Starch is an important constituent in papermaking and it contributes to papermaking by providing functional properties and serving as a process aid. Starch utilization in papermaking depends on the type of paper, other raw materials used, papermaking technology, desired end properties, and paper machine productivity needs. Mixing cooked, modified wet-end starches with the pulp improves strength, sizing, retention, drainage, formation, wastewater quality, and productivity. In coated grades, starch acts as binder and rheology modifier in the aqueous coating and reduces costs by replacing expensive synthetic chemicals. The advantages of modified starches over native starches are manifold and include increased productivity and improved quality. With increased use of alkaline papermaking, starch has become an essential part of alkaline sizing programs while starch used as a polymer has become essential for microparticle retention systems. The changing needs of papermaking have provided the opportunity for starch manufacturers to develop newer grades of starch to help improve paper quality and productivity.
