Spray foam is a chemical product made by two materials, an isocyanate and a polyol resin, which reacts when mixed with each other and extends up to 30-60 times the volume of the liquid after being sprayed in place. This expansion makes it useful as a special packaging material that forms a packaged product form and generates high thermal insulation value with virtually no air infiltration.
Video Spray foam
Histori
Otto Bayer (1902-1982) was credited with the invention of polyurethanes in 1937. He successfully synthesized polyurethane foams by exploring the basic idea that mixing small volumes of chemicals could create a dry foam material.
Polyurethane is further developed for different applications, ranging from shoe soles and cushions to industrial uses. In the 1940s rigid foams were applied to aircraft, and in 1979 polyurethane began to be used as building insulation.
Maps Spray foam
Properties
Thermal resistance
The R-value is the term given for thermal resistance to heat flow. The higher the R value of an insulating product, the more effective the insulating properties. The spray polyurethane foam comes in various densities and cel structures. The low density foam is referred to as Open Cel SPF while the higher density foam is referred to as Closed Foam foam. 1.8-2 pounds of polyurethane foam has the highest R value of spray foam insulation available in homes and buildings.
Polyurethane is a closed cell foam insulation material that initially contains low conductivity gas in its cells. As a result of the high heat resistance of the gas, polyurethane spray isolation typically has an initial R value of about R-3.4 to R-6.7 per inch. By comparison, the blown fiberglass usually has a R value of only R-3 to R-4 per inch.
The insulating foam blocks all three forms of heat transfer:
- Conductive heat transfer
- The flow of thermal energy through a substance from a higher to a lower temperature region. Thermoset foam plastics reduce conductive heat transfer because some have very loose molecular bonds; In addition, well-fitted spray foam cells are filled with air in the case of open cell foam or 245fa in closed cell foam.
- Radiant heat transfer
- The process by which heat energy is in the form of light (usually IR unless the substrate is hot enough to glow within the visible range) is emitted stronger by a warm surface and absorbed by other materials especially from low IR reflectivity (think matte black finish). Radiation heat transfer does not require media. Foam insulation materials, such as spray foam insulation, do not penetrate thermal radiation, like most solid materials.
- Convective heat transfer
- Heat created elsewhere that is transported through a liquid, such as water or in our case air. The most important spray spray spray attribute is the ability to seal the air creating a special airtight envelope inside the building structure. An additional benefit for air sealing is the ability to block convective heat transfer from the interior to the exterior during the warming month and vice versa during the cooling months, since heat can not escape through the gaps in the building envelope without the aid of air movement from infiltration as a means of transport.
Apps
Packaging app
Spray foam is a very specialized packaging material, often required for use in the delivery of valuable fragile items. The designed packaging principles are designed to protect sculptures, vases, large fossils, lamp base, sculptures, computers, furniture, pendants and other objects with unusual shapes. Based on the liquid foam that extends up to 30-60 times the volume of the liquid, it efficiently protects almost any size, shape and weight.
Suitability of mold, up and down, bearing a safe and uniform on the object. There are many different types of alternative materials that can be used to address more specific needs.
Build app
Spray spray spray or spray polyurethane foam (SPF) is an alternative to traditional building insulation such as fiberglass. A mixture of two components comprising the isocyanate and polyol resins united at the tip of the rifle, and forming an enlarged foam sprayed onto a tile, concrete slab, into the wall cavity, or through a hole drilled into the wall's finished cavity.
"Spray foam" is also an informal term used to refer to various plastic foam materials used in building construction to provide thermal insulation and minimize air infiltration. Polyurethane and polyisocyanurate are the two types of foam used in this application.
Type
Spray foam polyurethane (SPF) insulation can be categorized into two different types: open cell foam insulation with light density and medium density spray foam insulation. Both SPF types are thermoset cellular plastics consisting of millions of small cells.
Isolation of open cells can be destroyed in your hands and has a lower insulation value. The cell is closed stiff to the touch and every air cell is completely closed. While the closed cell foam has a higher R value, it is more expensive to buy.
Medium-Density Closed-Cell Spray Foam (ccSPF)
Medium-density cell-covered foam insulation is often referred to as two pounds (2 Â £ lb) of foam. It is a rigid insulating material with a Term Term Term Resistance (LTTR) rated R value that ranges from 5.1 to 6 per inch. When the minimum required thickness of 50 mm is attached, ccSPF is a vapor barrier and an air barrier.
In Canada, the National Building Code refers to two standards applicable for the manufacture and installation of ccSPF: CAN/ULC Material Standard S705.1 and CAN National Application Standards/ULC S705.2. Standard installation requires that all ccSPF installers in Canada be licensed and carry a photo ID.
Normally the natural color of the foam is yellow, but in Canada all ccSPF that has a mandatory CCMC list has a unique color for field identification.
Light-Density Open-Cell Spray Foam (ocSPF)
SPF with SPF light density is commonly known as half pound foam. It is a semi-rigid material with a sponge-like appearance that expands during installation and creates a small open cell filled with carbon dioxide. Because of its ability to expand during the application process, it fills cracks, cracks and cavities and adheres to irregular surfaces or substrates to form air sealing insulation.
