The difference between plywood fk and fsf. Plywood FK and FSF: what is the difference, what is Plywood FSF or FK better

11.03.2020

When carrying out certain construction and repair work, it is fundamentally important to know what is the difference between FK and FSF plywood. Outwardly, at a glance, it is quite difficult to distinguish one species from another; only an appropriate specialist can handle this. The visual difference can be found in the color of the interlayers: in FK they are lighter, have a shade of veneer from which the sheet itself is made. PSF is layered with darker glue, which has a slightly reddish tint.

However, the average user will be able to notice such subtleties only if you put the samples next to each other. Meanwhile, when buying plywood for repair and construction purposes, you need to know exactly what to take, since both the physico-chemical characteristics and the purpose of these types are quite different. You should not make a mistake even if you value health (for yourself and your family) and want to get reliable and beautiful repair results that do not require an urgent rework soon.

What is the difference between FK and FSF plywood and what is each of them intended for? tasks and some specifications compared materials are different. What and how - we will try to tell in detail in this article. We hope that our advice and recommendations will help you to approach responsibly the choice of interior and exterior finishes.

What is hidden behind the letters "FK" and "FSF"?

Any plywood sheet is a minimum of 3 (more often - even more) layers of wood veneer, each of which is perpendicular to the previous one. Due to this arrangement, significant strength and ability to maintain a given shape is achieved. Pine and birch are most often used for veneer, although plywood can also be made from other types of wood, mainly hardwood. The most common types of plywood are:

birch - all layers of veneer are made from the corresponding tree;
coniferous: only pine went to the veneer;
combined - the middle layer is made of pine veneer, the outer ones are made of birch.

The very name of plywood already contains an indication of the type of glue that went to connect the individual layers. So, "FC" is deciphered as follows:

"F" - plywood;
"K" - urea-formaldehyde glue.

Plywood FK is produced more often from birch or alder - deciduous trees, conifers usually do not participate in it.

In the abbreviation "FSF", the first letter means the same plywood, and resin formaldehyde glue is hidden behind the SF.

Differences between FC and FSF

The whole difference is determined by the glue that is part of the sheets.

Environmental friendliness

In this regard, plywood of the FK brand is cleaner: during its operation, phenols simply cannot physically be released - they have nowhere to come from. PSF contains phenols in an amount of 8 mg / 100 g - an indicator not too high, but considered unsafe in residential areas. In order to maintain fairness, it must be said that the FSF emission class is assigned to E1, that is, there is no direct ban on its use in dwellings. But where there is an opportunity to avoid it, it is still worth using it and not using this material.

Water resistance. In this regard, formaldehyde glue provides higher performance. Strong wetting of the PSF causes the plywood to swell, but after drying, if it did not stay in the wet state for long, the PSF returns to its original dimensions, and this practically does not affect its appearance and properties. FC, on the other hand, from moisture will certainly either begin to exfoliate or curl. The reverse recovery mission is impossible, the loss appearance and characteristics is irreversible.

Application area

It is determined by the above features of building materials. Experts recommend using FC only in interior work due to low moisture resistance, including children's rooms - and also due to the safety of this plywood. PSF, due to the harmfulness of the components and good water resistance, is more often recommended for outdoor use, in particular for the manufacture of frame structures.

Strength

It is larger for the FSF, so such sheets are used for the manufacture of supporting structures. For example, this plywood can be used for subfloor equipment, provided that a continuous finishing coating is laid on top. If plywood will act as the top layer, for example, varnishing of sheets is planned, then the FK brand is taken.

The decorativeness of both types of plywood is approximately the same and depends on the class - the higher it is, the less knots and defects on the sheet. But due to the shade imparted by the PSF glue and insufficient environmental friendliness, FC is used in finishing work.
The combustibility of both types of plywood is the same, with the exception of FSF brands-TV: it is known as "hard to combust" and is used in car building.

Worthy alternative

If for some purpose you need plywood that combines the advantages of both described types and is devoid of their inherent disadvantages, pay attention to sheets marked FB. The third letter in the abbreviation indicates the solvent base for the adhesive resin: B - water-soluble, C - alcohol-soluble. The high characteristics of FB plywood are due to the peculiarities of its production: before pressing with glue, the veneer is impregnated with bakelite varnish (this is what is meant by the letter B). This technology provides high physical and technical characteristics:

FB plywood has the highest water resistance: it can be used even in sea water, due to which it is widely used in shipbuilding;
the material is refractory, does not ignite, and when exposed to temperatures of the order of 350 Celsius, it chars, but does not burn;
FB is non-toxic, can be used even in children's institutions;
plywood does not deform at temperature drops in the range from minus to plus 50;
it is not affected by many aggressive media that are harmful to wood: gasoline, weak acids, kerosene, oils, alkalis;
FB weighs more than wood, but it doubles in strength;
without the slightest changes, FB plywood serves in difficult conditions for up to 10 years.

