JP2582627B2 - Cleaning method and apparatus - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a cleaning method and an apparatus 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 pipe, and an applicator are detachably mounted. In such multi-color printing with a gravure printing machine, printing for each color is repeatedly performed for a required number of colors, but when changing the printing color, various members to which the printing ink used in the previous printing is attached are used. It is necessary to remove and wash. Therefore, as a method for cleaning the above members in a printing machine,
(A) A simple immersion method in which a member to be cleaned is simply immersed in a cleaning liquid bath such as an organic solvent, and (b) a spray method in which a cleaning liquid is sprayed on the member to be cleaned have been proposed and put to practical use.

However, the simple immersion method has poor cleaning efficiency and requires immersion for an extremely long period of time, and even in such a case, it is not always possible to sufficiently sufficiently clean. On the other hand, in the above-mentioned spray method, even if the cleaning liquid is sprayed from various methods, particularly when the member to be cleaned has a complicated shape, a portion where the cleaning liquid does not directly collide remains.
Therefore, the cleaning is incomplete. Because of this, the printing industry has not been able to avoid manual cleaning operations using cleaning brushes in addition to or instead of cleaning by the simple dipping method or the spray method. The manual cleaning operation is not only complicated but also has a hygienic problem due to an organic solvent used as a cleaning liquid.

<Problems of the Invention> In order to solve the above-mentioned problems in the prior art, the present inventors have previously described in Japanese Patent Application No. 216498/1987 a drawing in which a member to be cleaned, that is, an object to be cleaned was placed in a cleaning liquid bath. In addition to being immersed in the cleaning solution, a unique cleaning method for injecting the cleaning solution into the cleaning solution bath while moving the object to be cleaned in the cleaning solution bath, and a cleaning apparatus convenient for carrying out such a cleaning method have been proposed.

According to the above-described cleaning method and cleaning apparatus proposed by the present inventor, the specific cleaning body can be cleaned significantly better than the conventional simple immersion method and spray method. However, such a cleaning method and a cleaning apparatus are still not sufficiently satisfactory, and according to the experience of the present inventors, sufficient satisfactory results may not be obtained depending on the type of printing ink and the like. .

Therefore, a main technical problem of the present invention is to further improve the above-described cleaning method and cleaning device proposed by the present inventors so that a more excellent cleaning effect can be achieved. .

<Means for Solving the Invention> The present inventors have conducted intensive research and experiments and found that
In the cleaning step, the cleaning liquid bath in which the object to be cleaned is immersed is made to contain a low-boiling organic solvent and a high-boiling organic solvent, and an improvement of heating the cleaning liquid bath is added, and further, after the cleaning step, It has been found that the above technical problem can be achieved by removing the object to be cleaned from the cleaning liquid bath and performing a finishing step of spraying a low-boiling organic solvent onto the object to be cleaned.

That is, according to the present invention, the object to be cleaned is immersed in a cleaning solution bath containing a low boiling point organic solvent and a high boiling point organic solvent, the cleaning solution bath is heated, and the cleaning object bath is washed in the cleaning solution bath. Moving the cleaning object, and spraying a cleaning liquid into the cleaning liquid bath in which the object to be cleaned is immersed; and removing the object to be cleaned from the cleaning liquid bath after the cleaning step, and having a low boiling point. A finishing step including spraying an organic solvent onto the object to be cleaned.

Further, according to the present invention, as a cleaning apparatus suitable for carrying out the above-described cleaning method, a cleaning tank having a cleaning liquid positioned on a base and a finishing area positioned above the cleaning liquid, and disposed in the cleaning tank. Cleaning object holding bucket, bucket elevating means for moving the bucket up and down, cleaning jet means for jetting a cleaning liquid containing a low boiling organic solvent and a high boiling organic solvent to the cleaning liquid, and a low boiling organic A cleaning device is provided, comprising: a finishing spraying means for spraying a solvent to the finishing zone; and a heating means arranged in the cleaning zone.

