JP2729802B2 - Drying machine for web offset press - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a drying apparatus used for an offset rotary press.

[Conventional technology]

2. Description of the Related Art Conventionally, in an offset rotary press, a drying apparatus that blows hot air onto printing paper has been widely used. In the temperature control in this drying apparatus, the paper surface temperature at the outlet is usually measured by an infrared thermometer or the like, and the hot air temperature is controlled so that the temperature becomes constant.

In addition, the inside of one drying unit is divided into two zones upstream and downstream with respect to the running direction of the printing paper, that is, a first zone and a second zone. There is also known an apparatus in which drying is performed, and in a second zone, low-temperature hot air is used to slowly dry the printing paper so as to uniformly dry the printing paper and prevent occurrence of wrinkles. In such a drying apparatus divided into two zones, the hot air temperature in the first zone is set to a constant value in advance, and the hot air temperature in the second zone is controlled so that the paper surface temperature at the outlet is constant. I was

[Problems to be solved by the invention]

However, in such a conventional apparatus, the condition of the printing press is changed,
For example, when the type of printing paper, paper thickness, ink application amount, printing speed, and the like are changed, wrinkles may occur.

The present inventors have conducted various studies on the causes of the occurrence of the wrinkles and found that they were caused by an inappropriate drying speed in the first zone. To solve this,
The hot air temperature in the first zone may be adjusted to the optimum temperature each time the printing conditions are changed, but it is extremely difficult to find the optimum temperature for each printing condition.

The present invention has been made to solve such a problem.
It is an object of the present invention to provide a drying apparatus for an offset rotary press capable of always satisfactorily drying a printing paper regardless of a change in printing conditions.

[Means for solving the problem]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for drying an offset rotary printing press having a first zone and a second zone which are divided into upstream and downstream directions with respect to the running direction of printing paper in one drying apparatus. In the apparatus, two partition walls are provided at an interval between the first zone and the second zone, an opening is provided in a part of an outer surface of a region surrounded by the partition wall, and the opening is provided outside the opening. A first paper thermometer for measuring the paper surface temperature of the printing paper exiting the first zone, and a second paper thermometer for measuring the paper surface temperature of the printing paper exiting the second zone at the outlet of the second zone; The hot air temperature of the first zone is controlled according to the temperature measured by the first paper thermometer, and the hot air temperature of the second zone is controlled according to the temperature measured by the second paper thermometer. For offset rotary presses The gist of the 燥 equipment.

〔Example〕

 Hereinafter, embodiments of the present invention shown in the drawings will be described.

FIG. 1 is a schematic side view showing a drying device of an offset rotary press according to an embodiment of the present invention. In the figure, 1 is a printing machine, 2 is a blanket cylinder of a printing unit, 3 is a drying device, and 4 is a cooling roller. The inside of the drying device 3 is divided into two zones, that is, a first zone 5 and a second zone 6 in the upstream and downstream directions in the running direction of the printing paper 1. In the first zone 5 and the second zone 6, a number of nozzles 7,
The hot-air chambers 9 and 10 each having a fan 8 are provided in the hot-air chambers 9 and 10, respectively.
2, a hot air supply device having heating devices 13, 14, hot air circulation ducts 15, 16 and the like is connected. Heating device in this embodiment
13 and 14 are provided with burners 17 and 18.

There is a partition wall 1 between the first zone 5 and the second zone 6.
9 and 20 are provided, and an opening 21 is provided in a part of the outer surface of the area surrounded by the partition walls 19 and 20. Outside the opening 21, the surface of the printing paper between the first zone 5 and the second zone 6 is provided. A first paper surface thermometer 22 for measuring the temperature is provided. With this configuration,
The paper surface temperature can be measured while protecting the first paper surface thermometer 22 from the high temperature of the heating device. As the first sheet thermometer 22, for example, an infrared thermometer is used. The detected temperature of the first sheet thermometer 22 is input to the control device 23 and controls the burner 17 to control the hot air temperature. Second zone 6
A second paper surface thermometer 24 is provided at the outlet of the controller, and the detected temperature is input to a controller 25, which controls the burner 18 to control the hot air temperature.

According to the drying device having the above-described configuration, the printing paper 1 passes through the first zone 5 and the second zone 6 of the drying device 3 and is heated and dried by hot air blown out from the nozzles 7 and 8 in each zone. At this time, the paper surface temperature at the outlet of the first zone 5 is monitored by the first paper surface thermometer 22, and the burner 17 is controlled so that this temperature becomes constant, and the temperature of hot air supplied to the nozzle 7 is controlled. ing. The paper surface temperature at the outlet of the second zone 6 is monitored by a second paper surface thermometer 24, and the burner 18 is controlled so that the temperature is kept constant, and the temperature of the hot air supplied to the nozzle 8 is controlled. I have. Therefore, even if the printing conditions change, the first zone 5, the second zone 6
The printing paper passing through is dried in each zone so as to always have a predetermined temperature gradient. Thus, occurrence of elbows can be prevented.

〔The invention's effect〕

As described above, according to the present invention, a heating device for heating and drying printed paper with hot air is divided into a first zone and a second zone, and the paper surface temperature of the printed paper at the outlet of each zone is divided. Is measured, and the hot air temperature in each zone is controlled so that the temperature becomes a predetermined value. Therefore, regardless of the change in printing conditions, the paper surface temperature at the exit of the first zone and the second zone is always Each of them can be dried to a predetermined temperature, and has an effect that generation of wrinkles can be prevented. In addition, two partition walls are provided at intervals between the first zone and the second zone in order to arrange a first paper thermometer for measuring the paper surface temperature of the printing paper exiting the first zone. An opening is provided in a part of the outer surface of the area surrounded by the circle, and the first paper thermometer is arranged outside the opening, so that the first paper thermometer is protected from the high temperature of the drying device, and the paper temperature is improved. It also has the effect of being able to measure quickly.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing one embodiment of the present invention. 1 ... printing paper, 2 ... blanket cylinder, 3 ... drying device, 4 ...
... cooling roller, 5 ... first zone, 6 ... second zone, 7,8 ...
… Nozzle, 9,10 …… Hot air chamber, 11,12 …… Fan, 1
3,14 …… Heating device, 15,16 …… Hot air circulation duct, 17,18 ……
Burner, 19, 20 ... Partition plate, 21 ... Opening, 22 ... First paper thermometer, 23 ... Controller, 24 ... Second paper thermometer, 25 ...
…Control device.

Claims (1)

(57) [Claims] 1. A drying apparatus for an offset rotary printing press having a first zone and a second zone which are divided into upper and lower parts in a running direction of printing paper in one drying apparatus. Two partitions (19, 20) are provided at an interval between (5) and the second zone (6), and an opening (21) is provided in a part of the outer surface of the area surrounded by the partitions,
Outside the opening, there is provided a first paper thermometer (22) for measuring the paper surface temperature of the printing paper (1) exiting the first zone (5), and a second paper thermometer at the outlet of the second zone (6). Providing a second paper thermometer (24) for measuring the paper surface temperature of the printing paper exiting the zone, controlling the hot air temperature in the first zone in accordance with the temperature measured by the first paper thermometer, A drying device for an offset rotary press, wherein the hot air temperature in the second zone is controlled according to a temperature measured by a meter.