Most people prefer to build their houses mainly from natural wood. Moreover, even accessories are selected from this material. And, despite the presence of wear-resistant analogues of artificial origin, which in recent years has become more and more, the tree is always highly regarded. However, in its original form, this natural material is short-lived - it rots, it warps at a high level of humidity. In addition, it is not able to withstand the attack of insect pests, including fungus. Heat treated wood eliminates many problems and is also a hygienic material.
Even in ancient times, masters thought about how to increase the service life of wooden products and structures. And, ultimately, it all ended with an innovative solution. What is this raw material?
General information
The term "tremodresin" hides material that has undergone heat treatment under the influence of high temperature. It can range from +185 ° C to +250 ° C. At the same time, no chemicals are added during the production process! As a result, new material of the 21st century is born that meets modern quality requirements.
Many consumers value environmental friendliness in their raw materials, no matter how much time has passed. And the physical and mechanical properties of materials are completely priceless. And it would seem that other modern counterparts, which are not inferior at all and have more chances for universal recognition. In reality, everything is a little different.
Natural material, and in particular heat-treated wood (what you now know), compares favorably with them, at least in that people will not soon abandon it. Perhaps this will never happen. Here, as with the classics - it is immortal and out of competition with fashion trends.
What did the ancient masters know?
The benefits of heat treatment of wood have been known to mankind for a very long time, and already in those days it was put into practice. Masters noted that pre-digesting workpieces using oil helps to increase the service life of products. Thanks to this treatment, the material ceased to absorb moisture, respectively, there is no rotting, and the shape remains for a long time.
But this is far from the only technique used. What has not been done in order to extend the life of the wood:
- Normans resorted to burning material on an open fire.
- The masters of Germanic and Slavic tribes held in high esteem and digestion.
- Even the Indians were familiar with the roasting technology - they increased the strength of their arrowheads and spears.
As for the examples, you do not need to go far for them. The evidence for the use of heat-treated wood is the old mill wheels. But many of them have survived to the present day!
Chemistry - both benefit and harm
Chemical processing of wood has also been widely used since ancient times, and is used to this day. Its essence lies in the impregnation of the material by various means. Among the most common formulations:
- antiseptics;
- polymeric substances;
- paints;
- varnishes.
Also, there were moisture protective films. The benefit of chemical treatment is an increase (and a substantial) in resistance to negative external influences. However, there is harm, because wood loses its main advantage - environmental friendliness.
Technology development
We have become interested in the thermal treatment of wood since the 30s of the last century. Scientists from Germany took the initiative, and a few decades later it was picked up by the Americans. Mankind has known for a long time what it is - heat-treated wood. Therefore, experts were busy conducting experiments and experiments. But in the end, the technology is not widely used.
In the late 80s in the city of Novy Urengoy in Russia, the foundation was laid for its own development of technology for heat treatment of wood. It is based on the experience of the ancient masters. And after receiving new material, the production of furniture and sports equipment began.
Around the same time, experts from other countries, such as Germany, Finland, France and the Netherlands, also took up the effect of high temperature. Scientists conducted studies that proved that because of this, structural changes occurred in the wood. As a result, the material was made more wear-resistant and durable, which expanded the scope of its application.
Finland
And yet, the technology for the production of heat-treated wood first began to emerge in this country. Its residents for the first time noticed how the effect of high temperature affects the indicators of material resistance. Samples were placed on various trees:
- birch trees;
- fir trees;
- pine trees;
- aspens.
In accordance with their methodology, the whole process consists of several stages:
- Moisture is removed from the fibers of natural material by drying in closed chambers at a temperature in the range of +130 ... + 150 ° C.
- Under the influence of high pressure and temperature (+200 ... + 240 ° C), as well as water vapor, wood hardens. At this stage, the material acquires a characteristic shade.
- The temperature regime decreases, the percentage of moisture content is brought up to 4-6%, no more.
The result of this cycle leads to the formation of a new structure in wood, and changes occur precisely at the molecular level. This is due to the splitting of the fibers and the bonds between them - this is precisely what affects high temperature and pressure.
