Influence of vibration coupling between bandsaw frame and feed-carriage system on sawdust spillage and surface quality of workpiece during sawing

Productivity, surface quality, and recovery are three parameters that compete for attention during lumber production. The well known phenomenon of improved surface quality with decreasing workpiece feed rate has been reported by several researchers. This paper reports on experimental results from the relationship between workpiece feed rate or bite per tooth and the surface roughness of Japanese Sugi (Cryptomeria japonica) using a bandsaw machine whose feed-carriage is coupled to the bandsaw frame. The volume of sawdust produced during sawing was determined using an electronic balance. Equation was developed to determine the kerf-losses. It was observed that as the workpiece feed rate increased, or as the bite per tooth increased, the saw blade vibration decreased and the volume of sawdust also decreased contrary to expected results. Furthermore it was observed that with increasing workpiece feed rate the surface roughness decreased contrary to expected results. On the other hand, when the carriage feed rate increased the saw blade deviation also increased as expected. The research findings clearly suggest that when there is vibration coupling between the feed-carriage and the entire bandsaw frame, the amplitude of the saw blade vibration and the surface roughness decrease as the bite per tooth increases. Thus the bandsaw machine whose frame is coupled to the feed-carriage is a promising technique for increasing lumber recovery and improving upon surface quality.