Plywood - leaf building material consisting of several layers of veneer glued in a special way. Wood fibers of the adjacent layers are located mutually perpendicularly, which gives the plywood mechanical strength. They distinguish the longitudinal faeer, in which the fibers of the outer layers are directed along the long side and transverse. There are other differences in this material, depending on which Plywood finds its application in construction, furniture and other industries.

Main types of plywood

Differences among the modifications of this material consist in appointment, external form, cost, used for the manufacture of wood and in the basic properties (mechanical and physical).

The classification of plywood depending on the processing that determines the properties of the material allows you to allocate the following types.

1. Plywood moisture resistant (marked - FC) - used for interior decoration of various purposes, for the manufacture of furniture, transport packaging. It can also be a floor plywood used as a base for laminate or parquet.
2. Plywood of increased moisture resistance (FSF): Its high characteristics for mechanical strength, moisture resistance and deadlines allow it to be used in all areas of construction, including roofing.
3. Plywood Laminated (FOF) - has an additional coating to protect wood from moisture, due to which it is characterized by the highest indicators of its impacts.
4. Bakelite plywood (FBS) with impregnation with an alcoholoisseum resin) is able to withstand sharp fluctuations in temperature ranging from - 50 to +50 ° C. It is resistant to moisture (including seawater), has a good resistance to open fire. Can be used in the most severe climatic conditions.

Classification of plywood in varieties

Regulatory documents that determine the quality requirements and basic properties of plywood, prescribe the following varietal classification (regardless of the degree of moisture resistance):

• 1 grade admits cracks on the front surface and warning no more than 200 mm long;
• 2 The variety other than the above defect allows for the presence of wood inserts and the performance of glue on the front surface (no more than 2% of the leaf area);
• plywood of the 3rd grade in addition may have worms (up to 10 pieces / m²) with a diameter of up to 6 mm, while limited to the total number of defects - no more than 9;
• The 4th grade of plywood can have fallen bones, wormworms (in unlimited quantities) and irregularities of edges - up to 5 mm.

The trading network includes plywood, the dimensions of the sheets of which are also governed by GOST: 3050 × 1525, 3000 × 1500, 2440 × 1220, 1525 × 1525 mm. At the request of the customer, the plywood sheet can be made with other sizes. Plywood thickness - from 3 to 21 mm.

Plywood characteristics

1. Plywood manufacturers guarantee high mechanical strength of plywood due to a multilayer structure (usually 3-5 layers). Construction properties can be used in construction, in the furniture industry, in the automotive industry.
2. Ease of processing: Phaneur can be cut, drilled, strict the same tools that are used while working with conventional wood. There are technologies that allow you to curb it.
3. This material, resistant to temperature drops, and with appropriate processing to humidity.
4. Good noise insulating and thermal insulation characteristics make Paneur indispensable at the interior decoration of any destination.
5. High aesthetic properties, compulsory with other materials and environmental safety allows you to use Paneur to finish the interior.

Ways to manufacture plywood

There are three ways to manufacture this material.

1. The sawing method: the veneer is obtained from the wood of valuable rock cutting on the strip of a thickness of about 5 mm. The lack of a method is its low efficiency: a large amount of raw materials are consumed.
2. Planing: This allows you to get a veneer with a thickness of 3.5 mm. This method is more profitable.
3. Method based on plywood ridge. In this way, the veneer is obtained with a thickness in the range of 1.2 - 1.9 mm. This is the optimal method for producing plywood.

The process of manufacturing plywood is clearly presented on the video.

Main features and differences in plywood species

This wood sheet material is made of birch woods, pines, spruce, beech, grab, maple, larch.

Wood for plywood

Plywood birch and maple is used to make furniture due to the high aesthetic properties of the facial layers. Pine and spruce plywood is often used in construction: due to the resins contained in the coniferous breed, such a material is additionally protected from moisture. Sheet material from other wood varieties can be used for internal work.

Carpentry shields

Such plywood for the central layer uses wood solid species than for external layers. A variety of carpentry shields is a combined plywood: it has different layers from different material (not only wood is used).

Moisture-resistant plywood

For its manufacture uses coniferous and birch veneer, which glues with each other. This allows you to get a material durable and resistant to moisture at the same time, as well as to reduce the specific weight, which is important for roofing work. The most stable moisture is plywood FBS.

Grinding plywood

Such material is characterized by special surface quality. It is one-sided (marked sh1) and double-sided (sh2). Unlocked plywood is marked accordingly - NSH.

Emissions class plywood

This characteristic means the amount of formaldehyde resins contained in the material. Distinguish two classes:

• E1 is marked with plywood, in which formaldehydes is up to 10 mg per 100 g of dry material;
• E2 is indicated by sheet material with an indicator of formaldehyde content - in the range of 10-30 mg / 100 g.

Bakelite plywood: species and features

This is the most qualitative type of plywood and therefore we will tell you more about it. This sheet material is obtained by fastening a birch veneer using phenol formaldehyde thermosactive resins. Bakelite varnish can also be used, the impregnation of wood that increases its wear resistance and moisture resistance.

Plywood FSF is manufactured using high pressure and temperature: so separate layers of material are so compressed. At the same time, cooling is also carried out under pressure, for which the treatment with water or alcoholoissible solution. Plywood Plywood can be polished and unlighted.

As a result, leaf material with the following characteristics are obtained:

• high mechanical strength and moisture resistance;
• long service life under a wide range of ambient temperatures;
• resistance to the effects of acids, alkalis and sea water;
• fire safety;
• resistance to mold and fungi damage.

This material can be used for:

• facilities decks of vessels;
• flooring and devices of a multi-sized formwork;
• interior decorations;
• manufacture of sports equipment;
• furniture production;
• avia and automotive industry.

There are several types of FBS plywood.

1. FBS1 sheets have less strength than FBS sheets, since it is used for production that the veneer is less qualitative. Plywood of these types is suitable for use in car and shipbuilding for outdoor use.
2. For internal use, plywood types of FBS1-A and FBS-A types are developed: they are suitable for the manufacture of internal elements of the car and finishing the premises. Sheets are attached to walls using rosinel or coumaring mastic.

According to some of its qualities, the Bakelite Plywood exceeds steel, but is easier and therefore finds use in many industries.