Fill a seam, crack, install a window or door block, glue the insulation - for all these works and a dozen others, polyurethane foam is used. If you go to any hardware store, you will see at least a dozen items. And in large or specialized ones there can be hundreds. Which one should you choose? Which polyurethane foam is better? Depends on conditions, tasks and requirements.
What is polyurethane foam and how is it formed?
Polyurethane foam is a foamed polymer that quickly hardens (polymerizes) in air. Release form: metal cylinders of various volumes. The cylinder contains a prepolymer in a liquid state and a propellant gas. Substances called "propellant gas" are characterized by the fact that they have low temperature boiling. Created in a balloon high pressure. When the outlet valve opens, the composition is pushed into an area more low pressure. When released, the propellant gas boils, forming a large number of air bubbles and inflating the foam.
The choice of polyurethane foam depends on the conditions and tasks
Next, in air, the resulting foam polymerizes - it becomes rigid and hard. The curing process requires water, so it is recommended to wet the surfaces before application. Moisture is also taken from the air. Since there is little moisture in frosty air, there are certain compositions for such conditions.
Properties
Do not confuse polyurethane foam with glue. By the way, there is glue in similar containers that also foams. But there is a completely different composition and nothing can be securely glued to the mounting foam. It can support/hold in a certain position, but none has the strength of an adhesive connection. So don't be confused. This is not its area of application.
How to understand which polyurethane foam is better? You need to know its properties
To correctly understand where polyurethane foam can be used, you need to know about its properties. They are very good:
- Mounting property. This is tying, connecting, attaching (not gluing) parts of a structure.
- Soundproofing. Polyurethane foam cannot be called soundproofing, but it reduces the noise level.
- Thermal insulation. Due to large quantity air enclosed in thin polymer bubbles reduces thermal conductivity.
- Good adhesion to almost everything building materials. Cannot be used only with silicone, rubber, and some also with polyethylene.
The main use of construction foam is installation. It’s not for nothing that it’s called polyurethane foam. But it is also not bad as insulation and sound insulation. Not perfect, but not bad. Filling seams, cracks, sealing/thermal insulation of communication inputs - this is its area of application. In this it is difficult for her to find competitors. How were such gaps filled in the past? They hammered it with rags and covered it with mortar. Foam in this regard is much more convenient and has better properties.
Important Features
Any type of polyurethane foam has two important characteristics — primary and secondary expansion. Primary expansion is how much the mass increases in volume before the end of polymerization. There are foams with both high primary expansion and low ones. Which polyurethane foam is better - with large or small expansion? It’s impossible to say for sure. They are used in different cases. Low expansion foam is good for filling small cavities, as well as for layer-by-layer filling of deep seams, when installing EPS. Large expansion is more beneficial when filling cavities, using as sound insulation, thermal insulation.
Specifically speaking, for doors, it is better to take foam with low expansion. Moreover, both primary and secondary. Unfortunately, this is a professional foam, so you will also need a gun.
The left picture is an illustration of a large secondary expansion. Do you see how the primary frame has been torn apart? Well, the difference between foams is in density and “fluidity”
Secondary expansion is an increase in foam volume after completion of the polymerization process. Which polyurethane foam is better for this reason? Definitely the one with the smaller secondary expansion. Why? Because this process is difficult to predict. And the possible consequences are serious - deformation of flexible or moving parts. For example, a window frame or door jambs may bend if the foam increases too much. And even the spacers that are installed do not always help.
Why then do we need construction foam with high secondary expansion? It has its own area of application - filling cavities and cracks in rigid and stable materials and structures. For example, in concrete, as a filler with thermal insulating properties between the wall and the brick finish. Foam with higher secondary expansion is cheaper. For large volumes this is important.
Foam output
Another thing you need to pay attention to is the foam output. This is the volume that can come out of the cylinder. It is indicated in liters. Typically, the larger the cylinder, the greater the yield. But not always. With the same cylinder size, the difference in output can be about 20-30%. It can be determined by mass. The heavier the cylinder (weight indicated), the greater the yield will be.
