Pilot plant studies on the thermomechanical pulping of western hemlock

Thermomechanical pulps made in Paprican's pilot plant front western hemlock slabwood gave more long fibres and better strength properties at a given freeness dian those from roundwood. Reducing the refiner rotational speed from 1200 rpm to 900 rpm in the post-primary stages led to a slight increase in the energy consumption and the long Fibre content. However the effects were relatively small. Increasing the rotational speed to 1800 rpm, reduced the energy consumption, fibre length, TEA and burst at a given freeness, while increasing the light scattering coefficient.