angles or of veneer in combination with a core of lumber
or of reconstituted wood. The usual constructions have an
odd number of layers.Wood Failure. The rupturing of wood fibers in strength
tests of bonded joints usually expressed as the percentage of
the total area involved that shows such failure. (See Failure,
Adherend.)
Wood Flour. Wood reduced to finely divided particles, ap‑
proximately the same as those of cereal flours in size, ap‑
pearance, and texture, and passing a 40 to 100 mesh screen.
Wood Substance. The solid material of which wood is
composed. It usually refers to the extractive‑free solid
substance of which the cell walls are composed, but this is
not always true. There is not a wide variation in chemical
composition or specific gravity between the wood substance
of various species. (The characteristic differences of species
are largely due to differences in extractives and variations in
relative amounts of cell walls and cell cavities.)
Wood‑Thermoplastic Composite. Manufactured com‑
posite materials consisting primarily of wood elements and
thermoplastic. The wood element may either serve as a rein‑
forcement or filler in a continuous thermoplastic matrix, or
the thermoplastic may act as a binder to the wood element.
Wood Wool. Long, curly, slender strands of wood used
as an aggregate component for some particleboards and
cement‑bonded composites. Sometimes referred to as
excelsior.
Workability. The degree of ease and smoothness of cut ob‑
tainable with hand or machine tools.
Working Life. The period of time during which an adhe‑
sive, after mixing with catalyst, solvent, or other compound‑
ing ingredients, remains suitable for use. Also called pot life.
Working Properties. The properties of an adhesive that
affect or dictate the manner of application to the adherends
to be bonded and the assembly of the joint before pressure
application (such as viscosity, pot life, assembly time, set‑
ting time).
Xylem. The portion of the tree trunk, branches, and roots
that lies between the pith and the cambium (that is the
wood).
Yard Lumber. (See Lumber.)
G–17
Glossary