Influence of Autoclaving On Chemical Pulp Fiber Properties for Fiber-cement Applications

In order to evaluate the degradation of cellulose fibres during autoclaving of fibre-cement materials, the properties of chemical pulps submitted to autoclaving in alkaline solutions are studied. It is observed that significant changes in the fibre structure occur as reflected, among other things, by a lowering of the degree of polymerization and of the intrinsic fibre strength (zero-span breaking length). The influence of oxidation on fibre degradation during autoclaving is also studied. It is observed that oxidized fibres reach low levels of intrinsic viscosity after autoclaving, in the case of dichromate and of dichromate-acid chlorite oxidations