JPH0259086A - Washing method and apparatus - Google Patents

Abstract

PURPOSE:To efficiently wash an object to be washed by a method wherein a washing solution is ejected in a washing solution bath to wash the object to be washed and subsequently taking out the object to be washed from said bath to eject a low b.p. org. solvent thereto. CONSTITUTION:The object 54 to be washed held to a holding bucket 50 is moved within the washing solution bath 100 positioned at the lower part in a washing tank 2 by a moving means 52 and a washing solution containing a low b.p. org. solvent and a high b.p. org. solvent is ejected in said washing solution bath 100 by a jet means 14 and the washing solution bath 100 is heated by a heating means 24 to wash the object 54 to be washed. This washed object 50 to be washed is raised to the finish region 10 positioned at the upper part in the washing tank 2 and the low b.p. org. solvent in a sump 102 is ejected to the object to be washed in the finish region by a finish jet means 30 to finish the object to be washed.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a cleaning method and apparatus particularly suitable for automatic cleaning of articles to which paint such as printing ink or paint has adhered.

<Prior Art and Problems> Generally, in a gravure printing machine used for multicolor printing, various members such as an ink tray, an ink vibrator, and an applicator are detachably attached. In multi-color printing using such a gravure printing machine, printing for each color is repeated the required number of times, but when changing the printing color, various members to which the printing ink used in the previous printing has adhered are It is necessary to remove and clean it. Therefore, as a cleaning method for the above-mentioned parts in the Mark 1111 machine,
(a) Simply immerse the parts to be cleaned in a bath of cleaning liquid such as an organic solvent? A U-immersion method and (b) a spray method in which a cleaning liquid is sprayed onto the member to be cleaned have been proposed and put into practical use.

However, the above-mentioned simple immersion method has poor cleaning efficiency and requires immersion to be carried out for a very long time, and even if it does so, it is not always possible to clean the product sufficiently well.

On the other hand, in the spray method described above, even if the cleaning liquid is sprayed from various directions, especially if the part to be cleaned has a complicated shape, some parts may remain where the cleaning liquid cannot directly impinge, resulting in incomplete cleaning. turn into. For this reason, in the printing industry, manual cleaning using a cleaning brush cannot be avoided in addition to or in place of the simple cleaning method or spray method described above. Ta. In addition to being cumbersome, manual cleaning operations also pose hygiene problems due to the organic solvents used as the cleaning liquid.

<Problem of the Invention> In order to solve the above-mentioned problems in the prior art, the present inventors previously disclosed in the specification and drawings of Patent Application No. 216498 of 1988 that a member to be cleaned, that is, an object to be cleaned, is placed in a cleaning liquid bath. We have proposed a unique cleaning method in which the object to be cleaned is moved in a cleaning liquid bath and the cleaning liquid is sprayed into the cleaning liquid bath in addition to immersion in the cleaning liquid bath, and a cleaning apparatus convenient for carrying out such a cleaning method.

According to the cleaning method and cleaning apparatus previously proposed by the present inventors, objects to be cleaned can be cleaned significantly better than conventional simple dipping methods and spraying methods. However, such cleaning methods and cleaning AA settings are still not fully satisfactory, and according to the experience of the present inventors, it may not be possible to obtain sufficiently good results depending on the type of printing ink, etc. Ta.

Therefore, the main technical problem of the present invention is to further improve the above-mentioned cleaning method and cleaning apparatus proposed by the present inventors so that superior cleaning efficiency can be achieved. be.

<Means for Solving the Invention> As a result of further extensive research and experiments, the present inventors have determined that in the cleaning process, the cleaning liquid bath in which the object to be cleaned is immersed contains a low boiling point Ia solvent and a high boiling point organic solvent. At the same time, an improvement is added in which the cleaning liquid bath is heated, and furthermore, after the cleaning process, a finishing process is performed in which the object to be cleaned is taken out from the cleaning liquid bath and a low boiling point organic solvent is injected onto the object to be cleaned. For example, we have found that the above technical problem can be achieved.

