Frames and details of chairs made of curved plywood. Bent plywood Bent glued furniture parts

From such a material as wood, many different items are made. Often among wood products there are bent-glued elements (lamellas). The purpose of these elements is to play the role of furniture parts that contain the operational loads that may result from the use of this furniture. Bent-glued elements (lamellae), already, judging by their name, have a non-rectilinear shape and a certain profile. Obtaining a profile of a certain shape is achieved by processing wood on special machines, usually tape or milling. Bending at a certain angle can be obtained using special technologies for this.

Wood has certain properties. By influencing the material in some way, and at the same time, creating certain temperature and humidity conditions, it is possible to bend a wood blank and get the same bent-glued elements (lamellae) or any other non-rectilinear product.

It should be noted that the process of bending wood products inevitably leads to deformations. Deformation, in turn, generates stretching of the outer layers and compression of the inner layers of the tree. If the forces to fold are too strong, the fibers may break. To prevent this from happening, the workpiece is pre-treated by hydrothermal methods, plus the bending process is fully automated. You can get the same bent-glued elements (lamellas) quite easily using massive and glued wood for this. The gluing process for sliced veneer or plywood is usually carried out in conjunction with the bending process. If we consider the types of wood that are best suited for the manufacture of bent-glued elements (lamellas), these will most likely be hardwoods. That is, wood species such as oak, ash, poplar, linden, beech, birch and others are well suited for these purposes.

The scope of bent wood elements is mainly furniture production.

In particular, bent-glued elements (lamellae) are wide application in the manufacture of beds, sofas, armchairs and other furniture products. These elements are distinguished by good mechanical strength, have an attractive appearance. In addition, of course, a whole range of furniture wooden elements which have a bent shape. These are backs for armchairs and chairs, legs for stools and tables, various shelves and brackets, and others.

22.05.2015

Bent glued blanks are made by gluing veneer packs in heated molds with their simultaneous bending. Under such conditions, the package is deformed and takes the form of a blank, which is fixed as a result of the curing of the adhesive and the decrease in moisture content of the package during hot gluing.
Materials. For the manufacture of bent glued blanks, peeled veneer is used mainly from birch, alder and other hardwoods, less often from wood. conifers. The thickness of the veneer depends on the complexity of the profile, package design, angles and bending radii and is 0.95-2.2 mm.
Most often, lump veneer is used with a width of over 100 mm and a length corresponding to the size of the workpiece. In the manufacture of furniture blanks, depending on their purpose, peeled veneer AB and BB, as well as sliced veneer of I and II grades with a thickness of 0.6-1 mm, facing films based on decorative paper and other sheet or facing materials. Rotary veneer is used for the inner layers III grade. The grade of veneer for the manufacture of building curved glued profiles depends mainly on the calculated resistances adopted for them and, to a lesser extent, on the aesthetic qualities of the structure.
The humidity of the veneer in terms of its deformability should be the maximum allowable. It depends on the required humidity. finished product, corresponding to the equilibrium humidity under operating conditions. The moisture content of the veneer also depends on the type of adhesive used and the gluing conditions. For the manufacture of curved furniture blanks, veneer must have a moisture content of 8 ± 2%, and construction - up to 12%.
Gluing veneer in the production of curved blanks is carried out with fast-curing adhesives, which increases the productivity of the process when gluing blanks of considerable thickness in low-rise presses.
For the manufacture of furniture blanks, urea-formaldehyde adhesives based on resins of the M-70, SFC-70, KF-Zh-F, KF-MT-F, etc. grades are used, and for building materials, phenol-formaldehyde grades SFZh-3013, SFZh-3014, SFZh-3011, bakelite film. The adhesives used with a viscosity of 90-230 s according to VZ-4 according to the recipe do not differ from those used in the manufacture of plywood.
Technological process. It includes the following stages: preparation of veneer, application of glue and assembly of packages, gluing of packages, machining of blanks.
Veneer preparation. The veneer, after sorting by quality and thickness, is cut in accordance with the dimensions of the blanks and the design of the packages. For the manufacture of blanks of a complex profile with a variable cross section, it is cut according to the markup or according to the template in packages, the thickness of which depends on the type of equipment used and the direction of the fibers relative to the direction of the cut or cut.
Veneer packs up to 130 mm thick are cut into circular saws at a cutting speed of 45-55 m/min, feed speed for longitudinal cutting 15 m/min, for transverse cutting - 6 m/min. On guillotine shears of the NG-30 type or paper-cutting machines BRP-4M, the veneer is cut at a speed of movement of the machine carriage of 5.9 m/min. The greatest thickness of the packages when cutting on guillotine shears along the fibers is 90 mm, across - 30 mm, on paper-cutting machines - along the fibers 100 mm, across - 80 mm. In the process of cutting veneer, the dimensions and configuration of the blanks are controlled. Deviations in the length and width of the blanks should not exceed 5 mm per 1000 mm of the measured size.
Applying glue and assembling bags. Glue is applied to the veneer in a glue dispenser, their roller machines KV-9, KV-14. The working length of the rollers of these machines is 900 and 1400 mm, the minimum length of the processed workpieces is 350 and 500 mm. Workpiece feed rate 15 and 30 m/min. Glue consumption, depending on the complexity of the configuration of bent-glued blanks and the quality of the veneer, is 90-130 g/m2.
Preparation for gluing consists in keeping the sheets with the applied adhesive layer or assembled packages for 15-20 minutes, depending on the characteristics of the veneer and glue. The packages are most often assembled manually, which is often due to their design and the use of small-format veneer. The assembly is carried out in accordance with the geometry of the bent glued workpiece and the structure of the veneer package, which is determined by the loading conditions of the parts during operation. The principles of composition of veneer packs also take into account the thermoelastic stresses that occur in hot-glued packs.
The highest strength of the part in one direction is achieved when the number of transverse layers is 8-10% of the number of longitudinal ones. The transverse layers should be placed closer to the center of the section, while the number and location of the transverse layers should ensure the elastic-geometric symmetry of the section. The parallel arrangement of all layers in the package is acceptable in those products whose transverse dimensions are much less than their length and do not exceed 100 mm, for example, a chair leg. For parts working in shear, it is preferable to alternate longitudinal and transverse layers of veneer (for example, for the back or seat of a chair).
Packages are assembled from veneer with a thickness depending on the required radii and bending angles of the workpiece. Such an internal radius of the workpiece is considered acceptable, at which there is no destruction of the veneer wood. It depends on the thickness, species and moisture content of the veneer wood, the design and the bending angle of the package (Table 41).

