Simulated Sawing with a Chipping Headrig

Southern pine sawlogs were studied to determine the location of defects and the relationship of defects to the grade and value of lumber produced by a chipping headrig. Ten 13-inch logs were cut into 1-inch discs, and the location of internal defects was recorded. A computer was used to theoretically saw the logs into lumber in a manner simulating a chipping headrig. Each log was sawn to yield both dimension lumber and boards, and to yield only dimension lumber. In addition, each log was theoretically sawn over again at different circumferential log positions until it was processed in every possible multiple of 10-degree rotation from the original sawing plane. Results showed that the value of lumber was affected by both sawing pattern and circumferential log position. Production of boards from the side lumber was more profitable than producing all dimension lumber. All logs had an optimum position that produced the highest grade and hence, maximum value lumber. Differences in value between the best and poorest log position were not large in high grade logs, but the value of lumber produced from low grade logs varied by 43 percent from the best to the worst log position. Suggested methods for relating exterior log appearance to optimum log rotation were developed.

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