MDF: what is it? Features and scope of the material. mdf board

MDF is board material, the raw material for which are dried wood fibers. Due to its properties, it is widely used in construction, furniture production and interior design, so the volume of MDF production in Russia is increasing every year. Its name is an adaptation of the English MDF (medium density fiberboard) and stands for " medium density fibreboard."

European standards for the physical and mechanical properties of MDF boards

The market presents goods of both domestic and European production. However, in Russia, GOST has not yet been developed, which MDF boards must comply with. domestic producers adhere to either their own standards or the ANSI A208.2 standard used in the West.

Features of the technological process and equipment for the production of MDF

The production technology is similar to the manufacturing process and fiberboard, although these two materials are noticeably inferior to MDF in strength.

The manufacture of such plates began in the United States in the mid-60s of the XX century. Of course, back then the production process was quite different. Later in Sweden, the American technology was slightly modified, and this material began to gain popularity. To beginning of XXI century, the annual production amounted to 20 million cubic meters. The main producer today is China.

Stages of MDF production

The production process of MDF can be divided into five stages.

Stage 1 - preparation of raw materials. For the manufacture of MDF in wood-industrial production, conventional round logs any kind of wood. With the help of a debarking machine, the bark is removed from them. Then, on chippers, the logs are crushed into technical chips. To remove foreign impurities (dirt, sand) from the chips, they are washed. Before the next step, the chips are heated with steam.

Stage 2 - preparation of fibers. The production equipment, called a refiner (or defibrator), grinds the steamed wood chips to a state of fibrous wood pulp. A substance called lignin is released from it, which ensures the binding of fibers. Additionally, urea-formaldehyde resins are used as a binder. Then air is removed from the mass.

Stage 3 - molding and primary pressing. On the forming machine, the mass is compressed into a carpet. After that, it is sent to the preliminary press. This stage is needed in order to remove air bubbles. If this is not done, then the plate will crumble.

Stage 4 - pressing. Material in the form of a tape falls on the main press. This stage can be divided into three stages. At the first stage, at a temperature of 200 to 230 °C and a pressure of up to 350 MPa, the surface of the slab is formed. At the second stage, the temperature drops to 190–210 °C and the pressure to 40–120 MPa. The central part is warming up. The third step is thickness calibration. Heating stops, and the pressure varies from 60 to 150 MPa, depending on the desired thickness. Then the tape is cut into plates and cooled.

Stage 5 - grinding. This stage is necessary to correct the thickness and eliminate surface defects.

If necessary, the plates are decoratively processed.

The main types of MDF are:

• painted;
• laminated;
• veneered.

Although their production is more expensive than slabs without decorative finishes, the cost of production still remains lower than that of wood, and in terms of its properties, MDF surpasses both it and chipboard.

Painted MDF

Staining occurs with the help of enamel. Depending on what kind of enamel was used, painted MDF can be:

• matte;
• semi-matte;
• semi-gloss;
• glossy with different textures.

The production process of such MDF boards begins with a primer using an airbrush. This is necessary for deresining and increasing moisture resistance. The material is dried and primed again to level the surface. The last step is the application of enamel.

This type is most often used for finishing kitchen and commercial equipment, as well as as individual parts of combined furniture made of chipboard. In addition, it is very popular with designers, as it allows you to easily change the interior of any room.

The production method of this type is to cover the material with a thin film of PVC, melamine or paper impregnated with a special resin. The film is glued to the surface using a press with high pressure. To increase wear resistance, apply not one, but several layers of laminate.

The laminated board not only looks beautiful, but also has more high performance than the non-laminated version. Thanks to this, laminated MDF is the most common wood-based panel on the market. It is used in the production of skirting boards, facades, frame structures, partitions and ceiling panels.

The color palette of the laminate is very diverse, but the most popular are colors that mimic natural wood.

Veneer is wooden plates up to 5 mm thick. Before veneering, the slab must be sanded and puttied. Then a veneer is placed on its front side. The production technology is divided into three types:

• with a cold method, the veneer is glued due to special substances;
• in the hot method, veneer gluing occurs due to the impact high temperature;
• at membrane method the veneer is connected to the board under vacuum.