As you can see, identical-looking cylinders contain different quantities foam
What else is worth knowing is that the actual yield of polyurethane foam is usually less than declared (this is more often the case with household types). To ensure the required volume, it is necessary to accurately select the proportions of the prepolymer and filler gas. And not all brands can boast of this. Here is a list of those who consistently produce the declared volumes:
- Soudal (Soudal) professional lines (not household).
- Penosil (Penosil) Gold (Gold) and Premium (Premium).
- Moment Installation (very inexpensive and widespread).
- Wellfoam (WellFom).
- Hilti (Hilti).
- Kim Tec (Kim Tek).
- Den Braven (Den Braven).
- Illbruck (Illbrook).
- Tytan (Titanium) (some batches either do not work at all or produce less than half of what was declared).
Perhaps there are others good brands construction foam. But these are the ones that, according to builders, very rarely fail. When purchasing, look at production date. After a year, the valve begins to poison, the filler gas comes out, and the output, accordingly, decreases.
In order for good foam to retain its properties, it must be stored correctly.
Note! You need to work with polyurethane foam, which has room temperature. In cold weather, you need to pre-warm it. Even winter or all-season.
Types and applications
All cylinders with polyurethane foam can be divided by area of application: household and professional. They are also different in appearance. Professional ones are made for a special pistol. It won't be possible to work without it. Household ones have a push valve (as in aerosols) and a long thin tube. Of course, these are not all the differences. There is a difference in properties:
- Curing speed. Professional ones harden faster. Some brands become hard after 30 minutes. “Normal polymerization time” is 24 hours. This is how long it is recommended to wait after applying the foam before continuing work.
- Amount of secondary expansion. For professional ones it is about 30-50% of the primary volume, for household ones it can be 130-250%.
- Dimensions of cavities. Foam consisting of small bubbles is considered good. This is what distinguishes professional ones, although some household ones also have few large cavities. But they are not cheap either.
Which polyurethane foam is better, we decide by characteristics
Of the entire list, the most unpleasant is the large secondary expansion. Why is this bad? Because when foaming windows, door frames, strongly expanding foam can bend the wood or profiles. Well, because it grows too actively, it is difficult to dose, which leads to large overspending. So the difference in price turns out to be quite insignificant. If it remains at all.
When and where to use these types of polyurethane foam? Household foam is also suitable for filling cavities and holes in rigid structures. For example, Boxer, Ultima, Cosmoflex, Wellfom, Storehouse. When installing doors and windows, it is better to work with a professional. These are Ilbrook, Penosil, Soudal, Titan.
Species by season
Polyurethane foam is divided into temperature conditions applications. There are the following types:
- Summer. Use at temperatures above zero, but not lower than +5°C.
- Winter. It can be used in frosts down to -18°C.
- All-season. Its stated range is from -10°C to +35°C, but it is optimal to use it somewhere in the region from +10°C to zero. At lower temperatures, winter is better, at higher levels, summer is better.
Which polyurethane foam is better: which one is suitable for temperature conditions?
In a heated room we use summer foam; if we foam windows in winter, we use winter or all-season foam, depending on the temperature outside. In general, the “specialized” one—summer or winter—performs better. They are adapted to certain conditions, and this is always more reliable than universal option(all-season).
When working in winter, do not leave the foam in the cold. Bring it into a warm place. If it gets too cold, it will be too fluid and will not hold its shape. In general, we always keep the foam warm. And one more thing - more foam comes out of a warm balloon.
By flammability
Polyurethane foam must also be selected based on flammability. There are three classes:
- flammable - the cylinder is marked B3;
- self-extinguishing (no fire, it does not burn) is marked B2;
- non-flammable (even in fire it retains its properties for a certain period of time) is designated class B1.
