Preparation of raw materials (chips production)
As a rule, logs are delivered to the site. As soon as the raw materials arrive at the plant site, they are immediately unloaded using forklifts, a specially designed hydraulic manipulator or a crane with a grab grip. Some of the wood is stored at the raw material exchange, while some is immediately put into production. Next, the required volume of raw materials is immersed in steaming pools for a given time, after which they are debarked. If the wood has been recently cut down and is not frozen, then it is immediately sent for debarking and then into the flake machine. Currently, you can find three types of chipping machines that are used for the production of OSB chips. The already traditional flake machine for short pieces of wood. There are also disc chippers that shred entire logs. They use a different system for feeding and fixing wood during the cutting process. To process logs without preliminary bucking, rotary (ring) chipping machines are also used. These machines differ from disk machines in the design of the cutting tool.
Raw chips after the flaker are accumulated in special bunkers, from which they are fed in portions into the drum of the drying unit. In OSB production, three-pass or single-pass drum dryers are most often used, as well as their combination - three-pass/single-pass. In some industries you can see more modern three-section conveyor dryers. The concept of conveyor drying of OSB chips was borrowed from Food Industry- technologies for the production of potato chips. Conveyor dryers have a number of advantages over traditional drum dryers. First, conveyor dryers allow you to dry longer chips without damaging them. Secondly, the entire flow of chips is dried more evenly, and at the same time the temperature at the outlet of the conveyor dryer is lower than that of a drum dryer.
This is a very important circumstance, because The lower the temperature at the dryer outlet, the higher the fire safety of the process and the lower the emission of pollutants (volatile organic compounds). After drying, the chips are sorted to separate too small and too large chips from the main stream. Suitable chips are sometimes sorted additionally, especially if the chips of the inner layer will be laid out randomly on the molding conveyor, without orientation. In this case, larger chips correct form sorted to the outer layer, where the chips are oriented. The rest of the shavings are applied to the inner layer of the OSB board. Sorted chips are accumulated in dry chip bins. Fines and too large chips are transported to the dry fuel bunker of the boiler room.
The process of mixing chips with resin and paraffin is controlled most carefully. To resinize the shavings of the inner and outer layers, different mixers are used. They have the same design, but the composition of the chemicals supplied inside is usually different. In general terms, a mixer is a cylindrical drum that rotates at a set speed. Paraffin, resin and other glue components are supplied inside the drum through separate pipelines. But, no matter what kind of paraffin is used, raw or emulsified, it is introduced before the resin. For the inner and outer layers most often used different types resin The resin for the outer layer can be supplied in liquid or powder form, while the resin for the inner layer can also be phenol-formaldehyde or isocyanate. The consumption of isocyanate resin for chips of the inner layer is always higher, because it hardens faster and at a lower temperature than phenol-formaldehyde. Manufacturers often increase the number of mixers to have greater flexibility in resin type selection and to make it easier to switch from one adhesive formula to another.
Carpet formation
The orienting head of the outer layer chips is somewhat similar to farm harrows. It consists of a series of round discs that direct the shavings as they fall, aligning them parallel to the long side of the carpet.
The inner layer chip orienting head consists of star-shaped rollers with flat blades. By rotating, they align the chips parallel to the width of the carpet, perpendicular to the direction of movement of the conveyor. The dimensions of the elements of the orienting heads and the distance between them are adjusted to the size of the chips so that they fall through the rotating disks or rollers before they carry the chips beyond the limits of the orienting head. Layers with oriented chips are laid out on a conveyor moving below sequentially, one after another. The orientation of the chips in the layers alternates as follows: longitudinal, transverse, longitudinal (in 3-layer slabs). Each layer is formed by a separate orienting head and laid out by a separate forming machine.
During the strand carpet forming process, the density of the fill is continuously measured to ensure its uniformity. In modern forming lines, the carpet is laid out on steel flat or mesh trays, which are then fed into a hot press. Conveyors operating without pallets can also be used (in lines built on the basis of a continuous press).
Pressing
The carefully prepared shaving carpet is fed into a hot press. The press turns the loose chip mound into a slab and polymerizes the binder contained in it. The task of the press is to compact the chip carpet and increase the temperature inside it to a given value. The curing temperature of the resin is between 170-200°C. Pressure and temperature must be measured within 3-5 minutes. The following types of presses can be used: multi-story, single-story, continuous. Single- and multi-deck presses are in demand for the production of OSB boards of small and medium capacity.
The continuous press is equally suitable for the production of MDF, chipboard and OSB. Its advantages: increased productivity by 10-20%, reduced variation in thickness of finished products, improved quality, simplified maintenance, minimal installation costs. The steel belts of the continuous press are heated using thermal oil to a temperature of 220 °C. The estimated curing time is 9 seconds per millimeter of slab thickness. Dust and exhaust steam after the press are removed using a wet fan.
