What is plywood made from? How to make the best plywood in Russia What wood is plywood made from?

Application

Homemade all-terrain vehicle "Karakat" with a plywood body

Insulating products in electrical engineering.
In shipbuilding for stern tube bearings, bushings and liners for conventional bearings (anti-friction, self-lubricating material), gears and other machine parts (structural material)

Classification

Plywood is called longitudinal if the fibers in the facing layers are directed along the long side, otherwise - transverse

Plywood made from both hard and soft wood is available in several types and grades, which differ in purpose, service life, appearance and cost.

By purpose - construction, industrial, packaging, furniture, and structural.

By type, plywood is often divided into two popular types - FC (moisture resistant) and FSF (high moisture resistance).

By type of processing - laminated.

By appearance (determined by the number of knots per square meter of the surface of the outer veneer layer): E (elite), I, II, III, IV.

According to the material from which it is made

Coniferous plywood (made from veneer of coniferous trees: larch, pine, fir, spruce). Sometimes cedar veneer is used to make plywood - such plywood is used for decorative purposes. For coniferous plywood, it is mandatory to contain coniferous veneer in the outer layers - the inner layers may contain deciduous wood veneer.
Birch plywood (made from birch veneer) has become widespread in almost all areas, but due to its relatively higher cost in construction it is not used as widely as coniferous plywood.

By number of layers

Plywood layers

three-layer
five-layer
multilayer

Basically, plywood sheets have an odd number of veneer layers: in this case, the veneer is located symmetrically relative to the middle layer. If there are four layers of veneer in plywood, then the central layers are placed and glued perpendicular to the outer ones, which increases the overall strength and resistance to deformation.

By impregnation

Moisture-resistant plywood is a material treated in a special way to increase moisture resistance. Lamination can help maximize the moisture-resistant characteristics of plywood.

FSF (plywood made using resin phenol-formaldehyde glue). This plywood is characterized by relatively high wear resistance, mechanical strength and high moisture resistance. FSF is one of the most popular types of plywood, used in construction, manufacturing, and roofing.
FC (plywood obtained by gluing veneers with urea glue). Having less moisture-resistant characteristics, FC is used mainly for interior decoration, in furniture production, in the manufacture of wooden containers, and when working with indoor structures.
FB (plywood impregnated with bakelite varnish, subsequently glued together). This type has maximum resistance to aggressive environments and can be used in tropical climates, high humidity and even under water.
BS (plywood impregnated with bakelite glue, S - alcohol-soluble). This plywood has fantastic properties - ultra-high strength, resistance to aggressive environments, flexibility, elasticity, waterproof, does not rot, does not deteriorate. It is also called aircraft plywood because it was previously used only in aircraft and shipbuilding.
BV (plywood impregnated with bakelite glue, B - water-soluble). This plywood has the same properties as the previous one, with the exception of moisture resistance, because... The glue used when gluing the layers is water-soluble.

By type of surface treatment

NSh - unsanded plywood
Ш1 - material, polished on one side
Ш2 - material polished on both sides

Types and grades of plywood

Currently, GOST standards provide for the presence of five grades of plywood, which differ mainly in the presence and number of permissible processing defects.

grade E (elite). Defects are not allowed, except for minor random changes in the structure of the wood;
Grade I. The maximum length of warping or cracking for Grade I plywood should not exceed 20 mm;
grade II. Cracks up to 200 mm, wood inserts, glue leakage up to 2% of the total area of the plywood sheet are allowed;
grade III. Up to 10 wormholes are allowed. per square meter with a diameter of each no more than 6 mm; the total number of listed defects cannot be more than 9;
grade IV. Grade 4 plywood is extremely low quality. Such plywood may have the following defects: partially fused and fallen knots - without limitation; wormholes with a diameter of up to 40 mm without limitation; defects in sheet edges up to 5 mm deep;

Manufacturing technology

“Cutting out” a sheet of plywood

The veneer is subsequently cut, dried, sorted, and collected into bags, that is, the veneer is placed in such a way that the direction of the fibers in adjacent layers is mutually perpendicular, the number of layers is odd, and each even sheet is coated with glue on both sides. These bags are then pressed and heated in a press to create plywood, which is then cut into shape and packaged into bundles. The plywood can then be sanded and laminated with films, resulting in sanded and laminated plywood.