Flammable and non-flammable mounting foams. The degree of flammability is indicated by the letter B and numbers from 1 to 3. B1 - non-flammable, B2 - self-extinguishing, B3 - flammable
In wooden and frame buildings It is best to use non-flammable construction foam. It should also be used in rooms with increased requirements for fire safety. In houses there is such a room - . Every serious manufacturer has fireproof/non-flammable polyurethane foam. You need to watch it in a professional line. For example, Tytan B1, Soudal FR, Den Braven (Den Braven), Kim-Tec (Kim Tek).
There are also two-component polyurethane foams. But they harden very quickly, so they are used by professionals, and even then not all. You need skill to work, but two-component foam costs a lot.
Special types
There are some types of work that require special properties.
The brands listed are far from the only ones. There are others too. Look at serious manufacturers of construction chemicals, read the characteristics, look for reviews. We are already accustomed to the fact that the stated characteristics do not always coincide with reality.
Guns for professional polyurethane foam
If you decide to use professional polyurethane foam, you will need a gun for it. There is a wide range of prices here. But for one-time use, you can take an inexpensive one. The price does not affect the amount of foam. It’s just that the more expensive ones better control the intensity of foam output and deliver it over a greater distance.
Professional polyurethane foam requires a special gun
The ability to adjust the feed intensity is available in any, but the level of control is different. After use, if the cylinder is not empty, it can remain in the gun for 2 weeks or a month. During this period, you can simply continue working. But a “loaded” pistol must be stored in a warm room, not in direct sunlight.
When replacing the cylinder, if the foam flows normally, no additional manipulations are needed. If the foam stops coming out and the container is not yet empty, the nozzle may be clogged. Then the nozzle can be washed. If the liquid comes out without problems, then the problem is in the cylinder. Usually the propellant runs out prematurely, but the copolymer can also run out. After finishing the work, the cylinder is removed, the gun (nozzle) is washed with a solvent (spray foam cleaner). No other manipulations are required.
Polyurethane foam is widely used to fill voids and cracks, as well as to fix doors and windows in openings. The market today is overflowing with offers - eyes run in different directions from the abundance of manufacturers. In such a situation, it is very easy to take a low-quality product and throw money away.
How to choose the right polyurethane foam, photo quality material, leaders among manufacturers - later in the article.
Chemical properties of polyurethane foam
There are one- and two-component ones. A more convenient and common option is a one-component foam, polyurethane-based sealant. It consists of a prepolymer from a mixture of polyol and isocyanate, a propellant, that is, a mixture of liquefied butane and propane, which creates pressure in the cylinder.
As the composition is squeezed out, it reacts with air, expanding 15-30 times. Due to volumetric expansion and semi-liquid state, foam fills even hard-to-reach voids. Thanks to the water contained in the air, the foam hardens and becomes hard after a certain time.
To speed up the drying of the foam, the walls of the niche to be filled are moistened. Within 24 hours, the polyurethane completely hardens and gains strength.
The advantage of this material is that it is not afraid of water, and due to the pores in the foam it insulates heat very well. After hardening, it is not harmful to humans or animals.
Areas of use
It is not capricious in terms of application - it can be combined with metal, brick, and wood. Thanks to these properties, it is used for insulating seams, installing windows and doors, insulation, and sound insulation.
Manufacturers of polyurethane foam
The market is full of manufacturers, and everyone claims that their product is the best. The easiest way in this case is to use proven, reliable brands. The best in the field of quality foam production are:
- Finnish company Henkel;
- Dutch company Bison International;
- Belgian company Soudal;
- Estonian manufacturers Bau Master;
- Turkish company Soma Fix;
- Russian company "Master Nail".
Good foam, after being applied to a vertical or inclined wall, does not move down, but remains in place and begins to expand quickly. High-quality foam is a frost-resistant material and does not begin to crumble after exposure to cold.
