1. Fujifilm Dimatix Technical Advantages: Renowned for high-precision inkjet technology, the printhead offers extremely fine droplet control (minimum 1.5 pL), making it suitable for high-resolution printing applications, including industrial UV inkjet and electronics printing. Application Scenarios: High-end packaging, label printing, and functional material coatings. 2. Ricoh Technical Characteristics: Known for high throughput and operational stability, the printheads support multi-gray level printing and are ideal for high-speed production environments. However, droplet size is slightly larger than Dimatix, resulting in slightly lower precision. Market Positioning: Business printing, advertising graphics, and other mid-to-high-end markets. 3. EPSON Core Advantages: Mature micro-piezo technology, long printhead lifespan, and accurate color reproduction. The printhead has lower nozzle density, making it suitable for small to medium-format printing. Typical Applications: Photo-quality printing, fine art reproduction. 4. Brother Features: High printhead integration with low maintenance costs. However, technology updates are slower. Mainly used in office and light industrial applications. 5. Kyocera Differentiation: Ceramic printheads with strong corrosion resistance, compatible with high-viscosity inks, and capable of hundreds of millions of injections. Known as “printhead aristocracy” due to high cost. Applicable Fields: UV flatbed printing, industrial signage. 6. Xerox Technical Highlights: Unique wax-based printing technology, excellent color saturation, but equipment is complex with high maintenance costs. 7. Océ (now Canon) Features: Leading high-speed roll-fed inkjet technology, ideal for large-volume document printing. Printheads are highly customized. 8. Xaar Advantages: Variable droplet technology (VSDT) offers flexibility for wide-format graphics. Modular printhead design simplifies maintenance. 9. TTEC (Toshiba Tec) Innovation: Compact piezoelectric printhead design, e.g.,

The flow characteristics of piezoelectric Drop-on-Demand (DOD) inks are a core factor affecting print quality, with viscosity behavior and flow control being particularly critical. The following is a comprehensive analysis based on technical principles and industry practices: I. Viscosity Characteristics and Flow Control 1. Viscosity Units and Measurement Viscosity is typically expressed in millipascal-seconds (mPa·s) or Poise (P), and directly affects the flow behavior of ink through the printhead. High viscosity may lead to nozzle starvation (insufficient ink supply) Low viscosity can cause ink spreading or misting (satellite droplets) 2. Dynamic Viscosity Regulation Piezoelectric DOD systems control droplet ejection by applying electrical pulses to deform the piezoelectric crystal, enabling precise ink flow control. Commercial printheads typically require a specific viscosity range (e.g., 10–20 mPa·s) Binders are designed with optimized molecular structures to balance fluidity and film formation performance II. Impact of Viscosity on the Printing Process Viscosity plays a critical role in determining: Droplet formation stability Jetting consistency Print resolution and edge sharpness Improper viscosity leads to unstable jetting behavior and degraded print quality. III. Key Process Challenges and Solutions 1. Nozzle Starvation and Air Entrapment Problem: At high firing frequencies, insufficient ink replenishment may allow air to enter the nozzle, disrupting droplet stability. Solution: Use thixotropic inks (shear-thinning behavior): Lower viscosity during jetting to improve flow Recover viscosity at rest to prevent dripping 2. Nozzle Wetting and Ink Backflow Problem: Reverse ink flow (creep) inside the nozzle may cause: Missing jets Ink misting Solution: Use surface tension modifiers (e.g.,

Analysis of Inkjet Technology Types and Ink Design Characteristics   Ink Performance Comparison Across Inkjet Technologies Ink Property CIJ (Single Point) CIJ (Multi Deflection) DOD Piezo Valve Jet Desktop Piezo Desktop Thermal Inkjet Raw Material Complexity High (up to 10) High (up to 15) High (up to 10) Low (~4) Medium (~6) Medium (~4) Functional Application Medium High High Medium Medium Low Purity (filtered particles, μm) High (<0.5) Medium (<3.0) Medium (<1.0) Low (<5.0) Medium (<1.0) High (<0.2) Reliability (jetting cycles) High (>10¹⁰) High (>10¹¹) High (>10¹⁰) Medium (>10⁸) High (>10⁹) High (>10⁹) 1. Raw Material Complexity Continuous Inkjet (CIJ) – Single Dot: Ink requires high electrical conductivity (primarily solvent-based) Contains volatile solvents (e.g., ketones) Raw materials must be strictly filtered to prevent nozzle clogging Continuous Inkjet (CIJ) – Multi-Deflection: Ink must be compatible with electrostatic deflection (e.g., UV-curable inks) Requires low surface tension (32–36 mN/m) to ensure precise droplet deflection Drop-on-Demand (DOD): Piezoelectric inkjet (e.g., office piezo printers): Requires higher viscosity ink (10–20 cP) Thermal inkjet (e.g., office thermal printers): Requires water-based ink (3–5 cP) to match bubble generation dynamics Valve Jetting: Ink requires high solid content (≥95%) Suitable for UV or solvent-based systems Requires nano-level dispersion (D50 ≤ 200 nm) to improve adhesion 2. Functional Applications CIJ Single Dot: Used for industrial coding and marking (e.g., inkjet coders) Relies on high-speed jetting (up to 80 kHz) Limited grayscale capability CIJ Multi-Deflection: High-precision label printing Enables multi-line printing via electrostatic control Requires complex driving circuitry DOD Piezoelectric Inkjet: High-resolution

