Wood processing

Once the forestry companies have felled trees, the logs must be processed into other products. These processes are varied and each present their own problems.

Bark removal

The bark of the trees must be removed since it is never utilised with the underlying wood. Unfortunately bark varies widely in its texture, thickness and ease of removal. The bark often contains mud and grit that could damage saws and cutters.

Bark

Chipping

Logs are sometimes chipped to provide feedstock for paper and panel manufacture and other uses. Chips are also a side product from the sawline. Chipping technology development has to incorporate control of chip size and shape, minimal power consumption, low cutter wear and minimal dust production.

Sawing

Primary sawmilling of logs has advanced dramatically in the last twenty years. Both bandsaws and circular saws have been developed for maximum rate of production, improved finish, thinner kerf and longer cutter life. This has been achieved by development of better materials for saw body and cutter, better sharpening technologies and improved accuracy in pre-stressing of blades. In secondary processing, saw and cutter technology has enabled greater accuracy and extremely long life. The use of diamond tips has enabled economic processing of abrasive materials like wood chipboard and melamine coated boards.

Planing, moulding and milling

To achieve accurate dimensions and good surface finish, cutter systems have been developed that enable long cutter life with lower noise and quicker set-up times. Planing speeds of 300 metres per minute are possible. Research continues to enhance cutter life.

Abrasives

Final finishing and calibration of components require the use of abrasives. This brings with it many problems, such as monitoring wear and final finish.

Finishing

Wood based materials usually have a final finish applied. Since the use of solvents (VOCs) has been reduced, many problems remain to be solved in application, control of colour and service life. There is much overlap with the wood protection group.

 

Useful links

Wood Machining Institute

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