How long does the polyurethane foam dry? Curing time of polyurethane foam

In fact, the question "How long does the polyurethane foam dry?" delivered completely wrong! The secret to transforming the prepolymer into strong polyurethane foam is how well it gets wet. The speed of foam "drying" depends on moisture. Let's figure it out in more detail.

Expansion coefficient is the main parameter

The value of this building material mostly depends on its ability to expand many times over. Household foam is capable of expanding up to 60% of the initial volume, professional formulations have a much higher coefficient - up to 300%. Moreover, the same foam in different conditions can expand in completely different ways. The prepolymer is influenced by temperature, air humidity, type of application, and the rate at which foam comes out of the can. And different masters in the same room may have different results. On the packaging, manufacturers indicate the maximum volume of polymer yield, but one should not focus strictly on it.

Expansion of the prepolymer during the exit from the balloon and solidification is divided into two types: primary and secondary. Primary expansion is called expansion immediately after leaving the balloon, secondary lasts until the completion of the polymer transformation process. The secondary expansion of high-quality materials reaches 30%, which cannot be ignored when using them. Usually it is enough to fill the gap by one third, so that in the end it is completely filled with polyurethane foam.

In addition to expansion, polyurethane foam can shrink, although for high-quality products, this shrinkage is rarely 5%. If you see a lot of shrinkage - alas, you came across a very low quality polyurethane. In this case, even a mass gap may occur, which in turn will entail a host of other problems. Each master selects the foam according to his needs. Someone needs a large extension, in such cases it will do Makroflex, Penosil GoldGun, Moment, Macrosilwhen installing windows it is best to use Tytan - it gives optimum expansion and hardens quickly.

The characteristics of the polyurethane foam - let's figure it out in detail!

This sealant began to be used in the construction industry relatively recently, but during this short time, polyurethane foam has almost completely replaced its former competitors. It is easy to apply, is inexpensive, lasts for many decades, and has sound and heat insulating properties. Most often it is used to seal the gaps between the doorway and the door frame during its installation, as well as when installing windows.

Expanding, the sealant fills all the voids, reliably "glues" surfaces to each other, and when solidified, the polymer fixes the door frame or window. Foam is not afraid of precipitation and cold, it does not let in electricity and is not afraid of mold and mildew. The only drawback is the fear of ultraviolet radiation, however, the material is often applied at the stage of rough work, which are then hidden under a decorative layer of plaster.

Anyone who comes across this material quite often begins to pay attention to parameters such as:

• Porosity of polyurethane foam. The smaller the pores, the better - less plaster consumption and stronger material structure. The more closed pores on the surface, the better the material there - it reliably retains heat inside the house.
• The volume of polyurethane foam. This refers to the volume of the polymer after it has solidified. It is important to remember that manufacturers indicate the volume based on standard climatic conditions: positive temperature, high humidity. In winter, the volume of ready-made foam from a cylinder of the same company can be half as much, and the company has nothing to do with it - the low temperature and low air humidity are to blame. than from the option with a ready-made adapter, since manufacturers pump more gas into professional cylinders. It is a fact that in household cylinders very often the gas runs out earlier than the material, and this is a waste of money. Traditionally, cylinders have a capacity of 300 ml, 500 ml and 750 ml. 300 ml can contains about 30 liters of foam, this is enough to close up a gap of up to 5 cm between one door frame and a doorway. If the gap is larger, it is recommended, in order to save money, to reduce the width of the gap by using a layer of foam or other similar material. The foam output from a 500 ml container is up to 40 liters, and from a 750 ml container - up to 50 liters. One 750 ml can is enough to process two standard door frames.
• Material adhesion. The very concept of "adhesion" means the ability of one material to stick to another. In the case of polyurethane foam, the adhesion of the material is very high to almost any surface, except cellophane, polyethylene and Teflon. Due to its high adhesion rates, this sealant is often used as an adhesive, especially when gluing PVC or foam panels. Be sure that after the binder has completely hardened, the panels can only be peeled off with the "meat". High adhesion allows you to close even large gaps by applying the polymer in several layers. However, in such cases, do not save on material - poor quality foam clings to the surface worse, falls down, more is consumed. In short, it is cheaper to buy the more expensive cylinder.
• The quality of the balloon. Both the design and the quality of the cylinder can affect the final result. Firstly, quality products are equipped with reliable valves that easily return to their original position after pressing, blocking the air and gas outlet. By the way, it is by the cylinders that you can determine what you are dealing with - a high-quality material or a cheap fake. Take two cylinders for comparison in a store for comparison - if the contents are different in quality, then you will feel it. The best bottle will be heavier, as you move, you will feel the contents roll slowly from side to side. In a cheap bottle, the prepolymer will dangle like sour yogurt.

