JPH05318710A - Method of washing printing machine - Google Patents

Abstract

PURPOSE:To remove ink liquid, dregs of an ink film and the like from the surface by spraying with high pressure fine particles having the properties of ordinary temperature sublimation on the surfaces of an impression drum of the printing machine, a furnisher roller, an ink pan or a doctor blade and like parts. CONSTITUTION:Fine particles of dry ice or like substances in the nature of sublimation at an ordinary temperature (15-25 deg.C) are sprayed with high pressure on an impression drum, a furnisher roller, a doctor blade and like parts and brought into collision thereto. In this way, the ink, paper powder or the like stuck to the surface of these bodies are removed in an extremely short time. In concretely terms, the impression drum 10 being subjected to washing after the completion of printing is dismounted from the printing machine and then washed by the use of highly pressurized fluid spray gun 30 containing dry ice fine particles. In this instance, on the tip end of a spray nozzle 22 of the spray gun 30, a slit 31 is provided which serves to spray highly pressurized air 32 containing dry ice fine particles. Then, the impression drum 10 is mounted on the support frames 39 of a support body 38 to be washed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink pan, a furnisher roll and a plate cylinder of a gravure printing machine; a plate cylinder, a doctor roll, a finisher roll and an ink pan of an offset printing machine; a hollow cylinder type printing of a screen printing machine. A method of cleaning a screen.

[0002]

2. Description of the Related Art In a gravure printing machine, it is necessary to wash the plate cylinder and the finisher roller when replacing the plate cylinder. Conventionally, as the cleaning method, a method has been adopted in which the plate cylinder is rotated at a low speed immediately after printing, and the cleaning solvent is dripping from the top with dew or the like to wet the plate surface and wiped off with a rag scratch or the like.

Further, the plate shaft supporting the plate cylinder and the wall of the shaft space on the side surface of the plate cylinder are heavily contaminated by ink splashes from the doctor, ink splashes from the ink in the ink pan, and a dry ink film. Therefore, it is difficult to wash easily. At present, we are trying to simplify the washing by winding paper tape around the shaft in advance and fitting a tube made of plastic sheet.

However, such a method for cleaning a plate cylinder is a complete manual work by an operator, and moreover, the plate cylinders of a plurality of printing units constituting the printing machine must be cleaned sequentially.
It is hard work and takes time. In addition, the solvent vapor is often sucked in during the work, which is not preferable for hygiene. Further, since it is a manual work, the solvent is often used more than necessary, which causes various problems such as cost increase.
Further, the work of winding a paper tape around the plate shaft and fitting the tube is also a dirty work, which is not a preferable method.

In order to solve this problem, while rotating the plate cylinder, a cleaning solvent is sprayed onto the plate shaft to clean the plate shaft, and at the same time, a finisher roller is pressed against the plate cylinder, and the ink is removed from the ink pan. Using the ink circulation system, a solvent is supplied between the plate cylinder and the finisher roller to roughly clean the plate surface, and then a cleaning solvent is sprayed onto the plate surface for finish cleaning. It has been proposed (JP-A-62-87352, JP-A-4-85042).

This method has an advantage as an automatic means, but since it uses a solvent type cleaning liquid, it has a problem in environmental hygiene. In addition, there is a drawback that it takes several minutes to remove the film formed by the ink splash attached to the wall of the hollow shaft on the side surface of the plate cylinder. Similarly, for cleaning the ink pan, a method of spraying the cleaning liquid on the inner surface of the ink pan is proposed (Shokai 61-125435).
No.) but there are similar problems.

Further, in order to shorten the processing time, a cleaning liquid supplying means for supplying a cleaning liquid to the plate surface of the plate cylinder, and a plate used for scraping the ink from the plate surface are used.
Scraping means having a separable doctor, drying means for blowing air onto the plate surface to dry, and control means for controlling the operations of the cleaning liquid supply means, scraping means and drying means in association with each other. An automatic plate cylinder cleaning device has been proposed (Japanese Patent Laid-Open No. 63-295262), and it is described that the plate cylinder can be cleaned in 1 minute and 25 seconds.