Veneered MDF outwardly is very similar to wood, and in terms of such parameters as durability and service life, it overtakes it. It is used mainly in the manufacture of furniture and interior design.

Characteristics of MDF boards

There are two grades of MDF. The plates of the first grade do not have any flaws. Those that belong to the second grade may have minor defects that do not affect their strength. The thickness can be from 6mm to 24mm. Lignin and urea-formaldehyde resins are responsible for the strong bond of the fibers. In the production of MDF, only lignin is never used, resins are always added to it.

Advantages of MDF:

• In terms of strength, fiberboards are only slightly inferior to natural wood and are many times superior to chipboard in this parameter.
• Due to the uniform structure and high density There are no air pockets in the material. Thus, high moisture resistance is achieved.
• Plates retain their dimensions and appearance for a long time, do not dry out and do not crack.
• This material can withstand high humidity, thanks to special impregnations, it is not susceptible to mold and insects.
• Due to the variety of finishing materials, MDF products can fit into any interior.
• To install MDF, you do not need to be a specialist or have a special tool.
• If processed MDF cutter, you can achieve a three-dimensional relief.
• Cheaper to buy than natural wood.
• There are fire-resistant types treated with special compounds.
• For production, only natural materials are used, so it is environmentally friendly.

Disadvantages of MDF

There are several disadvantages when using this material:

• It will weigh more than a real wood panel of the same size.
• Using screws or nails will damage the structure of the material.
• For installation, it is necessary to pre-drill holes, and then use special screws.
• When processing with a cutter, a lot of dust is released, so a respirator is required.
• Unlike wood, MDF is not well suited for use as load-bearing structure especially horizontal.
• Phenol-formaldehyde resins used in the production of MDF are harmful to humans.

Scope of use of MDF boards

Today there are more than 300 products for the manufacture of which MDF is used.

This material is used in the field of design. From it are created decorative panels for walls and ceilings, window sills, door leaves and air ducts.

Fibreboards are used as Construction Materials. They make T-beams, which are used to create ceilings. Waterproof MDF, varnished, used as roofing lathing.

This material is especially popular in the furniture industry. It is used to create armchairs and chairs, grand pianos, steps and railings, and tables.

Furniture made from laminated or veneered wood fiber is suitable for high humidity areas such as the kitchen or bathroom.

Video: MDF board production

When planning a renovation or buying furniture, you always want to know more about existing materials, their advantages and disadvantages. Having comprehensive information, it is easier to understand what operating conditions certain things are intended for, calculate the approximate service life and make conscious choice. This article will focus on MDF - a substitute for solid wood, which is often confused with particle boards. With a number of advantages, which will be discussed below, this material is excellent for construction, interior decoration, furniture, doors and decor.

What is MDF?

The abbreviation MDF is a transliteration of the English term Medium Density Fibreboard, which means “medium density fiber board”.

This material consists of pressed crushed sawdust mixed with binders. It is produced in sheets with a thickness of 3 mm to 6 cm. fibreboard manufacture furniture, construction and finishing elements, packaging and other things. In fact, it is an inexpensive substitute for wood, made from waste products from the forestry industry.

Processing MDF is much easier than natural boards, moreover, it does not dry out, does not crack, perfectly retains heat and has good soundproofing properties. Compared to particle board, this material is more environmentally friendly, since it contains much less formaldehyde resins.

To disadvantages of MDF include instability to moisture and mechanical stress, as well as rapid flammability. The service life of MDF products under normal conditions is about 10 years.

Sometimes MDF stands for "fine wood fraction" and this is not a mistake at all.

The fact is that for the production of this material, raw materials (chips, shavings, sawdust) are carefully crushed, turning almost into dust. To do this, they are first heated with steam to 100°C and brought to a moisture content of 80%, after which they are placed in a defibrator and ground. Melamine-modified urea-formaldehyde resins and paraffin are added to the fibrous mass. Then all this is dried for several seconds with hot air at an average temperature of 200 ° C and enters the compacting hopper.

The resulting mixture is leveled with a roller along the conveyor, forming a continuous slab. Then a press is lowered from above with a pressure of 350 MPa and the material is heated to 230°C. Under such influence, it is fused, compacted and gains strength. Subsequently, the pressure is reduced by about a factor of three, and the thickness of the sheet is adjusted already without heating.

