The development of practical processes, involving electron preirradiation, for large-scale production of graft copolymers of starch with acrylamide (AA) and acrylic acid (AAc) was studied. In the pilot plant built to explore the continuous production of AA- and AAc-starch grafts, starch was fed continuously to a vibrating trough which transported the starch as a thin layer under the beam of a 1-MeV resonant transformer. The irradiated starch then fell into a tank where it reacted with a solution of either AA or AAc fed simultaneously to the tank reactor. Large samples of AA- and AAc-starch grafts were prepared at various grafting levels, and their physical and chemical properties were determined. Process flow sheets were prepared, and preliminary investment and production cost estimates were made for plants capable of producing 5 000 000 lb annually.