Inkjet Recording Head Nozzle Clogging Prevention via Surface Tension Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet recording methods face challenges with ink discharge stability due to nozzle clogging and ink deviation caused by the degradation of repellent films on nozzle plates, especially when there is a large difference between dynamic and static surface tensions of the ink.
Innovation Solution
Applying drive pulses to a pressure generating device in an inkjet recording method, where the dynamic surface tension of the ink is 10 mN/m or more greater than the static surface tension, and using a voltage changing portion of the drive pulses with a time duration of one third or more of the resonance period of the liquid chamber to stabilize ink discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a repellent film is formed on the nozzle plate surface to prevent ink contamination, then ink discharge stability is improved, but the film peels off over time causing nozzle clogging and image quality degradation
Solution Approach 1:
The patent removes the repellent film component entirely and replaces it with ink formulation control (surface tension management) and precise pressure control mechanisms. This extracts the problematic peeling issue while maintaining ink discharge stability through alternative means.
Solution Approach 2:
The patent changes the surface tension parameters of the ink (controlling the difference between dynamic and static surface tension to 3-10 mN/m) and adjusts pressure application timing to prevent ink adhesion to the nozzle plate, eliminating the need for a repellent film while maintaining discharge stability.
2Ease of operation
If the dynamic surface tension of ink is reduced to improve ink flow, then ink dischargeability is improved, but ink strongly adheres to the nozzle plate surface causing displacement and streaks
Solution Approach 1:
The patent precisely controls the surface tension parameters by managing the difference between dynamic and static surface tension (3-10 mN/m range) and adjusts pressure application timing, achieving both good dischargeability and preventing harmful adhesion to the nozzle plate.
Solution Approach 2:
The patent applies pressure periodically with specific timing (applying pressure during the flight phase of ink droplets and releasing it during the return phase) to maintain proper meniscus formation and prevent ink adhesion, enabling continuous stable discharge without strong adhesion issues.
3Manufacturing precision
If pressure is applied to discharge ink droplets from fine nozzles, then high resolution imaging is achieved, but meniscus collapse and ink overflow occur
Solution Approach 1:
The patent applies pressure periodically in synchronization with the ink droplet discharge cycle, applying pressure during the flight phase and releasing it during the return phase. This periodic pressure control maintains meniscus stability while enabling high-resolution droplet discharge from fine nozzles.
Solution Approach 2:
The patent applies pressure in advance during the flight phase of ink droplets before the meniscus needs to return to its initial state, ensuring proper droplet formation and discharge while preventing meniscus collapse and overflow.
4Manufacturing precision
If ink is discharged with low static surface tension to improve wetting properties, then image quality is improved, but ink displacement and streaks occur at sites where repellent film is degraded
Solution Approach 1:
The patent controls the surface tension parameters (dynamic surface tension 10-20 mN/m, static surface tension 30-40 mN/m, difference 3-10 mN/m) to achieve proper wetting and image quality while preventing harmful adhesion and displacement issues, even without a repellent film.
Solution Approach 2:
The patent removes the repellent film dependency and achieves reliable discharge stability through ink formulation control and pressure timing, allowing low static surface tension ink to be used without causing displacement or streaks.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach prevents ink deviation and nozzle clogging by ensuring stable ink discharge even when the repellent film is degraded, maintaining high image quality by effectively managing the surface tension differences and meniscus formation.
Implementation Method 1
a pressure generating device to generate a pressure in the liquid chamber and discharging droplets of ink from the nozzle
Implementation Method 2
In normal state (stationary condition), the meniscus forms a bridge on the side of a liquid chamber with a nozzle edge as a reference point
Implementation Method 3
The ink has a dynamic surface tension 10 mN/m or more greater than the static surface tension of the ink when the surface life length is 15 ms and 3 mN/m or more greater than the static surface tension of the ink when the surface life length is 1,500 ms
Data Source
AI summary
An inkjet recording method includes applying one or more drive pulses to a pressure generating device of a recording head including a nozzle plate, a liquid chamber, and discharging droplets of ink from the nozzle. Also, the following conditions 1 and 2 are satisfied.1. The ink has a dynamic surface tension 10 mN/m or more greater than the static surface tension of the ink when the surface life length is 15 ms and 3 mN/m or more greater than the static surface tension of the ink when the surface life length is 1,500 ms, as measured by maximum bubble pressure technique at 25 degrees C.2. At least one of the drive pulses has a voltage changing portion to draw in the ink, the voltage changing portion having a changing time of one third or more of the resonance period of the liquid chamber.