The cooled strip is ground and cut with a saw into slabs. At the last stage, a decorative coating is applied.

Medium-density fiber boards, which are used for the production of furniture and interior decoration, depending on the type decorative coating subdivided into laminated, painted and veneered.

Laminated

Lamination involves hot gluing on the MDF surface of any decorative material. It can be tarred paper, melamine, and most often pvc film. The front material tightly adheres to the base under pressure, which ensures high aesthetics of the plates for the entire period of use. There are a huge number of laminate textures - stone, leather, ivory, various fabrics, but the most popular are wood imitations.

Painted

The use of modern paints and varnishes over a leveling primer layer makes it possible to make sparkling mirror-gloss or noble matte panels from grayish MDF sheets. This processing is often used for kitchen furniture(which is important to protect from moisture), as well as other interior elements in the Art Nouveau, hi-tech and minimalist styles.

Veneered

Veneer is a thin, beautiful cut of natural wood. It is glued to the plate, giving it a complete external resemblance to the original. Veneered MDF panels are used to make doors, walls, chests of drawers and a huge number of other things.

In general, this is probably the most expensive type of finish, although the cost depends on the quality of the coating itself. It looks and feels like real wood, sometimes even rare, unusual species.

Properties and characteristics of MDF panels

Wood fiber boards are used in modern world no less popular than natural boards. There are a number of reasons for this, namely:

- strength - there is no air between the fibers of the pressed sheets, so the material does not crack or crumble, it keeps its shape for a long time;
- ease of processing, including decorative - it is easy to cut out any shapes from MDF, cut out voluminous decorations, and even special technology give it soft curves;
— a large selection of front coverings, which allows you to find the perfect option for any interior.

After impregnation with special substances, film lamination or coating with latex water-repellent paint, MDF can be used even in wet rooms such as bathroom and kitchen. Products marked E1 are approved for use in living rooms(this means that 100 grams of the plate emit no more than 10 mg of formaldehyde, that is, the allowable sanitary rules norm). In any case, there are several times more harmful fumes from chipboard.

MDF panels come in class I (without flaws) and II (small aesthetic flaws, bumps or slightly larger blotches are possible).

Application of MDF

Furniture

Medium density fibreboard products are a real find for everyone who wants to furnish their home, office or public place in a beautiful and quality furniture for a relatively low price.

As a rule, MDF is used for cabinet options - cabinets, headsets, shelving, tables, bedside tables, chests of drawers made of this material look very modern and perform their functions perfectly.

However, often it also forms the basis of sofas, soft chairs, beds. Covered with laminate or veneer, with embossed patterns or interestingly painted, MDF furniture will help to create a cozy and warm atmosphere anywhere.

Construction and repair

MDF perfectly copes with the role of a universal substitute for wood and in the arrangement of buildings. Beams, partitions are made from such plates, ceilings are sheathed with them, walls are insulated, plinths, corners are made, door frames, doors, stairs, railings and window sills.

But where such panels should not be used is on the floor (they are quite soft and can be deformed), as well as in outdoor decoration and in rooms with very high humidity.

Cutting any shape or cutting out a pattern from MDF is not difficult even for those who have never worked with wood and do not have special machines. This activity is somewhat reminiscent of the processing of drywall.

When manipulating MDF, it is worth remembering that it does not allow the reusable use of self-tapping screws and nails. If you need to make such a fastening, holes are first drilled in the material, and then the elements are connected using bolts and nuts.

And products from this material are quite profitable business. At proper organization such an enterprise will allow you to get big profits and win a leading position in the market. The manufacture of MDF must be approached no less responsibly. Getting high-quality plates will not go unnoticed among buyers, which will positively affect business development.

Business development prospects

The production of MDF can bring great profits even for a novice entrepreneur. The parallel launch of several lines for the production of boards, paper and various products from such materials will help to achieve great success and consolidate its position in the market. This approach is possible because the same raw material is used for the manufacture of these products - wood pulp.

Good development prospects exist when operations for the production of fiberboard and various MDF products are included in the production process. The most popular of them are furniture facades, and so on.

