Flexographic Printing Plate Uneven Surface Ink Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flexographic printing plates face issues with ink transferability and density in solid portions, with existing solutions failing to adequately improve these aspects, leading to printing unevenness and low ink density.
Innovation Solution
A flexographic printing plate with a relief layer featuring an uneven structure on its surface, characterized by specific roughness parameters such as an average length of roughness curve elements between 15 to 120 µm, an oil-retention volume of 2 to 180, and a load length ratio of 20% to 90%, enhancing ink transferability and allowing for high ink density printing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a fine screen is arranged to cover a print point to enlarge the surface area, then the ink attachment amount increases, but the ink transferability in solid portions cannot be sufficiently improved and ink density is lowered
Solution Approach 1:
The invention changes the surface roughness parameters of the relief layer by controlling the average roughness Ra to 0.1-0.6 μm and root mean square roughness Rq to 0.05-0.25 μm. This parameter optimization enables both sufficient ink attachment and high ink transferability, resolving the contradiction between ink quantity and transfer quality.
Solution Approach 2:
The invention applies different surface quality characteristics to different areas: the solid portion (image area) has a controlled rough surface with specific Ra and Rq values to enhance ink attachment, while maintaining appropriate relief height for transfer. This local differentiation of surface properties allows simultaneous optimization of ink holding and transfer efficiency.
2Manufacturing precision
If the plate surface average roughness is increased to improve ink transferability, then ink transferability improves, but ink density in solid portions becomes low
Solution Approach 1:
The invention optimizes the relationship between average roughness Ra (0.1-0.6 μm) and root mean square roughness Rq (0.05-0.25 μm) to achieve balanced performance. This dual-parameter control ensures that the surface has sufficient micro-structure for ink transfer while maintaining enough surface area for high ink density, preventing the trade-off between transferability and density.
3Manufacturing precision
If a sandpaper or polishing film is used to adjust the surface of the print layer, then surface roughness parameters are modified, but solid quality in flexographic printing cannot be sufficiently improved
Solution Approach 1:
The invention establishes specific ranges for average roughness Ra (0.1-0.6 μm) and root mean square roughness Rq (0.05-0.25 μm) that optimize both surface quality and printing reliability. These precisely controlled parameters ensure consistent ink transfer and high solid quality, overcoming the limitations of conventional surface treatment methods.
Data Source
Figure 1~3
Figure 4~6A
Figure 6B~6E
AI summary
The present invention is to provide a flexographic printing plate having high ink transferability and making it possible to perform printing with a high ink density in a solid portion, a flexographic printing plate precursor, a method for manufacturing a flexographic printing plate, and a method for manufacturing a flexographic printing plate precursor. A flexographic printing plate includes a relief layer including a non-image area and an image area having an uneven structure formed on a surface thereof, in which an average length RSm of roughness curve elements of the surface of the image area having the uneven structure is 15 to 120 µm, an oil-retention volume A2 is 2 to 180, and a load length ratio Rmr 30% at a cutting level of 30% is 20% to 90%.