While R values ​​will vary, most ocSPF products have an R value of about 3.8 per inch. Unlike medium-density closed cell SPF, ocSPF is not a vapor barrier. When installed at 5.5 inches or more, ocSPF acts as an air barrier. It is often used for interior walls as it provides noise reduction by blocking and absorbing air leaks. Usually only recommended for indoor applications.
Application method
Asia
A type of usage well known in Southeast Asian countries is to apply a pu or pur foam by spraying it to the bottom of the roof tiles under high pressure with a spray gun. The hard but flexible rigid foam layers are then fabricated and sealed all the tiles against each other and into the steel structure.
This spraying method, especially very popular in Thailand, is used not only against heavy leaks but also helps as an insulator against the enormous heat that ceaselessly faces the roof.
This tropical heat is actually the cause that steel structures, most of the roofs in the world are built, expands and contracts over time. Thus, the steel structure destroyed by the sun causes the roof tiles to slip off and slowly creates a small opening between the tiles, where rainwater can go inside, creating leaks that can cause much damage to plastering and electrical wiring.
Polyurethane Foam provides a complete and seamless building envelope, creating a more comfortable indoor environment for your home life.
To avoid the cost of re-roofing homes that only suffer from nail fatigue, and to obtain optimal isolation, 85mm polyurethane foam layer can be sprayed onto the bottom of a whiteboard or tile from a pitched roof. It stabilizes and the roof is weatherproof by fixing the nails, battens and roof feels. Since the foam is a superior insulant, coupled with just 100mm insulation at the beam level, your roof will also meet the stringent thermal performance standards required for the new home. Typical roofs can be isolated using polyurethane treatment for about half the cost of re-roofing.
Isolation at the roof level will make your loft area comfortable to use and free of condensation. By installing insulation at the rafter level, create a warmer loft void and prevent the formation of condensation, which can occur if increased insulation on the ceiling. A warmer, drier, cleaner roof space eliminates the risk of freezing pipes and tanks.
Europe
Approximately 150,000 properties have been treated with polyurethane foam insulation in the UK. There are systems that have British Board of Agreement approval to use in existing and new development applications and may demonstrate compliance with Building Rules.
North America
The Canadian National Building Code refers to the National Application Standards CAN/ULC S705.2 to be followed during all installations of the medium density of 2lb of closed cell polyurethane foam. Each installer must have a license to spray the foam and hold a valid photo ID issued by a Quality Assurance Program provider (QAP) indicating that the license is in good condition. The largest provider of QAP for foam spray installers and contractors in Canada is a nonprofit organization called CUFCA.
The United States has adapted to the use of sprayfoam insulation and new technology called Wall Injection to retrofit existing wall constructions by drilling small holes between wall studs in framing structures and filling in voids with less aggressive water-based foams. This allows homeowners and businesses to save energy by making thermal envelopes in their existing structure.
Benefits
Insulating sponge foam, like other insulation, saves energy costs and lowers electricity bills. Studies by the US Department of Energy show that 40% of home energy is lost as a result of air infiltration through walls, windows and doors. Buildings treated with spray foam insulation insulation are as much as 50% better than traditional insulation products.
Properly deployed insulation can be part of the system design to protect against moisture protection, which provides the benefits of reducing the possibility of dangerous fungi, mold and rotting wood.
In addition to building temperature and humidity control, spray foam insulation is often used to reduce noise. Foam insulation serves as a barrier for air sound, and reduces the transfer of sound through the air through roofs, floors and walls of buildings compared to uninsulated structures.
In the United States, homes that are treated with spray foam insulation are often eligible for state and federal tax cuts.
Isolation of all types stops a lot of energy loss. Some types including spray foam also seal air leaks. Isolation can also save energy in hot climates by reducing the use of air conditioning.
The Effect of Climate Blowing Agent
Most closed-cell spray foams are now shaped using hydrofluorocarbon blowing agents (HFCs) that have high global warming potential, partially or completely offset the climate benefits of the energy savings they can offer. In the United States, HFC is scheduled to be removed in January, 2021. Several sponge foam suppliers have started supplying spray foam blown with HFO blower agents without this problem in early 2017.
Health effects
Insulating sponge foam is usually non-toxic only after healing. When curing spray foam emits gas that causes blurred vision and difficulty breathing. Using full face and breathing protection when applying the product is recommended.
Isocyanate is a strong irritant of the eyes and gastrointestinal tract and respiratory tract. Direct skin contact with the isocyanate may also cause marked inflammation. Some people say that their eyes feel like there is sand in them at the beginning of the problem. Some come out with a rash on their arms, chest, and neck.
Overexposure to isocyanates can make workers sensitive, getting them exposed to asthma attacks if they are affected again. Respiratory irritation may progress to chemical bronchitis. Additional exposures can make the onset easier with less isocyanates needed to launch an attack.
Sporadic cases of sporadic hypersensitivity (HP) pneumonitis are also reported in workers exposed to isocyanates. The symptoms may look like flu, with fever, muscle aches, and headaches. Other symptoms may include dry cough, chest tightness, and difficulty in breathing. Individuals with chronic HP often experience more progressive breathing, fatigue, and weight loss progressively. Individuals with acute HP usually develop symptoms 4 to 6 hours after exposure.
See also
- Building insulation materials
- Isolation (insulation material list)
- Value-R (isolation)
References
Source of the article : Wikipedia
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