Tool Forces and Chip Formation In Orthogonal Cutting Of Loblolly Pine

Abstract

Specimens of earlywood and latewood of Pinus taeda L. were excised so that length along the grain was 3 inches and thickness was 0.1 inch. These specimens were cut orthogonally-as with a carpenter's plane-in the three major directions. Cutting velocity was 2 inches per minute. When cutting was in the planing (90-O) direction, thin chips, intermediate to high moisture content, rake angles of 5 and 15^o favored formation of the Franz Type II chip and accompanying good surfaces. In the 0-90 direction, a knife with 70^o rake angle cut the best veneer; wood cut saturated yielded the highest proportion of continuous veneer, although saturatedearlywood developed some compression tearing. When cutting was across the grain (90-90 direction), McKenzie Type I chips were formed and the best surfaces were achieved with a knife having 45^o rake angle cutting saturated wood; earlywood was more difficult to surface smoothly than latewood. For each cutting direction, regression equations were developed to state average cutting forces (normal and parallel) in terms of rake angle, depth of cut, specific gravity, and moisture content.

Citation

Woodson, George E.; Koch, Peter. 1970. Tool Forces and Chip Formation In Orthogonal Cutting Of Loblolly Pine. Res. Pap. SO-52. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station. 29 p.