Abstract

Root cause and vibration analysis is applied to a veneer peeling lathe to increase its efficiency and reduce wood waste. Excessive veneer thickness variations, repetitive damage of machine component and high vibration levels of the lathe are identified as interrelated issues. A root cause analysis is conducted to finally select both design and operating factors, which were then investigated to quantify their effects on the vibratory lathe response and process efficiency. On-site vibration measurements for different operating speeds, cutting tool conditions and log sizes are analyzed from RMS, kurtosis and crest factors for a 95% confidence interval. Based on the statistical significance, the effect of the operating conditions on the vibration energy level and impulsivity of the lathe is obtained. The analysis confirms that (1) the vibration level of the peeling process is significantly affected by the operating speed and cutting tool condition; (2) the signal impulsivity characterized by kurtosis varies with the process speed; and (3) the log size affects process efficiency. In addition, finite element modal analysis is applied to the lathe carriage structure to identify whether a transient resonance occurs during the peeling process. Finally, the study recommends the optimal lathe operating speed found for reducing vibration levels and incomplete log peeling.