The result of using Finnish technology - heat-treated wood is able to withstand moisture and not undergo deformation under heavy rains. And all by reducing the porosity of the surface of the material.
Developed Technologies
As many experts from all over the world note, today there are about two dozen technologies for heat treatment of wood. Many of them have patents and among them the most famous technologies are the following types of production:
- Thermowood is the native technology of Finnish craftsmen. According to this development, many factories operate in the country. At the same time, the Italian company Baschild and the French company BCI-MBS use this technology.
- German development is based on drying wood, which is conducted in a liquid medium of organic origin (oil) with alternating temperatures.
- Plato - this technology was developed by masters from the Netherlands. It implies thermal hydrolysis of wood under the influence of temperature conditions in the range from +160 ° C to +190 ° C.
- Retification is already our own production of heat-treated wood from French specialists. In this case, the process takes place under the influence of a higher temperature (+200 ... + 250 ° C) in an environment of oversaturated steam.
On the territory of the Russian Federation, as well as in the USA, Canada and some other European countries, proprietary technologies for heat treatment of wood have been developed.
Thermal Wood Strengths
As a result of exposure to high temperature, the natural material loses those qualities that limited its scope. At the same time, the beneficial properties of the tree are fully preserved. All this contributes to the fact that wood acquires new qualities that can be considered the advantages of this modern and innovative material.
Among the significant advantages, it is worth highlighting the following advantages:
- Durability - after heat treatment, the wood no longer absorbs moisture, respectively, does not swell and does not crack. This is achieved due to the breakdown of polysaccharides, which are a favorite treat for fungi and other pests.
- A high level of fire safety - heat-treated wood acquires hardness and density, which leads to the fact that it flares up very slowly than untreated material.
- Strength - thanks to the thermal “modification” procedure, the material is resistant to mechanical stress.
- Attractive appearance - heat treatment contributes to a strong manifestation of the structure of wood. Due to this, even simple varieties acquire a new guise that is in no way inferior to the appearance of elite breeds.
Largely due to these qualities, today this innovative material is just like hot cakes among professional builders and home craftsmen.
Classification
Since the thermal treatment of wood is carried out under the influence of a fairly high temperature with a large gap (+ from 150 ° C to +240 ° C), the whole thermal wood is divided into several classes.
The first group includes timber, which is processed at a temperature of not more than +190 ° C. Its surface is slightly tinted, and technical indicators are at a low level.
The second group is represented by heat-treated wood, fired at +210 ° C. This made it possible to increase its resistance to decay, and this can already be considered a high-strength material. Nevertheless, wood, to a lesser extent, is fragile and ductile.
The third group includes materials of the highest quality - here the process proceeds under the influence of the highest temperature +250 ° C. The result is very dense and hard wood. It is resistant to any external influences.
DIY process creation
Thermo-wood is produced on an industrial scale using special equipment. Those who are interested in how such a process can be translated into reality on their own will be disappointed. Completely repeating everything that is done at the plants will not work for the simple reason that the technology is very difficult to implement. And at home, it is simply impossible.
As you know, wood without proper treatment rots and quickly becomes worthless. At home, although it does not work out closer to the industrial scale of production, there are several good options:
- lubrication;
- burning;
- antiseptic treatment.
That is, it is still possible to make heat-treated wood with your own hands. Moreover, all this can significantly extend the life of wooden products and structures. Feeding and the roasting process are popular methods. They were used in practice by our grandfathers and their parents.
If necessary, it is possible to carry out treatment with chemicals that are specifically designed for this purpose. However, as already noted, the environmental friendliness of the material is lost. Therefore, they should be used consciously and not in all cases.
Good alternative
A wood blowtorch or gas burner is used to burn wood. Only pre-treated wood is wetted with water so that it does not catch fire. The procedure is carried out until a brown tint appears.
After firing, the carbon is removed from the wood with a metal brush. Heat treatment under the influence of a lamp or a burner can give the wood an aging effect, which is appreciated by many admirers. In addition, now the material is reliably protected from the development of fungi (including mold) for a long period of time.
At the same time, such a home-made technology for the production of heat-treated wood with their own hands does not allow to achieve those qualities of the material that thermal wood "born" in the factory has.