Basic properties of wood
Wood is a material with a large list of different properties. Some of them are positive, others are negative.
The main properties include:
- Humidity;
- Density;
- Hardness;
- Wear resistance;
- Susceptibility to deformation;
- Swelling;
- Thermal conductivity;
- Drying out.
Crafts and kitchen utensils
Source stroyres.net
Wood crafts have always been in great demand, and today is no exception. These can be various compositions, as in the top photo, or any individual figures depicting fairy-tale characters, tiny houses, boxes, and so on. It is noteworthy that crafts do not always require the skill of a cabinetmaker with a full set of tools - nature itself sometimes throws up fancy figures from branches and roots - all you need is observation and a flight of imagination.
Source rubankom.com
Today, wooden boards for slicing products are in great demand, especially if they are assembled, that is, glued together from scraps of the board, but the fibers are turned perpendicular to the plane. Kitchen knives practically do not become dull when cutting meat or vegetables, since the blade simply enters the soft structure, which then moves again. A wooden spoon can generally be called an indispensable attribute when cooking jam or jam, but borscht or fish soup from a wooden bowl is simply delicious.
Technological properties of wood
Technological properties are important when processing a material. These include load-bearing capacity, design advantages and pricing.
Environmental
Wood is the most environmentally friendly material currently available on the market. The only exception is glued building materials, which emit large amounts of harmful substances.
The environmental friendliness indicator is determined by strictly established standards, which may differ in different countries. Therefore, the characteristic is subjective.
Operational
These are indicators such as wear resistance, heat loss and sound absorption. In all these characteristics, wood compares favorably with other building materials. So, a 200 mm thick softwood beam is equal in heat resistance to a 600 mm brick wall.
- Wear resistance largely depends on operating conditions.
- So the wooden structure, built more than 100 years ago, is still preserved.
In order to protect wood from fire and increase its service life, there are now special fire-resistant compounds.
Designer
Wood is one of the most beautiful materials from a designer's point of view. The unique pattern of wood does not require the use of additional finishing materials and is used in many modern styles.
Price
The price-quality ratio of wood is one of the best among all building materials. Not the lowest cost of lumber is compensated by its wear resistance, thermal conductivity and sound insulation.
Hardwood
Ring-vascular hardwoods.
Oak grows in separate tracts in the European part of Russia, as well as in the Crimea and the Caucasus.
Oak wood is characterized by high strength and resistance to decay, the ability to bend, beautiful texture and color.
Oak wood is used in carpentry, furniture, parquet and plywood production. High strength and ability to bend determine the use of oak in car, ship, and wagon construction, and for the manufacture of staves for barrels. Oak waste and firewood are used for tanning and extract production.
ash grows in the middle and southern zone of the European part of Russia, the Caucasus, and Crimea. Ash wood is characterized by high strength and toughness, low tendency to cracking, and beautiful texture.
It is used along with oak wood. High impact strength and bending ability determine its use for the production of sports equipment (skis, oars, tennis rackets), in the wagon, ship, carriage, aircraft and automobile industries, for the manufacture of stair railings and tool handles, etc.
Elm grows in the European territory of Russia. Its wood is quite heavy, strong, tough, and has good bendability. It is used mainly in the hoop industry for the manufacture of rims, runners, arches; in car and mechanical engineering (screws) and in carpentry and furniture production.
Elm grows in European Russia and the Far East. The beautiful texture of elm wood is valued in furniture and plywood production.
Elm grows in the southern zone of the European part of Russia, in the Crimea, and in the Caucasus.
Elm is a poisonous species with narrow yellowish-brown sapwood and a brownish-brown heartwood. Its wood is similar to elm wood, so the areas of application are almost the same.
Disseminated-vascular hardwoods with softwood
Birch grows everywhere.
Birch wood is used for the production of peeled veneer, plywood, hunting rifle stocks, skis and laminated plastics, particle boards and fiberboards, cellulose, parquet, in construction, etc. Tar is obtained from birch bark.
Birch growths and burls are used as facing material in furniture production.
It is highly valued and used in the manufacture of souvenirs and artistic furniture.
Poplar. Poplar wood is soft and not very resistant to rotting. It is used in the production of cellulose, for the manufacture of dugout boats, troughs, wooden shovels, and wooden utensils.
The bark of sedge (balaber) is used to make floats for fishing nets.
