Characteristics of plywood that are important when choosing: grade, types, classes

Today we will talk about what kind of plywood is used in furniture production. We'll tell you how to choose plywood sheets for making various types of furniture and structures.

Plywood is more expensive than MDF and chipboard, often used in the manufacture of cabinet furniture. But this drawback is covered by two more important advantages: increased strength and the ability to produce bent elements. Therefore, plywood is just as in demand in furniture production as MDF and chipboard panels. We will tell you which plywood is suitable for making various pieces of furniture and its individual elements.

Plywood as a universal material

Plywood is a multilayer building material that is made by gluing together several layers of veneer. Veneer is very thin layers of wood, which are presented in a plywood sheet in odd quantities (3 or more). In order to increase the strength of the material, the veneer is applied in such a way that the wood fibers run strictly perpendicular to the fibers of the previous sheet.

Application of plywood sheets

Plywood is used in the following industries:

1. In the aviation industry.
2. In shipbuilding, including making boats with your own hands.
3. In furniture production.
4. In electrical engineering for the manufacture of various insulating products.

A few words on material classification

Features of furniture plywood

Advice! For the production of kitchen furniture, only plywood with a high level of moisture resistance should be used. The best option is FSF sheets. Otherwise, such pieces of furniture will quickly lose their attractive appearance under the influence of moisture and frequent temperature changes.

Advantages and disadvantages of plywood sheets compared to wood

Materials such as furniture board or plywood are successfully used in furniture production, and today, much more often than natural wood. As mentioned above, the main reason for this is the low price of plywood sheets.

However, in practice this material has a significant number of advantages.

Let's look at some of them:

1. It consists of wood, only from thin layers (about 1 mm), and its price is an order of magnitude cheaper.
2. Even large plywood sheets are shaped stable. This is achieved due to a special production technology - crossing veneer fibers.
3. True freedom of choice regarding sizes.
4. High lateral strength when compared with a wooden panel of the same thickness.

Unfortunately, this material has in addition to its advantages.

It also has some disadvantages:

1. The mass of a plywood sheet will be greater than that of a wooden sheet of similar thickness.
2. The ends have stripes, which affects the aesthetic perception of the product, since many have a negative attitude towards plywood as a material.

Lining the ends of plywood.

Advice! If you don't want the veneer layers to be visible on the ends, they can be sealed or coated with several layers of dark varnish.

1. This material gives you less freedom in surface treatment, since the front layers are about 1 mm thick, so they can be “removed” with a tool if you are careless.
2. Some manufacturers save on adhesives by using adhesives that are harmful to human health. Thus, purchasing plywood from an irresponsible manufacturer can have unpleasant consequences, which cannot be the case with the purchase of natural wood, even of the lowest quality.

Other selection factors

The choice of plywood sheets for furniture manufacturing is influenced by the following factors:

• Variety Elite is the best choice. But it cannot be found on the open market, since it is sent in bulk to furniture factories on special orders. But grades 1 and 2 are also good options. To save money, you can choose 1/2 or 1/3 grades. The front side will be the one whose outer layer of veneer is grade 1. The reverse side will be wrong side.
• Thickness. For cabinet furniture, the optimal thickness is 15-18 mm. For podiums – at least 20 mm. For non-load-bearing partitions, thinner sheets can be used - about 8-10 mm. For sealing the back wall of furniture and constructing the bottom of drawers, plywood 3 mm thick is suitable. For this purpose, you can also purchase cheaper fiberboard material.
• Surface treatment method. Plywood must be sanded on both sides. To save money, you can buy unsanded sheets, but in this case you will have to sand them yourself.

When choosing plywood for furniture, also pay attention to its format. It should be enough to cut workpieces of specified sizes. Please note that the standard size of FC sheets is 1525x1525 mm. To prevent the formation of seams in unnecessary places when making large-sized furniture, it is better to purchase laminated plywood, which is produced in the 2500x1250 mm format .

Features of making furniture from plywood

Knowing about the flexibility of plywood in work, many home craftsmen have probably thought about making their own furniture. And in reality there is nothing particularly complicated here - you just need to follow simple recommendations in your work.

The instructions for working with plywood provide several tips:

1. This rule applies to working with sheets of different thicknesses:
   The thickness of which is no more than 1.5 mm. In this case, the material should be cut exclusively with a knife.

Cutting a sheet using a stationery knife.

• If the thickness is more than one and a half millimeters, but less than six, then you should use a jigsaw.
• If the sheet is more than 6 mm thick, it will have to be cut with a circular saw.

