleaning medium for the object to be cleaned is improved. And fine particles and oily dirt can be efficiently wiped off.
However, in some fields, it may not be desirable to wet the object to be cleaned with moisture. In general, a cleaning medium having water absorption is flexible with a fiber assembly or a sponge structure, and is not suitable for cleaning fixed substances such as flux.
In this regard, the techniques described in Patent Documents 1 and 2 use a flaky resin piece as a cleaning medium, and also provide a good result for cleaning a fixed object without wetting the object to be cleaned with moisture.
However, if the flying speed of the cleaning medium is increased in order to increase the cleaning ability, depending on the type of the object to be cleaned, the dirt on the object to be cleaned can be removed, but the powdered scrap of the resin cleaning medium itself caused by wear or collision However, there is a problem that the material adheres to the object to be cleaned and remains after the cleaning.
That is, it has been found that, although the initial purpose of removing dirt on the object to be cleaned can be achieved, a new problem arises that the cleaning surface becomes dirty again due to remaining scraped pieces of the cleaning medium itself.
The dirt after washing, which should be referred to as “resin residue”, is different from dirt such as flux to be washed, but it becomes a problem in the field of semiconductors and the like that do not like dirt and dust.
The present applicant has proposed a handy-type dry cleaning device that sucks external air by suction means to generate a negative pressure swirling airflow in the internal space of the housing, and causes a cleaning medium made of flaky resin pieces to fly. However, since the swirling airflow in such a relatively narrow space inevitably increases in speed, the above problem is remarkable.

  The present invention has been made in view of the situation as described above. In addition to being able to remove dirt on the original object to be cleaned, it is possible to prevent the scraped pieces of the cleaning medium itself from remaining after cleaning, The main object of the present invention is to provide a dry cleaning apparatus that can improve the quality of the surface and contribute to the expansion of the range of the object to be cleaned.

To achieve the above object, the present invention, the thin cleaning agent piece to fly by the air flow, a dry type cleaning apparatus for cleaning the cleaned object against the cleaning medium to the cleaning object, the cleaning medium A housing having an internal space for causing the air to fly, an opening provided in the housing for causing the cleaning medium to collide with the object to be cleaned while facing the object to be cleaned at the time of cleaning, and a circulating airflow in the internal space. In a dry cleaning apparatus having an airflow generating means for generating, mist generating means for generating mist composed of mist-like moisture particles is provided, and the mist wets the object to be cleaned when it collides with the object to be cleaned. a particle diameter enough to bounce off without a mist generated by the mist generating means is introduced into the internal space, is circulated as a gas-liquid mixed flow is mixed with the circulating air flow, the The strike in a state of being attached to the surface of the cleaning medium, the cleaning medium collides with the cleaning target object, it characterized that you wash the residue of the object to be cleaned and the cleaning medium.

The definitions of terms in this specification are as follows.
The “casing” in the present invention refers to a container-like structure provided with a space in a shape that is easy to generate a swirling air flow inside. The shape that easily generates the swirling airflow is a shape having a continuous inner wall in which the airflow flows and circulates along the inner wall of the housing, and more preferably a shape having a rotating body-shaped inner wall or an inner space. .
The “ventilation passage” is means for facilitating the flow of airflow in a certain direction, and is generally a tube shape having a smooth inner surface. However, for example, even if a plate-like flow path control plate having a smooth surface is used, a rectifying effect that facilitates the flow of gas in the direction along the surface is exhibited. And

In addition, the shape in which the airflow flows linearly is common, but the rectifying effect can be obtained even with a gentle curve that does not cause much flow path resistance. However, unless otherwise specified, the direction of the air passage means the direction of the air flow ejected at the air inlet.
In the present invention, an air passage that is a straight pipe shape, one end of which is connected to the air inlet of the inner wall of the housing and the other end is an air intake opening that is open to the atmosphere outside the housing. This is called “inlet”. The inlet generally has a low fluid resistance, has a smooth inner surface, and a circular, rectangular or slit shape is used for the cross section of the tube.

In the present invention, the “swirl airflow” means that the airflow accelerated by the inflow airflow from the air inlet flows while changing the direction along the inner wall of the housing, circulates back to the position of the air inlet, It is an airflow that merges with the incoming airflow. When the fluid forming the air flow is air, it is synonymous with “swirl air flow”. Generally, it is generated by flowing an air flow in a tangential direction of the inner wall in a closed space where the inner walls are continuous.
In the present invention, “moisture” refers to a concept including not only water but also a mixture of water and a liquid other than water.