An interesting fact: it was from it that kamikaze planes were constructed, from which the idiomatic expression "plywood over Paris" appeared. So the material can be considered unique and devoid of flaws. Except for one thing: FB costs 2-3 times more than FK and, moreover, FSF, and therefore it is usually used in industry and large-scale construction. And ordinary people, having found out what is the difference between FK and FSF plywood, make a choice between these two brands: for repair purposes, their qualities are usually more than enough.

A plywood sheet is a material made up of 3 or more densely glued layers of wood veneer. The placement of the fibers in it is strictly perpendicular, which gives it greater reliability in different directions and a stable shape. Plywood is often used as a material for construction and for the production of furniture.

Properties

PK (laminated plywood) is a relatively inexpensive raw material and, as a result, is in great demand. In addition, silicate glue is used in its manufacture, which is minimally harmful to human health. It is produced from birch or alder, probably a combination of these tree species. When hit by FC a large number moisture, then in the process of drying it has the ability to exfoliate and curl. Such plates can be up to 40 millimeters thick, and are divided into types due to the presence of knots on the surface.

For gluing, glue based on urea-formaldehyde resin is used. It is distinguished by low moisture resistance and therefore is used as a base for laminate or parquet in rooms with relatively low humidity, for the production of furniture and wall decoration. This kind of raw material is reliable and durable, which is especially provided for when purchasing furniture.

Description and application

Plywood of this type is used for the production of packaging and containers, and besides this, in the construction and manufacture of furniture.

The basis for this type of material is wood veneer, peeled in a special way, birch or pine veneer. As a rule, the manufactured sheet is glued together in several layers of similar veneer. Therefore, the thickness of sheet plywood also fluctuates. The adhesive is based on phenol-formaldehyde resin. Although a maximum of two types of wood are used for the purpose of production, sheets can have three main subtypes. These are constructions of only pine or birch veneer or a combined sheet, inside of which there is pine veneer, and birch is covered on top.

Plywood FSF

It has quite indicative qualities in practical terms. This is reliability against impacts and various mechanical defects, resistance to absolutely all types of moisture, ease of processing, which is very important when you intend to carry out with my own hands repair and construction work.

Such sheets are used most of all in the production of furniture products, various partitions between rooms. They are also often used to make large marketing billboards. Whereas for roof supports and frames, they are one of the most durable and cheap materials.

Thus, the key properties of 2 types of plywood have been considered. Now is the time to summarize and characterize the key differences between these plywoods. This will help you make right choice certain type material for work. First of all, the main differences between plywood are their moisture resistance. But we will carry out the description in more detail according to the main aspects.

Main criteria

Security

Here, the greatest interest should be given to the adhesive for plywood layers. From the foregoing, a certain conclusion suggests itself - FSF plywood is the most harmful to human health, since it includes phenol-formaldehyde, which is quite dangerous in the composition of the adhesive. And plywood-glued sheets have a significantly lower harmfulness. Thus, it is more correct to use plywood-glued sheet for the purpose of interior decoration and in residential premises for household furniture. Whereas FSF cannot be used for these purposes. This type will look better in outdoor structures that are constantly in the fresh air.

Reliability

The first position here is occupied by the materials of the FSF. Actually, therefore this plywood It is used for rigid resistant structures, which in the future are expected to produce a considerable load. It is impossible to rely on glued plywood in this situation, so it is pointless to produce serious furniture and supporting structures from them.

moisture resistance

PSF in this situation has a higher significance, so it can be confidently applied in all directions. The difference is that plywood sheets have little moisture resistance, all this is manifested in the fact that this type of raw material is categorically not recommended for the street and damp rooms.

decorative

According to this criterion, these two types of material are quite good in terms of their performance. Everything will depend on the quality of the product from a particular manufacturer. The better this level of the sheet, the smaller the number of different scratches and knots on them. From the experience of builders, it can be determined that most often both materials are chosen as the basis for decoration without any preferences.

So, the key properties of the canvases are fully considered. It was worth noting the fact that these two materials have their pros and cons, they must be taken into account when designing different works, otherwise the choice is up to the consumer.

During construction and repair work, it is necessary to know how FK plywood differs from the one that is commonly called FSF. If we talk specifically about the external component of such building materials, then it should be noted that it is almost impossible to distinguish them from each other, taking into account such a parameter, at least for the average consumer!

