home-Ramps-How to make birch plywood. How is plywood made? Features of the production of different types of plywood

How to make birch plywood. How is plywood made? Features of the production of different types of plywood

Plywood is considered the most versatile and easiest to process building material. Despite the not very low cost, its popularity and demand is growing more and more every day. Unlike wood, plywood is lighter, but its advantage over fiberboard and chipboard is obvious - environmental friendliness.

Material characteristics

Wood plywood is made by gluing very thin sheets of wood (veneer) together. This material is easily amenable to various processing, both thermal and mechanical; it can be painted with paint and varnishes of any kind. It is worth noting that plywood harmonizes very well with any other material, which designers successfully use. Veneer, as plywood is otherwise popularly called, has the following characteristics:

  1. It has a layered woody structure.
  2. To produce the material, veneer sheets with a thickness of 2-4 mm are used; as a result, the thickness of the plywood sheet can reach from 4 to 32 mm.
  3. The quality of construction plywood depends on the type of veneer, which can be natural or tinted. Natural veneer is more durable, stronger, environmentally friendly and safer.
  4. It has very good thermal conductivity and environmental friendliness, in which it is superior to chipboard, fiberboard and MDF.
  5. The ratio of performance indicators and production costs of plywood is higher than that of metal or plastic.
  6. It is quite light in weight and easily tolerates temperature changes.

Plywood classification

Depending on the characteristics, plywood of any hardness differs in service life, appearance, types and grades:

  1. By purpose it happens:
  • construction plywood – used in the construction of houses as floors and partitions;
  • industrial plywood – for ship, carriage and automobile construction;
  • packaging plywood – used for packaging large items, furniture, electronic equipment and more;
  • furniture plywood - home and office furniture is made from it;
  • structural plywood - used to create various designs, decorations and exhibitions.
  1. Depending on the number of layers of veneer, plywood can be:
  • three-layer;
  • five-layer;
  • multilayer.

To ensure that the veneer sheets are arranged symmetrically with respect to the central sheet, they are taken in an odd number. In the case when the number of veneers is even, it is necessary to glue the two central sheets perpendicular to the two outer ones, this will increase strength and resistance to deformation. The thicker the plywood sheet, the more expensive it is, accordingly.

  1. There are three types of plywood:
  • moisture-resistant plywood (FC) – moisture resistance is relative, since even in rooms with not very high humidity it can suffer. Actively used in the manufacture of furniture and packaging material;
  • increased moisture resistance (FSF) – due to its good resistance to moisture, it is used not only for interior works, but also external. This type plywood bends well, can easily be processed in other ways - drilling, sanding, planing, sawing, and can be painted and varnished well. Many builders note that working with this material is a great pleasure;
  • increased moisture resistance melamine (FKM) - melamine or bakelite glue is used in production. This type of plywood has a popular name - marine plywood. It is used for shipbuilding, aircraft construction, mechanical engineering, it does not sink in water, has good resistance to most aggressive environments. FKM also differs in that it can withstand more than 100 stains.
  1. Plywood processing can be laminated or conventional.
  2. Depending on the material from which the veneer is made, plywood can be:
  • birch - less in demand due to its high cost;
  • coniferous plywood – made from larch, pine, fir, spruce;
  • plywood from Siberian cedar– used mainly for decoration purposes.
  1. Depending on the number of defects that can be identified by external signs, plywood comes in several classes:
  • E class (elite plywood) - production of plywood without any defects, not counting only minor changes in the structure of the tree itself;
  • I – a defect of no more than 20 mm in length is allowed;
  • II – a defect of no more than 2% of the total area material;
  • III – defects in the form of cracks of no more than 10 per square meter are allowed. m., the area of ​​which can be up to 6 mm;
  • Class IV - very low quality plywood with cracks starting from 40 mm.
  1. Depending on the surface treatment, plywood can be:
  • unpolished (NS);
  • plywood sanded on one side only (Ш1);
  • polished on both sides (Ш2).

A sanded surface is easier to process and has good adhesion to varnishes and paints, which is why this type of plywood is more expensive and is usually used for decoration. Unsanded plywood is often used for hidden work; its price is low compared to sanded plywood.

DIY plywood manufacturing technology

Today, plywood can be purchased at every hardware store. But many people who like to do everything themselves are interested in how to make plywood with their own hands. It turns out that this is possible. To make plywood you will need veneer; you can also make it yourself.

Making veneer at home

Veneer is divided into three types:

  1. Natural – veneer that has the natural color and structure of wood. It is made by sawing, peeling and planing thin layers. It is important to preserve the wood structure. Ecologically pure material, very light.
  2. Colored veneer is the same natural veneer, only painted in different colors.
  3. Fine-line is obtained after the reconstruction of old peeled veneer, which is formed into blocks, and from them, in turn, veneer is made. He can have any color scheme, pattern and dimensions like natural wood.