Production in Russia

Plywood in Russia is produced in the following main formats: 1525x1525, 1220x2440, 1500x3000, 1525x3050 mm.

Plywood production in Russia (million m³): 2002 - 1.8; 2003 - 2.0; 2004 - 2.2; 2005 - 2.6;

Plywood production in Russia is mostly located in regions rich in forest resources. The main share of production falls on enterprises of the Northwestern Federal District - about 35% of total production. In 2005, exports amounted to 1.5 million m³, that is, about 60% of all plywood produced in the country.

Notes

Literature

Grigoriev M. A. Materials science for joiners, carpenters and parquet workers: A textbook for vocational schools. - M.: Higher School, 1989. - 223 p. - 100,000 copies. - ISBN 5-06-000345-0
GOST 3916.1-96 General purpose plywood with outer layers of hardwood veneer.
GOST 3916.2-96 General purpose plywood with outer layers of softwood veneer.
GOST 13913-78 (GOST for chipboard)

Links

Wikimedia Foundation. 2010.

Synonyms:

Did you know that Russian plywood is used in the production of German cars? Yes, Mercedes and Volkswagen use our birch plywood. It is also used in the production of furniture, children's playgrounds and even gas supertankers. I visited one of the largest plywood mills in Russia in the Vologda region, whose products are exported to 70 countries. They produce high-quality plywood for various purposes. Now I will tell you how the best plywood in Russia is made.

The SVEZA Novator plywood mill is located in the village of Novator, Vologda Region, not far from Veliky Ustyug. It was founded before the revolution, in 1910. Now it is a huge modern enterprise.

About 3,000 people live in the village, most work at the plywood mill, many for several generations already.

At the factory entrance, everyone is required to blow into a straw. This applies to absolutely everyone, even bloggers. We're okay, we can go.

You can see from the notice board that life is in full swing at the factory. A brief retelling of what is written here: the company’s products are now supplied to Argentina, the struggle for quality, rewarding front-line workers, compensation for food during night shifts, prospects for young people, a social package that includes voluntary health insurance, vouchers to sanatoriums and children’s camps, free transfer to and from work, firewood at a reduced price and financial assistance.

Before heading around the plant, we undergo safety training and sign in a special log. Manufacturing is a high-risk area, especially plywood.

You also have to change clothes - a cap on your head, special boots on your feet, goggles on your eyes, earplugs on your ears, and a bright vest. Now you can go to production, of course, with accompaniment.

On the way to production we stop at the factory museum. The curator of the museum, Svetlana Nikolaevna Belykh, talks in great detail and with enthusiasm about the past, present and future of the plant. The plant was founded by Ivan Yakovlevich Lvov. The place for the construction was chosen ideally: nearby there was cheap timber and a river along which logs were delivered by rafting, bricks were being made nearby, and there were men with hands and heads in the villages nearby. The name “Novator” fully reflected the essence of the production - in these parts it was the first plant for the production of plywood.

After the revolution, the plant is nationalized, but this does not benefit the common cause. The plant stops operating at a time when the country really needs plywood. The authorities turn to the founder of the plant. Founder Ivan Yakovlevich becomes director of the plant and resumes its work. Later, Lvov works in the forest industry of the USSR, Novator continues to work without him.
Lest you think that plywood is a frivolous material, let me remind you that airplanes were built from plywood. Aviation plywood was glued from especially thin veneer using alcohol-containing glues. Also, many car body parts lack metal. made from plywood.

When used correctly, plywood is a unique construction material. Now the company, in addition to regular moisture-resistant plywood, also produces special types of plywood, for example, lined with aluminum or anti-slip abrasive material. By the way, formwork for monolithic construction is also made from laminated plywood.

