1. LVL AS A CONSTRUCTION MATERIAL Figure 1.25. Peeler blocks being lifted from a conditioning chamber. Figure1.26. XY centring device with laser scanning Figure1.27. Peeling method The logs are cut to the required peeler block lengths on an automatic saw line and transferred to the debarker. The debarker removes the bark down to the cambium so that the blocks are free of bark. During debarking, damage to the peeler block surface is carefully avoided, as the most valuable veneer qualities are obtained from the outermost layers of the wood during peeling. The conditioning increases the internal temperature of the blocks and makes the wood softer for peeling. In northern winter conditions the logs are thawed by soaking them in covered and heated conditioning chambers. 1.6.2 Blocks to veneer A jack-ladder lifts the blocks one by one to the charger for XY centering. The block charger plays a key role in optimizing raw material utilization and the value of the veneer yield. To recover the maximum amount of veneer from the block, the block is optimally aligned between the lathe spindles using high precision laser measurement. In the lathe, the peeler block is rotated between the spindles at a constant speed while the knife carriage moves toward the block core. For LVL production, the typical nominal thickness for softwood veneer is 3 mm. According to EN14374, the maximum thickness of veneers in structural LVL is 6 mm. The veneer is peeled through the gap between the peeler knife and the overhead nose bar. The knife gap is smaller than the veneer thickness to ensure sufficient compression and high-quality veneer. LVL Handbook Europe 27
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