On October 28, Roseburg Forest Products celebrated the opening of its new plant in Chester, South Carolina, featuring the world’s highest-capacity laminated veneer lumber (LVL) continuous press. President and CEO Grady Mulbery and Roseburg owner and Chairman Allyn Ford welcomed South Carolina Governor Henry McMaster and other state officials and business partners to the ribbon-cutting ceremony and plant tour.
Upon full production, the line will produce up to 285,000 m³ LVL per year, made possible by microwave preheating and continuous press technology. DIEFFENBACHER supplied the LVL press and the upstream 600 kW microwave, the most powerful preheating system of its type in LVL production.
To produce high-quality LVL, the veneers are evenly heated to 60–90°C in the microwave over the entire mat thickness. The special design of the DIEFFENBACHER CPS press infeed means the distance the mat has to travel “without pressure” upon leaving the microwave until reaching the maximum pressing pressure is less than 2,500 mm. This prevents pre-curing of the resin. Fast-hardening glue can be used to increase production speed and capacity.
In addition to boosting capacity, the ideal combination of microwave and CPS also enhances board quality. Compared to production on a multi-opening press, the continuously produced LVL boards have more consistent mechanical board properties and significantly lower thickness tolerances. Subsequent sanding is not necessary. For example, unsanded LVL boards can be used directly as scaffolding planks, and unsanded veneers can easily be pressed into high-quality boards.
DIEFFENBACHER LVL technology enables board thicknesses of up to 120 mm and allows MUF adhesives to be used in the top veneer overlapping area. Boards with these properties have been produced in practice at DIEFFENBACHER plants at Nelson Pine in New Zealand and at Pacific Woodtech in the U.S.
“We knew of DIEFFENBACHER’s previous LVL projects. These excellent references are among the reasons that we ultimately chose DIEFFENBACHER as our supplier,” said Grady Mulbery upon signing a contract with DIEFFENBACHER in 2017. The Roseburg line in Chester is DIEFFENBACHER’s eighth LVL project with a continuous press. More than 80% of the world’s continuous LVL production occurs in plants using DIEFFENBACHER equipment.