LVL Handbook EUROPE

1. LVL AS A CONSTRUCTIONMATERIAL

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 debark-

er 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 qual-

ities are obtained from the outermost layers of the wood dur-

ing peeling.

The conditioning increases the internal temperature of the

blocks andmakes the wood softer for peeling. In northern win-

ter 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 recov-

er the maximum amount of veneer from the block, the block

is optimally aligned between the lathe spindles using high pre-

cision laser measurement.

In the lathe, the peeler block is rotated between the spin-

dles at a constant speed while the knife carriage moves toward

the block core. For LVL production, the typical nominal thick-

ness 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