According to the present invention, it is possible to highly accurately suppress a residue that is a powdered scrap generated by friction of the cleaning medium from remaining on the cleaning surface after cleaning, and to improve the quality of the cleaning surface, Since it can respond also to the field | area where a residue becomes a problem, it can contribute to the expansion of the range of a washing | cleaning target object.
In addition, the affinity of the cleaning medium for the object to be cleaned can be increased, and the cleaning ability can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a general | schematic side view which shows the use condition of the dry cleaning apparatus which concerns on the 1st Embodiment of this invention, (a) is a figure which shows the state in which mist has arisen by the mist production | generation means, (b) is mist in a housing | casing. It is a figure which shows the state currently attracted | sucked. It is the principal part horizontal sectional view and longitudinal cross-sectional view of the dry cleaning apparatus. It is a principal part horizontal sectional view and longitudinal cross-sectional view which show the modification of the arrangement position of the washing | cleaning medium discharge port. It is a principal part expanded sectional view which shows the airtight state of the opening part at the time of use of the dry cleaning apparatus. It is a photographic image based on the experimental result which shows the relationship between the washing | cleaning medium residue on a washing | cleaning target object, and the density | concentration of mist. It is a figure which shows the magnitude | size of a dry fog (trademark), The left side is a photograph image figure of a collection particle, The right side is a figure which shows the measurement result by the Franchoher diffraction method. It is a schematic diagram which shows the principle which does not wet a thing even if dry fog (trademark) hits a thing. It is a figure which shows the surface treatment method of the washing | cleaning medium in 2nd Embodiment. It is a figure which shows the wettability of the washing | cleaning medium before and after the surface treatment. It is a figure which shows the surface treatment method of the washing | cleaning medium in 3rd Embodiment. It is a photographic image which shows the comparison with and without a process in a film board. It is a graph which shows the hydrophilic property maintenance evaluation result according to a hydrophilization technique. It is a schematic sectional drawing which shows the basic composition of the dry cleaning apparatus of this invention. It is a figure which shows the washing | cleaning operation | movement of the apparatus. It is a perspective view which shows the use condition of the dry cleaning apparatus.

Embodiments of the present invention will be described below with reference to the drawings.
First, the basic configuration and function of the dry cleaning apparatus of the present invention will be described with reference to FIGS.
Based on FIG. 13, an outline of the configuration of the handy-type dry cleaning device 2 according to the present invention will be described. FIG. 13A is a transverse sectional view taken along line AA, and FIG. 13B is a longitudinal sectional view taken along line BB.
The dry cleaning device 2 includes a dry cleaning housing (hereinafter simply referred to as “housing”) 4 having a flying space for the cleaning medium 5 therein, and an intake means 6 for reducing the pressure inside the housing 4. .
The casing 4 is configured integrally with a cylindrical upper casing 4A as a casing main body and an inverted conical lower casing 4B. Here, the upper part and the lower part are convenient names on the drawing, and are not necessarily related to the upper and lower sides on the actual machine.

The lower housing 4B is integrally provided with an intake port 8 at the top of the cone, and functions as a suction duct.
The suction means 6 has a flexible suction hose 10 connected at one end to the suction port 8 and a suction device 12 connected to the other end of the suction hose 10. As the suction device 12, a household vacuum cleaner, a vacuum motor, a vacuum pump, or a device that indirectly generates a low pressure or a negative pressure by pumping fluid can be used as appropriate. Note that the positional relationship between the upper and lower surfaces of the member is merely a reference on the drawing.

The bottom surface of the upper housing 4A is a fitting recess 4A-1 that joins the upper end of the lower housing 4B, and the upper housing 4A and the lower housing 4B are separable. The upper surface 4A-2 of the upper housing 4A is sealed.
A porous separation plate 14 is provided as a porous means at the boundary between the bottom surface of the upper housing 4A and the lower housing 4B. The separation plate 14 is a plate-like member having holes such as punching metal. The separation plate 14 prevents the cleaning medium 5 from moving toward the lower housing 4B when sucked. In FIG. 13A, the display of the separation plate 14 is partially omitted. The size of the cleaning medium 5 is exaggerated for easy understanding.
The porous means may be a porous shape having many pores of a size that allows air and dust (removed material removed from the object to be cleaned) to pass through without passing through the cleaning medium 5, such as a slit plate or a net. As long as the material has a smooth surface, resin or metal may be freely selected.
The porous means is arranged as a plane orthogonal to the central axis of the swirling air flow. By being orthogonal to the central axis of the swirling airflow, the airflow flows in the direction along the porous means, thereby preventing the cleaning medium 5 from staying.
In order to suppress the attenuation of the swirling air flow, it is desirable that the inner surface of the housing is smooth without steps and irregularities.