If desired, waste-free production can be organized. All waste from the release of materials is compressed into or pallets, which are to be sold. If there are opportunities on the production area, it is recommended to additionally place equipment for lamination. In this case, you can produce laminate and other Decoration Materials which will help to significantly increase the profit of the enterprise in a short period.

Market Analysis

by the most popular material for the manufacture of furniture in the domestic market is considered laminated chipboard. To obtain such plates, you do not need high costs, and the production process itself can be organized without much difficulty.

But the release of such material may not be profitable, despite the good demand in the market. This is due to the fact that in Russia there are many small and large enterprises that have been on the market for more than one year and have gained popularity among buyers. Therefore, joining this sector is not easy, especially for a budding entrepreneur.

It is better to start in those regions where the market similar materials poorly developed. You can choose the option when they are made in combination with furniture. It is these products that are in great demand among buyers, so when setting up its production, you can count on big profits.

If the way of manufacturing furniture is chosen, it is possible to organize the release of other materials that are used no less often, like chipboard. These include fiberboard or MDF. If you purchase equipment for the production of boards of the latter type, you can count on a great demand among buyers. MDF is widely used not only in the furniture industry, but also in construction for sheathing various surfaces.

What equipment is used for the production of plates

The production of MDF board is carried out using the following equipment:

• debarker - used to remove bark from the surface of wooden logs, which degrades the quality of the material;
• chipper - grinds wood to obtain particles of the desired size;
• refiner (defibrer) - grinds decorative chips of fibrous mass, which can even be used for;
• dryer (dispersant) - helps to reduce the moisture content of the raw materials used to optimal levels;
• cyclone (air separator) - separates raw material particles unsuitable for further processing;
• forming machine - performs the molding of prepared raw materials;
• presses of various configurations - necessary to obtain material with excellent operational characteristics and appearance;
• surface grinding machine - used to obtain a perfectly flat and smooth surface;
• conveyor belts - used to supply components from one production process another;
• filters and chip extractors - remove dust and waste obtained during the processing of wood;
• component dispensers, etc.

Production technology

The production of MDF is carried out in several successive stages, for which specific equipment is used.

Preparation of the necessary materials

For the production of MDF, it is necessary to properly prepare the raw materials. For the manufacture of such plates is used round wood, which is subjected to the following processing:

• The tree is debarked in special machines.
• Prepared logs are cut into chips.
• The received raw material is sorted and washed. This allows you to get rid of foreign inclusions - sand, dirt, small pebbles.
• The wood chips are heated by steam.

Fiber preparation. The prepared chips are crushed in a refiner, which makes it possible to obtain a special fibrous mass. Subsequently, additional ingredients (resins and other substances) are added to it. The resulting mass is sent to drying, where its moisture content is reduced to 8–9%. After such preparation, she is sent to a cyclone, where, under the influence of powerful air currents large fractions of material unsuitable for the production of MDF are removed.

Plate shaping. Specially prepared raw materials are shaped, which is carried out in several stages:

• Wood fibers are fed to molding machine where they are evenly distributed over the surface by special rollers.
• The formed carpet is weighed and sent to the next stage of production.
• The raw material is subjected to preliminary pressing, where excess air is removed from the thickness of the material.

Final pressing. Pressing the MDF board takes place in several stages. The material that is obtained after the completion of the previous stage of production is fed in a continuous belt to the main press. It performs several operations:

• forming the surface of the MDF board - is carried out at a temperature of 200–230 ° C and a pressure of up to 350 MPa;
• heating the central part of the material. Operating parameters reach the following values: temperature 190–210 °С, pressure 40–120 MPa;
• calibration of MDF boards. It is carried out at a pressure of 60–150 MPa without additional heating.

Grinding. In the manufacture of MDF, sanding is the final step in the manufacturing process. After pressing, the surface of the plates may have minor irregularities and various defects. They can be removed on a surface grinder.

Where are MDF boards used?

The scope of MDF boards is diverse and includes the following:

• production of furniture products;
• material for interior decoration (in the form wall panels, flooring);
• production of cases for acoustic systems. MDF absorbs sound well, which explains this way of using boards;
• production of containers and gift boxes;
• production is carried out furniture facades with thread elements.