Multi-deck presses of this type have earned a good reputation due to their high reliability. Its advantages: uniform heating of the entire heating plate, reliable hydraulic system, automatic system controls, simultaneous mechanism, possibility of producing door panels.
The single-deck press is designed to increase the ROI of low-capacity lines. The features of this type of press are: rapid changes in production parameters, changes in the length and width of the slabs, ensuring the exact width of the slabs and a fast pressing cycle.
OSB - OSB (Oriented Strand Board) - modern material For modern construction. OSB equipment operates around the clock. Manufacturers of equipment for the production of OSB boards indicate capacity at the rate of 334 days per year, 31 days for scheduled preventive maintenance.
Oriented strand boards (OSB) that appeared not so long ago became a fundamentally new type of wood-based particle boards. This material retains the best qualities natural wood and does not have the disadvantages of analogues - plywood or chipboard.
Oriented strand board is a three-layer material made of " wood wool» - elongated (6-9 cm) coniferous wood chips. The main feature of OSB slabs is the different orientation of the chips: in the upper and lower layers the chips are located along the length of the entire slab, and in the middle layer - perpendicular to the covering layers.
It is the multidirectionality of fibers in the layers that ensures the exceptionally high mechanical strength of OSB boards - it is 3 times higher than that of plywood or chipboard. At the same time, the flexibility inherent wood materials, is saved.
All three layers are impregnated with waterproof waxes and resins and pressed into a single whole under the influence of high pressure and temperature. identical large chip sizes and modern method pressing ensures the homogeneity of the material throughout the entire slab, the absence of voids and cracks in its thickness and chips along the edges.
Small waste chips are removed during production, due to this, a significant reduction in the amount of connecting adhesives in the composition of OSB boards has been achieved - only 2-3%. OSB is almost entirely a purely wood material. At the same time, OSB boards do not have the disadvantages of pure wood - they are not susceptible to rotting, fungal attack, and are not flammable. The most important property of OSB boards is that the boards have almost zero hygroscopicity. This property underlies the use of oriented strand boards in roofing construction. To date no best material for the base for roofing. According to the degree of hygroscopicity and strength, OSB is divided into groups that determine the scope of application of a particular type of material. The use of OSB boards is based on their excellent consumer qualities - strength without loss of flexibility, moisture resistance, lightness.
First of all, these are all branches of construction. Device continuous sheathing for all types of roofing and flooring, covering walls and ceilings, including decorative ones (OSB does not emit formaldehyde into the air), creating removable formwork. OSB material is indispensable in attic construction.
In North America, OSB boards are the structural basis for all cottage construction, acting as a frame in any element of the building. The exceptional strength of the material, its environmental friendliness, and the durability of OSB structures at a low price make the material a leader in its market segment.
are divided into groups that determine the scope of application of a particular type of material. The use of OSB boards is based on their excellent consumer qualities - strength without loss of flexibility, moisture resistance, lightness. First of all, these are all branches of construction.
Installation of continuous lathing for all types of roofing and floor coverings, cladding of walls and ceilings, including decorative ones (OSB does not emit formaldehyde into the air), creation of removable formwork.
- OSB has a uniform internal structure, and both surfaces have the same quality.
- OSB contains over 90% wood
- OSB-2 (OSB2) - conventional oriented strand board
- OSB-3 (OSB3) - moisture-resistant oriented strand board
5 OSB manufacturing companies on the Russian market
All manufacturers provide a 25-year guarantee for their boards, however, the production of OSB in Western Europe has a longer tradition, which makes the quality of these boards impeccable, and their characteristics fully comply with the requirements of the European standard EN 300. Boards produced under the control of the KRONOGROUP concern in Poland, Bulgaria, Lithuania, Romania and the Czech Republic are distinguished by quality close to German, as well as a more affordable price. Products from American and Canadian manufacturers are thinner due to the use of the English system of measures. The difference is approximately 4%. Another feature is the higher degree of looseness of the slab compared to European analogues, which makes installation faster and easier. Some manufacturers from the North American continent cover the end part of the slab in blue. These plates are different good quality, but when calculating the required quantity, it is necessary to take into account the difference in sizes, which are slightly smaller.
LIST OF POPULAR MANUFACTURERS REPRESENTED IN RUSSIA
Bolderaja OSB Superfinish (Bolderaja OSB Superfinish), Latvia
This manufacturer is the largest wood processing enterprise in the Baltic countries. The company's entry into the international concern KRONOGROUP in 2005 made it possible to ensure the European level of products and give them access to European markets. The slabs, in terms of their physical and mechanical characteristics, meet all the requirements of international quality standards and are manufactured in accordance with ISO 9000.