However, similarly, it is not enough to use an organic solvent as a cleaning liquid and to remove the ink film adhered to the plate cylinder shaft. On the other hand, in an offset printing machine, paper dust and foreign matter in the ink adheres to the roller, or a dried ink film adheres to the roller. To remove them, a doctor blade is used to remove them on the doctor roll.

By the way, the doctor roll is a roll whose inside is made of steel and whose surface is copper-plated, and the doctor blade is made of a thin plate made of spring steel which is chrome-plated. It is replaced every 2 to 4 weeks because it is worn away by foreign matter, paper dust, and the like. Since this work is difficult, we propose a device that automatically sprays a cleaning agent (white kerosene or morpholine, a mixture of monoethanolamine, alcohol, and water) onto the tip of the blade or the inking roll with a spray nozzle ( JP-A-61-22950, 6
3-188050), but it is difficult to completely clean it.

As a method that does not use a cleaning liquid, a plate cleaning apparatus has been proposed (Japanese Patent Laid-Open No. 63-4948) in which high-pressure air is sprayed on the plate cylinder to remove paper dust, ink residue, and foreign matter on the plate cylinder. However, this is not enough for removal. Also,
In offset printing, the cleaning liquid, waste cloth, and metal spatula were used to manually remove the paper dust, foreign matter, and ink adhering to the plate cylinder and the doctor roll every time the printing item changed.
It had more than 10 minutes.

[0011]

DISCLOSURE OF THE INVENTION The present invention uses an ink pan, a plate cylinder, a finisher roll, an inking roll, a doctor roll, ink, ink film residue, paper dust, etc. in an extremely short time without using an ink cleaning liquid. It is an object of the present invention to provide a method for cleaning a printing machine that can remove the above.

[0012]

The present invention is a high-pressure jet of fine particles that sublime at room temperature onto the surface of a plate cylinder of a printing press, a finisher roll, an ink pan or a doctor roll.
It is intended to provide a method for cleaning a printing machine, which is characterized by removing deposits such as ink liquid, ink film residue, and paper dust from these surfaces.

[0013]

The fine particles having a subliming property at room temperature (15 to 25 ° C.) such as dry ice collide with the plate cylinder, the finisher roll, the doctor roll, the ink pan, etc. at a high pressure to adhere to the surface of these objects. The ink, paper dust, etc. that had been removed are removed in an extremely short time.

In particular, in the case where fine particles such as dry ice have a low sublimation temperature under atmospheric pressure of -78.5 ° C., the ink liquid is partially solidified rapidly by the sublimation heat of the dry ice that has collided, and Since the coefficient of thermal expansion of metal such as bread, plate cylinder and doctor roll is different from that of resin such as ink film, solidified ink film, paper dust, etc. will peel off from the surface of the object. It is easily removed, and is easily removed from the object by collision of sublimable fine particles and high pressure air.

The present invention will be described below with reference to the drawings. FIG. 1 is a side view of an ink supply device of an offset printing machine, FIG.
Is a perspective view of an ink supply device of a gravure printing machine, FIG. 3 is a perspective view of a high-pressure liquid jet gun containing dry ice particles,
4 and 5 are plan views of a high-pressure fluid manufacturing apparatus containing dry ice particles.

Explaining the ink supply device of the offset printing machine of FIG. 1, the ink L in the ink pan 1 is collected by a screw (not shown) and sucked by the pump 2, and the filter 3 removes paper dust and foreign matters in the ink. Then, the ink is ejected from the ink ejection nozzle 4 to the ink source roll 5. The ink supplied to the ink source roll 5 is made to have a constant film thickness by the ink supply blade 6 and the gap 6 ',
It is transferred to a high-speed delivery roller 7 at a different peripheral speed, and is supplied to the plate cylinder 10 via a doctor roll 8 and inking rolls 9a and 9b. Further, the printing paper 12 is passed through the blanket 11.
Is transcribed to.