There are also exotic plywood options that are produced from our plywood abroad. They take our birch plywood, glue a thin layer of valuable wood on top - expensive plywood is ready for furniture or flooring.

After the introductory tour, we head to production. It begins with the timber exchange - here the acceptance and storage of raw materials is carried out. Plywood is now produced exclusively from birch. Deliveries are made by road transport. To ensure that raw materials do not deteriorate, snowing is actively used in northern industries - the wood is stored covered with snow and wood chips, in this form it does not deteriorate and does not dry out until mid-summer. I note that the birch growing in the north is denser and harder than in the central part of Russia, so the quality of the raw materials here is very high.

From the lumber yard, logs are lowered into pools of hot water using cranes. This is necessary so that the wood becomes more plastic.

From the pool, the logs are fed for debarking and bucking - the bark is removed from them and sawed to a certain length.

All these operations are carried out automatically. This area is noisy, the logs roll around like pencils.

Then the most interesting part begins: the logs, cleared of bark, are fed to the peeling line.

The logs are fixed in a peeling machine, spun at high speed, and then a thin layer of veneer is cut from them with a knife. The process is very similar to sharpening pencils in a sharpener, only the knife is much larger and spans the entire length of the log. A long sheet of veneer comes out of the machine.

The veneer is cut into equal pieces and stacked.

Don’t forget, our veneer is raw, its humidity can be more than one hundred percent. Therefore, the next operation is drying. Raw veneer enters the roller dryer, and its output moisture content is about 6%.

Bundles of veneer are moved from place to place by forklifts.

Pay attention to the bright blue lights on the forklift - their beams serve to indicate the trajectory of movement. Safety comes first.

Dried veneer needs to be sorted. Some will go to the outer layers, some to the inner layers, and some to merging and repairing.

On the splicing line, small pieces of veneer are made into format veneer. They are spliced by gluing a special thin thread.

Another interesting topic is veneer repair. Wood is a natural material, it contains knots that negatively affect the strength and appearance of plywood, and may even fall out. Therefore, they came up with the idea of cutting out the knots and replacing them with patches of healthy veneer. Patches can be oval or butterfly shaped for better adherence.

This process is automatic. The equipment is Finnish, but completely Russified.

It looks very impressive and allows you to greatly improve the quality and grade of products.

Next, the veneer sheets need to be coated with glue. Resins are used as glue - urea in the production of moisture-resistant plywood of the FK brand and phenol-formaldehyde in the production of plywood of increased moisture resistance of the FSF brand.

“Sandwiches” of several layers of veneer are fed into a giant multi-bay press, where the plywood is glued under pressure and temperature.

If you glue a special film to the surface of the plywood, you get laminated plywood. This plywood is widely used in the construction industry and in the production of vehicles.

In terms of quality, plywood produced by the SVEZA Novator plywood mill is highly rated not only in Russia, but on the world market.

In the near future, the plant's capacity will increase; work is currently underway to modernize and expand production.

We visited the plywood mill as part of the “Discovering the Silver Necklace” expedition. I really like visiting various factories and combines. This is real production and a real economy. I wish prosperity to the company and all its employees!

Many thanks to the press service of the Sveza company and the tourist information center of the Vologda region.

How is plywood made? Such a question as the production of plywood is of interest to many builders and people who want to build their house or other premises using very environmentally friendly materials.

Stages of plywood production

The production of plywood begins with the selection of logs from felled forest (high quality, absence of butt parts, presence of a clean trunk without various molds). In Russia, trees such as fir, pine, spruce, cedar (coniferous) or birch (the most suitable and affordable option among deciduous trees) are taken.

The next stage is the delivery of wood and processing of the trunks from bark and branches, which are subsequently steamed in water. High temperature and moisture weaken the bond between the fibers. Steaming wood in water occurs in two ways: at a temperature of 30-40 degrees. (soft mode) and at 70-80 degrees. (hard mode). Without steaming the logs, dry wood cannot be processed. The logs are clamped from the ends on the peeling machine, and rotation begins at a fairly high speed.