How much polyurethane foam dries - we are looking for the exact answer

As you already understood, polyurethane foam is a rather complicated material and has many nuances. As in the case of the expansion coefficient, which depends on many factors, it is rather difficult to answer the question "How long does the polyurethane foam cure?" First of all, it depends on the humidity.

Water participates in the process of polymerization of the prepolymer, moreover, the foam has increased adhesion to wet surfaces, which is why it is recommended to wet the crevices and openings with water before applying the foam.

If the humidity is normal, then 3 hours will be enough for a five-centimeter layer to harden, after which you can cut off the protruding pieces of polyurethane foam and apply plaster. The final cure will take much longer - 7 to 12 hours. If the weather is frosty and dry, then the process can drag on for a day. It is this time that will be the final answer to the question "How long does the polyurethane foam dry?" In any case, if time permits, take your time, wait until everything hardens properly.

To speed up the curing process, periodically spray or moisturize in any way convenient for you. Remember that polymers are afraid of the sun's rays, so as soon as the opportunity arises, paint or plaster the surface that is in contact with ultraviolet light. The plastering process is very similar to.

How long it will take to when it will be possible to use the doors after their installation depends on many factors, first of all - on the means used, which ensures sealing at the junction of the door frame with the wall. Also, the rate of polymer solidification is affected by the state of the environment: temperature and humidity. The quality of the sealant is determined by its coefficient of expansion and adhesion, characterized by the adhesion forces of the foam to the surface.

Expansion ratio

Polyurethane foam is prized for its ability to expand quickly. Household types of this sealant can increase in volume by 60% of the original state. Professional foam has a higher expansion coefficient and doubles or even triples its original appearance. The expansion coefficient can vary depending on the humidity and temperature of the environment in which the polymer is used, on the rate at which the agent is withdrawn from the container, and on the way the foam is applied to the surface.
The polymer belongs to a dielectric building material, it is not afraid of mold or mildew. The only damage to already hardened foam during operation can be ultraviolet radiation. If the sealant is used outdoors, it is recommended to cover it with finishing materials. Porosity is another important quality of the composition. The fewer the pores, the stronger the connection and the lower the consumption of the composition.
The volume of already frozen foam is also indicated on the cylinders. Manufacturers inform about these parameters taking into account the normal conditions for use: positive temperature conditions and high humidity conditions. Foam, even of the highest quality, can be cut in half in a cold atmosphere.

Adhesion

An important characteristic of the sealant is adhesion, which indicates the ability to adhere the composition to the surface. For a quality material, this unit of measurement should be high in relation to any building materials. Connection problems occur when you need to fix polyethylene or cellophane, or Teflon.

The quality of the joint material depends on the packaging. Good containers have durable and reliable valves that prevent the atmosphere from entering the cylinder and the excessive escape of compressed gas from it.
A good quality balloon has more weight and if you turn it over, you should feel how the contents move quietly and slowly in it.

How long does the polyurethane foam dry

A hermetic agent is a rather complex building material. Characteristics and quality are ambiguous and depend on a lot. The foam goes into a solidified state under the influence of its own data and the conditions of the environment in which it is used. The polymerization process depends to a large extent on water. The higher the humidity, the faster the agent solidifies and the degree of adhesion increases. Professionals recommend wetting the surfaces of cracks and openings with water before starting to seal them.

