“GELART JET printhead” - a next-generation inkjet printhead that discharges large droplets of high-viscosity ink and ink containing large-diameter particles
Background
Responding to demands for a sustainable society, we are developing inkjet technology that will lower the burden on the environment and reduce materials loss through the digitization of analog manufacturing processes. To enable the use of inkjet technology in various manufacturing sites, it is necessary to have inkjet printheads that are capable of printing or coating with inks that have a wide range of characteristics.
Solutions
We developed the GELART JET printhead with completely new inkjet printhead technology that makes it possible to discharge high-viscosity ink and ink containing large-diameter particles over long distances. This makes it possible to perform vehicle coating on the uneven and curved surfaces of car bodies, to perform digital painting on three-dimensional and large areas such as walls and roads, and to use an inkjet for the high-productivity manufacture of products such as secondary batteries. This realizes a reduction of the masking work and materials loss that previously occurred in coating and production processes and makes it possible to reduce energy consumption.
Example applications of the GELART JET printhead
Vehicle coating
Digital painting on three-dimensional objects and large areas
Secondary battery manufacturing
Technical highlights
By incorporating technologies such as the following, we have realized inkjet printheads that can be used in a variety of applications that were not previously possible, including in applications used for thick coating and coating on large areas, uneven surfaces and curved surfaces.
- Actuator displacement expansion technology that enables printing on large areas and thick coating
By equipping the printhead with a mechanism that increases the displacement of the piezo, we made it possible to discharge highly viscous ink in large droplets and realized printing and coating with high productivity. - Sealing technology that prevents the leakage of inks that contain large-diameter particles
We optimized the material and shape of the valve at the tip of the needle to enable the sealing of ink that contains large-diameter particles. - Joining technology that realizes printing on uneven and curved surfaces
By using technology for the joining of metal materials without adhesives with high accuracy, we improved the pressure resistance of the printhead and made it possible to accurately discharge the ink over long distances.
GELART JET printhead structure and discharge mechanism
The ink is discharged by constantly applying pressure to the ink and using the movement of the piezo to control the opening and closing of the valve at the tip of the needle at high speed
GELART JET printhead appearance
Targeting characteristics of the GELART JET printhead and specifications of existing printheads
| GELART JET printhead Targeting characteristics | [Reference] Representative values for existing Ricoh printheads RICOH MH5422/5442 |
|
|---|---|---|
| Method | Laminated piezo (d33) valve system | Laminated piezoelectric (d33) push mode system |
| Maximum driving frequency | Approx. 2 kHz or less | 50 kHz (2 levels), 30 kHz (4 levels) |
| Fluid pressure | Approx. 0.5 MPa | Slight negative pressure |
| Number of nozzles | 8, staggered (4 × 2 rows) | 1,280, staggered (320 × 4 rows) |
| Nozzle pitch | Approx. 5 mm | Approx. 0.1693 mm |
| External dimensions | Approx. 123 (W) × 22 (D) × 172 (H) | Approx. 89 (W) × 24.5 (D) × 66 (H) |
| Viscosity | < Several 100 mPa⋅s (cP) | 10 to 12 mPa⋅s (cP) |
| Droplet volume | < Several 100 nl (Several 100,000 pl) | < 21 pl |
| Particle size supported | < 100 µm | — |
| Flight distance | < 100 mm (Curved surfaces supported) | < 3 mm (Flat surfaces only) |
Ricoh's vision
Ricoh is utilizing three key technologies—inkjet printhead technology, ink supply technology, and printing system technology—that the company has cultivated over many years with the aim of applying and expanding these technologies to create new value with a “digital transformation in manufacturing” that changes the conventional wisdom. The new jetting system technology using the "GELART JET printhead" next-generation inkjet printhead goes beyond the scale limits of conventional inkjet technology and can also print and apply various materials, so it contributes to a sustainable society by lowering environmental pollution, reducing waste, saving energy, and improving the quality of life.
Functional jetting