JPS6076346A - Drying device for printing paper - Google Patents

Abstract

PURPOSE:To arrange to reduce the difference of a moisture evaporation between a blank part and a printed part of paper by interposing an infrared ray dryer containing an infrared ray heater which wavelength is selectively absorbed into a printed part of paper instead of into a blank part, between a printing machine and a hot blast dryer. CONSTITUTION:An infrared ray dryer 11 interposed between a printing machine and a hot blast dryer 12 contains an infrared ray heater which wavelength is selectively absorbed into a printed part of printing paper instead of into a blank part. Printing paper 19 is first introduced into an infrared by dryer 11 and shows a temperature increase only in the printed part by an infrared by of the heater 13 through a reflector 14. In this case, a service voltage to the heater 13 is regulated so that a solvent in ink may be heated to 80-100 deg.C, temperatures at which the solvent begins evaporating. Next, the printing paper enters a hot blast dryer 12 where the solvent evaporates and dries under hot blast. Thus it is possible to keep the hot blast at low temperature and consequently restrict moisture evaporation in the blank part to a larger extent than before. Thus the difference in moisture content between the blank part and the printed part is reduced and the generation of wrinkles is also minimized.

Description

[Detailed description of the invention] The present invention relates to a printing paper drying device.

In order to evaporate the ink solvent on printing paper (web) after printing with a printing machine, it is necessary to heat the web with a dryer.

Figure 1 shows a conventional printing paper dryer, in which (1) is the web, (2) is the air supply blower, (3) is the burner, (4) is the nozzle, (5) is the exhaust blower, and the web ( ], ) are uniformly hit with hot air from the nozzle (4) for both the blank paper section and the printing section.
The amount of water evaporation is different between the printed area with an ink film and the blank area without an ink film, and naturally more moisture evaporates in the blank area, resulting in a difference in web shrinkage between the blank area and the printed area.
Wrinkles appear on the printed part. These wrinkles become permanent wrinkles as the ink film is fixed (set), and so-called "elbow wrinkles" occur.

The present invention was proposed in order to solve these problems, and includes an infrared dryer interposed between the printing machine and the hot air dryer, and the infrared dryer has an infrared dryer that can print more than the blank area. The present invention relates to a printing paper drying device characterized in that it has a built-in infrared heater with a wavelength that is selectively absorbed in a portion thereof.

Since the printing paper drying apparatus according to the present invention is configured as described above, the printing paper leaving the printing machine is not directly fed to the hot air dryer as in the conventional case, but is placed between the two dryers. It is sent to an intervening infrared dryer. Since the infrared dryer has a built-in infrared heater with a wavelength that is selectively absorbed by the printing section compared to the blank section, the temperature of only the printing section increases. In this state, the printing paper is sent to a hot air dryer and dried with hot air, so that the difference in the amount of water evaporation between the blank paper area and the printed area is reduced, and wrinkles are also reduced.

The present invention will be described below with reference to the illustrated embodiments.

(11) is a hot air dryer interposed between a printing machine (not shown) and a hot air dryer (121), which is used to dry infrared rays at a wavelength that is selectively absorbed by the printing area compared to the blank area of the printing paper. Machine a□□□
is built-in. In the figure, α is a reflector.

In addition, 09 in the figure is the freon of the hot air dryer 02), θ6) is the burner, (17) is the nozzle, and (1 barrel is the exhaust blower).

Since the illustrated embodiment is configured as described above, the printing paper α printed by the printing machine is first dried by the infrared dryer (11
)to go into. The temperature of only the printing part increases by the infrared heater (131) of the printing paper, but the temperature of the printing part at the outlet of the infrared dryer αυ is set to about 80 to 100°C, at which point the solvent in the ink starts to evaporate. Adjust the supply voltage of the infrared heater 03).

At this time, the reflector (I4) is useful for improving the irradiation efficiency of the infrared heater 0:1.

The printing paper a9 leaving the infrared dryer 01) immediately enters the hot air dryer 01, where the hot air blows off the solvent and dries the ink.

This means that unlike conventional hot air dryers, infrared dryers Q,
Since the temperature of the printing part of the printing paper has already increased due to 1), the hot air temperature of hot air dryer a2 is 200 to 25
There is an advantage that the temperature can be reduced from about 0°C to about 150 to 200°C. In order to keep the temperature of the solvent in the hot air dryer (2) constant, a portion of the hot air is exhausted by the exhaust float 081.

Fresh air equivalent to the discharged hot air l is sucked in through the printing paper inlet/outlet loss slit (a) (20'), but the inlet slit (inlet slit) is installed close to the infrared dryer ← 1). Therefore, the air inside the infrared dryer (11) is also sucked in, which is useful for cooling the infrared heater (03) and improving the thermal efficiency of the hot air dryer (03).

In this way, the infrared rays radiated from the infrared heater of the infrared dryer α1) are selectively absorbed by the printed part of the printing paper H, and the low temperature of the hot air of the hot air dryer α prevents moisture evaporation in the white paper part. This is more suppressed than before, the moisture difference between the blank paper area and the printed area is reduced, and the occurrence of wrinkles is also reduced.

Infrared heaters (generally used in IJ homes emit infrared rays with a wavelength of 1 to 2 μm, but the infrared absorption characteristic of water is 21 hours).
n, and the infrared absorption property of the ink solvent is 3 to 6.
It is also possible to use a far-infrared heater that emits infrared rays with a wavelength of 6 to 100 μm, taking advantage of the fact that the wavelength is about μm.1 Next, an experimental example of the present invention will be described.

Printing paper Ql when a 100 KW infrared dryer and a conventional hot air dryer are combined, and the paper surface temperature at the outlet of the infrared dryer is adjusted to 80℃ and the paper surface temperature at the outlet of the hot air dryer is adjusted to 160℃. Fragments are shown in Figures 6 and 4. Figure 6 shows a cross section when dried using only a conventional hot air dryer.
FIG. 4 shows a cross section when dried using the drying apparatus of the present invention. According to this, it can be seen that the hijizawa is less than about 100m tall.

Although the present invention has been described above with reference to embodiments, the present invention is, of course, not limited to such embodiments, and can be modified in various ways without departing from the spirit of the present invention. .

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a conventional printing paper drying device, FIG. 2 is a vertical cross-sectional view showing an embodiment of the printing paper drying device according to the present invention, and FIG. 6 and FIG. 1 is a sectional view of a drying device and a printed paper dried in the drying device according to the invention; FIG. (II)...Infrared dryer, (12...Hot air dryer, (L□□□...Infrared heater, ■...Printing paper sub-agent Patent attorney Shigeru Okamoto, 6 outsiders No. 3 figure

Claims (1)

[Claims] An infrared dryer is interposed between the printing machine and the hot air dryer, and the infrared dryer has a built-in infrared heater with a wavelength that is selectively absorbed by the printed part compared to the blank part. Drying equipment for printing paper.