Some visual differences can only be detected by you in the color of the interlayers, as in the case of FC, they are lighter and have a certain shade of veneer. As for the FSF, it layered with darker glue, the presence of which causes the reddish tint observed in this material. Do their main differences come down to these features alone? Of course not. That is why, if you are interested in such an aspect, then we are ready to note for you the parameters that distinguish them from each other.

Environmental friendliness

If we talk specifically about this parameter, then it should be noted that in this regard, it is plywood of the FK brand that is much cleaner, during the operation of which the possibility of phenol emission is excluded. As for PSF, these phenols are contained in them in an amount 10 mg/100 g, about. In principle, this figure is not too high. However, it is considered unsafe if we are talking about living quarters, and in the event that you consider it necessary to use them in such a situation, then you should have provided for this aspect as well.

Plywood FC

Water resistance

According to the practice of using PSF, it should be noted that their strong wetting can cause plywood to swell. Certainly, big problem it is not necessary to do this, since after drying (if it was relatively small in the wet state, then in this case, the PSF can be returned to its original dimensions, without losing the properties of such a material, and also without any changes in its appearance) . As for the FC, it, under the influence of moisture, will immediately begin to delaminate or twist, and the subsequent restoration of such plywood will be practically impossible, since its appearance and characteristics will be lost.

Plywood FSF

Strength

In this regard, FSV, again, is better than its closest analogue - that is, FC. This parameter determined the fact that such sheets can be used for the manufacture of various supporting structures. Such plywood can always be used in relation to subfloor equipment. In this case, it would be necessary to take into account the mandatory condition, the meaning of which boils down to the fact that a finishing coating should be observed from above, which should be continuous. Well, in the event that varnishing of sheets is planned, and therefore, plywood will have to act as the top layer, then in this case, it is best to give your own preference to the FK brand.

Application area

FK plywood differs from FSV also in the area of its own application. This aspect should be determined taking into account the above-mentioned features of both of these building materials. If we are talking about FK plywood, then in this case, its use is especially important during interior work, due to its low moisture resistance. Among the premises on the territory of which it is best to use FC plywood, one could include children's rooms, for example.

The purchase of FSF plywood, due to the presence of a whole list of harmful components, is recommended only to those categories of the modern population who wish to use it for any outdoor work. Such plywood has the ability to boast of having good resistance, and for this reason, it is advised to use it in order to manufacture a certain kind of frame structures.

An alternative to using these building materials

If you are not obsessed with purchasing any of the aforementioned plywood, then the most appropriate option would be to purchase FB labeled sheets. This plywood combines the advantages of using both of these materials. She has the ability to boast of having a really high performance, which are determined by the characteristics of its production. Such veneer is impregnated with a special bakelite varnish, thanks to which, really impressive physical and technical characteristics are provided!

A material tightly glued together from three or more layers of wood veneer is called a plywood sheet. The fibers in it are mutually perpendicular, which gives it great strength in various directions and a constant shape. Plywood is often used as construction material and for making furniture.

Characteristic

For gluing FC (plywood glued sheet), glue based on urea-formaldehyde resin is used. It is characterized by low moisture resistance and therefore is used as a base for parquet or laminate indoors with relative humidity, for wall decoration and furniture manufacturing. Such material is durable, which is especially taken into account when buying furniture.

FC - relatively cheap material and therefore is in great demand. Also in its production, silicate glue is used, which is the least harmful to human health. It is made from birch or alder, and a combination of these tree species is also possible. If the FC gets a large number of moisture, it may curl or delaminate after drying. Such sheets can be up to 40 mm thick and are divided into grades, depending on the presence of knots on the surface.

Very often in construction, repair, exterior and interior decoration, a material is required that is equally strong and lightweight, inexpensive and resistant to conditions. environment. Plywood meets all these requirements. In this article, we will consider in detail the types of plywood, its characteristics and the purpose of each type.

The familiar plywood

Plywood is a wood-laminated material with at least 3 layers. Layers are veneer or tree bark. During production, the veneer is placed in each layer perpendicular to the previous one, therefore, the density and strength increase, and the composition used for gluing the layers increases moisture resistance.

Kinds

Depending on the glue used

PSF (phenol-formaldehyde glue) - the highest level of moisture resistance. Due to harmful substances in the composition of the resin, it is not recommended for residential premises and furniture production;
FKM (melamine glue) - the average level of moisture resistance. It has a lower content of harmful substances, but also a lower resistance to moisture, so it can be used wherever there are no increased requirements for moisture resistance and toxicity;
FC (carbamide glue) - low level of moisture resistance. It does not contain harmful substances, therefore it can only be used in the interior decoration of residential premises, as well as kindergartens, rooms, furniture;
FBA (albumin casein glue) - non-waterproof plywood. It is environmentally friendly and can be used wherever it is not needed. increased stability to moisture.

