We explain what wood is, what its qualities are and what its composition is like. Also, its general characteristics and what it is used for.
The wood trunk is made up of concentric and circular layers.
What is wood?
Wood is a natural, flexible and resistant material with which the different types of known trees generate their trunks, growing year after year through a system of concentric and circular layers. In fact, according to their production of wood in the trunk, trees are distinguished from herbaceous plants.
There are many types of wood, whose characteristics vary greatly. But in general terms, they are an extremely useful material for human beingswho has taken advantage of it since ancient times, and also for other life forms that feed on its accumulated biomass, either while the tree is alive or after its death and during its decomposition.
Wood is an abundant, renewable raw material, economical and easy to work withwhich processed in the correct way can resist the test of time for many years.
Timber it’s fuel And, furthermore, when used in construction it gives environments a feeling of warmth and ancestral protection, which is why it is a fundamental element in almost all human industries.
See also: Wool
Origin of wood
In prehistoric times, man has used wood to build tools.
As has been said, the wood has an organic originand first appeared on Earth millions of years ago, when plant life reigned over the continents.
Man has known it since its very origins as a species, since The first hominids were apes that descended from trees and they adapted to life on the plain.
Since then has used it to build toolsto light their fires and to build their houses.
Qualities of wood
The wood is receptive to varnishes and paints.
The qualities of wood They can vary greatly depending on the type and tree where it comes from, as well as the treatment that the wood has received.
However, it is broadly considered an elastic and resistant substance, which can be extremely dense or very light.
Wood is hygroscopic, capable of absorbing moisture from the air or even directly from water, and Its polarity makes it receptive to substances such as varnishes, glues or paints. It is a thermal and electrical insulator, which transmits sound very well.
Composition of wood
Timber It is composed of mostly cellulosea polysaccharide produced by plant life forms, together with other natural polymers such as lignin (25%), hemicellulose (25%) and other organic components such as resins, waxes and fats.
Its atomic composition is mostly carbon (50%) and oxygen (42%)along with hydrogen (6%) and nitrogen (2%).
Wood structure
Wood can be differentiated by cambium, sapwood and heartwood cells.
If a trunk is observed from its exterior to its core, the following structures will be found:
- External cortex. The outer layer of the tree, equivalent to the animal dermis, is made up of a rough cuticle of dead cells, which provide protection to the wood from the environment.
- Cambium. The layer following the bark, which is composed of phloem (the middle layer next to the bark) and xylem (the first layer of wood itself).
- Sapwood. This is the name given to the most recently formed wood through which most of the tree’s sap travels, on which many insects feed.
- Heartwood. Also called the “heart” of the wood, it is the center of the tree and is made up of physiologically inactive cells. It is much darker than sapwood, since no sap flows through it.
- Vegetable marrow. The core of the trunk itself is a flimsy substance from which the other layers are formed. It has no industrial use.
Types of wood
Prefabricated wood is made up of wood scraps.
There are many types of wood, according to their properties and appearance:
- Softwoods. They come from fast-growing trees, such as conifers: poplars, willows, pines, acacias, etc. They are friendly and easy to work with, they usually have very light colors and are the raw material for paper.
- Hardwoods. They come from slow-growing, deciduous trees such as walnut or oak. They tend to be oily and resistant, useful for floors, tools and furniture.
- Resinous woods. Particularly resistant to moisture, they are used for furniture and certain types of paper. They come from trees such as cedar or cypress.
- Fine woods. These allow for a better quality finish and more delicate work, highly sought after in art and architecture, for making musical objects or ornaments. They usually come from ebony, spruce or maple, for example.
- Prefabricated wood. Synthetic wood or wood made with wood remains, through conglomerate techniques or industrial agglutination techniques.
Woods can also be classified according to the length of their fibers (long grain and short grain) and the size of their grains (fine grain and coarse grain).
Uses of wood
Wood can be used to make entire houses.
Wood is an extremely versatile material that can be used to feed numerous human industries, such as:
- The manufacture of furniture, tool handles, containers, cabinets, tables or chairs.
- The construction of entire houses, of stairs within them, of parquet floors (parquet), windows, blinds or complete structures (bars, dining rooms, etc.).
- The manufacture of fences, gates, rural road signs, mailboxes, dog houses, bird houses, etc.
- The manufacture of ships, axles for train rails and parts of other vehicles.
- It serves as raw material for carving and crafts.
- It is used as a fuel material in wood-burning ovens, either for heating or cooking.
- It is processed to obtain the cellulose needed to make paper.
Advantages of wood
Wood is an abundant, economical and ecological materialsince it is completely renewable.
Despite Indiscriminate logging is a global ecological problemthere is always the possibility of replanting entire hectares of trees. Wood has various levels of elasticity and resistance, which makes it ideal for various carving and construction jobs.
Besides, Houses made of wood are cheaperfaster to make and provide an important feeling of safety and security.
Disadvantages of wood
Wood can house numerous living beings in it.
The woods They are susceptible to the action of environmental elementsalthough with the correct treatment they can be very resistant for years.
However, Wood fibers can fracture due to pressure or impacts, as well as corrosion, especially in the presence of environmental humidity (such as in coastal saltpeter).
Ultraviolet light is perhaps the chemical element that has the greatest impact on wood, degrading lignin and darkening the wood, making it more fragile.
On the other hand, wood It can host numerous living beings, such as termites (termites)ants, beetles, bacteria, and especially fungi and molds, which can degrade their molecules, drill holes in them or gnaw their surface.
Wood derivatives
Paper is obtained by processing wood.
Numerous by-products can be obtained from the remains of wood processing, such as:
- Paper. Processing wood to recover cellulose through various chemical procedures.
- Conglomerates. By collecting the leftover shavings or sawdust, mixed with glue (in a proportion of 85% to 15% respectively), conglomerates of different sizes are made which are used as construction material or as insulation.
- Plywood. Plywood panels or joints can be made with wood fibers to achieve a thicker and more resistant fabric, useful in the construction industry.
The timber industry in the world
The main wood exporting countries on the planet are: Chile, Austria, Brazil, Russia, Germany, Finland, Sweden, the United States and Canada.
Continue with: Forests