A peeling knife, as long as a tree ridge, peels off a thin layer of fibers from it, pressing against the log. The surface of the block is the front side of the veneer, and the side of the veneer that is turned towards the block is the left back. Peeling waste is used for secondary raw materials such as particle boards. The resulting long strips are subject to straightening, cutting and drying.

This is how the main component is made, which is called peeled veneer. The veneer yield is maximum. Defective moments of sawing can be called a miter cut (the saw is installed incorrectly or the ridge is placed incorrectly on the conveyor), flakes and bevels (all this is the result of the fact that sawing was carried out by weight), and the wrong length of the block (a consequence of the miter cut).

In the next stage of plywood production, stacks begin to form (the veneer is selected in a certain way: low-quality sheets are stacked on the inside, and good ones on the outside). Separate the right (front) and left (back) sides. The quality of the right side is much higher than the left.

One of the most important operations in this process, because this is how the grade of plywood is determined. The stack is disassembled again and the surface of the sheets is already covered with glue. The adhesive layer is applied one-sided or two-sided (depending on the machine) on glue-applying machines. The pressing stage makes it possible to remove excess air and glue between the sheets. High temperature affects the quality of veneer bonding, thereby forming a plywood sheet. The final stages of the process are cutting the plywood to the desired format, sanding the sheets and sorting the plywood sheets.

The products are packaged in packs, but the main requirement is that the front layer must be placed inside. The process of “How plywood is made” is quite technological and lengthy, requiring strict control at each stage of production.

Plywood is a versatile material that is used for various purposes almost everywhere. Externally, plywood looks like rectangular sheets of certain sizes of varying thickness, consisting of many layers (at least 3) of wood fiber raw materials. Plywood can be made from wood or tree veneer.

Most often, plywood is made from veneer, the layers of which are laid perpendicular to each other and glued with special compounds. This manufacturing technology provides excellent strength and wear resistance, and also increases the material’s ability to resist moisture penetration.

Types of plywood

There are many types of plywood available; it can be moisture-resistant, laminated, made from different types and types of wood, and also have different thicknesses and purposes. How do you determine the type of plywood based on the material? In this case, attention is paid only to the outer layer of plywood, without taking into account the internal ones.

Depending on the type of raw material, the following types of plywood are distinguished:

birch;
coniferous;
combined.

Birch plywood made from veneer of deciduous wood (birch). This veneer has a uniform, more homogeneous structure and good density (about 650 kg/m3). Birch veneer plywood is much stronger than its counterparts made from other materials. The difference in strength sometimes reaches 20%.

However, the cost of birch plywood is slightly higher than that of its analogues. This is explained by the lack of natural resins in birch veneer, which means additional compounds are required to create good quality plywood. Birch plywood has become quite widespread. It is used in the construction of private houses, for packaging transported goods, ship and carriage building, as well as in many areas of the automotive industry.

Softwood plywood cheaper than birch. In Russia, coniferous plywood is usually made from pine and spruce bark. This plywood is lighter and has an interesting appearance due to the wood pattern. However, coniferous plywood is less durable than birch plywood. Coniferous veneer contains natural resin, which contributes to a longer service life of the material.

Natural resins protect plywood from dampness and rotting. Coniferous plywood is in greatest demand in individual housing construction, as well as in the field of interior design and the creation of decorative elements.

The next type of plywood is combined . This material consists of both birch and coniferous wood fibers. It combines the advantages of birch and coniferous plywood. Combined plywood is similar in strength and technical characteristics to birch plywood, however, its price is slightly lower. Combined plywood is widely used in construction, furniture production and packaging.

Types of plywood by adhesive composition

The next aspect by which plywood is divided is the type of composition used for gluing the layer.