Quality criteria
The most important property– foam expansion coefficient. At the same time, household foam shows much worse results than professional foam: 10-60% versus 180-300%, respectively. The expansion coefficient is determined not only chemical properties material.
Affect weather, speed of foam extrusion, use of a foam gun or the tube included with the balloon. The skill of the one who uses the foam plays an important role.
Manufacturers indicate the expected expansion coefficient on the cylinder. It differs from the actual one, usually to a lesser extent due to the non-ideal conditions in which the foam is used.
When filling cavities, you should follow this rule - approximately two-thirds of the cavity is filled. Then the foam, as it expands again, will fill the cavity, but will not begin to crawl out and put pressure on the walls.
This point is especially relevant when installing doors and windows - the frame is deformed under the pressure of the foam, and it may happen that the door or window stops opening and closing.
The density of the foam after it has completely hardened should be approximately 1525 kg/m3 for professional foam, and about 2535 kg/m3 for household foam. It is definitely impossible to say what is better - denser foam or less dense foam. To insulate seams, a denser option is better, but when filling large cavities, you simply won’t have enough dense foam.
Uniformity - when cutting the foam with a knife, it should be homogeneous in its mass, without large air cushions. The pores should extend evenly in all directions.
Criterias of choice
The choice depends on the nature of the work being done and how much foam is needed to complete it. Household foam has a lower container capacity and expansion coefficient, but its final density is higher, which is very good for sealing seams.
There is no need to buy a foam gun separately, which, if it is of normal quality, costs 2-5 thousand rubles - the container is equipped with a tube for applying foam.
Professional polyurethane foam is indispensable when working with large cavities, and due to the use of a foam gun, foam consumption is significantly reduced, and it is much more convenient to work with it than with a tube.
Photo of the best polyurethane foam
Polyurethane foam is a universal material that is widely used in construction for sealing joints, installing doors and windows, sealing cracks, and insulating walls. In construction stores, the assortment of polyurethane foam is represented by dozens of items. In this regard, the question arises - “which polyurethane foam to choose for specific work?”
What is it like?
Polyurethane foam is a two-component sealant based on polyurethane foam. Available in aerosol cans . Composed of polyols, methylene diphenyl diisocyanate and auxiliary substances - blowing agent, catalyst, stabilizer. In addition to the polymer itself, the cylinder contains gases, the task of which is to push the contents out under pressure. They also create bubbles that increase the volume of the starting material.
This sealant replaces cement, tow, and glue. To make sealing, it is enough to fill the space with the composition from the cylinder. Due to mechanical expansion, the polymer completely fills the voids and hard to reach places. Two-component options with a minimum coefficient of expansion are suitable for sealing small gaps and connecting fragile components.
How to work
Foam is difficult to wash off, so you need to work with it with gloves and very carefully. Before use, the container must be shaken well so that all its contents are well mixed. If this is not done, not foam will come out of the nozzle, but liquid resin. To ensure that it sets immediately, the surface to be treated can be moistened with water. When applying, the container is held with the bottom up so that the gas evenly squeezes out the polymer.
Foam is only effective when sealing cracks up to 5 cm wide, for spaces bigger size polystyrene is used. When working with the material, you need to have a rag on hand - if the sealant drips onto the floor or furniture, you can immediately wipe it off. Excess foam can be cut off within 30 minutes after application. This can be done with a wood hacksaw or a painting knife. The material is completely set and stabilized after 8 hours. In this condition it is suitable for plastering.
Polyurethane foam: how to choose
Execution option:
- Household (adapter) - is a cylinder with a tube. Suitable for those with no experience installation work. To use such products you do not need to use additional tools. IN household version more defects than in professional - most often this is non-compliance percentage gas with filler, smaller volume compared to declared.
- Professional - consists of a cylinder and a pistol mechanism that allows you to control the supply of foam. The polymer itself has a uniform structure and expands minimally at the exit. It has an expanded line of varieties, including fire-resistant.