The porous means can be re-flighted by the cleaning medium adsorbed on the surface by being arranged on the surface along the swirling air flow.
The material of the housing 4 is not particularly limited, but is preferably made of metal such as aluminum or stainless steel in order to prevent wear due to adhesion of foreign matter or friction with the cleaning medium, but a resinous material may be used. it can.

A cylindrical channel restricting member 16 is provided as a part of the casing at the center of the upper casing 4A so that the cylindrical axis of the upper casing 4A is a common axis. The lower end is fixed to the separation plate 14.
The flow path restriction member 16 is provided for the purpose of improving the flow velocity by reducing the cross-sectional area of the swirling air flow. A ring-shaped swirling air flow moving space (cleaning medium flying space) having a smooth wall surface is formed in the upper housing 4A by the flow path restricting member 16.
Depending on the shape of the upper casing 4A, the central axis of the flow path restricting member 16 and the central axis of the upper casing 4A do not necessarily have to be common, and may be eccentric if a ring-shaped space can be secured. good.

An opening 18 is formed in a part of the side surface of the upper housing 4 </ b> A so that the cleaning medium 5 flying in the swirling air flow contacts or collides with the object to be cleaned.
The upper housing 4A has a cylindrical shape whose height is extremely small with respect to the diameter. By providing the opening 18 in a part of the side surface forming the height, the housing 4 as a whole is shown in FIG. As shown in FIG. 4, the outer peripheral portion other than the opening 18 largely escapes (separates) from the cleaning target 20, and the degree of freedom of local contact with the cleaning target 20, in other words, pinpoint cleaning is enhanced. .
The opening 18 has a shape obtained by cutting the side surface of the upper housing 4A by a flat cross section parallel to the cylindrical axis, and has a rectangular shape when viewed from a direction orthogonal to the cylindrical axis.

An air inlet 22 is formed on a side surface of the upper housing 4A, and an inlet 24 as a swirling air flow generating means and an air passage is connected to the air inlet 22 from the outside of the upper housing 4A. It is integrally fixed to the upper housing 4A.
The inlet 24 is set substantially parallel to the separation plate 14, and the ventilation direction thereof is inclined with respect to the radial direction of the upper housing 4 </ b> A, and the extension line at the center of the ventilation path is positioned so as to reach the opening 18. Yes.
The inlet 24 has a width extending in the height direction of the upper housing 4A. One inlet 24 having a diameter or width smaller than the height of the upper housing 4A may be arranged, or a plurality of single inlets may be arranged in the height direction.
As shown in FIG. 13, when the opening 18 contacts and closes the object 20 to be cleaned, the inside of the housing 4 becomes a closed space, and outside air flows from the inlet 24 at a high speed. 5 is accelerated toward the opening 18 and a swirling airflow 30 as a swirling airflow is generated.
The swirling air flow generated when the closed space is formed has an effect of blowing away the cleaning medium adsorbed on the separation plate 14 and re-flighting.

When the opening 18 is opened, the opening 18 has an area large enough to set the internal pressure at the air inlet 22 to atmospheric pressure or the vicinity thereof. Further, the air inlet 22 is also arranged at a position where the atmospheric pressure or the vicinity thereof tends to be reached when the opening 18 is opened.
By providing such a configuration, while the dry cleaning device 2 is not applied to the object to be cleaned, the air inlet 22 approaches the atmospheric pressure, so that the differential pressure with the outside decreases, and the airflow that flows in as a result. Is dramatically reduced. On the other hand, since the airflow flowing in from the opening 18 increases, the cleaning medium 5 can be prevented from leaking out of the housing 4.
In addition, when the opening 18 is opened, the total amount of airflow flowing in is 2 to 3 times as compared with when the opening 18 is closed, so that the lamellar cleaning medium is adsorbed on the porous means. , Do not leak out of the case without flying again. This is called a cleaning medium adsorption effect when the opening is opened.