I. Core Cause Analysis (1) Underlying Logic of Ripples Caused by Abnormal Ink Viscosity 1. Issues with Low-Viscosity Ink When the ink viscosity falls below the standard range, intermolecular cohesion becomes insufficient, leading to “tailing” and “ink bleeding diffusion” after ejection: During printhead movement, low-viscosity ink cannot stabilize quickly. As adjacent droplets merge, irregular ripple patterns resembling water waves are formed. At the same time, low viscosity increases the number of satellite droplets (＞3 per 1,000 drops). These tiny droplets randomly attach to the color block surface, further intensifying the ripple effect. Main causes of low viscosity include: Temperature increase (viscosity decreases by ~0.25 cP per 1°C rise) Excess solvent Overuse of surfactants 2. Issues with High-Viscosity Ink When viscosity exceeds the standard range, ink fluidity decreases, and the piezoelectric actuator must provide greater driving force: Uneven droplet velocity (CV ＞ 8%) leads to inaccurate landing positions, forming “accumulation ripples.” High viscosity prolongs the decay time of nozzle pressure oscillation. In multi-pulse printing, residual vibrations from the previous waveform overlap with subsequent pulses, causing droplet deviation (phase deviation ＞ 5°) and resulting in periodic ripples. Main causes of high viscosity include: Excess pigment concentration (volume fraction φ ＞ 0.2) Overuse of thickeners Pigment flocculation due to long-term storage 3. Impact of Poor Viscosity Stability Environmental fluctuations (e.g., RH ＞ 70% causing moisture absorption in water-based inks) or failure in temperature control of the ink circulation system lead to real-time viscosity variations (＞ ±1 cP). This dynamic instability prevents the printhead

1. Ink Performance Testing Framework 1.1 Basic Physicochemical Property Evaluation Density Measurement: 0.8–1.5 g/cm³ with temperature compensation of ±0.0005 g/cm³/°C. Viscosity Control: 3–50 mPa·s with thixotropic index of 0.5–2.0. Surface Tension Optimization: 30–50 mN/m to ensure stable droplet formation. 1.2 Functional Verification Color Fastness Testing: Water, sunlight, and abrasion fastness ≥ Grade 4 (ISO 105-B02). Environmental Compliance: Zero detection of APEO, heavy metals, and aldehydes; VOC content ≤5%. Conductive Inks: Must pass a 10⁻³ Gy radiation dose test with resistance change rate <0.1% per year. 2. Drive Waveform Optimization Methods 2.1 Parameter Tuning Procedure Initial Setup: Establish baseline using manufacturer-recommended pulse (e.g., 26 V / 2.18 μs). Dynamic Adjustment: Monitor droplet velocity (5–6 m/s) and satellite droplet occurrence. Multi-Pulse Optimization: Employ 40 V/μs rise time to control droplet separation precision. 2.2 Intelligent Calibration Technology Adjust the waveform system to match ink properties and printhead resonance frequency. Real-Time Feedback: Correct pulse timing using high-speed imaging at 10,000 fps. 3. Printhead Performance Evaluation 3.1 Durability Testing Accelerated Aging: Print 5000 pages of 85% coverage patterns while monitoring nozzle clog rate. Environmental Testing: Validate corrosion resistance of gold-plated contacts under 85°C / 85% RH conditions. 3.2 Jetting Quality Assessment Atomization Uniformity: Coefficient of variation (CV) ≤15% (GB/T 20790-2006). Response Time: ≤300 ms for fire-safety applications (ISO 15822). 4. Ink–Printhead Collaborative System 4.1 Compatibility Verification Particle Size Control: Nano-silver ink D50 <50 nm to ensure printhead compatibility. Conductivity Management: Water-based ink <4000 μS/cm to prevent electrode corrosion. 4.2 Closed-Loop Control System Integrates pressure and