Depending on the adhesive composition, plywood can be:

FBA. This plywood is produced using albumin casein glue. FBA plywood is an environmentally friendly material and is not waterproof. This plywood can be used for any purpose at low humidity levels.

FC. FK type plywood is produced with a urea adhesive composition. Plywood has low moisture resistance. The raw materials of FC plywood do not emit harmful substances, the material is absolutely environmentally friendly, so it can be used for interior work in residential premises and children's institutions.

FKM. In the production process of this type of plywood, melamine glue is used. Plywood has average moisture resistance. The adhesive composition contains a small amount of harmful substances. FKM plywood can be used in conditions of low humidity levels and where there are no strict restrictions on the toxicity of materials.

FSF. FSF type plywood has excellent moisture resistance properties. However, in its production a phenol-formaldehyde adhesive composition is used, which contains a fairly large amount of harmful substances. The use of FSF plywood in residential premises, as well as for furniture production, is highly discouraged due to the high risk of harm to human health.

FB. This type of plywood is produced by impregnating veneer sheets with bakelite glue. FB plywood has excellent moisture resistance and is also able to “work” under conditions of exposure to aggressive environments. This plywood can be used in difficult climatic conditions (at low or high temperatures); it perfectly withstands the effects of sea water, various microorganisms, acids and alkalis. In turn, bakelite plywood is divided depending on the composition of the resins (FBS, FBV) and the type of sizing.

FBS bakelite plywood is impregnated with alcohol-soluble adhesives, has high moisture resistance and comes in the following types:

FBS bakelite plywood is the highest quality class of this material due to the impregnation of all layers with bakelite alcohol-soluble glue;
FBS1 plywood is of slightly worse quality. The production technology of this plywood involves coating, rather than impregnation, of veneer layers;
class FBS1A has the lowest quality among bakelite plywood with alcohol-soluble adhesives. Here, only the longitudinally located layers of veneer are coated with an adhesive composition.

The next subtype of bakelite plywood is FBV , made with water-soluble adhesives. FBV plywood comes in two types: FBV (where the inner layers of veneer are coated, and the outer layers are impregnated with adhesives) and FBV1 (where all veneer layers are only coated with adhesives). The main advantage of such plywood is its excellent strength characteristics.

Types of plywood by processing method

The next criterion for grouping plywood is the method of surface treatment.

According to the surface texture of plywood, there are:

Laminated. To do this, plywood is covered with special waterproof films. Laminated plywood is widely used for trim and upholstery of vans.
Polished on one side.
Polished on both sides.
Unpolished.

On the website portal you can buy any types of plywood, as well as look at photos of samples and compare prices from suppliers.

Classification of plywood by purpose

The scope of application of plywood (laminated, sanded, moisture-resistant and other types) is not limited to construction; due to its properties, the material is extremely in demand in various fields.

The website portal offers the following classification of plywood by purpose:

Ship's. For the finishing of shipping vessels, only the highest quality types and grades of moisture-resistant FB plywood (on bakelite glue) are used, which work well in conditions of high humidity and aggressive environments.

Furniture. The types of plywood used for furniture must be environmentally friendly, wear-resistant and durable. As a rule, combined FC plywood is used for furniture.

Construction In the construction industry, as a rule, grades 3/4 and 4/4 birch plywood are used. These types of plywood can be used for floors, walls and other structures as a rough finish.

Aviation. For these purposes, FSF grades of plywood are used. This plywood has excellent technical characteristics and is ideal for such complex and critical areas of activity as aircraft, ship, railcar and automotive industries.

Formwork. To create the formwork, laminated FB plywood is used, which has excellent characteristics in terms of moisture and wear resistance, strength and exposure to aggressive environments.

Decorative. FC plywood is used for finishing the premises. This type of plywood must have excellent characteristics of the outer layer (flat surface with a textured pattern). This type of plywood is usually made from valuable wood or premium wood.

Automotive. For cars, as a rule, FSF type plywood with a laminated or mesh-ribbed surface is used. Plywood has high strength, moisture resistance and durability. It is used for covering all elements of a truck body (walls, floor, doors, ceiling).

