On any given day, saw mills and other wood processing factories generate a significant amount of manufacturing by-product and scrap material. Much of these wood shavings and piles of sawdust are recycled and end up as an engineered wood product called particleboard. Other uses for wood scrap, such as incineration fuel for kiln drying lumber or co-generation of power, compete for these supplies. Particleboard is a value-packed alternative to solid wood paneling or boards. It is primarily intended for interior projects in which size consistency, smooth surfaces and a homogeneous construction are a priority.

Examine a section of particleboard and you'll most likely notice a lack of grain. Particleboard is produced by combining sawdust and other wood scrap with a special resin. This slurry of wood chips and glue is then pressed through an extrusion machine to form long sheets of particleboard. Customized saws cut these sheets into various sizes according to the needs of the customer. Countertop manufacturers use particleboard in a variety of sizes, but generally ¾" thick panels in 30" widths in 8’, 10’ and 12’ lengths are most suitable for countertop cores.

Although unfinished particleboard bears little resemblance to traditional hardwoods, its smooth, consistent surface is ideal for lamination. One of the things conventional particleboard cannot handle, however, is high exposure to moisture. This is why few if any outdoor projects feature particleboard.

Direct and/or prolonged contact with water can cause particleboard to stain, warp or swell.  Moisture resistance (MR) type particleboard perform much better in higher moisture applications. Particleboard is also used as sub-flooring, but only if it fits snugly enough to form a moisture barrier. Once particleboard become wet, it can lose much of its tensile strength.

Particleboard has many positive aspects. Waste wood materials are recycled to form a useful product, and consumers can purchase a very high quality countertop core product at competitive prices. Top quality particleboard is surprisingly durable and serves as the foundation for a beautiful laminate countertop installation that holds its good looks and functional features for years to come.

For more information about particleboard from the Composite Panel Association:

 

Particleboard has been in use since the 1940s and is commonly used in place of plywood for countertop core materials. Modern particleboard is now made primarily by combining wood shavings; chips and sawdust with a strong resin and pressing the mixture into serviceable boards ideally suited for laminate countertops.

The process of making particleboard begins with real wood. Most particleboard manufacturers use waste wood products collected from commercial woodworking factories, although some virgin wood may be used as well. All of this recycled wood fiber and sawdust is stored in large containers before being processed into particleboard.

The wood particles are dried, then milled sorted to eliminate overly large or small pieces. Once this mechanical sorting has been completed, the acceptable wood fibers move by conveyance to a blending hopper. Along the way, several overhead nozzles spray the wood fibers with a strong liquid resin or glue. Several different forms of formaldehyde-based resins may be used, depending on the specific quality of particleboard desired.

The resin-soaked wood is then blended to form a consistent paste. This combination is piped into a forming machine, which presses out a sheet of uncured particleboard. The formed panels of particleboard are then pressed down for easier transportation to the final curing ovens. Individual sheets of particleboard are held under pressure as the air around them is superheated. This allows the resin to harden and form a very strong bond with the wood fibers.

Some forms of particleboard are left in this rough state for use in flooring and other projects in which the panels will not be visible. For countertop manufacturing, high-pressure laminate (HPL) is bonded to the working surface of the particleboard.