Ricoh TH5241 Printhead — Complete Technical Reference

The Ricoh TH5241 is Ricoh's first thin-film piezoelectric printhead, using silicon MEMS technology developed in collaboration with Xaar and released commercially under the TH series designation. It is commonly called "Gen5i" in the wide-format and UV printing market, though Ricoh does not officially use that name. This reference page covers the TH5241's full specifications, how it differs from the Gen5 (MH5420) and Gen6 (MH5320), what applications it's suited for, and who should and shouldn't buy it.

Full technical specifications

Specifications sourced directly from Ricoh's official TH5241 product page.

TH5241 vs Gen5 MH5420 vs Gen6 MH5320

This is the comparison that matters most for buyers. The TH5241, Gen5 (MH5420), and Gen6 (MH5320) are three separate Ricoh printhead families that are not interchangeable. Each requires its own controller board, waveform, ink path, and cable configuration. The table below covers the key differences.

How the thin-film MEMS design works

The TH5241 uses a thin-film piezoelectric actuator made through MEMS (Micro-Electro-Mechanical Systems) silicon microfabrication. This is a different construction method from the stacked bulk PZT ceramic actuators in the MH-series heads. Ricoh's development of this technology traces to a 2016 collaboration with Xaar on the Xaar 1201 GS2p5 printhead — when Xaar exited the thin-film market, Ricoh reclaimed the design and developed it into the TH5241, addressing the Xaar 1201's known limitations in the process.

What this means practically:

• The actuator is smaller per nozzle, which is how Ricoh fits 4 isolated ink channels into a 52.7 mm wide head body
• The drop formation uses a bend mode actuation — the piezo element bends rather than compresses, producing the small 3 pl base drop size
• There is no integrated heater, because thin-film MEMS actuators work within a tighter viscosity window (7 mPa·s vs 11 mPa·s for Gen5). The ink needs to be matched to the head at ambient temperature
• Many components are resin rather than metal, which keeps weight down to 63 g — about half the weight of an MH-series head

The TH5241 achieves multi-drop greyscale by merging drops in flight before they reach the substrate, not by varying actuator voltage. This allows 4 distinct drop sizes at 24 kHz mode (3, 6, 12, and 21 pl) or 2 drop sizes at 40 kHz mode.

Applications and use cases

Ricoh lists five official application areas for the TH5241:

• Sign graphics — wide-format scanning systems where four colors from one compact head simplifies the carriage
• Label printing — high native resolution (up to 1,200 dpi) for fine text and barcodes on pressure-sensitive labels
• Textile printing — aqueous ink compatibility with 1,280 nozzles at 600 npi covers most fabric printing resolutions
• DTG (direct to garment) — compact head size fits within garment printer carriage constraints; 4-color single head reduces head count
• DTS (direct to shape) — cylindrical and 3D surface printing on bottles, tubes, pens, tumblers, cosmetics packaging, promotional items

The DTS application is the most distinctive. The TH5241's 3 pl minimum drop, compact form, and 4-color single-head design make it particularly well-suited to DTS systems where the head mounts at a fixed position above a rotating mandrel and carriage space is at a premium. The smaller drop size produces finer detail on curved surfaces where dot placement geometry differs from flat-bed work.

Who should buy it — and who shouldn't

Part numbers and the TH5421 typo

The official Ricoh model number is TH5241. You will frequently see it listed as TH5421 on eBay, Chinese supplier sites, and some aggregator marketplaces — this is a digit transposition that has become so common that it appears as an MPN on eBay product listings. Both refer to the same head. If you receive a head and the label says TH5241, it is correct regardless of how it was listed in the order.

Other search terms and references for the same printhead:

• Ricoh Gen5i printhead
• Ricoh G5i head
• TH5241 (correct) / TH5421 (typo)
• J381-0038 (common Chinese distributor part number)
• Ricoh TH series, first generation

The TH5241 is in the TH series, not the MH series. Ricoh's MH-series heads (MH2420, MH5420, MH5320, etc.) use stacked bulk PZT actuators in stainless steel housings. The TH series uses thin-film MEMS silicon. They are different product lines.

Ink and operating requirements

Viscosity and surface tension

Viscosity ceiling is 7 mPa·s — tighter than the Gen5 MH5420 (11 mPa·s). The TH5241 has no integrated heater, only a thermistor for temperature monitoring. This means you cannot warm the ink to reduce viscosity the way you can with MH-series heads. If your UV ink thickens in a cold shop environment, jetting consistency will drop. Keep the print environment above 18–20°C and allow time for both ink and head to reach operating temperature before running production.

Surface tension requirement: 27 ± 5 mN/m. Most UV-curable inks formulated for piezoelectric printheads fall within this range, but confirm with your ink supplier before switching. Solvent-based inks and aqueous inks are both compatible when formulated to spec.

Ink types

UV-curable is the most common in practice for DTS and sign graphics work. Solvent is used in wide-format scanning systems. Aqueous is less common for the TH5241's typical applications but is fully supported. For any new ink, run a jetting test — small drop volumes at 3 pl are sensitive to surface tension variation in a way that larger-drop heads are not.

Operating temperature and environment

The spec sheet lists an operator temperature range of up to 40°C. The more relevant floor is approximately 18°C — below that, UV ink viscosity typically rises beyond the 7 mPa·s ceiling. There is no lower bound specified by Ricoh; practical experience in DTS operations suggests keeping the print environment at 20°C or above for consistent jetting.

Maintenance

Standard printhead maintenance applies: regular nozzle checks, capping when idle, purge cycles after extended downtime. Because the TH5241 lacks an integrated heater, cold-start recovery takes longer than on MH-series heads. Run two purge cycles and a full nozzle check before the first production job of the day.

Related resources

Technical specifications sourced from Ricoh official TH5241 product page. Printhead design history referenced from All Print Heads (2020). Questions? Contact our US-based team before ordering — we confirm compatibility at no charge.