If the humidity is high, then a 5 cm layer of prepolymer will dry for about 3 hours. Then he gains the required hardness for another 6-9 hours. At negative temperatures, this process stretches to a day. Builders with experience do not recommend rushing with the final finishing of already foamed holes and cracks. The sealant must be given time for maximum solidification in order to gain strength: in the summer - a day, in the winter - one and a half days. In order for the material to harden faster, it must be periodically moistened. The main thing is to remember that the polymer does not tolerate solar radiation.

Sealant selection and market analysis

The use of high quality and reliable building materials is the key to a successful repair. To seal cracks, holes, seams at a professional level, a product must be selected with high operational and technical data.

In the construction markets, you can find a large amount of different polyurethane foam. Experts recommend paying attention to the following product brands:

1. "Moment Montage"... A well-known brand with a well-deserved popularity, is sold in all building stores. Differs in density of homogeneous consistency, high adhesion to almost any materials. You can work with it both indoors and outdoors. Minus - secondary overgrowth, as a result of which, with a large amount of foam, the sealed joints can deform.
2. "Makroflex"... One of the best brands. Can be used for work both in winter and in summer. The foam has a uniform structure, adheres perfectly to any surfaces, and secondary growth is minimal. The disadvantages include a market defect in cylinders that do not work for long. Then either only gas or just a sealant comes out of them.
3. "Soudal"... Not a very well-known company that produces quality products. There are polymer options on the market for winter and summer work. Winter species are suitable even in 20-degree frosts. All products have good adhesion, little secondary growth, little shrinkage. Foam also does not react well to the sun.
4. "Penosil"... High-quality hermetic product of dense consistency. Secondary expansion is almost absent, it has a large outlet size. Effective for indoor use, not suitable for outdoor use. Temperatures below minus 4 and above plus 35 completely discredit him.
5. "Titan 02"... The most famous brand of professional polyurethane foam. It has a relatively low cost, it has excellent performance properties, a high degree of adhesion, and a dense consistency. Suitable for use in various conditions.

Conclusion

There is no perfect sealant. Every professional knows that any material is characterized by both positive and negative properties. In order for the result of the work performed to be desired, you need to carefully select the product and use it in accordance with the instructions from the manufacturer.

No construction site can do without polyurethane foam. This amazing material adheres to various surfaces, and also has good sound and heat insulation, the ability to seal hard-to-reach places. How much it dries Before you know the answer, you need to familiarize yourself with its composition and main types.

Structure

Polyurethane foam is a one-component polyurethane-based sealant. It is in great demand, because without it it is impossible to install doors, windows, as well as various repair processes. It is very convenient to work with the material, since no mechanisms or energy sources are needed. It does not matter what kind of foam (Macroflex, Titan, etc.) is used - it penetrates into all cavities and completely hardens in a few hours.

It is supplied in cylinders as a liquid prepolymer and propellant. After the release of the contents, it begins to launch which is responsible for moisture in the air and on the treated surface.

Specifications

Before figuring out how much polyurethane foam dries, you need to familiarize yourself with its amazing characteristics.

Varieties

Depending on the method of application, the foam is professional and household. According to the temperature of use, it is divided into summer, winter and all-season. The professional composition differs in that it is applied with a pistol (there are special valves on the cylinder). Why is it called professional? Because a gun costs much more than foam (every 10 times), and there is no point in purchasing it for a single use (used only by professionals).

Foam (characteristics are presented above) for household use is used without any devices. To spray it, you will need a special tube, which is present on each cylinder.

Summer foam can be applied to surfaces with a temperature of +50 ... + 350 degrees. The working temperature of the winter material is from -180 to +350 degrees. Moreover, its volume after application and expansion decreases with a decrease in the temperature regime. All season foam has the best qualities of summer and winter. It allows you to work at low temperatures with higher yields and faster solidification.

How is polyurethane foam used and how long does it dry?

It is considered an amazing insulating material that is specially designed for:

• filling cracks in rooms without heating, roofing;
• filling gaps around various pipes, doors and windows;
• fixing doors and windows without additional fasteners;
• attaching thermal insulation materials to walls;
• sound insulation of pipes, air conditioners, hoods, etc .;
• widespread use in the renovation of premises;
• filling gaps in boats, rafts, etc.