Reference numeral 19 denotes a dampening water tank. The dampening water W adheres to the water source roll 18, is scattered by the rotation of the brush roll 13 and adheres to the water reciprocating roll 14, and the inking roll 9
The plate cylinder 10 through the swimsuit roll 15 located in front of a and 9b.
To form a water film on the surface of the non-image area of the plate to prevent the ink from transferring to the non-image area. Also plate cylinder 1
Excess water in the dampening water at 0 is transferred from the plate cylinder 10 to the inking rolls 9a and 9b through the inking rolls 9a and 9b.
Doctor roll 8 with excess ink after feeding to the upper plate
The residual water-containing ink transferred to the doctor roll 8 is scraped off by the history doctor blade 17, collected in the ink pan 1, and again sucked by the pump 2 and recycled.

By the way, the doctor roll 8 is a copper-plated roll (the inside is made of steel), and the history doctor blade 17 is a thin plate made of spring steel (SK-5, hardness Hv540) plated with chrome, and is held by the blade holder 16. , Remove excess ink, paper dust, and other stains on the roller. In the present invention, instead of the doctor blade 17, a high pressure fluid injection gun 30 of sublimable fine particles such as dry ice is used, or the doctor blade 17 and the high pressure fluid injection gun 3 are used.
0 is also used to reduce the burden on the doctor blade 17. If the nozzle 22 of the injection gun is installed so as to cover the vacuum duct 23, the foreign matter removed from the plate cylinder can be easily discharged.

When printing is completed, the plate cylinder 10 is replaced,
When cleaning the ink pan 1 to change the ink, the plate cylinder is removed from the shaft, the ink is removed from the ink pan, and the nozzle 22 of the high-pressure fluid jet gun 30 that can be carried at another site is used.
More dry ice fine particles are sprayed on the surfaces of these objects for cleaning. FIG. 2 is a perspective view of the gravure printing machine 24.
1 is an ink pan, L is a gravure printing ink, 8'is a finisher roll, 10 is a plate cylinder, 25 is a resin film 1
2 is a pressure cylinder for pressing 2'to the plate cylinder, 22 is a nozzle of a spray gun of dry ice fine particles, 23 is a vacuum duct, and 26 is a suction hose. The injection gun 30 is connected by a hose to the high-pressure dry ice particle flow generator shown in FIG. 4 (the hose is omitted in FIG. 2).

In FIG. 2, a plurality of nozzles of a gun 30 for injecting high-pressure air containing dry ice particles are provided along the axial direction of the plate cylinder 10 over the entire width of the plate, and a plurality of vacuum ducts 23 are provided. Is formed so as to cover all the nozzles for injecting high-pressure air containing the dry ice particles. This high-pressure air jet nozzle is used for the plate cylinder 10.
Is provided on the upstream side with respect to the rotating direction of No. 1, and is attached so that the high-pressure air containing the jetted dry ice particles hits the plate surface 3 at an angle of 90 ° to 170 ° with respect to the tangential direction of the plate surface. The injection angle of high-pressure air is 9
The cleaning power is strongest at 0 °, but 100 ° to 110 °
In this case, paper dust, ink residue, etc. are more convenient because they are easily scattered and scattered in a certain direction.

The vacuum duct 23 is provided on the downstream side with respect to the rotation direction of the plate cylinder 10, and is attached so as to form an angle of 0 ° to 90 ° with respect to the tangential direction of the plate surface. The portions of the left and right side plates 27 of the vacuum duct 23 adjacent to the plate cylinder 10 have an arc shape according to the shape of the plate cylinder 10, and the ink that is scattered by ejecting high-pressure air containing dry ice particles. The distance from the plate cylinder 10 is minimized so that dust or paper dust does not fly out of the vacuum duct 23.

FIG. 3 shows that after the printing is completed, the plate cylinder 10 used for cleaning is removed from the printing machine before being stored in a warehouse, and is cleaned by using a high-pressure fluid jet gun 30 containing dry ice particles that can be carried in another room. It is a figure which shows the state which is doing. A slit 31 for injecting high-pressure air 32 containing dry ice particles is provided at the tip of the ejection nozzle 22 of the injection gun 30, and the slit 31 has a particle size of 1 to 6 mm and a length of 1 to 40 mm, and a dry ice pellet and compressed air (3 It leads to a pipe 33 which supplies a mixture of -30 kg / cm ² G). The slit 31 has a clearance of 2 to 5 mm, a length of 20 to 1000 mm, and has a circular cross section at a midway 34. The box 35 has an air amount throttle valve, and the area of the slit is adjusted by a trigger 36 provided near the handle 37 to determine the injection amount of dry ice particles.