That is, according to the present invention, a low boiling point solvent and a high boiling point solvent are used.
immersing the object to be cleaned in a cleaning liquid bath containing an e-agent; heating the cleaning liquid bath; moving the object to be cleaned in the cleaning liquid bath; and immersing the object in the cleaning liquid bath. a cleaning step comprising injecting a cleaning liquid into the cleaning liquid bath; and a finishing step comprising removing the object to be cleaned from the cleaning liquid bath after the cleaning step and injecting a low boiling point organic solvent onto the object. A cleaning method is provided comprising the following steps.

Further, according to the present invention, a cleaning device suitable for carrying out the above-mentioned cleaning method includes a cleaning tank having a cleaning liquid located at the bottom and a finishing area located above the cleaning liquid, and a cleaning tank disposed in the cleaning tank. a packet for holding an object to be cleaned; a packet lifting means for raising and lowering the packet; a cleaning injection means for spraying a cleaning liquid containing a low boiling point organic solvent and a high boiling point organic solvent onto the cleaning liquid; A cleaning device is provided, comprising a finishing injection means for injecting a solvent into the finishing area, and a heating means disposed in the cleaning area.

<Preferred Specific Examples of the Invention> Hereinafter, preferred specific examples of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 schematically illustrates a preferred embodiment of a cleaning device constructed in accordance with the present invention. The illustrated cleaning device includes a cleaning tank designated as a whole by number 2. This cleaning tank 2 is
It includes a tank main body 4 having a substantially rectangular parallelepiped shape and an opening/closing member 17ij6 disposed on the open upper surface of the tank main body 4. The rear edge (right end in FIG. 1) of the door 6 is rotatably attached to the tank body 4, and can be pivoted open and closed between a closed position shown by a solid line and an open position shown by a two-dot chain line. The tank body 4 defines a cleaning area 8 located at the bottom, a finishing area 10 located above the cleaning area 8, and a drying area 12 located further above the finishing area 10.

A cleaning spray means 14 is provided in association with the cleaning area 8 of the cleaning tank 2. The cleaning injection means 14 includes a plurality of injection nozzles 16 and a pump 18. The plurality of injection nozzles 16 are arranged on the lower side wall of the tank body 4 at appropriate intervals in the horizontal and vertical directions. pump 18
Its inlet side is connected to the cleaning zone 8 by a line 20, and its outlet side is connected to the injection nozzle 16 by a line 22. At the bottom of the cleaning area 8, heating means 24 are arranged. Furthermore, a waste liquid line 25 having an on-off control valve (not shown) is connected to the bottom of the washing area 8 . The cleaning tank 2 is further provided with a low boiling point organic solvent tank 26 located adjacent to the cleaning area 8 of the tank body 4. A weir 28 of a predetermined height is formed between the tank 26 and the cleaning area 8.

In the finishing area 10 of the cleaning tank 2, there is a finishing spraying means 3.
0 is associated. This finishing injection means 30 includes a plurality of injection nozzles 32 and a pump 34.

The plurality of injection nozzles 32 are arranged on the intermediate side wall of the tank body 4 at appropriate intervals in the horizontal and vertical directions. The inlet side of the pump 34 is connected to the tank 26 by a line 36.
The outlet side is connected to the injection nozzle 32 by a line 38. A condensing cooling means 42 having a refrigerant circulation pipe 40 extending along the inner surface of the intermediate side wall of the tank body 4 is further disposed in the processing area IO.

The front and rear ends of the drying zone 12 of the cleaning tank 2 are extended forward and rearward of the finishing zone 1O, and the lower ends of the front and rear ends of the drying zone 12 extend in the width direction. The existing collection/#44 has been formed. A condensing cooling means 48 having a refrigerant circulation pipe 46 extending above the collection groove 44 and along the inner surface of the upper side wall of the tank body 4 is also provided in the drying area 12 .

