Fire-fighting polyurethane foam is a type of polyurethane foam that has fire-resistant and fire-resistant properties. Thanks to these qualities, it is used at special facilities where strict adherence to fire safety requirements is necessary. Foam has special characteristics that imply specific rules of use. This article will tell you about the varieties of the polymer, the characteristics of the application and the criteria for choosing the material.
Fire-resistant polyurethane foam: characteristics and properties
A group of scientists under the leadership of Otto Bayer invented a specific substance with fire-resistant properties in 1947 quite by accident – during experiments with polyurethane. Then it was difficult to assume that polyurethane foam will find wide application in construction 70 years later.
Initially, such materials were used in industrial construction as insulating plates. In the 1970s, the British company Royal Chemical Industry invented foam cylinders, and their mass production began in the 1980s in Sweden. The invention came to Russia in the early 90s.
The main properties of the refractory foam are heat resistance and the ability to resist fire. Now it is often used for finishing slopes in openings during the installation of fire doors. Non-combustible substance, which fills the cracks, creates tightness and in case of fire prevents the penetration of smoke and burning into the room. Such requirements meet the fire safety rules.
Fire-resistant foam is not much more expensive than similar products, which are used in the installation and finishing works, so it is often used not only for its intended purpose, but also for other construction needs, even when high fire-resistance requirements are not placed on this object.
High refractory and technical characteristics of the assembly foam provides its composition, which includes:
- accelerating expansion catalysts, which provides the possibility of using foam even at sub-zero temperatures;
- foaming substances that affect the rapidity of solidification and the degree of porosity of the foam;
- stabilizing components that ensure uniform distribution of foam on the surface;
- gas, pushing the substance out of the vial.
Helpful advice! When buying fire fighting foam, you must make sure that you have a certificate of conformity. This document confirms its refractory properties.
The main and, perhaps, the only requirement for this type of fire protection products as provided for in the regulatory document is the level of resistance to fire. This indicator regulates the current GOST foam assembly 30247.0-94 – “Construction. Fire test methods. “
The document discusses the methods of testing building structures, materials, which are used in the construction and finishing of buildings, on fire resistance. Thus, the refractory mounting foam has a fire resistance limit of EI. This parameter indicates the passage of a check of the substance for integrity and the ability to maintain thermal insulation properties under intense fire exposure. The corresponding figure for products represented on the domestic market depends on its type and ranges from 60 to 360 minutes.
Virtually every type of construction work, be it the laying of engineering networks or cable communications, provides for the formation of openings. In the event of fire, not sealed openings become a direct way of spreading fire to adjacent rooms. In order to avoid disastrous consequences in the installation using fireproof plaster or a special material of basalt. In order to protect communications directly and prevent the advancement of fire, flame arresters and refractory couplings are used.
At present, along with the listed traditional materials, flame-retardant foam is used, which has managed to perfectly prove itself. This is evidenced by the characteristics of the foam. The main ones are:
- High resistance to fire, marked by EI (up to 360 minutes). This suggests that the foam is comparable to a fire wall.
- High adhesion – adheres well to almost all building materials. This substance is combined with brick, reinforced concrete, metal structures, cinder blocks, cement mortar, gypsum, glass, plaster and even ceramics used in wall decoration and for floor covering.
- Foam does not flow in the process of applying it to the wall.
- The use of mounting material allows you to do the job quickly and does not require special qualification skills.
- The material easily penetrates into the openings and holes and spreads throughout their volume, fills all cavities well.
- Rapid curing of the foam occurs at a temperature of from -18 to +35 ° C, which reduces the time required to complete the work.
- The material does not have secondary expansion properties.
Mounting refractory foam is long and reliable. It retains its characteristics in conditions of low air humidity. Unlike other substances, the foam does not crack under the influence of dry air. Conversely, in rooms with high humidity levels, it does not swell, and fungi and mold are not formed on it.
Helpful advice! Choosing products, it is necessary to determine its intended purpose. For fixing the door frame or window block, there is enough foam with an EI 60 fire resistance rating. Sealing the joints in the ceiling at the intersection of the chimney with a stove, fireplace or boiler requires a more reliable material. In this case, it is better to purchase foam with resistance to fire EI 240.
Fire-resistant foam reliably serves even in unheated warehouses, auxiliary facilities, engineering and industrial premises. Due to the wide temperature range of operation, which ranges from -40 to +100 ° C, the substance can be used in different climatic conditions, even in areas with significant temperature changes.
Due to the high thermal insulation properties of the foam does not allow air, heat, as well as smoke and gas mixtures. This quality is very important in terms of fire safety. A surface protective film forms very quickly on the material – approximately within 10 minutes. From one 750 ml vial under pressure 65 l of foam are released.
When choosing a mounting fire-fighting foam, the main attention should be paid to in which premises and in which areas its application is planned. It is important to consider the possibility of periodic heating of the structure and the likelihood of fire. These qualities affect the typical and species differences of the foam.
Depending on the possibility of using the substance at sub-zero air temperature, fire-resistant foam is divided into categories of use:
- at a temperature not lower than +5 ° C;
- at temperatures from -5 to -10 ° C.
Types of foam are distinguished by the level of fire resistance, which must correspond to the level of fire resistance of the doors. For example, marking on the foam EI 30, provides for its use in areas where up to 300 people can be at the same time and quick evacuation is possible.
Polyurethane foam has three fire resistance classes:
- class B3 – flammable foam;
- class B2 – combustible, but rapidly decaying foam;
- class B1 – non-flammable.
Fire-fighting polyurethane foam belongs to the class B1.
Given the presence of active components, the foam is divided into one- and two-component. Single-component refractory foam solidifies under the influence of water. Therefore, when using it, the surface is pre-moistened. Two-component fire fighting foam can harden without moisture. The use of such a substance is possible even in winter.
Manufacturers, in order to ensure fire resistance, add special chemicals to the foam – flame retardants. Their names and proportions are not disclosed in commercial interests. Polymerization of refractory foam occurs due to chemical reactions and when exposed to air and moisture. Products from different manufacturers differ in technical characteristics.
The modern market for foam manufacturers is quite extensive. Both foreign and domestic products are widespread. Below we consider the most popular companies that produce mounting foam.
It is interesting! Almost all imported products are manufactured in a unified volume of 750 ml cylinders and provides for the use of polyurethane foam under the gun.
In Russia, a one-component fire-resistant foam Profflex Firestop is produced. It is made under the German license. The substance is characterized by low secondary expansion and fast hardening with an EI 240 fire resistance coefficient, has a capacity (foam output) up to 65 liters. The price of such products – from 500 rubles. for the balloon. A more advanced equivalent is Proffelex Fireblok 65 foam.
Important! When removing the cylinder from the gun, it is necessary to remove the cylinder and gun valves from the face to avoid foam release (even if the gun and the cylinder are completely empty).
It is advisable to flush the gun once a month. If the tool is not used for a long time, then it must be mothballed. To do this, put a thin layer of technical petroleum jelly on it.
Polyurethane foam is widely used in various construction works. This sealant is often simply irreplaceable. Fire-resistant material is of particular importance, in particular when installing doors and windows or sealing openings after mounting communications. Proper use of foam and knowledge of the technological characteristics of the substance, which were described in this article, guarantee high quality work.