Some types of polyurethane spray foams may create a special smell in the environment for a few days after application. This smell is usually caused by the presence of unreacted amine catalysts, which gives a fishy smell. However, this smell does not indicate a particular danger. It is recommended to use air conditioners for a few days after applying polyurethane spray foam in order to reduce this smell.

When the work surface is wet and humid, this moisture acts as a foaming agent that reacts with isocyanate and leads to the lack of combination of polyol and isocyanate in the required ratio, and as a result, the final foam will have poor physical properties and adhesion. When the foam is sprayed on a wet surface, there is a possibility of creating a weak cellular structure that does not adhere well to the wall and leads to gaps between the foam and the work surface. For this reason, it is very important to accurately measure the moisture level of the work surface before spraying polyurethane.

Polyurethane foam components, including polyol and isocyanate, must be combined in a one-to-one volume ratio. Increasing the share of isocyanate in the composition causes the foam to become hard and brittle, while the high proportion of polyol causes the foam to soften and probably creates a strong smell. Getting out of the one-to-one composition ratio is probably due to the device's inability to maintain the temperature of polyol and isocyanate materials in the temperature range recommended by the polyurethane raw material manufacturer, or the materials are contaminated by contact with other chemicals. Or their production date has passed. Defects in the spray foam device can also cause the lack of composition in this ratio. Sometimes, one of the polyol or isocyanate transfer pumps is defective, and as a result, the materials are not mixed in equal proportions at the spray nozzle head. If the pump does not provide enough pressure or heat before the material reaches the spray nozzle, the foam may not have enough heat and energy to fully react. Also, if the spray outlet nozzle is blocked by external factors or the diameter of the nozzle is too large, poly and isocyanate components will not mix well in the spray nozzle.

Despite the fact that each polyurethane foam manufacturer determines the temperature of the polyurethane spray surface based on the specifications of their materials, most polyurethane foam spray systems agree that the temperature of the spray surface should be above 10 degrees Celsius. Of course, by adding a catalyst to the materials, Ray foam can be adjusted for use in cold temperature conditions. However, spraying foam on a cold surface, which has a lower temperature than the limit recommended by the manufacturers, can cause the formation of a lacquer-like layer with a high density on the sprayed surface, which reduces the quality of foam adhesion. In some cases, the foam may completely separate from the surface due to the temperature difference between the two surfaces.

During the formation of polyurethane spray foam, some heat is produced, and if you do not pay attention to the recommendations of the polyurethane foam manufacturer, the excess heat may be trapped inside the foam and may not have enough time to escape from the foam. This heat can lead to the formation of foam with unfavorable quality that does not have sufficient performance in resisting the passage of thermal energy. The operator of spraying polyurethane foams should always follow the instructions provided by the manufacturers of polyurethane raw materials in order to choose the foam thickness and the time interval between two sprays in order to avoid the destruction of the foam due to the heat of the reaction. Of course, a certain amount of heat is always necessary to complete the curing process of polyurethane foam, but excess heat may lead to cracking and shrinking of the foam. The strange strong smell that is felt after spraying the foam is the result of the effect of this heat on the foam.

In case of unprincipled application of polyurethane spray foam, there is a possibility of the foam shrinking and separating from the work surface. Errors in the settings of the foam sprayer and spraying too much foam (outside the recommended thickness) can also cause the foam to shrink.

Like most coating paints, polyurethane spray foam must adhere to any surface that is clean, dry, and free of oil and grease. If the work surface is free of moisture, dust, oil and is used according to the principles taught by the polyurethane material manufacturer, there should not be any problem with the adhesion of the foam to the work surface. In order to ensure the adhesion of the foam to the surface, take a small sample of the foam with a cutter, and if it is hard to tear the sample and some foam remains on the surface, it indicates that there is no adhesion problem. If separating the foam from the surface requires applying force, but does not leave any traces of the foam on the surface and the work surface is completely clean, this type of so-called mechanical adhesion is called. But if the foam is easily separated from the surface, it indicates that the adhesion of the foam to the surface was weak.

Since the polyurethane foam injection machine as well as the air filter, as well as other foam injection machines, the appearance and style of construction are varied, and unfortunately and unfortunately the raw materials and supplies of the Cold Foam Injection Machine are fluctuating and changing the prices of the foam. Call our consultants