Hardwood veneers can be applied
to several different core types. Choice of a core composition
depends on the panel’s ultimate use (see Fig.
Veneer Core Construction
Lumber Core Construction
MDF Core Construction
Where excellent matching properties are needed, individual
strips of wood are edge-glued to form a solid slab lumber
core. Although slightly higher in cost, lumber core is
often preferred because edges can be shaped and matched
to finished surfaces without filling. Thicknesses normally
range from 3/4 to 1-1/8, but may be specified
thicker for special uses.
Veneer Core: Because of its moderate
price and high strength, veneer core hardwood plywood
is first choice for many applications. Hardwood plywood
1/2 or less is usually specified with veneer core.
However, thicknesses range from 1/8 to 3/4.
All plies are less than 1/4, ranging in odd numbers
from 3 to 7 (depending upon thickness). Veneers are bonded
with water-resistant resin adhesives.
Density Fiberboard: is manufactured from pressure
cooked wood chips which are broken down into fibers and
combined with resin and wax and pressed into panels. Because
medium density fiberboard uses wood fibers, the end product
is solid–the compressed fibers make it very dense.
It can be machined or sanded to a smooth finish. It is
heavy, however, at about 96 pounds per 4' x 8' x 3/4"
panel. It is typically almost twice as heavy as veneer
core plywood–and may warp if not handled correctly.
Particle Board Core: Particleboard is
constructed from wood particle rather than processed fibers.
The wood particles are blended with resin and wax and
pressed into panels. It is firm and solid throughout and
makes a good core for hardwood plywood, however, it will
not machine and sand as well as medium density fiberboard
or veneer core. It is also heavy at about 93 pounds per
4' x 8' x 3/4" panel.