1. Never cut plywood boards across the grain, as this will cause the material to crack. To prevent this, loosening cuts should be made. They are made using a knife, applied parallel to the sawing line.
2. Before joining sheets with screws or nails, it is necessary to pre-drill holes, otherwise cracks will form in the material.

Advice! If you are connecting building materials made of soft wood with screws, then you should place small washers under their heads.

1. To bend the panel, you must first moisten it with water and then fix it. The sheet should be kept in this position for about 12 hours.

Furniture plywood

Currently, there are many building materials that are used for repair and finishing work. One such material that is very popular is furniture plywood . It is a durable product with a long service life. In terms of cost, plywood is much cheaper than natural wood. This material is used to make furniture.

First, you should understand what a material such as furniture plywood is.

What is furniture plywood?

Plywood is a building material made by gluing together several layers of veneer. Veneer is a thin-layered wood. To make a plywood board, an odd number of layers of veneer are used, ranging from 3 or more. To increase the strength of the product, the veneer layer is glued so that each subsequent layer is located perpendicular to the previous one.

To create furniture, plywood sheets with a thickness of 3-30 mm are used. As a rule, 3-layer plywood is used to make cabinet walls and furniture bottoms and has low strength. The five-layer material is characterized by high strength and is used in furniture production for the manufacture of tabletops.

To make the front surfaces of high-quality furniture, expensive decorative plywood is purchased.

Since plywood furniture should not only be durable and strong, but also attractive in appearance, its production is carried out in special factories, where special attention is paid to the choice of glue and details of the products.

Dimensions

Manufacturers make and supply to retail outlets a wide range of plywood sheets for furniture, which have various technical characteristics. Experts, first of all, recommend paying attention to the thickness of the material, which has a fairly wide range: from 3 mm to 30 mm. The thickness of the product directly depends on the number of compressed layers, which affect the strength of the material. Beginning craftsmen should remember the following dependence of the nominal thickness on the layer level:

• 3–4 mm – 3;
• 6 mm – 5;
• 9 mm – 7;
• 12 mm – 9;
• 15 mm – 11;
• 18 mm – 13;
• 21 mm – 15;
• 24 mm – 17;
• 27 mm – 19;
• 30 mm – 21.

The thicker the plywood, the greater its weight, but the strength also increases several times.

The number of layers may vary depending on the type of wood used.

Pros and cons of furniture plywood

Today, plywood is more popular in furniture production than its natural counterpart - wood. This is due to the fact that plywood sheets are much cheaper than natural wood. In addition, this building material has a number of advantages:

First of all, it should be noted that plywood is made from natural material, only in this case thin layers of wood are used. With all this, the cost of a sheet of plywood is much lower.

Despite the size of the plywood board, we can talk about the stability of its shape, which is achieved using a special technological process, namely cross-layering of veneer layers.

Another advantage is the wide choice of material sizes.

High strength of plywood sheet compared to wood of the same thickness.

In addition to the advantages, this building material also has some disadvantages:

These include the greater mass of one sheet compared to a wooden slab of the same thickness.

There are stripes at the ends of the product, which subsequently spoil the appearance of the surface being treated. Because of this, the frequency of its use is somewhat reduced.

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The choice of material for processing plywood sheets is limited. Since, if necessary, remove the old coating and apply a new one, you can also remove the top layer of the material itself. And this will affect its quality and durability.

Treatment

Based on the type of processing, plywood is divided into sanded and unsanded:

NSh Unsanded Ш1 Sanded on one side. Ш2 Polished on both sides.

Unsanded plywood is produced in only 4 grades. It is also called construction grade or construction plywood. And it is most often used in construction, when it is necessary to carry out rough work at the lowest possible cost - rough cladding of facades or interior partitions for subsequent finishing, in the production of durable packaging, for the manufacture of frames for inexpensive upholstered furniture, as a cushioning material for laying floors etc. Sanded plywood is used for more delicate purposes - the production of souvenirs, furniture facades, interior decoration, etc.

Sheets of unsanded plywood may have large gaps in thickness. The thickness of sanded plywood sheets varies much less; it is not very precise, but is calibrated in production. The type of processing does not affect the quality and technology of plywood milling. Prices for milling sanded and unsanded plywood are the same.

The most important parameter when choosing a material for milling!

The grade indicates the number of defects on the visible veneer sheets. It is usually indicated by a pair of numbers, such as 2/2 or 2/4.