The cleaning medium 5 is a set of cleaning pieces made of flaky resin film pieces, but is also used here as a single piece of flaky cleaning piece.
The flaky cleaning medium is a thin piece having an area of 1 mm ² or more and 200 mm ² or less. The cleaning medium is made of a durable material such as acrylic (PMMA), polycarbonate (PC), polyethylene terephthalate (PET), cellulose triacetate (TAC), polyimide (PI) or polystyrene (PS). The film has a thickness of 0.02 mm to 1.0 mm.
However, depending on the object to be cleaned (hereinafter also referred to as “cleaning object”), it may be effective to change the thickness, size and material of the cleaning medium, and the use of these cleaning media is within the scope of the present invention. Therefore, it is assumed that the cleaning medium conditions are not affected.
Regarding the material of the cleaning medium, not only the resin but also minerals such as mica, ceramics, glass, and metal foil can be used by making them thin, light and easy to fly.

The ring-shaped internal space 26 of the upper housing 4 </ b> A is a space that has a function of causing the cleaning medium 5 to fly by the swirling air flow so as to come into contact with the cleaning target 20 facing the opening 18.
The internal space 34 of the flow path restriction member 16 is a space where the swirling air flow does not act.

A cleaning operation (hereinafter referred to as a cleaning operation) by the dry cleaning apparatus 2 configured as described above will be described with reference to FIG. In FIG. 14, the thickness of the member is omitted, and the internal space 34 as a static space is hatched for easy understanding.
14B shows a state in which the opening 18 is separated from the object 20 to be cleaned and the opening 18 is opened to perform intake, and FIG. 14A shows the state where the opening 18 is applied to the object 20 to be cleaned. Indicates a blocked state.
Prior to the cleaning operation, the cleaning medium 5 is supplied into the housing 4. The cleaning medium 5 supplied into the housing 4 is sucked by the separation plate 14 and held in the housing 4 as shown in the lower diagram of FIG.
Since the inside of the housing 4 is in a negative pressure state due to intake air, air outside the housing flows into the housing 4 through the inlet 24, but the flow in the inlet 24 at this time is small in both flow velocity and flow rate. The swirling air flow 30 generated in the housing 4 does not reach the strength for causing the cleaning medium 5 to fly.

When the cleaning medium 5 is supplied and held in the housing 4, as shown in FIG. 14A, the opening 18 is put in a closed state by hitting the surface of the cleaning target 20 to be cleaned.
When the opening 18 is closed, intake from the opening 18 stops, so the negative pressure in the housing 4 increases at a stretch, and the amount of air sucked through the inlet 24 and the flow velocity increase and are rectified in the inlet 24. A high-speed air flow is blown out into the housing 4 from the inlet outlet (air inlet 22).
The blown air flow causes the cleaning medium 5 held on the separation plate 14 to fly toward the surface of the cleaning object 20 facing the opening 18.
The air flow becomes a swirling air flow 30 and flows in an annular shape along the inner wall of the housing 4, and a part of the air flow is sucked by the suction means 6 through the hole of the separation plate 14.
Thus, when the swirling air flow 30 that has flown in the annular shape inside the housing 4 returns to the outlet portion of the inlet 24, the air flow entering from the inlet 24 is accelerated while joining the swirling air flow 30. In this way, a stable swirling air flow 30 is formed in the housing 4.

The cleaning medium 5 swirls within the housing 4 by this swirling air flow and repeatedly collides with the surface of the cleaning object 20. Due to the impact caused by the collision, the dirt is separated from the surface of the cleaning object 20 in the form of fine particles or powder.
The separated dirt is discharged to the outside of the housing 4 by the suction means 6 through the hole of the separation plate 14.
The swirling air flow 30 formed in the housing 4 has a swirling axis orthogonal to the surface of the separation plate 14, and the swirling air flow 30 becomes an air flow parallel to the surface of the separation plate 14.
Therefore, the swirling air flow 30 is sprayed from the lateral direction onto the cleaning medium 5 sucked on the surface of the separation plate and enters between the cleaning medium 5 and the separation plate 14, and the cleaning medium 5 sucked on the separation plate 14. Is peeled off from the separation plate 14 and re-flys.
Further, since the opening 18 is blocked and the negative pressure in the upper housing 4A increases and becomes close to the negative pressure in the lower housing 4B, the force for sucking the cleaning medium 5 against the surface of the separation plate 14 is also reduced. As a result, the cleaning medium 5 can fly more easily.
Since the swirling air flow 30 is accelerated in a certain direction, a high-speed air flow is easily generated, and a high-speed flight movement of the cleaning medium 5 is also facilitated. The cleaning medium 5 that swivels at high speed is difficult to be sucked by the separation plate 14, and the dirt attached to the cleaning medium 5 is easily separated from the cleaning medium 5 by centrifugal force.

