| 摘要 |
PURPOSE:To enable the easy execution of the inspection for back cracking of veneers, by coating a coloring agent on the back cracked surface of a veneer to infiltrate the same in the back cracked parts, then planing the veneer thinly prescribed times. CONSTITUTION:A dye soln. of a primary color having poor dyeability is first coated on the back cracked surface of a veneer 4 and is dried. The back cracked surface of the veneer is then planed 2-3 times at about 0.08-0.10mm. by using an ultra-finishing plane and the number of the linear back cracked parts 5 appeared after the planing per unit length A of the veneer 4 is counted and is taken as the number of back cracks. Also, the back cracked surface of the veneer 4 is planed with said plane until the back cracked parts 5 appearing like dark lines on the planed surface counts to 10 pieces per each 25cm. Thereafter, the planing is ceased when the parts 5 appearing on the planed surface counts 4-6 pieces, and the thickness in this stage is measured. A ratio to the original thickness of the veneer 4 is determined from the thickness obtd. in such a way to express the rate of back cracking. The inspection even by unskilled persons is thus made possible, and the time for the inspection is considerably reduced. |
