Ricoh printhead Knowledge
YILIJET
Ricoh industrial inkjet printheads are Laminated Piezo Push Mode (d33) drop-on-demand (DOD) piezo printheads. No ink heating required (some models integrate built-in heaters for high-viscosity inks). Core construction: Stainless steel chamber + isolated laminated PZT piezo. The piezo actuator is separated from ink path for superior corrosion resistance and long service life. Ricoh proprietary Bi-pitch laminated piezo technology suppresses nozzle crosstalk and delivers consistent droplet ejectionRicoh.
Main product families:
- MH Series (G5/G5i/G6, MH5420/MH5422 etc.): Stainless steel metal printheads, widely adopted in UV flatbed printers. Supports grayscale variable droplet. New MH versions come with native ink recirculation, compatible with white ink and varnish. Applied in signage, flatbed UV and packaging printingRicoh.
- TH Series (TH6310F): MEMS thin-film piezo with built-in ink recirculation. Supports large print gap up to 4 mm. Designed for high-speed OnePass production for textile, corrugated and label applications. 600 dpi, max firing frequency up to 80 kHz理光(Ri....
- GH Series (GH2220): Cost-effective silicon-based printhead, mainly used for textile DTG and small-format signage.
Key features: ✅ Advantages: Corrosion-resistant stainless steel structure; piezo isolated from ink channel for longer life; Bi-pitch design reduces nozzle crosstalk; multi-drop grayscale capability; some models with heater for high-viscosity ink; new versions equipped with ink recirculation to reduce sedimentation and clogging; compatible with UV, water-based, eco-solvent, white ink. ❌ Limitations: Relatively high printhead cost; waveform development is complex. Older non-recirculation models demand strict maintenance for white ink.
Ricoh MH series adopts Laminated Piezo Push Mode (d33):
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The laminated piezo ceramic sits outside the ink chamber. The piezo actuator is physically isolated from ink and does not contact ink.
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When drive voltage is applied, the laminated piezo ceramic extends axially, pushing the diaphragm to compress the ink chamber. Pressure rises rapidly inside the chamber to eject ink droplets out of nozzle.
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When voltage is removed, piezo ceramic contracts and resets. Negative pressure forms inside ink chamber to refill ink.
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Multi-pulse waveform control enables grayscale variable droplet, one nozzle can produce multiple droplet sizes.
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Recirculation version: Ink continuously circulates behind pressure chambers to carry pigment sediment and air bubbles away, greatly reducing clogging risk for heavy pigment inks such as white ink.
| 参数 |
021 MH5320 |
022 MH5420 |
023 MH5421F |
024 MH5421MF |
025 MH5440 |
026 MH5441 |
027 MH5420F |
028 MH5420MF |
029 TH5241 |
030 MH2810 |
| Brand |
Ricoh |
Ricoh |
Ricoh |
Ricoh |
Ricoh |
Ricoh |
Ricoh |
Ricoh |
Ricoh |
Ricoh |
| Architecture |
Piston Pusher |
Piston Pusher |
Piston Pusher |
Piston Pusher |
Piston Pusher |
Piston Pusher |
Piston |
Piston |
Piezo |
Piezo |
| Actuator |
Metallic diaphragm |
Metallic diaphragm |
Metallic diaphragm |
Metallic diaphragm |
Metallic diaphragm |
Metallic diaphragm |
Metallic diaphragm |
Metallic diaphragm |
N/D |
N/D |
| Nozzles |
1,280 class |
1,280 |
1,280 |
1,280 |
1,280 |
1,280 |
N/D |
N/D |
N/D |
N/D |
| Rows |
4 × 320 |
4 × 320 |
4 × 320 |
4 × 320 |
4 × 320 |
4 × 320 |
N/D |
N/D |
N/D |
N/D |
| Width |
~54.1 mm |
54.1 mm |
54.1 mm |
54.1 mm |
54.1 mm |
54.1 mm |
N/D |
N/D |
N/D |
N/D |
| Nozzle Pitch |
0.1693 mm |
0.1693 mm |
0.1693 mm |
0.1693 mm |
N/D |
N/D |
N/D |
N/D |
N/D |
N/D |
| Drop |
7–35 pL |
7–35 pL |
7/14/21 pL |
7/14/21 pL |
N/D |
N/D |
N/D |
N/D |
N/D |
N/D |
| Frequency |
~30 kHz |
~30 kHz |
30 kHz |
30 kHz |
N/D |
N/D |
N/D |
N/D |
N/D |
N/D |
| Heater |
Yes/variant |
Yes |
Yes |
Yes |
Yes |
Yes |
N/D |
N/D |
N/D |
N/D |
| Circulation |
Variant |
Yes |
Yes |
Yes/variant |
N/D |
N/D |
N/D |
N/D |
N/D |
N/D |
| Typical Viscosity |
N/D |
N/D |
11 mPa·s |
6 mPa·s |
N/D |
N/D |
N/D |
N/D |
N/D |
N/D |
| Ink |
UV / solvent / aqueous variants |
Industrial |
Aqueous |
Aqueous |
Industrial |
Aqueous |
N/D |
N/D |
Industrial |
Industrial |
| One Pass |
★★★★ |
★★★★ |
★★★★ |
★★★★ |
★★★★ |
★★★★ |
★★★ |
★★★ |
★★★★ |
★★★ |
| White Ink |
★★★★ |
★★★★ |
★★★★ |
★★★★ |
★★★★ |
★★★★ |
★★★★ |
★★★★ |
★★★★ |
★★★ |
| High Viscosity |
★★★★ |
★★★★ |
★★★★ |
★★★ |
★★★★ |
★★★★ |
★★★ |
★★★ |
★★★★ |
★★★ |
| Functional Fluid |
★★★★ |
★★★★ |
★★★★ |
★★★ |
★★★★ |
★★★★ |
★★★ |
★★★ |
★★★★ |
★★★ |
| GTF Glue |
★★★ |
★★★ |
★★★★ |
★★★ |
★★★ |
★★★ |
★★★ |
★★★ |
★★★ |
★★★ |
| Main Advantage |
Versatility |
Industrial maturity |
Heater + circulation |
Lower viscosity |
Multi-color |
Multi-color |
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— |
Industrial |
Industrial |
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Ricoh 的 MH5421 官方资料确认其结构为 piston pusher with metallic diaphragm plate，
1280 nozzles、4×320 staggered、54.1 mm、30 kHz、7/14/21 pL，并带 integrated heater + thermistor；
公开资料给出的 viscosity range 为 11 mPa·s。 |
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| Ricoh 的工程定位 |
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| Ricoh 不应该简单归类为“高粘度喷头”。 |
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| 更准确的是： |
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| Industrial general-purpose printhead + heater + fluid compatibility + robust actuator |
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