FIG. 15 shows a practical example of cleaning by the dry cleaning device 2 described above.
The object to be cleaned is a dip pallet used in the above-described flow solder bath process, and is denoted by reference numeral 100.
In the dip pallet 100, mask openings 101, 102, 103 are opened, and the flux FL is deposited and solidified around the holes of the mask openings. This accumulated and solidified flux FL is dirt to be removed.
As shown in FIG. 15, the base part (inlet 8 part) of the lower casing 4 </ b> B is grasped with the hand HD, and the opening 18 of the casing 4 is pressed against the part to be cleaned in the intake state.
Before the opening 18 is pressed against the part to be cleaned, the inside of the housing 4 is sucked and the cleaning medium 5 is sucked by the separation plate 14, so that the opening 18 faces downward, but the housing The cleaning medium 5 does not leak from the inside to the outside.
Of course, after the opening 18 is pressed against the site to be cleaned, the inside of the housing becomes airtight, and the cleaning medium does not leak out.

When the opening 18 is pressed against the portion to be cleaned, the inflow airflow by the inlet 24 increases rapidly, a strong swirling airflow 30 is generated in the housing 4, and the cleaning medium 5 sucked by the separation plate 14 is caused to fly, The flux FL is removed by colliding with the flux FL adhered and solidified on the site to be cleaned of the dip pallet 100.
As described above, the cleaning operator can hold the base of the lower housing 4B in the hand HD, move it with respect to the dip pallet 100, sequentially move the portion to be cleaned, and remove all the adhered and solidified flux FL. it can.
In the state of FIG. 15, the peripheral portion of the mask opening 101 of the dip pallet 100 is cleaned, and the peripheral portions of the mask openings 102 and 103 are in the process of cleaning.
Even if the opening 18 is moved away from the portion to be cleaned when the opening is moved with respect to the portion to be cleaned, the cleaning medium 5 does not leak out of the housing due to the above-described cleaning medium adsorption effect, so the number of cleaning media is maintained. In addition, the cleaning performance is not deteriorated due to the decrease in the amount of the cleaning medium.

Since the cleaning medium 5 is gradually destroyed by the impact caused by the collision with the cleaning site during repeated use, and is collected by the suction device 12 together with the flux (dirt) removed from the dip pallet 100 at the cleaning site, the dry cleaning device When the is used for a long time, the amount of the cleaning medium held in the housing is reduced.
In such a case, a new cleaning medium group is supplied into the housing 4.

Based on FIG. 1 thru | or FIG. 7, 1st Embodiment about the characteristic part (not shown in FIG. 13 thru | or FIG. 15) of this invention is described. In addition, the same part as the said basic structure is shown with the same code | symbol, and only a principal part is demonstrated (it is the same in the following other embodiment).
As shown in FIG. 1, the dry cleaning apparatus 50 according to the present embodiment includes a mist generating unit 52 that is a separate body from the casing 4 as the apparatus main body. In the present embodiment, an ultrasonic humidifier KNC type “Kiritaro” (manufactured by Wetmaster) was used as the mist generating means 52.
The mist generating means 52 may be integrated with the housing 4. In this case, you may connect by the flow path which guides the mist generated from the mist production | generation means in a housing | casing.
When the mist generating means 52 is provided separately from the housing 4, the dry cleaning device 50 can also be referred to as a “dry cleaning system”.
When the switch of the mist generating means 52 connected to a power source (not shown) is turned on, as shown in FIG. 1A, the mist M is ejected from the mist ejection port 52a and spreads in a cloud shape.
When the opening 18 of the housing 4 is blocked by the cleaning object 20, external air flows from the inlet 24 into the housing at a high speed, the swirling air flow 30 is generated by the above mechanism, and the cleaning medium 5 flies. And collide with the object 20 to be cleaned.
When the mist generating means 52 is arranged in the vicinity of the casing, as shown in FIG. 1 (b), the mist M spreading in a cloud shape has a negative pressure at which external air flows from the inlet 24 into the casing at high speed. The air is sucked into the inlet 24 by the action and mixed with the swirling air flow 30 in the housing, and the swirling air flow 30 swirls as a gas-liquid mixed flow.
While the mist M is being supplied, the swirling air flow 30 is a gas-liquid mixed flow.