The plate cylinder 10 is bridged on the support frame 39 of the support base 38 and washed. A method of producing high-pressure air containing dry ice fine particles supplied to the nozzle 22 of the injection gun 30 is described in USP 4,617,064, JP-A-63-1.
No. 27875. For example, as shown in Figure 4, liquid carbon dioxide to dry ice pellets (diameter 2 to 6 m
m, length 10 to 50 mm), which is mixed with compressed air, passes through the hose 104, and when jetted from the jet nozzle 22, the dry ice becomes fine particles of several microns to 1 mm, the plate cylinder, the ink pan, the fan It is washed by colliding with a shear roll or the like as a high-pressure air stream 32 containing dry ice particles.

That is, the liquid carbon dioxide is relatively high pressure (for example, about 21 kg / cm ² : 300) before being injected into the pellet extrusion cylinder 42 at atmospheric pressure through the inlet 41.
stored in a storage chamber at psi), the liquid carbon dioxide in the extrusion cylinder 42 changes to a solid state. Liquid carbon dioxide (CO ₂ ) in the storage chamber 49 is about 21 kg / cm ² and about −18 before being injected through the inlet 41 into the extrusion cylinder 42 maintained at atmospheric pressure.
It is maintained at ℃. Liquid CO due to a sudden drop in pressure
Solid part ₂ from the liquid phase-phase or "snow (sno
w) "phase crystallizes. Snowflake bodies are held by a screen (not shown) in the extrusion cylinder 42, which covers the outlet 42 through which the waste gas is discharged. Once a predetermined amount of the snow bodies in the cylinder 42 have been collected, the fluid ram 44 drives the piston forward in the extrusion cylinder, which compresses the snowflakes into a solid block which is then transferred to a die and breaker plate or pelletizer. Extruded via 45.

The solid dry ice pellets obtained are sent to the turning device 70 via a pellet conduit 48. During the initial start-up for cleaning the press, the extrusion cylinder 42 and pelletizer 45 are at the proper operating temperature (i.e., about-).
Must be cooled to 74 ° C). During this cooling time, incomplete pellets are often formed, so the opening of the turning valve causes the incomplete pellets to be discharged out of the apparatus. The diverter valve 72 is adapted to be hinged between open and closed positions (both positions are indicated by dashed lines in FIG. 4, closed positions are indicated by substantially vertical dashed lines).

Since it is preferable to maintain a portion of the pellet hopper 50 at a pressure just above atmospheric pressure, the diverting device 72 may have a sealing device (not shown) that provides a hermetic seal in both its open and closed positions. preferable. Such a sealing device is attached to the periphery of the diversion valve 72 so as to be tightly fitted to the waste chute 71 or to the inner surface of the diversion conduit 74 connecting the pellet conduit 48 and the upper part of the hopper 50. It is properly provided by a flexible sealing ring made of silicone rubber. Extruding cylinder 42, pelletizer 4 once
When 5 and pellet conduit 48 are sufficiently cooled, turning valve 72 is closed and pellets flow directly into the hopper where they accumulate for subsequent discharge.

The hopper 50 has the function of providing surge capacity to the device 40 when in use, and high and low level sensors (51 and 52) for indicating the relative level of pellets stored therein. Have. The pellets flow from the hopper 50 by gravity through a gravity feed chute 53 to a pellet receiving station 54. At the pellet receiving station 54, the pellets are gravity fed to the pellet feeder 60 and laterally transferred to the pressure delivery system of the apparatus.

