What is plywood fk and fsf. What is the difference between plywood FC and FSF? Division by type of wood

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? The tasks and some technical characteristics of the compared materials differ. 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 mission of restoration is impossible, the loss of appearance and characteristics occurs irrevocably.

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 the FSF-TV brand: 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 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 a building 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 is a 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 a large amount of moisture gets on the FC, then after drying it can curl or delaminate. Such sheets can be up to 40 mm thick and are divided into grades, depending on the presence of knots on the surface.

Today, the construction industry cannot do without such material as plywood. They produce products of various varieties and types, each of which has its own quality characteristics. Currently, there is a lot of controversy about which product is better than FC and FSF? To try to figure this out, you need to know the properties and characteristics of each type, and only then draw analogies and find common features and what is the difference between these materials.

Technical differences

Plywood FC

What is plywood? These are 3 or more sheets of wood veneer, which are joined using a gluing method.

Video: the difference between FC and FSF plywood

The video tells what is the difference between plywood fk and fsf:

FK and FSF plywood are high-quality products that are actively used in various areas of construction. There are certain differences between them, which are very helpful in solving the problem of choosing a particular material for certain jobs.

It describes how much OSB plywood costs

For example, FC plywood can only be used inside the house, where there is no strong influence of moisture, but PSF is not afraid of such an impact. Each of the presented options has its pros and cons, which must be taken into account when planning a variety of works.

Plywood FK and FSF are two options for one of the simplest, most affordable and durable materials that finds the widest application. They are equally well in demand in construction work, industry, the packaging industry, machine and car building. Due to their high convenience, there is practically nothing to compare them with, since they are suitable for floors, walls, ceilings, partitions. Not bad and as a basis for any design ideas.

What is plywood FK and FSF?

First of all, it is worth understanding the abbreviations:

1. FK - a wood-laminated board glued with a urea-formaldehyde composition, from where the given abbreviation "plywood + urea-formaldehyde glue" came from;
2. FSF is a material made by joining veneer with phenol-formaldehyde substances, which gives the combination "plywood + resin phenol-formaldehyde glue".

What is the fundamental difference?

The first is not at all resistant to a humid environment, but it is strong enough and versatile. Designed for dry conditions only. Much cheaper than the second option, therefore it is widely used for the production of furniture, wall cladding, the manufacture of packaging containers, as a substrate for laminate, parquet and other coatings.

Produced from peeled wood of birch, alder and some other hardwoods (their combination is also possible). After penetration of moisture, it usually delaminates and twists, which is a serious difference between FK plywood and FSF. In terms of thickness, such sheets can reach 40 mm. They are divided into varieties based on the presence of knots.

Pack of sheets of plywood FC

The second is characterized by increased resistance to moisture, which it resists very successfully. Thanks to this property, it finds demand in roofing processes, it can be used not only inside, but also outside buildings. It has good wear resistance and mechanical strength.

It is made mainly from birch and coniferous veneer. It can be impregnated with compositions not only against moisture, but also against fire (FSF TV), which is why it has an extended range of applications: construction, industry, mechanical engineering and aircraft building.

How to distinguish FK plywood from FSF externally?

Without experience in this matter, you can get confused, because by external signs they are not much different, which sometimes causes misunderstanding. The only factor that clearly shows the difference between them is the shades of the layers.

FC is lighter, as it is connected with glue without the presence of phenol, which is why the sheets on the cut are as close as possible to the natural color of the veneer. Whereas PSF with increased impregnation from moisture has a darker color with the presence of a reddish undertone.

Differences in physical and mechanical indicators

Which plywood is less harmful - FK or FSF?

For the manufacture of wood-laminated boards of the FK type, a silicate adhesive is used, which is non-toxic to humans and animals. This equates plywood with a safe building material suitable for interior decoration and installation of partitions in dry conditions.

PSF is more resistant to moisture, because it has a special impregnation based on potentially harmful resins. The glue also contains 8 mg/100 g of phenol, which has a negative impact on the health of others.

Main differences

To better distinguish between these two types of plywood, we offer a brief comparison between them.

So, FC is absolutely safe for health, unstable to moisture, suitable for interior work and furniture production, fragile and poorly withstands mechanical stress, easily breaks and delaminates.