If you are not a professional builder and you perform one-time work, then choose products household segment. If you are doing installation or performing large volumes of work, use foam with a special gun. It can be purchased at any hardware store, sometimes it is sold together with a cylinder.
Temperature:
- Winter - up to -20°C.
- Summer – from +5 – +35°С.
- All-season – from -10 – +30°С.
Fire resistance rating:
- Fire-resistant (B1) - suitable for the construction of baths, stoves, fireplaces.
- Self-extinguishing (B2) - do not contribute to the spread of fire.
- Combustible (B3) - budget-friendly, but the least safe to use.
When choosing an installation sealant, consider the manufacturer and version (household, professional). High-quality polyurethane foam has high viscosity, low secondary expansion, high density after hardening. By carefully studying the specifications contained on the cylinder, you can choose a really good product.
Anton Tsugunov
Reading time: 6 minutes
Properly selected and correctly applied polyurethane foam for windows is an important component of their quality installation. It is difficult to imagine installing modern PVC window structures without this easy-to-use and reliable material. A novice master will have to understand the differences and features of foam in order to choose a composition from the wide range offered by stores.
Properties and scope of material
Polyurethane foam is a liquid polyurethane solution pumped into a container under pressure. When exposed to air, it quickly hardens and at the same time increases significantly in volume.
There are 2 types of foam expansion:
- Primary (when the composition leaves the cylinder). Provides ease of use: the solution can effortlessly fill any shaped recesses.
- Secondary. Among the disadvantages: an increase in the volume of sealant during final polymerization can deform the window elements. Therefore, it must be taken into account when carrying out work.
Completely hardened material acquires unique useful qualities:
- Low thermal conductivity is achieved due to air bubbles located in the thickness of the frozen material. If not for the price, foam could well be considered as an alternative to conventional insulation materials.
- The presence of air voids increases the sound insulation of the entire window design: vibrations transmitted to the window are damped by foam. Thus, it complements the installed rubber seals, enhancing soundproofing.
- Cured foam does not allow penetration electricity, has water-repellent properties, not susceptible to rotting or mold.
- High adhesion rates make it possible to use foam as a fixing material: it securely fixes window or door frames, as well as other elements, in place.
- Depending on the brand, the composition does not support combustion or is completely resistant to fire.
Due to its special properties, the foam is ideal for outdoor and interior work. But, like any material, it has disadvantages:
- After hardening, the excess composition is cut off. And if the cut surface is not treated appropriately, then water will get into the open pores. Over time, this causes the material to deteriorate.
- The frozen composition does not withstand exposure to ultraviolet radiation, so it must be protected from direct sunlight.
- You have to follow the rules for storing cylinders: strictly in a vertical position at a temperature range from +5 ˚С to +25 ˚С.
The high adhesion of the foam allows it to adhere reliably to surfaces made of different materials. Therefore, you should work with the composition very carefully: if it gets on your hands or other parts of the body, you can only wipe it off with top layer skin, which will take at least a few days. When pouring, be sure to use gloves. You should also securely cover all surfaces on which the solution may drip.
If foam does get on the floor, furniture or other surfaces, it can be removed in several ways, which are described.
The use of this design provides the following advantages:
- The ergonomics of the gun allows the master to fill cracks with one hand. The second remains free, due to which you can work alone at certain stages.
- The gun makes it possible to accurately dose the volume of solution released. This reduces consumption by reducing unnecessary waste.
- A thin, long nozzle will easily deliver the solution into hard-to-reach cracks and holes.
- The cylinder can be used in any position.
- The reusable valve ensures the safety of the solution between repairs.
When choosing professional cylinders, you do not need to solve the frequently asked question: where can the remaining solution be usefully used?
- Professional compositions have the best performance characteristics than household ones. For example, they have a lower secondary expansion coefficient, which makes their use more convenient.
Techniques for pouring foam using a professional gun are shown in the following video.
