Infrared drying of printing machines is a technology that uses the thermal effect of infrared rays to accelerate the drying of ink on printed matter. It has the advantages of fast drying speed, good drying effect, and little impact on ink and substrate.
1. Working principle:
– Infrared ray is a kind of electromagnetic wave, which is outside the visible light range and has a longer wavelength than red light and has a significant thermal effect. When infrared rays are irradiated onto the surface of a printed matter, the moisture, solvents and components in the ink in the printed matter will absorb the energy of the infrared rays, causing their own temperature to rise rapidly.
– When the temperature rises, water and solvents will evaporate faster, and the components in the ink will also undergo chemical reactions or physical changes faster, thereby achieving rapid drying of the ink. This drying method starts heating from the inside of the object and acts on the inside and outside at the same time. Compared with traditional hot air drying and other methods, the drying efficiency is higher and the effect is better.
2. Composition of infrared drying device:
– Infrared lamp: It is the core component that generates infrared rays. According to different wavelength ranges, it can be divided into short-wave infrared lamps, medium-wave infrared lamps and long-wave infrared lamps. Infrared rays of different wavelengths have different drying effects on different inks and substrates. For example, short-wave infrared rays have the characteristics of fast heating and strong penetrating ability, and are suitable for occasions that require high drying speed; long-wave infrared rays have better thermal properties. Uniformity, suitable for occasions with high requirements on drying uniformity.
– Reflector: usually installed around the infrared lamp, used to reflect infrared rays and improve the utilization of infrared rays. The shape and material of the reflector will affect the reflection effect. It is generally made of metal and is mostly parabolic or elliptical in shape. It can concentrate the light emitted by the infrared lamp onto the surface of the printed matter.
– Air ducts and fans: Air ducts are used to guide airflow, and fans are used to generate airflow. During the drying process, the fan sucks the outside air into the air duct, filters it and blows it to the surface of the printed matter, taking away the evaporated water and solvent, thus accelerating the drying process. At the same time, the airflow can also play a role in cooling the infrared lamp tube and printed matter to prevent the temperature from being too high.
– Temperature control system: including temperature sensor and controller. The temperature sensor is installed inside the drying device or on the surface of the printed matter to monitor temperature changes in real time and transmit the temperature signal to the controller. The controller automatically adjusts the power of the infrared lamp or the speed of the fan according to the set temperature value to maintain the stability of the drying temperature.
– Box and bracket: used to install and fix the above components to ensure the stability and reliability of the drying device. The box is usually made of thermal insulation materials, which can reduce heat loss and improve energy utilization.
3. Advantages:
– Fast drying speed: The energy of infrared rays can be quickly absorbed by the printed matter, causing the moisture and solvent in the ink to quickly evaporate, greatly shortening the drying time and improving printing production efficiency.
– Good drying effect: Infrared drying starts heating from the inside of the object, which can make the ink dry evenly, avoiding the situation where the surface is dry but the inside is not dry, thus ensuring the quality of the printed matter.
– Little impact on ink and substrate: Compared with hot air drying and other methods, the temperature of infrared drying is relatively low, and strong wind will not cause blowing or deformation of the ink and substrate. It is especially suitable for drying conditions. Higher-end printed matter, such as high-end books, picture albums, etc.
– Energy saving and environmental protection: The infrared drying device has a high energy utilization rate and can achieve drying effects in a short period of time, reducing energy consumption. At the same time, since there is no need to use a large amount of hot air during the drying process, thermal pollution to the environment is also reduced.
4. Application scenarios:
– Offset printing: In offset printing, infrared drying technology can be used for online drying of printed matter, that is, drying is performed simultaneously during the printing process to improve production efficiency. For example, on a high-speed offset printing press, an infrared drying device can be installed after the printing unit to quickly dry the printed matter for subsequent printing or processing.
– Gravure printing: Gravure printing uses a larger amount of ink and requires a longer drying time. Infrared drying technology can effectively accelerate the drying of ink and improve the production efficiency and quality of gravure printing.
– Flexo printing: The ink used in flexo printing is usually water-based ink, which dries slowly. Infrared drying technology can help water-based ink dry quickly, solve the problem of slow drying speed in flexo printing, and improve the adaptability and production efficiency of flexo printing.
