JPH06118815A - Fixing device for wet type electrophotographic engraving machine - Google Patents

Abstract

PURPOSE:To obtain a fixing device which has high thermal efficiency for heating without soiling a printing plate and is not in danger of igniting by volatile matter but made compact, in wet type electrophotographic graving. CONSTITUTION:The fixing device is composed of a cylindrical heating drum 13 having the circumferential length longer than the maximum length of the processed printing plate 1 and rotated at peripheral speed equal to the carrying speed of the printing plate 1, a guide 12 guiding the printing plate 1 so as to cross the feeding path and ejecting path of the printing plate 1 each other and an air chamber 16 surrounding the outside of the heating drum 13 and uniformly blowing air against the surface of the fed printing plate 1 to carry its rear surface along the heating drum 13.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to wet electrophotographic processing processes.

[0002]

2. Description of the Related Art A conventional panel heater system or lamp heater system is generally used in a conventional fixing device for a wet electrophotographic plate making machine. FIG. 4 shows an outline of a panel heater type fixing device. The loading and unloading nip rollers 2 and 3 provided before and after the fixing unit.
And a panel heater 4 for heating the conveyed printing plate 1 from the lower surface, and a fan 5 for blowing air from above the printing plate. After the development, the wet printing plate 1 is carried in through the nip roller 2 and passes while the back surface is in contact with the panel heater 4. During that time, the volatile components evaporated from the surface are removed by the fan 5 and dried, and the dried toner particles are melted and fixed, and then discharged through the nip roller 3.

Further, FIG. 5 shows a fixing device of a lamp heater type, in which a lamp heater 6 is provided above a conveying surface as a heat source.
Is provided. In this case, the printing plate 1 carried in by the nip roller 2 is conveyed while being guided on the back side by a wire guide 7 having a small contact area. Then, the surface is heated by the radiation from the lamp heater 6 provided above the transport surface, and the drying and fixing are performed by the air blown from the fan 5, and the nip roller 3 carries the sheet out.

[0004]

When the above panel heater system is used, the plate 1 is fed in direct contact with the panel heater 4 while sliding on it, but the thermal efficiency of heating is good, but on the other hand, the printing plate is carried in. Contamination due to the toner liquid carried by the plate 1 accumulates on the surface of the panel heater 4, and this dirt is transferred to the back surface of the printing plate 1 and carried out. When the printing plates produced in this manner are stacked, the stains are further transferred to the surface of the printing plates and cause printing defects.

The lamp heater system eliminates the above-mentioned drawbacks and guides the back surface of the carried printing plate 1 by a wire guide 7 which has a small contact area and does not collect dirt, thereby preventing the back surface from becoming dirty. However, the radiant heating by the lamp heater 6 has poor thermal efficiency, and requires about twice as much electric power as the heat transfer by contact with the panel heater 4. Further, since the high-temperature lamp heater 6 is exposed to the volatile components that evaporate from the surface of the printing plate 1, there is a risk of ignition and a safety problem occurs. In addition, since drying and melting in the fixing step require a predetermined time, a space is required when the plate is conveyed on a straight line at a required speed, and the apparatus becomes large. The present invention has been made under the circumstances as described above, and an object of the present invention is to provide a fixing device which is safe, has high thermal efficiency, does not cause stains on a printing plate in wet electrophotographic platemaking, and is compact. is there.

[0006]

SUMMARY OF THE INVENTION The present invention relates to the structure of a fixing device for a wet electrophotographic plate making machine, and the above object of the present invention is to at least charge, expose, and expose a printing plate made of an electrophotographic photosensitive material. In a fixing device of a plate making machine including a wet toner developing and fixing step, a cylindrical heating drum having a circumferential length larger than a maximum length of a plate to be processed and rotating at a peripheral speed equal to a conveying speed of the plate, A guide that guides the plate so that the plate loading path and the plate loading path cross each other, and the back surface of the heating plate that surrounds the outside of the heating drum and blows air evenly over the surface of the loaded plate. Is achieved by the fixing device for an electrophotographic plate making machine, which is composed of an air chamber for carrying the sheet along with the heating drum.

[0007]

Since the printing plate advances in a loop along with the heating drum, the installation space of the apparatus is reduced. Here, since the circumferential length of the heating drum is larger than the length of the printing plate, the front and rear parts of the same printing plate do not intersect with each other at the intersection of the loops. Further, since the printing plate is pressed by the air from the air chamber and is conveyed together with the drum, there is no sliding as in the panel heater system, and stains and transfer are less likely to occur. The heating in this case is performed by heat transfer by contact with the heating drum, and since the printing plate wraps the outer circumference of the drum, the thermal efficiency is improved. Further, the evaporated volatile matter does not directly contact the heat source in the heating drum.

[0008]

The present invention will be described in detail below with reference to the drawings. FIG. 1 is a sectional view showing the main structure of the present invention. The printing plate 1 is carried in by the nip roller 11 and guided by a guide 12 formed of wire or the like to proceed to reach a cylindrical surface of a heating drum 13 having a cylindrical shape. The heating drum 13 is made of metal and has a heater 14 inside so that the cylindrical surface is heated. The circumference of the heating drum 13 is larger than the maximum length of the plate 1, and the transport speed of the plate 1 is It is designed to be rotationally driven at the same peripheral speed. An air knife 15 is provided near the exit of the guide 12 in the width direction of the printing plate 1, and an air chamber 16 is provided so as to surround the outer surface of the heating drum 13 on the cylindrical surface. The air chamber 16 has a large number of small holes 17 facing the heating drum 13, and is supplied with air heated by a heater 19 from a fan 18 as necessary, and the small holes 17 of the heating drum 13 are supplied. Air is blown toward the cylindrical surface.

