How to Print High-Gloss Silicone Smoothly in the Printing Process
Accurate operating parameters are the key to avoiding defects such as pinholes, bubbles and streaks, and directly affect the high-gloss texture of the final product.
Selection and Angle of Squeegee
Squeegee Hardness: Select polyurethane squeegees with a hardness of 70–80 Shore A. This moderate hardness ensures full transfer of silicone while minimizing squeegee marks.
Squeegee Angle: Control it within the range of 45°–60°. An angle that is too small will cause silicone accumulation, while an angle that is too large will result in insufficient printing pressure and uneven thickness of the silicone layer.
Printing Pressure and Speed
Pressure: Follow the standard of "silicone fully covers the substrate surface without missing prints or accumulation". Excessive pressure will squeeze out excess silicone and cause burrs; insufficient pressure will lead to incomplete coverage.
Speed: Maintain a uniform printing speed, controlled at 0.5–1 m/s. Printing too fast tends to trap air bubbles, while printing too slow will make the silicone stay on the screen for an extended period and cause partial drying.
Coordination Between Ink Returning and Squeegeeing
The ink return blade must coordinate with the squeegee to ensure that the screen is evenly covered with silicone after each printing stroke, avoiding local silicone shortage. The ink returning pressure should be slightly lower than the squeegeeing pressure to prevent damage to the screen emulsion layer.
Defoaming Treatment
Air can be easily mixed into silicone during stirring and printing, forming surface bubbles that impair the high-gloss effect:
After Stirring: Let the silicone stand for 10–15 minutes for natural defoaming, or use a vacuum defoaming machine for degassing (0.08 MPa, 5–8 minutes).
After Printing: Gently blow the silicone surface with a hot air gun (temperature < 40℃) to eliminate tiny surface bubbles before proceeding to the curing process.
