Surfactant Migration Impact on Dynamic Surface Tension in Hardwood Stock
Residual surfactant migration in hardwood stock depresses dynamic surface tension below forty millinewtons per meter, triggering jetting print defects.
Silicone Polyethers
Copolymer Additive
Copolymer additives combining silicone backbones with polyoxyethylene chains are used to modify the flow and wetting characteristics of industrial coatings. Incorporating silicone polyethers into water-based varnishes reduces surface tension without causing the severe foaming or cratering associated with traditional defoamers. These unique materials act as both wetting agents and flow control additives on high-speed printing presses.
Structural Function
The chemical structure of these polymers features a flexible silicone segment that provides low surface energy and a polyether segment that ensures water solubility. This balance allows the molecules to migrate rapidly to the liquid-gas interface during the coating application. When silicone polyethers are used, they improve the leveling of the varnish, eliminating brush marks and surface imperfections.
This molecule design ensures that the dry coating provides a smooth, non-blocking surface that resists scratching.
Ink Performance
High-speed flexographic and gravure printing systems require coatings that can wet low-energy synthetic or recycled paperboard surfaces. Poor wetting leads to reticulation, where the wet film breaks up into islands and leaves exposed patches of substrate. Adding these specialized surfactants prevents this defect by ensuring a uniform ink film spreads over the surface.
The resulting gloss and protection satisfy the rigorous demands of premium packaging producers.