Laminated Veneer Lumber (LVL) is an engineered wood product that provides a consistent, high-performance alternative to solid lumber and steel in structural uses.
Report from Scion for Carbon Footprint of NZ Laminated Veneer Lumber - December 2010
Log Yard: Pulp and Veneer logs are delivered to the log yard for both the MDF and LVL processes.
Debark Logs: All bark is removed from the logs in a tandem ring debarker that uses knives to strip the bark from the trees. The maximum capacity of the debarker is a log of approximately 850mm diameter. After the debarker the logs are cut to either 2650mm or 2950mm lengths suitable for the lathe.
Hot Log Bath: The logs are conditioned in hot (85 degrees Celsius) water for 24 hours. This brings the core temperature of the logs up to 65 degress Celsius and allows a smoother peel to be achieved. When logs have reached the required core temperature the gantry crane loads a conveying system to the lathe infeed.
Lathe Peeling: The Wood Lathe scans the log profile using 7 lasers, then centres the log for the most efficient recovery of material and peels the logs to a core diameter of 78mm. All round-up, waste veneer and cores are converted into chip, which is used in the manufacture of MDF.
Clipped to Size: The ribbon of veneer is conveyed on three tipple decks, scanned by camera for holes, analysed for moisture content and clipped to width by a rotary clipper. Veneers are clipped to a wet width of 1.3m then stacked according to their moisture content.
Veneer Drying: Veneer sheets are dried in the machinery, 22 bar, steam powered, six deck, veneer drier. The veneers are dried in three stages to a target moisture content of between 8 and 10%.
Structurally & Visually Graded: As the veneers come out of the drier they are automatically graded by a nine option system for specific customer requirements and for LVL production in the plant by various machines like:
– Babcock NovaScan 4000 camera for surface appearance
– Metriguard 2800 DME for density and stiffness
– Elliot Bay Cypress 2000 moisture detection system.
This is a completely automated grading system. Some veneer is exported for further processing, while most is used for production of LVL.
Scarfing: The veneer edge is scarfed for a uniform thickness at the joints between veneers in the layup process. All veneers used in LVL are scarf jointed. This results in a stronger product than when butt or overlap joints are used.
Glue Applied: At the layup station stacks of core sheets, face sheets and make-up sheets (able to be placed in any position) are vacuum lifted onto the processing line according to the press recipe. The veneers are then curtain coated with phenol formaldehyde, an exterior grade adhesive.
Continuous Press: Once the veneers have had the glue applied the veneers are skew aligned then laid up into a mat. The veneer mat passes through a 300kW microwave to begin the heating process from the inside the veneer mat and then into the continuous 45 metre hot press where the hot oil platens complete resin cure and an LVL billet is formed. The billet can vary in size between 12 and 120mm thick, is produced to a width of 1.2m, and can be up to 18m long.
Sanding: The online four-head sander is an optional part of the production process for products that require a sanded finish.
Cut to Width: The billets are ripped to widths required by the customer. We can cut to widths of between 63 and 1200mm. Each piece of LVL is also marked with an inkjet print marking and paint spraying system with the companies logo and grade for clear visual identification.
Packed and Wrapped: LVL is packed into sizes of packs of approximately 300mm (high) x 1000mm (wide) for forklift handling. The packs are wrapped with plastic wrap showing the companies logos. Packs are transported to the Port of New Zealand production regions for shipment to customers around the world.
View the LVL process in a flowchart format
Download an overview of our plant and the LVL production process (PDF)
Members who make LVL Products:
HTL Group Ltd
Juken NZ Ltd
Nelson Pine Industries
Timberlab Solutions Ltd