To produce good thermal paper, from the beginning of the chemical preparation, the choice of the base paper to the final slitting are all essential. This is mainly about the two- component method for producing thermal paper.
Due to the high cost of thermal coating, in order to reduce the production cost, we can minimize the coating amount of the thermosensitive color under the premise of satisfying the user's performance. This will increase the quality requirements for base paper. In the purchase of thermal base paper, the requirements of high smoothness, low air permeability, no needle eye must be met. Second, the wet strength of the base paper should be large, as far as possible without joints.
The most important and usually overlooked problem is lignin. We recommend customers to choose the chemical pulp base paper, not mechanical pulp base paper. This is dependent on the pulping process, Due to the mechanical pulping method, the lignin in the trees is not destroyed, it reacts with the chemical in the thermosensitive coating, causing the color developing to become weak.
Coating machine is the core equipment of the project, the main role is to quickly and evenly coated with a variety of coatings on the base paper. Thermal coating is not capsule type coating, it can be coated by any coating method, such as air knife, doctor knife, scraping bar, roller transfer, curtain and so on.
drying temperature of the thermal paper process is important, the wrong temperature will cause color developing. Generally we adopt the hot air blowing, it is divided into several independent drying area, so that to get a reasonable drying curve to ensure that the paper temperature will not be too high.Although the base paper smoothness requirements is high, but after the coating it would be usually through calender finishing, but the pressure should not be too large, otherwise it will cause color developing.