Debarking (lumber)

Last updated
Debarker machine Debarker.jpg
Debarker machine
Manually decorticated trunk of a spruce as protection to bark beetles Fichtenstamm entrindet.jpg
Manually decorticated trunk of a spruce as protection to bark beetles

Debarking is the process of removing bark from wood. Traditional debarking is conducted in order to create a fence post or fence stake which would then go on to be pointed before being planted. [1] Debarking can occur naturally during powerful tornadoes. [2]

Contents

Process

Debarking generally involves the use of industrial machinery into which the log or stake is placed. [3] These machines can be either stationary or portable. Generally they are powered by hydraulic motors but can also be driven by a power take-off. The log or stake is then pressed against blades or knives which remove the bark while the log is turned to ensure the removal of bark from all around the log. Debarking can also take place by hand, although this can be very time consuming and may not be suitable for large volumes. [4]

Side-streams from debarking

Bark is the usual side-stream produced during log debarking. In several wood related industries, such as plywood, veneer and laminated veneer industries, the logs, before debarking them, are submerged in warm water to ease the debarking process [5] . The process conditions (temperature and time) depend on the country, company, wood species and their properties [5] [6] . In some countries, such as Finland, the water used in this process is discarded, but studies prove that it accumulates several valuable compounds, such as glucosides, proanthocyanidins and phenolics [7] . This water is a promising side-stream that should be further studied.

See also

Related Research Articles

<span class="mw-page-title-main">Adhesive</span> Non-metallic material used to bond various materials together

Adhesive, also known as glue, cement, mucilage, or paste, is any non-metallic substance applied to one or both surfaces of two separate items that binds them together and resists their separation.

<span class="mw-page-title-main">Wood</span> Fibrous material from trees or other plants

Wood is a structural tissue found in the stems and roots of trees and other woody plants. It is an organic material – a natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin that resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or more broadly to include the same type of tissue elsewhere, such as in the roots of trees or shrubs. In a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, woodchips, or fiber.

<span class="mw-page-title-main">Smoking (cooking)</span> Exposing food to smoke to flavor or preserve it

Smoking is the process of flavoring, browning, cooking, or preserving food by exposing it to smoke from burning or smoldering material, most often wood. Meat, fish, and lapsang souchong tea are often smoked.

<span class="mw-page-title-main">Tannin</span> Class of astringent, bitter plant polyphenolic chemical compounds

Tannins are a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and various other organic compounds including amino acids and alkaloids.

<span class="mw-page-title-main">Plywood</span> Manufactured wood panel made from thin sheets of wood veneer

Plywood is a composite material manufactured from thin layers, or "plies", of wood veneer that are glued together with adjacent layers, having both glued with each other at right angle. It is an engineered wood from the family of manufactured boards, which include plywood, medium-density fibreboard (MDF), oriented strand board (OSB), and particle board.

<span class="mw-page-title-main">Tanning (leather)</span> Process of treating animal skin to produce leather

Tanning, or hide tanning, is the process of treating skins and hides of animals to produce leather. A tannery is the place where the skins are processed.

<span class="mw-page-title-main">Lignin</span> Structural phenolic polymer in plant cell walls

Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily. Chemically, lignins are polymers made by cross-linking phenolic precursors.

<span class="mw-page-title-main">Medium-density fibreboard</span> Engineered wood product

Medium-density fibreboard (MDF) is an engineered wood product made by breaking down hardwood or softwood residuals into wood fibre, often in a defibrator, combining it with wax and a resin binder, and forming it into panels by applying high temperature and pressure. MDF is generally denser than plywood. It is made up of separated fibre but can be used as a building material similar in application to plywood. It is stronger and denser than particle board.

