Water-Developable Flexographic Plate Wrinkle Prevention
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Solution Overview
Problem
Flexographic printing plates developed using the Computer to Plate Technique with water-developable photosensitive resin layers, particularly those containing latex, often suffer from wrinkles and surface abnormalities due to their flexibility and sensitivity to oxygen inhibition, which existing solutions fail to completely address.
Innovation Solution
A flexographic printing original plate is designed with a laminated structure comprising a supporting member, a photosensitive resin layer, and a protective layer containing polyvinyl alcohol, plasticizer, and water-dispersible latex in specific weight ratios, which prevents polymerization inhibition and heat damage, ensuring a wrinkle-free and abnormality-free surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a protective layer with high elastic modulus is used on the photosensitive resin layer, then the plate maintains structural stability, but wrinkles are generated on the plate surface when the plate is detached from the drum
Solution Approach 1:
The patent changes the elastic modulus parameter of the protective layer by selecting specific materials (polyvinyl alcohol, polyethylene glycol, polypropylene glycol) and controlling their molecular weights and compositions. This creates an optimal balance where the protective layer has sufficient stability during laser processing but low enough elasticity to prevent wrinkle formation upon detachment
Solution Approach 2:
The protective layer is formulated as a composite material containing multiple components: polyvinyl alcohol (5-50 wt%), polyethylene glycol (10-40 wt%), and polypropylene glycol (10-40 wt%). This composite structure allows the layer to exhibit both structural stability during processing and flexibility to prevent wrinkles after detachment
2Shape
If a protective layer with low elastic modulus is used to prevent wrinkles, then the plate surface remains flat after detachment, but the protective layer is damaged by heat during laser ablation
Solution Approach 1:
The patent optimizes the molecular weight parameters of the polyethylene glycol (2,000-10,000) and polypropylene glycol (2,000-10,000) components. These specific molecular weight ranges provide the protective layer with sufficient heat resistance to withstand laser ablation while maintaining low elastic modulus to prevent wrinkle formation
Solution Approach 2:
The protective layer uses a composite formulation where polyvinyl alcohol provides structural framework, polyethylene glycol contributes to flexibility and heat resistance, and polypropylene glycol enhances thermal stability. This composite structure simultaneously achieves wrinkle prevention and heat resistance
3Shape
If the protective layer is omitted to prevent wrinkles, then the photosensitive resin layer directly contacts the mask layer, but polymerization inhibition occurs due to oxygen in the air
Solution Approach 1:
The protective layer acts as an intermediary between the photosensitive resin layer and the mask layer. It provides an oxygen barrier to prevent polymerization inhibition while maintaining plate surface flatness. The layer's specific composition (polyvinyl alcohol, polyethylene glycol, polypropylene glycol) creates an effective oxygen barrier without causing wrinkle formation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The proposed solution effectively prevents wrinkles and surface abnormalities, providing a flexible, water-developable printing plate with enhanced heat resistance and oxygen barrier properties, resulting in a high-quality printing surface.
Implementation Method 1
the protective layer has a function of preventing the mass transfer between the photosensitive resin layer and the infrared-sensitive layer and of preventing the polymerization inhibition of the photosensitive resin layer due to oxygen in the air
Implementation Method 2
by evaporating this infrared sensitive layer by using an infrared laser, an image mask is formed
Implementation Method 3
an infrared sensitive layer that is opaque to chemical rays is formed on a photosensitive resin layer and by evaporating this infrared sensitive layer by using an infrared laser
Implementation Method 4
a photosensitive resin layer, protective layer and infrared sensitive layer... preventing the polymerization inhibition of the photosensitive resin layer due to oxygen in the air
Data Source
AI summary
The present invention provides a flexographic printing original plate having no wrinkle on the plate surface and having no plate surface abnormality due to laser in spite of the fact that it is a flexible water-developable plate. A photosensitive flexographic printing original plate developable by water in which at least a supporting member, a photosensitive resin layer, a protective layer and a heat-sensitive mask layer are successively laminated, characterized in that, the protective layer contains (A) polyvinyl alcohol, (B) plasticizer and (C) water-dispersible latex in the following rate. Polyvinyl alcohol (A): 25 to 80 parts by weight Plasticizer (B): 15 to 60 parts by weight Water-dispersible latex (C): 5 to 40 parts by weight