Effect of latewood proportion on mechanical properties of Finnish pine wood modified with compression drying.

摘要

Mechanical and structural changes caused by compression drying of Finnish pine wood (Pinus sylvestris L.) were studied. Elastic modulus, yield stress, Brinell hardness, and latewood proportion were determined for eight boards. Radial compression during the drying process was found to increase latewood proportion by approximately 18% as a result of earlywood deformation. Elastic modulus and yield stress were higher in the radial direction (128 and 2.25 MPa) than in the tangential direction (99 and 2.09 MPa) for green samples, whereas they were higher in the tangential (288 and 4.74 MPa) compared with the radial direction (201 and 3.59 MPa) for dried specimens. Elastic modulus, yield stress, and Brinell hardness correlated significantly (R²=0.65, p<0.05; R²=0.73, p<0.01; R²=0.69, p<0.01, respectively) with latewood proportion. Compression drying enhanced the tangential mechanical properties and surface hardness of Finnish pine wood as a result of increased latewood-to-earlywood ratio.