Aspen. The use of aspen is limited by the presence of heart rot in the wood. The main use of aspen wood is in the match industry, for the production of viscose (rayon). Aspen wood is used to make toys, dishes, wood shavings, roofing tiles, shingles and shavings, shingles, roofing shavings, etc.
Alder. Grows in highly moist soils. Freshly cut white alder wood quickly turns red when exposed to air.
Alder wood is soft, light, and has a uniform structure. It is used in plywood, carpentry and furniture production, as well as for the production of box packaging.
Linden. Linden wood is soft, light, of uniform structure, cuts well, cracks and warps a little. The low formability of linden wood determines its use for the manufacture of drawing boards and models in foundry. Carved items, wooden utensils, pencils; Linden is used to make containers for food products (honey), wood shavings, and toys; Bast is obtained from linden bark.
Disseminated vascular hardwood hardwoods
Beech grows in the Caucasus and Crimea, in Belarus.
Beech wood is very durable, with a beautiful texture in a radial cut, bends well, and is susceptible to rotting. Beech wood is used to make bent furniture, staves for barrels for butter and petroleum products, parquet frieze, sliced veneer, drawing accessories (rulers, triangles), shoe lasts, cases for carpentry tools, and is used in wagon and mechanical engineering.
Beech wood is a valuable raw material for dry distillation, as it gives high yields of acetic acid and creosote.
The walnut grows in the Caucasus and the Far East. Walnut wood is quite heavy, hard and durable, and has a beautiful color and texture. It is well processed, polished and therefore highly valued in furniture and plywood production; used for interior decoration, production of turning and carvings, hunting rifle stocks.
hornbeam grows in the Crimea and the Caucasus. Hornbeam wood is very heavy, hard, resists abrasion well, and warps and cracks when dry.
It is used in mechanical engineering (screws, gears, loom drivers, tool handles are made), for the manufacture of turning products, shoe nails.
Maple grows in the Caucasus, Crimea and Ukraine. Maple wood is hard, dense, heavy and durable. It is used in furniture production, music industry, mechanical engineering (textile machine parts); Plane blocks, shoe lasts, etc. are made from maple.
Pear grows in the middle and southern zone of the European part of Russia, in the Crimea and the Caucasus. Pear wood is hard, heavy, and has a uniform structure. It is well processed and polished, imitating ebony. Used to make high-quality furniture and musical instruments. Sliced veneer. It warps a little and is used to make drawing accessories (rulers, patterns) and frames for optical instruments.
Plane tree or plane tree grows in the Caucasus and Transcaucasia. Plane tree wood is used in furniture production as a finishing material and for the manufacture of various artistic products.
Boxwood grows on the Black Sea coast of the Caucasus and in the Crimea. Boxwood wood is used to make wind instruments (flutes), weaving shuttles, engraving boards, buttons, carvings and turning products.
Rowan grows everywhere in Russia. The wood is dense, heavy, hard and durable, and resists impacts well. Rowan wood is used to make handles for percussion instruments, turning products, etc.
Physical properties of wood
Physical properties include those that can be determined without additional influence on the material. They can be determined by weighing, measuring or inspection.
These include:
- Appearance;
- Density;
- Humidity;
- Shrinkage and swelling;
- Thermal conductivity, sound conductivity, electrical conductivity.
Properties that determine appearance
Logging is distinguished by a wide range of properties characteristic only of wood:
- Smell - depends on the breed and the amount of different resins in the structure. The smell of wood cannot be confused with anything else.
- Color also depends on the breed. It can also differ between wet and dry boards, as well as between sick and healthy wood.
- Texture – the cut has a special unique pattern, which depends on the age of the trunk and the intersection of the fibers.
- Shine – will be more pronounced in dense rocks, depending on the number of rays emanating from the core.
Density
Measured at standard humidity. As humidity increases, density also increases. The indicator is also closely related to strength. The heavier the wood, the stronger and more valuable it is to manufacturers.
There are three types of density:
- High – more than 760 kg/m;
- Average – 510 – 750 kg/m;
- Low – less than 510 kg/m.
Humidity
Wood moisture content is the ratio of moisture contained in the trunk to the mass of dry material. Expressed as a percentage. A freshly cut tree will have higher humidity than one that has been lying around for several days. This is due to the fact that the plant absorbs water from the soil throughout its life.
Shrinkage and swelling
Shrinkage is an indicator that is checked by reducing the size of the material after drying. It begins after complete removal of free moisture. There are three types of breeds:
- Severely drying trees - birch, hornbeam, beech, maple, larch.