If you follow all the rules in the MDF production process, the resulting materials will differ high quality. This will lead to success in the market and large profits, which is necessary for the subsequent development of the business.

The history of MDF furniture (from the English MDF - Medium Density Fibreboard) dates back to the 60s of the last century, when the manufacturing technology of medium density fibreboard began to be actively used in the USA. And although in the furniture industry of the post-Soviet countries this material began to be used only 30 years later, this did not prevent it from quickly gaining popularity and seriously competing with chipboard and natural wood. Modern technical means allow you to make facades from MDF in any shape and color palette, however, a more important aspect is unique properties material, thanks to which the furniture is able to withstand severe external loads, which is especially important for the kitchen.

For the manufacture of MDF, various waste products from the woodworking industry are used. First, they are processed into fine sawdust, which is subsequently compressed under the influence of high temperature. A special resin is used as a binder, causing minimal formaldehyde emission, which puts this material on a par with ordinary tree in terms of environmental friendliness.

Compared with chipboard, MDF has a denser structure

chief advantage of MDF before chipboard and natural wood, the material is less dependent on the level of humidity in the room. It is known that chipboard loses its shape and strength after a short contact with water. The wood dries out over time, as a result of which cracks may appear on the furniture, which are not always visible under varnish, but are perfectly visible under ordinary paint. In turn, medium density fiberboard is less susceptible to such deformation processes, therefore it is more often used for the manufacture kitchen facades.

Pay attention! The ability of MDF to resist moisture is determined by the density index. On average, the density of such a material from different manufacturers is 700 kg / m³. If it exceeds 1000 kg / m³, then the plate is able to calmly tolerate high humidity in the room without the additional use of moisture-resistant impregnations.

Despite its strength, MDF belongs to soft materials and is very easy to process, which is why furniture makers and designers love to work with it. Having a milling machine at hand, it becomes possible to make almost any profile. If the design of the kitchen involves the presence of semicircular elements, using a press, you can bend the sheet to the desired shape.

Professional production of kitchen MDF facades

The process of manufacturing furniture facades using specialized equipment includes several technological stages:

• sheet cutting;
• surface milling;
• exterior finish.

Cutting sheet material

MDF sheets used in furniture production initially have a large format, therefore they are subjected to additional cutting. Sawing material according to the specified dimensions is carried out on panel saws that can cut at any angle. The cutting depth in such machines reaches 21 cm, allowing you to cut several sheets at once, which is very convenient in case of mass production.

To make an MDF facade with a uniform coating, it is necessary to completely eliminate the presence of micro-chips and other defects that may appear after manual sawing. Modern panel saws, thanks to special discs, allow you to immediately achieve the perfect result, so the end surface does not require serious processing. Before gluing the edges, the facade end is only finely sanded to remove wood dust after cutting.

saw cut sheet material on a sizing machine

Surface milling

If the design of the kitchen assumes the presence of even facades, then there is no need for milling the outer plane. However, very often customers require to produce furniture with original decorative elements What is surface treatment for? cutting tool on milling equipment.

Important! The quality of milling must be very high. Otherwise, after applying a decorative coating, there is a high probability of manifestation and strengthening of all milling flaws.

For the manufacture of decorative facades from MDF, as a rule, special templates are used, according to which the cutter cuts the necessary contour on the surface of the plate. In advanced enterprises, CNC machines are used for such purposes, allowing you to create absolutely any drawing in a matter of minutes.

Milling MDF on a CNC machine

Exterior finish with polymer film

Facade finishing is milestone in the production of kitchen furniture, since the service life of the product largely depends on the quality of the outer coating. MDF can be covered with enamel or polymer film. If it is quite possible to paint the facade at home (this technology will be discussed below), then facing the prepared part with PVC film is available only in the workshop if there is special equipment– thermal vacuum press.

