Definition
Flexo proofing machine is a special experimental testing equipment that simulates the flexographic printing process. It is mainly used to reproduce prints that are similar to actual production in a small-scale and controlled way before official printing. Its core function is to verify and evaluate inks, substrate materials, printing plates and printing process parameters, providing reliable data support and quality prediction for subsequent mass production.
How it works:
The working principle of flexo proofing machines is based on the basic mechanism of flexographic printing. The equipment usually includes an ink supply system, plate roller, substrate platform and pressure regulation mechanism. During work, the ink is quantitatively transferred to the graphic part of the flexible printing plate through the anilox roller, and then under the preset pressure, the printing plate contacts the substrate and transfers the ink to the surface of the substrate. The ink transfer process can be simplified into a transfer rate model, and the common expression is:
TR = (Ms / Mp) × 100%
where TR represents the ink transfer rate, Msrepresents the amount of ink on the substrate, MpRepresents the amount of ink on the printing plate. The process is influenced by a synergy of various factors such as pressure, speed, and material surface properties.
Measurement and evaluation methods
When using flexo proofing machines for evaluation, the main focus is on quantitative indicators of print quality. Color measurement is usually done using a spectrophotometer, which obtains the chromaticity value L*a*b* and the chromatic aberration ΔE to evaluate the accuracy of color reproduction. Printing uniformity can be determined by measuring the density of the ink layer in different areas and calculating the density deviation. The dot enlargement is analyzed by microscope or special software to analyze the change in the shape and area of the dots on the proof. In addition, ink adhesion and drying properties can also be verified by auxiliary methods such as grid testing and friction testing. These measurements refer to relevant industry standards, such as ISO 12647-6 and other international or national specifications.
Analysis of influencing factors
The accuracy of the proofing results is affected by multiple factors. In terms of process parameters, printing pressure, speed and number of anilox rollers directly determine the thickness and transfer uniformity of the ink layer. Among the material factors, the hardness and elasticity of the printing plate, the surface energy and ink absorption of the substrate, and the viscosity and rheology of the ink all play a key role in the reproduction of graphics and texts. Environmental conditions such as temperature and humidity can affect ink drying and material dimensional stability. Operational specifications, including equipment calibration, material installation tension control, and cleaning and maintenance, are also important aspects to ensure reliable proofing results.
Applications:
Flexo proofing machines are widely used in R&D and quality control links in packaging printing, label printing, flexible packaging and paper products. In packaging material development, it is used to test the printability of new films or papers. In the labeling industry, it is possible to verify the reproduction of complex color combinations and fine lines. In addition, the equipment is also commonly used for printing process research, ink formulation optimization, and operator skills training to help users anticipate and resolve potential problems before entering production.
Equipment selection
When selecting, it is necessary to comprehensively consider technical parameters and actual needs. The size of the proofing format should cover common product specifications. The pressure and speed adjustment range should meet the printing process conditions to be simulated. The accuracy and repeatability of the ink supply system have a great impact on the consistency of the results. Whether the device supports multiple substrate types and whether it is easy to integrate quality control tools such as color measurement is also an aspect to consider. At the same time, the convenience of equipment operation, maintenance costs and the technical support capabilities of suppliers should be weighed in the decision-making process.