Preferred embodiments of the present invention Hereinafter, preferred embodiments 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 apparatus constructed in accordance with the present invention. The illustrated cleaning apparatus includes a cleaning tank indicated by reference numeral 2 as a whole. This washing tank 2
Includes a tank body 4 having a substantially rectangular parallelepiped shape, and an opening / closing door 6 provided on an open upper surface of the tank body 4. The rear edge (right end in FIG. 1) of the door 6 is pivotally attached to the tank body 4 and is pivotally opened and closed between a closed position indicated by a solid line and an open position indicated by a two-dot chain line. The tank body 4 includes a cleaning area 8 located at a lower portion, a finishing area 10 located above the cleaning area 8, and a drying area 12 located further above the finishing area 10.
And stipulates.

In connection with the cleaning area 8 of the cleaning tank 2, a cleaning jet means 14 is provided. The cleaning / injection means 14 includes a plurality of injection nozzles 16 and a pump 18. The plurality of injection nozzles 16 are disposed on the lower side wall of the tank main body 4 at appropriate intervals in the horizontal and vertical directions. The inlet side of the pump 18 is connected to the washing zone 8 by a line 20, and the outlet side is connected to the injection nozzle 16 by a line 22. A heating means 24 is provided at the bottom of the washing area 8. A waste liquid line 25 having an open / close 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 organic solvent tank 26 located adjacent to the cleaning area 8 of the tank body 4. A product 28 having a predetermined height is formed between the tank 26 and the washing area 8.

The finishing area 10 of the washing tank 2 is associated with a finishing spraying means 30. The finishing injection means 30 includes a plurality of injection nozzles 32 and a pump. The plurality of spray nozzles 32 are disposed on the side wall of the intermediate portion 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. The finishing zone 10 is further provided with a condensing cooling means 42 having a refrigerant circulation pipe 40 extending along the inner surface of the intermediate portion side wall of the tank body 4.

The front end and the rear end of the drying zone 12 of the washing tank 2 are extended forward and rearward from the finishing zone 10, and extend in the width direction at the front end and the rear end of the drying zone 12 in the width direction. An existing collecting groove 44 is formed. The condensing cooling means 48 having a refrigerant circulation pipe 46 extending above the collecting groove 44 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 washing tank 2, a bucket 50 for holding a member to be washed, that is, an object to be washed, is disposed. The bucket 50 is suspended so as to be able to move up and down by bucket moving means 52 indicated by reference numeral 52 as a whole. bucket
The injection nozzle 16 itself is located in the cleaning zone 8 as described later.
Cleaning liquid or any form as long as the low-boiling organic solvent injected from the injection nozzle 32 in the finishing area 10 can hold the object to be cleaned so that it can collide with a required surface of the object to be cleaned. Is fine. For example, bucket 50
Has a bottom plate in which a plurality of openings (not shown) can be formed as necessary, and the bottom plate is provided with an object to be cleaned such as an ink tray, an ink pipe, and an applicator in a printing press. Various members such as a round bar or gold steel for holding are fixed by appropriate means such as welding. First
In the figure, for the sake of convenience, the object to be cleaned held by various members fixed on the bottom plate is schematically illustrated by a two-dot chain line 54 as a whole.

The bucket moving means 52 in the illustrated example includes a pair of rotating shafts 56 arranged at an upper end of the tank body 4 at intervals in a width direction (a direction perpendicular to the paper surface in FIG. 1).
(Only one of them is shown in FIG. 1). Each of the pair of rotation shafts 56 extends substantially horizontally in the front-rear direction (the left-right direction in FIG. 1) at the upper end of the tank body 4,
The rear end portion penetrates the tank body 4 and projects rearward.
The rear end of each of the pair of rotating shafts 56 is connected to a rotary drive source which may be an electric motor via a suitable transmission mechanism (not shown).
Drive-coupled to 58. Male threads in opposite directions are engraved on the front half 60 and the rear half 62 of the main parts of the pair of rotating shafts 56 extending inside the tank body 4. And the first half
Sliding blocks 64 and 66 on which corresponding female threads are formed are screwed to the 60 and the rear half 62, respectively. The sliding blocks 64 and 66 are connected to the bucket by a link mechanism 68.
The bottom plate 50 is connected to upright connection pieces 70 formed on both sides of the bottom plate. The link mechanism 68 has a first link pair 72 and 74, a second link pair 76 and 78, and a third link pair 80 and 82. The upper ends of the first link pairs 72 and 74 are pivotally connected to the sliding blocks 64 and 66, respectively,
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. Have been. Further, the lower ends of the second link pairs 76 and 78 are pivotally connected to the upper ends of the third link pairs 80 and 82, respectively, and the lower ends of the third link pairs 80 and 82 are connected to the upright connecting pieces 70, respectively. Is pivotally connected to the As described above, when the pair of rotary shafts 56 are rotated clockwise as 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. Thus, the bucket 50 is raised in a substantially vertical direction. Conversely, when the pair of rotary shafts 58 are rotated counterclockwise as viewed from the left in FIG. 1 by the rotary drive source 58, the sliding blocks 64 and 66 are respectively indicated by arrows.
The bucket is moved in the direction shown at 86, thus lowering the bucket 50 in a substantially vertical direction.

