Some of the key factors which affect Kraft pulp quality are the raw material performances. The availability of the forest resource, the
great diversity of the French species, the fluctuating price of wood place are the different aspects French pulp mills have to take into
account. In this context, using a mix of species, hardwood or softwood, is particularly interesting for plants. The optimization of the
mixes is therefore a main question.
Here we present the AFOCEL's investigation of the effect of a mix of hardwood or softwood species during Kraft cooking on yield. In
this work, height main French species (4 softwood and 4 hardwood) were studied. In the first part, a methodological approach is
presented which is supported by the mathematical model of Scheffé (a simplex-centroid mixture design augmented with three interior
points). In the second part, results are presented.