Depending on the manufacturing method, it happens:

  1. Sawn veneer is the thickest material of all types, obtained through the sawing process.
  2. Sliced ​​veneer is obtained through the process of planing wooden blocks.
  3. Peeled veneer – produced using a veneer peeling mechanism.

Tools for work

To make veneer, and subsequently plywood from it, you will need the following material and tools:

  • wood (birch, pine, spruce), which you can purchase in a specialized store or at a woodworking factory;
  • veneer peeling mechanism for the production of peeled veneer;
  • sawmill for the production of sawn veneer;
  • plane for making sliced ​​veneer;
  • grinder;
  • grinding machine;
  • cold and hot presses;
  • drying chamber;
  • phenol-formaldehyde resin as glue and its components;
  • pencil;
  • varnish or paint.

Veneer manufacturing stages:

  1. The first thing you need to do is select the raw materials (wood). Give preference to birch or pine, in extreme cases, spruce, or use it to combine plywood. Birch is a more durable material, while pine and spruce are lighter.
  2. Prepare the wood for work - peel it from the bark and cut it into 1 m long beams using a sharpening machine.
  3. Lay out the workpiece vertically.
  4. Using a veneer peeling mechanism, peel off veneers of the thickness you require. If you are making sliced ​​veneer, then you need to use a plane, and for sawn veneer, a sawmill is useful.
  5. Cut the veneer into the required pieces.
  6. Dry the veneer in a drying chamber that has the ability to regulate humidity.
  7. Sort and discard the dried veneer.
  8. Then dried veneer good quality can be refined, and the rejected one is recommended to be cut and glued to obtain a sheet of the desired size.

Assembly of plywood

Finished veneer sheets can be collected in bags:

  1. Apply glue to both sides of the veneer and connect the sheets together into bags.
  2. Place the bags under a cold press.
  3. Glue veneer packs into plywood sheets using a hot press. Do not forget that the number of veneer sheets must be odd; they must be connected so that the fibers of the sheets being glued are perpendicular to each other.
  4. Now you can cut the plywood sheets to the size you need.
  5. Sand the plywood using grinding machine so that the surface becomes perfectly smooth.
  6. Finished plywood can be decorated with paint or varnished.

How to bend plywood

In some cases, such as furniture making, you may need bent plywood. It is also possible to bend it at home. The easiest way to do this is with flexible plywood, the thickness of which does not exceed 3-4 mm. Flexible plywood can be purchased at the store. But you can bend plywood of any thickness, but first you need to make an accurate calculation of the plywood - in what specific place you will bend it.

The process consists of the following steps:

  1. Steaming. In production conditions, this is done in special installations, after which they are bent under pressure. At home, you can steam sheets of plywood in the bathtub or in other containers. The thicker the material, the longer it must be kept in water. The minimum time is 15 minutes, the maximum is 5 hours. The water temperature should be 90-100°C. But, as you understand, this is quite difficult to do at home, and not cheap. Steaming can be replaced by soaking in warm and cold water, while the process time increases for cold water 15-30°C 20 times, for warm water 60°C 1.5-2 times. After steaming, the plywood sheets must be bent and secured so that they dry completely in this position. To speed up and facilitate the process, you can only moisten the surface of the plywood and steam the place of the planned bend.
  2. Notching. The method is suitable for plywood with a thickness of 15-24 mm. Using a cutter, you need to make small cuts (no deeper than half the thickness of the sheet) in the places of the planned bend. This is the method used in the construction of boats. The cut blank is bent, another sheet of veneer is glued onto it and secured. The plywood should remain in this position for at least a day.
  3. Gluing. This method helps to create a rounded part. Cut pieces 5 mm larger than the required length. Place the parts on the table in such a way that finished product The veneer directions alternated, this is necessary for greater strength of the plywood. Glue all the parts together and fix them on the workpiece of the shape you need. Once your piece is dry, sand it and remove any excess glue.

Before you start bending plywood, read this useful information:

  1. Transverse fibers are more difficult to bend than longitudinal ones.
  2. The humidity of the rooms in which you plan to store bent plywood sheets should be low - no more than 10%.
  3. Steamed and soaked workpieces bend more easily when warm.
  4. The thicker the plywood, the more difficult it is to bend.
  5. It is easier to bend plywood in which the veneer layers are located parallel to each other.
  6. Do not overexpose the plywood in water, it may delaminate. To find out exact time required for steaming plywood of a specific thickness, you can use an experimental workpiece. Soak it and check the condition every 3-5 minutes.
  7. It is still recommended to bend very complex and voluminous structures in specialized workshops.

Painting plywood

For longer service, plywood must be painted or varnished. This is especially true for material that is used outdoors.