The illustrated washing apparatus is further equipped with a water separator 88 and an exhaust body cooler 90. The inlet side of the water separator 88 is a line
It is connected to the collecting groove 44 formed at the lower end of the drying area 12 of the tank main body 4 by 92, 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, a preferred example of the cleaning method according to the present invention, which can be performed using the above-described cleaning apparatus, will be described.

First, the cleaning liquid 8 in the tank body 4 is filled with the cleaning liquid to generate the cleaning liquid bath 100. It is important that such a cleaning liquid contains a low-boiling organic solvent and a high-boiling organic solvent. As the low-boiling organic solvent, generally, an organic solvent having a boiling point of 100 ° C. or lower, for example, methanol, ethanol, alcohols such as isopropyl alcohol, methylene chloride,
Chlorine hydrocarbons such as 1,1,1-trichloroethane and the like can be suitably used. Further, as the high boiling organic solvent, generally, organic solvents having a boiling point of 100 ° C. or more, for example, glycol ethers such as ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, polyethylene glycol monomethyl ether, diethylene dioxide and the like. Can be suitably used. These low-boiling organic solvent and high-boiling organic solvent are not particularly limited as long as they have compatibility with each other, and can be appropriately selected and mixed according to the type of ink attached to the object to be cleaned. . In general, the mixing ratio of the low-boiling organic solvent and the high-boiling organic solvent may be about 3: 7 to 7: 3 by weight. The filling amount of the cleaning liquid is the first
As shown in the figure, it is preferable that the liquid level of the cleaning liquid bath 100 is slightly lower than the upper edge of the weir 28.

Further, a low-boiling organic solvent 102 is generated by filling a low-boiling organic solvent into a tank 26 attached to the tank body 4. The low boiling organic solvent is preferably the same as the low boiling organic solvent in the cleaning liquid 100. Low-boiling organic solvents have a weir 28
Can be filled until it meets the upper edge.

When the so-called preparatory operation is completed as described above, the operation for cleaning 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 an object to be cleaned 54 such as an ink tray, an ink pipe, or an applicator in the printing press is loaded into the bucket 50. Next, the cleaning tank 2 is closed by closing the door 6, and thereafter, the bucket 50 is lowered to, for example, the lowest position shown by the solid line, and the object to be cleaned 54 is immersed in the cleaning liquid bath 100 existing in the cleaning area 8. Thus, the cleaning process is started. Before or after the immersion of the object to be cleaned 54, the heating means 24 is energized to heat the cleaning liquid bath 100 in order to improve the cleaning effect. A temperature higher than the boiling point of the low-boiling organic solvent and lower than the boiling point of the high-boiling organic solvent in the cleaning liquid bath 100, generally 50 ° C to 90 ° C.
Preferably, the cleaning solution bath 100 is heated to a temperature of 55 ° C., particularly 55 ° to 80 ° C. In the cleaning step, the bucket 50 is moved up and down as appropriate between a lowermost position indicated by a solid line and a position indicated by a two-dot chain line 50B, for example, whereby the object to be cleaned 54 is moved in the cleaning liquid bath 100. As a result, the cleaning liquid flows appropriately on the surface of the object to be cleaned 54, thereby promoting the dissolution cleaning action and the separation cleaning action. The reciprocating vertical movement distance of the object to be cleaned 54 in the cleaning liquid bath 100 is preferably 5 to 30 cm, particularly preferably 10 to 20 cm, and the reciprocating vertical movement speed is preferably 5 to 20 m / min. Preferably, it is 20 to 40 seconds. At the time of the cleaning step, the pump 18 is further energized,
The cleaning liquid sucked from the cleaning liquid bath 100 via the line 20 is supplied to the injection nozzle 16 through the line 22, and the cleaning nozzle
It is sprayed from 16 toward the object to be cleaned 54. The jetted cleaning liquid collides with the object to be cleaned 54, and performs a mechanical cleaning action.
Add to 54. The injection of the cleaning liquid may be started at the same time as the immersion of the object to be cleaned 54 or several minutes after that. The jet speed after washing may be about 5 to 20 m / sec. If desired, the object to be cleaned in the cleaning liquid can be further irradiated with ultrasonic waves at 54 to produce an ultrasonic cleaning action.

