The history of the appearance of polyurethane foam
Polyurethane foam in the form in which it is known now, it began to be widely used in the 80s of the last century. But polyurethane foam, one of the types of which is polyurethane foam, was invented much earlier, back in the 40s, by the Swiss Otto Bayer, who headed a laboratory at the Bayer chemical concern. By the way, Otto himself has no relation to Friedrich Bayer, one of the founders of the concern, he is simply a namesake.
One-component, one-and-a-half and two-component polyurethane foam
Polyurethane foam can be one-component or two-component. In one-component foam, a pre-mixed prepolymer and a propellant gas, also called propellant, are placed in a canister. When leaving the container, the prepolymer foams, begins to interact with the moisture contained in the air, and polymerizes. If there is a lack of moisture, polymerization will be difficult, and large voids may remain inside the foam mass.
One-and-a-half-component foam, often called two-component foam, is stored in a container consisting of two parts. In one part there is a prepolymer, almost the same as in one-component foam, and in the other there is a catalyst that accelerates the curing process. Products from different parts containers are mixed immediately before use. One-and-a-half-component foam has a higher density than one-component foam, lower secondary expansion and lower yield. But it hardens very quickly. This type of foam is used for quick fixation of window and door blocks in openings instead of mechanical fastening. One-and-a-half-component foam is used quite rarely, since it is more expensive, has a smaller output volume and must be applied within 15 minutes after activation, otherwise it will harden in the container. In the vast majority of cases, the use of one-component foam is more economically feasible.
Two-component foam is obtained directly during application by mixing two different components using special equipment. This technology is used to produce a lot of products: from mattresses and car seats to thermal insulation, shoe soles and wood substitutes.
Application area of polyurethane foam
Due to such properties of polyurethane foam as low air permeability, low thermal conductivity, ease of use, it has found its application for sealing gaps when installing windows and doors, sealing cracks, insulating openings for pipes and cables, insulating balconies and other building structures. Today, more than 2,000 areas of application of polyurethane foam are known, ranging from construction to art. It must be clearly understood that ordinary polyurethane foam is not recommended for waterproofing, since it absorbs moisture. In some cases, only special types of polyurethane foam can be used for waterproofing. In addition, polyurethane foam is destroyed by ultraviolet radiation, and therefore requires protection from sunlight.
The excellent adhesion of polyurethane foam to most surfaces has also found application in construction. Special products have appeared, such as adhesive foam based on polyurethane foam. They differ from conventional polyurethane foam in that they have relatively low primary and secondary expansion, but at the same time higher adhesive properties. Using these products, thermal insulation boards are glued to walls and used as a binder for building blocks, wood materials, plasterboard, and metal tiles.
Polyurethane foam output volume
Perhaps the first characteristic that end consumers pay attention to. This is really important: the more foam that comes out of the can, the more work you can do with it. And this is a direct saving of both time and money. What determines the volume of foam output?
First of all, it depends on the amount of active substance filled into the container. The weight of the cylinder can serve as a criterion for this. You can often find that identical-looking cylinders from different manufacturers with the same declared volume of foam output differ greatly in weight. All other things being equal, more foam should come out of a heavier container than from a lighter one.
However, the volume of output depends not only on the filling of the balloon. Finished foam from different manufacturers may have different characteristics, such as density. And it is not always possible to obtain a larger output volume from a heavier cylinder than from a lighter one. In the same way, the foam that gives more volume is not always the best in other characteristics. For example, it may have a lower density and, as a result, worse thermal insulation.
Often people who decide to independently check whether the volume of foam output corresponds to that declared by the manufacturer discover that the volume turned out to be less than expected, and rush to accuse the manufacturer of dishonesty. But often the reason lies not in the buyer’s body kit, but in the test conditions. The volume of foam output is indicated for normal conditions, which are considered to be a temperature of +23°C and a humidity of 50%. The maximum volume of foam yield can be obtained only in laboratory conditions, fully observing the testing technology used by the manufacturer. For example, in dry weather or frost, the volume of foam output may be one and a half or even two times less. As for comparisons of the output volume from different cylinders, they can only be correct if the tests of these samples are carried out under the same conditions, by one person from the same gun, and best of all simultaneously.
Primary expansion of polyurethane foam
Primary expansion is the increase in volume of liquid foam immediately after the foam exits the nozzle. The mechanism of this process is as follows. Gases and prepolymer are in a cylinder under a pressure of about six atmospheres. Before use, the container is shaken, the gases are mixed with the prepolymer and partially dissolved in it. When leaving the cylinder, the mixture experiences a sharp drop in pressure and the gas bubbles compressed inside rapidly expand, forming foam. The process is similar to how carbonated drinks froth when opening a sealed bottle. This is why it is important to thoroughly shake the container before use: if this is not done, the output will not be high-quality foam with the stated output volume.
Naturally, the amount of primary expansion very much depends on external conditions: air temperature, application method, worker qualifications.
Secondary expansion of polyurethane foam
Secondary expansion is an increase in foam volume after the end of primary expansion and before complete polymerization. It is indicated as a percentage. Secondary expansion of the foam occurs as a result of the interaction of the prepolymer with moisture. During this reaction, carbon dioxide is released, the structure is formed and the foam hardens. The amount of secondary expansion depends on the formulation used and may vary from manufacturer to manufacturer. different types foam varies from 15% to 60% for professional foam and from 200% to 300% for household foam. Secondary expansion is a very important indicator that directly affects the quality of most work performed with foam. Therefore, before starting to work with foam that is new to you, it is recommended to conduct an experiment to determine the degree of secondary expansion and take this parameter into account when working.
