Negative Ink
Pressure System

Negative Ink
Pressure System

Ink Supply System and the Negative Pressure Control System Upgrade on the JHF UV LED Digital Inkjet Printers - Full Closed-Loop System.

Introduction

The UV LED digital inkjet printing technology has been leading the USA market for high-end digital inkjet printers. Focused on maximizing customer value, JHF has continually improved and upgraded its technology. JHF technical engineers have transformed the core parts to ensure stable quality, optimized the software algorithms, and enhanced image data processing. These improvements have redefined the efficiency and stability of JHF products, enhancing user experience. Here, we introduce the transformation made to the negative pressure and ink supply system on the JHF UV LED digital inkjet printers – full closed loop system.

Core Function of the Negative Pressure System

The negative pressure system is essential in controlling ink flow between the sub ink tank and the print heads. It prevents ink spilling and dropping from the print heads by creating suction in the sub ink tank. A full negative pressure system includes:

  • Sub ink tank
  • Negative pressure pot
  • Negative pressure pump
  • Pressure detecting device
  • Electric control system

Limitations of Open Loop Systems

Most printers on the market use open loop systems, which are susceptible to environmental factors like temperature and atmospheric pressure, causing errors. Open loop systems cannot detect or correct these errors, compromising stability.

Advantages of the Closed Loop System

In response, JHF engineers developed a full closed loop system. This independent system avoids external interruptions and corrects parameter deviations. It maintains steady ink control, improving printing performance.

Benefits of the Closed Loop System

The transformation and upgrade of the negative pressure and ink supply system have three direct benefits:

  1. Extended Lifetime of the Negative Pressure Pump

    • In open loop systems, the pump operates constantly. The closed loop system, however, allows intermittent operation through software control, doubling the pump’s lifespan and reducing operational costs. The new system also reduces pump noise, enabling quieter operation.
  2. Improved Printing Stability

    • The closed loop system stabilizes the ink pressure between the sub ink tank and print heads, preventing ink drops and leaks. This precise control eliminates ink breaks, enhancing the overall stability and performance of JHF UV LED digital inkjet printers.
  3. Automated Control

    • The new system replaces extensive manual adjustments with software control, allowing customers to manage the negative pressure system via a computer workstation. This fully automatic system ensures stable operation under precise software control.

Air Collection Tank and Ink Management

The JHF UV LED digital inkjet printers feature CMYK and White ink collection tanks with the print head carriage.

  • Placement and Function

    • The air collection tank for CMYK and varnish ink is on the left side, while the tank for white ink is on the right side. Both are on the print head carriage.
    • Sensors alert the software if ink enters the air collection tank, triggering a siphon effect that can draw ink into the negative pressure tank and disrupt pressure balance.
  • System Response to Ink in Air Collection Tank

    • The JHF control system will seal the ink path by closing the positive pressure solenoid valve, negative pressure solenoid valve, and ink supply pump. This prevents ink from entering the negative pressure tank and damaging electronic components.

Avoiding Common Issues with Open Loop Systems

Many printers with open loop systems experience ink spillage and electrical damage due to compromised stability. The closed loop system developed by JHF engineers avoids these issues by maintaining steady ink control and promptly correcting any deviations.

Bottom Line

The transformation and upgrade of the negative pressure and ink supply system by JHF demonstrate a commitment to quality and innovation. JHF’s ongoing R&D efforts aim to enhance every detail, reflecting the company’s vision and dedication to excellence in digital inkjet printing technology.