How to select UV curing device for the most popula

Rotary gravure printing on how to select UV curing device for the sample production line sent to be processed

on the basis of a correct understanding of UV curing process technology, the correct selection of UV curing device should also pay attention to the following principles

(1) determine the installation position. Generally, it is installed on the top of the oven of the concave printing color group for the following reasons: the installation space is large, and the installation of the paper passing roller and the cooling roller is convenient; Simple ventilation and heat dissipation; The paper path is long, which is conducive to the leveling of UV varnish. Of course, when determining the installation position of UV curing device, we should also consider the actual situation of different gravure machine models. If the space position is enough, it can also be installed behind the last color deck

(2) correctly determine the power and group number of UV lamps according to the speed and effect required for printing. The selected UV lamp has too much power or too many groups, which will cause unnecessary waste; If the power is too small or the number of groups is too small, the desired effect cannot be achieved

(3) the UV curing device should be designed to be movable as far as possible, so that it can be easily loaded and unloaded, and can be moved flexibly when products and processes change

(4) the rotary gravure printing speed is fast. When designing the UV curing device, its power should be divided into several grades according to the gravure printing speed, which can take into account the energy conservation and safety of production

(5) in view of the slow cooling speed of the air cooling method, there are safety hazards in the long-term operation of the UV curing device, it is recommended that the UV lampshade adopt the circulating water cooling method to prevent the safety hazards caused by the high UV curing temperature

(6) the UV curing device should be as far away from the ink tank and ink tank as possible, and the dynamic friction coefficient of the film surface should be relatively low, so as to avoid the drying and scaling of the ink after UV irradiation

(7) the safety and reliability of UV curing device must be guaranteed. The minimum cost of polyurethane exterior wall insulation material produced is about 1700 yuan/cubic meter to prevent fire

example of transformation scheme

1 Equipment status

a printing enterprise installed a wood grain paper 6-color rotary gravure press manufactured by Zhongshan Songde Packaging Machinery Co., Ltd. in February 2009. The basic characteristics of the equipment are as follows:

(1) mechanical shaft transmission, with a maximum mechanical speed of 150m/min

(2) the width is 1300mm

(3) the equipment adopts the paper threading method

(4) strengthened double ovens are used in all six color groups

2. Transformation purpose

the original six color decks of this equipment are electrically heated and hot-air dried, and can be printed with solvent based ink or water-based ink. In order to meet the market demand, a UV curing device is added, so that it can print prints that need UV varnish

3. According to the basic characteristics and process requirements of the equipment, considering the structure and cost of the light box, it is determined to install the UV curing device on the top of the oven of the sixth color group of the gravure press, and connect the heat dissipation device to the air duct device of the gravure press. Imported UV lamp tubes are used. The curing width of each lamp tube is 700mm, and the power is 12KW. Each two lamp tubes are used as a group, so the effective curing width can reach 1300mm; In order to meet the curing speed of 120m/min, two groups of lamps (a total of 4 lamps) were finally used; Adopt circulating water cooling. The final configuration of UV curing device is: 1 electric cabinet, 4 fans, 4 light boxes, imported UV tubes, and imported parts for electrical control (Schneider). In terms of control methods, we consider the following two methods

(1) hierarchical control method

start the UV curing device to enter the standby state. At this time, the UV lamp cover is closed, and start the printing press imprint button. When the UV lamp cover is opened, the UV lamp enters the working state I. when the printing speed increases to a certain set value, the UV lamp enters the working state II. When the printing speed decreases, the UV lamp power decreases, and when it decreases to a certain set value, the UV lamp cover closes. The temperature control device is set in the light box. When the air temperature is higher than the set value, the UV light turns off, the fan starts and the power-off delay. The water cooler is equipped with a flow switch and a temperature controller. When the flow is less than the set value or the water temperature exceeds the set value, the UV lamp will turn off automatically. This scheme has low cost and mature technology

(2) stepless control method

after the stepless control method with transformer is adopted, start the UV curing device to enter the standby state, and then the UV lampshade is closed; Start the imprinting button of the printer, and the UV lamp enters the working state when the UV lamp cover is opened. When the printing speed changes, the output power of the UV curing device is changed by adjusting the transformer of the controller to adjust the curing power of the UV lamp. The largest international rubber and plastic exhibition in Asia opened in Guangzhou on May 20-23, 2015, that is, when the printing speed increases, the power of the UV curing device increases; When the printing speed decreases, the UV lamp power decreases. When it reaches a certain set value, the UV lamp cover closes, the fan starts and the power supply is delayed. The lamp box is equipped with a temperature control device, and the UV lamp turns off when the wind temperature is higher than the set value. The water cooler is equipped with a flow switch and a temperature controller. When the flow is less than the set value or the water temperature exceeds the set value, the UV lamp will turn off automatically. The program has a large investment

after analysis and research, it is decided to adopt the stepless control scheme. Although the investment is high, the control technology is advanced and the operation effect is good. After practice, it has been running for more than half a year, and the effect is remarkable, in line with expectations