Design And Manufacture Flashcards
Equilibrium Moisture Content
When the moisture content is at equilibrium with relative humidity around it
Moisture content
Measure of water expressed as percent
Relative Humidity
Ratio of amount of moisture in the air at a given temperature to the maximum amount of moisture the air could hold at that temperature.
Free Water
water held in cell cavities, escapes wood relatively easily
Bound Water
Water held within cell walls, water is forced out slowly, wood cells shrink
Fiber Saturation Point
cell cavities are empty of water, while cell walls are fully saturated; point in the drying process where the cell begins to shrink
Wood Shrinkage
varies from species to species
lengthwise 1%
radially 4%
tangentially 8%
Air Dried Lumber
moisture content ranges from 5% to 14%
Kiln Dried Lumber
usually dried to about 7%
Pith
cells in the very center of the tree
Ray
cells that extend radially
Growth Ring
a ring growth produced each year
Early Wood (Spring Wood)
wood formed during the early weeks of the growing season
Late Wood (Summer Wood)
wood formed after the initial weeks of growing season
Flatsawn Lumber
lumber whose face orientation is approximately tangential to the pith