The diffused mist M adheres to the cleaning medium 5, wets the cleaning medium 5, or comes into contact with the object 20 to be cleaned.
As a result of the experiment, it was confirmed that it is possible to suppress the generation of a residue that is a powdery piece of the cleaning medium 5 on the cleaning surface of the cleaning target object 20 after cleaning.
The mechanism of residue control is not clear, but can be estimated as follows.
When moisture particles constituting the mist adhere to the surface of the cleaning medium 5 and collide with the object 20 to be cleaned in this state, the water particles are interposed between the cleaning medium and the object to be cleaned (including dirt) and both members. The frictional shock is eased, and the cleaning medium is prevented from being scraped.
Further, brittle fracture of the microscopic cleaning medium due to frictional heat at the time of collision is suppressed by the cooling effect of the water particles.
In addition, it was confirmed that the dirt removal performance, which is the original purpose, is improved simultaneously with the residue control. This is because moisture particles adhere to the surface of the cleaning medium, thereby increasing the affinity of the cleaning medium for the dirt of the object to be cleaned, and improving the chemical or physical adsorption force against the dirt.
Further, it was confirmed that the temperature of the object to be cleaned was lowered by the contact action of the gas-liquid mixed flow.

Generally, when cleaning is performed by causing the cleaning medium to collide with the object to be cleaned, when the flying cleaning medium collides with the object to be cleaned at the opening, or when the cleaning media collide with each other in the internal space of the casing, Phenomenon in which the cleaning medium, the object to be cleaned, and the internal space rise in temperature due to frictional heating, or the cleaning medium sticks due to the generated static electricity or a residue is generated on the object to be cleaned when it collides with the wall surface of the internal space It was observed.
The swirling gas-liquid mixed flow generated by sucking air and mist can reduce frictional heat generation and also has a static elimination effect, which eliminates the sticking of the cleaning medium, improves the cleaning performance, and removes residue on the object to be cleaned. It can be extinguished.

“Mist” in the present invention refers to water particles called dry fog (registered trademark) and dry mist (registered trademark), and water particles having a particle size of 100 μm or less, preferably FIG. (Extracted from the homepage), the maximum particle size is about 50 μm and the average particle size is about 10 μm.
The mist having such a particle size has a property that when the mist collides with the object to be cleaned, the mist rebounds without wetting the object to be cleaned.
As shown in FIG. 7 (b), when a large soap bubble hits an object, it ruptures and wets the surface of the object. However, as shown in FIG. 7 (a), a small soap bubble is repelled and wetted when it hits the object. No (excerpt from Ikeuchi's website).
In the case of the mist used in the present invention defined above, the same behavior as in FIG. 7A is exhibited and the object to be cleaned is not wetted.
The cleaning medium flies after removing the dirt, and the newly supplied cleaning medium with mist again collides with the object to be cleaned, so that the dirt can be continuously removed.

It was found that the residue of the cleaning medium depends on the concentration of mist in the swirling gas-liquid mixed flow. When the mist concentration is sufficiently high, no residue is generated (see FIG. 5A), but when the concentration is lowered, a residue is generated on the entire surface of the cleaning target (see FIG. 5C).
Table 1 shows the water absorption rate of the resin material.
PI, TAC, PC, etc., which have a large water absorption rate, can easily retain the cleaning liquid (mist) on the surface, increase the affinity for dirt, and improve the chemical or physical adsorption power against dirt, thereby Not only the removal performance is improved, but also the reduction of residue is remarkable.

Experiments have shown that the setting of an appropriate ratio and particle size of mist in the swirling air flow 30 is effective in reducing residue residue.
For this purpose, it is desirable to modify the surface of the resin cleaning medium so that the mist having the appropriate particle diameter can be adsorbed on the surface. A specific method for this point will be described in another embodiment.

When the cleaning medium becomes dirty due to repeated use, as shown in FIG. 2, the openable and closable cleaning medium discharge port 58 provided in a part of the separation plate 14 is opened by a handle mechanism (not shown) and remains in the casing. Collect the used cleaning medium into the suction device.
The cleaning medium discharge port 58 is closed during a normal cleaning operation. As shown in FIG. 3, the cleaning medium discharge port 58 may be provided on a part of the side surface of the flow path restriction member 16 that is a cylindrical member. The flow path restriction member 16 in this example has a hollow cylindrical shape. Further, as in this example, the upper housing 4A can be configured to have an inverted conical shape with respect to the lower housing 4B.
The cleaning medium discharge port 58 may be provided so as to slide in the circumferential direction, or may be provided so as to be openable and closable outward in the radial direction with a hinge configuration (not shown) as indicated by a two-dot chain line.
To supply a new cleaning medium, the opening 18 is brought close to a new cleaning medium group in a state where the suction device is operated, and the housing is replenished by suction. In this apparatus, since the cleaning medium separating means 14 can suck only an amount of the cleaning medium that can be adsorbed, an appropriate amount of the cleaning medium can be easily supplied.
When using a cleaning medium that is easily clogged, a fine convex portion may be formed on the cleaning medium separating means 14 so that the cleaning medium can easily fly.

