Filter

The filter is a key component in the printer’s ink supply system. It intercepts impurities and air bubbles, protects the printhead, stabilizes ink supply, and improves final print quality. Common types include disc (butterfly), inline (column), and capsule filters, each designed for different levels of precision and flow rates. Filters can significantly extend the lifespan of printheads and ink pumps. They are indispensable in eco-solvent printers, UV flatbed printers, coding machines, and textile direct-to-garment (DTG/DTF) printers.

Core Functions of Filters

Filtering Impurities to Protect the Printhead
During production, transportation, and storage, ink may contain fine particles or sediment. Filters intercept these impurities, preventing them from entering the nozzles (only tens of microns in diameter) and avoiding clogging, misfiring, or nozzle failure.

Stabilizing Ink Flow
Ink transported through pipelines may carry micro-particles or deposits that disrupt smooth flow. Filters ensure stable and continuous ink supply, resulting in uniform and uninterrupted printing output.

Removing Air Bubbles for Stable Jetting
Ink circulation or agitation can easily generate air bubbles. Once bubbles enter the printhead, they may cause missing jets or unstable firing. Some capsule/degas filters can effectively remove bubbles, maintaining clear and stable ink lines.

Extending Equipment Lifespan
Long-term use of unfiltered ink accelerates wear on ink pumps, pipelines, and printheads. Filters reduce system wear, lower maintenance frequency, and extend the lifespan of printheads and the ink delivery system.

Improving Print Quality
Filters ensure that the ink entering the printhead is pure and uniform. This leads to more stable colors, sharper details, and prevents banding or nozzle dropouts caused by impurities.

Types of Filters

Disc Filter (Butterfly Filter)

Structure: Flat shape with inlet and outlet ports at both ends, usually containing a membrane or mesh filter medium inside.
Function: Mainly removes particles and impurities to prevent nozzle clogging. Compact and easy to install, widely used in printers such as eco-solvent and UV machines.
Applications: Ideal for small-format printers requiring high ink cleanliness, such as UV and eco-solvent printers.

Inline Filter (Column Filter)

Structure: Cylindrical shape with straight-through inlet and outlet ports on the top and bottom. The filter element is relatively long, providing a larger filtration area and lower pressure loss. It can be made from different materials such as PP, nylon, or stainless steel mesh.
Function: Withstands higher pressure, provides greater precision than disc filters, and supports continuous use with larger flow rates.
Applications: Common in industrial-grade printers, UV flatbeds, and large-format printers, typically installed in the main ink supply line or beneath the sub-tank.

Capsule Filter

Structure: Single-use sealed capsule design with microporous membranes (such as polypropylene or PTFE). Filtration precision can be as fine as 0.2 μm.
Function: Effectively removes ultra-fine particles and bubbles, ensuring ink purity. Most are disposable and not washable.
Applications: Used in printers with the highest ink purity requirements, including high-end UV printers, coding machines, and specialized devices in semiconductor or biomedical printing.

Application Fields

Eco-solvent printers: Filter ink impurities to prevent nozzle clogging and ensure stable long-term output.
UV flatbed/roll-to-roll printers: White ink tends to settle; filters reduce clogging and uneven jetting while acting as secondary purification in circulation systems.
Industrial coding machines: These demand extreme ink stability; filters remove micron-level impurities and bubbles, ensuring jetting precision.
Textile DTG/DTF printers: Remove flocs and sediment in textile inks, protecting printheads and ensuring uninterrupted mass production.

Usage and Maintenance Recommendations

Replace filters every 3–6 months depending on usage frequency and ink type.
If pressure fluctuations or frequent nozzle dropouts occur, check whether the filter is clogged.
For high-precision equipment, use filters that are heat-resistant, corrosion-resistant, and well-matched to the system.
Ensure correct ink flow direction during installation; incorrect installation may lead to improper filtration or unstable ink supply.

Contact Us

Filters are often overlooked but are among the most critical components in printing systems. Choosing the correct specifications and replacing them on time ensures stable system operation and reduces printhead maintenance costs. For further questions about filters, feel free to contact us.