<span class="mw-page-title-main">Blanching (cooking)</span> Brief scalding of food in boiling water

Blanching is a cooking process in which a food, usually a vegetable or fruit, is scalded in boiling water, removed after a brief timed interval, and finally plunged into iced water or placed under cold running water to halt the cooking process. Blanching foods helps reduce quality loss over time. Blanching is often used as a treatment prior to freezing, dehydrating, or canning vegetables or fruits to deactivate enzymes, modify texture, remove the peel and wilt tissue. The inactivation of enzymes preserves colour, flavour, and nutritional value. The process has three stages: preheating, blanching, and cooling. The most common blanching methods for vegetables/fruits are hot water and steam, while cooling is either done using cold water or cool air. Other benefits of blanching include removing pesticide residues and decreasing microbial load. Drawbacks to the blanching process can include leaching of water-soluble and heat-sensitive nutrients and the production of effluent.

<span class="mw-page-title-main">Bark beetle</span> Subfamily of beetles

A bark beetle is the common name for the subfamily of beetles Scolytinae. Previously, this was considered a distinct family (Scolytidae), but is now understood to be a specialized clade of the "true weevil" family (Curculionidae). Although the term "bark beetle" refers to the fact that many species feed in the inner bark (phloem) layer of trees, the subfamily also has many species with other lifestyles, including some that bore into wood, feed in fruit and seeds, or tunnel into herbaceous plants. Well-known species are members of the type genus Scolytus, namely the European elm bark beetle S. multistriatus and the large elm bark beetle S. scolytus, which like the American elm bark beetle Hylurgopinus rufipes, transmit Dutch elm disease fungi (Ophiostoma). The mountain pine beetle Dendroctonus ponderosae, southern pine beetle Dendroctonus frontalis, and their near relatives are major pests of conifer forests in North America. A similarly aggressive species in Europe is the spruce ips Ips typographus. A tiny bark beetle, the coffee berry borer, Hypothenemus hampei is a major pest on coffee plantations around the world.

<span class="mw-page-title-main">Particle board</span> Glued wood product

Particle board, also known as particleboard or chipboard, is an engineered wood product, belonging to the wood-based panels, manufactured from wood chips and a synthetic, mostly formaldehyde based resin or other suitable binder, which is pressed under a hot press, batch- or continuous- type, and produced. Particle board is often confused with oriented strand board, a different type of fiberboard that uses machined wood flakes and offers more strength.

<i>Betula alleghaniensis</i> Species of flowering plant in the birch family Betulaceae

Betula alleghaniensis, the yellow birch, golden birch, or swamp birch, is a large tree and an important lumber species of birch native to northeastern North America. Its vernacular names refer to the golden color of the tree's bark. In the past its scientific name was Betula lutea, the yellow birch.

<span class="mw-page-title-main">Pulp mill</span> Facility which pulps wood or plant fibre

A pulp mill is a manufacturing facility that converts wood chips or other plant fiber sources into a thick fiber board which can be shipped to a paper mill for further processing. Pulp can be manufactured using mechanical, semi-chemical, or fully chemical methods. The finished product may be either bleached or non-bleached, depending on the customer requirements.

<span class="mw-page-title-main">Wood veneer</span> Thin slices of wood

In woodworking, veneer refers to thin slices of wood and sometimes bark that typically are glued onto core panels to produce flat panels such as doors, tops and panels for cabinets, parquet floors and parts of furniture. They are also used in marquetry. Plywood consists of three or more layers of veneer. Normally, each is glued with its grain at right angles to adjacent layers for strength. Veneer beading is a thin layer of decorative edging placed around objects, such as jewelry boxes. Veneer is also used to replace decorative papers in wood veneer high pressure laminate.

<span class="mw-page-title-main">Wood flooring</span> Product manufactured from timber that is designed for use as flooring

Wood flooring is any product manufactured from timber that is designed for use as flooring, either structural or aesthetic. Wood is a common choice as a flooring material and can come in various styles, colors, cuts, and species. Bamboo flooring is often considered a form of wood flooring, although it is made from bamboo rather than timber.

<span class="mw-page-title-main">Birch bark tar</span> Substance derived from birch tree bark

Birch bark tar is a substance that is synthesized by dry distillation of birch tree bark.

