うらごけ材（テーパー材）の高歩留り・高品質単板切削を目指した針葉樹小径木用ベニヤレース（第2報）: 工場における歩留り向上率，目切れ角と単板品質，単板品質とLVLの性能

摘要

As the second report, it was continued that the effects of the taper cutting using veneer lathe (the cutting edge profile is parallel to the generating line of the log) on the veneer yield rates and on the veneer quality were compared to that of the common cutting (the cutting edge profile is parallel to the spindle axis of the lathe) and discussed to promote the good use of the small diameter softwoods in Japan.rnThe veneer yield rates of the taper cutting on the veneers which were produced by use of practical lathe were measured. And the yield rates were compared to that of the common cutting.rnThe influences of the sloping grain angle on the veneer quality were examined by means of small test pieces.rnFurthermore, laminated veneer lumber (LVL) was produced making use of the veneer which was peeled by the taper cutting of the small-sized lathe or by the common cutting, and the influences of veneer quality on the qualities of LVL were investigated. The results were as follows;rn1) In the experiment by the practical veneer lathe, the veneer yield rate of the taper cutting was higher than that of the common cutting. In addition, the long veneer without the break was obtained. But, when the veneer yield rates were compared in each raw log, it was at times that the yield rate of the common cutting was higher than the taper cutting.rn2) On the veneers which were cut from the small specimens, the bending strength and the Young's modulus decreased with the increase of the sloping grain angle, the surface roughness of the veneer surface became large, cutting force and thrust force became large.rn3) When it compared with the taper cutting and the common cutting, concerning the veneers which were peeled with the small size lathe, the sloping grain angle of the taper cutting veneer was smaller than the angle of the common cutting, veneer also the variation of the sloping grain angle was small in the taper cutting veneer.rnUsing the veneers which were peeled by the taper cutting and the common cutting, LVL were produced respectively. The bending properties (bending strength and Young's modulus) of LVL were compared. As a result, mean values by taper cutting were larger than that of the common cutting, also the variations were small.%1．目的 　前報に引き続き，国産針葉樹の有効利用を 進めるために，単板切削における中心定規切削（スピンドル軸と切れ刃線とが平行）に対する側面定規切削（切れ刃線が原木側面に平行）の単板歩留りと単板品質の向上の効果を確認することを目的とした。