The droplet observation instrument is a precision device used to analyze the dynamic characteristics of ink droplets during inkjet printing. It is widely applied in industrial printing, electronic circuit printing, and bioprinting. The following summarizes its core functions and technical features: 1. Core Functions 1.1 Dynamic Parameter Measurement Capable of real-time capture of droplet velocity (accuracy ±0.5%), volume (resolution 0.1 pL), and flight angle (detection accuracy ±0.5°), supporting single or dual droplet synchronous analysis. Uses high-speed imaging (up to 80,000 frames per second) to record droplet trajectories, identifying satellite droplets, tailing, and other anomalies. 1.2 Print Quality Verification Integrates the printhead module with a motion system to enable verification printing, allowing actual print testing while observing the droplets. 2. Technical Features Feature Description High-Speed Imaging Integrates multispectral illumination with high-speed cameras (e.g., 1000 fps zoom microscopy systems), adaptable to inks of different refractive indices. Automated Analysis Built-in algorithms automatically calculate droplet parameters (e.g., ejection stability, tail length) and generate quantitative reports. Multi-Angle Observation Some systems use dual cameras for synchronous shooting, improving the comprehensiveness of parameter measurement. 3. Typical Applications Industrial Printing: Evaluates droplet flight stability before UV ink curing, optimizing printhead parameters. Electronic Circuits: Ensures precise positioning of conductive silver ink droplets (e.g., for OLED printing equipment). Bioprinting: Monitors the morphology of cell-laden microdroplets, ensuring biocompatibility. 4. Technical Principle Analysis 4.1 Core Observation System Optical Imaging Module: Utilizes a high-speed CCD camera (frame rate ≥100,000 fps) combined with multispectral LED illumination, capturing droplet trajectories via synchronized triggering technology. Motion

I. Core Testing Logic: The Design Essence and Targeted Nature of Text Areas (1) Test Sample Design of Text Areas 1. Typeface and Size Design The test samples include two core types of fonts, based on ISO 12647-2 printing standards and digital inkjet industry specifications: Standard typefaces: Select serif and sans-serif fonts (e.g., Song typeface and Heiti), covering font sizes from 6pt to 72pt (common office and printing sizes). Include: Standard characters (e.g., “中, A, 1”) Fine-stroke characters (e.g., “十, 一, 丨”) Complex characters (e.g., “繁, 馨, 器”) → to comprehensively verify clarity across different stroke structures. Reverse (knockout) text: Includes: White text on black background (high ink coverage background + knockout text) Black text on white background (no ink background + high ink coverage text) → same sizes as standard text, specifically used to magnify defects such as jagged edges and ink bleeding. Reverse text is more sensitive to ink diffusion and edge control. Layout requirement: Same font size and type per row, with spacing ≥ 5 mm to avoid interference between adjacent characters. 2. Functional Differences Compared with Other Detail Tests Test Module Core Validation Target Testing Logic Application Scenario Text Area Text clarity (edge sharpness, no merging/breaking) Visual + magnified inspection Documents, packaging labels, advertising text Siemens Star / Radial Lines Resolution & directional consistency Line width threshold analysis General detail performance Photo Resolution Area Image texture detail Scene-based evaluation Imaging, art reproduction Core conclusion: The text area is a highly targeted detail test module, focusing on

