Some fir pile processing companies have troubles with the inability to use defective fir piles. Some manufacturers even sell defective fir piles as scrap fir piles. In fact, the use value of defective fir piles is still very high. Any kind of fir pile defects have a great impact on fir piles. The product grade has a certain impact, causing the fir piles to lose their original value. The processing affects the economic yield of the fir piles. However, reasonable application can greatly reduce the negative impact of defects in the fir piles, and sometimes improve the fir piles. application and economic value.

(1) Setsuko

1. The definition and classification of knots.

(1) Definition: During the growth of trees, the bases of living branches or dead branches hidden inside the trunk or main branches are called knots.

(2) Classification: The shapes, materials and distribution of knots are diverse. Because the classification characteristics are different, there are many classification methods. Therefore, the same knot can have several types according to different classification methods. A name. According to the connection between the knots and the 4-week fir wood piles, they can be divided into living knots and dead knots. According to the material of the knots, they can be divided into healthy knots, rotten knots and leaky knots. According to the cross-sectional shape of the knots, they can be divided into There are three types of nodes: round nodes (including oval nodes), strip nodes and palmate nodes. According to the distribution of nodes on the trunk, they can be divided into scattered nodes, group nodes, whorled nodes and forked nodes.

2. The influence of knots on processing and application. It is a normal phenomenon for fir wood piles to have knots. Except for logs used directly for pit wood, electric poles, pile wood, etc., other wood types are regarded as a defect. Moreover, knots The knot is one of the important factors in evaluating the grade of fir piles. According to statistics, 70%-90% of the grading of fir piles is determined by knots. It can be seen that knots have a great influence on the material.

The influence of knots on the quality of fir piles mainly depends on the type, size, and horizontal distribution of the knots and the use of the fir piles. Ordinary living knots have little impact, followed by dead knots, and missing knots have a greater impact. Round knots have a greater impact on the quality of fir piles. Small, strip-shaped segments and palmate-shaped segments have a greater impact. In summary, the main manifestations are as follows:

(1) The knot destroys the uniformity and integrity of the fir pile structure, affects the fiber arrangement direction of the fir pile around the knot, and forms a local curved or interlaced texture. The fir pile has tensile strength, bending strength, and static bending strength along the grain. Reducing is not conducive to the effective use of fir piles.

(2) Knots affect the yield rate of sawn timber and veneer and the quality of scrap products. The workload of veneer repair increases.

(3) Knots affect the processing of fir wood piles, increasing the cutting resistance of the tool and affecting the processing quality. When sawing wood, the feeding speed must be slowed down when encountering knots, otherwise the saw teeth or saw blades will be damaged. In rotary cutting And in planing, the cutting tool will quickly become dull and the cutting edge will be damaged.