Epson industrial and professional inkjet printers, most notably the Epson ColorWorks CW-C4000 series (CW-C4000E (BK), CW-C4000E (MK), CW-C4030, etc.).
 
Function and Importance
Waste Ink Collection: Its primary function is to absorb and contain the excess or "waste" ink generated by the printer. This waste ink is primarily created during routine operations like:
Printhead Cleaning Cycles: The automatic cleaning process that keeps the printhead nozzles clear and prevents clogs.
Initial Setup/Charging: Ink that is flushed through the system when new cartridges or the printer itself is first set up.
Printer Protection: By safely storing the waste ink, the maintenance box prevents it from leaking into the printer's internal components, which could cause damage or malfunction and prolong the life of the machine.
Print Quality Maintenance: Proper waste ink management ensures that the printer operates cleanly, helping to maintain high-quality, consistent, and smudge-free prints.