In this way, the printing plate 1 exiting the guide 12
Is brought into close contact with the heated cylindrical surface of the heating drum by the air knife 15, is further pushed by the blowing air from the air chamber 16 and advances along the arc along with the rotation of the heating drum 13, and reaches the end of the air chamber 16. Reach
During that time, the front surface of the printing plate 1 is not contacted, but is heated from the back surface to dry and melt the toner particles to complete the fixing. The plate 1 that has been fixed is pressed by a pressing roller 20 provided near the outlet of the air chamber 16, guided by a guide 12 and conveyed through a nip roller 21. At this time, a loop is formed in the transport path of the plate 1 and an intersection of the guide 12 is formed. However, since the diameter of the heating drum is larger than the maximum length of the plate to be processed divided by π, the loading / unloading is carried out at the intersection. No crossing occurs.

Although the apparatus of the present invention does not slide between the heating drum 13 and the printing plate 1 and is less likely to collect dirt, as shown in FIG. 1 to keep the heater clean for a long period of operation. A cleaning pad 22 is attached above the heating drum 13 at a position where it does not come into contact with the printing plate 1, and the cylindrical surface of the heating pad 13 is wiped when the heating drum 13 rotates. Further, the surface of the cylindrical surface of the metallic heating drum 13 is treated with a fluororesin, so that the above-mentioned stain prevention effect becomes more remarkable.

FIG. 2 is a view showing a modification of the present invention, which is an upside down version of the apparatus shown in FIG. That is, when there is no space below the plate transporting surface between steps, it can be installed upside down as shown in FIG. 3 shows another modification of the present invention, in which the air chamber 16 in FIG. 1 is divided into two, and a pressing roller 23 is provided between the divided air chambers 161 and 162. That is, when the evaporation of the solvent is almost completed in the first half of the heating, the pressing roller 2 is
It is possible to place 3. Then, by dividing the air chamber in this way, the air chamber can be easily attached and detached from the side surface, and the maintainability is improved.

[0012]

As described above, according to the fixing device for a wet electrophotographic plate making machine of the present invention, there is no roller contact with the wet plate surface, and rubbing with the cylindrical surface of the heating drum occurs. Since there is no plate, stains on the plate can be eliminated, and since the plate comes in contact with the heating drum and wraps the outside thereof, the thermal efficiency becomes high. In addition, the transport path is looped to make the apparatus compact, and the heat source is built in the heating drum and does not touch the evaporated volatile matter, so that there is no danger of fire or the like.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the main structure of the present invention.

FIG. 2 is a sectional view showing a modified example of the present invention.

FIG. 3 is a sectional view showing another modification of the present invention.

FIG. 4 is a diagram for explaining a conventional panel heater type fixing device.

FIG. 5 is a diagram for explaining a conventional lamp heater type fixing device.

[Explanation of symbols]

 1 Printing Plate 2,3 Nip Roller 4 Panel Heater 5 Fan 6 Lamp Heater 7 Wire Guide 11,21 Nip Roller 12 Guide 13 Heating Drum 14 Heater 15 Air Knife 16,161,162 Air Chamber 17 Small Hole 18 Fan 19 Heater 20,23 Presser Roller 22 cleaning pad

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[Procedure amendment]

[Submission date] October 21, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

The present invention will be described in detail below with reference to the drawings. FIG. 1 is a sectional view showing the main structure of the present invention. The printing plate 1 is carried in by the nip roller 11 and guided by a guide 12 formed of wire or the like to proceed to reach a cylindrical surface of a heating drum 13 having a cylindrical shape. The heating drum 13 is made of metal and has a heater 14 inside so that the cylindrical surface is heated. The circumference of the heating drum 13 is larger than the maximum length of the plate 1, and the transport speed of the plate 1 is It is designed to be rotationally driven at the same peripheral speed. An air knife 15 is provided near the exit of the guide 12 in the width direction of the printing plate 1, and an air chamber 16 is provided so as to surround the outer surface of the heating drum 13 on the cylindrical surface. The air chamber 16 has a large number of small holes or slits 17 facing the heating drum 13, and receives supply of air heated by a heater 19 as needed from a fan 18 to receive the small holes or slits .
Air is blown from the rit 17 toward the cylindrical surface of the heating drum 13.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] Explanation of code

[Correction method] Change

[Correction content]

[Explanation of symbols] 1 plate 2, 3 nip roller 4 panel heater 5 fan 6 lamp heater 7 wire guide 11,21 nip roller 12 guide 13 heating drum 14 heater 15 air knife 16, 161, 162 air chamber 17 small hole or slit 18 Fan 19 Heater 20,23 Presser roller 22 Cleaning pad

Claims (2)

[Claims] 1. A printing plate made of an electrophotographic photosensitive material has a circumference length larger than the maximum length of the printing plate to be processed in a fixing device of a plate making machine including at least charging, exposure, wet toner development and fixing steps. A cylindrical heating drum that rotates at a peripheral speed equal to the transport speed of the printing plate, a guide that guides the printing plate so that the loading path and the unloading path of the printing plate cross each other, and the outside of the heating drum. Fixing for wet electrophotographic plate making machine characterized by comprising an air chamber in which air is uniformly blown to the front surface of the plate that has been carried in so that the back surface is conveyed along with the heating drum. apparatus. 2. The heating drum has a cylindrical surface processed with a fluororesin, and a cleaning pad is provided in contact with the cylindrical surface at a position where the cylindrical surface does not come into contact with the printing plate. The fixing device for a wet electrophotographic plate-making machine according to [4].