- Medium-drying - oak, fir, poplar, ash.
- Low drying - fir tree, cedar, poplar.
Swelling is one of the negative qualities of wood. This is due to the fact that the material absorbs moisture when the environment changes.
Thermal conductivity, sound conductivity, electrical conductivity
The thermal conductivity of dry wood is very low. This means that heat loss from wood with a moisture content below 12% is close to zero.
Sound conductivity shows the speed at which a material transmits a sound wave through itself. For wood, this indicator is a negative characteristic. Because wood conducts sound 16 times better than air.
Timber is not suitable for the manufacture of interior partitions and ceilings. At the same time, musical instruments made of natural wood sound excellent.
Electrical conductivity shows how quickly a material conducts electrical impulses through itself. This indicator will differ for different tree species. It is also affected by environmental conditions.
Conifers
Pine occupies about 1/6 of the area of all forests in Russia. The more common species is Scots pine. It grows in Crimea and the Caucasus.
Pine wood is a fairly soft material. Well processed. Used for the manufacture of window and door blocks, furniture, and staircases.
Spruce occupies 1/8 of the forested area.
Spruce wood, due to its greater knotty nature, is processed somewhat less well. Its advantages are uniformity of structure, white color and low resin content.
It is used in construction for the manufacture of window and door blocks, flooring boards, baseboards, platbands, cladding and layout, for the manufacture of household furniture.
Spruce is used to produce shingles, shingles, and shavings for egg packaging. Tanning materials for the leather industry are obtained from spruce bark.
Larch occupies about 2/3 of the area of all forests in our country.
Larch wood has high physical and mechanical properties: the density and strength of its wood is almost 30% higher than pine wood. It is highly resistant to rotting. Larch wood is heavy.
Larch wood is used in cases where high strength and resistance to decay are required (hydraulic structures, piles, pillars, ties, sleepers, mine support). In carriage building, larch wood is sometimes used instead of oak wood. It is used in furniture production because it has a beautiful texture.
Fir. Fir wood has the highest physical and mechanical properties and is not inferior to spruce wood.
Fir wood is used along with spruce wood.
Cedar. In terms of physical and mechanical properties, cedar wood occupies an intermediate position between Siberian spruce and fir wood, but in terms of resistance to rotting it exceeds them.
Cedar wood is well processed in different directions; used for the production of pencils, in carpentry and furniture production, for the manufacture of sleepers, mine stands, etc.
Yew . Yew wood has a beautiful appearance and is therefore valued in furniture production and is used for interior decoration, turning and carvings, and small artistic items.
Mechanical properties of wood
Mechanical properties show how much wood can resist external factors. These include strength, hardness, impact strength, deformability, and wear resistance.
Strength
The property shows how susceptible the material is to external influences, such as compression, prolonged bending and stretching.
- Depends on the direction of influence.
- Timber is much more resistant to loads along the grain than across it.
- Birch has the best strength indicators.
- Conifers are slightly less durable.
Hardness
Determines the resistance to the penetration of external metal objects (driving in nails, dowels, etc.). Wood is not the hardest material. With lateral impacts, the strength is significantly lower than with end impacts.
Impact strength
A property that determines the ability to withstand dynamic loads (for example, hammer blows) without visible damage for a long time. This indicator for wood is at a high level.
Flexibility
The ability depends on humidity. So conifers practically do not bend when dry. Therefore, before starting work they are wetted. This property makes wood an excellent material for creating furniture.
Wear resistance
Shows how wood can withstand long-term surface friction. Depends on the type of wood, humidity and cutting direction. The higher the moisture content of the material, the lower its wear resistance.
What functions does the stem perform?
- Supporting - the stem is the core of the plant, provides its support; place for leaves and flowers to grow;
- conductive - transport of dissolved substances from the root system to leaves and branches, new shoots;
- storage – ensures the constant presence of water and nutrients inside the stem;
- protective – protects against the action of dangerous agents and being eaten by animals (spines and thorns develop);
- vegetative propagation - for individual plants (citrus fruits, pineapple) the only way to produce offspring;
- photosynthesis - the presence of chloroplasts in green cells makes it possible to participate in energy conversion processes;
- assimilation of organic substances , for example cacti, in which the stem takes on the function of leaves;
- axial (mechanical) - brings the plant to the sun (leaves - for photosynthesis, flowers - for pollination).