The use of thin veneer for the outer layers and thick veneer for the inner layers makes it possible to produce bent glued blanks with a small radius of curvature, while reducing labor costs and the consumption of adhesive materials.
To avoid dangerous radial stresses that occur after the release of the pressing pressure on the package, the ratio of the inner bending radius to the outer should be more than 0.5. When assembling packages, it is necessary to maintain their thickness. Deviations of packages in thickness during gluing in rigid molds leads to a very uneven redistribution of pressure over the area of the package.
If the package thickness is less than the calculated one, the punch pressure is transmitted mainly in its center. With a thickness greater than the calculated one, the main force is transferred to the edges of the package (Fig. 80). In the first case, the middle part of the workpiece is excessively compacted, and the edges are under insufficient pressure, and in the second case, vice versa. In both cases, it is impossible to achieve high-quality bonding. The thickness of the packages in the manufacture of bent glued blanks is set, taking into account their compaction during gluing, equal to 7-8%. A variable thickness of the profile is achieved by laying the veneer in an overlapping bag or by using additional layers of veneer (Fig. 81, a). Parts of a small section (chair legs, armrests, hangers, etc. (see Fig. 5, b, 3, n) are made from multiple blanks by assembling packages of veneer of the appropriate format (Fig. 81, b). This allows for more rational use equipment, raw materials, reduce labor costs.In the assembly process, control the consumption of glue, package design.

