High-speed filling of ink cartridges
Precise, bubble-free dispensing of low-viscosity media within 0.25 seconds
Ink cartridges for fountain pens are manufactured in high-volume writing instrument production lines with large output quantities. A critical process step is filling the cartridge with low-viscosity ink. A dosing volume of 1.25 ml must be introduced precisely and bubble-free within only 0.25 seconds.
Filling takes place from bottom to top to prevent air inclusions and ensure uniform filling. In automated production lines, multiple cartridges are filled in parallel. The combination of very low viscosity and extremely short dosing time places high demands on dosing technology.
What challenges arise when filling low-viscosity inks?
The low viscosity of 1–1.2 mPas requires highly controlled fluid handling. At the same time, the dosing process must achieve a volumetric tolerance of ±0.025 ml (±2%) within 0.25 seconds.
Key challenges include:
- highly dynamic dosing cycles
- high repeatability at tight volumetric tolerances
- bubblefree bottom-up filling
- controlled reverse rotation for anti-drip performance
- integration into parallel high-volume production lines
Fine pigments in the ink can also create abrasive conditions, requiring wear-resistant component design for long term operation.
How is high-speed ink dosing technically implemented?
The system uses the high performance mzr-11508X1 micro annular gear pump. It enables precise dosing cycles within 0.25 seconds while maintaining tight volumetric accuracy of ±2%.
Precisely controlled reverse rotation ensures clean shut-off and prevents dripping. This anti-drip control is particularly important when dosing low-viscosity liquids to maintain stable and contamination-free production conditions.
The robust material design supports reliable handling of pigment-loaded inks over extended operating periods. Driven by a DC servo motor, the micro annular gear pump delivers high dynamic performance and is designed for continuous operation in high-volume manufacturing environments.
What benefits does this provide for serial production?
By integrating the high-performance pump, equipment manufacturers can:
- achieve ultra-short dosing cycles in high-speed filling processes
- maintain tight volumetric tolerances
- ensure bubble-free dosing of low-viscosity inks
- prevent dripping through controlled reverse rotation
- operate parallel filling systems reliably
- produce large volumes with consistent quality
The micro annular gear pump therefore represents a high-performance solution for precise low-viscosity ink dosing in high-volume ink cartridge manufacturing.