Stages painting work with plywood:

  1. First of all, the plywood is sanded. For this, sandpaper No. 80 is used.
  2. After this, the plywood is coated with an acrylic primer and left for at least 4 hours.
  3. If necessary, the surface is puttied with wood putty.
  4. After the putty has dried, the surface is again rubbed with sandpaper No. 80-100.
  5. Another layer of primer is applied and left for 4 hours.
  6. And the final stage will be the painting of the plywood itself.

Having become familiar with how plywood is made, how it is bent and painted, you can build not only arches and partitions in your apartment or country house, but even make and decorate furniture yourself.

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Plywood - today it is the most popular construction material used in interior decoration. It is made from veneer - glued and pressed wood chips (coniferous and hardwood). Thanks to its unsurpassed qualities, such as low cost and abundance (due to ease of production), lightness and at the same time strength, as well as natural, environmentally friendly purity, it is now so widely used and sold on almost every corner.

Below is given step-by-step instruction to increase its moisture resistance. It will include such simple and elementary methods and recommendations that almost anyone can cope with them, even at home.

What is it for

To prevent moisture from entering or leaving the room. The thing is that varieties of plywood with truly high level water resistance is rare on the market. And in those models that are still present on it, they often use a large number of malicious chemicals to quickly produce waterproof material.

High-quality FSF sheets for industrial use are usually sold in large quantities and are expensive. As a result, it becomes very difficult for an individual buyer to purchase them for personal needs (for example, use as a substrate or finishing a boat). Therefore, the question of how to make plywood moisture resistant interests many.

The easiest way is to avoid contact

It may be easier to protect the plywood from any contact with water than to use additional means to increase its moisture resistance. So, if the walls of a house are finished on the outside with ordinary FC sheets, it will be enough to organize a special canopy (canopy) made of durable materials (for example, steel) to protect the material from snow and rain.

It will also not be superfluous to install a drainage system. The ends still remain the most vulnerable part of the building to the elements, so they can be additionally trimmed with metal or plastic corners and covered with some kind of moisture-resistant sealant.

Buildings that are planned to be finished with plywood sheets ( personal plots, outbuildings) must be placed in well-ventilated areas. Then the moisture that gets on the walls will have time to dry out or erode. Drops simply will not have time to penetrate inside the structure and cause deformation.

Important! Sheets of plywood must be of high quality and not delaminate when you try to pry them off with a spatula or chisel. The varnish coating on the front side should also be of high quality - this will significantly increase their resistance to the water elements. You should not buy material of unknown origin and having obvious deformation defects, scratches, cracks or crumbling.

Sheet processing

Organizing additional barriers to moisture is of course good, but is only suitable for stationary objects. But, for example, how to make the sides of a trailer from moisture-resistant plywood? You can't hide them under a visor.

If the previous option does not solve the problem in any way and the plywood sheets must be waterproof on their own, then they will have to be treated with special means - for example, a paint coating.

How to make plywood moisture-resistant with your own hands using varnish?

To do this you will need to acquire the following materials:

  • natural drying oil;
  • varnish of any marking from the following: 6T, 6C, 4T, 4C, plus any options intended for varnishing floors;
  • fabric for reinforcement - if it is not possible to get fiberglass fabric, you can use regular gauze;
  • turpentine (needed to wet the fabric);
  • paint (preferably oil);
  • corners for finishing the ends of plywood sheets (preferably metal).

Attention! Epoxy and polyester resins It is better not to use for processing. They react with drying oil and interact poorly.

The following tools will be useful for the job:

  • brushes (wide, for varnish and drying oil);
  • powerful iron (for drying plywood);
  • hair dryer or heat gun(instead of an iron, if the dimensions of the sheets being processed are very large);
  • a special cross-cut brush (necessary for high-quality reinforcement);
  • brush, sprayer and roller (required for finishing).

Instructions on how to make plywood moisture resistant at home consist of the following steps

  • Preparation of drying oil.

Before starting work, the drying oil is heated to approximately 50 degrees Celsius.

  • Deep impregnation.

The surface of the plywood begins to be treated with heated drying oil using a brush. Then the surface is heated until the first layer dries (hair dryer/iron/gun)

Important! The drying tool should produce a temperature of 150 to 200 degrees Celsius.

The procedure is repeated 3-4 times.

  • Varnishing.

After final impregnation and drying of the plywood, a layer of varnish is applied to it. This should be done especially carefully at the ends of the sheets.

  • Reinforcement.

After the varnish layer has dried until it reaches a thick consistency, gauze or fiberglass is applied. Several hours must pass between applying the varnish and the fabric. The reinforcement process is important element plywood processing. It helps to increase the durability and strength of the last layer of paint - designed to complete the job. To tightly merge the fabric and the varnish coating, it is first soaked in a vessel with turpentine, and then, when applied, tapped using a cross-cut brush.

  • Second varnishing.

This is done after a few days (the reinforcing material must dry completely.