While PSF has low environmental friendliness, which is why it can harm humans and animals, it has excellent moisture resistance, it is applicable for interior, facade, and any other external work, it has increased fracture strength and pressure.

Plywood is a demanded material used in construction, furniture production, technical and decorative products. There are several types of it, in which it is desirable to understand in order to acquire what you need. In particular, it is useful to find the main difference between FC and PSF plywood as the most popular materials.

Structure and main difference

Any plywood consists of layers of natural veneer, firmly glued together. Only the wood that is used to produce veneer differs, the method of arranging thin layers and the composition for gluing or impregnating. Sheet sizes do not depend on these parameters and may be the same for different types.

In FK plywood, the veneer layers are glued together with urea-formaldehyde glue. In PSF materials, gluing is carried out with phenol-formaldehyde adhesive resins. This is the fundamental difference between the types of FC and PSF, from which the corresponding consequences follow.

The external difference between FC and PSF is manifested in the color of the interlayer. The ends of FC plywood are lighter, while FSF has a reddish dark tint. This is explained by the fact that carbamide-based adhesive becomes transparent when solidified, while formaldehyde resins are colored.

The difference between FSF and FC is as follows:

• adhesive composition;
• moisture resistance;
• strength;
• end color;
• price;
• content of hazardous substances.

And it all depends mostly on the glue. The carbamide composition dissolves in water, so FK plywood products are afraid of getting wet. PSF, unlike FC, is a moisture resistant material.

Note! Noticeable difference in cost. With the same size and grade (quality), the price of PSF is usually higher than FC.

Of course, the cost will be affected by the place of production, additional processing and some other factors. But the general trend is still visible.

It should be noted that there is also another type of plywood - FOF. It belongs to the special purpose group. The difference between FOF and FSF plywood is that the former is covered with a durable laminated film. Thus, its moisture resistant properties increase even more.

Application of FC

FK plywood sheets are made from hardwood, mainly birch, poplar, alder. This is a wonderful material, the highest grades of which are distinguished by a light, even surface.

A feature of FC is that, due to the adhesive, it does not withstand prolonged exposure to moisture and, when wet, swells and delaminates. At the same time, if such plywood is used in a dry room, it exhibits high strength characteristics.

From FC plywood they make beds, sofas, boxes for transporting goods, upholster walls with it, put it on the floor under parquet or laminate. Like other species, its thickness varies, reaching a maximum of 40 mm. Varieties depend on the presence of knots, sprouting, cracks, darkening and other defects.

A question may arise, should FSF or FK plywood be used for flooring, for example, under parquet? These two types are suitable, although FSF moisture-resistant plywood products (low grade, sanded and unsanded) are preferable. The difference between them will also be in price. If the room is not damp, it is not a basement, not a basement, then in order to save money, you can use FC. Most often, when laying the floor, sheets with a thickness of 10-12 mm are used.

Application of PSF

FSF sheets are used as roofing material, for the construction of stages, sports grounds, temporary structures, billboards. Such plywood is widely used for formwork, and laminated material is the best option here, since it can be used several times (up to 100).

Although FSF is not made of residential furniture, it is great for garden benches, gazebos and other structures. Another common use is in the flooring of trucks and the upholstery of vans. From PSF sheets it is allowed to make boxes for the transportation of non-food products.

Security difference

There is another important difference between the materials under consideration. It concerns the safety of their production, use and disposal.

PSF contains phenol formaldehyde, which makes you think about the safety of the material. Phenol and formaldehyde, from which glue is made, are poisonous, negatively affect the skin, mucous membranes, and respiratory tract. Disposal of products with their contents is problematic.

As the phenol-formaldehyde resin cures, it becomes less hazardous, but both phenol and formaldehyde fumes are possible. Sanitary standards require monitoring of these parameters.

When buying, you should pay attention to the emission class of harmful substances. If the certificate of conformity is E1, then such plywood can be used even in the bedroom. Class E2 indoor use is prohibited.

Plywood FK is safe for indoor use, since urea-formaldehyde glue is an order of magnitude less toxic than phenol-formaldehyde. The emission of phenol in it is minimal.