Gluing packages. When forming curved glued profiles from veneer, uniform pressure transfer to the glued package is very important. Curved blanks are made in presses equipped with molds, usually consisting of a punch and a matrix. If the profile depth is large, which often leads to the use of a complex mold, one mold is installed in the press; if the depth is shallow, the press is equipped with multi-storey molds.
The simplest in design is a one-piece rigid mold. When pressing symmetrical workpieces in rigid one-piece molds, the pressing force P is distributed unevenly over the package area (Fig. 82, a). On inclined or curved sections, it is equal to

With an increase in the angle of inclination, the pressure on this section of the profile decreases and, at a = 90 ° (for example, when pressing profiles with vertical walls), it is completely absent.
Simultaneously with the action of the force P "on the package acts shear force P", tending to move the veneer sheets relative to each other. Sheets are shifted provided that

In the manufacture of asymmetric profiles (Fig. 82, b), the pressing forces acting normally to inclined areas are equal to

To ensure the same pressing pressure on inclined sections of length L1 and L2, it is necessary to orient the mold relative to the direction of the pressing force P in such a way that

The difference in pressing pressure is exacerbated by mold errors and deviations in the thickness of the packages being glued. The uneven distribution of pressure on the package is the main disadvantage of rigid molds and causes uneven quality of gluing and different thicknesses of packages. Therefore, rigid one-piece molds are used only when forming shallow profiles.
Greater uniformity of pressure on the package can be achieved by using rigid molds with a dissected matrix or punch (Fig. 83, a, b). When working according to scheme a, the preliminary formation of the profile and the creation of pressure on the horizontal part of the package 2 is carried out when the plunger 1 moves down, which through the movable base 3 of the matrix 4 acts on the levers 5. The levers are rigidly connected to the side hinged walls 6 of the matrix, providing pressure on the side parts of the package.

When working according to scheme b, the composite punch with the pressing parts hinged on the vertical rod 1 is lowered into the matrix 2, forming the profile of the package 3. parts of the punch 6. Thus, a relatively uniform pressure on the package is ensured.
A relatively uniform pressure on the package can be achieved using multi-plunger presses (Fig. 83, c), each of the plungers 1 of which is equipped with a part of the matrix or punch. In this way, for example, blanks for the walls of half-boxes, legs of stools and chairs, etc. are obtained.
The pressing of bent glued blanks is also carried out in molds with metal tires in the form of tapes 1.5-2 mm thick (Fig. 83, d, e). The tire provides equalization of pressure, which is directed along the radius of curvature. It fits snugly to the package and deforms along with it. Under such conditions, sliding friction between the tire and the outer layers of the package is eliminated, which prevents their destruction. When the package is bent, its neutral axis shifts towards the tire, as a result of which the stresses in the stretched zone decrease, so profiles with smaller radii can be formed using this method.
When gluing in a mold according to scheme d, when the punch 1 is lowered, the profile of the package 2 is formed, and with further tension of the tape 3, the curved section is sequentially crimped with a tape, and the rectangular sections are pressed with side clamps 4. The profile is formed according to scheme e on a rotating punch 1, winding package 2 together with tire 3.
The disadvantages of molds with tires are their short service life, unequal pressure on the package, which is generally absent in straight sections, the impossibility of forming profiles with several bend angles.
The greatest uniformity of pressure is achieved when pressing bent glued elements by the method of elastic transfer of pressure to the package (Fig. 83, e). The shaping element of package 1 of such a mold is punch 2. On working surface the matrix 3 contains one or more flat elastic chambers 4, into which a working fluid (for example, hot oil) or compressed air is supplied under pressure. The device on a matrix of several chambers is effective in the manufacture of complex profiles. Sequential inclusion of chambers from the middle to the edges of the profile ensures its unrestricted formation, prevents the appearance of gaps and folds on the veneer of blanks. Due to the hydrostatic pressure on the package, a high quality of gluing is achieved, it is possible to obtain blanks of the most complex profiles.
Bonding using elastic diaphragms is also carried out in vacuum or vacuum-pneumatic molds (Fig. 83, g). In them, the profile of the package 1 is formed by a rigid punch 2 in the matrix 3. In this case, the package is in a sealed chamber A between the punch and the diaphragm 4. Air is removed from the chamber through channels 5 by a vacuum pump, and atmospheric air on the other side of the diaphragm provides pressure on the package. The advantage of such press devices is their low metal consumption due to the absence of reactions to the press frame. In addition, the curing process of the adhesive during hot gluing in a vacuum is more intensive than when atmospheric pressure, harmful gaseous bonding products (phenol, formaldehyde) are removed from the pressing zone. If the pressing pressure in vacuum (up to 0.1 MPa) is insufficient, additional pressure is created by forcing air with reverse side diaphragm through channel 6.
Molds, depending on the volume of production, the method of heating them, structures are made of steel, silumin, duralumin, plywood boards, wood laminates, plastics. Elastic chambers and diaphragms are made of heat-resistant rubber, silicone and fluoroelastomer. To increase strength and wear resistance, these materials are reinforced with chafer, metal foil. The required pressure on the package depends on the method of its transfer (rigid or elastic), profile configuration. When pressing in rigid molds, the pressure is 1-2 MPa, with its elastic transmission - 0.1-0.5 MPa.
The packages are usually glued together in a hot way, which ensures high productivity of the process and low form changeability of the achieved profile shape. Packages are heated in a conductive way and less often in the field of high frequency currents (HFC). Conductive heating is provided by steam supply to the channels of the mold, tubular electric heaters, also placed inside the mold, electric contact flat heaters in the form of metal strips located on the working surfaces of non-metallic molds. With a package thickness of up to 8 mm, electrocontact heaters are placed on one side, with a larger one - on both sides. Heaters in the form of tapes up to 3 mm thick are made of steel grades 08; 10, brass of grades L62, L68, bronze of grade Br.OF 65-0.85, nichrome of grades Kh15N60, Kh20N80, etc. surfaces of molds in the conductive method of heat transfer to the package 110-135°C.
More effective, especially when gluing thick workpieces, is heating in the HDTV field. This is due to the fact that the temperature across the cross section of the material increases in the same way. It is desirable to glue packages in the HDTV field in non-metallic molds in order to avoid generator power losses. Such heating is used, for example, in the manufacture of a closed profile chair side. The temperature of the adhesive layer during high-frequency heating reaches 100-120°C. The relative cost of the gluing process when heated in the field of HDTV, steam and electrocontact is related as 1.0: 1.05: 1.08.
The duration of gluing the package depends on the method of heating it, the temperature, the working surface of the mold during conductive heating, the thickness of the package, and the characteristics of the adhesive. With the conductive method of heating and the mold working surface temperature of 110-135°C, the specific duration of gluing with urea-formaldehyde adhesives is 0.65-0.5 min/mm, respectively. In the case of electrocontact heating to the same temperatures, its duration is 0.75-0.6 min/mm. The duration of gluing in the HDTV field depends on the input power. For heating, HDTV generators with an oscillatory power of 10-60 kW and an operating frequency of 5-25 MHz are used.
Single-plunger and multi-plunger presses are used as press equipment in the production of curved blanks (Table 42).

