During the thermal transfer printing process, the thermal transfer overprinter ribbon frequently contacts and rubs with the printing medium and the print head. If the friction resistance is insufficient, it is easy to cause the thermal transfer overprinter ribbon coating to wear, the pattern to be blurred, or even the thermal transfer overprinter ribbon to break. Therefore, improving the friction resistance of the thermal transfer overprinter ribbon and developing high-performance wear-resistant coatings have become the key to ensuring printing quality and the service life of the thermal transfer overprinter ribbon.
First of all, optimizing the basic material of the thermal transfer overprinter ribbon is the foundation for improving friction resistance. Traditional thermal transfer overprinter ribbon base films mostly use polyester films. In order to enhance their wear resistance, materials with higher hardness and toughness, such as polyimide films, can be selected. Polyimide films not only have high mechanical strength, but also have good high temperature resistance and chemical corrosion resistance, and can effectively resist physical and chemical damage during friction. At the same time, the surface of the base film is pre-treated, such as using plasma treatment, corona treatment and other technologies to improve the roughness and hydrophilicity of the base film surface, enhance the adhesion between the wear-resistant coating and the base film, and prevent the coating from falling off during friction.
Secondly, it is crucial to rationally design the composition and structure of the wear-resistant coating. In the selection of coating materials, nano-scale wear-resistant fillers such as nano-silicon dioxide and nano-aluminum oxide can be introduced. These nanoparticles can be evenly dispersed in the coating, fill the microscopic pores on the surface of the coating, form a dense protective layer, and reduce the surface friction coefficient. At the same time, materials with self-lubricating properties, such as molybdenum disulfide and polytetrafluoroethylene powder, are added. During the friction process, these materials will form a lubricating film on the surface of the coating, reduce the friction between the contact object, and thus reduce wear. In addition, a multi-layer composite structure is used to design the wear-resistant coating, such as the bottom layer to enhance the bonding force with the base film, the middle layer to provide the main wear resistance, and the surface layer to increase lubricity. Through the synergistic effect of each layer, the overall wear resistance effect is improved.
Furthermore, improving the coating preparation process has a significant effect on improving wear resistance. Traditional coating processes have certain limitations in coating uniformity and thickness control. Advanced micro-gravure coating, slit coating and other technologies can be used to accurately control the coating thickness, ensure uniform coating, and avoid local wear caused by uneven thickness. In the coating curing process, ultraviolet curing (UV curing) or electron beam curing technology is used. Compared with the traditional thermal curing method, the coating can be cured quickly in a short time, forming a denser cross-linked structure, and improving the hardness and wear resistance of the coating. At the same time, the process parameters in the coating process, such as coating speed, temperature, pressure, etc., are optimized to find the best process conditions and further improve the coating quality.
In addition, the performance of the wear-resistant coating is further enhanced by surface modification technology. The surface of the wear-resistant coating is treated with chemical vapor deposition (CVD) to form an ultra-thin hard protective film on the surface of the coating to improve the surface hardness and wear resistance. Physical vapor deposition (PVD) technology, such as magnetron sputtering, is used to coat a layer of wear-resistant metal or metal oxide film, such as titanium nitride and zirconium oxide film, on the surface of the coating to give the coating excellent wear resistance and corrosion resistance. Laser surface treatment technology can also be used to cause phase change and remelting of the coating surface through the high energy density of the laser to form a more wear-resistant microstructure.
In practical applications, the use and maintenance of thermal transfer overprinter ribbon will also affect its friction resistance. Reasonably control the printing speed and pressure to avoid a sharp increase in friction between the thermal transfer overprinter ribbon and the printing medium and print head due to excessive speed and pressure. Clean the print head and printing equipment regularly to prevent dust, impurities, etc. from entering the printing system and aggravating the wear of the thermal transfer overprinter ribbon. At the same time, according to different printing needs and environments, select the appropriate type and specification of thermal transfer overprinter ribbon to ensure that the thermal transfer overprinter ribbon works under suitable conditions and prolong its service life.
Finally, it is indispensable to establish a scientific wear resistance detection and evaluation system. A friction and wear tester is used to simulate the friction conditions in the actual printing process, and the wear resistance of the thermal transfer overprinter ribbon is quantitatively tested by setting different friction speeds, pressures, friction times and other parameters. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and other microscopic detection methods are used to observe the surface morphology and microstructural changes of the wear-resistant coating before and after friction, and analyze the wear mechanism. Combined with the actual printing effect, such as the clarity of the printed pattern, the change in color density, etc., the friction resistance of the thermal transfer overprinter ribbon is comprehensively evaluated to provide data support for the research and development and improvement of the wear-resistant coating.
Through the above comprehensive measures from material selection, coating design, process improvement, surface modification to use maintenance and performance testing, the friction resistance of the thermal transfer overprinter ribbon can be effectively improved, and a high-performance wear-resistant coating can be developed to meet the growing printing needs and promote the development of thermal transfer printing technology.