Mr. Build strongly recommends: for installation plastic windows use only professional mounting foam. Secondary expansion will not create unnecessary load on the structure or displace frame elements. The density of the professional staff is maximum, and this will ensure best quality fastening, insulation and sealing of the seam.
Choose a gun based on budget, ergonomics and service life. For a single procedure, the cheapest one with plastic parts will do, but for professional use give preference to collapsible high-quality models.
Household foam has less outstanding performance characteristics: worse adhesion, a higher coefficient of secondary expansion, and less material yield from the cylinder. It is sold in containers equipped with a plastic tube for supplying the solution. It is screwed onto the valve before blowing begins. It is recommended to use the entire bottle at once.
Working with household foam is less convenient: both hands are used, and the can must be placed bottom up. This will ensure a more complete release of the solution. Use it with the utmost caution and at the least important places. Fill the seam to no more than 50% depth!
Soundproofing foam
If the windows themselves do not transmit noise, then the polyurethane foam on which they are mounted is an excellent conductor of noise, since it is light, hard, and has a closed cellular structure, which facilitates the unhindered passage of sound waves.
Compared to ordinary construction foams, the use of MAXFORTE SoundFLEX foam adds more than 10 dB to sound insulation, which is equivalent to reducing noise by 2-3 times.
The difference between regular mounting foam and soundproofing foam can be seen in the video:
If you squeeze a piece of polyurethane foam in your hand, it will simply collapse, unlike specialized soundproofing foam. Like a sponge, it will return to its shape. It does not harden and thus does not become a sound bridge.
Winter or summer?
Foam is divided according to the seasonality of its use. It happens:
- Summer, suitable for work at temperatures above +5 ˚С.
- Winter, allowing you to seal cracks at temperatures down to -18˚ C.
- All-season. Seen and used less frequently. Professionals advise using it during transition periods in autumn and winter or getting by with the first two varieties.
Flammability of foam
The compositions also differ in flammability parameters:
- B1 – the highest fire safety class, does not ignite even upon contact with open fire.
- B2 – does not burn on its own, without an additional heating source. Such compositions are called self-extinguishing.
- B3 – lowest flammability class. This material is not recommended for use, especially in residential areas.
Rules for choosing foam for installing PVC windows
The composition most suitable for a particular case is selected. What to look for when choosing?
- The temperature at which the cracks will be sealed. It is used to choose winter, summer or all-season foam.
- On the secondary expansion coefficient. The lower the value, the better. It is recommended not to use formulations with an indicator of more than 15–20%. Professional foam easily fits into such a framework, but with household choice should be done carefully.
- For expiration date. No one can predict how the behavior of the solution will change after storage time. It's better not to take risks.
- To the fullness of the cylinder. Underfilling is a common occurrence. It’s easy to check: to do this, weigh the canister. A full container of 750 ml weighs about 900 g.
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The technology for installing modern metal-plastic structures: windows, doors, glazing of balconies and loggias, involves the use of polyurethane foam. Foam for installing windows is a reliable sealing material that has proven itself in the Russian climate, especially in conditions negative temperatures, where it demonstrates its high thermal insulation qualities.
Key Features
Reliability of polyurethane foam parameters can be achieved if technological process when installing a plastic window and choosing the right material. The characteristics of the foam must correspond to the conditions in which it is intended to be used: humidity, temperature, time of year and subsequent finishing of window slopes.
Installation of plastic windows is not complete without the use of polyurethane foam.
This modern material appeared on the construction market not so long ago and gained its popularity along with metal-plastic structures, since according to the technology of their installation, it is impossible to do without polyurethane foam. The mixture has high adhesive properties, does not allow electric current to pass through, easily fills hard-to-reach voids, is not subject to rotting and has heat and sound insulation qualities.