It is very interesting that manufacturers sort the produced plywood differently. Large factories (Sveza, Demidovo, Segezha) classify quite decent 2nd grade material with small unprincipled nuances as 3rd grade. Less well-known and small manufacturers can pack 3rd or even 4th grade material into a pack of 2 grades. You can only notice this in the workshop after unpacking the pack.

There are five grades of plywood.

According to
GOST 3916.1-96,
plywood grades are designated “E”, “I”, “II”, “III”, “IV”. For convenience, Roman numerals are replaced with Arabic 1, 2, 3 and 4, respectively.

Along with this marking, the old classification system established by GOST 3916.1-89 is actively used.

In accordance with it, plywood is also divided into five grades, but they are designated differently - “A”, “AB”, “B”, “BB”, “C”.

Grade E (A) Elite class plywood, visible flaws and processing defects are not allowed. Rare and most expensive variety. Grade 1 (I/AB) Allows the presence of up to two defects (inserts) per 1 m 2. Quite a rare and expensive variety. Grade 2 (II/B) Allows up to 8 defects (inserts) per 1 m 2, changes in color and texture may occur. The most popular grade of plywood for the production of furniture, souvenirs and other similar products. Grade 3 (III/BB) The number of defects increases to 10 per 1 m2, knots appear, and there is a change in color and texture. A good option for the manufacture of internal frames for reception desks, furniture, interior partitions, etc. Grade 4 (IV/C) Defects of any kind are allowed. Material for rough work.

For the production of low-grade plywood (grade 3, especially 4), lower quality wood and adhesive composition are used. Parts made from such plywood after milling can literally delaminate and fall apart; during the milling process, chips may appear on the edges of parts, chips may fly off or a knot may fall out. You need to choose low-grade plywood only when the appearance of the finished product is not of decisive importance. Prices for milling high-grade and low-grade plywood are the same.

Furniture production using plywood

Furniture plywood has good flexibility. It is this feature of this material that often pushes craftsmen to make some kind of furniture with their own hands. In fact, there is nothing difficult about this if you follow certain instructions.

Regarding the thickness of the material, it should be noted that for different thicknesses of sheets, different cutting methods are used. So, if the thickness of the plywood is no more than 1.5 mm, then you only need to cut it with a knife, but if it is more than 1.5 mm, up to 6 mm, then you will need a jigsaw for the job. If the product thickness is over 6 mm, you will need to use a circular saw to cut plywood.

It is not recommended to cut a sheet of plywood across the grain of the veneer, otherwise the material will begin to crack. To avoid this, make small cuts with a knife parallel to the sawing line.

Before fastening the sheets with screws or nails, you must first make holes in the slab so that the sheet does not crack.

In places where furniture plywood is bent, it must be moistened with water and only then mounted.

There is a special sequence for gluing plywood sheets. The surface on which the plywood board is supposed to be glued should be cleaned with sandpaper. The glue must be applied in a thin layer. After this, the material is compressed until it hardens completely.

Furniture plywood is considered a good material for making furniture. Even though plywood products are not as good in quality, they are often superior to natural wood due to their technical performance. With the right choice of material, you can get good furniture at a low cost, which will last a long time and have a pleasant appearance.

Characteristics of plywood

Technical characteristics of various brands of plywood.

Source: mosfanera.ru

Plywood for furniture. Types and grades of plywood. Materials Science.

[td] Wooden kitchen is a very vague concept. The materials for it include both expensive solid wood glued together from natural wood beams and budget slabs pressed from sawdust and various binding resins (including formaldehyde). But if you’re going to make a kitchen with your own hands, you should choose the golden mean – plywood. It is quite affordable, easy to process and more environmentally friendly compared to the same chipboard What does a furniture maker need to know about plywood? Plywood is a kind of “pie” made from thin sections (from 0.1 to 1.18 mm) of solid wood - veneer. There is always an odd number of layers, and they are laid perpendicular to the direction of the wood fibers. The sections are joined using high-pressure adhesive, resulting in a durable, wear-resistant material. Composition - for the manufacture of plywood, veneer is used from coniferous (pine, spruce, fir, larch, cedar) or deciduous (most often birch, linden, oak) tree species. Based on the number of layers, it is divided into three-, five- and multi-layer.

Types of plywood.

There are several main types of plywood, depending on the material used.

