Name: lumber cutting methods
Uploaded: 2024-09-12T16:16:32.000Z
Duration: 1 min 19 s
Channel: JoVE

Lange, rechteckige Holzstücke, die im Bauwesen verwendet werden, werden als Schnittholz bezeichnet.
Stämme, die von Bäumen geerntet werden, werden entrindet und wiederholt durch eine automatisierte Säge geführt.
Jedes Mal, wenn der Stamm geschnitten wird, werden die Platten per Förderband zu kleineren Sägen transportiert. Hier werden die Platten zu kantigem Schnittholz in den gewünschten Breiten geschnitten.
In diesem Stadium haben die geschnittenen Teile raue Oberflächen, und ihre Abmessungen können von einem Ende zum anderen leicht variieren.
Das Schnittholz wird entweder durch Flach- oder Viertelsägen gewonnen. Schnittholz stellt die Jahresringe von Bäumen flach auf der breiteren Fläche des Brettes dar und wird typischerweise als Konstruktionsholz verwendet.
Bei Viertelschnittholz richten sich die Jahresringe bei Nadelhölzern bei etwa 45 Grad oder mehr und bei Laubhölzern bei 60 Grad oder mehr zur breiteren Fläche des Bretts aus. Viertelgesägtes Nadelholz wird für Fußböden, Verkleidungen und Verkleidungen verwendet.
Das Riftsägen wird auch für Laubhölzer verwendet, wobei die Jahresringe aus riftgesägtem Laubholz in einem Winkel von 30 bis 60 Grad zur breiten Oberfläche des Bretts ausgerichtet sind und dort eingesetzt werden, wo Aussehen und Haltbarkeit entscheidend sind.

schnittholz

Schnittholz wird aus Stämmen gewonnen, die geerntet, entrindet und zu langen Stücken mit rechteckigem Querschnitt verarbeitet werden. Die Umwandlung von Stämmen in Schnittholz umfasst mehrere Schritte, beginnend mit einer automatischen Säge, die den Stamm in Platten schneidet. Diese Platten werden dann über ein Förderband zu kleineren Sägen transportiert, wo sie in quadratische Stücke bestimmter Breiten geschnitten werden.

Anfangs sind die Oberflächen dieser Schnittholzstücke rau und ihre Abmessungen können von einem Ende zum anderen leicht variieren. Das Schnittverfahren des Holzes beeinflusst die Eigenschaften und Anwendungen des Schnittholzes erheblich. Schnittholz wird auf drei Arten geschnitten: Längsschnitt, Viertelschnitt oder Spaltschnitt.

Längsschnittholz weist Wachstumsringe auf der breiteren Seite des Bretts auf, die fast flach sind, und wird aufgrund seiner Produktionseffizienz und Kosteneffizienz häufig für strukturelle Anwendungen verwendet. Viertelgeschnittenes Schnittholz, bei dem die Wachstumsringe bei Nadelhölzern etwa 45 Grad und bei Laubhölzern 60 Grad zur breiteren Seite des Bretts ausgerichtet sind, wird aufgrund seiner verbesserten Stabilität und Optik bevorzugt für Produkte wie Fußböden, Zierleisten und Verkleidungen verwendet. Beim Radialschnitt, das hauptsächlich bei Laubhölzern angewendet wird, werden die Wachstumsringe in einem Winkel von 30 bis 60 Grad ausgerichtet, was die Ästhetik und Haltbarkeit optimiert und es ideal für hochwertige Möbel und dekorative Anwendungen macht. Jedes Schnittverfahren bietet unterschiedliche Vorteile und erfüllt unterschiedliche Anforderungen in der Bau- und Holzverarbeitungsbranche.

Schnittholz

Lange, rechteckige Holzstücke, die im Bauwesen verwendet werden, werden als Schnittholz bezeichnet.
Stämme, die von Bäumen geerntet werden, werden entrindet und wiederholt durch eine automatisierte ...

Education

Lehre

JoVE Core

Civil Engineering

Bauingenieurwesen

Unit 1

Einheit 1

Wood

Holz

KEY TERMS AND CONCEPTS

ZENTRALE BEGRIFFE UND KONZEPTE

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.