FIG. 5 shows an enlarged sectional view of the pellet feeder 60. Hopper 50 and its gravity feed chute 53
Is connected to the top of the supply manifold or block 61. The pellets flow from the gravity feed chute 53 to the feed chute extension portion 62, and a stirring device 55 is provided therein so that the pellets freely flow from the hopper 50 to the pellet feeding device 60.

The receiving station 63 is in communication with the feed bar channel 64. The supply bar 90 is shown mounted reciprocally within the supply bar channel 64 and attached to the reciprocating device 110 at a connection point 92. The reciprocating device 110 is shown mounted to the rotating shaft 102 at a point offset from the center of the cam 101, thereby achieving a pure sinusoidal transition pattern and providing the feed bar 90.
A reciprocating force is applied to. The feed bar 90 includes a substantially cylindrical vertical transfer hole 91. The transfer hole 91 is alternately indexed to the receiving station 63 and the discharging station 66 when the supply bar 90 is reciprocated by the circular cam 101. Thus, the transfer hole 91 is aligned with the receiving station 63, which is gravity fed and filled with pellets from the hopper. The filled transfer hole 91 is then reciprocally moved laterally to be indexed at the discharge station 66.

A suitable manifold device 87 is provided to gravity feed the pellets from the hopper 50 to a plurality of receiving stations 63 where a plurality of feed bars 90 are utilized. Similarly, there is a single manifold device 107 that is used to direct the pellets discharged at multiple discharge stations 66 to a single discharge hose and nozzle 105 with pressurized gas.

A pressurized gas supply source (not shown) is attached to the pressurized gas inlet 101 formed in the supply manifold 61 and its depending gas channel 102.
The gas channel 102 is vertically aligned with the discharge station 66, and when the transfer hole 91 is indexed to the discharge station 66, the carbon dioxide pellets in which the pressurized gas is held are discharged from the transfer hole 91 to the discharge station 66. Through the discharge coupling 103 via the discharge hose 1
It is transferred to the discharge nozzle 22 via 04.

Further, the eccentrically mounted circular cam travels sinusoidally, so that the supply bar 90 can be slightly stopped at both ends of the reciprocating travel. To prevent the possibility of moisture entering the system,
Maintain a small pressure in the hopper and feeder.
High pressure (approximately 10 to 20 kg / cm) to transfer the laterally transferred pellets from the discharge station to the discharge nozzle.
^{Since 2} G of air) is used, it is unavoidable to insulate the high pressure at the discharge station 66 from the low pressure at the receiving station 63. To provide this pressure differential isolation within the pellet feeder 60, the feed bar 90 includes a feed bar channel 64.
A fixed face seal 80 disposed adjacent the upper surface of the receiving station 6 and the receiving surface of the receiving station 6 at the lower surface of the channel 64, respectively.
3 and at least two upper and variably biased seals 81 and 83 located adjacent the discharge station 66.

The stationary seal 80 has openings corresponding to the receiving station 63 and the pressure gas (air) channel 102, respectively, through which the feed bar channel 6 is located.
It is designed to communicate with 4. The third opening is also shown in a state of being formed corresponding to the bleed-off hole 104 and the degassing channel 105, and the bleed-off hole 104 and the degassing channel 105 are the transfer holes 91.
Is designed to relieve residual pressure in the transfer holes when is reciprocated laterally from the dispensing station 66 to the receiving station 63. To provide an upward bias pressure to the seal 81, a bias pressure block 85 is shown which supports the variable bias pressure seal 81 from below and maintains a set of four upward pressure biases below. The spring 86 is provided. A gas vent hole 65 is formed through the lower portion of the supply manifold 61 and the bias pressing block 85. A corresponding opening 82 is formed in the seal 81 to allow venting therefrom during the filling operation. The vent holes 65 may be one or more small passages to provide direct fluid communication between the feed bar channels 64 and the surrounding atmosphere, and the transfer holes 91 may be slightly added when indexed to the receiving station 63. The pressurized hopper 50 forces a small amount of carbon dioxide gas to pass through the pellet received in the transfer hole 91, and the gas inside is forced out of the system through the gas vent hole 65. This prevents moist gas or air from entering the system.