Apart from the finishing methods used to process finished material, it is the base from which this or that type of plywood is produced that determines its performance characteristics in the future. Each type of wood has its own individual characteristics and properties, which means that a product made from trees of a particular species will be endowed with such properties to a certain extent. Let's look at the characteristics of the main types of plywood:

Birch plywood . Birch plywood, due to the properties of the wood from which it is made, is distinguished by its highest strength. Of course, this is precisely the quality that determines to the highest degree the demand for this material. The most common type of birch plywood used for interior decoration and furniture making is FC plywood , which is also characterized by an average level of moisture resistance and environmental friendliness. Among other things, this plywood has a pleasant color scheme and pleasant texture, and is easy to process. birch plywood is best suited for outdoor work, since it is a more moisture-resistant material and is actively used in construction, formwork, mechanical engineering, etc.

Coniferous plywood . The main characteristic of plywood, which is made from pine wood, is high strength with relatively low weight, which makes it the best option for use in house construction. This plywood also looks great. Work such as creating bases for floors, cladding walls, erecting partitions, covering roofs - in low-rise housing construction is often carried out using coniferous plywood. In addition, coniferous plywood best meets the needs of the furniture industry, packaging manufacturers, interior designers, etc.

Combined plywood (birch/coniferous). Combined and birch plywood are similar in appearance, however, due to the fact that the birch and coniferous veneer in combined plywood are glued together in layers that alternate, the cost of this material is somewhat lower. If we talk about strength, then combined plywood is not as strong as birch plywood, however, it is stronger than coniferous. This set of characteristics has made this wood-based panel material in demand for performing the same work as birch plywood, and interior decoration is also one of the main areas for using combined plywood.

Unidirectional plywood . This type of plywood is fundamentally different from other varieties in that almost all veneer layers in it are directed in the same direction - which is why unidirectional plywood is a very elastic wood-based panel material. The specificity of such plywood has made it in demand in the manufacture of upholstered furniture, and, for example, hockey sticks are made exclusively from plywood of this type.

Laminated plywood . The lamination effect is achieved by covering the plywood with a special film (based on phenol-formaldehyde resins). This coating significantly increases the wear resistance and moisture resistance of ordinary plywood, having a key effect on density and strength. The layers of wood veneer in such plywood are also glued together with glue based on phenol-formaldehyde resins. Such plywood is used for purposes in which wear resistance plays a key role - formwork, floors, various types of cladding, up to the construction of bridges (large format plywood is used).

Bakelite plywood . This type of plywood has its own special characteristics - it is indispensable for use in aggressive environmental conditions - sea salt water or, for example, a hot tropical climate does not subject it to destruction. This plywood is made from birch veneer using bakelite varnish as an impregnation.

Class “E” plywood is considered the best - during its production the presence of knots, cracks, chips and wormholes is not allowed. It is used in finishing work and in the manufacture of furniture, since the smooth surface is ideal for any finishing treatment and looks beautiful when opened with varnish, paint, wax or oil impregnation. The remaining grades (from 1 to 4) allow an increasing number of defects, and if with grades 1 and 2 you can still try to save money, then with grades 3-4 I should experiment - the large amount of waste and low quality of products are not worth it.

Description

Furniture plywood is a universal building material that is made from natural wood raw materials and has several layers.

Experts recommend paying attention to the advantages of furniture plywood:

• environmental Safety;
• low price range;
• absence of dimensional fluctuations at unstable humidity;
• ease of use, maintenance and restoration;
• wide range of sizes;
• light weight;
• flexibility;
• high level of strength;
• Possibility of making furniture yourself.

We should not forget about the disadvantages:

• the presence of unaesthetic layered layers;
• inability to use certain finishing materials;
• complexity of repair work;
• low level of resistance to constant mechanical loads.

When purchasing this building material, you must pay attention to the adhesives used.

To reduce the cost of goods, many manufacturers use low-quality solutions with harmful substances that make plywood toxic and hazardous to health.

The basic raw material for plywood is peeled veneer, which is produced using the following technology:

• steaming wood;
• processing (peeling) of material on a special machine;
• straightening and drying the workpiece;
• final pressing and gluing of veneer sheets.

Thanks to the use of this technology, the finished multilayer sheets have a high level of strength and low weight. Manufacturers use the following tree species as base material: coniferous, deciduous.

• Conifers are a sought-after wood that is used both for making furniture and for construction. Advantages: resistance to moisture, saturation with natural resins, the ability to avoid the use of impregnation, high antiseptic properties. The disadvantage is the low level of strength, the presence of resin secretions when heated.

• Deciduous is a wood that is rarely found on sale. The most common is birch veneer, but you can purchase items made from alder, poplar, maple or aspen. Advantages: high level of strength, resistance to mechanical damage. Disadvantages: high price range, lack of natural resin protection, the need for mandatory treatment with protective compounds, low resistance to moisture, complexity of manufacturing and impregnation.

