What is foam made of? Influence of composition on quality. All about polyurethane foam Do-it-yourself polyurethane foam

Any installation work that involves the use of mounting foam requires certain temperature conditions for its implementation.

The optimum temperature for installation work should be from five to thirty degrees with a plus sign. Such conditions contribute to the best solidification of the mounting foam (or its polymerization).

Although in modern construction special mounting foams are already used for the cold season. How is it necessary to apply them and what are the requirements for this? Let's consider these questions in more detail.

Surface preparation

To carry out work with mounting foam, it is necessary to properly prepare for this procedure. To do this, you need to wear special gloves on your hands, because the mounting foam becomes hard to wash off when it hardens.

The use of mounting foam for sealing gaps requires compliance with certain requirements. In particular, before applying this composition to the area requiring such treatment, it is necessary to moisten it well with water. For better wetting, it is better to use a water sprayer.

Such a procedure is necessary in order for the foam to lie better on the surface (improvement of the so-called adhesion). The most optimal conditions for fast and effective foam hardening are characterized by rather high humidity levels (about 60-80%), as well as positive temperatures within 20 degrees Celsius.

The use of mounting foam

Before use, it is necessary to bring the mounting foam to a homogeneous state. As a rule, foam is sold in special cylinders that are attached to the gun. Therefore, before spraying, it is very important to shake the can thoroughly (it is advisable to mix the contents in the can for at least one minute).

Cheaper options come with a tube. After achieving uniformity, it is necessary to remove the cap from the can, under which the adapter for the spray tube will be located. The tube is supplied with the cylinder and must be screwed to the adapter after removing the protective cap.

After carrying out such procedures, it is necessary to turn the balloon upside down. This is the starting point for further work. The mounting foam from the cylinder is displaced by means of a special gas, which is much lighter than other constituent elements. Therefore, it is in the inverted position that all the components of the foam in such a cylinder are best mixed.

It is also possible to spray the mounting foam with a special spray gun. If you are processing vertical slots, then you need to start such work from the bottom of the slot, while moving up.

Foam consumption

One of the issues when using mounting foam is the consumption of this material. It is usually recommended to foam all the cracks not to the full depth, but only to one third. This is done because the foam in the process of filling the gaps increases its volume by about three times.

After applying the foam, it must be additionally sprinkled with water. After half an hour, the mounting foam in the gap will dry out somewhat and settle. And if you notice its insufficiency, then it will be possible to carry out additional spraying.

If the foam in the end is more than enough, then you can then cut it off with a sharp knife or blade. However, remember that this amount of foam residue is considered overrun, so spray in such a way that overrun does not occur.

Protecting Foamy Areas

Drying of the mounting foam occurs gradually over eight hours. Polyurethane foam reacts very negatively to ultraviolet radiation - in direct sunlight it eventually turns into dust.

For this reason, after its complete drying, it is necessary to carry out additional protective treatment. Mounting foam can be sealed and protected in several ways.

Polyurethane mounting foam is an excellent sealant and insulation. It is used both for the installation of such large-scale structures as doors and windows, and for the repair of minor defects. This material is used to patch various cracks and crevices, restore tightness at the joints, and even make other building materials. Foamed polyurethane is quite easy to use, but you need to follow certain rules for working with it, be quite careful so that the seam is even and lasts a long time.

Peculiarities

The hardened polyurethane foam is an elastic solid material of a yellowish-white color. This very light substance has excellent heat and noise insulation performance. It very quickly loses its properties under the influence of ultraviolet radiation, therefore it is mainly used indoors.

Such foam has a number of advantages that favorably distinguish it from other materials:

increased moisture resistance, high rates of sound and heat insulation;
low current conductivity, which allows it to be used in the installation of electrical networks;
many types of foam are resistant to fire, which allows expanding the scope of its application;
after exiting the cylinder, such foam expands in volume and fills even those microcracks into which it is impossible to insert a gun tube;
polyurethane can be used to glue surfaces made of different materials, such as wood or brick;
the foam is completely non-toxic, while being resistant to chemical attack.

Almost all of the above properties must be specified by the manufacturer in the appropriate certificates, which can be requested from the seller.

The following information should be printed on the packaging itself:

foam expansion volume. It can be from 10 to 300%, but most often, in fact, the foam still turns out to be somewhat less, since this percentage is indicated for ideal conditions;
its viscosity;
the volume of the container itself.