Expansion pressure of polyurethane foam
As the foam expands, it puts pressure on the structure. The strength of this pressure depends not only on the degree of secondary expansion, but also on other characteristics of the foam. Foams with a high degree of secondary expansion do not always have high pressure on the design. This can only be established experimentally and, of course, then take this parameter into account when working with a specific brand of foam. When switching to another foam, you need to keep in mind that its expansion pressure may be greater and it may deform the structure more.
Time for initial processing of polyurethane foam
This term refers to the time after which the foam hardens enough so that it can be subjected to mechanical processing: trimming off excess, preparing for painting or putty. Manufacturers indicate this parameter on the cylinder; as a rule, it is several tens of minutes. But it should be borne in mind that this period is indicated for ideal conditions. In reality, it is best to make a test cut before machining to ensure that the foam has hardened sufficiently.
Time for complete polymerization of polyurethane foam
The time of complete polymerization is the time during which all chemicals in the foam are completed and the foam acquires its final structure. The polymerization time depends on several parameters: the quality of the foam itself, the thickness of the seam, the amount of available moisture and temperature. The faster moisture penetrates the foam, the faster and better the polymerization process. That is why it is recommended that before applying the foam, moisten the surfaces on which it will be applied, and after application, moisten the already foamed seam again. However, excessive wetting should be avoided - the surface should be damp, but not wet. With temperature, everything is the same as in any chemical reaction - the warmer it is, the faster the reaction goes. Under normal conditions, the polymerization time of polyurethane foam is about 12 hours, but in frosty or dry weather, polymerization is much slower and can take several days. As for the thickness of the seam, numerous experiments from various manufacturers show that moisture can penetrate into the hardening foam to a depth of no more than 3 cm. To layers lying deeper than 3 cm from the edge, penetration of moisture is difficult, therefore the diameter of the foam roller applied in one pass is should not exceed 6 cm. If it is thicker, there is a big risk that the middle of the roller will not polymerize - a void will form there. Such a seal will have poorer sound and heat insulation and can easily collapse. That is why large openings need to be filled with foam in layers. The second layer can be applied no earlier than a crust has formed on the first. And it is imperative to moisten the surface on which the second layer will be applied.
“Shrinkage” of polyurethane foam
During the polymerization process, carbon dioxide formed in the foam, creating inside overpressure, gradually leaves the pores and is replaced by air. Depending on the speed at which these processes occur, the foam can shrink or expand. In world practice, it is believed that fluctuations in foam dimensions of ±10% are acceptable for installation plastic windows and doors.
Storage conditions and shelf life of polyurethane foam
Cylinders with polyurethane foam must be stored in a vertical position with the valve facing up at a temperature from +5°C to +25°C. Only under these conditions does the manufacturer guarantee that the foam will retain its qualities throughout the entire shelf life indicated on the packaging. The temperature limits at which the foam must be stored may not be the same as the limits at which it can be applied. So, for example, you can work with winter foam at a cylinder temperature down to -10°C, but if you store it in the cold, it will become unusable much earlier than the period indicated on the cylinder. Freezing of the foam is allowed, but after this, to preserve the performance characteristics of the foam, it is necessary to correct defrosting cylinders. They need to be defrosted slowly, avoiding sudden heating.
Conditions for applying polyurethane foam
Different types of polyurethane foam may have different application conditions; they are usually indicated on the container. For summer species foam, the air temperature usually ranges from +5°C to +35°C; the highest quality winter ones, for example, KUDO ARKTIKA NORD, can be used at air temperatures down to -25°C.
It is necessary to distinguish between the outside air temperature at which the application of polyurethane foam is allowed and the temperature of the cylinder itself. For example, KUDO ARKTIKA winter foam can be used at temperatures from -18°C to +35°C, and the temperature of the cylinder should not be lower than -10°C. This is considered a very good indicator, since KUDO foams use AFC (Advanced Freeze Control) technology, which allows work to be done with a cooled cylinder. For foam that does not have such technologies, the permissible temperature of the cylinder is usually above 0°C. If the cylinder has cooled below the critical temperature, it must be warmed up by placing it in warm water for some time. Under no circumstances should the cylinder be heated with an open flame or a hair dryer - overheating may cause the cylinder to explode. Another important nuance– there should not be too much of a difference between the temperature of the foam and the temperature of the outside air, otherwise after application the foam may simply flow in the opening. For selection optimal temperature KUDO foam, you can use a special table.
No less an important condition For proper application of polyurethane foam there is sufficient humidity, usually it should be at least 50%. The foam polymerizes when it reacts with moisture, so to obtain a high-quality seam, it is recommended to always moisten the surface on which the foam will be applied before starting work, and after application, moisten the foamed seam again. If the foam is applied in several layers, each layer should be moistened.
Fire-resistant polyurethane foam
Fire-resistant polyurethane foam is used in places with increased requirements for fire safety. As a rule, fire-resistant foam is pink or red in color, occasionally gray. Thanks to this, it is easy to check which foam is used in the design - fire-resistant or regular.
It is important to distinguish between fire resistance and flammability. Flammability is understood as the ability of a material to maintain combustion, and fire resistance is the ability of a material to maintain integrity (E) and heat-insulating properties (I). Fire resistance tests are carried out for joints with a depth of 100 and 200 mm and a thickness of 10 to 40 mm. The time is measured in minutes during which the material was able to maintain its integrity and thermal insulation ability when exposed to an open flame.
