11. Materials from living organisms
Wood
In the olden days, most functional items were made out of wood. The raw material was found in the nearby forests, and most people knew how to make their own tools and furniture.
Although plastics have replaced wood as the most prominent raw material in items and construction, the old material still has its uses. One of the advantages of wood is that it decomposes in nature. It can also be safely burned.
Wood is a light material. It makes it possible for us to build houses and buildings without the help of heavy machinery. Wood as a building material also does not need a lot of energy.
Wood conducts heat weakly. This is why saunas are usually made out of wood.
Image on the left: Wood is a light material, which makes it possible for us to build large constructions without the help of heavy machinery. Image on the right: Saunas are usually made out of wood, because wood conducts heat very weakly.
Paper can be made out of various fibers and grains. Most commonly, it is made from wood pulp, because it is the cheapest available material. The image on the right below shows the edge of a newspaper sheet as seen through a microscope. In it, you can easily distinguish the grains of wood, which together form a unified sheet of paper.
Wasps also know how to make paper. They build nests by mixing wood and spit, which results in a paper-like structure.
Image on the left: The microscopic image shows the edge of a newspaper sheet. Image on the left: Wasps build nests from a paper-like material.
Other plant fibers
Cotton is a common raw material for fabrics, textiles and clothes. Cotton fibers are made from cotton seeds. The disadvantages of cotton are linked to growing it. Cotton farming takes up a lot of valuable water and requires the use of many environmentally harmful pesticides. Flax stalks are used to make linen cloth.
Cotton and flax are used as raw material for fabrics, textiles and clothes.
Hemp is another common fiber plant. Hemp stalks were used by the Vikings to create ropes, sails, clothes and fishing nets. Hemp can also be used to produce durable, thin paper.
The nettle plant is a relative of hemp. It is considered the oldest fiber plant in the world. Archeological evidence shows that stone age humans already knew how to make fishing nets from nettles. Later in history, it has been widely used as the raw material for ropes and sacks. In the 20th century, nettle was replaced by cotton as the most important fiber plant in the world. Recent evidence has shown that nettle fibers do not grow moldy.
Hemp and nettle can also be used to produce fibrous materials.
Animal fibers
The most common animal fiber in the world is wool. It comes from sheep. The most valuable type of wool comes from merino sheep. Sometimes, the fur of goats and camels are also considered wool. The undercoats of certain goat species, such as mohair and kashmir goats, are held in great esteem due to their lightness and heat-insulating properties.
The most common animal fiber in the world is wool, which comes from sheep.
In South America, fibers are gathered from native tylopods (relatives of the camel). The most praised source of animal fiber is the wool of the vicuna. Alpacas are the relatives of vicunas, and their wool is also held in great esteem. Camel wool comes from the camel's soft undercoat. It mainly comes from Asian camels, which have two humps.
Image on the left: vicunas roaming the South American desert. Image on the right: an Asian camel.
Even invertebrates produce animal fibers. Such invertebrates include spiders and the larvae of moths and butterflies. The most famous silk-producing moth is the silkworm moth. They produce fibrous material known as silk.
A silkworm moth.
Terminology
| Term | Explanation |
|---|---|
| material | A substance that can be used to make something. E.g. wood and metal. |
| fiber | A material that consists of long threads. E.g. cotton. |