Most often, all these characteristics depend on the type and purpose of the foam, so you need to know which polyurethane and what it should be used for.

Release form

All types of polyurethane insulation differ in several criteria.

Depending on the method of application and the form of release, they can be of two types.

Professional foam is produced in special cylinders that are inserted into a plastic gun with metal clips. Such a gun allows you to use polyurethane economically and in equal portions. The main thing is to thoroughly rinse the device after use so that the remnants of the substance in it do not freeze.
Household foam packs are equipped with a small tube instead of a gun, which is put on the lever. It is not suitable for large repairs, but it will perfectly cope with minor flaws.

Depending on what time of the year and at what temperature the polyurethane will expand and solidify, the following types of mounting foam are distinguished:

summer - used at temperatures from +5 to +35 degrees;
winter - used at temperatures from -18 to +35 degrees;
universal - it costs much more, but it can be used all year round.

It should be noted that the temperature ranges are indicated not for air, but for the surface on which the composition will be applied. The lower its temperature, the less will be the expansion of the finished layer.

In addition, foam may vary in types depending on the flammability class:

B3 - combustible substance;
В2 – self-extinguishing substance;
B1 - refractory compositions.

Finally, mounting foams differ in composition. They can be one- or two-component. However, the latter type of foam is so difficult to handle that it is practically not used for private construction and do-it-yourself renovation of the premises. Two-component foam hardens in a quarter of an hour and there is practically no time left to eliminate defects, therefore only experienced professional builders use it.

Scope of application

Most often, mounting foam is used in the process of installing windows and doors, laying electrical wiring and pipelines. Due to the high thermal insulation in this way, it is possible to foam seams and recesses in cooling and heating systems, cracks in the roof and when insulating the surface of walls, floors or ceilings. It perfectly fastens wall panels and foam boards, providing excellent waterproofing. It is applied outside steel baths or cast iron baths to reduce heat transfer from the metal when the bath is filled with hot water. With the help of polyurethane, you can insulate the space behind the sheathing of PVC panels. In almost half of the repair processes, it remains an indispensable material.

In order to avoid any problems both with minor and major repairs of your own house or apartment, you need to be able to use both professional and household mounting foam. To work correctly with the first, you must correctly install and use a special construction gun.

Gun installation includes the following steps:

to begin with, the foam balloon is heated in warm water to room temperature, after which it is vigorously shaken for 30 seconds. This will give the polyurethane a homogeneous state, which will allow it to exit the cylinder smoothly and in full;
the protective cap is removed from the upper container of the gun, it is turned with the handle down and the cylinder is screwed into it. The container is screwed in with force until a hiss appears, which means that the mixture has begun to flow into the tool;
if the gun was previously used and was not washed well, then hissing will not be heard and you will have to purchase a new tool;
the system of connected elements is shaken strongly a few more times, turn the adjustment screw a quarter of a turn and, holding the trigger, begin to apply.

Working with such equipment does not require specific skills, but will require considerable dexterity if this is the first time.

Applying foam from a gun is carried out as follows:

first you need to clean the work surface from dust and dirt, then lightly wet it with a conventional sprayer, since the foam interacts better with a wet surface;
the tool nozzle is directed to the surface;
foam is supplied in the right amount by smoothly pressing the trigger;
to pour the composition into a vertical recess, it must be applied from the bottom up;
wide spaces are filled with zigzag movements by no more than a third of the volume, since the foam expands greatly in air;
it is better to supplement the area after than to cut off the excess of the solidified substance.

The gun barrel is quite long by itself, but in order to glue materials in hard-to-reach places, for example, to fill the voids between a false wall, you should additionally purchase an extension hose that is put on it.

Despite the fact that the packaging most often indicates a hardening time of up to 8 hours, in fact this process can take up to half a day. After complete solidification, the excess is cut off with an ordinary clerical knife or a metal file.

Unlike a handy construction gun, household polyurethane foam is equipped with just a small PVC tube, which is put on the adapter. In principle, the sequence of work itself is practically the same, however, more efforts will have to be made to fill the gap of the same volume. Such a tube is convenient for small volumes of work, because with it it is impossible to release the solution in equal portions. In addition, the balloon has to be constantly kept upside down, which is why the arm is constantly numb, so it is difficult to maintain smooth movements. If such a tube and adapter were not sold complete with polyurethane insulation, then you will have to buy them separately.

