There is a lot of controversy about the origin of the building material “Finnish plywood”. Some argue that for the first time the technology was developed and applied in the Soviet Union, and then it was adopted in Finland, others - that everything was the other way around. The fact is the following: the production of types of plywood with the name “Finnish” is successfully carried out by domestic enterprises, while the quality of the finished materials is in no way inferior, and in some cases surpasses foreign ones.
Manufacturing process
Plywood of this type is a plate, very rigid to bend. The main properties of building material, ensuring its high popularity, are strength, lightness and water resistance. Birch veneer is used as feedstock. In lower grades, the core of plywood sheets may consist of coniferous wood. Finnish moisture-proof plywood is made only from birch. After drying, the veneer is cut and impregnated with alcohol or water-based solutions of bakelite resins. This treatment protects the wood from fungal damage, rotting, exposure to aggressive environmental factors, including moisture, high and low temperatures. Impregnation is carried out by immersion of veneer or smearing it on both sides. The adhesive composition must be at least E1 safety class. Then the sheets are stacked and treated with hot steam under a press. In this case, the veneer layers are glued together, forming a strong conglomerate. The presence of stratified fragments, swellings and air pockets in it is not allowed. The finished product is cut in accordance with established standards and a protective film is applied to the surface - laminated. The transverse edges are painted over with an acrylic moisture-resistant composition.
Technical properties
The thickness of the material varies from 6 to 40 mm, the standard sheet sizes are 2500 × 1250 and 2440 × 1220 mm. Density per 1 m³ - 650 kg. Along wood fibers, the modulus of elasticity of the material is not less than 6000 MPa. The outer surface of the plywood can be smooth or embossed. The latter is more convenient for cutting, it is used in cases where it is undesirable to slip the material, for example when installing the floor. A characteristic feature is a light brown or red-brown shade of the surface due to the covering film.
Laminated plywood is not inferior in resistance to low alloy steel or plastic. Its advantages:
- the ability to withstand temperatures in the range from -40 to + 50 ° C, resistance to melting and burning;
- moisture resistance;
- environmental friendliness;
- dielectric properties;
- high hardness and strength;
- simplicity in processing.
Application area
Finnish plywood sheets are one of the best materials for creating formwork in the construction of monolithic buildings, no matter how strange it may sound. Formwork made of modern wood materials is reliable and practical, as it can withstand concrete pressure and can be used repeatedly. This can save a lot. Formwork plywood must be at least 18 mm thick.
Other areas of application of the material:
- mechanical engineering and shipbuilding: manufacturing of bodies, containers, trailers, boards, inner lining of bus, wagon, yacht, boat salons;
- interior decoration of premises: installation of interior partitions, cabins, racks, shelves, racks, floors;
- production of outdoor advertising banners, signs and billboards.
The service life of products and cladding from this material is up to 15–20 years.
The only drawback of Finnish plywood can be considered fragility and vulnerability in the transverse direction, therefore it is undesirable to make small parts from it, and the places of cuts should be painted with waterproof paints when used. This limits the use of the material in furniture production.
Manufacturers
In Russia, several enterprises are engaged in the manufacture of Finnish plywood. The technological process is based on the use of domestic raw materials. Its processing is carried out using Finnish equipment.
- Investlesprom holding, which owns the Vyatka plywood factory. This company produces high-class Finnish laminated plywood only from high-quality birch veneer with Finnish equipment.
- LLC "Testament". The Nizhny Novgorod woodworking company has been operating since 2005. The range of products includes types of glued plywood of 1–4 grades, as well as finished products from not f.
- Production group "Sveza". This is the largest domestic producer, whose plants are located in various regions: St. Petersburg, Kostroma, Vologda region, Perm Territory. Sveza products have international certification.
- Syktyvkar Plywood Mill LLC is also one of the largest domestic manufacturers of large-format plywood and wood-shaving materials. The goods of this company are manufactured in accordance with high international standards.
Finnish plywood involves the use of sophisticated expensive equipment and belongs to the high class of wood building materials. For this reason, its price per sheet is slightly higher than other types.
The table shows the prices of distributors for laminated Finnish plywood, depending on the thickness and format of the sheets.
Thickness (mm) | Format (mm) | Cost, rub) |
6 | 2240×1220 | 650–700 |
6 | 2500×1250 | 750–850 |
15 | 2240×1220 | 1320–1400 |
18 | 2500×1250 | 1450–1600 |
24 | 2240×1220 | 1900–1950 |
24 | 2500×1250 | 2000–2100 |
Choosing Finnish plywood, it is recommended to stay on the domestic version, as a better, safer and more environmentally friendly, made strictly according to GOST. Chinese-made similar materials from poplar or bamboo veneer, in spite of lower cost, emit more formaldehyde, as they are processed with cheap adhesive solutions and are less resistant to external influences.