Pulping and bleaching OCC. Part III: Printed OCC

This paper describes the processing of printed old corrugated containers (OCC) into bleached pulps. Samples from six different OCC packagings were processed with the sequence: kraft pulping, oxygen delignification, ECF bleaching and hyperwashing. The resultant pulps were Characterised by determining the kappa number, yield and the contents of fines, ash and specks. The effects of screening OCC pulps and of their cleaning in the flotation process on the characteristics of OCC pulps were also determined. Properties of these bleached Nips from printed OCC were compared with those of bleached pulps, similarly processed from unprinted OCC and birch pulpwood.