1. Function of the squeegee
The squeegee is a key component of a screen printing machine. During printing, it pushes the ink forward across the screen and evenly spreads it over the mesh, forcing the ink through the open areas onto the substrate. It also helps control ink deposit thickness and print edge definition.
2. Optimal squeegee angle
The angle between the squeegee and the substrate is a critical parameter in screen printing. If the angle is too large, excessive ink is deposited, leading to waste and possible smearing. If the angle is too small, the ink may not pass through the mesh properly, also causing waste and poor print quality.
In most cases, the optimal angle is 45 degrees. At this angle, a single printing pass usually produces satisfactory results. This reduces workload, improves efficiency, and helps avoid registration problems caused by insufficient screen tension.
3. Causes of squeegee not moving during printing
Several factors may cause the squeegee to stop moving or press too heavily against the screen:
Incorrect squeegee angle: An angle that is too large or too small can prevent smooth squeegee movement. The angle should be adjusted to approximately 45 degrees.
High ink viscosity: If the ink is too thick, the squeegee may have difficulty pushing it, resulting in halted movement. Replacing the ink with a lower-viscosity type can solve this problem.
Insufficient operator force: In manual or semi-automatic operations, if the operator does not apply enough force when moving the squeegee, it may fail to travel properly and affect print quality.
Electrical or pneumatic faults: In fully automatic machines, squeegee movement failure may result from electrical or pneumatic issues, such as damaged buttons, PLC faults, faulty solenoid valves or flow control valves, or damaged cylinders. The specific cause should be identified through inspection and repaired accordingly.
For replacement of non-standard squeegee holders, angle adjustment brackets, or related pneumatic components, Hansheng Automation can provide custom machining based on customer drawings or sample parts.