Finishing the facade with a polymer film is carried out in the following sequence:

1. The ends and the outer plane of the part are covered with a layer of glue.
2. The facades are evenly laid out on the table of the thermal vacuum press.
3. A polymer film is laid on top suitable color.
4. A protective cover is lowered onto the table, isolating the parts and the film from external environment.
5. Heating of working space with simultaneous pumping out of air for creation of necessary vacuum turns on.
6. Under the influence of high temperature and negative pressure, the film softens and tightly envelops every detail.
7. At the end of the cycle, the parts are cooled, after which the excess film is cut off along the contour.

Production of facades from MDF on a thermal vacuum press

How to make facades for the kitchen at home

If you have the desire and technical capabilities, you can make kitchen MDF facades yourself. This will require:

• MDF board;
• Circular Saw;
• sandpaper different grits (P180-240, P320-400);
• scotch brite;
• filler for wood;
• primer-insulator;
• polyurethane primer;
• acrylic enamel;
• acrylic lacquer.

Cutting MDF boards

To make facades for the kitchen, you first need to purchase an MDF board. Usually furniture makers use sheets with a thickness of 16 mm or 19 mm - this is quite enough to create reliable kitchen furniture. Of course, you can purchase a sheet and bigger size, however, this does not make much sense, unless such a thickness is needed to implement some design idea.

When purchasing MDF from furniture makers, you can immediately cut it, taking into account the required dimensions. average price such a service is 40-50 rubles. per meter of cutting. If every penny counts, this work can be done independently, for which you need a circular saw.

To simplify the work, it is better to pre-divide the slab into several smaller fragments, from which then cut out the details for future kitchen facades. Despite the fact that MDF is less prone to destruction than chipboard, you should be very careful during the sawing process to prevent micro-chips or at least keep them to a minimum.

In order to make kitchen fronts without distortion, the saw must be moved using a guide structure.

Surface painting

Film cladding, which is performed in the factory, is considered by many to be more resistant to mechanical damage and aggressive cleaning agents. In fact, modern paint coatings are also able to withstand the severe stresses typical of the kitchen, and do not lose their properties over time.

In order for the coating to have a uniform structure and securely adhere to the MDF, painting must be done according to the following instructions:

1. Treat the surface of the part with P180-240 emery to remove the gloss and create the necessary abrasive.
2. Apply the filler and let it dry (drying - 4 hours).
3. Sand the surface with P
4. Apply an insulating primer (consumption - 90 gr./m², drying - 6 hours).
5. Remove abrasive with P320-400 sandpaper.
6. Apply polyurethane primer (consumption - 150 gr./m², drying - 10 hours).
7. Prepare the surface for painting with P 320-400 sandpaper and scotch brite.
8. Apply acrylic enamel(consumption - 200 g / m², drying - 10 hours).
9. Open the facade with acrylic varnish (consumption - 150 g / m², drying - 6 hours).

Advice! It is best to apply primers and paints and varnishes with a spray gun or use special spray containers for this.

The production of painted facades for the kitchen from MDF should be carried out in a clean and dust-free room

Do-it-yourself curved facade manufacturing technology

Sometimes kitchen design involves the manufacture of bent structures, which are made at furniture enterprises using a molding press. To make a bent facade from MDF with your own hands, you must use the following technology:

1. Take a sheet of MDF 9 mm thick and cut out two blanks from it - one for the outside of the facade, the other for the inside. Since the radius is larger on the outside, the outer part should be slightly longer.

1. Make a template for forming a semicircular facade. Any design with a suitable bend radius can be used for this purpose.

1. Mark with inside blanks for cuts that will allow you to bend the sheet. Cuts must be made only at the bend, the distance between them is 5 mm. circular saw should be adjusted so that the depth of cut is 7-8 mm.

1. From a mixture of sawdust and wood glue, make a paste of medium consistency to fill the cuts. You need to rub the paste with a spatula, moving it along the cut from the center to the edge to eliminate air pockets.

1. After filling all the cuts with adhesive paste, install the inner blank on the template.

Curved kitchen facades always look stylish and original.

Working with MDF is easier than with chipboard, since this material does not crumble during cutting and milling. However, make your own beautiful furniture not so easy. Without the appropriate skills and experience, it is possible to spoil the product, as a result of which the expected savings will turn into a loss. Therefore, ordering kitchen facades from professionals may ultimately turn out to be more profitable not only aesthetically, but also financially.