You will learn more about how to use mounting foam from the video.

Most often, mounting foam is purchased in the right amount at a time and after use, even if it is unfinished, it is thrown away. And also it is not bought in advance, as it has a limited shelf life. It is worth considering in more detail the nuances described below in order to be able to save.

Can it be applied multiple times?

It is widely believed among buyers that professional foam with a gun can be reused, but a household variety with a flexible tube, alas, is disposable and cannot be reapplied to the surface. Indeed, most often, if you leave the cylinder on the gun and block the trigger with a dispenser, the gun will not allow air to enter the cylinder and the composition will not harden. At the next use, it will be enough to remove the remnants of the hardened foam from the nozzle and you can start working again. However, exactly the same can be achieved from a household remedy. To do this, you need to start releasing foam from the cylinder, but, without letting it go out, bend and pull the soft tube with a wire. The foam at its end will harden, but the fold will not allow air to penetrate further and spoil the entire volume of the substance. At the next use, the cured edge of the PVC tube is simply cut off and the foam is ready for use. The container can be stored in this form for no more than a few weeks.

Polyurethane foam is one of the most popular materials on the market. We have made a selection of various tricks and life hacks that will make working with it easier and more comfortable, as well as find new areas of application for it.

The main components of polyurethane foam are polyol and diisocyanate, as a result of the reaction of which a prepolymer is formed. Moisture, which is usually taken from the surrounding air, is required to harden the mounting foam. According to certain calculations, it takes about 40 ml of water to harden the foam from a 750 ml can. Based on this, we can draw the first conclusion that the presence of moisture (up to a certain threshold) contributes to the rapid hardening of the foam and prevents its further expansion. Therefore, it is recommended to pre-moisten the places where the foam is applied with water. In addition, this will improve the adhesion of the foam to the applied surface.

The long-standing love of rodents for polyurethane foam, which they easily turn into dust, is known. But at the moment, compositions began to appear on the market that rodents do not like.

Since the foam bottle must be held upside down during operation, even cracks in the ceiling or in any hard-to-reach places can be easily processed with a PVC tube extension.

Acetone, as well as solvents based on it, can easily clean the surface of uncured foam. But with a frozen one, such a number will no longer work.
The older the foam in the can, the higher its viscosity. Accordingly, its expansion coefficient and the final volume decrease. In order for the viscosity of the foam not to grow so quickly over time, manufacturers make special additives, so it is recommended to shake the contents of the cylinder well before starting work.
The gun will allow you to more precisely dose the foam, thereby you will get additional convenience and savings. It will also come in handy for a large amount of work. High-quality models can be left without washing for a month or more. In other cases, a bottle with a special flushing liquid should be used.
In the assortment of some manufacturers there are cylinders with black foam. It's also great for landscaping. For example, to fix stones on an alpine hill. As long as it is not exposed to direct sunlight.

If you need to apply foam in several layers to close large openings, manufacturers recommend waiting an hour or two between laying each new layer. But if each layer is slightly moistened with a spray bottle, then the waiting hours can be reduced to 10-15 minutes.
In the absence of an appropriate filler, polyurethane foam will also help when transporting fragile items. To do this, line the box with cling film, fill it a third with foam, put a layer of film on which to lay a fragile thing. Then on top is another layer of film, which is also covered with foam. As a result, the foam will easily separate into two parts, which will simplify unpacking.

For foaming cracks in window and door openings, foam with a minimum coefficient of expansion should be used, otherwise it may be difficult to open windows and doors. Typically, such foam is labeled as window foam. But if this was not at hand, it is better to apply the foam in two layers. First, a small amount of foam is placed deep into the gap, to which, after the final expansion and hardening, another layer can be added if necessary.
In the absence of acetone, you can rinse the plastic nozzle tube with a carburetor cleaner (it also contains acetone). You can get it at any auto parts store. But this must be done immediately after use, until the remnants of the foam have hardened.

Winter foam can be used at temperatures up to -10 C°, and some types even up to -20 C°. But at the same time, the foam cylinder itself must have a temperature of at least +5 ° C. Hot water can be used to quickly heat the cylinder, but under no circumstances should it be placed in an open fire or other methods of rapid heating should be used. Otherwise, the result can be sad.

