Backs: The reverse side to the face of a plywood panel. Generally, the
poorer side of any grade plywood panel calling for a face and a
back.Bark Pocket: A small area of bark around which normal wood has
grown.
Burl:
A swirl or twist in the grain of wood, usually occurring near a knot, but which itself
does not contain a knot.
Core:
The innermost portion of plywood usually composed of veneer. Also referred to as a
"center." A core may also be made of fiberboard, particleboard or lumber.
Crossbar:
An imperfection or irregularity in the grain of wood running at right angles to the length
of the board.
Crossbanding:
Inner ply veneer placed at right angles to the core, face and back of a plywood panel.
Defects:
Anything interrupting the smooth flow of a wood surface. This includes loose knots,
splits, voids, wormholes, bark pockets and others.
Delamination:
The separation of the inner plys in a panel due to the failure of the adhesive bond.
Face:
The best side of a plywood panel in which the outer veneers are of different grades.
Grain:
The pattern, size and direction of the fibers in wood or veneer.
Gum
Spots: Accumulation of resinous material often found on panel surfaces. May be
removed by sanding.
Half-Round
Slicing: Off-center slicing cut slightly across the annular grown rings
resulting in half-round, plain sliced or rotary characterisitics.
Hardwood:
General term referring to the wood of many different desiduous trees as opposed to the
softwood of evergreen or coniferous trees. Does not relate to the density of the wood.
Heartwood:
The center portion of a tree consisting of mature wood that has stopped growing. Generally
distinguishable from sapwood or the growing outer portion by its darker color.
Knot:
circular portion of a board or veneer that was once the base of a branch or twig growing
from the trunk of a tree.
Knot
(Open): Opening produced when a portion of a knot has dropped out or separated
due to seasoning.
Knot
(Pin): Sound knots less than 1/4" in diameter.
Knot
(Sound): Knots that are solidly fixed by growth and retain their place in
lumber or veneer.
Knothole:
Opening produced when knots derop from the wood in which they were once embedded.
Lap:
The overlapping of one piece of veneer on another in the same layer of ply.
Medium
Density Fiberboard (MDF): A panel or core material manufactured from pressure
cooked wood fiber, resin and wax.
Mineral
Streak: A discoloration of hardwood and hardwood veneer.
Particleboard:
A panel or core material manufactured from pressed sawmill shavings, resin and wax.
Patches:
Filler material inserted into defects of veneers or panels for repair.
Plain
Sliced: Veneer sliced from a log tangent to the tree's annual rings.
Ply:
A single sheet of veneer forming one layer in a multi-layered piece of plywood.
Plywood,
Hardwood: A panel composed of layers of inner plys, or other core material
joined with an adhesive to a face veneer of hardwood and a back veneer, usually also
composed of hardwood.
Quarter
Slicing: Quartered log sliced at right angles to the growth rings.
Rift
Cut: Veneer cut from a quartered log on a 90 degree angle to the grain.
Rotary
Cut: Veneer peeled from a whole log set in a lathe and turned against a special
knife.
Sapwood:
The light colored, living portion of a tree located between the heartwood and the bark.
Slip
Matched: Veneer sheets that are laid side by side to form a whole sheet with a
repetitive grain appearance.
Splits:
Separations of the wood fiber running parallel to the grain.
Veneer:
Peeled or sliced thin sheets of wood used as inner plys or as decorative faces. |