When the above-described cleaning process in the cleaning area 8 is completed, the bucket 50 is raised to the position indicated by the two-dot chain line 50C, and the object to be cleaned 54 is taken out of the cleaning liquid bath 100 and positioned in the finishing area 10. Then, a finishing step is performed in the finishing area 10. In the finishing process, the pump
34 is energized to provide a low boiling organic solvent reservoir 10 via line 36.
The low-boiling organic solvent sucked from 2 is supplied to the injection nozzle 32 through the line 38 and is injected from the injection nozzle 32 toward the body 54 to be cleaned. The injection speed of the low boiling organic solvent is 2 to
It may be about 8m / sec. In the finishing process, the injection nozzle 3
The object to be cleaned 54 is finish-cleaned by the low-boiling organic solvent injected from 2 and the cleaning solution bath existing in the cleaning area 8.
The vaporized low-boiling organic solvent which rises from 100 also acts on the object to be cleaned 54, and thus the object to be cleaned 54 is sufficiently and thoroughly cleaned. The low-boiling 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. A part of the vaporized low-boiling organic solvent in the finishing zone 10 is also 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 moved up and down periodically in the finishing area 10 also during the finishing step.

When the finishing process is completed, the bucket 50 is set to the two-dot chain line 50A.
The object to be cleaned 54 is raised to the position
It is located at 12. In the drying step performed in the drying area 12, the object to be cleaned 54 is dried for a required time.
Keep at 12 and dry thoroughly. Part of the vaporized low-boiling organic solvent that has risen to the drying zone 12 is cooled and liquefied by the condensing cooling means 48 and flows down to the collection groove 44. The low-boiling organic solvent collected in the collecting groove 44 flows into a water separator 88 through a line 92, where it is subjected to a water separation action and then returned to a low-boiling organic solvent tank 26 through a line 94. 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 the line 96, and the low-boiling organic solvent cooled and liquefied here is supplied to the line 98. To the low-boiling organic solvent tank 26. When the low-boiling organic solvent in the low-boiling organic solvent tank 26 becomes excessive, the low-boiling organic solvent flows over the weir 28 into the cleaning liquid bath 100 in the cleaning area 8. When the cleaning target 54 is sufficiently dried, the door 6 is opened and the cleaning target 54 is taken out from the bucket 50.

If the cleaning liquid bath 100 itself is contaminated by repeatedly performing the above-described cleaning method, the cleaning liquid is discharged from the cleaning area 8 of the tank body 4 through the waste liquid line 25,
Then, a new cleaning liquid may be supplied to the cleaning area 8.

<Examples and Comparative Examples> Examples A plurality of units including an ink tray, an ink pipe, and an applicator, which are accessories of a gravure printing machine, to which rubber-based and nitrified cotton-based inks sold by Toyo Ink Co., Ltd. are attached. Was cleaned under the following conditions using a cleaning apparatus as shown in FIG. 1 and according to the cleaning method described with reference to FIG.

(1) Cleaning tank scale (depth / width) Cleaning area: 1100mm x 2400mm Finishing area: 1100mm x 2400mm Drying area: 1200mm x 2400mm (2) Number and spacing of spray nozzles Vertical horizontal cleaning area・ ・ 66 pieces 200mm 200mm finishing area ・ ・ 30 pieces 250mm 250mm (3) Injection speed Cleaning area (cleaning liquid) ・ ・ ・ ・ ・ ・ 10m / sec Finishing area (low boiling organic solvent) ・ 5m / sec (4) Bucket Elevation distance ··· 10 cm period · · · 20 seconds Speed · · · 6 m / min (5) Cleaning solution bath composition Weight ratio methylene chloride · · · 50% diethylene glycol Monomethyl ether 50% Temperature 60 ° C (6) Process time Cleaning process (time spent in cleaning area) 5 minutes Finishing process (time spent in finishing area) 1 minute Drying process (drying area) Staying time) 1 minute The cleaning effect of the object to be cleaned was as shown in Table 1 below.