Inside the tank body 4 of the cleaning tank 2, a packet 50 for holding a member to be cleaned, that is, an object to be cleaned, is arranged. This bucket 50 is suspended by a packet moving means 52, generally indicated by the number 52, so as to be movable up and down. The bucket) 50 itself is configured so that the cleaning liquid sprayed from the spray nozzle 16 in the cleaning zone 8 or the low boiling point organic solvent sprayed from the spray nozzle 32 in the finishing zone IO can collide with the desired surface of the object to be cleaned, as will be described later. The bucket 50 may have any form as long as it can hold the object to be cleaned.6 For example, the bucket 50 has a bottom plate in which a plurality of openings (not shown) can be formed as necessary, Various members such as a round bar or wire mesh for holding objects to be cleaned such as an ink tray, an ink pipe, and an applicator in a printing machine are fixed to this bottom plate by appropriate means such as welding. In FIG. 1, for convenience, the object to be cleaned held by various members fixed on the bottom plate is schematically illustrated as a whole by a two-point line 54.

The bucket moving means 52 in the illustrated example includes a pair of rotating shafts 5G disposed at the upper end of the tank main body 4 at a distance in the width direction (direction perpendicular to the plane of the paper in FIG. 1).
(only one of which is shown in FIG. 1). Each of the pair of rotating shafts 56 extends substantially horizontally from the upper end of the tank body 4 in the front-rear direction (left-right direction in FIG. 1), and its rear end penetrates through the tank body 4 and projects rearward.

The rear end portion of each of the pair of rotating shafts 56 is connected to a suitable transmission mechanism (
(not shown) to a rotary drive source 58, which may be an electric motor. The front half 60 and rear half 62 of the main parts of the pair of rotating shafts 56 extending inside the tank body 4 are provided with internal threads running in mutually opposite directions. Sliding blocks 64 and 66 having corresponding internal threads are screwed to the front half 60 and rear half 62, respectively. The sliding blocks 64 and 66 are connected to the link mechanism 6
8 to upright connecting pieces 70 formed on both sides of the bottom plate of the packet 50. The link mechanism 68 has a first pair of links 72 and 74, a second pair of links 76 and 78, and a third pair of links 80 and 82. The upper ends of the first pair of links 72 and 74 are pivotally connected to the sliding blocks 64 and 66, respectively, and the intermediate portions of the first pair of links 72 and 74 are pivotally connected to each other. The upper ends of the second link pairs 76 and 78 are pivotally connected to the lower ends of the first link pairs 72 and 74, respectively, and the intermediate portions of the second link pairs 76 and 78 are pivotally connected to each other. has been done. Further, the lower ends of the second link pairs 76 and 78 are connected to the third link pairs 80, respectively.
and 82, and the lower ends of the third link pair 80 and 82 are pivotally connected to the upright connecting piece 70. As described above, when the pair of rotary shafts 56 are rotated clockwise when viewed from the left in FIG. 1 by the rotary drive source 58, the sliding blocks 64 and 66 move in the directions indicated by arrows 84, respectively. The bucket 50 is thus forced to rise in a substantially vertical direction. Conversely, when the pair of rotating shafts 58 are rotated counterclockwise when viewed from the left in FIG. 50 is lowered in a substantially vertical direction.

The illustrated cleaning device is further equipped with a water separator 88 and an exhaust cooler 90. The inlet side of the water separator 88 is connected by a line 92 to the collecting groove 44 formed at the lower end of the drying zone 12 of the tank body 4, and the outlet side is connected to the tank 26 by a line 94. The inlet side of the exhaust body cooler 90 is connected to the upper part of the drying area 12 of the tank body 4 by a line 96, and the outlet side is connected to the tank 26 by a line 98.

Next, it can be carried out using the above cleaning device,
A preferred example of the cleaning method according to the present invention will be described.

