Wood Panels

Products in these industries are made from either solid timber or from sawdust, shavings or chips and increasingly other materials (such as bark). Veneer, plywood and laminated veneer lumber (LVL) are all made from high quality logs. Particle board and MDF (medium density fibreboard) are made from sawdust, shavings and chips – usually byproducts of the wood manufacturing and joinery industry.

Veneers
A veneer is a very thin flat sheet of wood made by either peeling or slicing logs. Logs are rotated at high speed in giant lathes to produce a long strip of thin peeled wood. Another process uses a giant knife to slice thin wood strips from logs. The veneer strips are then trimmed, sized, dried, graded and sorted. Sliced veneer is usually glued onto board such as MDF to make it look like solid wood. Typical applications include kitchen cabinets. This process, called overlay, can also be applied with other high value cover sheets (like foils, photographic paper or Formica).

Plywood
A thin layer of glue is applied to the veneers, they are then sandwiched in layers and pressed together to make a strong, stable flat panel. The average plywood sheet has between 3 and 10 layers of veneer. Knotty veneer is usually in the centre part of the panel while high quality knot free veneers will be used for the top sheets. Plywood is more stable than solid wood because each layer is placed with its grain at right angles to the previous layer. Expansion or contraction in any one veneer layer is restricted by the wood fibres in the adjacent one. This eliminates the large dimensional and strength variations that occur across the grain in solid wood. Plywood is used in construction because it can withstand large racking forces that may be imposed on a structure (earthquake).

Laminated veneer lumber (LVL)
The production process for LVL is similar to making construction grade plywood, with three main differences. The sheets are much thicker than plywood (up to 75 mm), each veneer sheet is laid with the wood grain oriented in the same direction and continuous lengths of up to 25 m can be produced. Continuous presses are used to manufacture LVL and the material is cut to the required dimension. Laminating improves the strength of wood by dispersing the weakness from defects (e.g. a knot) over a greater area. In effect, it increases the strength of the weakest part of a length of wood. LVL is used for structural beams, joists, scaffold planks, truss stock and for joinery work.

Particle and fibreboards
Particleboard is any board that is made from wood particles (as opposed to wood fibres or sheets of wood). There are many types, ranging in particle size, orientation and position. They include particleboard, flake board, oriented strand boards (OS B) and wafer board. These products are mainly used for structural purposes such as wall bracing and flooring and offer similar structural properties to plywood.

Fibreboard includes hardboards, insulation boards and medium density fibreboards (MDF). Fibreboard can be produced from low-grade wood and mill residues. The wood is reduced from chips to wood fibre and then, depending on the product being manufactured, undergoes a process of either dry or wet felting. Chemicals and resins are added, and the mixture is then formed into a continuous mat. Heat and pressure is applied to create panels, which are then cured, finished and sanded, and cut to market size.

Triboard features a flakeboard core and MDF surfaces for a smooth finish. Both these products combine the strength properties of particle board with the appearance qualities of the MDF panel.

Whatever the product, from that first cut in the log to the end result, every step of the process depends on people with knowledge, technical skills and good judgement.