As shown in FIG. 4, it is more effective to arrange a flexible member 60 such as a rubber packing around the opening 18 in order to improve the adhesion to the cleaning object.
In FIG. 4, reference numeral 62 indicates dirt on the cleaning object 20, and 64 indicates a rubber sheet on which the cleaning object 20 is placed. Even if the object to be cleaned has a shape with irregularities and openings, it is possible to increase the negative pressure in the housing by closing the openings with a flexible rubber sheet or the like, and the cleaning medium can be cleaned without leaking.
The mist generating means 52 only needs to be able to generate a mist that satisfies the above particle diameter conditions. For example, a mist twister R (manufactured by Spraying Systems Co.) or an ultrasonic humidifier TUH-A10-W (manufactured by Toyotomi) ) Etc. can be employed.

A second embodiment will be described based on FIGS. 8 and 9.
As described above, if the surface of the resin cleaning medium is modified so that mist having an appropriate particle size can be adsorbed on the surface, further improvement of the cleaning function and the residue suppressing function can be expected.
The purpose of this embodiment is to chemically modify the surface of the cleaning medium. The apparatus configuration is the same as in the above embodiment.
For the cleaning medium 5 used in the above embodiment, as shown in FIG. 8 (Three Bond Technical News; extracted from March 20, 1987), an oxygen absorption (ozone generation) wavelength of 185 nm, ozone UV / O _{3 is} treated with a low-pressure mercury lamp that emits ultraviolet light with a wavelength of 254 nm, which is a decomposition (oxygen free radical generation) line.
Specifically, it is desirable to process 10 J / cm ² or more with a low-pressure mercury lamp with an output of 50 mW / cm ² . As a result, the cleaning medium changes from water repellent to hydrophilic.
UV / O ₃ treatment clearly improves the wettability of the cleaning medium (see FIG. 9 (Three Bond Technical News; excerpted from March 20, 1987)). The cleaning medium treated with UV / O ₃ makes it easy to keep the supplied mist on the surface, dramatically improves the affinity for dirt, and only improves the chemical or physical adsorption power to dirt. In addition, the reduction of the residue was remarkable.
The experimental results are shown in Table 2.

A third embodiment will be described with reference to FIGS.
The purpose of this embodiment is to physically modify the surface of the cleaning medium. The apparatus configuration is the same as in the above embodiment.
For the cleaning medium 5 used in the above embodiment, as shown in FIG. 10, a nanostructure is transferred from the mold to the surface of the cleaning medium using a mold having a nanostructure formed thereon. As a result, a nanostructured cleaning medium (replica) is formed.
Specifically, the photoresist on the substrate is patterned by light or electron beam lithography. The pattern shape is a dot pattern having a depth of 100 nm, a pitch of 400 nm, and a width of 400 nm. An etching pattern is formed on the substrate by reactive ion etching (RIE) using the photoresist pattern as a mask. After metallizing the etching patterning surface of the substrate by vapor deposition, electroless plating, sputtering, etc., nickel plating is performed in a sulfamic acid electroforming bath, thereby producing a mold having a nanostructure on the surface.
By the nanoimprint method, the mold is heated to 150 ° C., and the acrylic film is pressed at 1 MPa for about 1 minute, whereby the cleaning medium having the nanostructure on the surface is transferred and molded.

FIG. 11 shows the appearance of the surface when water is sprayed on the film provided with the nanostructure and the untreated film flat plate. A film with nanostructures on the surface clearly shows water wetting on the surface, and a film surface without nanostructures on the surface clearly shows water repellency.
Moreover, the hydrophilic maintenance evaluation result according to the hydrophilization technique is shown in FIG. The nanostructured cleaning medium provided a wet area more than 3 times that of the untreated flat plate.
The cleaning medium with nanostructures formed on the surface has a larger actual surface area than the apparent surface area due to the mist generated by the mist generation means getting wet with the uneven structure on the surface of the cleaning medium. The hydrophilicity will be improved by reducing.
As a result, it is easy to hold the mist on the surface, the affinity for dirt is increased, and the chemical or physical adsorption force against flux dirt remaining after soldering, which is the object to be cleaned, is improved. Not only is the removal performance improved dramatically, but the reduction in residue is significant (see Table 2).