Loading packages into the press and unloading blanks from it, especially in the manufacture of their complex profile, large-sized, is usually done manually. In the production of blanks with a simple profile and low requirements for the geometry of the profile (for example, the back of a chair), two or three packages are loaded into each gap of the press.
The gluing area is often organized in such a way that packages at one workplace are assembled simultaneously for gluing in several presses (Fig. 84). Schemes of sections are also proposed that provide mechanized assembly of packages, their transportation, loading into the press, and unloading blanks from the press.

Molded bent glued profiles (corners, channels) are made on production lines based on a caterpillar or roller press through the type.
After gluing, bent glued blanks up to machining kept for 1-3 days. This is determined by the need to relax shrinkage stresses in them, causing their deformation of the workpieces. The deformations are especially significant across the fibers and in the places where the profile is bent. At the initial moment of exposure, the bending angle of the profile increases in comparison with the nominal ones, and then it decreases. The formability of the workpiece after pressing must be taken into account when designing molds.
During the gluing process, the parameters of the gluing mode are controlled. After gluing, the geometrical dimensions of the workpieces, the bonding strength are controlled by determining the shear strength along the adhesive layer, the bending strength of straight sections of the profile and bending (bend) of curvilinear ones.
Mechanical processing of blanks. Machining of bent-glued blanks consists mainly in their trimming or processing along the perimeter, cutting multiple blanks into parts. Trimming is carried out on circular saws or band saw machines, and processing along the perimeter - on milling machines by template. Multiple blanks of half-boxes, rear legs of chairs, etc. are sawn on specialized multi-saw machines with mechanical feed. In the process of machining, the geometric parameters of the parts are controlled and visually - the absence of delamination, cracks in the bends of the profile.
The production of bent-glued veneer blanks is highly efficient. Depending on the type of profile of bent glued blanks, the consumption of dry veneer per 1 m3 of bent glued parts is 1.9-3 m3 (wood consumption for the manufacture of joinery parts of a complex profile reaches 5 m3 / m3), liquid glue - 117-118 kg. On average, labor costs for the manufacture of bent-glued blanks are reduced by 25-35%, and the cost of production (mainly due to a decrease in the cost of raw materials) - by 20-30%.

