Course: Manufacturing II Unit: Material ID

 Lumber is various lengths of wood used in the construction and furniture making trades.

 Starts with tree  Cut/debranched and sent to sawmill  Sorted and cut  Circular saw  Band Saw  Dried  Air  Kiln  Grade  Distributed

 Visual inspection  Size  Shape  Marked to be felled  *Felled – the process of cutting down a tree

 After a tree is felled it is sent to the Saw Mill  at Saw Mill  Debarked  Grinder  Water jets

 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)

 Lumber is Graded  Sent to Lumber yard to sold to you

 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.

 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.

 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 percent.

 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.

15 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.