In order for the material to perform its functions well and serve as long as possible, it is necessary:

• to close seams and cracks up to 80 mm wide (large gaps are first filled with boards, bricks);
• spray the surface with water for better adhesion (before and after application);
• shake the bottle before work and keep it upside down;
• fill the gap not completely (by 1/2 or 2/3), thereby reducing the consumption of polyurethane foam;
• cut off excess after polymerization (time of complete hardening - 24 hours);
• protect the surface from the sun with any paint;
• use only high quality products of a well-known brand.

Consumption

750 ml cylinders typically have an output of 50 liters. But this does not mean that they can fill a fifty-liter container. Foam is considered unstable due to the large number of bubbles. Under its own weight, the lower layers burst in it, as a result of which the volume decreases. In this regard, a fifty-liter output is considered a conditional norm, which is true when filling gaps with a width of no more than 20 mm.

Each cylinder is filled with polyurethane in a solvent and liquefied filler gas, which after reaction with open air takes up a space of 50 liters. Please be aware that volume reduction can occur if the material is used at low temperatures. As a result, the consumption of polyurethane foam indicated on the label corresponds to reality only in ideal conditions.

How to choose

Before choosing a material, you need to decide on the conditions in which the work will be performed. It is also important what it will be used for: for sealing, sound insulation, insulation or installation. When buying, you should pay attention to who the foam was made by. Customer reviews recommend paying attention to the brands Titan, Soudal, Penosil, Makroflex.

As for the designs, for example, any foam is suitable for plastic windows, but you will have to decide on the characteristics. It is best to apply the material with a gun, but for a single use, you can stop at the plastic tube. If you have to process large spaces, you should choose professional formulations in massive cylinders.

Content

Polyurethane foam belongs to the group of sealing agents, without which it is impossible to do during the construction process. It is used in cases when it is necessary to seal seams / joints more than 3 cm. You can often stumble upon the question "How much polyurethane foam dries", but it turns out that it is not quite correct. The fact is that the secret of transforming the prepolymer into strong polyurethane foam lies in the degree of its wetting.

Expansion ratio

The main feature of the described building material is its ability to expand several times. If we talk about household foam, then its coefficient of increase in volume reaches 60%, in professional formulations it can be all 300%

Attention! The same types of material can behave very differently, and this is determined by environmental conditions. We are talking about the temperature of the air, its humidity, the type of application, the speed of the release of the foamy composition from the container. Manufacturers always indicate overestimated volumes of output, but you should not be guided only by them.

Before you figure out how long the foam dries, let's consider its types. It can be primary, i.e. the prepolymer begins to expand directly upon application to the surface. As the name implies, secondary expansion lasts throughout all stages of the transformation of a high molecular weight compound. This should always be remembered when using such building materials.

The ability to expand is not the only characteristic. How much polyurethane foam dries in an apartment sometimes depends on the degree of its shrinkage, which rarely reaches 5%. If this happens, then most likely you are using substandard materials. Be prepared for the fact that a mass break may even occur. Each master selects the best option for himself, taking into account his needs. If the expansion ratio is in the first place for you, then the products Macroflex, Moment, GoldGan, Macrosil are suitable.

Detailed description of the sealant

Interesting! This type of sealant in the construction industry began to be used recently, but despite this, it quickly replaced competitors.

The advantages of polyurethane foam include:

• easy application;
• affordability;
• durability.

Initially, it was said that water plays a major role in the hardening process of the sealant. It is under its influence that the level of adhesion increases, therefore experts recommend pre-wetting the working surfaces. If you are interested in how much foam dries when installing doors, then keep in mind that this indicator is influenced by the thickness of the layer, the air temperature. With optimal performance, completely dried excess pieces of material can be cut off after 3 hours, and start plastering. As for the final polymerization, it lasts for another 12 hours. In cold and dry weather, the process can take an indefinite amount of time. One thing is for sure that it is possible to proceed to the next stage of work only after the porous mixture has completely solidified.

If you are not satisfied with how much foam dries when installing windows, you can speed up the process. To do this, you need to periodically spray the sealant (moisten it in any way that is convenient for you). Do not forget that despite the many advantages, polyurethane foam is afraid of the sun's rays, so at the first opportunity it must be protected from them by plastering.

