Understanding UV Printing: The Importance of Coatings

Understanding UV Printing: The Importance of Coatings

While UV printers can print directly on many surfaces, some materials like smooth metals, glass, or low-activity silicon can pose a challenge. In these cases, UV coatings are an essential pretreatment step. They significantly enhance the bond between the ink and the material, ensuring the printed design is durable and long-lasting.

Six Common UV Coatings and Their Applications

The market offers six main types of UV coatings, each designed for specific materials and with unique application methods:

Glass Coating: Used for materials like plexiglass, tempered glass, glazed tiles, and crystal. It comes in a fast-drying or a bake-on version. The fast-drying one needs about 10 minutes to set after wiping, while the bake-on version requires oven heating before it can be used.

PC Coating: Suitable for hard PC materials, which typically have poor natural adhesion. Note that not all PC materials need this coating.

Metal Coating: For metals such as aluminum, copper, tinplate, and aluminum alloy. It must be applied to the finished metal product; using it before the forming process will significantly reduce its effectiveness.

Leather Coating: Used on genuine leather, artificial leather, PVC leather, and PU leather. Simply spray it onto the surface and let it air dry before printing.

ABS Coating: Versatile and works well on wood, PVC, ABS, plasterboard, and acrylic. After wiping on the coating, let it air dry before printing.

Silicone Coating: Specifically for low-surface-activity materials like silicone and rubber. The surface must first be pre-treated with a flame to activate it. Apply the coating in a thin layer to ensure it cures properly.

Usage and Storage: Ensuring Quality and Safety

To achieve the best results and ensure safety, follow these key guidelines for using and storing UV coatings:

Usage Notes:

Correct Ratio: If the coating requires a diluent or curing agent, strictly follow the instructions for the correct ratio and mix it thoroughly.

Compatibility Test: Always test the coating and UV ink on a small sample first to check for any adverse reactions like dissolving or bubbling.

Safety Precautions: UV coatings often have a strong odor. Always wear a mask and gloves, and ensure the work area is well-ventilated.

Dedicated Use: Each coating is designed for a specific material; do not mix them or use one coating for all materials.

Storage Guide:

Environment: Store in a cool, dark, and well-ventilated area.

Sealing: Immediately tighten the cap after each use to prevent solvent evaporation.

Pressure: Do not stack heavy objects on top of the container.

Placement: Keep containers on a stable shelf, not directly on the floor.

Common UV Coatings & Applications