Fire resistance indicators of KUDO polyurethane foam
When studying the fire resistance indicators of various brands of foam, it should be borne in mind that tests can be carried out for different types of joints: homogeneous from foam and combined from foam and basalt wool. If tests are carried out for a combined seam, this must be indicated in the characteristics. Such seams almost always have higher fire resistance ratings, but this does not mean that the foam itself has a higher fire resistance. It is correct to compare only indicators for seams of the same type.
Rules for working with polyurethane foam
Since polyurethane foam sticks very well to your hands and is very difficult to remove from them, you should always use protective gloves when working with it.
Before use, the container must be shaken so that the components in it are well mixed. If this is not done, you will not be able to obtain high-quality foam at the output.
Since foam polymerizes in the presence of moisture, the surface to be treated must be moistened before applying the foam. At sub-zero temperatures, moisture can freeze on the surface. Therefore, small areas of the surface should be moistened and foamed immediately, preventing the moisture from freezing.
When applying foam, you should definitely take into account the amount of its secondary expansion and try to apply the foam so that after polymerization there is no need to trim it. The fact is that a fairly dense film is formed on the surface of the foam, which reduces the hygroscopicity of the foam. If you cut it, the foam's ability to absorb moisture will increase.
After applying the foam, the seam should be moistened again for faster and better polymerization.
Polyurethane foam is destroyed under the influence of ultraviolet radiation, so after curing, the seam must be protected with plaster or another method.
During the installation of windows in the autumn-winter period, as well as in early spring, it is recommended to use winter foam. These polyurethane foams have high adhesive strength and good adhesion to a number of typical materials used in construction, reports the OKNA MEDIA portal.
Freezing temperatures do not necessarily mean it is necessary to stop construction or renovation work until spring. The use of appropriate winter foam allows work to continue, and the use of a heat shield protects the room from the harmful effects of frosty wind, snow, rain and low temperatures.
Winter polyurethane foam to the rescue
When in winter time We systematically observe that window slopes water vapor, water or ice particles are collecting, this is a sign that your window is leaking cold air inside, and the heated one releases outside. This situation is the result of improperly installed or insufficiently sealed windows, which leads to additional heat loss (about 10%).
Modern technologies make it possible not to postpone window replacement until spring, but to carry it out even in winter. One of these useful solutions is winter polyurethane foam. This type of mounting foam will allow you to work in harsh winter conditions (when temperatures reach up to -10 ° C). Already from +5 °C you should use winter foam for installing windows.
When installing windows in winter, you should pay attention Special attention on the type of foam that is used for this type of work. Using appropriate winter foam helps minimize uncontrolled air flow and helps keep your home warm.
What you should know about winter foam when installing windows yourself
Often, contrary to our expectations and plans, construction work is extended. Installing and sealing windows and doors should not be put off for a long time. In this way, it will be possible to prevent possible losses from atmospheric factors (snow drifts, access to moisture and frost).
If you decide to replace a window and you have some experience construction work– there is no need to involve a team of installers – you can install it yourself, which significantly reduces the cost of investment. When replacing windows in the cold season, winter foam should be used during the installation process. The best solution there will be low expansion foams. With their help, there is no risk of an uncontrolled increase in the volume of foam, and thus the risk of deformation of the window profile is prevented.
Before applying winter foam, it is necessary to clean the working surfaces from dust and dirt. To ensure better adhesion of the mounting foam, it is recommended to coat the surface of the base of the window opening with a deep penetration primer.
Do not forget to thoroughly shake the container for about 30 seconds before use - this will allow maximum use of the contents of the container. When applying winter foam, you should carefully fill all the gaps between the window and window opening, and remove the excess.
A problem in a private home may be the installation of hard-to-reach windows (for example, those located close to the ceiling). Most commercially available foams require the container to be positioned upside down. Therefore, when choosing a product, you should pay attention to multi-position foam, which can be used in any working position.
Winter window installation in capable hands
If you do not have experience in installing windows, you should not take risks using gun foam - it is better to use household foam or call a team of professional installers. While household foam can be used by anyone, winter spray foam is intended for professional window installers.
Gun foams are more difficult to use than household foams, so appropriate skills are required to work with them. A professional team of installers working in frosty winter conditions will use winter foam because its advantages are: resistance to low temperatures and high performance.
The use of these mounting foams is a guarantee of efficiency and high quality winter installation windows Additional feature winter polyurethane foams is the fact that they do not require the container to be adapted to room temperature, which means that they can be used on outdoors and indoors.
In addition, the team of professionals has a heat shield at its disposal, which makes installation more comfortable and does not cool the room too much.
The influence of low temperatures on the performance of polyurethane foam
When using polyurethane foam, it should be borne in mind that the lower the air temperature, the longer the time after which pre-treatment of the hardened foam can begin. The temperature factor affects not only the curing time, but also the performance of the product. The lower the temperature, the lower the foam yield. Winter varieties foams should solve this problem - they provide the ability to work at temperatures of -10°C.
In winter, it is advisable to use high-performance foams, since it is impossible to accurately calculate the effect of moisture and cold on the amount of foam and the time for its processing. It is better to allow for a certain degree of excess foam consumption than to face a shortage during the installation process.
Especially at low temperatures, experts recommend leaving the applied layer of foam until it hardens completely. Failure to comply with the recommended pre-treatment time can lead to irreversible changes in the structure and dimensional stability, and impair the useful qualities of the polyurethane foam.
It should be noted that during work carried out in the morning or late evening in early spring or late autumn, the temperature drops significantly, so the use of winter polyurethane foam is mandatory.