  • The final.

Final varnishing and painting with oil paint.

If everything is done correctly, then additional maintenance plywood sheets won't be needed for the next couple of years. But sooner or later the paint will start to crumble. Then it will need to be removed with fine sandpaper and the sheet repainted.

Each building material has some kind of classification - division according to a series technical characteristics, the totality of which determines the feasibility 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 in 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 exclusively in decorative purposes, it is used to make furniture and is used in interior decoration premises.

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 mechanical strength sheet, the direction of the fibers of the veneer sheets alternates when laying, and the odd number allows you to maintain the same appearance at 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 required thickness plywood is achieved only by connecting 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 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:

  1. 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.
  2. 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.
  3. By appearance machining: plywood is produced unsanded, as well as sanded on one or both sides.
  4. By number of layers: single-layer plywood practical application does not have, therefore they produce material with a 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 most high quality materials, which is explained by the good physical and mechanical properties of the original veneer, as well as a 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 finished product decreases and performance characteristics remain at the same level. Consequently combined option used for finishing sports equipment, gymnastics and training halls, 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 sheathing internal surfaces cargo transport vans, and also use it for the manufacture of highly resistant formwork for concrete.

The environmental friendliness of plywood is assessed by the amount of residual formaldehyde in the product: an E1 class product can be used for subsequent contact with food products, but class E2 – no.

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 current GOST 3916.2-96 sheet plywood is produced in thickness ranges 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 front side covered with thin slabs 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. New material Kostovich developed 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 arborite sheets and all kinds of products made from it: boxes, wine barrels, suitcases. Construction parts were also produced, even small prefabricated ones 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.

  1. 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, and then soaked for some time in hot water– hydrothermally processed.
  2. Peeling. Prepared logs using peeling machine blossom into thin sheets of veneer. 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.
  3. 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.

  4. Drying. The sorted sheets are dried in a special chamber.
  5. Gluing. The finished sheets are glued together, and the veneer plates are positioned so that the wood fibers of the next layer are perpendicular wood fibers previous one. This method gives the plywood sheet strength. The number of layers depends on the given sheet thickness. Used for gluing adhesive composition, 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.
  6. 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.

Plywood, as you know, is a very common building material. It is used in production construction work (plywood fsf), as well as in the production of furniture (fk plywood). Plywood is also actively used in other areas of production. Plywood is obtained from coniferous trees and birch.

Essentially, plywood is layers of veneer that are glued together. Wood material, which is made from logs by planing is called sliced ​​veneer, and that made by peeling is, accordingly, peeled veneer. Subsequently, it is glued and pressed. In addition, there are varieties in which veneer is combined with other types of materials. For example, a moisture-resistant type of veneer is impregnated with organic polymers, and a laminated type is covered with a phenol film. Based on the quality of processing of plywood, it can be divided into sanded and non-sanded types. The most popular formwork plywood is used when working with concrete.

When gluing layers of plywood, natural or synthetic thermoactive adhesives are used. They are the ones who prevent the fabric from delaminating. Moreover, even serious temperature changes or sudden changes in humidity levels do not interfere with this.

Coniferous plywood, main advantages

Coniferous moisture-resistant plywood is usually made from spruce. It provides high strength output and at the same time the canvas weighs very little. It is worth adding to this that such plywood is resistant to rotting and practically does not deform. Plywood layers impregnated with phenol-formaldehyde glue do not allow fungi and putrefactive bacteria to multiply.

Coniferous plywood is not inferior in strength edged board, despite being 25% lighter than birch plywood. When used, the load on the existing rafters in the roof is reduced. At the same time, functional qualities are not lost. Moisture-resistant plywood practically does not warp in comparison with other lumber. In extreme cases, warping can be easily corrected by gluing, tensioning and strengthening with nails.

Plywood stretches without cracking. The fact that it is manufactured makes it easier to work with plywood large sizes. The need for bonding, as is the case with other lumber, is completely eliminated. Plywood can be easily bent, making it easy to transport.

In addition to spruce and birch, plywood is also made from pine, fir and cedar. In some cases, you can even find plywood based on oak, beech, linden, aspen, maple, larch, alder, ash and elm. If we are talking about elite plywood, then it is made from walnut. Moisture-resistant plywood varies in the number of sheets. It can be three-layer, five-layer and multi-layer.

Coniferous plywood is always very smooth, resistant to impact environment, which means it is very durable. However, it is worth touching on the dimensions of moisture-resistant plywood. So, the overall size is 1.22 x 2.44 m (w x d). At the same time, the thickness of plywood can be very thin - 9 millimeters, as well as 12 millimeters, 18 millimeters and even 22 millimeters.

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.

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.

  1. 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.
  2. 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.
  3. 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. 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.
  4. Drying. The sorted sheets are dried in a special chamber.
  5. 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.
  6. 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.

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