Controlling the thickness of screen printing silicone deposit is a key step to ensure printing quality. Here are some effective ways to control the thickness of screen printing silicone deposit:
1. Choose the right silicone and screen
Silicone selection:
Choose silicone with appropriate viscosity and fluidity according to printing needs.
Silicone with higher viscosity may form a thicker deposit layer when printing, while silicone with lower viscosity may form a thinner deposit layer.
Screen selection:
Choose a screen type that is suitable for the printing pattern and ink characteristics, such as polyester mesh, nylon mesh or stainless steel mesh.
The mesh count (mesh density) of the screen will also affect the ink penetration and deposit thickness. The higher the mesh count, the less ink penetration and the thinner the deposit layer; the lower the mesh count, the more ink penetration and the thicker the deposi layer.
2. Adjust printing process parameters
Squeegee hardness and pressure:
Choose the appropriate squeegee hardness to ensure that the ink can be scraped evenly across the screen during printing.
Adjust the pressure between the squeegee and the screen to control the ink penetration and deposit thickness. Excessive pressure will result in an overly thick ink layer, while too little pressure may result in a thin or uneven ink layer.
Scraper speed:
Control the speed of the scraper to affect the fluidity and deposit of the ink. A faster scraper speed may result in a thinner ink layer, while a slower scraper speed may form a thicker ink layer.
Printing angle:
Adjust the angle between the squeegee and the screen to optimize the ink penetration and deposit effect. Generally, the angle should be controlled within the range of 45°~60°.
3. Optimize the surface state of the substrate
Cleaning the substrate:
Before printing, ensure that the surface of the substrate is clean, free of oil and impurities to ensure that the ink can adhere evenly.
Adjust the humidity of the substrate:
Control the humidity of the substrate to avoid affecting the adhesion and deposit of the ink due to excessive or low humidity.
4. Use auxiliary tools and techniques
Viscometer:
Use a viscometer to measure the viscosity of the silica gel to ensure that it meets the printing requirements. By adjusting the viscosity of the silica gel, the thickness of the deposit layer can be indirectly controlled.
Printing additives:
Add an appropriate amount of printing additives (such as diluents, thickeners, etc.) to adjust the fluidity and viscosity of the silica gel, thereby controlling the thickness of the deposition layer.
Thickness measurement tools: Use thickness measurement tools (such as thickness gauges) to monitor and measure the thickness of the deposit layer to ensure that it meets the design requirements.
5. Precautions
Uniform stirring: Stir the silicone thoroughly before printing to ensure its uniformity and stability. This helps to avoid uneven ink deposition during the printing process.
Control ambient temperature and humidity: Maintain appropriate ambient temperature and humidity during the printing process to avoid affecting the adhesion and deposit of ink due to environmental changes.
Regularly maintain equipment: Regularly maintain and service the printing equipment to ensure its normal operation and accuracy. This helps to reduce the problem of uneven ink deposit caused by equipment failure.
In summary, the thickness of screen printing silicone deposit can be effectively controlled by selecting suitable silicone and screen, adjusting printing process parameters, optimizing the surface state of the substrate, using auxiliary tools and techniques, and paying attention to relevant matters.