WINDOWS MEDIA recommends reading: At what stage of construction should windows be installed?
Summer foam for winter window installation is a big risk
At ambient temperatures below +5 °C, standard summer foams are not suitable for winter installation of windows. When using this mounting foam in winter conditions, there is a risk that the sealing layer will not harden properly, and the contents of the container may not form properly during use, that is, they may not reach the desired consistency.
What does this mean in practice? Doors and windows installed with summer foam at temperatures below +5 ° C will not be sufficiently airtight and will have to be replaced for some time. And replacing polyurethane foam is not so easy (the foam adheres tightly to the surface of window and door frames, so it is very difficult to remove). Summer polyurethane foam used during winter window installation quickly loses its properties. During the expansion process, it is more difficult to control such foam, which can lead to its “overdose”, and in practice this means that it will not insulate translucent enclosing structures well.
Winter polyurethane foams mainly differ from summer foams, first of all, chemical composition gas used as a foam carrier. This makes the product suitable for use at ambient and substrate temperatures down to -10 °C (in the case of professional gun foam -10 °C is sufficient, and for household foam - 8 °C).
Winter polyurethane foams have the same adhesion strength and ability to insulate as summer foams. At the same time, winter foams work well at positive temperatures and can be used in summer, but this pattern does not work the other way around (that is, summer foams cannot be used in winter). If after installing your windows you have unused winter foam, you won’t have to wait until next winter to use it.
Windows and doors are not all the possibilities of winter polyurethane foam
During frosts, the problem of heat loss is not only leaky windows or doors. Sometimes “gaps” form in walls and partitions made of concrete, brick, wood, metal and plasterboard. In winter, in these places, in addition to heat leakage to the outside, the likelihood of fungi and mold growing increases. Accordingly, it is required good seal these zones. For this type of work, you should also use winter mounting foams, which adhere perfectly to smooth surfaces, painted walls, glass or PVC. Some are also mold and mildew resistant.
With the onset of cold weather, water vapor, water or ice particles periodically collect on the window slopes, which are signs of improper installed windows, letting cold air in and heated air out, which leads to heat loss of up to 10%.
The solution to the problem may be installation window designs using winter polyurethane foam. Winter polyurethane foam has good adhesion and a wide temperature range, allowing you to continue working in harsh conditions (at temperatures down to -18 ° C).
5 rules when working with winter polyurethane foam:
1. Clean the surface from debris, dust and ice. In winter, at low temperatures, the moisture content in the air is significantly lower than in summer, therefore, to achieve best result it is necessary to moisten the surface with water from a spray bottle;
2. The foam container must be kept indoors for at least 12 hours or heated in warm water, bringing the container to room temperature;
3. Before use, be sure to shake the can for 30 seconds;
4. Winter foam, like summer foam, can be applied in several layers, with the second layer applied after polymerization of the first;
5. The applied foam must be protected from the weather - ultraviolet radiation and precipitation destroy the structure of the foam, increase its porosity, and make it brittle - ideally, have a heat shield that allows installation to be carried out more comfortably and does not cool down the room.
The main installation mistake using winter polyurethane foam is foaming the contents out of a cold and sometimes frozen cylinder. As a result of these actions, the yield and quality of the foam suffers.
To check how high-quality winter foam, such as Profflex , we decided to conduct an experiment to clearly demonstrate the results.
Stage 1- Preparation:
We froze four cylinders of high-quality winter foam from different manufacturers at a temperature of -18° C.
Stage 2- Foaming:
After 1 hour of freezing, the first foaming was carried out:
Result: the foam is slightly thick, the expansion is stronger than usual, the structure
After 2 hours of freezing, a second foaming was carried out:
Result: similar to the first.
After 2.5 hours of freezing, the third foaming was carried out:
Result: thicker foam, strong expansion, increased number of bubbles.
Conclusions:
Short-term cooling of high-quality polyurethane foam does not have a critical effect on its properties; such foam can be used without preheating. However, cooled foam can expand more under certain conditions, requiring less gap filling. In any case, the additional expansion of the foam is influenced by the ability of gases to dissolve in the liquid (in the prepolymer inside the cylinder), which, based on the laws of physics, is higher, the lower the temperature of the cylinder.
Therefore, before use, it is advisable to bring the container with polyurethane foam to room temperature. If you do not have such an opportunity, you should remember that long-term freezing is in any case unacceptable, short-term freezing does not lead to serious changes in properties, so transportation of polyurethane foam is possible over short distances, for example, in the trunk of a car. The specific properties of frozen or refrigerated foam will vary depending on freezing time and temperature. To avoid possible installation difficulties, we recommend warming up the foam before use.
Household polyurethane foams with an applicator tube: Foam Premium (Penosil) summer (750 ml pack - 262 RUR). Photo: Penosil
Polyurethane foam is an indispensable element of many construction works. It is used for doors, filling various openings and openings, for connecting and sealing structures, fixing wall panels and roofing slate. Among the main manufacturers of these products are Henkel ( trademark Makroflex), Bison International, Den Braven, Penosil, Profflex (Profflex, Storm Gun trademarks), Soudal, Selena (Tytan Professional trademark). The price of a cylinder with polyurethane foam depends on its volume, weight, popularity of the brand and ranges from 100 to 600 rubles. It is worth noting that polyurethane foams are divided into one- and two-component ones. Since most of the foams presented on our market are single-component, let’s talk about them.
The consequence of poor sealing is distortions, sagging, and reduced service life of windows. Correct use of foam provides the necessary heat and sound insulation. Photo: ShutterStock/Fotodom.ru
What is polyurethane foam?
