LUMBER PROCESSING

Course: Manufacturing IIUnit: Material ID

What is Lumber? Lumber is various lengths of wood used

in the construction and furniture making trades.

Steps In Producing Lumber

Starts with tree Cut/debranched and sent to sawmill Sorted and cut

Circular saw Band Saw

Dried Air Kiln

Grade Distributed

The Tree

Visual inspection Size Shape

Marked to be felled *Felled – the process of cutting down a tree

The Saw Mill

After a tree is felled it is sent to the Saw Mill

at Saw Mill Debarked

Grinder Water jets

The Saw Mill Continued

Log cut to length or bucking

Log cut into strips the length of log Plain Sawn Quarter Sawn

Drying the lumber Air Dry (10-12% Moisture) Kiln Dry (6-8% Moisture)

The Saw Mill Continued

Lumber is Graded

Sent to Lumber yard to sold to you

Plain Sawn Lumber

Plain sawn wood is the type most typically seen today. When the log is cut in to planks all the cuts are parallel to each other.

Quarter Sawn Lumber

With Quarter sawn wood the log is first quartered (hence quarter sawn) and then diagonally from the center.

This results in a grain that is more vertical when looking at the plank end on.

Air Drying Lumber

To air dry the lumber is arranged in layers or courses

Separating stickers are place between boards and the boards are then stacked

Boards are stored outdoors so that atmospheric air can circulate through the piles and carry away moisture

Reduces moisture to about 10-12 percent.

Air Drying Lumber

Kiln Drying Lumber

Lumber is dried in a closed chamber

Controlling the temperature, relative humidity, and air circulation.

Wood reaches a predetermined moisture content.

Seven percent moisture – four to five days.

Kiln Drying

Kiln Drying

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Wood Structure

Radio Frequency (RF)

Heat waves, a unique technology utilizes electromagnetic waves

Radio Frequency spectrum to heat products within a vacuum controlled environment.

Heat wave kilns use amplifier based power generators to create the radio frequency field which heats each load.

Drying time for hardwoods – 24 hours.