Fluidity is the reciprocal of ink viscosity. The greater the viscosity, the lower the fluidity, and the lower the viscosity, the higher the fluidity. The fluidity is also related to the plasticity and thixotropy of the ink. The ink with high plasticity and thixotropy has low fluidity, and vice versa. The fluidity of screen printing ink is generally 30~50mm.
The fluidity is high, and the ink spreads after printing, which makes the size of the graphic and text larger, and the fluidity is low, which makes printing difficult, and the graphic and text after printing are short of ink and the lines are incomplete.
The fluidity of ink can be regarded as the degree of natural flow of a certain amount of ink on a certain flat surface within a certain period of time without external force. The fluidity of the ink can measure the thickness of the ink. In screen printing ink, its fluidity is generally controlled at 30 ~ 50mm. The measurement method is to take 1mL of ink and measure its diameter after 15 minutes under a pressure of 2.5kN.
The fluidity of the ink is high, and the imprint is easy to expand, making the thin lines with small gaps unclear or merged; the fluidity is small, the lines in the imprint are easy to break and lack ink, and printing is also difficult.