Plywood: assortment, characteristics

Currently, plywood is produced in five grades. The technical characteristics of each type of plywood are strictly defined in the current GOST.

Plywood varieties:

Grade 4. This type of plywood is the cheapest and lowest quality. Grade 4 plywood sheets may have multiple wormholes, uniformity defects (fallen knots) and uneven sheet edges (depressions up to 0.5 mm). This type of plywood is used for interior rough finishing. The most common area of application for this type of plywood is the production of various packaging and packaging.

Grade 3. Grade 3 plywood can also have wormholes, but in strictly limited quantities (no more than 10 pcs/sq.m.). The size of wormholes is also limited (the diameter should not exceed 6 mm), and the number of all defects on a sheet of plywood should be less than 9. Grade 3 plywood is also used for rough finishing of premises. However, it is permissible to use this type of plywood in fine finishing work, provided that paint and varnish compounds are applied to the surface of the sheets to hide defects in the material.

Grade 2. Plywood may have the following defects: cracks no more than 20 cm, areas with leaked glue (if the area of the area is up to 2% of the total square footage of the sheet), wood inserts. This plywood, like grade 3, is used for rough and fine finishing for painting.

Grade 1. Defects allowed on grade 1 plywood are cracks and warping less than 2 cm in length. Grade 1 plywood is used in construction for fine finishing inside and outside the building.

Variety E. Plywood E belongs to the elite grade. Grade E plywood must clearly comply with the characteristics stated in GOST, namely: not have wormholes, cracks or other defects, except for random deformations in the structure of the wood itself. Elite grade plywood is the highest quality and most expensive. Used for fine finishing.

The construction portal site will help you find different varieties with delivery to the site.

Each building material has some kind of classification - division according to a number of technical characteristics, the totality of which determines the advisability of its use for solving some particular specific problems. Plywood in this regard is no exception - quite a lot of its varieties are currently produced and different types are used for different purposes. To determine what type of plywood is needed in a particular case, you need to know the basic criteria by which it is classified.

Type of wood for making plywood

The very first sign by which this material is divided into different types is the type of wood that was used when cutting the veneer. Its production is mainly carried out from birch or coniferous species - fir, pine, spruce. In practice, both types are often used, then the type of plywood is determined by the material of its facing layers. So, if the core is made of softwood, but the outside is lined with layers of birch, then such plywood will be called birch plywood. Since birch wood is relatively expensive compared to coniferous species, most of the plywood produced in our country is coniferous plywood, and most birch wood has exactly this structure - its middle is made of veneer cut from pine or spruce.

In some cases, to improve the aesthetic properties of the product, the outer layers are made of more noble types of wood - for example, cedar. Such products are used purely for decorative purposes; they are used to make furniture and are used in interior decoration.

Number of veneer layers

The second criterion is the number of veneer layers. It starts with three, and it is always odd. This is explained by the peculiarities of plywood production - to increase the mechanical strength of the sheet, the direction of the fibers of the veneer sheets during laying alternates, and the odd number allows you to maintain the same appearance on both sides. The exception is the four-layer one - in it the direction of the fibers of the two inner layers coincides, and the outer ones are laid perpendicular to the inner ones. In plywood factories, the required plywood thickness is achieved only by joining the required number of layers of veneer.

Glue

The third important criterion is impregnation or glue. Strong, wear-resistant plywood is obtained by using an adhesive composition based on formaldehyde resins. This is FSF plywood, the price of which is relatively low, which makes it a very popular material in the construction industry.

How to make plywood

FC plywood is impregnated with urea glue. It has less moisture resistance than FSF, which limits the possibilities of its use for exterior work, but it is more environmentally friendly, which allows it to be used for interior decoration. Note that FK plywood is also slightly cheaper than FSF plywood. There are many other types of impregnation designed to create plywood used in harsh climates or high humidity, but these two are the most popular.

