Colloidal stability of Pinus radiata wood extractives. Part 2: Competing interactions between wood extractives and process variables determined from regression modelling

This paper presents the results of regression modelling undertaken to investigate the factors affecting colloidal stability of wood extractives from Pinus radiata. A factorial experiment was conducted to investigate the effect of process variables such as pH, soluble calcium, temperature, dissolved organic material on the colloidal stability of wood extractives at two different levels of wood extractives representative of the maximum and minimum levels in P.radiata extractives. Modelling of the total extractives resulted in poor predictive models. Modelling of the individual wood extracts was found to be more reliable with two way and three way interactions occurring between the process variables. Competing interactions between the process variables and the components were evident.