Maxi (Profflex) all-season (pack 750 ml - 218 RUR). Photo: Profflex
One-component polyurethane foam is polyurethane sealant in aerosol packaging. The basis of the foam is a prepolymer (prepolymer) synthesized from a polyol and isocyanate. As a result of the polymerization reaction, partly occurring inside the cylinder, and mainly in the air, after release outside, these substances form polyurethane. Coming out of the container, the prepolymer sharply increases in volume (20–40 times) and turns into foam. Expanding, it penetrates into hard-to-reach cavities and fills voids. Then the cellular mass gradually polymerizes (hardens), absorbing moisture from the air or from a previously wetted surface. After a day, it becomes a chemically stable substance - polyurethane. It is non-toxic, does not deteriorate for a long time, and is resistant to moisture. This rather rigid, finely porous material consists of closed cells and serves as a good insulator.
How is household foam different from professional foam?
Tytan Professional STD (Selena) summer (750 ml pack - 315 RUR). Photo: Selena
The container with household foam is equipped with a special applicator tube. Thanks to this device, no additional tools are required to release the viscous mixture. Household foams are generally single-use products. The yield of the mass is difficult to dose, and it itself is characterized by high density and low polymerization rate. Professional foams are designed for repeated use and better sealing. In them, the supply and dosing of the foam jet occurs using a plunger gun. It is screwed onto a special ring on the cylinder. It is professional foam that should be given preference when installing doors and windows.
At what temperature can foam be used?
Soft foam cleaners: PU Foam Cleaner Click (Soudal) (500 ml pack - 257 RUR). Photo: Soudal
Depending on the operating temperature range, polyurethane foams are divided into summer, winter, and all-season. For the first range permissible temperatures is in the zone of positive values: from 5 to 30 ˚C. Winter and all-season foams are used in a wider range: from –10 °C (some from –25 °C) to 30 °C. In this case, it is worth considering the manufacturer’s advice on the temperature of the cylinder. In the cold season with low air humidity, the flow chemical reactions slows down, the viscosity of the mixture increases, and the pressure in the cells of the foam mass decreases. For normal operation, many manufacturers recommend warming the cylinder to room temperature (23 ° C), keeping it in a living room for about a day or immersing it in warm water(about 30 °C). However, there are products for which the use of a cold cylinder is acceptable.
Winter foams contain components that help better absorb moisture from the environment and maintain the desired consistency at low temperatures. Winter foams can be used in cold and warm seasons without compromising their performance properties. Photo: ShutterStock/Fotodom.ru
Why do you need to shake a can of polyurethane foam before work?
ECO Tytan Professional (Selena) (500 ml pack - 235 RUR). Photo: Selena
A container of polyurethane foam contains several components of different densities. If stored immobile for a long time, they can become distributed in layers. Therefore, before starting the process, the container should be shaken vigorously for half a minute to mix the components. Also, shake it periodically during use and especially after smoking breaks. Insufficient shaking can lead to the formation of a coarse foam structure and reduced volume. During operation, the cylinder is held upside down. In this position, the propellant gas drops below the polymer mass and ensures maximum use of the contents.
The surfaces on which polyurethane foam is applied must be thoroughly dust-free and free of dirt, oils, grease and ice. Photo: ShutterStock/Fotodom.ru
How much foam is needed to fill cavities?
Cleaner for hard foam: Tytan Professional (Selena) (100 ml pack - 379 RUR). Photo: Selena
In order to prevent deformation of insufficiently strong walls during the expansion of the foam mass, it is recommended to fill no more than a third of the voids and cracks with foam. It is advisable to use several spacers to secure the box. Then the foam increasing in volume will not be able to deform it. However, with the correct professional dosage of foam, this is not necessary.
The volume of finished foam depends on the capacity of the cylinder and its filling, the temperature of the air and the cylinder, air humidity, the quality of the gun and the qualifications of the craftsman. High-performance foams produce 65 liters or more, while regular foams produce 25–45 liters.
Should surfaces be dampened before applying foam?
Relative Humidity more than 50% air is sufficient for the normal foam polymerization process. In such conditions there is no need to moisten the surfaces. However, with low humidity (less than 50%), which is typical during the cold season and hot summer days, moistening the seams and cavities will increase adhesion and improve the curing of the foam. This should be done without fanaticism, so that there are no drops on the surface and no water accumulates, otherwise its excess will prevent the foam from connecting to the surface.
Construction pistol it is necessary to clear the foam immediately after removing the empty cylinder, preventing the mass from hardening inside the gun. Photo: ShutterStock/Fotodom.ru
When can you cut off excess foam?
The polymerization time of polyurethane foam is affected by the temperature of the environment, the cylinder itself and the size of the cavity. On average, professional foam hardens in a cavity 30 mm wide in 20–30 minutes, while household foam hardens somewhat more slowly, in 40–60 minutes. The expansion process is completed in a day, and then you can begin to remove the solid mass.
Foam cleaners
Winter professional mounting foams: Makroflex Premium Mega 70 (Henkel) (870 ml pack - 390 RUR). Photo: Henkel
Polyurethane foam left after mechanical cleaning gun, cylinder (valve and the cylinder itself from the outside), clothing and other surfaces, can be easily removed using a special aerosol cleaner. There are two types of cleaners available:
- for soft foam;
- for hardened foam.
How to store and reuse a foam canister?
