The reason for this is the limited freedom of movement as the filling level increases, which means that the grinding balls do not reach their maximum speed. This in turn reduces the kinetic energy and thus the energy input. If the filling level would be increased further, a decrease in the soluble fraction would be expected. This fact matches with results from literature, where too high filling levels reduced the energy input. 0 10 In the relevant range of the filling level between 10 % and 30 %, no influence on the weight average molecular weight (Table ) can be determined. As in the previous sections, the influence between polymerization and depolymerization is expected at high soluble fractions near equilibrium.