Modified Starch as a Retention Aid in Papermaking

Clay particles added to fibers are not easily retained in the forming sheet so the mechanical properties of paper suffer. Modified starches and polyacrylamide (PAM) are used as retention aids for clay and strengthening agents. Modified starch is a better strengthening agent and retention aid than is polyacrylamide. The high retention of clay can be obtained by using modified starch and PAM. Heated kaolin at 800°C is retained better than unheated...