Composition and scope of application
On modern market There are many already proven brands and unknown brands of polyurethane foam, but in essence, it is a one-component polyurethane foam sealant in aerosol packaging. The liquid prepolymer is displaced from the cylinder using a gas - propellant, which is under conditions of excess pressure.
After spraying the composition, its polymerization occurs - hardening under the influence of moisture from the air. As a result, a porous material similar to foam is formed, which can be used for slopes and processed with any as necessary: cut, putty or plaster.
Putty and other materials can be applied to the hardened foam. Decoration Materials This material is used for installation and repair window frames, door frames, window sill boards, other structures made of concrete, plastic, metal and wood. Polyurethane foam is used when installing windows and doors to seal seams and cracks.
When working with polyurethane foam, you do not need to have any special skills. It does not require application additional accessories and sources of electricity.
Properties
This material is characterized by:
- the volume of foam, which indicates the size of the cylinder;
- adhesion, that is, the force of adhesion to the surface;
- foaming, which means the transformation of the composition from a liquid state to foam;
- expansion, which tells how much the volume of the foam increases during the hardening process. This indicator is important if sealing of deep seams and joints is required;
- secondary expansion.
The coefficient of expansion of the foam is especially taken into account when working with deep gaps The secondary expansion indicator has a negative effect and can play a role cruel joke while ignoring this property of polyurethane foam. For example, when installing metal-plastic structures in the form of windows and doors, as a result of secondary expansion of the foam, additional pressure occurs on structural elements with their subsequent deformation. To prevent this, spacers must be installed during window installation.
Spacers prevent window deformation Foam cannot be used for installation purposes on icy, polyethylene, Teflon, silicone and oily surfaces.
Positive qualities of polyurethane foam:
- non-passage of electric current;
- multifunctionality of use - as insulation, sealant, adhesive and soundproofing composition;
- water-repellent properties;
- fire safety class B1;
- due to its ability to significantly increase in volume, the foam effectively fills the most inaccessible places: seams, cracks, recesses, quickly hardening;
- the applied composition does not rot and is not afraid of mold;
- has high thermal insulation qualities;
- can be used for fixing water supply and heating pipes, electrical wiring;
- used as a sealant with insulating properties when installing roofing materials;
- When installing windows, polyurethane foam, due to its high adhesive properties, ensures reliable fixation of window and door units without the use of nails and screws;
- Soundproofing qualities allow you to dampen noise from vibrations. When installing plastic windows, this property complements the quality of the design and enhances the effect of soundproof rubber seals installed in the window.
Polyurethane foam reliably fixes window or door designs Flaws:
- despite the fact that the material repels water from its surface, moisture can accumulate in its porous structure, which over time destroys the structure of the foam and reduces its performance properties;
- destroyed by direct solar radiation;
- the presence of strict requirements for the storage of cylinders - vertical position and ambient temperature from not lower than 5 and not higher than 25 degrees;
- After contact with human skin, it is very difficult to wipe off and only with the help of solvents, so it is important to use gloves when working with foam.
Varieties
If the composition of the material is from different manufacturers has minor differences, then depending on the design of the cylinder itself, the foam can be professional or household.
Professional
Professional or pistol foam is characterized by its use in conjunction with an applicator gun as a device for dosing the material. For this purpose, the cylinder design is equipped with a special working valve onto which the gun is placed.
In professional construction, foam is used with an applicator gun The use of a dosing device allows you to deliver material portionwise into cracks and recesses, control the amount of material and save its consumption. The device itself is ergonomically designed and allows you to operate with one hand using the trigger and handle. A long thin metal nozzle allows you to feed material into the recesses. In this case, the position of the bottom of the cylinder does not matter.
The applicator gun is a professional device, therefore it has high cost. It is purchased by builders and installers whose field of activity is directly related to its use.
The applicator gun allows you to use the cylinder in any position Modern cylinders are equipped with reusable valves. This ensures that the container is tightly closed and the contents are preserved until the next use without losing its quality or drying out. The mechanism for attaching the cylinder to the gun can also be different: the valve can be threaded and screwed onto the gun or fastened.