Wood-laminated boards, which we know simply as plywood, have found their way into the decoration and furniture industry. They have one of the most unique properties with their help, you can create almost any bend. Due to this, it becomes possible to create unique aesthetic designs and efficient use of the material.

Now let's talk about how exactly you can make bent plywood in the industrial production of plywood and independently at home.

Advantages of bent plywood

What is plywood anyway? These are thin sheets of wood (veneer) connected to each other using a special composition. Birch, alder, pine or beech are usually used as veneer.

Due to these features, the material has the following advantages:

High level of moisture resistance. Compared with simple tree the hydrophobicity of plywood is approximately half that. This makes it possible to use moisture-resistant plywood in rooms with increased level moisture and at registration of facades of buildings outside.

There is no warping, and the material is also the least susceptible to decay.

Beautiful appearance with wood texture.

Very easy to use on your own. With such a pliable material, work becomes easy.

Resistant to UV rays, so the material does not fade in the sun.

Low cost. Much wins at its price to natural wood, and also has the best technical performance.

Ease of care. Application possible detergents for cleaning plywood surfaces.

Environmental friendliness. All materials used for the manufacture of plywood are safe for human health. This makes it possible to position a product made of this material even in the child's room.

Abrasion resistance. With constant contact with various furniture, hands or feet does not wear out.

Long service life. Due to all the above qualities, it has long term operation.

You can create smooth shapes and curves. This quality is great for creating unique and interesting designs, which we will talk about further.

Ways to bend plywood

There are two ways to bend plywood, which we will talk about now. Here it is worth giving a little advice: when applying each of the methods, you should not place the top veneer in such a way that the fibers are across the bend, as this may cause a break.

Folding layers when gluing

This technique is commonly used in production environments and its meaning is as follows: Using curved veneer molds that are preheated with steam or electric current. Next, glued and bent into the required shape plywood sheets are placed there, the moisture level of which reaches a level of no more than twenty percent. They are located in them until the glue dries to such an extent that it can perfectly hold the material of a new shape.

At home, it is impossible to find the necessary equipment, but you can do it in a completely different way:

Glue several thin plywood sheets with wood glue.

Bend yourself into the desired position.

Fix along the edges with epoxy mortar.

Wait for complete drying.

The method is quite good, but do not forget that thin veneer should be used for it. If available finished sheet thick plywood, another option should be used.

Bending plywood after it has been glued

A thick sheet is difficult to bend just like that. It must first undergo a special treatment to become softer and more pliable. Only then can the sheet be bent. But first it should be placed in the prepared curved veneer.

Processing may be of the following types:

In factories, special industrial steam installations are used for such cases.

As for home conditions, you can use the steam from the kettle for small parts or a household steam generator.

You can also steam with a kettle.

If the plywood is large, then it should be placed in hot water in order to give the sheet greater elasticity. In this case, it is important to prevent delamination of the sheet.

Here it is better to use three methods: Leave the plywood in the water for half an hour, and then move it to a rigid blank and leave it in this position for a week. Wet the workpiece with plenty of water, bend it a little and iron it with an iron. Then again wet, bend and remove all the water. And do so until the desired shape is reached. You can also warm up required state in an oven, but cracks may appear on the material when using this method.

After processing is completed, plywood can be bent using the following methods:

Place it in the wireframe template. This should be done very carefully and reliably, but, first of all, the frame should be made, which will require a little more time and effort. In order to fix the product, it is better to use spacers and a belt system.

Use steel strip. It should be tied to a sheet of plywood and bent into the desired shape. At the same time, the metal will perfectly keep the shape and will not let it lose. Next, you just need to leave the finished structure until it hardens completely.

The use of propyl. This will be especially useful when using a thick product. Several incisions should be made at the site of the intended bend, which will make it possible to make the bend more easily. Then the workpiece is installed in the required position, and the resulting gaps are clogged with adhesive.

Why are these folding methods used?

