Open- and Closed-Cell Spray Polyurethane Foam Systems

Open and Closed Cell Spray Polyurethane Foam Systems The minimum thickness and maximum thermal insulation properties of polyurethane foams, combined with their water impermeability and air-tightness effects, enable the foam to provide thermal comfort and protection to buildings for many years. Perfect adhesion performance to the applied surface eliminates the need for additional installation work, preventing potential thermal bridge formation. Furthermore, buildings insulated with polyurethane foam benefit not only from energy efficiency but also from acoustic insulation. When classified morphologically, polyurethane foams are divided into two types: open and closed cell. Closed cell polyurethane foams provide mechanical strength and low thermal conductivity values, while open cell polyurethane foams offer advantages such as reduced load on the structure, low consumption rates, and sound insulation. Spray polyurethane foam, which has broad applications in the insulation sector, offers several advantages compared to other polyurethane foam applications. Due to ease of application, it has a lower operational cost advantage compared to alternative insulation materials. Depending on the experience of the operators performing the application and the nature of the surface being treated, a two-person crew can cover approximately 100 m² of area per hour with polyurethane foam. Furthermore, since spray machine dimensions are relatively small, they can be transported in a vehicle, and through hoses of varying lengths, the product can be applied to any area and any height. The quick setup time of the machine enables a two-person crew to perform applications in multiple locations on the same day. While spray foams offer many important advantages in terms of application, there are certain considerations that must be observed to prevent errors that may occur during application, which are detailed below. • Maintenance and Cleaning: Regular maintenance of the machine gun and equipment is of great importance. Particularly after application, the internal components of the gun and hoses must be cleaned of residue. • Application Surface Control: The cleanliness and dryness of the surface where application will take place are important. A wet surface reduces the adhesion performance of polyurethane foam, causing it to separate from the surface over time. On damp surfaces, blistering may occur on the polyurethane foam surface. Since polyurethane formation reaction is an exothermic reaction and heat is released during the reaction, application should not be performed on surfaces that may be affected by heat (surfaces that melt with temperature or have a glass transition temperature below 150°C). • Environmental Conditions: The dew point of the day and area where application will be performed should be checked. The temperature of the surface where application will take place must be a minimum of 3°C higher than the dew point. Application should not be performed on surfaces colder than 5°C. • Machine Control: The main parameters that should be checked on the machine before application are temperature and pressure. The pre-heating temperature of raw materials should be 45°C. The hose temperature should be 5°C higher than the pre-heating temperature. Raw materials brought to excessively high temperatures cause blockages at the gun tip. At low temperatures, dripping may be observed. Pressure should be set at 80-120 bar. When not working at the correct temperature and pressure, the most common problems are: dusting in the foam, lack of spray at the head, void formation in the foam, irregular cell distribution, and non-uniform application thickness. • Personal Protection and Safety: The catalysts, flame retardant agents, and blowing agents contained in the product have low boiling points. Some of them evaporate along with exothermic reactions. Inhaling these vaporized chemicals poses a health threat in both the short and long term. Therefore, it is essential that operators performing the application wear full-face safety glasses and a mask. Additionally, since blowing agents have low flash points, they are easily ignitable when exposed to flame sources. For this reason, the drum must not be approached with any flame source, and the drum must not be tampered with using sharp or piercing tools. Flokser Kimya, with the experience gained from serving many different sectors, provides effective solutions for spray polyurethane systems required in the insulation sector. Our open cell polyurethane foam systems, developed in our company and actively used in domestic and foreign markets, are shown in Table 1, while our closed cell systems are shown in Table 2. Creapol RS 2323-08 and Creapol RS 2320-18 are open cell, low-density polyurethane foam systems used for void filling purposes (Figure 1). The products reach a minimum thickness of 40 mm in a single coat. Due to their open cell structure, they are recommended for applications where mechanical strength is not expected. The Creapol RS 2323-08 product is preferred for its advantages in consumption rate and flame resistance, while Creapol RS 2320-18 is chosen for its easy adhesion to all types of surfaces and provision of uniform thickness. Despite its open cell structure, a skin layer formed on the outer surface ensures that the outermost layer of the product is hard. To control the dusting problem frequently encountered in low-density and water-based products, testing according to ASTM C421-08 standard on both products confirmed that the friability (dusting) value is below 1%. Open cell polyurethane foam systems contribute to sound insulation by dampening sound waves. While not recommended for use in areas exposed to loads and continuous water exposure, they are commonly used in the sector for void filling in inverted roof applications and interior facade walls. Furthermore, low-density products formulated as water-based do not contain solvents and are part of our environmentally friendly product technologies. Closed cell products are frequently preferred in applications demanding high strength and low thermal conductivity. They can be used during summer and winter months without causing problems such as separation from the surface or dripping. Compared to closed cell systems in our product range, Creapol RS 2327-30 offers approximately 15% consumption advantage. Through the bright skin it creates, it provides active insulation as long as it is not continuously exposed to water, and its structure does not contain halogenated blowing gases. *Reaction and working conditions were obtained as a result of measurements performed at 5°C with a mixer operating at 3000 rpm. Our product with code Creapol RS 2323-40 exhibits superior mechanical properties under temperature and humidity conditions. To determine this property, it successfully passed EN 1604 (Thermal insulation materials for buildings - determination of dimensional stability under specified temperature and humidity conditions) and EN1605 (Thermal insulation materials for buildings - determination of deformation under specified pressure load and temperature conditions) tests. Another product that will make a difference in the sector is Creapol RS 3323-30, our polyurethane foam system with high dimensional stability and low thermal conductivity value. Our product, which was determined to have E-class flame resistance through internal method testing, is manufactured from 35% recycled sources. Yusuf Yivlik R&D Specialist Flokser Kimya Serpil Güney R&D Director Flokser Kimya