Introduction to Pad Printing Machines

Operation of Pad Printing Machine

Method of applying ink to the etched plate (steel plate)

There are various ways to apply ink to the etched plate.First, ink is applied onto the etched plate, and then a retractable doctor blade scrapes off the excess ink. At this point, the solvent in the ink remaining in the etched areas volatilizes to form a colloidal surface. After that, the silicone pad descends onto the etched plate to pick up the ink.

Ink pickup and printing

The silicone pad absorbs most of the ink from the etched plate and then lifts up. During this process, part of the ink layer volatilizes, and the remaining surface layer helps achieve better adhesion between the printed product and the silicone pad. The shape of the silicone pad should enable a rolling action to expel excess air between the etched plate and the ink surface.

Application and Development of Pad Printing Machines

According to pad printing machine manufacturers, the ideal scenario during production is that all ink on the etched plate is completely transferred to the substrate. During the transfer process (where ink with a thickness of approximately 10 microns or 0.01 mm is deposited and transferred onto the substrate), pad printing is easily affected by air, temperature, static electricity and other factors.Successful printing is achieved when the evaporation rate and dissolution rate are kept in a balanced state throughout the entire process — from the etched plate to the silicone pad and finally to the substrate. If evaporation is too fast, the ink will dry before being picked up. If evaporation is too slow, the ink surface will not form a gel layer, making it difficult for the silicone pad to transfer ink properly onto the substrate.Pad printing machines were introduced to China in the 1980s. They excel at printing on small, uneven or curved surfaces, offering distinct advantages that compensate for the limitations of screen printing. As a result, this technology has developed rapidly in China in recent years.With China’s further reform and opening-up, a large number of foreign-funded enterprises mainly engaged in electronics, plastics, gifts, toys and other traditional industries have entered the Chinese market. Decoration methods based on pad printing and screen printing have experienced extraordinary growth. According to incomplete statistics, the application rates of pad printing and screen printing in the aforementioned industries have reached 27%, 64%, 51% and 66% respectively.Pad printing machine manufacturers note that paper printing is usually regarded as the mainstream printing industry and receives extensive attention in academic circles. In recent years, digital online printing has gained prominence mainly due to its advantages on paper substrates. For example, screen printing achieves superior results for special inks such as coral ink, ice flower ink and wrinkle ink compared with offset printing and flexographic printing.Overall, the technical threshold of pad printing is relatively low. When production costs rise in developed countries, it becomes difficult for such industries to sustain growth. Therefore, it is an inevitable trend for printing technologies to shift to developing countries with lower labor costs. Except for a few foreign enterprises capable of producing highly automated equipment, most manufacturers have moved their production bases to China.