Screen clogging is a common problem in screen printing, especially when printing high-viscosity materials (such as screen printing silicone). The following are detailed methods to solve the problem of screen clogging, which are summarized as follows:
1. Optimize screen parameters
Choose appropriate mesh and mesh material
High mesh: Use a 150-300 mesh screen to ensure that the silicone can pass evenly and reduce the risk of clogging.
Chemical corrosion-resistant material: Choose polyester or stainless steel mesh to avoid silicone corrosion on the screen.
Adjust screen tension
Appropriately increase tension: Keep the screen tension at 20-30N/cm to ensure that the screen is flat and reduce the residue of silicone on the screen.
2. Improve printing process
Control scraper pressure and angle
Appropriately increase pressure: Ensure that the silicone fully fills the screen, but avoid excessive pressure that causes the screen to deform.
Adjust scraper angle: It is usually recommended that the scraper angle be 60°-75° to ensure that the silicone passes evenly through the screen.
Optimize printing speed
Control printing speed: Avoid printing speed that is too fast or too slow to ensure that the silicone has enough time to pass through the screen.
Use diluent
Add diluent: Add an appropriate amount of diluent to the silicone to reduce the viscosity of the silicone and reduce clogging.
3. Strengthen screen cleaning and maintenance
Clean the screen regularly
Cleaning in time: After printing is completed, clean the screen with a special cleaning agent immediately to prevent the silicone from curing and clogging the mesh.
Thorough cleaning: Use an ultrasonic cleaner or a high-pressure water gun to ensure that the screen is thoroughly cleaned.
Store the screen
Dry storage: Place the cleaned screen in a dry, dust-free environment to prevent dust and impurities from clogging the mesh again.
4. Improve the silicone formula
Adjust the viscosity of the silicone
Reduce the viscosity: Reduce the viscosity of the silicone by adding a diluent or adjusting the silicone formula to make it easier to pass through the screen.
Control the curing time of the silicone
Extend the open time: Choose a silicone with a longer curing time to ensure that the silicone does not cure prematurely during the printing process.
5. Use auxiliary equipment
Install an electrostatic eliminator
Eliminate static electricity: Static electricity will absorb dust and impurities, causing the screen to clog. Installing an electrostatic eliminator can effectively reduce static electricity.
Use screen dryer
Quick drying: Use screen dryer immediately after printing to speed up the drying of silica gel and reduce residue.
6. Other suggestions
Check the screen regularly
Check the mesh: Check the screen regularly for blockage or damage, and repair or replace it in time.
Train operators
Standardized operation: Ensure that operators are familiar with the correct printing process and screen maintenance methods to reduce blockage caused by human factors.