Some hardboard manufacturers begin with roundwood or logs. In all cases, the sequence is the same, regardless of the locations in which these preparatory processes occur. Chips must be screened to prepare them for defibration. Oversized chips are returned for re-chipping. Sawdust and other fine particles are sifted and saved for use as fuel in the power plant.
Nothing is wasted.
Cooking Wood chips are cooked under heat and pressure to soften them and dissolve some of the natural resin in the wood. This allows the chips to be more easily reduced to fibers in the refining process. The sudden change in pressure between the inside and the outside of the chip causes it to explode into fiber bundles. This reduces the need for further refining. Refining The softened chips are fed into refiners where opposite rotating grinding disks shred them into fibers.