Polymer Binder
Coating and treating paperboard surfaces often relies on synthetic polymer emulsions to improve the surface finish and liquid resistance of the packaging material. The application of styrene acrylic copolymers provides a versatile binding medium that balances the rigidity of styrene with the flexibility of acrylic monomers. It forms a continuous film when dried on the cellulose fiber network.
This polymer prevents ink bleed and enhances the gloss of printed packaging. It sits on the surface of the sheet to create a uniform barrier that is compatible with both water-based and solvent-based printing inks.
Barrier Performance
Applying this polymer emulsion improves the resistance of the paperboard to water penetration and grease migration. The hydrophobic styrene segments limit the diffusion of water molecules through the coated layer. This barrier prevents moisture from softening the paper fibers during transport and cold storage.
It extends the shelf life of food packaging.
Shearing Resistance
High-speed coating operations require the polymer binder to remain stable under high shear rates without coagulating or breaking down. The copolymer must resist the mechanical forces exerted by blade or rod coaters. This stability ensures a smooth, defect-free coating layer across the entire web.
The process completes when the coating is dried in the oven.