Manufacturers often combine two types of wood. Softwood sheets are usually placed inside the veneer, and hardwood veneer is installed on the outside.

On sale you can see different plywood, which differs in the following parameters:

• variety;
• view;
• base material;
• type of impregnation.

Features of plywood depending on the grade:

• the highest - high-quality material that is completely free of external defects;
• the first is plywood, which may have small cracks and darkening on the front side of no more than 20 mm in size;
• the second - sheets in which the presence of leakage of the adhesive composition, as well as the presence of foreign inclusions, is permissible; the permissible amount of defects should not exceed 2 percent of the total area, and the length of one crack should not be more than 25 cm;
• the third is plywood, on the surface of which there may be black dots with a diameter of up to 5 mm;
• fourth - a material of very low quality, on the surface of which you can see wormholes, depressions and bumps, and the edge of the sheet may have chips and deformed areas; this material is very rarely used in the manufacture of furniture.

Depending on the type, plywood comes in the following categories:

• FOF is a moisture-resistant material, the surface of which is covered with a decorative colored polyvinyl chloride film;
• FSF is a high-quality material that has a non-laminated surface and a high level of resistance to moisture, the advantage is a wide range of applications, the disadvantage is the presence of formaldehyde in adhesives;
• FC – birch veneer, the sheets of which are glued together using urea and formaldehyde compounds;
• FBS is a high-quality plywood that is treated with Bakelite-based varnish and has an improved physical and chemical composition; its advantages are a high level of resistance to moisture and temperature fluctuations.

Also, plywood can be either laminated or bent. Laminated material has an attractive appearance and is used to make any type of furniture.

Advantages - high level of strength and resistance to moisture, high aesthetic values, affordable price range, ease of maintenance and restoration.

Bent wood is an interesting material from which unusual furniture with an original structure is made. Advantages: creation of any shape, possibility of combination with different building materials, permissibility of use both indoors and outdoors.

Depending on the level of processing, plywood can be of the following types:

• unpolished;
• one-sided polished;
• double-sided polished.

Particular attention should be paid to lightweight white plywood, which is made from trees growing in the tropics.

Advantages - low specific gravity, the presence of a smooth fibrous surface, the absence of voids, ease of processing.

Types of plywood.

Sorting - changing the grade depends on the defects of the wood, which has 28 points.

Marking - depending on the adhesive composition, plywood is distinguished:

• FC (urea glue),
• FKM (melamine resins),
• FBA (albumin casein glue),
• FSF (phenoformaldehyde),
• FB (bakelite varnish),
• BS (alcohol-soluble bakelite glue).

Of course, not a single composition reaches absolute environmental friendliness (after all, it is a product of the chemical industry), but FBA plywood, the glue for which is made on the basis of protein, is considered the safest for health.

Plywood based on formaldehyde glue has emission class indicators for harmful substances (like chipboard). For residential use, it is recommended to purchase materials marked E0 or E1.

Surface treatment - unsanded plywood is designated “NSh”, with one sanded side - “Sh1”, with both sides - “Sh2”.

Dimensions - standard plywood sheets can be either square or rectangular. The minimum length is about 1.5 m, the maximum is a little more than 3 m. And the thickness varies from 3 to 30 mm.

Source: www.makuha.ru

Degree of water resistance of the adhesive joint

In addition to the type of veneer, plywood differs from each other in the characteristics of the adhesive connection. Based on this indicator, the following grades of material are distinguished.

FSF is a material of increased water resistance for external and internal use. The adhesive joint of plywood is created using phenol-formaldehyde resins. Thanks to them, the material is characterized by increased water resistance, mechanical strength, dimensional stability, and wear resistance. The flip side of the advantages of FSF brand plywood is the high percentage of toxic phenolic compounds. In addition, the resin used for gluing veneer is flammable, and the combustion products of the resins themselves pose a real threat to human health.

FC – waterproof plywood for internal use based on urea glue. This type of material differs from the FSF brand in lower water resistance, but at the same time it is completely environmentally friendly and odorless. FK brand material is chosen for interior decoration of residential and technical premises, creating furniture, etc. The environmental safety of plywood and low flammability make it optimal for burning.

FB is a highly water-resistant plywood that uses bakelite varnish. In addition to resistance to critical humidity levels, this material demonstrates unsurpassed mechanical strength, wear resistance and is adapted to large temperature changes. FB plywood retains all its operational advantages even with prolonged contact with water.