You can get rid of spilled or splashed foam after it hardens with the help of special cleaning gels designed for foam. They soften it, after which the foam can be easily removed.
When working with foam, do not forget to wear gloves, otherwise the foam that gets on the skin will leave stains on it for a couple of days.

Sealing agents are indispensable in construction. The most popular among them are sealants and polyurethane foam. Many people still confuse these types of sealing mastic, thinking that they are one and the same. Actually it is not. Mounting foam is not a sealant in the full sense of the word. Mounting foam is used to seal seams and joints with a width of 3 cm. Sealants are used to seal joints and seams no more than 3 cm

Polyurethane foam, in turn, is a stable chemical structure, with a low own weight and a high internal concentration. Mounting foam is sold in metal aerosol cans. Shake well before use. One cylinder gives up to 40 - 45 liters of finished foam. Mounting foam hardens under the influence of air moisture. In the process of hardening, the mounting foam increases significantly in volume, forming a porous mass with excellent heat and sound insulating properties. Mounting foam is used for gluing, fixing, sealing seams, heat and sound insulation.

Polyurethane foam can be professional (pistol), semi-professional, summer, winter and all-weather.

Polyurethane foam (abbreviated MP) is sold in cylinders containing a liquid prepolymer and a propellant (propellant). When the contents "leave" the container under the influence of air humidity and surface moisture, a polymerization (hardening) reaction occurs. The result is a fairly rigid polyurethane foam. Here are the main properties of foam, for which builders appreciate it so much:

assembly (attaches, connects separate parts of the structure),
soundproof,
heat-insulating,
sealing.

In addition, polyurethane foam has other unconditional advantages.

First, the MP, expanding, fills all hard-to-reach cavities and joints.

Secondly, it is self-hardening, so it is convenient and easy to work with it. For comparison: earlier, instead of foam, cement and tow were used for such work. First, the cement was diluted with water, then it was mixed with tow. In a word, the installation process was long, multi-stage and often ineffective. Now, one can of polyurethane foam is enough to get the same result without much effort and even better.

Thirdly, MP is a universal material: more than a thousand options for its use in construction and industry are now known.

Another indisputable advantage of mounting foam: it is designed to work with all traditional building materials (wood, stone, concrete, plaster, metal, glass). The only exceptions are polyethylene, polypropylene, teflon, silicone, etc.

The use of mounting foam

Polyurethane foam has occupied that part of the market, which before its appearance was dominated by traditional materials - cement, corks, bitumen, mineral wool tapes, plaster, etc. MP has established itself as a universal insulating material, filling cracks, gluing surfaces, moisture-proof, conductive electricity, fireproof (this indicator depends on the flammability class of MP). All this makes it possible to widely use polyurethane foam for sealing and soundproofing, gluing materials. So, let's take a closer look.

Insulation (sealing)

Filling cracks in cold rooms (insulation);

Filling cracks and crevices in roofing materials;

Filling voids around window and door frames, as well as other structures;

Gluing

Fixing door and window blocks (and then you do not need to additionally screw or nail with screws or nails).

Fixing insulating and insulating materials on the walls (if it is necessary to insulate the room, for example, with foam plates, the question often arises: how to glue the plates to the wall? The simplest solution is mounting foam).

Soundproofing

MP allows you to reduce the noise that occurs during the operation of pipelines, air conditioners or space heating systems. Foam close up the junction of hoods and air conditioners, the gaps between the pipes. And if there are no cracks, then there will be no rattling and noise. The use of foam in everyday life

Installation of window and door blocks.

Filling cracks and voids during repair and construction in country houses and city apartments.

Wide range of applications during indoor renovations (e.g. fixing wall panels, etc.).

Polyurethane foam can be used to seal cracks and holes on floating craft (boats, rafts, etc.)

As you can see, the possibilities of polyurethane foam are not limited. The only thing is that you need to know how to use it correctly. And for this we advise you to carefully read the instructions for use. The final result depends on how competent your actions will be.

Mode of application.