Do not forget about precautions, this will avoid unpleasant consequences.

Polyurethane foam is actively used in construction due to its ability to get into hard-to-reach places, provide good sealing and isolation from extraneous sounds. In order for it to be able to show all its properties when installing doors, it is necessary to correctly calculate the time for its drying. About how much polyurethane foam dries when installing doors and its other "secrets", read on.

What you need to know about polyurethane foam

Polyurethane foam is a one-component polyurethane sealant. This substance is actively used in the installation of windows, doors and other repair work. Regardless of the brand of the product, it tends to get into all the cracks, and only after a few hours it completely hardens.

Specifications

In hardware stores, the product is available in the form of liquid formulations and gas cylinders to displace them. The capacity of the cylinders can be 300, 500 and 750 ml. To seal a classic doorway with a space of 5 cm between the frame and the wall, a cylinder with a capacity of only 300 ml should be enough.

Assembly foam for sealing joints in a 0.85 liter can is also sold. Such a volume is convenient for those who insulate walls or ceilings - or for other purposes, for the implementation of which you need to foam everything and a lot at once.

The general characteristics of the vast majority of the varieties of compositions that are offered by the domestic manufacturer are the following points:

• Ability to resist fire - at least B3.

Note: And this is not good, since this class eloquently answers the question: "Does the polyurethane foam burn after drying?" Yes, it is burning, and how! If this characteristic is so important for you, then it is best to use fire-fighting compounds that also burn, but less intensely and prevent the spread of fire, for example, like Titan B1.

• Heat conductivity - 0.036 W.
• The probability of rupture when the material is pulled is 13/17%.
• The shear strength of a flat surface is 90/40 kPa.
• The appearance of foam on the surface. Dry - 130/30%, wet - 200/80%.
• Hygroscopicity - 0.3%.
• Temperature conditions for use range from -40 to + 90 ° C.
• The processing time is 60-45 minutes.
• Surface grip: good grip on wood, metal, plastic and glass. Poor adhesion to polyethylene, silicone and similar surfaces.
• Reaction to direct sunlight. The foam is destroyed by direct exposure to ultraviolet rays, therefore protective substances are applied to the material layer.
• Primary expansion is the ability of the foam to fill in empty areas at the start of application.

Note! Secondary expansion refers to the negative qualities of the product. With improper use and inaccurate compliance with the necessary conditions, the foam can significantly expand in volume, disrupting the overall organic nature of the construction process.

Properties

For the successful implementation of work, the essence of which is to fill empty areas, heat insulation of premises, install doors, windows and carry out sound insulation, the polyurethane foam must have the following quality properties:

1. Good elasticity for even distribution of the substance on the surface of voids.
2. Low shrinkage factor readings.
3. When placing materials on a foaming surface, it must have high adhesion characteristics of the materials.
4. Resistance to temperature extremes and other external factors affecting the material.

Most of the products on the market have these properties, but there are also products manufactured by unscrupulous manufacturers. These products are of poor quality and are not suitable for demanding renovation work.

When purchasing such a product, after using it, you can seriously ask yourself why the polyurethane foam crumbles immediately after hardening, and then it is fragile, like porcelain.

Remember, a good quality product cannot be cheap, since in order to achieve this level, you have to spend a lot on modernizing production, purchasing good raw materials and hiring first-class specialists. And all this is invested in the final cost.

In order to purchase quality material, we recommend that you request a product quality certificate from the seller. In case of refusal to provide the document, you need to doubt its quality and refuse to purchase an incomprehensible product. Or simply, purchase already proven brands, for example, "Macroflex" or "Titan".

How is foam used

Delicate like marshmallows - but this is not for long, after hardening, it turns into a real rusk

Polyurethane foam is one of the most important products used in construction for a variety of jobs.

These include:

• filling large cracks in unheated rooms;
• sealing holes in pipes, walls, windows and doors;
• installation of windows and doors and their adhesion to brick or concrete surfaces;
• attaching heat insulation materials to the wall;
• sound insulation of pipes, hoods and other elements;
• renovation work in the rooms;
• filling holes in a boat, etc.