Soudafoam Maxi 70 (Soudal) (pack 870 ml - 336 RUR). Photo: Soudal
You can interrupt work with household polyurethane foam, the container of which is equipped with an applicator tube, only for a short time, no more than half an hour. The mixture dries quickly in air and can block the exit of the remaining foam. When using professional foam, manufacturers recommend not removing the gun from the cylinder until all the contents are empty. During storage, the trigger mechanism of the pistol is blocked with a metering screw.
In this condition, the cylinder with the gun can be kept for 1–2 weeks. But its prolonged exposure to warm and humid conditions significantly reduces the shelf life of polyurethane foam. But a dry and cool room is ideal for storing the cylinder. Moreover, they install it vertically, with the valve up, since a horizontal position leads to valve malfunction.
Does foam need to be protected from sunlight?
Tytan Professional ICE 65 (Selena) (870 ml pack - 340 RUR). Photo: Selena
Polyurethane foams are very sensitive to UV rays. The hardened mass darkens and crumbles under the influence of sunlight. The foam must be protected from light by plaster, panels, etc. In addition, the frozen mass does not tolerate temperatures above 110 ° C, exposure to alkalis, acids and compounds used to remove foam residues.
Adhesive foam
GoldGun 65 (Penosil) (875 ml pack - 345 RUR). Photo: Penosil
The scope of application of polyurethane foam is expanding. Many manufacturers, including TECHNONICOL Corporation, Henkel, Selena, offer adhesive foams for fixing thermal insulation boards made of polystyrene foam, extruded and pressed polystyrene foam, when installing systems on surfaces made of concrete, brick, plastered, etc. In addition, adhesive foams used in the construction of walls and partitions from. Unlike conventional foams, adhesive foams have higher adhesion and a low degree of expansion.
Professional mounting foams: all-season Construction 70 (Penosil), application temperature from –10 to 30˚С (pack of 870 ml - 336 rubles). Photo: Penosil
Summer Soudafoam Professional 60 (Soudal) (750 ml pack - 390 RUR). Photo: Soudal
Summer Tytan Professional Gun (Selena) (750 ml pack - 343 RUR). Photo: Selena
Last winter, I became concerned with the question of how to correctly, i.e., according to technology, use polyurethane foam at sub-zero temperatures.
Since I was not an expert in these matters, and the foremen also did not give clear and comprehensive answers, I wrote official letters to companies that sell polyurethane foam under well-known brands: Putech, TYTAN, SOUDAL, Tremco-ILLBRUCK.
The text of the letters was as follows:
Good afternoon, ………………………………………………………
We ask you to clarify some features of the use of products…………………winter foam (winter one-component polyurethane foam).
Questions:
1) foam exit
2) its expansion
3) polymerization
4) thickness of the applied layer
5) performance qualities and characteristics.
3. Is it possible to apply foam in several layers at sub-zero temperatures, in particular at temperatures below -10 degrees? How long should the time interval be between subsequent application of layers? The characteristics of this “pie” worsen (improve).
4.2. If possible, then for what period of time in winter and summer.
4.3. Is it possible to leave uncut foam when it snows or rains? How hygroscopic is the foam under these unfavorable conditions?
4.4. At what humidity can your product be used and for what period of time?
Sincerely, ………………………………….
Leading designer of the department……………………………………..
OOO "…………………………………………….…"
Russia, Saint-Petersburg
mob. tel.:…………………………………………..
tel.: ………………………………………………………………..
Fax: ……………………………………………..
A few days later, answers were received - recommendations from official dealers:
from the official dealer “SOUDAL”:
Good afternoon,
Attached I am sending you a technical sheet with an exact description. technical properties our foam. Below are the answers to all your questions point by point.
- “Arctic” polyurethane foam can be used in temperatures from -25C to +25C.
1). At 200C - 65l., 00C-40l., -100C -35l., -250C - 30l.
2). Does not affect expansion
3). 200С - 1.5 hours, 00С - 3-5 hours, -100С - 8-10 hours, -250С - 10-12 hours.
4). Thick up to 5cm. But for more accurate information, I suggest contacting the window manufacturer since we sell foam for sealing windows, and each window manufacturer, depending on the profiles used, may have different recommended parameters.
2. Cylinders can and should be heated in hot water to min. 50C.
3. You can apply the foam in several layers at sub-zero temperatures down to -250C. The duration depends on surface polymerization; once it has appeared, a new layer can be applied.
4. Closing the foam is mandatory since it is adversely affected by ultraviolet radiation and other atmospheric factors. In principle, the foam can remain outside without closing for 2 days (this is how the situation looks in practice), but we recommend it immediately. Ultraviolet radiation and other atmospheric factors disrupt the structure of the foam, worsening the sealing of seams.
4.4. The best air humidity for working with our polyurethane foam is up to 60%. Air humidity is the main factor in the polymerization of polyurethane foam. The higher the humidity (up to 60%), the faster the polymerization. For this reason, installers spray the seam with water before and after applying foam (in summer).
Sincerely
Glovatsky Vladimir………………………….
Sales Coordinator
from the official Putech dealer:
Hello ……………………………………………….!
You wrote to us!
I tried to answer your questions.
1. Is it possible to use Putech PRO brand polyurethane foam at temperatures below -10 degrees? If possible, to what temperatures and how does it affect negative temperature on the:
1) foam exit
2) its expansion
3) polymerization
4) thickness of the applied layer
5) performance qualities and characteristics.
The use of polyurethane foam below -10 degrees entails a sharp loss of the quality of the polyurethane foam. Therefore, use the instructions written on the cylinder! It is undesirable to use polyurethane foam below: -10-12 degrees. When using MP above -12 degrees, and even more so even lower, “crumbling” of the MP is possible!