Plywood is an artificial material made from several layers of veneer of various types of wood. In this case, adjacent sheets are positioned so that the arrangement of the fibers in them is perpendicular: this increases the resistance of the material to external mechanical influences.

What is plywood

Section of a plywood sheet

This material is classified according to the following parameters:

According to the material from which the outer layers are made. In accordance with this, a distinction is made between birch, coniferous, combined and laminated plywood.
According to the degree of water resistance, plywood is distinguished, the layers of which are connected to each other using urea resin (used only for products located indoors), phenolic resin (plywood products of this type can also be used outdoors), bakelite resin - such products can be used in particularly heavy conditions, including in sea water, in the tropics, etc.
According to the type of mechanical processing: unsanded plywood is produced, as well as plywood sanded on one or both sides.
By the number of layers: single-layer plywood has no practical use, so material is produced with the number of layers from 3 to 23.

Consumer properties

Various types of plywood

The material largely determines the machinability and performance properties. Birch plywood is considered one of the highest quality materials, which is explained by the good physical and mechanical properties of the original veneer, as well as its beautiful texture. Coniferous wood is produced mainly from pine, which also results in its positive features: light weight and visual attractiveness.

Plywood: wood type, number of veneer layers, glue

Therefore, products made from pine needles are often found in homes and cottages.

In the production of combined plywood, layers of coniferous and birch are technologically combined. As a result, the cost of the finished product is reduced, and the performance characteristics remain at the same level. As a result, the combined version is used for finishing sports equipment, gymnastics and training rooms, as well as in furniture production.

Laminated plywood has particularly high strength indicators, in particular, resistance to external aggressive influences of chemical environments. This type of material in question is also characterized by increased resistance to temperature changes, which leads to the main areas of its application. Laminated plywood is used to cover the internal surfaces of cargo transport vans, and is also used to make highly resistant formwork for concrete.

The environmental friendliness of plywood is assessed by the amount of residual formaldehyde in the product: a product of class E1 can be used for subsequent contact with food, but class E2 cannot.

Household use

The quality of its surface often depends on the material: for example, for birch plywood the number of knots per unit surface area of the sheet is significantly less than for that made of pine veneer. In accordance with this, plywood is distinguished:

first grade, the surface of which is practically free of the above surface defects;
second grade, where a small number of knots with a diameter of no more than 8 mm, as well as brown veins are allowed (usually they are sealed with veneer, but may appear during subsequent processing);
third grade, from which packaging containers or product elements hidden from external view are made.

According to the current GOST 3916.2-96, sheet plywood is produced in the thickness range of 3-30 mm, with overall sheet dimensions from 1220 to 3050 mm. The most common sheet is square in size 1550x1550 mm. Plywood, which is made with bakelite coating, can have a greater thickness - up to 40 mm.

When purchasing from a specialized store, you must pay attention to the humidity stated in the certificate - it should not exceed 8-10%. Otherwise, the material will have to be dried at home, since it is very difficult to process raw materials with high humidity.

The strength class of plywood, and therefore its consumer capabilities, can be determined quite simply in everyday conditions. It is enough to boil a piece of material in water for one hour. If the stress of separation of the layer from the base after such boiling exceeds 1.5 MPa, then the plywood is suitable for making furniture, otherwise it can only be used for small crafts: figurines, patterns, decorative ornaments.

How to make plywood with your own hands

Everyone knows such a material as plywood. This word, even for a person very far from construction or furniture making, evokes a familiar image: sheet material glued together from several thin layers of wood. In general, of course, the image is correct. Because if you intend to buy this same sheet material in a construction supply store, then the price tag will have exactly the same name - plywood.

Plywood production

From the depths of history

As often happens with history, it gets worn out from prolonged use, and now it is no longer possible to discern the details, and only very salient facts are visible.

The name "plywood" comes from the Dutch word "fineer", which means a thin sheet of wood, veneer. But thin wood sheets glued together into a single three or more layered sheet were called arborite.