<span class="mw-page-title-main">European spruce bark beetle</span> Species of beetle

The European spruce bark beetle, is a species of beetle in the weevil subfamily Scolytinae, the bark beetles, and is found from Europe to Asia Minor and some parts of Africa.

A hydraulic debarker is a machine removing bark from wooden logs by the use of water under a pressure of 700 kilopascals or greater. Hydraulic debarking can reduce soil and rock content of bark, but may increase the water content. Debarking water may be recycled after effective settling, but suspended solids may increase wear on high-pressure pumps. Hydraulic debarking has declined where water quality problems have arisen.

Russia leather is a particular form of bark-tanned cow leather. It is distinguished from other types of leather by a processing step that takes place after tanning, where birch oil is worked into the rear face of the leather. This produces a leather that is hard-wearing, flexible and resistant to water. The oil impregnation also deters insect damage. This leather was a major export good from Russia in the 17th and 18th centuries because of its high quality, its usefulness for a range of purposes, and the difficulty of replicating its manufacture elsewhere. It was an important item of trade for the Muscovy Company. In German-speaking countries, this leather was also known by the name Juchten or Juften.

<span class="mw-page-title-main">Molded plywood</span>

Molded plywood is the term for two- or three-dimensionally shaped products from multiple veneer layers that are glued together through heat and pressure in a pressing tool. The veneer layers are arranged crosswise at an angle of 90 degrees. Molded wood is used for flat furniture components such as seats, backrests and seat shells. When the veneer layers are arranged in the same direction, it is called laminated wood. It is used for armrests and chair frames. After pressing, the blanks are processed mechanically. A particular feature is the ability to produce different variations of shapes from the blanks. Due to its immense strength and low weight, molded wood is particularly suitable for interior decoration, seating furniture, bed slats, skateboards and vehicle construction.

References

  1. Debarkers. Energy Online Expo.
  2. Adams, Dave K. (2007). The structural engineer's professional training manual. McGraw-Hill Professional. p. 193. ISBN   978-0-07-148107-6 . Retrieved 24 May 2011.
  3. Leavengood, Scott. "Western Juniper Debarking Project" (PDF). Oregon State University. Archived from the original (PDF) on August 19, 2011. Retrieved April 14, 2011.
  4. "Chapter 10 - Debarking". Wood Harvesting with Hand Tools - An Illustrated Training Manual. International Labor Organization. 1987. p. 128. ISBN   9221062171. OCLC   816745408.
  5. 1 2 Rohumaa, Anti; Yamamoto, Akio; Hunt, Christopher Glaab; Frihart, Charles Richard; Hughes, Mark; Kers, Jaan (2016-05-11). "Effect of Log Soaking and the Temperature of Peeling on the Properties of Rotary-Cut Birch (Betula pendula Roth) Veneer Bonded with Phenol-Formaldehyde Adhesive". BioResources. 11 (3). doi: 10.15376/biores.11.3.5829-5838 . ISSN   1930-2126.
  6. Dupleix, Anna; Denaud, Louis; Bléron, Laurent; Marchal, Rémy; Hughes, Mark (2013). "The effect of log heating temperature on the peeling process and veneer quality: beech, birch, and spruce case studies". European Journal of Wood and Wood Products. 71 (2): 163–171. doi:10.1007/s00107-012-0656-1.
  7. Barbero-López, Aitor; Vek, Viljem; Poljanšek, Ida; Virjamo, Virpi; López-Gómez, Yeray Manuel; Sainio, Tuomo; Humar, Miha; Oven, Primož; Haapala, Antti (2022-05-01). "Characterisation, Recovery and Activity of Hydrophobic Compounds in Norway Spruce Log Soaking Pit Water: Could they be Used in Wood Preservative Formulations?". Waste and Biomass Valorization. 13 (5): 2553–2564. doi: 10.1007/s12649-022-01676-2 . ISSN   1877-265X.