Painted glass, also known as back-painted glass or baked-on glass, is a type of decorative glass where the back of the glass is coated. The main principle of the process is to spray or coat a specific coating onto the back of the glass, then heat it or allow it to cure naturally, allowing the coating to adhere firmly to the glass surface.
The main process includes two steps: coating and curing. Coating can be applied to the back of the glass through spraying, roller coating, screen printing, or dip coating. The standard curing process involves placing the coated glass in an oven at 30-45 degrees Celsius for 8-12 hours to ensure complete curing and strong adhesion. Some processing points use natural air drying to save costs or time, but this method results in weaker paint adhesion and makes the glass prone to peeling in humid environments.
Depending on the coatings and processes used, painted glass is mainly divided into two categories: spray-painted glass and colored enamel glass. Painted glass boasts vibrant colors, often in monochrome or partial multi-color combinations, offering excellent initial decorative effects. However, when used outdoors, it is prone to peeling and flaking after exposure to wind, sun, and rain. Colored enamel glass, further divided into low-temperature and high-temperature enamel glass, offers better resistance to outdoor environments and avoids peeling issues. However, low-temperature enamel glass may experience scratches and color fading due to adhesion problems.
Since traditional paints may be harmful to human health, modern painted glass production must prioritize environmental protection and health safety. Raw materials and coatings meeting environmental standards should be selected during manufacturing to comply with relevant health and safety regulations and market demands.
To ensure the quality and durability of painted glass, its coating must meet a series of performance requirements. Common testing items include coating adhesion, abrasion resistance, weather resistance (UV resistance, aging resistance), chemical resistance, water resistance, and color consistency. These tests are conducted according to relevant national standards (such as GB/T) or international standards (such as ISO, ASTM).