First, the cleaning liquid bath 100 is generated by filling the cleaning liquid 8 in the tank body 4 with cleaning liquid. It is important that such a cleaning liquid contains a low boiling point organic solvent and a high boiling point organic solvent. Examples of low-boiling organic solvents generally include organic solvents with a boiling point of 100°C or less, such as alcohols such as methanol, ethanol, and isopropyl alcohol, and chlorinated hydrocarbons such as methylene chloride and 1°1.1-trichloroethane. It can be suitably used. The high boiling point organic solvent is generally an organic solvent with a boiling point of 100°C or higher, such as glycol ethers such as ethylene glycol methyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, polyethylene glycol monomethyl ether, and diethylene dioxide. can be suitably used. These low boiling point organic solvents and high boiling point organic solvents are not particularly limited as long as they are compatible with each other, and can be appropriately selected and mixed depending on the type of ink attached to the object to be cleaned. .

The mixing ratio of the low boiling point organic solvent and the high boiling point organic solvent may generally be about 3=7 to 7:3 in terms of weight ratio. The filling amount of the cleaning liquid is preferably such that the liquid level of the cleaning liquid bath lOO is somewhat below the upper edge of the weir 28, as shown in FIG.

Further, a tank 26 attached to the tank body 4 is filled with a low boiling point organic solvent 102 to produce a low boiling point organic solvent 102. This low boiling point organic solvent is preferably the same as the low boiling point organic solvent in the cleaning liquid 100 described above.

The low boiling point organic solvent can be filled until its liquid level matches the upper edge of the weir 28.

When the so-called preparatory operation is completed as described above, the cleaning operation of the object to be cleaned can be started.

First, the bucket 50 is raised by the bucket moving means 52 to the raised position indicated by the two-dot chain line 50A. Then, the door 6 is opened and the objects 54 to be cleaned, such as the ink tray, ink pipe, and applicator in the printing machine, are opened.
is loaded into the bucket 50. Next, the door 6 is closed to seal the cleaning tank 2, and then the bucket 50 is lowered, for example, to the lowest position shown by the solid line, and the object to be cleaned 54 is immersed in the cleaning liquid bath 100 present in the cleaning area 8. , thus starting the cleaning process. In order to improve the cleaning effect, the heating means 2 is heated before or after the object to be cleaned 54 is immersed.
4 to heat the cleaning liquid bath 100. Cleaning liquid bath 10
temperature higher than the boiling point of the low-boiling point organic solvent and lower than the boiling point of the high-boiling point organic solvent in
Preferably, the cleaning liquid bath 100 is heated to between 80°C and 80°C. During the cleaning process, the packet 50 is moved up and down as appropriate, for example, between the lowest position shown by the solid line and the position shown by the two-dot chain line 50B.In this way, the object to be cleaned 54 is moved in the cleaning liquid bath 100. As a result, the cleaning liquid flows appropriately over the surface of the object to be cleaned 54, thereby promoting the dissolution cleaning action and the separation cleaning action.

The reciprocating lifting distance of the object to be cleaned 54 in the cleaning liquid bath 100 is preferably 5 to 30 CIl, particularly 10 to 20 cm, the reciprocating lifting speed is preferably 5 to 20 m/min, and the reciprocating lifting period is Preferably it is 20 to 40 seconds. During the cleaning process, the pump 18 is further energized, and the cleaning liquid sucked from the cleaning liquid bath 100 through the line 20 is fed through the line 22 to the injection nozzle 16, and from the injection nozzle 16 to the object to be cleaned 54. is sprayed towards.

The sprayed cleaning liquid collides with the object to be cleaned 54 and applies a mechanical cleaning action to the object to be cleaned 54 . The spraying of the cleaning liquid may be started at the same time as the object to be cleaned 54 is immersed, or several minutes later. The spraying speed of the cleaning liquid may be about 5 to 20 m/sec. If desired, ultrasonic waves can also be projected onto the object 54 in the cleaning liquid to create an ultrasonic cleaning action.