Professional. This name is more common. Manufacturers call it pistol foam. It differs only in the presence of working cylinder valves, that is, pistol foam is used with a special mounting gun. A mounting gun is a device that is put on a special cylinder valve designed specifically for it, thanks to which foam is supplied and dosed into cavities and crevices. Why is it still "professional"? Yes, because such a mounting gun costs 10 or even 15 times more than the foam cylinder itself. And there is absolutely no point in acquiring it for one-time housework. Such pistols are used by professionals, namely builders and repairmen who have to work with polyurethane foam sealants on a daily basis.

It is much more convenient to use the assembly gun thanks to the ergonomic handle and the dispenser trigger, in addition, the gun has a long metal barrel, which allows you to work in hard-to-reach places. But caring for the gun requires additional costs, after each use it must be washed with a special cleaning agent, which frees the working cavities of the device from the remaining foam that has not yet hardened in it. The cleaning agent itself is also under pressure in a bottle that has special nozzles that make it easier to clean.

Semi-professional. Mounting foam, the use of which does not require any additional devices (mounting guns). To spray polyurethane foam, a special plastic tube with a lever (adapter) attached to each cylinder is put on the valve. It is quite convenient and practical for a small amount of work. If you have not used up all the foam from the can, then the tube can be removed, washed with acetone or a special cleaning agent and set aside with the unused can until the next time.

Use temperature

Summer foam. The temperature indicated on the cans is from +5°C to +35°C, which means that the temperature of the treated surfaces must be within this range. But this does not affect the temperature resistance of the hardened foam in any way - both for summer and winter it ranges from -50 ° C to + 90 ° C.

Winter foam. The operating temperature of this foam is between -18°C (-10°C) and +35°C. It should be noted that the volume of foam after its spraying and expansion (foam output) decreases in proportion to the decrease in ambient temperature. For example, the foam yield from a 300 ml cylinder at +20°C is 30 l, at 0°C - about 25 l, at -5°C - about 20 l, at -10°C - about 15 l.

All season foam. It has absorbed all the best from summer and winter modifications, its special formula allows you to get a large foam yield, a fast polymerization process and work at low temperatures down to -10 ° C with an unheated cylinder. All-weather foam is a novelty and therefore is not present in the product range of all manufacturers of polyurethane foam.

Cylinder capacity

The output of foam from a cylinder designed for use with a mounting gun is more abundant than from a conventional cylinder of the same volume, due to the higher pressure in the cylinder, which allows filling a large amount of starting material.

300 ml - foam output up to 30 l, which makes it possible to process one standard door frame with a gap of three to five centimeters.
500 ml - foam output 35-40 l, under the same conditions - one and a half door frames.
750 ml - foam output up to 45-50 l - two or two and a half standard door frames.

Here are a few tips that will help make it easier to work with mounting foam and get the desired result.

Preparation for use. Since the polyurethane foam sealant in the cylinders hardens under the influence of air humidity, it is advisable to additionally moisten the surface with water before application: the expansion and the rate of foam solidification (polymerization) will increase.

When working with polyurethane foam is carried out at sub-zero temperatures, the surfaces to be treated must be cleared of ice and frost.

Before use, the bottle should be shaken well for about a minute and warmed up (without using open flame! Flammable!) to room temperature (from +10°С to +25°С). These measures greatly increase the yield and density of the foam.

If you plan to process window and door frames, additional spacers must be installed in them to prevent distortion, which should not be removed until the foam has completely cured.

Usage. When spraying, the container must be held upside down, otherwise all the air will come out and the container will remain without pressure, thereby becoming unsuitable for use.

The joint is filled from bottom to top with uniform V-shaped movements, leaving about half the volume of the gap for the foam to expand.

Cavities deeper than 50 mm are filled in several stages, waiting for each layer to dry.

Keep in mind: despite the fact that mounting foam has strong adhesive properties, it is not designed to work with polyethylene and silicone surfaces. It simply does not stick to these materials.

After application. Uncured foam from clothes and other items can be removed with acetone or a specially designed cleaning agent.

The average time for the initial drying of the foam (can be touched) is about 10-20 minutes. The foam finally hardens in 4-6 hours, this time directly depends on the temperature and humidity of the surrounding air.

Excess, protruding fragments of foam can be cut off with a knife.

The cured foam does not withstand exposure to sunlight, therefore, during outdoor work, after the final hardening, it must be additionally protected with paint or plaster.