Thin sheets of wood - veneer - have been known for a very long time. Scientists believe that the most ancient product with a veneered coating is a box-casket found in one of the pharaoh’s tombs. The chest is made of cedar wood, and on the front side it is covered with thin plates of ebony. This was done, most likely, to reduce the cost of the product - Egypt had, to put it mildly, not enough of its own forests, and wood was imported from afar.

Mass production of veneered furniture began in France in the 16th century. This imitation of valuable wood species in furniture production has made it possible to make furniture more accessible to the mass consumer. It is from the carpentry technology of veneering that the slang name for the use of plus phonogram by some performers comes from: “singing to veneer” - imitating for the mass consumer a valuable live performance with a pre-recorded phonogram.

But let’s return to the material glued together from several sheets of plywood - arborite. This technology was invented in 1881 by Ogneslav Stepanovich. Kostovich. Kostovich developed a new material for the manufacture of parts of the Rossiya airship. Not only the skeleton of the airship was made from arborite, but also engine parts, including the transmission shaft, which was thirty meters long.

Kostovich introduced the developed technology into production, founding the Arborit plant near St. Petersburg. The plant produced sheets of arborite and all kinds of products made from it: boxes, wine barrels, suitcases. Construction parts were also produced, even small prefabricated garden houses. A special type of product was arborite pipes, used for the production of yacht spars, ladders, and other things. By the beginning of the First World War, there were about fifty enterprises in Russia producing arborite, although by this time the material had already begun to be called plywood. At that time, Russia was the largest exporter of plywood and plywood products.

Plywood manufacturing technology

As is already clear from the above, the technology for manufacturing plywood at a factory consists of several stages. Let's take a closer look at how plywood is made at the factory.

Primary preparation of logs. Raw materials are selected for the production of plywood. Selection standards are fixed in GOST 9462-88. The logs delivered to the wood processing plant are debarked, cut to the required length - depending on the specified sheet width, then soaked in hot water for some time - hydrothermally treated.
Peeling. The prepared logs are cut into thin sheets of veneer using a peeling machine. The thickness of the veneer plates is 1.5-1.8 mm. The operating principle of a peeling machine is identical to that of a pencil sharpener. Only the blade in the sharpener is fixed at an angle, and in the peeling machine - straight. The blade of the machine is installed tangentially to the growth rings of the log. By the way, our compatriot is also the inventor of the peeling machine. Professor Fisher invented it in 1819.
Slicing, sorting, mending. The resulting veneer is cut into sheets of a certain size. Next, the resulting veneer is sorted. Not only solid sheets of veneer are used. Plates with a width of at least 490 mm are suitable for production.
What is plywood made of: the composition of the material

Non-solid pieces are glued together using edge gluing. The sheets repaired in this way are used to make the inner layers of a plywood sheet.
Drying. The sorted sheets are dried in a special chamber.
Gluing. The finished sheets are glued together, and the veneer plates are positioned so that the wood fibers of the next layer are perpendicular to the wood fibers of the previous one. This method gives the plywood sheet strength. The number of layers depends on the given sheet thickness. For gluing, an adhesive composition is used, the recipe of which is kept secret by each manufacturer. Veneer plates with applied glue are collected in bags, then the cold pressing stage occurs. After this, the sheets are subjected to further hot pressing.
Trimming and marking. The finished sheets are cut to size, sorted and labeled depending on the variety and brand.

Types and brands of plywood

Plywood is made from coniferous and birch wood. Birch plywood is more durable, but also more expensive. Therefore, materials for general consumption, for example, in construction, are most often made from coniferous wood.

There are standards for the production of five grades of plywood. Grade E – elite. It does not allow any defects on the front surfaces. The remaining grades - from I to IV - allow various defects of the sheet surface: the presence of knots, including fallen ones, cracks, wormholes, warping, etc.

This is, in general terms, what the plywood manufacturing process looks like. In the video you can learn more about how plywood is made from birch or other wood.