Maintenance Instructions for Flexographic Printing Machines

As a crucial device in the modern printing industry, flexographic printing machines are widely used in the printing production of various packaging and label products. The stability and reliability of its performance are directly related to printing quality, production efficiency, and the economic benefits of enterprises. To ensure that the flexographic printing machine remains in good operating condition for a long time, extend the service life of the equipment, and reduce the incidence of failures, it is essential to implement correct and regular maintenance measures. The following will detail the key points and methods of maintaining flexographic printing machines.

I. Daily Cleaning and Maintenance
(I) Cleaning the Machine Body and Exterior
After the completion of the daily printing operation, use a clean soft cloth or dust-free paper dipped in an appropriate amount of mild cleaner to wipe the surface of the printing machine body to remove dust, oil stains, and ink stains. Special attention should be paid to the cleaning of the control panel, operation buttons, display screen, and other parts to avoid dust accumulation affecting the operation sensitivity and display clarity.
Regularly clean the working area around the printing machine to keep the environment tidy and prevent debris from entering the machine interior and causing damage to the transmission components and electrical circuits.

(II) Cleaning the Printing Cylinders and Plate Cylinders
Immediately after replacing the printing plate or completing a printing task, clean the printing cylinders and plate cylinders. Use a special solvent and a soft brush to carefully remove the ink remaining on the surface of the cylinders and plate cylinders to avoid the ink drying and becoming difficult to clean, which may affect the subsequent printing quality and the service life of the cylinders and plate cylinders.
Inspect the surface of the cylinders and plate cylinders for scratches, wear, or other damage signs. If any abnormality is found, repair or replace them in a timely manner to ensure the uniformity of the printing pressure and the accuracy of the graphic transfer.

(III) Cleaning the Ink System
Clean the ink fountain, ink pump, ink pipes, and other ink delivery components to prevent the ink from drying and clogging the pipes and nozzles. Remove the remaining ink from the ink fountain and rinse the ink fountain with the corresponding solvent to ensure that there is no residual ink.
For the inkjet system, regularly perform the nozzle cleaning procedure. Use a special nozzle cleaning solution according to the equipment manufacturer's recommendations to keep the nozzles unobstructed and maintain the inkjet accuracy, avoiding nozzle clogging that may lead to problems such as color missing and broken lines in the printed pattern.

II. Maintenance of Mechanical Components
(I) Maintenance of the Transmission System
Regularly check the tension of the transmission belt to ensure that the belt does not slip or become loose during operation. If signs of wear, aging, or breakage are found in the belt, replace it in a timely manner to ensure the stable and reliable power transmission.
Lubricate the gearbox, sprocket, and other transmission components. Add an appropriate amount of lubricating oil or grease according to the equipment requirements. Regularly check the quality and quantity of the lubricating oil. If the quality of the lubricating oil deteriorates or the quantity is insufficient, replace or supplement it in a timely manner to prevent excessive wear of the transmission components due to poor lubrication, resulting in abnormal noise or even damage.

(II) Maintenance of the Impression System
Check the surface flatness and hardness of the impression cylinder. Grind or replace it if necessary to ensure the uniformity and stability of the printing pressure. Regularly clean the rubber blanket or liner on the surface of the impression cylinder to remove dirt and impurities to prevent them from affecting the transfer of the printing pressure and the clarity of the graphic.
Adjust the pressure of the impression system to meet the printing process requirements. During the adjustment process, use a pressure testing tool for accurate measurement to avoid excessive or insufficient pressure causing damage to the printing plate, cylinder, and substrate, while ensuring the consistency of the printing quality.

III. Maintenance of the Electrical System
(I) Inspection of Electrical Circuits
Regularly check the electrical circuits of the printing machine to see if there are any wire breaks, aging, short circuits, or open circuits. Pay special attention to the inspection of the circuits connecting key components such as motors, controllers, and sensors to ensure that their connections are firm and the insulation is good. If any circuit problems are found, repair or replace them in a time manner to prevent electrical failures from causing equipment shutdown, fire, and other safety accidents.
Clean the dust and debris in the electrical control cabinet to maintain a good heat dissipation environment and avoid the shortening of the service life or the occurrence of failures of electrical components due to dust accumulation and poor heat dissipation.

(II) Maintenance of Electrical Components
Regularly inspect and maintain electrical components such as motors, drivers, and sensors. Check the running status of the motor, including temperature, noise, vibration, and other indicators. If any abnormality is found, stop the machine for maintenance in a timely manner to prevent the motor from burning out.
Calibrate the sensitivity and accuracy of the sensors to ensure that they can accurately detect the operating parameters of the printing machine, such as printing pressure, register accuracy, and ink viscosity, and feed them back to the control system for adjustment in a timely manner to ensure the stability and accuracy of the printing process.

IV. Regular Calibration of Precision
(I) Calibration of Register Accuracy
According to the operating procedures of the printing machine, regularly use the register test plate for register accuracy detection and calibration. Adjust the position, tension, and printing pressure of the plate cylinder to ensure that the graphics and texts of different colors can be accurately registered on the substrate within the allowable error range.
When calibrating the register accuracy, use high-precision measuring tools such as magnifiers, microscopes, or electronic register measuring instruments to ensure the accuracy of the measurement results and keep calibration records for subsequent tracking and analysis of the performance changes of the printing machine.

(II) Calibration of Pressure Uniformity
Use pressure test films or pressure distribution measuring instruments to detect and adjust the pressure distribution between the printing cylinder and the plate cylinder and between the impression cylinder. Ensure that the pressure is uniform across the entire printing width to avoid quality problems such as uneven printing density and dot deformation caused by uneven pressure.
Based on the pressure test results, make appropriate adjustments to the parallelism of the cylinders and the thickness of the liners to make the pressure uniformity meet the printing process requirements. During the adjustment process, make gradual fine adjustments to avoid excessive adjustment causing damage to the equipment and repeat the test until the desired pressure uniformity effect is achieved.

V. Management of Ink and Solvents
(I) Storage and Use of Ink
Store the ink properly in a cool, dry, and well-ventilated environment, avoiding direct sunlight and high-temperature environments to prevent the ink from deteriorating, drying, or losing performance. Ink should be classified and stored according to the production date and model and labeled clearly. Follow the principle of first in, first out when using.
When using ink, select the appropriate ink brand and model according to the printing process requirements and the characteristics of the substrate, and strictly follow the technical parameters provided by the ink supplier for preparation and use. Avoid mixing different brands and models of ink to prevent affecting the printing quality and the stability of the ink.

(II) Selection and Use of Solvents
Select a solvent that matches the ink to ensure that it can effectively dissolve the ink without corroding or damaging the components of the printing machine. When using solvents, pay attention to their volatility and toxicity. Keep the workplace well-ventilated, and operators should wear appropriate protective equipment such as gloves, masks, and goggles.
Regularly check the purity and water content of the solvent. If the quality of the solvent decreases, replace it in a timely manner to avoid affecting the dilution effect of the ink and the printing quality. At the same time, strictly control the amount of solvent used to avoid waste and environmental pollution.
Through the above comprehensive and systematic maintenance measures, the normal operation of the flexographic printing machine can be effectively guaranteed, the printing quality and production efficiency can be improved, the failure rate and maintenance cost of the equipment can be reduced, reliable technical support can be provided for the printing production of enterprises, and the stable development of enterprises in the fierce market competition can be ensured.