When the cleaning process in the cleaning area 8 is completed, the packet 50 is raised to the position indicated by the two-dot chain line 50C,
The object to be cleaned 54 is removed from the cleaning liquid bath 100 and placed in the finishing area 10 .

A finishing process is then performed in this finishing area IO. In the finishing process, the pump 34 is energized, and the low boiling point organic solvent sucked from the low boiling point organic solvent reservoir 102 through the line 36 is delivered to the injection nozzle 32 through the line 38, and from the injection nozzle 32, the low boiling point organic solvent is sucked from the low boiling point organic solvent reservoir 102 through the line 36. It is injected towards the body 54.

The injection speed of the low boiling point organic solvent may be about 2 to 8 m/sec. In the finishing step, the object to be cleaned 54 is finished cleaned by the low-boiling organic solvent injected from the injection nozzle 32, and the vaporized low-boiling organic solvent rising from the cleaning liquid bath 100 present in the cleaning area 8 is also exposed. It acts on the body 54 to be cleaned, and thus the body 54 to be cleaned is sufficiently thoroughly cleaned. The low boiling point organic solvent injected from the injection nozzle collides with the object to be cleaned 54 and then flows down into the cleaning liquid bath 100 .

In addition, a portion of the vaporized low-boiling organic solvent in the finishing zone 10 is also
It is cooled and liquefied by the condensing cooling means 42 and flows down into the cleaning liquid bath 100. If desired, the object to be cleaned 54 can be periodically moved up and down in the finishing area IO during the finishing process.

When the finishing process is completed, the packet 50 is shown along the two-dot chain line 50.
The object to be cleaned 54 is raised to the position indicated by A and positioned in the drying area I2. And this dry area I2
In the drying process carried out in , the object to be cleaned 54 is maintained in the drying area 12 for a required period of time to be sufficiently dried. A part of the vaporized low-boiling point organic solvent that has risen to the drying zone 12 is cooled and liquefied by the condensing cooling means 48, and then flows into the collection groove 4.
Flows down to 4. The low boiling point organic solvent collected in the collecting groove 44 flows through a line 92 to the water separator 88, where it is subjected to water separation, and then passes through the line 94 to the low boiling point organic solvent.
? It is returned to the 8-drug tank 26. Further, the gas containing the vaporized low-boiling organic solvent present in the drying zone 12 is discharged to the exhaust body cooler 90 through a line 96, and the low-boiling organic solvent cooled and liquefied here is discharged through a line 98. is returned to the low boiling point organic solvent tank 26 through. When the low boiling point organic solvent in the low boiling point organic solvent tank 26 becomes excessive, the weir 2
8 into the cleaning liquid bath 100 in the cleaning zone 8 . When the object to be cleaned 54 is sufficiently dried, the object to be cleaned 54 is taken out from the bucket 50 by opening 5i6.

If the cleaning liquid bath 100 itself becomes contaminated by repeatedly performing the above-described cleaning method, the cleaning liquid is drained from the cleaning area 8 of the tank body 4 through the waste liquid line 25, and a new cleaning liquid is added to the cleaning area 8. It should be supplied to

<Examples and Comparative Examples> Example 61 tt attached to a gravure printing machine coated with rubber-based and nitrified cotton yarn ink sold by Toyo Ink Co., Ltd.
A plurality of parts including the ink pan, ink pipe, and applicator are cleaned using the cleaning device shown in Figure 1 and in accordance with the cleaning method described with reference to Figure 1. , and washed under the following conditions.