Lumber is cut in three main ways: plainsawing, quartersawing, and riftsawing. Plainsawn lumber has growth rings that lie nearly flat on the board’s wider face. It is often used for structural applications because it is efficient to produce and cost-effective.

Quartersawn lumber places the growth rings at about 45 degrees in softwoods and 60 degrees in hardwoods to the wider face of the board. It is often chosen for flooring, trim, and siding because it is more stable and has a better appearance. Riftsawing is used mainly for hardwoods. It sets the growth rings at a 30 to 60-degree angle and is well suited for high-quality furnishings and decorative uses because it improves durability and visual appeal.

Lumber Cutting Methods

introduction to wood

Wood Structure and Uses in Building

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...

softwoods and hardwoods

Wood Grain in Softwoods and Hardwoods

Softwoods and hardwoods come from different kinds of trees, and their leaf structures and cell makeup help explain how they are used. Softwoods come from cone-bearing trees with needle-like leaves. Hardwoods usually come from trees that shed broad leaves seasonally. Softwoods are made mostly of long cells called tracheids and a smaller number of rays, which are radial cells. This simpler structure gives softwoods a rougher grain. Because of this, they are often used in construction for...

lumber

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...

structural properties and dimensions of lumber

structural-properties-and-dimensions-of-lumber

Wood Strength Tests and Lumber Sizes

Wood strength depends on how its fibers are aligned along the length of the tree. This alignment gives wood much greater tensile strength along the grain than across it, sometimes up to twenty times higher. Wood also tends to perform better under compression than under tension. Fiber length varies by wood type. Hardwoods have fibers about one twenty-fifth of an inch long. Softwoods have longer fibers that range from one-eighth to one-third of an inch. Laboratory tests help measure how wood...

seasoning of wood

Wood Drying for Stronger Construction

Seasoning of wood is the drying process used to lower and stabilize moisture content before wood is used in construction. Fresh wood can swell when it takes in moisture and contract as it dries. Seasoning helps reduce that movement so the wood stays more stable after it is built into a structure. The main goal is to reach equilibrium moisture content. This is the point where the wood’s moisture level matches the moisture in the surrounding environment. When wood is seasoned properly, it is...

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

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...

wood fasteners

Wood Fastener Types and Uses

Wood fasteners connect parts of a wood structure and help keep members in place. The strength of the connection depends mainly on direct bearing between the wood members. Different fasteners are chosen for different jobs and structural needs. Nails are the most common wood fasteners. They are sharp-pointed metal pins that are driven into wood with a hammer or a mechanical nail gun. Nails come in many diameters, head styles, and lengths. Nailing methods also matter. Face nailing places the...

veneer

How Veneer Is Cut and Used

Veneer is a thin sheet of wood that is usually about one-eighth of an inch thick or less. It is made to show the look of wood while using timber more efficiently. Veneer is common in furniture and other finished wood products. One common way to make veneer is rotary cutting. In this method, a log is mounted in a large lathe and spun against a knife edge. As the knife moves deeper into the turning log, it peels off a continuous strip of wood. This creates rotary-cut veneer. Other veneer...

wood products

Engineered Wood Products in Construction

Engineered wood products are made from wood strands, veneers, lumber, and even waste wood shreds. They are used in both structural and nonstructural building applications. These materials are designed to improve strength, durability, and versatility in modern construction. Glue-laminated wood, or glulam, is made by bonding several smaller pieces of dimensional lumber with adhesive. Cross-laminated timber uses solid lumber panels with layers placed so the grain direction alternates. This layer...

wood panel products

Types of Wood Panels in Construction

Wood panels are common construction materials used for flooring, siding, and roofing. They usually come in standard 4-foot by 8-foot sheets. Their thickness can range from one-quarter of an inch to one and one-eighth inches. Plywood is one of the most familiar wood panels. It is made by gluing thin wood veneers, or layers, under pressure. The outer veneer grain runs lengthwise, while the inner layers run widthwise. Plywood also has an odd number of layers, which helps keep the panel...

key terms and concepts

Learn how logs become lumber and how plainsawing, quartersawing, and riftsawing change the wood’s look, stability, and uses in construction and furniture.

Lumber Cutting Methods | 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

Lumber Cutting Methods

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