KronoplyKronoply GmbH (Kronoply GmbH), Germany
This company, which began its activities back in 1991, is also part of the Swiss KRONOGROUP concern. The products are distinguished by characteristic German quality. OSB production is the main activity of this large enterprise, whose daily output of boards reaches 1 million square meters.
Kronopol, Poland
This plant, with a twenty-year history, also produces slabs in accordance with the standards of the KRONOGROUP concern, exporting products throughout the world. Russia is one of the highest priority markets for the manufacturer, which is one of the largest in the world.
EGGER OSB (Egger), Austria
This manufacturer, with more than 50 years of history, produces high-quality OSB in accordance with the generally recognized European standard EN 300. The production association, which started as a small family business, now includes 16 companies located in five European countries.
GLUNZ OSB (Glunz AG), Germany
This manufacturer is part of the large industrial group Sonae Industria (Portugal), whose factories are located almost all over the world. The company produces OSB boards of various thicknesses (6-40 mm) using the latest equipment. The products meet the requirements of the European standard EN 300.
OSB Norbord, Canada
A large industrial association comprising eleven factories for the production of oriented strand boards located around the world, two of which are located in Europe.
OSB Louisiana Pacific, Canada
One of the oldest manufacturers of OSB boards and a world leader in the production of these materials, including 29 factories located in the USA and Canada.
Georgia Pacific (GP), USA
One of the oldest companies, the history of production of oriented strand boards goes back almost 30 years.
OSB Arbec, Canada
This is the only company on the North American continent that divides its slabs into two types: American (characterized by high standards of strength and environmental safety, as well as the presence of one corrugated side) and European (characterized, in addition to quality, by increased moisture resistance).
6 Laying OSB on the floor
Due to its moisture resistance, environmental safety and excellent technical specifications, OSB (OSB) boards are an excellent basis for any floor coverings, be it laminate, linoleum or carpet. They are perfect for installing a subfloor under tiles or parquet. Since the warranty period for oriented strand boards is 25 years, these coatings will last a very long time. Types of bases for laying slabs:
● concrete screed;
● logs (beams) of the first and second floors;
● on supports (brick columns that are laid out on the first floor of houses).
Selecting OSB
OSB 3 (boards designed for use in conditions of high humidity) from Western and Eastern European manufacturers are considered the most suitable for laying on the floor. This product meets European moisture resistance standards and is characterized by high density.
Calculation of the need for slabs
When calculating the required number of sheets, it is necessary to take into account the 7% loss of coating during cutting.
Choosing slab thickness
If the slabs are laid on a concrete floor (screed) as a leveling surface to provide heat and sound insulation, the recommended OSB thickness is 8-10 mm.
When laying on logs (beams), the thickness of the slab depends on the distance between the supports. With an interval width of 400-600 mm, the required OSB thickness is 15-18 mm, and with a width of mm it will be 22 mm.
Laying on joists
When installing a subfloor made of oriented strand boards, laying is done on joists. Between OSB 3 boards it is necessary to leave a gap of 3 mm on each side. With the “floating” method of laying slabs, a gap of 12 mm wide is required between the wall and the OSB. The slabs are joined on joists along a narrower edge. Long edges also require additional support.
Due to the increased load that falls on the floor, it is advisable to use a two-layer OSB coating. The layers are positioned perpendicular to each other and secured with 2-inch razor or spiral nails. The plates are fastened with self-tapping screws at intervals of 300 mm per wooden beams. At the joints of the slabs, the recommended step length is 150 mm. To ensure reliability and rigidity, you can additionally glue the slabs to the joists using a special assembly adhesive for wood.
Laying on a concrete screed
When laid on a concrete screed, OSB slabs are attached using self-tapping screws directly to concrete floor or on top of insulation, which provides increased thermal insulation and resistance of the future floor to mechanical loads.
Laying under linoleum
When laying OSB boards as a base under linoleum, it is necessary to achieve maximum smoothness of the joints between the boards, for which it is advisable to use panels of the minimum permissible thickness. The 3mm wide gap must be closed using flexible silicone sealant. If during installation a single connecting seam is formed, then thermal gaps must be made from the wall side.
Under ceramic tiles
Oriented strand boards OSB (OSB) are perfect as a base for ceramic floor tiles, providing additional thermal insulation. To lay tiles over an OSB subfloor, a special mineral adhesive is used, which is used to bond wood and ceramic surfaces. The tiles will adhere perfectly to such a floor.
7 OSB frame houses
Houses built from OSB are usually called “Canadian” and “frame-panel”. Construction technology frame houses has been widely used all over the world - from European countries to North America. Such houses can be built even in seismically dangerous regions ( frame houses withstand fluctuations up to 9 points) and in permafrost areas (can be used at temperatures down to minus 40). The technology of their construction involves the use of a wooden or steel frame, as well as sandwich panels made of oriented strand boards OSB. Walls, partitions and even the roof are all made from such sandwich panels.