+11 Scale of cleaning tank (depth/width) Cleaning area...1100 Dragons x 2400 Dragons Finishing area...1100 Dragons x 2400 Axis drying area... 1200mm x 2400mm (2) Number of injection nozzles/interval Vertical direction Horizontal cleaning area... 66 pieces 2001 @ 200 mm Finishing area...30 pieces 250■-2501 layer (3) Injection speed Cleaning area (cleaning liquid)...10 m/sec Finishing area (low boiling point organic solvent)...5 m/sec ( 4) Bucket lifting distance: 10 cvA Period: 20 seconds Speed: 6 m/min (5) Cleaning liquid bath composition Weight percentage: Methylene chloride: 50% Diethylene glycol 1,000 methyl ether ...50
% Temperature...(io"c (6) Approx. time Washing process (cleaning area residence time)...5 minutes Finishing process (
Finishing area l: fi residence time)... 1 minute Drying process (drying area residence time)... 1 minute The cleaning effect of the object to be cleaned is as follows:
It was as shown in the table.

This 1 Fresh 1 Washing was carried out in the same manner as in Example except that the washing liquid bath was maintained at 20° C. without heating. The cleaning effect on the object to be cleaned was as shown in Table 1 below.

Cleaning was carried out in the same manner as in the Example using Soji Soup. Its cleaning effect is
The results were as shown in Table 1 below.

Cleaning was carried out in the same manner as in the Examples except that a cleaning solution bath consisting only of methylene chloride was used. The cleaning effect on the object to be cleaned was as shown in Table 1 below.

Except for omitting the finishing process in the finishing area. table 34...Pump 42... Condensing cooling means 44... Collection groove 48... Condensing cooling means 50...Bucket 52...Bucket transportation means 54...Object to be cleaned 88...Water separator 90...Exhaust body cooler 100...Cleaning liquid bath 102...Low boiling point organic solvent reservoir

Claims (1)

[Scope of Claims] 1. Immersing the object to be cleaned in a cleaning liquid bath containing a low boiling point organic solvent and a high boiling point organic solvent, heating the cleaning liquid bath, and immersing the object to be cleaned in the cleaning liquid bath. and injecting a cleaning liquid into the cleaning liquid bath in which the object to be cleaned is immersed; A cleaning method comprising: a finishing step including spraying an organic solvent onto the object to be cleaned. 2. The cleaning method according to claim 1, wherein in the cleaning step, the cleaning liquid bath is heated to a temperature higher than the boiling point of the low-boiling organic solvent in the cleaning liquid bath and lower than the boiling point of the high-boiling organic solvent in the cleaning liquid bath. . 3. The cleaning method according to claim 1 or 2, wherein the low boiling point organic solvent sprayed onto the object to be cleaned in the finishing step is the same as the low boiling point organic solvent in the cleaning liquid bath. 4. A cleaning tank having a cleaning area located at the bottom and a finishing area located above the cleaning area, a bucket for holding objects to be cleaned disposed in the cleaning tank, and a bucket for moving the bucket up and down. a lifting means, a cleaning injection means for injecting a cleaning liquid containing a low boiling point organic solvent and a high boiling point organic solvent into the cleaning area, a finishing injection means for injecting a low boiling point organic solvent into the finishing area, and a cleaning injection means for injecting a low boiling point organic solvent into the finishing area; A cleaning device comprising: a heating means provided therein. 5. The cleaning device according to claim 4, wherein the cleaning tank has a drying area located above the finishing area, and a condensing cooling means is provided in the finishing area and the drying area. 6. The cleaning tank is equipped with a low-boiling organic solvent tank adjacent to the cleaning area via a weir of a predetermined height, and the low-boiling organic solvent condensed by the condensation cooling means in the drying area is 6. The cleaning device according to claim 5, wherein the low boiling point organic solvent is fed to the low boiling point organic solvent reservoir and the low boiling point organic solvent is supplied from the low boiling point organic solvent tank to the finishing injection means. 7. An exhaust body cooling means connected to the drying area of the cleaning tank is provided, and the vaporized low boiling point organic solvent in the exhaust body that has flowed into the exhaust body cooling means from the drying area is absorbed by the exhaust body cooling means. 7. The cleaning device according to claim 6, wherein the low boiling point organic solvent is cooled in a tank and then fed to the low boiling point organic solvent tank.