Talking about the latest glazing drying technology (2)

Solve the adhesion of solvent-based glazing coating due to temperature and humidity changes.
The use of UV curing technology in China's printing and packaging industry has developed rapidly, mostly used in printing and finishing after printing. In 1994, UV-curable coatings for paper processing increased by 100% compared with 1993. The annual consumption has reached 50 tons. It will increase year after year. In addition to ultraviolet radiation-excited fluorescent powder developed by Peking University as its main raw material, the mainland itself needs to be purchased from Hong Kong, Taiwan, Japan and other places to meet demand.

UV curing light sources generally use high-pressure mercury lamps or metal halide lamps. The output power must be controlled at 80-120W/cm to ensure that the UV coating cure speed is < 0.5s. At the same time there is the problem of the depth of cure, the degree of curing, and the post-curing lag time.

Electron beam (EB) heating drying method

Electron beam drying treatment method is a new type of energy conversion processing method used by foreign developed countries in recent years for the application of electron beam processing technology such as perforation, notching, cutting and other mechanical processing to a multi-color high-efficiency printing process. Electron beam (EB) is a polymerized, dense, directional electron flow generated by an electrical vacuum device. Using the high power density electron beam processing method, the electrons emitted from the hot cathode are controlled by the electrostatic field of the control electrode and the accelerating anode to be condensed into a dense, small-surface-mounted electron beam that moves in the same direction. When the electron beam hits the workpiece, the kinetic energy becomes thermal energy, producing an extremely high temperature that can instantaneously melt or vaporize any material. It is considered by the scientific community as a drying technology with the best processing consistency in the near future. Allows inks and coatings to be maximally crosslinked and polymerized without post cure and solvent residue. At the same time, the use of heat energy is highest.

Most high-speed production line printing operations require that the inks, adhesives, and coatings be dried in the unit. The use of electron beam (EB) alone as a dry treatment method is not economical in terms of price and space utilization.

III. Trends in the United States and Europe

As a carrier for printing and packaging, paper still occupies the dominant position in the world market. But beautiful, durable, lightweight, and highly processable plastics have rapidly increased in the United States and Europe in the markets for food, daily necessities, makeup and hygiene products and other product packaging. At the end of 1995, sales of soft and semi-rigid paper and soft plastics in Europe and the United States reached 66.4 billion U.S. dollars, an increase of 31% over 1990. Since then, paper packaging has grown at an average annual rate of 3.9%. It will increase to 36.4 billion U.S. dollars by the year 2000. The development of soft plastic packaging is faster than paper packaging, with an average annual growth rate of 7.2%. By the year 2000, it will reach US$512. Manufacturers are actively adopting new heat-sensitive plastic materials and their corresponding innovative processing methods that do not cause shrinkage of carrier substrates, replacing traditional processing methods of existing paper products after finishing.