With the help of the above methods, you can give smoothness to the forms. They will retain their position even after the material dries. Thus, it became very easy to make arches for doors and rounded shapes of walls. But especially wide bent plywood used in the manufacture of furniture.

This makes it possible:

Do minimum quantity corners that could cause injury. This is especially true for those rooms in which there are constantly children. Because their restlessness very often leads to contact with corners.

Make the interior more aesthetic and meaningful. Since it is more interesting for the eyes to look at the smooth lines of transitions, and not their sharpness. This design move helps to calm down and improve the overall mood.

Making it more solid finished construction and getting rid of the very congestion of details for fixing. This allows you to greatly enhance the strength and reliability of the finished structure.

Plywood sheets are really great material suitable for both decoration and furniture making. Its comparative cheapness and improved technical properties made it a worthy competitor to plain wood. It is noteworthy in particular that plywood has an excellent ability to bend into a variety of shapes, which wood cannot boast of. Thanks to this, the interior is filled with special aesthetics.

Despite the huge variety building materials produced by modern industry, their new modifications and varieties appear every year, which are distinguished by an excellent set of physical and technical parameters and unique specific properties.

One of them is flexible plywood, which has the advantages natural wood and characterized by extraordinary flexibility, not typical for other woodworking products. The reason for this flexibility lies in the raw materials used. This is the wood of tropical trees, the wood of which is characterized by low density.

These include:

Ceiba (Ceiba). Area of origin: Africa and the Middle East. Features of wood: light cream. Light weight, soft and durable. It tolerates gluing, painting, polishing and.
Sumauma, Parika, Faveira. Area of origin: Africa and South America. Features of wood: from creamy white to light brown and pinkish. It resembles ceibu in structure and composition.
Keruing. Area of origin: Indochina and countries of Asia Minor. Features of wood: red or red-brown. Very strong, resinous and hard, can be used in high humidity conditions.

AT recent times flexible plywood made from birch veneer has also become widespread. She owes her special qualities special structure layers with a cross arrangement. The main advantage of this flexible type is its availability and lower cost compared to exotic counterparts.

Varieties of flexible wood:

Today on sale you can also find the so-called bent or bent plywood, made from thin veneer, the sheets of which are glued together during the production process according to the sketches of the future product. in the manufacture of furniture. Due to its elasticity, strength and ease of processing, this material is very convenient for creating pieces of furniture of the most inconceivable and original shapes.

Bent plywood is made from peeled veneer of birch, larch, beech, pine and even MDF. For facing its surface, veneer is used from valuable wood species, such as walnut, mahogany or oak. Due to the use of such a spectacular cladding, bent plywood products look very expensive and elegant.

The advantages of this material include:

Great variety of shapes.
Homogeneous structure.
Resistance to abrasion and mechanical stress.
Spectacular appearance and decorative effect.

Production and specifications

In the process of manufacturing flexible transverse plywood, layers of wood (at least 3) are interconnected with a special adhesive composition, after which the sheets are heated and pressed at a certain temperature. As a result of this processing, a unique and unusual material, with its high strength and lightness, it has excellent elasticity and resilience.

Technical parameters and properties of Asian plywood:

Technical parameters and properties of African plywood:

Thus, evaluating flexible plywood on a five-point scale, it can be assigned marks of "five" in the categories "practicality", "external attractiveness" and "reliability". As for availability and price range, here is this finishing material deserves a "troika" because of its high cost and "exoticism". The exception is Chinese-made flexible plywood, which combines all of the above advantages and has an affordable price.

Application and products

Curved plywood is most widely used in the furniture industry. In particular, kits for children's rooms are made from it. The main advantage of such products is their original appearance, high strength and the absence of sharp edges and corners that can injure the child. Such plywood is not suitable only for. For these purposes, special ones are used, such as, and others.

In addition, it is the basis for the manufacture of so-called bent glued elements and products, which include:

Rocking chairs.
Office chairs, furniture for cafes and restaurants.
Elements upholstered furniture and facade elements of cabinet furniture.
Flexible bed bases, called "latoflexes" or "lats".
Decorative and constructive components of mirrors, bedside tables, cabinets, etc.

Using the previously used five-point scale, curved plywood products can be assigned "five points" for functionality, decorativeness and ease of use. And for the cost and complexity in manufacturing, they deserve a rating of "four", which confirms their high quality, originality and uniqueness.

