CORE CONSTRUCTIONS
Hardwood veneers can be applied to several different core types. Choice of a core composition depends on the panel’s ultimate use (see Fig. 2).

Veneer Core Types:
Multi-ply Veneer Core Construction Three-ply Particleboard Construction
Five-ply Lumber Core Construction Three-ply MDF Core Construction

Lumber Core: 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.
Medium 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.

©2008 Industrial Plywood, Inc.