But, of course, it is better not even to think about such an application as shown in the photo above (or something similar). Otherwise, you have to shoot all this extravagant beauty with a scalpel. And here the question is not how long the polyurethane foam hardens, but how to get rid of it as soon as possible with minimal losses.

Drying time of polyurethane foam

And, let's move on to the most interesting thing, for the sake of which we have gathered here today - what should be the time for the drying of the polyurethane foam to such a state that you can use the elements of the entire, let's say, walled up system, without damaging its parts.

Firstly, how long the polyurethane foam dries depends on the volume of the crack. Secondly, from the temperature conditions, and thirdly, from the humidity of the room.

Note! Foam hardens faster at high humidity levels than in dry rooms. Many craftsmen prefer to wet the cracks with water before applying a foam to improve the adhesion of the product to the surface.

Professional polyurethane foam, placed in a 3 cm crack, hardens within half an hour, and household foam takes about an hour to harden for such a gap. Complete drying of the material takes about a day.

In the event that the room is humid and warm, the complete curing of the foam can occur twice as fast, namely 12 hours after application.

To speed up the drying process of polyurethane foam will help its periodic spraying or watering. After the material is dry, cut off the excess protruding particles and cover it with plaster or any other compound that will protect the foam from harmful contact with direct ultraviolet rays.

Note! The drying time of the polyurethane foam largely depends on the humidity in the room. So, with a decrease in air temperature, humidity also decreases, which leads to a slowdown in the drying process of the foam. In a dry room, complete drying of the composition will take about 24 hours. If the foam was used at low temperatures, and even in humid conditions, for example, in the fall on the street, then this interval can double, if not triple.

Average consumption

The output of cylinders with a volume of 0.75 liters is 50 liters. This figure is not so great if we take into account the properties of the foam: under the influence of its weight, it settles, and the bubbles in the lower part of the solution burst.

This leads to a decrease in the volume of the material. Considering these characteristics, fifty liters of cylinder outlet is enough to fill cracks of 2 cm in size.

Each cylinder contains a certain amount of polyurethane with a solvent and a special gas, which takes up 50 liters of space after contact with air. With a later drying of the polyurethane foam, this gas is released to the outside.

When using the product in low temperature conditions, it must be taken into account that its volume will noticeably decrease. Therefore, the volume of the product indicated on the packaging will exactly correspond to the indicated figure only if the ideal conditions for working with polyurethane foam are observed.

5 conditions that will help you choose polyurethane foam for "home" and professional work

In order to get acquainted with the purchased product, it is necessary to conduct its initial testing before the implementation of serious work.

To do this, you need to know the following indicators of product quality:

• The consistency of the composition should be a collection of closed cells, which are covered with a thin film on top. Foam shrinkage should not exceed 5%.
• It is necessary to pay attention to the release of foam in the purchased cylinder. Thus, the foam output in a 750 ml bottle is only 50 liters, which may not be enough for large volumes of work. In home repair work, the output of foam with a volume of 50-60 liters should be enough, and in professional conditions, the purchase of products with a volume of 300% of the output is most often preferred.
• The viscosity of the composition. The chemical compounds that make up the foam form a single consistency, which should have its own standard for repair work, namely, it should not be too liquid.
• Bonding of the assembly material with other substances. To do this, apply it to wood, stone, or concrete. Silicone and polyethylene surfaces are not suitable for testing, as they certainly do not allow for normal adhesion.
• Pay attention to the usability of the cylinder and its type. It is also important to calculate the amount of the mixture that will remain on the bottom after the repair.

It is necessary to study the substance under suitable conditions - namely, at a temperature of 5 to 30 degrees Celsius. It is important to provide the room with a suitable humidity level. So from experience you can deduce on your own how much foam of a particular brand solidifies. If these recommendations are not followed, the quality characteristics of the purchased mixture may significantly decrease.

At the same time, when testing how long the polyurethane foam dries, do not forget about observing safety rules. Wear a protective suit and prevent foam from getting into your eyes. Otherwise, the eyes should be rinsed and a doctor immediately consulted.