05/03/2024 11:48

What is sliced veneer? Technical requirements for sliced veneer in Vietnam under TCVN 4358:2021

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What is sliced veneer? What are the technical requirements for sliced veneer in Vietnam under TCVN 4358:2021? _Nguyen Binh (Ca Mau)

Hello, Lawnet would like to answer as follows:

1. What is sliced veneer?

According to the regulations in TCVN 4358:2021, sliced veneer is defined as follows:

Sliced veneer: It is a thin sheet of wood created by the slicing method.

In addition, sliced veneer produced by different methods will have specific names:

Radial sliced veneer:

- Radial sliced veneer is created by slicing parallel to the longitudinal axis of the tree and perpendicular to the growth rings.

- In terms of the growth rings, the lines on the longitudinal cut of the wood grain are in the form of parallel straight lines.

- In terms of the wood rays, on at least 3/4 of the surface area of the sliced veneer, the wood rays are in the form of darker or lighter streaks compared to the surrounding wood and perpendicular to the longitudinal axis of the wood grain.

Tangential sliced veneer:

- Tangential sliced veneer is created by slicing parallel to the longitudinal axis of the tree and tangential to the growth rings.

- In terms of the growth rings, the lines on the surface of the sliced veneer are in the form of V-shapes or curves.

- In terms of the wood rays, on the surface of the sliced veneer, the wood rays are in the form of darker or lighter streaks compared to the surrounding wood and aligned along the longitudinal axis of the wood grain.

Semi-radial sliced veneer:

- In terms of the growth rings, on the surface of the sliced veneer, at least 3/4 of the surface area consists of parallel straight lines.

- In terms of the wood rays, on the surface of the sliced veneer, at least 1/2 of the surface area consists of wood rays in the form of darker or lighter streaks compared to the surrounding wood, inclined or aligned with the longitudinal axis of the wood grain.

2. What are the technical requirements for sliced veneer in Vietnam under TCVN 4358:2021?

According to the regulations in TCVN 4358:2021, the technical requirements for sliced veneer are as follows:

Technical requirements for dimensions and dimensional tolerances:

The dimensions and dimensional tolerances of sliced veneer must comply with the following regulations:

Veneer size	Size	Tolerances
	< 0.20	± 0.02
	0.20 ÷ 0.50	± 0.03
1. Thickness, mm	0.51 ÷ 1.00	± 0.04
	1.01 ÷ 2.00	± 0.06
	> 2	± 0.08
2. Width, mm	≥ 60	+5
2. Width, mm	≥ 60	0
3. Length, mm	≥ 500	+ 10
3. Length, mm	(Advanced rate (+50) mm)	0
Note: The sizes listed are commonly used sizes. Depending on the agreement between the two parties and usage requirements, many different sizes can be offered

Technical requirements for appearance quality in Vietnam

The external quality of sliced veneer is divided into 3 categories: standard grade, grade 1, and special grade. The external quality is defined as follows:

Criteria				Quality level
				Special		Type 1		Standards
1. Living eyes	Broadleaf wood	Largest eye diameter, mm		ten		20		Unlimited
	Coniferous wood			5		ten		20
2. Dead eyes, holes, sticky shells, plastic bags	Dead eyes, holes, shells, plastic bags	Total quantity per 1 meter length	Width ≤ 120 mm	0		first		2
			Width > 120 mm	0		2		3
	Half-living eyes	Largest eye diameter, mm		Not allowed		10 (less than 5 does not count)		20 (less than 5 does not count)
	Dead eyes, moth holes, holes	Largest eye diameter, mm		Not allowed		Not allowed		4 (less than 2 does not count)
	Stick to the shell	Maximum length, mm		Not allowed		Not allowed		20 (less than 10 does not count)
	Plastic bag					15 (less than 5 does not count)		30 (less than 10 does not count)
3. Uneven color, discoloration, discoloration		Color deviation		Very unclear		Unclear		Clear
4. Section		Observation, level		Not allowed		Not allowed		Not allowed
5. Cracks		Maximum crack width, mm		Private	Open	Private	< 0.2	Private	< 0.5
		Percentage of crack length compared to veneer length (%)		5	Not allowed	ten	5	15	ten
6. Knife marks, cuts, scratches		Feel with eyes and hands, level		Not allowed		Unclear		Small
7. Defects, damage to edges and corners				Not allowed within the tolerance size of the veneer
Note: 1. The color deviation of decorative veneer is determined through discussion between the two buyers and sellers. If it is necessary to determine, a colorimeter is used. Distinguish levels of color deviation as follows: Total color deviation <1.5: Very unclear; Total color deviation 1.5~3: Unclear; Total color deviation 3~6: Clear. 2. Depending on the agreement between the two buyers and sellers and usage requirements, defects other than those falling under the technical requirements on appearance quality may be allowed.

Technical requirements for the moisture content of sliced veneer:

Before being put into use, sliced veneer must have a moisture content of 8% - 16%.

Technical requirements for the surface roughness of sliced veneer:

Standard TCVN 4358:2021 uses parameters Ra and Rz to evaluate the surface roughness of sliced veneer. The requirements for surface roughness of sliced veneer are as follows:

Type of wood	Parameter value, µm
Type of wood	Average error R _a	Undulating height R _z
1. Circular broadleaf wood	≤ 30	≤ 250
2. Broadleaf and coniferous wood	≤ 20	≤ 150

More details can be found in TCVN 4358:2021.

- This English translation is for reference purposes only and not a definitive translation of the original Vietnamese texts;
- Articles may be compiled from a variety of sources;
- Applicable Terms may have expired at the time you are reading;
- If you have any questions about the copyright of the article, please contact us via email banquyen@lawnet.vn

Hua Le Huy

Key word: veneer | sliced veneer | in Vietnam | Vietnam |

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