  By applying the above-mentioned chemical or physical hydrophilic treatment to the surface of the cleaning medium, a hydrophilic coat or the like is not necessary, so the production process of the hydrophilic member can be omitted, and the cost of the hydrophilic base material can be further reduced. Can contribute to high functionality. Moreover, hydrophilic maintenance property can be improved rather than the conventional hydrophilization technique.

In each of the above embodiments, application to a portable dry cleaning device that generates a swirling air flow by air suction is illustrated, but the present invention is not limited to this.
That is, even in the permanent type in which the casing (cleaning tank) is fixed in position and the object to be cleaned is moved, the problem of cleaning medium residue similarly occurs when the speed of the circulating airflow is high.
Even in the permanent type, the residue problem can be solved by flying the cleaning medium by the gas-liquid mixed flow mixed with mist.

DESCRIPTION OF SYMBOLS 5 Cleaning medium 6 Intake means as an airflow generation means 8 Intake port 14 Separation plate as a porous means 18 Opening part 20 Object to be cleaned 24 Inlet as a ventilation path 52 Mist generation means

JP 2007-029945 A JP 2009-226394 A Utility Model Registration No. 2515833

Claims (9)

A dry cleaning device that causes a laminar cleaning medium to fly by an air current and applies the cleaning medium to an object to be cleaned to clean the object to be cleaned,
A housing having an internal space for allowing the cleaning medium to fly; an opening provided in the housing for causing the cleaning medium to collide with the cleaning object while facing the cleaning object during cleaning; and the internal space. In a dry cleaning apparatus having an airflow generating means for generating a circulating airflow,
Comprising mist generating means for generating mist composed of mist-like moisture particles;
The mist has a particle size that is such that it rebounds without getting wet when the object to be cleaned collides with the object to be cleaned.
The mist generated by the mist generating means is introduced into the internal space, mixed with the circulating airflow, circulated as a gas-liquid mixed flow, and the cleaning medium is attached to the surface of the cleaning medium. A dry cleaning apparatus, wherein the cleaning object is made to collide with the object to be cleaned and the residue of the object to be cleaned and the cleaning medium are cleaned. The dry cleaning apparatus according to claim 1,
The casing draws air introduced from the outside into the internal space through the air passage, and a swirling airflow as the circulating airflow in the internal space by sucking the air introduced into the internal space through the air passage. An air inlet to be generated, and a porous means for passing the removed material removed from the object to be cleaned to the air inlet side without passing through the cleaning medium,
The dry cleaning apparatus according to claim 1, wherein the air flow generating means is suction means connected to the intake port. The dry cleaning apparatus according to claim 2, wherein
The dry cleaning apparatus, wherein the mist is introduced from the air passage. In the dry-type cleaning apparatus as described in any one of Claims 1-3,
The dry cleaning apparatus, wherein the cleaning medium is composed of a flaky resin film piece. In the dry-type cleaning apparatus as described in any one of Claims 1-3,
The dry cleaning apparatus according to claim 1, wherein a particle diameter of the mist is 100 μm or less. The dry cleaning apparatus according to claim 5, wherein
The dry cleaning apparatus according to claim 1, wherein the mist has a maximum particle size of about 50 μm and an average particle size of about 10 μm. In the dry-type cleaning apparatus as described in any one of Claims 1-6,
A dry cleaning apparatus, wherein a surface of the cleaning medium has hydrophilicity . The dry cleaning apparatus according to claim 7,
A dry cleaning apparatus, wherein the surface of the cleaning medium has a nanostructure . A circulating airflow is generated in the internal space of the housing by the airflow generating means, and the cleaning medium is caused to fly by the circulating airflow, and the cleaning medium is passed through an opening provided in the housing and facing the object to be cleaned. In the dry cleaning method in which the object to be cleaned is washed against the object to be cleaned,
A mist composed of mist-like moisture particles generated by the mist generating means, and having a particle diameter that is rebounded without getting wet when the object to be cleaned collides with the object to be cleaned is introduced into the internal space. In the state where the mist is mixed with the circulating airflow and circulated as a gas-liquid mixed flow, and the mist is adhered to the surface of the cleaning medium, the cleaning medium is collided with the cleaning object, and the cleaning object and the cleaning medium A dry cleaning method characterized in that the residue is washed .

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