A similar biasing pressure block 88 supports a seal 83 adjacent the dispensing station 66. Similarly, the seal 83 is formed with an opening 84 corresponding to the hole formed through the biasing pressure block 88 in alignment with the pressurized gas channel 102 in the axial direction. Block 88
Is biased upward by the four springs 89. Both biasing pressure blocks 85 and 88 include standard O-ring seals 87 to further reduce the possibility of atmospheric air entering the system.

It is preferred that multiple feed bars 90 be combined in a single pellet feed system 60. In addition, this type of feed bar is alternately reciprocated to give a relatively uniform lateral movement speed from the receiving station to the discharge station, and six horizontal feed bars may be combined so as to discharge the pellets at a uniform speed. Yes, in which case any one transfer hole 91 of this supply bar will fill the pellets at the receiving station 63 at any given time, and two will reciprocate in each direction between the receiving station 43 and the discharge station 46 (total). 4) and one discharges the pellets at the discharge station 46. This continuous, staggered pattern is effective for transferring and ejecting pellets at a relatively uniform rate through the system.

In use, sublimable carbon dioxide pellets are formed and sent to a receiving station 63 via a surge (pulsating) capacity hopper 50. A plurality of supply bars 90 each having a transfer hole 91 are reciprocated,
The transfer holes 91 are arranged so as to be alternately arranged in the receiving station 63 and the discharging station 66. The sublimable dry ice pellets are transferred through the transfer holes 9 of the supply bar 90 when each transfer hole is indexed into the receiving station 63.
It is gravity fed into 1. The reciprocating feed bar is then laterally reciprocated to transfer the pellet-filled holes from the receiving station 63 to the dispensing station 66. 10 to 50 kg / cm ² G of pressurized pressure transfer feed gas (preferably air) 200 is at the discharge station 66
Supplied at a capacity of ˜1500 m ³ / hour, pellets are discharged from the transfer hole 91 when the transfer hole is indexed at the discharge station. Then, the discharged pellets are transferred to the discharge nozzle 22 and collide with the surfaces of the plate cylinder, the ink pan, the finisher roll, etc. to be cleaned.

However, since the ink liquid is a liquid,
The injection pressure from the nozzle 22 of the injection gun 30 is 3 to 30.
kg / cm ² G, preferably 15~20kg / cm ² G, the mixing volume ratio of the dry ice and air 1: 10 to 10: 10, the injection amount of compressed air containing dry ice Bifunko is 200
2,000 kg / hour, preferably 200 to 400 kg / hour, 50 to 230 when converted to the solid content of dry ice
The amount is kg / hour, preferably 100 to 200 kg / hour.

[0038]

The present invention will be described in detail below with reference to examples. Example 1 Shown Carbonic Acid Co., Ltd.'s cold jet (COLD JET;
A trade name) QSI-350 type was used, and the injection gun shown in FIG. 3 was attached thereto.

A gravure printing machine manufactured by Mitsubishi Heavy Industries, Ltd. and a gravure printing ink “NEW” manufactured by Toyo Ink Mfg. Co., Ltd.
LPR Super Ink "(trade name) diluted solvent thinner SL
Diluted to a concentration of 60% with 302, and used as a polypropylene-based synthetic paper "Yupo F" from Oji Yuka Synthetic Paper Co., Ltd.
PG60 "(trade name) is subjected to monochromatic solid printing (the amount of ink applied to the plate cylinder is about 1.2 g / m ² ) and after printing is completed, the plate cylinder (160 mmφ diameter, 1200 mm length) is removed from the printing machine. Insert a bridge support shaft into the hollow shaft center of the plate cylinder, bridge it to a stand, and use the above injection gun to supply a dry ice / compressed air weight ratio of 50/50, injection pressure of 17 kg / cm ² G, and supply. Quantity 3
60kg / hour (Solid amount of dry ice is about 170kg /
High pressure air (17 mm) containing dry ice fine particles so that the tip of the nozzle is within 50 to 200 mm of the plate cylinder.
(kg / cm ² G) was sprayed onto the surface of the plate cylinder on which the ink liquid was adhered to wash.

