An investigation into the dynamics of RF LVL pressing

Abstract

The dynamics of radio frequency (RF) laminated veneer lumber (LVL) pressing are explored for the purpose of optimizing this process. The RF LVL press at the Albany Trus Joist plant is the focus of this investigation. The investigation first focuses on bond strength development characteristics of the Georgia Pacific adhesive formula in use at the subject plant. The automated bonding evaluation system (ABES) developed by Dr. P. E. Humphrey is used in this study to determine the bond strength development rate of this adhesive. The second focus of the investigation is the development of a spreadsheet based, deterministic model of temperature, bond strength and vapor pressure development within the LVL veneer assembly during the pressing cycle. This tool may be used to conduct sensitivity studies to investigate changes that may effect the efficiency of the RF LVL pressing processing. The final focus of the investigation is capturing actual data from the subject press during operation in order to evaluate the deterministic model. The goal of this investigation is to provide information and tools to maximize the productivity of the RF LVL pressing process. The study concludes that the deterministic model usefully predicts temperature and bond strength development within the veneer assembly over the course of the RF pressing cycle. It demonstrates that a spreadsheet format may be successfully employed for one dimensional deterministic modeling of the RF LVL pressing process.