Comparative Example 1 Washing was performed in the same manner as in Example except that the washing solution bath was maintained at 20 ° C. without heating. The cleaning effect of the object to be cleaned was as shown in Table 1 below.

Comparative Example 2 Cleaning was performed in the same manner as in Example except that the finishing step in the finishing area was omitted. The cleaning effect was as shown in Table 1 below.

Comparative Example 3 Cleaning was carried out in the same manner as in Example except that a cleaning liquid bath consisting only of methylene chloride was used. The cleaning effect of the object to be cleaned was as shown in Table 1 below.

[Brief description of the drawings]

FIG. 1 is a simplified sectional view showing a preferred embodiment of a cleaning apparatus constructed according to the present invention. 2 ... Cleaning tank 4 ... Tank body 6 ... Opening and closing door 8 ... Cleaning area 10 ... Finishing area 12 ... Drying area 14 ... Cleaning jetting means 16 ... Spray nozzle 18 ... Pump 24 ... Heating means 26 ... Low-boiling organic solvent tank 28 ... Weir 30 ... Finish injection means 32 ... Injection nozzle 34 ... Pump 42 ... Condensing cooling means 44 ... Collection groove 48 ... Condensing cooling means 50 ... Bucket 52 Bucket moving means 54 Body to be cleaned 88 Water separator 90 Cooler for exhaust body 100 Cleaning bath 102 Low-boiling organic solvent reservoir

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-291003 (JP, A) JP-A-60-87885 (JP, A) JP-A-57-136909 (JP, A) 128885 (JP, U)

Claims (7)

(57) [Claims] 1. An object to be cleaned is immersed in a cleaning solution bath containing a low-boiling organic solvent and a high-boiling organic solvent, the cleaning solution bath is heated, and the cleaning object is moved in the cleaning solution bath. And a cleaning step including spraying a cleaning liquid into the cleaning liquid bath in which the cleaning object is immersed. After the cleaning step, the cleaning object is taken out of the cleaning liquid bath, and a low-boiling organic solvent is removed. A finishing step including spraying the object to be cleaned. 2. The washing step according to claim 1, wherein the washing step comprises heating the washing bath to a temperature higher than the boiling point of the low-boiling organic solvent in the washing bath and lower than the boiling point of the high-boiling organic solvent in the washing bath. Cleaning method. 3. The cleaning method according to claim 1, wherein the low-boiling organic solvent sprayed onto the object to be cleaned in the finishing step is the same as the low-boiling organic solvent in the cleaning liquid bath. 4. A cleaning tank having a cleaning area located at a lower portion and a finishing area located above the cleaning area, a workpiece holding bucket disposed in the cleaning tank, and moving the bucket up and down. Bucket elevating means for washing, washing and jetting means for injecting a washing liquid containing a low-boiling organic solvent and a high-boiling organic solvent into the washing zone, finishing jetting means for injecting a low-boiling organic solvent into the finishing zone, A heating unit disposed in the cleaning area. 5. The cleaning apparatus according to claim 4, wherein said cleaning tank has a drying area located above said finishing area, and cooling means for condensation is provided in said finishing area and said drying area. . 6. A low-boiling organic solvent tank adjacent to the washing area is provided to the washing tank via a weir of a predetermined height.
The low-boiling organic solvent condensed by the condensing cooling means in the drying zone is fed to the low-boiling organic solvent reservoir, and the low-boiling organic solvent is supplied from the low-boiling organic solvent tank to the finishing injection means. The cleaning device according to claim 5. 7. An exhaust body cooling means connected to a drying area of the cleaning tank is provided, and the vaporized low-boiling organic solvent in the exhaust body flowing into the exhaust body cooling means from the drying area is removed by the exhaust gas. The cleaning device according to claim 6, wherein the cleaning device is cooled by a body cooling unit and fed to the low-boiling organic solvent tank.