Name: common wood flaws in lumber
Uploaded: 2024-09-12T16:16:32.000Z
Duration: 1 min 23 s
Channel: JoVE

Os defeitos de crescimento na madeira incluem nós, que são formados onde os galhos se conectam ao tronco da árvore, nós que resultam da queda de nós soltos, decomposição e danos causados por insetos.
Tremores são pequenas fraturas ao longo ou através dos anéis anuais e são defeitos comuns da madeira.
Wane refere-se à falta de madeira ou à presença de casca ao longo da borda de uma tábua.
As verificações são as rachaduras radiais que se desenvolvem nas toras e são falhas de fabricação que ocorrem devido ao encolhimento circunferencial que leva à contração durante o processo de tempero.
Warp refere-se a qualquer desvio de uma superfície plana e precisa na placa. Os tipos de urdidura incluem curvar-se, curvar-se, torcer e escavar na madeira.
O faveolamento refere-se a rachaduras internas em uma placa que ocorrem devido ao tempero inadequado.
O grão rasgado resulta da madeira sendo lascada ou retirada da superfície da placa devido ao corte ou aplainamento. Esses defeitos afetam a resistência da madeira.
Manchas superficiais podem aparecer na madeira depois de processada em madeira serrada. Essas manchas marrons, verdes ou azuis geralmente afetam a aparência, mas não a resistência da madeira.

defeitos na madeira

Lumber Defects

Os defeitos na madeira, que podem afetar tanto a aparência quanto a integridade estrutural da madeira, incluem uma variedade de falhas de crescimento e fabricação. Defeitos de crescimento, como nós e buracos, ocorrem onde os galhos antes estavam presos ao tronco da árvore, com buracos se formando quando esses nós caem. Outros defeitos naturais incluem deterioração e danos causados ​​por insetos, que comprometem a resistência e durabilidade da madeira.

Shakes são pequenas fraturas que correm ao longo ou através dos anéis anuais da madeira, enquanto o wane é caracterizado pela falta de madeira ou pela presença de casca ao longo da borda de uma tábua, normalmente resultante da maneira como a madeira é cortada. Checks são rachaduras radiais dentro da madeira, aparecendo conforme a madeira seca e encolhe circunferencialmente durante o processo de cura.

A deformação é um desvio da superfície plana da madeira e pode se manifestar como encurvamento, arqueamento, torção ou curvatura, cada um afetando a usabilidade da madeira. Honeycombing refere-se a rachaduras internas causadas por cura inadequada, o que pode enfraquecer a madeira internamente.

Grão rasgado é outro defeito que ocorre durante o processo de corte ou aplainamento, onde a madeira lasca, resultando em uma superfície áspera. Por fim, manchas superficiais como descolorações marrons, verdes ou azuis podem se desenvolver após o processamento. Essas manchas geralmente afetam apenas a aparência da madeira e não sua resistência.

Entender esses defeitos é crucial para gerenciar a qualidade da madeira e garantir que a madeira atenda aos padrões necessários para usos de construção e fabricação.

Defeitos na Madeira

Os defeitos de crescimento na madeira incluem nós, que são formados onde os galhos se conectam ao tronco da árvore, nós que resultam da queda de nós soltos, decomposição ...

Education

JoVE Core

Civil Engineering

Engenharia Civil

Unit 1

Unidade 1

Wood

Madeira

KEY TERMS AND CONCEPTS

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common wood flaws in lumber

Lumber defects are flaws in wood that can change both its appearance and its strength. These defects come from tree growth and from the way lumber is processed. Knowing the main defects helps explain why some boards are better for construction and manufacturing than others.

Some defects begin in the tree itself. Knots form where branches were once attached to the trunk, and knotholes appear when those knots fall out. Decay and insect damage are also natural defects that can weaken wood and reduce its durability.

Other defects come from splitting, cutting, or drying the lumber. Shakes are small fractures that run along or across the annual rings. Wane is the missing wood or bark left along a board edge after cutting. Checks are radial cracks that form as wood dries and shrinks during seasoning, and honeycombing is a set of internal cracks caused by improper seasoning.

Warping changes the flat shape of a board. It can show up as crooking, bowing, twisting, or cupping, and each form can make the lumber harder to use. Torn grain is another processing defect, where the wood chips away during cutting or planing and leaves a rough surface. Surface stains, such as brown, green, or blue discoloration, may also appear after processing. These stains usually affect appearance more than strength.

Common Wood Flaws in Lumber

introduction to wood

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Wood is a construction material made from trees. A tree trunk has several layers. The outside is a protective layer of dead bark. Under that is living bark, then the cambium, then sapwood. As sapwood matures, it becomes heartwood. The pith sits at the center of the trunk. The age of a tree can be read from its growth rings. These rings are concentric bands seen in a trunk cross-section. Wood strength also depends on grain. Grain refers to elongated, tubular cells that run along the length of...

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lumber

Lumber Cutting Methods

Lumber is made from logs that are harvested, debarked, and processed into long pieces with a rectangular cross-section. The process starts when an automated saw slices a log into slabs. Those slabs then move on a conveyor belt to smaller saws, where they are cut into square-edged pieces of specific widths. Freshly cut lumber usually has rough surfaces. Its dimensions may also vary slightly from one end to the other. The way wood is cut affects both the lumber’s appearance and how it is used. <br...

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wood surfacing

Wood Surfacing for Smooth, Safe Lumber

Wood surfacing smooths lumber, improves its size accuracy, and makes it safer to handle. It is a key finishing step in woodworking and construction. The process also helps correct small distortions that can form as wood dries. Before surfacing, the wood may be sized slightly larger to account for shrinkage during seasoning, which is the drying stage. A plane, a tool with rotating blades, is used to remove material and smooth the surface. The same tool can also round the edges a little, which...

lumber defects

Lumber defects are flaws in wood that can change both its appearance and its strength. These defects come from tree growth and from the way lumber is processed. Knowing the main defects helps explain why some boards are better for construction and manufacturing than others. Some defects begin in the tree itself. Knots form where branches were once attached to the trunk, and knotholes appear when those knots fall out. Decay and insect damage are also natural defects that can weaken wood and...

wood fasteners

Wood Fastener Types and Uses

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key terms and concepts

Learn the main lumber defects found in wood, from knots and decay to warping, checks, and stains, and how they affect strength and appearance.

Common Wood Flaws in Lumber | JoVE K12

JoVE Core Civil Engineering provides a foundational exploration of essential construction materials in civil engineering, focusing on bricks, stones, steel, wood, and concrete through easy-to-understand animated videos. This collection covers the properties, manufacturing processes, and practical applications of these materials. Additionally, the accompanied science-in-action videos demonstrate the research experiments performed in laboratories.

civil engineering

Common Wood Flaws in Lumber

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