Refinement of MDF boards

Cladding wood fiber boards with sheet materials

Facing materials

The materials used for facing wood-based panels can be divided into three groups:

Paper-based films obtained by impregnating papers with special resins;
- synthetic films;
- paper laminates (decorative paper laminates).

Tile caching

Laminating is a technology for facing wood-based panels, in which a film continuously fed from a roll is rolled onto a surface previously smeared with glue. You can roll the film on both plates simultaneously.

Conditionally distinguish between cold, warm and hot laminating. Cold is used when veneering with non-heat-resistant films, mainly synthetic, using PVA adhesives. The curing of the adhesive usually takes place in a foot with a slight load from above. During warm laminating, the adhesive is applied to a non-cooled (or preheated) surface, which facilitates the evaporation of moisture from it and accelerates the curing process. In this case, the swelling of the plate occurs evenly and its structure will not appear on outside lining. For the final setting of the adhesive, the products are kept in the foot. This method is suitable for facing boards with melamine films, including those with a finish effect. The most common is hot laminating, it is also thermal laminating, in which various adhesives, including urea. Glue and hardener are applied to the surface wood board, and the facing material is rolled onto it by heated rollers.

For lamination, calender presses are used, their combinations with one-story positional short-cycle presses, as well as two-belt feed-through presses. The technological process begins with cleaning the plates from dust in a brush machine. On the intermediate roller conveyor, the base plate is fed into the roller machine, where a hardener solution is applied to one or both layers. After applying the hardener, the board is passed through an infrared dryer to remove the solvent and then fed into a gluer where a thermosetting resin is applied to the evenly dried hardener.

Next, the plate is passed through a roller press, in which a paper-resin film is rolled onto the prepared plate. The rollers are heated with thermal oil at a temperature of about 200 °C. Lined boards after cutting off the film are delivered to the receiving table and stacked in a stack.

When using foils that have already been coated with a dried thermoplastic adhesive or foils with incompletely cured melamine resin, technological process is greatly simplified. There is no need to apply and dry a hardener and to apply a thermosetting resin to the face. The base plate immediately after cleaning goes to the roller laminating machine.

Plate lamination

Lamination in board production is called pressing sheets of the same format onto the surface of the board from impregnated papers with incompletely cured resin. These are usually melamine-containing resins that cure by setting to the substrate in a hot press, so no adhesive is required on the surface of the board. That part of the resin, which is squeezed out on the surfaces facing the gasket sheets of the press, perceives the structure of the latter. By using suitable spacers, it is possible to obtain lined boards with a smooth or embossed surface.

Depending on the purpose of the lined slab, its coating can be single or multilayer. After the final curing, the resin turns into a thermosetting polymer, and the resulting board is composite material, which in structure resembles laminated plastic, only instead of kraft paper a rigid substrate is used, that is, a base plate.

In the past, multi-storey hot presses borrowed from the plywood industry were the main laminating equipment. As the demand for high gloss furniture parts increased, these presses began to use polished steel pans and cool the press plates before relieving pressure. Polished pallets require very careful handling, even sanding dust and fingerprints on them can reduce the quality of the lining. Therefore, the lamination area must be kept impeccably clean, and the staff must work in special clothes and shoes.

The lining cycle in a multi-storey press lasts several minutes, during which time the press plates cool down so that some pallets can be unloaded and others loaded. Due to the need to withdraw hot coolant, and then again bring it to the operating temperature, the energy consumption when using multi-storey presses is quite high.

At modern enterprises, for laminating full-size boards, short-stroke single-span presses are mainly used. Highly mechanized and automated lines based on such presses make it possible to realize a high curing rate of impregnating resins. To emboss the surface in order to obtain a non-smooth, porous structure, the press is equipped with special pallets, a device for quick pallet change is provided.

The pressing cycle for veneering consists of the following steps: depressurizing the press, quickly opening the press, unloading the veneered board while loading a new pack, quickly closing the press, increasing the pressure, holding the pressure.

Typically, standard equipment on such installations makes it possible to obtain a matte facing of the plate. To obtain glossy facings, polished steel sheets are used as pressing surfaces, and a high gloss in a laminated coating can only be achieved in multi-storey presses with cooling of the working plates.