Polyurethanes are one of the most versatile plastic materials. The nature of the chemistry allows polyurethanes to adapt to solve challenging problems, to be moulded into unusual shapes and to enhance industrial and consumer products by adding comfort, warmth and convenience to our lives. Polyurethane insulation is used in many residential and commercial buildings. It is typically made by reacting an isocyanate, such as methyl diphenyl isocyanate (MDI) with a polyol blend. During the polymerization reaction, a blowing agent expands the reacting mixture. The final product is a solid, cellular polymer with high thermal resistance. Polyurethane insulation comes in open or closed cell form, in varying densities. It is typically installed as insulation on the roofs, walls, floors and ceilings of new and retrofit buildings. It is also used to insulate appliances, pipes and a variety of other products.
Rigid polyurethane foam is widely known for its excellent R-value, which is among the highest of any insulating material. This ensures efficient heat retention or alternatively, consistent temperature control of refrigerated or frozen environments. About half the energy used in the life of a building is for heating and cooling (Source: Energystar), so effective insulation is a major priority. According to the US Department of Energy, “residential and commercial buildings consume 40 percent of the energy and represent 40 percent of the carbon emissions in the United States. Building efficiency represents one of the easiest, most immediate and most cost effective ways to reduce carbon emissions.”
Air infiltration can account for 30% or more of a home’s heating and cooling costs (Source: US Department of Energy). PU insulation is stable and durable through the life of a building and does not settle and sag to reveal air gaps – unlike fibrous insulation products. Due to its closed cell nature, PU insulation performs as an air barrier, resulting in significant energy savings.
When polyurethane is bonded to facing materials e.g. plywood, OSB, metal or gypsum wallboard, high levels of both shear and compressive strength are achieved.
Rigid polyurethane foam can be factory produced in continuous block or batch form, or it can be produced on-site in spray and injection applications.
During the curing stage, rigid polyurethane foam is highly adhesive, allowing it to bond with many building facing materials. Bond strength is often higher than the tensile or shear strength of the foam. The adhesive strength of PU contributes significantly to an increase in the wind-uplift performance of a roof.
Rigid polyurethane foam is compatible with a majority of building facings including paper, fiberglass, aluminium, plywood, OSB, gypsum sheathing and foil. The many combinations available add to the inherent strength of the foam, allowing use in semi-structural panels and cladding.
Extreme temperature ranges of –328°F to +212°F can be tolerated by rigid polyurethane based foam products.
Rigid polyurethane foam has low water vapour permeability. Polyurethane foam products with a facing such as aluminium foil or polyethylene film, will perform as a vapour barrier preventing mould growth.
At low densities of about 2 lb/ft3, rigid polyurethane foam is made up of about 97% gas trapped in cells, and just 3% polyurethane polymer. The lightness of the material means reduced transportation costs and easy on-site handling and installation.
Rigid polyurethane foam provides excellent resistance to many common chemicals, solvents and oils.
Like all organic building materials (wood, paper, plastics, paints etc.), rigid polyurethane foam is combustible, although its ignitability and rate of burning can be modified to suit a variety of building applications. Local building codes must be consulted for guidelines on acceptable fire protection measures when installing polyurethane insulation products.
“A green building must be an energy efficient one”. Buildings currently waste a large proportion of the energy that goes into them. This energy heats up the earth instead of our homes, wastes money and increases our dependence on foreign energy supply. Buildings currently waste a large proportion of the energy that goes into them. This energy heats up the earth instead of our homes, wastes money and increases our dependence on foreign energy supply. Polyurethane insulation products reduce the demand for the fossil fuel based energy used to heat and cool buildings, thereby reducing the harmful greenhouse gases associated with the production and transportation of these fuels. In addition, in reducing energy demand polyurethane insulation offers a solution to the real concerns of fossil fuel scarcity and energy security.
Two distinct products offering similar benefits. Insulation board is made of a polyurethane foam core which can be faced with a wide variety of materials including paper, aluminium, Kraft, fiberglass, gypsum, perlite, oriented strand board (OSB) and fibreboard. Block is polyurethane foam which can be cut and shaped to the required dimensions. Both are used for a broad range of applications including cavity walls, flooring and roofing.
SPF is manufactured on-site by mixing and spraying reacting urethane chemicals onto the substrate. The spray foam expands to seal all cracks and crevices, providing a seamless air barrier. OCF is generally applied using small volume, pressurized containers. It is used to seal doors and windows in construction. SPF is the ideal insulant for energy efficient commercial and residential buildings. SPF creates a watertight and airtight seal directly against a substrate to eliminate the effect of air infiltration.
Insulated Metal Panels (IMPs) are factory manufactured exterior panels that are typically used for a wide range of commercial and industrial buildings. Applications include cladding, partitioning, load bearing walls and roofing elements. Panels are manufactured on a continuous lamination basis with metal facings (usually steel) encapsulating a foamed polyurethane core. The polyurethane foam thickness can reach eight inches, depending upon application and required insulation characteristics. These versatile products are also known as ‘sandwich’ panels due to the physical interaction of the two materials. This composite offers a high degree of stability, rigidity and excellent load bearing capacity.
Polyurethane foam used to insulate and protect heating and plumbing services within large diameter pipe systems. Typically used in municipal heating and offshore oil and gas pipelines. One of the main uses is in the insulation of oil and gas pipelines and district heating systems. Polyurethane foam insulation is also used in heating and plumbing services for power stations, chemical plants and refineries. In heating systems, polyurethane insulation prevents heat loss, and in cold climates it helps maintain a warmer pipe temperature to avoid freezing or cracking. Polyurethane insulation provides high mechanical strength, flexibility and it flows well when installed – which is important when filling long pipe sections.
‘Pour-in-Place’ insulation is a term used to capture a diverse range of rigid polyurethane foam applications. This category of products typically involves insulation of an item in a factory, by injecting polyurethane foam into a shell, cavity or space around the item. Although fragmented, it is a major market for polyurethane foam. Typical applications for Pour-in-Place insulation products include garage door panels, entry doors. Energy performance is a critical factor for specifiers, and this is usually measured in the final product by energy usage or heat leakage analysis. Achievement of these targets can be attained by the use of different blowing agent technologies, which produce specific performance characteristics in rigid polyurethane foam.
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