Approximately 40 minutes for cleaning the surface of the printing cylinder
It took seconds. Further, it took about 65 seconds to clean the side surface of the plate cylinder and the hollow shaft surface (removal of foreign matter) to which the ink film dust of the plate cylinder is attached. At the same time, when an empty ink pan with the gravure printing ink liquid transferred to the container was washed under the same conditions, about 6
Cleaning was completed in 0 seconds.

Comparative Example 1 A printing cylinder and an ink pan of the same gravure printing machine as in Example 1 were cleaned after printing by an experienced printing machine using a waste cloth soaked with thinner to remove ink liquid and foreign matters. It took about 190 seconds to clean the printing surface of the plate cylinder, about 300 seconds to clean the side surface of the plate cylinder, and about 250 seconds to clean the ink pan.

Comparative Example 2 As a high-pressure fluid to be sprayed, 1 containing no dry ice
The plate cylinder and ink pan were washed in the same manner as in Example 1 except that high pressure air of 7 kg / cm ² G was used. It took about 75 seconds to remove the ink liquid on the printing surface of the plate cylinder. For removing foreign matters such as ink film dust on the side surface of the plate cylinder, dust was still left even after high-pressure air was blown for 300 seconds. For the ink pan, the ink liquid could be removed, but foreign matter such as ink film dust adhering to the ink pan was still left after the high-pressure air was blown for 300 seconds.

Example 2 Offset printing ink "TSP" manufactured by Toyo Ink Mfg. Co., Ltd.
-400 "(trade name) and an offset four-color printing machine manufactured by Komori Printing Co., Ltd., and four colors (black, blue,
(Red, yellow) Offset printing was performed, and after the printing was completed, the plate cylinder was removed from the printing machine, bridged on a stand, and the plate cylinder was washed using the spray gun used in Example 1. It took about 55 seconds to remove the ink liquid and foreign matter on the surface and about 70 seconds to wash the side surface.

COMPARATIVE EXAMPLE 3 In Example 2, the plate cylinder for offset printing was cleaned by wiping with a waste water soaked with white kerosene by a skilled printing engineer. It took about 170 seconds to clean the printing surface. It took about 200 seconds to wash.

[0045]

According to the method of the present invention, the printing machine can be cleaned in an extremely short time, and since dry ice sublimes at room temperature, it is easy to clean up after cleaning.

[Brief description of drawings]

FIG. 1 is a side view of an ink supply device of an offset printing machine.

FIG. 2 is a perspective view of an ink supply device of a gravure printing machine.

FIG. 3 is a perspective view of a high-pressure fluid injection gun containing dry ice particles.

FIG. 4 is a plan view of a high-pressure fluid manufacturing apparatus containing dry ice particles.

5 is a partial cross-sectional view showing the pellet supply device in FIG.

[Explanation of symbols]

 1 Ink Pan 8 Doctor Roll 8'Furnisher Roll 10 Plate Cylinder 22 High Pressure Fluid Injection Gun Nozzle 23 Vacuum Duct 24 Gravure Printing Machine 30 High Pressure Fluid Injection Gun 32 High Pressure Air Flow Containing Dry Ice Fine Particles 42 Extrusion Cylinder 45 Pelletizer 49 Liquid Carbonate Gas storage room 50 Hopper 60 Pellet supply device 102 Pressure gas channel

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kouichi Tada 3-3-23, Misaki-cho, Chiyoda-ku, Tokyo Within Showa Carbonate Co., Ltd.

Claims (2)

[Claims] 1. A plate cylinder of a printing press, a finisher roll,
A method for cleaning a printing machine, which comprises ejecting fine particles that sublimate at room temperature onto a surface of an ink pan or a doctor roll under high pressure to remove deposits such as ink liquid, ink film residue, and paper dust from the surface. 2. The sublimable fine particles are dry ice fine particles, the injection pressure is 3 to 30 kg / cm ² G, the dry ice / air weight ratio is 1/10 to 10/10, and the pressure fluid containing the dry ice fine particles is The cleaning method according to claim 1, wherein the injection amount is 200 to 2,000 kg / hour.