Posted 19 Dec 2010 21:53
A variety of wood defects, definitions, and the impact of material defects in the name of the timber and definitions, applicable to all of China coniferous wood roundwood, sawn timber and veneer products. 1, sub-section included in the trunk or main branch of the branches of the middle part of the timber as knots. A: Easter: Live from the trees branches are formed. Setsuko closely connected with the surrounding wood raw, hard texture, structure normal. Death: the dead branches from the trees formed. Setsuko closely with the surrounding wood from most or all, hard or soft, sometimes off in the plate to form cavities. B: sound section: material well-knot, the Department no signs of decay. Decadent sections: sub-section itself is ****, but did not penetrate inside the trunk, knots around the material is still intact. Drain sections: sub-section itself is not only ****, but deep inside the trunk, causing the internal decay of wood. Therefore, the internal decay leak Li Changcheng to the external characteristics of the trunk. C: circular section (including the oval section - section sub-section of the long diameter and short diameter ratio of less than 3), sub-section were round or oval-shaped, multi-surface performance in the round timber and sawn timber on the tangential section . strip sections: the diameter of the surface of the elongated strips of lumber: a long longitudinal section of knot diameter and short diameter or length of more than or equal to 3 or 3, more than longitudinal section of the Health and cut loose from. palmate Festival: presented on the lumber Radial section, arranged into two symmetrical strip. Multi-longitudinal section cut from the whorl is made. D: scattered sections: the trunk into a single place in the loose, this sub-section of the most common. Whorl section: round shape around the tree trunk into arranged within a short distance in the number of knots are more common in pine, spruce and other species of the genus. Qun sections: section two or more sub-clustered together, within a short distance larger number of knots. Bifurcated sections: the first because of the bifurcation of the slightly acute angle with the main longitudinal axis, and formation. Material on the circle round was extremely long, in the lumber and veneer, but also a long oval or ribbon. E: wood surface sections: sub-section width of material exposed in the surface (vertical surface of four square refers.) Wood sections: section exposed in the narrow sub-surface material above. Wood edge sections: section on child exposed in the edges. Through section: the relative surface of the wood surface or adjacent materials through the knots. Sub-section of the material: Wood Structure Section ruin the uniformity and integrity, not only affects the surface appearance of wood and processing properties, more importantly, is to reduce some of the strength of wood is not conducive to the effective use of wood. In particular the use of load-bearing structure such as wood, with knots on the size and number of closely related. The extent of use of sub-section is mainly based on the material sub-section, location, size, intensity and wood uses. Knot tensile strength parallel to grain of the greatest impact, followed by the bending strength, especially in sub-section of the edge components the most obvious; little effect on compressive strength parallel to grain; In contrast, sub-section can improve the anti-stripes compression strength parallel to grain.