Characterization and Competitiveness of the French Wood Supply for the Kraft Pulp Manufacturers. Mixed Hardwood Kraft Pulp: Modelling and Optimising, 2001 Pulping Conference Proceedings

S. Medina, C. Deleuze-Brezins, G. Chantre--One of the key factors which manage Kraft pulp quality is the control of the performances of the raw material. But the availability of the forest resource, the great diversity of the French species, the fluctuating price of wood place the pulpmakers under economical pressure. Especially for the plants using a mix of species, hardwoods or softwoods, the main question is how to optimise the mix ? Two main aims become apparent:

• The quality of the end product: pulp and paper. How do the physical properties of the mix vary ? What is the most interesting mix to choose ?

• The cost-effectiveness of the mill: a better knowledge of the performances of mixes of species can allow the mill to adjust the wood supply politics.

The objective of this study is to investigate the behaviour of a mix of hardwood species during Kraft cooking and to predict its pulp properties. The first step of this work was to adopt a methodology allowing us to study different mixes of hardwood species with a limited number of experiments. The second step was to modelling the results as pulp yield, fibre morphology and physical strength properties by response surfaces fitted at Kappa number 18.