2. Is it possible to heat a cylinder (if possible, to what heating temperature and to what external temperature of use) with polyurethane foam near a heat gun, battery, fan heater (heating device), and then use it to seal assembly joints
Heating the cylinder is not even possible but desirable!!! This will dramatically improve the quality of the applied foam with active mixing (at least 1 minute).
I want to warn you - using polyurethane foam near a heat gun is PROHIBITED! MP contains flammable materials! Everything related to open fire is prohibited when using MP (propane-butane mixture - propellant gas)!
You can heat the cylinder up to a maximum of +50 degrees...for example, in a bucket of hot water! Immediately before use.
3. Is it possible to apply foam in several layers at sub-zero temperatures, in particular at temperatures below -10 degrees? How long should the time interval be between subsequent application of layers? The characteristics of this “pie” worsen (improve).
It all depends on the external conditions when using MP. It is advisable to wait between layers for 5 to 15 minutes (higher foam yield). For the formation of a stable surface film. But you don’t have to withstand it - which will entail greater consumption of foam and an improvement in the structure in terms of density..
4. How mandatory should it be to cover the foam inside and outside the room, when used in winter and summer.
4.1 Is it possible to leave untreated foam uncovered at negative (at positive) temperatures.
4.2 If possible, for what period of time in winter and summer.
4.3 Is it possible to leave uncut foam when it snows or rains? How hygroscopic is the foam under these unfavorable conditions?
4.4 At what humidity can your product be used and for what period of time.
It is necessary to close the foam! MP is afraid of ultraviolet radiation ( sunlight) - its “decomposition” occurs; it can be covered with plaster, paint, etc. Where the sunlight doesn't reach - long time you don't have to close it.
During work at sub-zero temperatures, it is advisable to temporarily cover the outside of the assembly seams (preferably). During installation, monitor the condition of the surface of the work seam! Snow, ice, dust and other foreign objects should not accumulate there. It is important! The period of time of an unclosed seam is possible for a long time (subject to the application conditions).
Snow and rain do not negatively affect the finished (frozen!) polyurethane foam.
Humidity has a positive effect on MP. Since polymerization occurs under the influence of moisture in the air! Therefore, it is advisable (if possible) to spray the working seam with water before using MP! No more than 50 ml per MP cylinder!
With respect and hope for mutually beneficial cooperation Ivin Victor………………….
from the official dealer “Tremco-ILLbruck”:
POLYURETHANE PROFESSIONAL WINTER FOAM
illbruck 1K Pistolenschaum. Polyurethane foam, winter
placed on the cylinder and are useful in work, such as when sealing window
assembly seams, and during other construction work.
Dear Sirs,
Illbrook Corporation produces quality insulation materials and develops sealing systems and technologies for their application.
The main goal of such developments is the quality of the final product and ease of installation.
In the Eastern European market, the corporation pays great attention to the use of its products in winter conditions. An example is high adhesiveness
mounting strips of insulating and self-expanding sealing tapes.
A lot of work was also done by the specialists of the company ILBROOK
to develop a special formula for winter polyurethane foam, which in the past season had virtually no analogues in terms of manufacturability and the final result obtained.
The specificity of working with polyurethane foam during cold periods of the year is that work can be performed both outdoors at sub-zero ambient temperatures and sealed surfaces, and at positive temperatures. In practice, for example, when replacing windows in used premises, foam is applied to the installation gap, the surfaces of which have a minus temperature outside the joint and a plus temperature inside. In this case, the installation seam is filled, as a rule, from one cylinder. When working, this situation should be taken into account and foam should be applied to the joint in two steps. ILLBROOK 1 – K polyurethane foam “works” equally stably on cold surfaces at a temperature of the components inside the cylinder within +6 - +14 degrees. WITH.
The adhesion of fresh foam decreases at a temperature of the contents of the cylinder of +20 C or more degrees to the cold surface, and at a low temperature of the contents of the cylinder -
to a warm surface.
To obtain higher stable results, two main points should be ensured: do not allow the temperature of the contents of the cylinder to drop below +10 degrees. During operation, shake the container vigorously periodically (after each stop).
Polyurethane winter polyurethane foam Illbrook has a number of features:
emits well from the cylinder at an ambient temperature of 10 degrees C and below;
primary polymerization occurs faster than analogues, bypassing the threshold of fragility when the layer freezes;
the primary expansion of the foam is 75 - 80%, which is especially appreciated by installers, because significant secondary expansion creates additional pressure on window unit, window sills and other installation elements;
the foam has good adhesion to cold surfaces that are free of dirt, ice and frost, and does not drain from vertical seams;
You should not artificially increase the temperature of the cylinder, since the material foams well in the cold, gives a dense structure and shrinks slightly with the subsequent rise of the layer;
Letter part 1_2.
for users of polyurethane foam (ILLBROOK – 1K)
These recommendations are intended for the use of PU foam in emergency situations. These may include violations of the conditions of storage, transportation, work in extremely low and high temperatures(below minus 10 degrees C and above + 35 degrees C).
External signs of abnormal condition of the contents of the cylinder are checked by lightly shaking the cylinder up and down. The absence of mass movement inside the cylinder or movement inside a thick homogeneous mass means that the components are cooled below the permissible limit + 10 degrees C or the cylinder has been in a horizontal position for a long time.