Classification of Inkjet Printing Technologies Inkjet printing technology is mainly divided into two major categories: Continuous Inkjet (CIJ) Drop-on-Demand (DOD) Among them, Drop-on-Demand (DOD) is further subdivided into: Thermal Inkjet Piezoelectric Inkjet The following analysis focuses on the droplet formation stage and practical importance, along with their advantages and disadvantages. 1. Continuous Inkjet (CIJ) Continuous Inkjet (CIJ) Continuous droplet generation, switched for printing Binary: Kodak, Domino, VideoJet Multi-level deflection: Domino, Imaje, Hitachi, Linx, VideoJet Droplet Formation Stage: Ink is continuously ejected from the nozzle under high pressure to form a continuous ink stream. This stream is broken into uniform droplets by piezoelectric crystal vibration. The droplets are electrically charged via a charging electrode, and their landing positions are controlled by deflection plates. Unused droplets are collected and recirculated. Importance: High-speed jetting (industrial speeds up to 100 m/s) makes it suitable for production lines such as packaging and label printing. Advantages and Disadvantages: Advantages: High printing speed, suitable for mass production Ink recycling system reduces waste Disadvantages: Complex structure, high maintenance cost Requires conductive ink, limiting ink type selection 2. Drop-on-Demand (DOD) Drop-on-Demand (DOD) Droplets are generated only when needed Thermal inkjet: Canon, HP, Kodak, Lexmark, Funai, Memjet, Olivetti Piezoelectric inkjet: Brother, Epson, Fujifilm Dimatix, HP, Konica Minolta, Kyocera, Oce, Panasonic, Ricoh, SII, TTEC, Trident, Xaar, Xerox Micro-voltage: Seiko Epson, Tonejet 2.1 Thermal Inkjet Droplet Formation Stage: A heating element rapidly vaporizes the ink to form a bubble. The expansion of the bubble ejects the ink droplet, and after cooling, the

I. Mapping Between Motion System Error Sources and Printing Defects 1. Open-Loop Control Defects Backlash and Belt Stretching: In open-loop systems, the lack of position feedback allows elastic deformation of transmission components to cause printhead positioning errors (typically 0.1–0.5 mm displacement), resulting in dot overlap or gap banding. For example, belt stretching may cause the media feed distance to deviate by ±3% from the theoretical value, directly affecting multi-color registration accuracy. Solution: Adopting closed-loop servo control (e.g., permanent magnet synchronous motor vector control) can improve positioning accuracy to ±0.01 mm. 2. Encoder Resolution Limitations Low-resolution encoders (e.g., 500 lines/rev) introduce angular displacement detection errors, resulting in ±1 pulse equivalent rounding errors. In high-precision printing applications (e.g., 1200 dpi), a single positioning error can reach ±25 μm, leading to periodic fluctuations in droplet placement. Improvement Direction: Using a 23-bit absolute encoder can increase the theoretical resolution to 0.0003°. 3. Dynamic Motion Disturbances Speed Fluctuation: Transport speed variations of ±5% can lead to flight time errors (e.g., droplet landing deviation up to 50 μm at 8 m/min). Mechanical Noise: Vibration frequencies above 100 Hz may cause slight printhead oscillations (amplitude approx. 3–10 μm), resulting in random ink misting. Control Strategy: Three-loop control (current–speed–position) can reduce speed fluctuation to below 0.1%. II. Key Influencing Factors of the Media Handling System 1. Media Feed Error Stepper motor step loss or transmission backlash can cause deviations in media movement distance (typically ±0.2 mm), resulting in 0.1–0.3 mm color band misalignment during bidirectional printing. Case Study:

I. Core Causes of Color Bleeding Phenomena 1. Uncontrolled Capillary Action When the surface tension of the ink (typically 25–35 mN/m) is lower than the capillary pressure of the paper (approximately 40–60 mN/m), pigment particles migrate laterally along the fiber network. This results in a 0.1–0.3 mm color mixing band between adjacent color blocks. In yellow–black overprinting areas, this effect can reduce black density by 15–20%, forming a noticeable “bleeding halo.” 2. Dynamic Pigment Sedimentation During multi-color overprinting, if the first jetted ink contains 0.5–1.2% anionic dispersant, it may neutralize the cationic components (such as quaternary ammonium salts) in subsequent inks. This leads to pigment flocculation. Tests show that this phenomenon can reduce the spreading area of cyan ink on yellow ink by 37%. II. Key Factors Affecting Edge Roughness Parameter Ideal Range Degradation Threshold Improvement Measures Ink viscosity 10–15 cP (25°C) <8 cP or >20 cP Add 2–3% polyvinylpyrrolidone Surface tension 28–32 mN/m <25 mN/m Introduce 0.1% silicone additives Paper absorption speed 1–3 seconds >5 seconds Pre-coat with nano-alumina layer Pigment particle size 150–300 nm >500 nm Grind to D90 < 200 nm III. Advanced Control Technologies 1. Chemical Anchoring Strategy Add 0.3% vinylphosphonic acid to cyan ink to form coordination bonds with cellulose fibers in the paper, reducing pigment fixation time from 1.8 seconds to 0.4 seconds. Use amphoteric surfactants (such as cocamidopropyl betaine) to reduce the lateral penetration depth of black ink to 28 μm. 2. Timing Optimization of Inkjetting Adopt a “fast-drying + slow-drying” combination strategy: