THE ACTION OF STARCH IN THE NEW PAPER - W ASTE PAPER CYCLE

The German paper industry consumes over 220 000 t of starch per year; this corresponds to a specific input of 18 kg/t paper The principal qu antity of 80% is applied to the surfaces, the remainder are 8% in pigm ent coating, 7% as beater additive and 5% applied as spray. Additional ly about 70000 t.p.a. are used as adhesives in the corrugated paper an d paper finishing industries. A considerable quantity of the papers wh ich have been treated with starch returns to the raw material cycle in the form of production waste and waste paper. The starch used by the paper industry thus presents a considerable potential for microbiologi cal growth in the water systems of paper machines. The amount of burde n in a water system depends on the extent to which the starch has been modified. The application technology and the kind of starch used shou ld, from this point of view, be selected not only on the basis of econ omy but also considering the general ecology.