Press for the production of plywood products:

Bending plywood at home

Bend the plywood, giving it the original and unusual shape possible at home. To do this, it must be placed in appropriate conditions, with a certain temperature and humidity.

The main methods used to create bent structures from this material:

Steaming.
Gluing.
Creation of cuts.
A combination of the above processing methods.

To give plywood elasticity, you can do the following:

By immersing it in water heated to +95 ⁰С. In this case, water of the required temperature is poured into an open container of the appropriate size, after which sheets of plywood are lowered into it. Time spent in water: 5 to 30 minutes. Then the wood begins to gently bend. First, a minimal bend is made, and the workpieces are again immersed in hot water, leaving it there for another half hour. After that, the manipulation is repeated until the part acquires the desired shape.
Having processed it with hot steam. For this purpose, you can use a regular kettle or iron with a steam function. But the main difficulty of this process lies in the fact that the effect of steam on the material must be constant and long enough, and at home it is very problematic to achieve this. In this situation, it is more convenient to work with an iron. The workpiece is wetted and ironed with a well-heated iron. Then the plywood is gently bent to a small radius. These steps are repeated several times until the desired bend is obtained.
Soak it in warm water. The most inconvenient way, because of the duration and low efficiency.

The above methods are well suited for self-manufacturing small pieces of plywood. To bend a sheet big size, it is necessary to make cone-shaped cuts in the form of strips in it, while acting as carefully as possible to prevent the appearance of cracks and chips.

For cutting cuts, it is better to use an electric jigsaw with a cutter. The depth of cuts - with a sheet thickness of 4-5 mm - no more than 2 mm. Quantity - in accordance with the angle of bending. After sawing, the plywood is clamped on the template used and with epoxy glue. The drying time of the workpiece is about a day.

So that as a result of arching you get beautiful and original elements high quality, the following points must be taken into account:

The value of the transverse radius of wood fibers should be much smaller than the longitudinal.
Manufactured parts must be stored at a humidity not exceeding 9-11%.
Bending of steamed or heated workpieces must be done while they have not cooled down.

On the picture - original shelf bent plywood

Do-it-yourself bent plywood

After undergoing preliminary preparation, plywood can be bent in accordance with the given patterns.

At home, this can be done like this:

A load is attached at the bend, and the edges of the sheet (supports are placed under them) are pulled together with a rope.
Plywood is fixed with tape or rope.
The function of a template can be performed by any structures that have the desired angle of curvature and sufficient strength. For example, fiberboard sheets cut to the appropriate shape and size.

When making a large part or a non-standard shape, it is better to use as a template steel sheet. At the same time, plywood bending must be done simultaneously with the workpiece, firmly fastening the sheets together. It will be possible to separate the template only after the design has dried well.

You can also bend plywood by gluing its layers. To do this, a template is first made, and thin layers of wood are laid on it, bending them along a given radius and smearing them with an adhesive (PVA or epoxy).

In this case, each subsequent layer must be laid on the previous one with alternating direction of the fibers. After drying, the edges of the part are processed grinder to remove bumps and smudges of glue.

How to bend plywood will tell the video:

Curved wood blanks are often used in the manufacture of furniture, arches, stairs, load-bearing structures. Although it is difficult to make bent parts at home, it can be done.

There are several methods for producing bent wooden products. One of them - bent parts are cut from a single piece of wood. In this production, high costs are obtained, parts can be fragile, since often the cuts are made across the fibers, large structures basically impossible to make.

Bent structures can also be obtained by softening wood by boiling or steaming, followed by fixing and drying. At home, it is almost impossible to make bent blanks in this way.

The most commonly used method for producing bent wooden parts today is gluing strips of wood on a template with their further drying. We will consider this technology in more detail, as the most affordable and allowing to obtain, in the end result, high quality.

For curved blanks, prepare a wooden veneer of the required width and length. The number of strips is determined by the thickness of the product and veneer, which can be determined from the following table:

If it is impossible to buy veneer, then you will have to make it yourself by sawing the wood blank of the required dimensions on the machine:

At the next stage, apply glue to the strips with a roller and collect them in a bag, fastening everything with tape. Glue is better to take synthetic - urea.

Fix the package with clamps on a pre-prepared template - wooden or metal. Start fastening from the middle, placing wooden pads.