What Skills Are Needed For Rotary Gravure Printing?

Rotogravure printing is a technology-intensive task that requires a wide range of skills, encompassing equipment operation, process control, quality inspection, maintenance and safety management. Specific skill requirements and analysis are as follows:
1.Equipment operation skills
Cylinder Installation and commissioning
Cylinder Replacement: Replace plate cylinder quickly according to printing specification (e.g. width, color, etc.) to ensure cylinder surface is clean and undamaged.
Pressure Adjustment: control printing pressure by adjusting the gap between the impression cylinder and the plate cylinder to avoid excessive pressure leading to drum wear or insufficient pressure leading to color distortion.
Register control: The phase of each color cylinder is adjusted using a mechanical or electronic register system to ensure accurate alignment of images during multicolor printing (error ≤ 0.1mm).
Ink Supply System Operation
Ink Feed: Master the operation of ink pumping, mixing and circulation systems to ensure even ink supply and avoid precipitation and blistering.
Viscosity Control: Monitor ink viscosity using a viscometer and add solvents or diluents as needed to maintain a stable viscosity (for example, solvent type inks should be maintained at 15-25 seconds per 4 cups). Squeegee Installation: Install the fixture correctly, adjusting the angle (usually 15-25°) and pressure of the fixture to ensure the fixture is clean and does not damage the drum.
Drying System Control
Temperature control: setting the drying temperature according to the type of ink (e.g. solvent type, UV type type) (solvent type is usually 60-80°C, UV type generally requires the use of appropriate power UV lamp).
Airspeed servo control: regulates the volume of hot and cold air to prevent dryness (leading to cracking) or dryness (leading to adhesion).
ii. Process control
Printing Parameter Settings
Line Speed ​​Adjustment: Set the appropriate speed (usually 100-300 m/min) based on substrate material (e.g. BOPP, PET) and ink characteristics.
Squeegee Pressure: the squeegee pressure pressure can be adjusted by pressure gauge or experiential methods to ensure consistent ink layer thickness (e.g., solid area approximately 3-5 microns).
Tension control: Adjust tension during stretching and inversion to prevent substrates from stretching, deforming or wrinkling. Ink Mixing and management
Color Matching: Adjust the color ratio using a color ratio, spectrophotometer, or standard color diagram to achieve dot color printing (e.g., Pantone color matching).
Solvent Mixing: Adjust solvent ratio according to ambient temperature and humidity (such as increasing the proportion of fast drying solvents in summer) to prevent ink from drying too quickly or too slowly.
Ink Circulation: regularly stir ink tank to prevent pigmentation and color variations.
Diagnosis and problem-solving
Common Troubleshooting:
Uneven Ink Color: check scraper, roller surface cleanliness or ink viscosity.
Registration Deviation: Adjust roller phase or check drive gear wear.
Ink Adhesion: Reduce drying temperature or increase wind volume.
Emergency operation: paper breaks, plate jams and other emergency situations, can be quickly shut down for rectification.
III. Quality Inspection Skillss
Online access
Density Testing: Monitor solid density using a densitometer (e.g. solvent ink density should be controlled between 1.4 and 1.8) to ensure consistency of colour. Chromatometric control: ≤ E ≤ 3 is used to measure color difference between printed and standard samples to adjust ink ratio in a timely manner.
Defect Identification: Defects such as knife lines, moles and orange peel can be quickly detected and the cause (such as a foreign object on a scraper or a blocked roller cells) can be identified.
Offline Testing
Adhesion Testing: Test the bond between ink and substrate with a strip (must conform to ISO standards).
Abrasion Resistance Testing: friction tester are used to test the abrasion resistance of printed surfaces (for example, the color of the surface does not change after 50 or more rubs).
Chemical corrosion resistance test: simulation of actual working conditions (such as water resistance, oil resistance, etc.), testing the stability of ink.
IV. INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION Maintenance Skills
Daily maintenance
Roller cleaning: daily with a special cleaning agent clean the drum surface, to prevent ink residue corrosion chromium plating.
Lubricating Components: transmission gears, bearings and other components the regular lubrication to reduce wear.
Electrical inspection: check whether electrical components such as motor and sensor are functioning normally to avoid short circuit or malfunction. Regular maintenance
Moderate maintenance: Once a month or once a year, remove key components (such as doctor blade system systems and dryers) for deep cleaning and adjustment.
Repair: After major equipment malfunction or significant decrease in accuracy, the equipment shall be overhauled by a professional technician or manufacturer technicians to restore the performance of the equipment.
Spare Parts management
Inventory Management: Stock frequently worn parts (such as doctor blades, seals and bearings) to ensure timely replacement.
Lifetime tracking: Record the service life of key components, such as rollers and gears, and plan ahead for replacement.
V. Safety Management Skills
Operational standards
Personal protection: Wear protective glasses and gloves to avoid ink touching your skin or eyes.
Machinery Safety: Lock the main power supply to prevent accidental restarting if the machine fails. Use professional tools when cleaning rollers and avoid hand involvement.
Fire safety: Familiar with the flammability of solvent type ink, maintain work area ventilated, equipped with fire extinguishers.
Emergency Measures: ink leakage: immediately with absorbent material cleaning, to prevent it from entering the drainage system.
Equipment Malfunction: Press the emergency stop button and display a warning sign to prevent accidental operation. Injuries: Know basic first aid methods (such as eye washing and dressing) and contact healthcare provider promptly.
VI. INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION Continuous Learning and adapt
Technology update
Keep up to date with the latest industry technology (e.g. the application of water-based ink in digital gravure printing) and attend training or study materials to update your knowledge.
Mastering the operation of upgraded equipment (e.g., new automatic registration systems and online detection functions).
Environmental Requirements
Learn about VOC emission standards (such as GB38508-2020), optimize ink usage and exhaust gas treatment.
Promote environmentally friendly inks (e.g. water-based and UV) and reduce the use of solvent inks.
Skill Enhancement Suggestions
Practical experience: gain experience by operating different types of machines (e.g., high-speed rotary gravure presses, satellite gravure).
Case study: Analyze typical malfunction cases (such as drum chamber blockage, excessive color variation, etc.) and summarize the solution.
Cross-departmental Collaboration: Communicate with front and backprocessing departments to optimize the entire production process (e.g. reduce release time).