Meaning
Water-soluble synthetic polymers are used in paper coatings to bind mineral pigments and stabilize optical brightening agents. A polyvinyl alcohol carrier ensures that these brighteners are distributed evenly across the surface of the paperboard. This carrier improves both the mechanical strength and the optical properties of the board.
Coating Binding
Surface coatings must adhere firmly to the paper fibers to prevent dusting and peeling during high-speed printing operations. The polyvinyl alcohol carrier acts as a highly efficient binder that holds the clay particles and optical brighteners in place. This binding creates a smooth and durable surface that is highly receptive to offset and flexographic printing inks.
Performance Specification
Purchasing boards for high-yield color printing requires strict control over the surface chemistry of the substrate. When a polyvinyl alcohol carrier is used, it enhances the brightness and fluorescence of the board by preventing the chemical quenching of optical brighteners. This enhanced performance allows printers to use less ink to achieve the desired color saturation, which directly reduces their variable manufacturing costs.
Supply Contract
Technical agreements between board mills and packaging converters often specify the type of binders and carriers used in the board’s manufacture. If the mill switches from a premium polyvinyl alcohol carrier to a cheaper alternative, the board’s printability and brightness may suffer. Such unauthorized changes can violate the supply contract, leading to shipment rejection and a loss of preferred supplier status, making material consistency a major commercial requirement.
