Popular wood quality standards

Timber is generally divided into three categories: logs, boards, and beams. Round lumber refers to wood that has been felled, peeled, and processed to a specific length. A plank is a profile that is three times the width or more than three times the thickness. Rectangular lumber is a profile whose width is less than three times its thickness.

Standard classifications of tree species are classified and evaluated based on the quality, characteristics and uses of the wood. At present, the commonly used wood quality standards in my country generally include the following types:

1. Quality of Agreement

Wood grades are divided into Grade 1, Grade 2, Grade 3 and Grade 4. Grade 1 is the highest grade and Grade 4 is the lowest grade. In evaluating the quality of logs, factors such as log diameter, shape, bark, scales, wood chips, and log mortality are assessed. Pests and diseases, etc., are mainly taken into account.

2. Types of processed wood

The types of treated wood are divided into  Grade 1, Grade 2, Grade 3, and Grade 4. Grade 1 is the highest grade and Grade 4 is the lowest grade. Factors such as dryness of the wood, color, grain, cracks, defects, dimensional accuracy, etc. Cross-sectional shape and convenience Will be taken into account in evaluating wood quality.

3. Types of plywood

Plywood grades are divided into Grade A, Grade B, Grade C and Grade D. Grade A is the best grade and Grade D is the lowest grade. When evaluating the quality of plywood Factors such as surface smoothness, thickness, and uniformity of coating should be considered. Degree of defect and moisture content

Class A

1. Blade length must be 80% or more than 9 feet, 10% or more than 6 feet, and the rest should be 4 feet or more.

2. The width of the board must be greater than 8 inches and 80% of the width must be greater than 6 inches.

3. The pattern material must account for more than 70%, the grain pattern material must account for 30%, and the width must be more than 4 inches.

4. There should be no strong water ripples. and a small amount of water ripple greater than 20% is allowed.

5. The allowed material content is less than 10%. There are 2 black capsules per square meter, 5 mm long and no more than 2 mm wide. Black capsules with holes are not allowed.

6. Length of mineral wire less than 10 mm and less than 3 wires per square meter. A few knots (holes) are acceptable. A length of 9 inches can be less than 2 inches, but volume cannot be calculated. Sections should not Show clear knife marks and sections wider than 1 mm will not be accepted. Rough cutting is not allowed. (Pores are too large)

7. Curved and uneven boards are unacceptable. 20% light knots are accepted. Sliding knots should not be larger than 5 mm and not more than 3 per square meter. A white edge of 30% of the unfolded edge is acceptable. But the width of the edge should not exceed 20%.

Class B

Dead or rotten branches are not allowed. The length of the black watermark should be less than 20 mm and the width less than 5 mm. The diameter of the joint can be less than 30 mm.

The translucent crepe is less than 50 mm long and 5 mm wide, accounting for less than 20% of the veneer surface and is evenly distributed.

Class C

Dead branches are not allowed. rotting core material and corrosive water stains (Dark black water stains can cover up to 50% of the veneer surface.explain:

Class A veneer is generally used for transparent colored products such as panels, door panels, bed rails, etc. Class B veneer is used for other parts. of transparent colored products

1. The moisture content of wood veneer can be between 8% and 14%.

2. The veneer thickness tolerance is allowed within +0.1 and the veneer width tolerance is allowed within +10mm to 20mm.

4. Changing the artificial panel

The quality of synthetic fiberboard is divided into EO grade, E1 grade, E2 grade and F4 star. The EO value is the highest and the F4 star is the lowest when evaluating the quality of synthetic fiberboard. Plank factors such as formaldehyde emissions Core density Surface quality and size stability is a key consideration.

The above is the standard classification of wood types commonly used in my country. Sorting different types of wood It can effectively improve the use value and market competitiveness of wood.