Preventing silicone ink from drying on the screen during screen printing is crucial for maintaining smooth printing and avoiding blockages in the mesh. Silicone ink dries quickly due to its chemical properties, but you can use the following techniques to keep it workable:
1. Use a Flood Stroke
After every print, flood the screen by pulling a thin layer of ink across the stencil with the squeegee.
This keeps the ink active and prevents it from drying in the open areas of the stencil.
2. Work in a Cool, Humid Environment
Silicone ink dries faster in warm, dry conditions. Print in a controlled environment with:
Cool temperatures (18–22°C or 65–72°F).
Higher humidity (50–65%) to slow down ink drying.
Avoid placing the screen close to heat sources, such as flash dryers or curing units.
3. Use Retarders or Thinners
Many silicone ink manufacturers provide retarders or ink additives that slow the curing process.
Add a small amount (as recommended by the manufacturer) to the ink mixture. This extends the pot life and keeps the ink fluid during printing.
4. Minimize Ink Exposure
Keep the ink container closed when not in use to prevent it from curing due to air exposure.
Load small amounts of ink onto the screen at a time to avoid excess drying.
Cover unused parts of the stencil with masking tape or plastic sheets to reduce airflow contact.
5. Keep the Screen Moving
Avoid leaving the screen idle for long periods. If printing is paused:
Perform a few flood strokes to keep the ink spread evenly.
Use a spray bottle with silicone-compatible cleaning solution to lightly mist the screen and keep the ink moist (do not overdo it).
6. Clean the Screen Regularly
Wipe the screen periodically during printing to remove dried ink buildup.
Use a silicone-compatible screen cleaner or solvent to clean the screen thoroughly between printing sessions.
7. Use a Low-Mesh Count Screen
Silicone ink is thicker than many other inks, so use a low-mesh count screen (80-120 mesh).
This reduces the chance of ink drying in finer mesh openings.
8. Avoid Extended Flash Curing Near the Screen
Flash curing stations can emit heat that accelerates drying. Ensure the screen is not directly exposed to the curing heat.
By using these techniques, you can effectively prevent silicone ink from drying on the screen, ensuring a smoother and more efficient printing process.