Household
For household use It doesn’t make sense to purchase a dispenser gun, since caring for it requires special aerosol solvents, which also cost money.
For one-time use, it is more advisable to use a container with a plastic tube For occasional home use, manufacturers offer household polyurethane foam. It is also called semi-professional or manual and is represented by only one cylinder without additional devices, except for a nozzle in the form of a plastic tube, which is put on the valve before starting work.
Classification by seasonality
Depending on the temperature requirements, polyurethane foam can be:
- summer;
- winter;
- all-season.
Summer foam is recommended to be used at temperatures from 5 to 35 degrees. Winter foam used at temperatures from 18 degrees below zero to 35 degrees plus. The presence of special additives and additives ensures the polymerization process under conditions of low atmospheric humidity. It is important to remember that the higher the air temperature, the greater the expansion coefficient of the foam and vice versa.
The expansion coefficient of foam depends on the air temperature The all-season option is rarely seen on the shelves of construction stores, since this material is relatively new and is not produced by all manufacturers. The composition is characterized by improved qualities compared to winter and summer option, has an increased expansion coefficient and high speed foaming at temperatures down to minus ten degrees.
Selection rules
The modern construction market offers a huge selection of these products, from famous manufacturers, and new companies. To do right choice, it is important to pay attention to the following points.
Taking the cylinder in your hands, check it for underfilling, comparing the actual weight with the declared volume. A 750 milliliter cylinder should weigh from 850 to 920 grams. If there is not enough foam in the cylinder, the internal pressure will drop low enough and some of the foam will remain inside.
When purchasing a foam canister, you need to pay attention to the expiration date. The percentage of secondary expansion, which occurs after a certain period of time - up to several days, is very important. It should not exceed the primary value by more than 20 percent, otherwise deformation of structures will occur due to additional load.
The foam should adhere well to the surface, not flow off it, and have low shrinkage and elasticity. You need to purchase a bottle with a fresh expiration date.
Rules of application
Observing simple rules during operation, you can ensure that the polyurethane foam when installing plastic windows will last for a long time and will retain its qualities.
Considering that polymerization occurs during humid environment, before work, you should moisten the surface with water. As a result, hardening will occur quickly and the expansion coefficient of the foam will increase.
When working in winter period it is necessary to clear the surface of ice and frost.
Before application, shake the container vigorously for 60 seconds. In winter, the cylinder should be at room temperature.
When spraying the contents, the container should be held with the bottom up to concentrate the composite in the valve area. This will prevent a drop in internal pressure and allow the entire foam to be used.
When spraying the composition, the container must be held upside down. When filling a seam, you need to start work from the bottom and move up with a uniform movement of the cylinder. In this case, the seam must be filled 50%. If it is very deep, then this can be done in several passes, and each previous layer should set well.
It will take approximately 8 hours for the foam to completely harden, this indicator is related to humidity environment and temperature.
After hardening, excess foam is cut off with a knife. When the foam has hardened, you can cut off its excess with a knife and carry out work to protect its surface from external influences, such as moisture and sun. The foam can be plastered, puttied or painted. When installing plastic windows, it is hidden under casing or flashings.
Common brands
- Moment-Montazh;
- Makroflex;
- Soudal.
“Moment installation” is the most common option produced for domestic and professional use. According to seasonality - usually all-season. It has high adhesive properties. Due to its dense and homogeneous structure, it is most often used when installing metal-plastic structures.
"Makroflex" is also often found in stores. Suitable for use on any surface. Has a low coefficient of secondary expansion. Divided according to seasonal use.
"Soudal" is not often found on sale, but this foam is worth looking for as it has excellent qualities. It is characterized by the absence of toxins and specific odor, good density and minor porosity. In addition to winter and summer foam, the manufacturer produces fire-resistant options.