Impregnation with bakelite varnish

Bakelized plywood (FB) should be singled out separately. It is impregnated with bakelite glue and has the highest level of moisture resistance and reaction to environmental conditions of aggressive environment. Can be used: at high/low temperatures; from tropical to northern climates, with constant exposure to sea water, microorganisms, etc.

Because this building material is quite expensive, for the convenience of buyers, they are divided into several subspecies: according to the composition of the resin, as well as according to the method of sizing, so that each person can choose the right brand and not overpay in vain:

FBS (impregnation with alcohol-soluble glue), the main advantage is moisture resistance:

FBS brand: all layers of veneer are completely impregnated, the highest quality of the material;
Brand FBS-1: layers are not impregnated, but only smeared, the quality is slightly lower;
FBS-1A brand: only longitudinal layers are smeared.

Waterproof material

FBV (impregnation with water-soluble glue), the main advantage is strength:

FBV brand: only the outer layers are impregnated, and the inner ones are smeared;
Brand FBV-1: veneer is only smeared.

Surface

Surface treated plywood

Types of plywood for surface treatment:

Laminated. To enhance all the qualities of wood, the outer layers are covered with a special film, in order to additionally protect the surface;
Sanded on both sides (W2);
Sanded on one side (W1);
Unpolished (NSh).

The surface of the plywood is sanded to remove defects and make it more aesthetically pleasing.

Basically, sanded and laminated are used for finishing or decorative finishing, as well as for creating furniture front parts.

Grade classification

How to find out the variety of fvnera

Grade E (elite) - defects are not allowed, except for minor changes of an accidental nature in the structure of wood;
Grade 1 - the maximum length of warping or cracks should not exceed 20 mm;
Grade 2 - cracks up to 200 mm are allowed, wood inserts, glue leakage up to 2% of total area sheet;
Grade 3 - up to 10 wormholes are allowed. per m2, with a diameter of each not more than 6 mm; the total number of listed defects cannot be more than 9;
Grade 4 is extremely low quality. It may have the following defects: partially intergrown and dropped knots - without limitation; wormholes up to 40 mm in diameter without limitation; sheet edge defects up to 5 mm deep.

Application in construction

Thus, the grade of plywood depends on the presence of defects and their number on the surface of the wood veneer. At the same time, all types of plywood are used:

Grade E and Grade 1: decorative trim, finishing internal and external finishing;
Grade 2 and Grade 3: rough finish, or finishing, with additional application of varnishes and paints that mask defects;
Grade 4: rarely - internal rough finish, mainly used for the manufacture of containers, packaging.

At the same time, the marking on the label can be, for example, like this: 3/4 or 4/4, which means that the quality of one grade is on the outside of the sheet, and another grade on the inside. These products are very popular in Russian market, because For the price, it's much better.

Division by type of wood

According to the type of wood veneer, there are three types: birch, coniferous and combined. In this case, look only at the composition of the outer layers.

Hardwood

Birch refers to the hardwood type of construction plywood. Birch bark veneer is a very durable and dense material that has a uniform structure.

On the topic - what advantages does it have over coniferous.

The density of such plywood is approximately 650 kg/m3, i.e. a sheet of such material is 20% stronger than a similar one from another type of wood, but it does not contain natural resins at all, and it costs more.

Mainly used where required. unique properties wood: strength and lightness. This is, first of all, large-scale and private construction, as well as car building, the automotive industry, shipbuilding, and packaging production.

From coniferous trees

Layers of such plywood are made from the bark of coniferous trees (in Russia, they are mainly made from spruce and pine). It is not as durable as birch, but it weighs 20% less, contains natural resins in the wood, which naturally protect against decay and dampness, and also has a beautiful surface pattern, and is cheaper than hardwood.

Because the main advantages of this plywood are price, weight and beautiful surface, then it is more used in private construction (roofing, partitions, flooring, external and interior decoration etc.), as well as for creating decor items and in design.

From various types of wood

Composite plywood layers may consist of different varieties wood, both coniferous and deciduous. In terms of quality characteristics, it is closer to birch, but it costs less. It is used both in construction and in furniture, packaging production, etc.

By destination

Also, it is very convenient to classify plywood according to the methods of application, which we will consider below.

Application in shipbuilding

This type of birch plywood is also called "marine". Consists of brand FB, i.e. it is impregnated with the most moisture resistant bakelite glue under high pressure and temperature. Therefore, it can be successfully used in the construction and decoration of ships, boats, yachts and other watercraft, as well as wherever a material is required that can withstand heavy loads and not deform from decay during long-term operation in conditions of constant humidity: ports, docks, piers and other structures.

