Forest Products
» Primary Manufacturing
Primary Manufacturing
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The sawmill turns a raw log into a dimensional piece of wood, ready to be shipped to the construction or remanufacturing market. One by one, logs pass through the mill's "head rig" and are cut into square "cants." Each cant is run through a series of gang saws so that its most valuable lumber is recovered.
The sawyer sits near the head rig and operates a control panel. Despite the sawyer's skill, much of the decision-making is now done by computers. Logs and cants are optically scanned, and sophisticated software applications instantaneously "optimize" each piece--deciding precisely which sizes and lengths to cut to get the most use out of the log. It all happens in just seconds.
Bark, slabs, and sawdust fall through slits onto conveyor belts below. Some of this waste wood is used as "hog fuel" in the sawmill's boiler, which generates the steam and electricity used to run the plant. Other material is sorted and sold as pulp chips or "feedstock" for products such as particle board. Excess hog fuel is shipped to biomass power plants, which use these woody wastes to generate electricity. In other words, nothing is wasted.
The lumber is graded and sorted. Forklifts load lumber "units" into the dry kiln, which uses steam heat from the boilers to dry the lumber. Finally, finished units are loaded onto flatbed trucks or rail cars for shipment to distant markets.
And a fresh truck load of logs arrives at the sawmill from the forest, which in turn will soon be planted with young tree seedlings to provide habitat for animals and wood for the use and enjoyment of grandchildren not yet born.