Screen Printing Glass ink is a specialized functional coating designed for printing on glass surfaces with a strong adherence. This screen printing glass ink bonds effectively to the glass substrate through methods such as high-temperature sintering or low-temperature curing. Based on the processing temperature, these inks fall into three categories: high-temperature glass inks (720-850°C), tempered glass inks (680-720°C), and low-temperature glass inks (100-150°C). High-temperature and tempered glass inks are particularly popular in applications like architectural curtain walls and automotive glass, thanks to their outstanding weather resistance. Conversely, low-temperature glass inks are recognized for their quick curing and high solvent resistance. Ink-mixing solvents for these applications are divided into oil-based and water-based categories, with water-based glass inks increasingly replacing traditional oil-based options due to their lack of odor and compliance with EU environmental standards.
This ink formulation boasts strong adhesion, resistance to acids and alkalis, excellent weather durability, and high color stability. The screen printing process involves multiple stages, including substrate preparation, ink blending, screen printing, and sintering. In response to growing environmental concerns, the industry is developing lead-free environmentally friendly glass ink to mitigate pollution risks by reducing lead content in toners. Some formulations have achieved impressive acid resistance of up to 72 hours per ASTM standards. In the automotive sector, glass inks also provide protective properties for conductive silver paste and UV shielding, making them essential for printing components like windshields and sunroofs.
The inks can be classified based on processing temperature as follows:
- High-temperature glass inks: Also referred to as high-temperature tempered glass inks, these inks sinter at temperatures ranging from 720-850°C, ensuring a robust fusion to the glass surface. They are extensively utilized in architectural curtain walls, automotive glass, and various home appliance applications.
- Tempered glass inks: These inks undergo a rapid baking process at 680-720°C, followed by cooling to achieve excellent color adhesion and durability. The outcome is a vibrant hue and a strong, resilient glass structure that offers exceptional resistance to atmospheric corrosion.
- Glass decal inks: With sintering temperatures between 500°C and 700°C, these inks are prevalent in industries like glass, ceramics, and sports equipment.
- Low-temperature glass inks: These inks are baked at 100-150°C for about 15 minutes, ensuring superior adhesion and solvent resistance. Ordinary glass ink dries naturally, with a surface drying time of roughly 30 minutes and a total drying time of around 18 hours, making them suitable for printing on various glass types and polyester self-adhesive paper.
In terms of environmental standards, glass inks can be categorized as follows:
- Lead-containing glass ink: These inks include metals such as chromium, nickel, and lead, which present certain pollution risks.
- Lead-free environmentally friendly glass ink: The use of toners with minimal lead content significantly reduces pollution risks, hence these formulations are often labeled as environmentally friendly glass inks.