Furniture

Plywood furniture

Furniture plywood, of course, must meet certain requirements, especially for children's institutions. This is, first of all, environmental safety (the absence of substances harmful to humans), strength (furniture, during operation, usually has considerable loads) and a beautiful appearance. All these requirements are met by birch plywood FK, since its strength is higher than that of coniferous plywood, and it is impregnated with non-toxic carbamide glue. For front sides furniture is better to use the first and second grades.

Construction plywood is mainly 3/4 and 4/4 plywood, which is used in internal hidden works: pre-finishing of floors, ceilings, walls; building interior partitions, decking, podiums; leveling the "rough" floor, frame for stretch ceiling etc. Due to its lightness, strength, heat / noise insulation properties, ease of use, and also low cost, it is used wherever there are no increased requirements for a beautiful appearance.

Aircraft use

This type of plywood is made from the FSF brand, impregnated with formaldehyde glue under special conditions, as a result, in terms of strength and moisture resistance, it is sometimes compared with steel, because, having a high density, it easily resists prolonged mechanical stress. Such qualities are required in order to apply it in the most critical industries: the construction of aircraft, helicopters, large and small ships; in the wagon building and automotive industry.

formwork

Shuttering plywood is used in the construction of a concrete foundation, so it must have exceptional qualities in terms of strength, moisture resistance, resistance to adverse environments and various deformations (swelling, drying out, cracking, etc.).

We wrote about the main advantages in the article, with all the characteristics and strength indicators.

All the specified quality requirements are met only by laminated birch plywood FB with a maximum number of layers (thickness 18 mm for walls and 21 mm for the floor). The process of laminating sheets with a protective film greatly enhances the main qualities of this building material: the density approaches almost 700 kg / m3, and the maximum strength is: along the fibers at least 55 MPa, across the fibers - at least 25 MPa. Thanks to these qualities, this material is wear-resistant and economical, i.e. after the foundation has been erected, the sheets can be reused many more times.

Plywood for decoration

Decorative plywood has the FK brand and is made from various types of wood, but, of course, from elite or first grade, because. it is the naturalness of the surface pattern that is valued. Also, to preserve the appearance and other valuable qualities of wood, it is either laminated or coated with a special varnish. Main application: exterior and interior fine decoration, decoration, interior design, furniture, DIY crafts, etc.

Car body coating

It is also called "automobile" - it is laminated or mesh-ribbed (if you need a minimum of slip) FSF plywood. Such plywood is used for the manufacture of various parts of trucks: upholstery of the metal frame of vans, flooring, door upholstery, etc. Due to the strength and moisture resistance, such parts long time can be operated without fear of deformation or wear. Also, the advantages include ease of installation - almost all work can be done by hand and with low cost time.

Dimensions and thickness

If you have decided on the type, purpose and grade, then the further parameters for choosing and buying plywood are the thickness and dimensions of the sheet, because. this depends on the cost.

According to GOST standard sheet dimensions: 2440 x 1220 mm, but at the same time, the most popular and convenient to use is: 1525 x 1525 mm. Such sizes are also offered, such as: 1500 x 3000, 1525 x 3050 - in various variations of length and width, as well as non-standard sizes (determined by a specific manufacturer).

Dimensions according to GOST

The thickness of plywood from different manufacturers varies significantly within 3-30 mm, and depends on the raw materials used in the production and the number of layers in the product (from 3 to 21).

Manufacturing methods

The bark of trees is used to make plywood. Logs are pre-soaked in water and steamed. After that, the veneer is cut in several ways: planing, sawing and peeling. Peeling is considered the most effective way, because the thickness of the cut bark is minimal and wood raw materials are consumed in an optimal way. This process takes place with the help of a rotating machine, on which a tree trunk is clamped. In this case, the rotation occurs around the knife, cutting the bark in a circle.

Next, the cut bark is sorted, depending on the defects present, into quality grades, and processed in a special way to form sheets. After that, the sorted sheets are impregnated with glue and pressed. At the same time, each layer is perpendicular to the next, which provides special strength. The final part is surface treatment by lamination or sanding. Then, finished products undergoes quality control, labeling and packaging.

So, we examined in detail the types of plywood by grades and types of wood, as well as the application of each type. Among such a variety of different brands, everyone can choose the best option in terms of price and quality. Summing up all of the above, it is safe to say that if you need an easy-to-use, affordable, durable, lightweight, environmentally resistant wood building material, then plywood is your best choice.

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