Development of a new incising technology for plywood/LVL production. Part 1. Incising at the lathe and its effect on veneer quality and recovery

The development of a new method to incise veneer at the lathe is discussed in this paper. Laboratory and mill trials were conducted to evaluate its effect on veneer quality and recovery. Results from these trials showed that incising veneer at the lathe can significantly improve veneer quality and recovery. Veneer is much flatter when peeled with a combination of incising and overdriving during peeling. Species has a very strong effect on veneer flatness, especially spruce and Douglas-fir. Bar overdrive seems to be equally as important as incising. For the mini-lathe with which the tests were carried out, a 100.5 percent overdrive yields the flattest veneer. Peeling speed and log conditioning have much less effect on veneer flatness than species and overdrive. Faster peeling speed and lower conditioning temperature favor veneer flatness. According to the laboratory tests and mill trial, veneer recovery can be increased substantially by about 5 percent from veneer stretching and flattening and reduction of spin-outs. The incising technology has now been implemented in 10 plywood mills in North America, particularly in the softwood plywood mills that use a big roller bar lathe, because an incisor bar can be easily retrofitted.

You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member