In this case, the cylinder should be heated at a temperature not lower than + 20 degrees. C and not higher than + 45 gr. C according to the “temperature – time” scheme, until active bursts appear inside. That is, the warm-up time depends on the temperature of the environment, and if the cylinder is clearly frozen, the temperature rise should be smooth, and the warm-up duration should be at least one day.
Working with PU foam has some features that increase the yield and quality of the final product. It is better to shake the container in the working position, bottom up, until a homogeneous mass bursts (this ensures a more uniform mass release, without individual bubbles).
Then screw the gun on and keep it ready for work, in the working position, for about one minute (this is necessary to move the gas component upward, which acts as a supercharger). Next, loosen the trigger adjusting nut by about half the thread stroke and start working.
If, when you press the trigger, gas comes out or the mass does not foam, repeat the shaking and holding operation (this will increase the volume of finished material).
During operation, the cylinder should be shaken periodically 3-4 times if the work is continuous, and always after long stops, while the trigger adjusting nut is screwed in immediately after stopping (this prevents air from entering the inside of the gun).
The temperature of the cylinder should be maintained within +10 degrees. WITH.
If the foam layer is frozen, fragile and collapses when pressed with a finger, or the next work operation needs to be continued, then it should be warmed up with a stream of warm air with a temperature not exceeding 100 degrees. With (for example, a conventional or industrial hair dryer), until the layer hardens.
In order to prevent the foam from freezing, it is advisable to warm up the joint simultaneously with filling it, in which case the joint cavity may be moistened.
If work is being done to seal a joint that is closed in 3 planes and closed after the foaming process on the 4th side (for example, with a vapor barrier layer), then heating and other things are not required, because the foam layer will become dense and elastic, providing everything technical qualities seal and thermal insulation material after 24 hours or when the ambient temperature rises close to 0 degrees. C and above.
If the cylinder overheats (this is felt when shaking the very liquid state of the components), as well as when working in an environment with a temperature above +30 degrees C, the cylinder should be cooled to a temperature
25 degrees C, control humidity, moisten the joint if necessary.
Failure to comply with these conditions will result in the appearance of large pores, uneven swelling and loss of elasticity of the layer.
Illbruck 1K NBS, Illbruck 1K Winter, Illbruck PRO 70
When transporting polyurethane foam in various types transport, the following recommendations should be observed:
Provide temperature regime environment within
from – 20 degrees C * to +25 degrees. C**, when transported in open transport - protect from the wind;
(*transportation at a temperature of –20 degrees C is allowed for short-term
(within 7-8 days), followed by slow (about 2 days) defrosting in a stepwise temperature transition from 0 – +5 to +20-25 degrees C, until the contents of the cylinder freely splash.
** transportation and storage of foam at an ambient temperature of +40 – +45 degrees. C explosive)
Transportation and long-term (more 3 days) storage in conditions high humidity Not recommended:
Foam should be transported in a vertical position (flap up), preferably in manufacturer's boxes:
When loading and unloading, throwing boxes of foam and individual cylinders is not allowed:
Laying boxes with foam in vehicle no more than 3 rows in height are allowed:
A separate stack should be secured to prevent the boxes from falling apart during transportation;
Transportation and installation (during storage) of pallets with foam boxes in two or more rows in height is not allowed.
Sincerely, Product Manager
Tremco-Illbruck
Shmelev Vladimir Alekseevich
t. 812 922-24-51
t. 812 324-40-94
from the manufacturing company “Selena” polyurethane foam “TYTAN”:
(My request was forwarded to Poland. The answer was from a Polish specialist, whose native language is Polish. Therefore, the grammar in the answers is a little “lame.”
Good afternoon.
We ask you to clarify some features of the use of the product TYTAN O2 1965
(winter professional polyurethane foam).
Questions:
1. Is it possible to use polyurethane foam at temperatures below -10 degrees? If possible, to what temperatures and how does negative temperature affect:
2. Is it possible to heat a cylinder (if possible, then to what heating temperature and to what external temperature of use) with polyurethane foam near a heat gun, battery, fan heater (heating device), and then use it to seal assembly joints.
The most good conditions, - room temperature at the cylinder and pistol.
Cannot be higher than +30 0C (indicated on the label). For safety reasons, you should warm the cylinder in warm water.
3. Is it possible to apply foam in several layers at sub-zero temperatures, in particular at temperatures below -10 degrees? How long should the time interval be between subsequent application of layers? The characteristics of this “pie” worsen (improve).
Yes. Each subsequent layer must be applied as the previous one dries. Drying time = see above (depends on temperature).
4. How mandatory should it be to cover the foam inside and outside the room, when used in winter and summer.
Always after application it is necessary to protect the foam from UV rays using sealant, plaster or paint (not before it dries).
The sun affects the structure of the foam (polyurethane) and it disintegrates.
4.1 Is it possible to leave untreated foam uncovered at negative (at positive) temperatures.
see above
4.2 If possible, for what period of time in winter and summer.
4.3 Is it possible to leave uncut foam when it snows or rains? How hygroscopic is the foam under these unfavorable conditions?
Once it dries, its water absorption is 1.5% and its heat resistance (after hardening) is from -60 0C to +100 0C
4.4 At what humidity can your product be used and for what period of time.
the duration is not limited - once it dries it does not allow moisture to pass through
SELENA FM S.A.
ul. Strzegomska 2-4, 53-611 Wroclaw, Poland
mobile: +48 600 45 51 54; phone: +48 71 7838 276; fax: +48 71 7838 291; skype: selena_pl_tszczot
www.selena.pl!}
This technical information was useful to me both that winter and this one. I want, realizing that a year has already passed, to express my gratitude to the specialists who responded to my request.