What is an OSB sandwich panel?
This panel is a kind of sandwich, consisting of two OSB boards and an inner layer of insulation. The latter can be polystyrene foam (both granulated and extruded), polyurethane foam, insulation based on mineral wool or glass wool. Mineral wool it is advisable to use in conditions high humidity, since in this way the walls are able to “breathe” and excess moisture easily evaporates. This avoids the formation of condensation and the development of mold on the walls. A para-insulating layer is laid between the insulation layer and the slab, which is necessary to protect the walls of the house from excess moisture and ensuring a favorable climate inside the cottage.
Sandwich panels are produced industrially. Panels are cut at the component stage according to predetermined dimensions, which ensures high quality cutting and absence of joint defects. During technological process All layers of the sandwich panel are glued together with one or two-component urethane adhesive. The drying time for each layer of glue is only 5 minutes. The finished panel is placed in a press for 30-minute polymerization. After a day, the sandwich panels are ready for use.
Additional items
In addition to sandwich panels, structural elements such as blocks, corners, and transitions are used in the construction of frame houses. Their production technology is completely similar to that of sandwich panels.
What is the difference between OSB houses
Excellent thermal insulation
The main advantage of such buildings is their high heat-saving characteristics. The thickness of the insulation is 100-200 mm, which makes OSB sandwich panels 8(!) times warmer than brick walls. A layer of mineral insulation 200 mm thick corresponds to a 2-meter thickness brick wall. At the same time, the walls of such a house provide excellent air circulation, “breathe”, saving heat and not allowing heat to pass through.
Ecological cleanliness
An important advantage of “Canadian” houses is their environmental safety, comparable to wooden cottages. It is primarily due to the properties of wood, the material on which OSB boards are made.
Design flexibility
This construction technology leaves significant scope for a variety of architectural solutions, while being very economical both in terms of money and time.
Speed of construction
When building frame houses, you do not need to wait for the house to “settle” or dry out, but you can immediately begin finishing. Typically, the construction period for structures of this type, taking into account all construction work, does not exceed 6 months.
Reliability
Contrary to fears, the warranty period for such houses is at least 70 years.
Lightweight design
This technology is characterized by minimal load on the foundation, which makes it possible to install shallow columnar foundations.
8 How safe is OSB for our health?
The environmental safety of OSB boards is confirmed by their compliance with the requirements of the international standard in the field of environmental safety E1. All environmentally friendly materials used in residential premises meet this standard. Boards made in Canada and the USA are certified according to APA and TECO standards, which also means they are suitable for residential premises. Regardless of the level of moisture resistance, OSB-2 and OSB-3 boards have the same degree of environmental safety. What materials are used in the production of slabs and how harmless are they?
Wood
In Europe, mainly coniferous wood (spruce and pine) is used for the production of boards, which gives the finished product a light shade and a characteristic pine smell. In the USA and Canada, the main material for the production of boards is wood shavings from species such as aspen, poplar and ash. Pine slabs have the highest resistance to moisture and rot. They are practically not susceptible to the harmful effects of insects, which can pose a danger to OSB during prolonged exposure to high humidity conditions.
Resins
Some waterproof resin is added to the chips prepared for subsequent pressing. Typically, the percentage of resin content in the board is 7-8%. Melamine resin-modified phenol-formaldehyde resins are used as the binder for the outer layers. Carbamide resin is used for the inner layers. The resin combination may vary among different board manufacturers.
Carbamide CO(NH2)2, the so-called "urea", or amide carbonic acid, widely used as a nitrogen-containing fertilizer and mineral supplement to feed in agriculture.
Melamine-urea-formaldehyde resins also safe for humans. Formaldehyde (HCOH) is produced from methyl alcohol and is considered a substance harmful to humans. However, the stoves themselves are quite safe from an environmental point of view. Although formaldehyde resins release nerve gases when they evaporate, the presence of melamine neutralizes the dangerous effects of formaldehyde. We should not forget how much importance is given to material safety issues in the West. Consumers from Europe and North America are very scrupulous in matters of environmental cleanliness. Nevertheless, OSB is widely used there, including in the construction of medical and children's institutions. The European class E1 assigned to OSB boards means absolute safety with regard to formaldehyde emissions. Even pure wood, generally recognized as an environmentally friendly material, belongs to this class. safe material. So plywood, for example, corresponds to class E2. In addition, the combination of melamine and formaldehyde gives oriented strand boards strength and reliability in operation.
Paraffin emulsion
To improve water-repellent properties when producing boards in Europe, paraffin emulsion is added to their composition. This substance also increases the level of protection of the slab from insects and microorganisms. Such coatings do not require additional treatment with antiseptics (fungicides).