Additional Precautions

Uncured foam irritates the skin, respiratory tract and eyes. Therefore, during operation it is necessary to use protective gloves and goggles, in case of insufficient ventilation and a high concentration of vapors - a respirator. Hardened foam is not harmful to human health.
When purchasing foam, you can stumble upon a fake. How to avoid it? After all, mounting foam produced in artisanal conditions without observing the necessary technologies may not meet the generous promises of the label. Unfortunately, we constantly hear about the discovery of another warehouse of counterfeit goods. It is worth recognizing that there is no unique, trouble-free way to determine a fake. All sorts of special signs and holograms are not a guarantee of quality, they are faked with great success by scammers, since these people learn about the mandatory presence of certain security signs on foam cylinders much earlier than us - consumers. It remains to use the general recommendations that are suitable for most consumer goods, namely:
- ask the seller to show a certificate of conformity for this product;
- look at the printing quality of the label or the quality of the image applied directly to the container. Since fakes are often produced at minimal financial cost, little importance is attached to the quality of printing. Therefore, the label (canister with the image) looks sloppy, and often a shift of colors is visible to the naked eye, due to which small text becomes fuzzy;
- pay attention to the date of manufacture (usually the expiration date of the foam is one year from the date of issue) - the expired polyurethane foam has most likely already lost all its valuable qualities.

Who produces it?

Our market is currently overflowing with all kinds of mounting foam, but this does not mean that all the products offered are of high quality. A lot of polyurethane foam that does not meet certain requirements enters the shelves of shops and especially markets: for example, when gases harmful to the ozone layer are used as a propellant. Or there are cases when manufacturers simply do not add mounting foam to cylinders.

Unfortunately, many Russian merchants (fortunately, not all) put the price in the first place, and not the quality of the foam sold. Yes, and our consumers "help" them in this. After all, an ordinary buyer has practically no idea what the foam should be like (how much it should be in a cylinder, what quality ...).

The composition of the foam includes a propellant, a prepolymer, and active substances. Therefore, it is worth forgetting about such a question as how to make mounting foam. This is still a technological process, home conditions will not work. In addition, some substances in the composition of the foam can cause irritation of the skin and mucous membranes, it must be handled with extreme caution. Anyone who has worked or who will work with foam should know how to remove mounting foam from skin or clothing. No matter how carefully you try to do the job, all sorts of situations can happen. We must be ready.

To clean your hands, you will need a special foam solvent, if one is not at hand, a solution of table salt will do. You should lower your hands into it, hold it for a while and then wipe off the remnants with a hard washcloth. After applying a specialized solution, wash your hands thoroughly with soap and anoint with cream. If damage has been done to clothing, it can be cleaned. First, cut off the main part of the foam with a sharp knife, then apply demixid, it will dissolve the foam and you can easily remove it with a napkin. Before such a miracle foam appeared on the market, similar work was carried out in many stages, because cement was used as the material.

The quality of work with the use of cement, in comparison with the results of work with the use of foam, cannot be compared. It will be inferior. Another advantage of the foam is its ability to harden on its own, it also penetrates into the smallest cracks. To date, there are about a thousand ways to use mounting foam. And this number will grow. Even if someone did not use the foam himself, they probably saw a yellowish mass protruding from the cracks of houses, windows or doors. These are the so-called surpluses that have crawled out, from an aesthetic point of view, they can be eliminated. How to remove the mounting foam, the person involved in the repair should take care of this.

Foam is used mainly for work related to sealing: installation of windows, doors. Mounting foam is able to penetrate and spread into hard-to-reach cracks, carefully envelop the entire space, and after a while becomes a fairly solid substance. You can buy foam at any hardware store or order it online. Foam is sold in a cylinder, no resources are required for its use, neither electricity nor special devices. Very convenient to use. How to use mounting foam is detailed in the instructions. There is nothing complicated in this process. When the foam is squeezed out under the influence of moisture contained in the air, a reaction occurs, and the foam gradually hardens.

Foam is used mainly for the purpose of sealing, as a heater, sealant, has sound insulation. In addition, it can be used to fasten structures. Another advantage of the foam is that it can be used when working with literally all materials (wood, concrete, metal, stone). But one should not forget about the possibility of deformation of the structure after using the foam; to avoid such a problem, spacers are used that hold back the onslaught of the foam increasing in volume. Mounting foam should not crumble after hardening and fit snugly to the surface, and not roll off it.