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Foam glass is a porous glass foam material. Its advantages as a building material include its light weight, high strength, and thermal and acoustic insulating properties. It is made by heating a mixture of crushed or granulated glass and a blowing agent (chemical foaming agent) such as carbon or limestone. Near the melting point of the glass, the blowing agent releases a gas, producing a foaming effect in the glass. After cooling the mixture hardens into a rigid material with gas-filled closed-cell pores comprising a large portion of its volume.
As to chemical foaming agents, there are several additives that facilitate the release of the gaseous phase upon heat treatment. [1] [2] [3] [4] In general, these additives are categorized into two categories: a) redox and neutralization agents, and b) decomposing agents. Redox and neutralization agents include nonoxide materials, e.g. carbides or nitrides. Decomposing agents include sulfates, e.g. CaSO4•nH2O,[ citation needed ] organic compounds, and carbonates, e.g. CaCO3. These materials release gas following decomposition and/or burning.
In the 1930s, Saint-Gobain of France first developed foam glass with calcium carbonate as a foaming agent. In 1932, it applied for a patent. [5]
An early report of foam glass as a construction material was made by the Soviet scientist, Professor Isaak Ilych Kitaygorodskiy (ru) at the All-Union Conference on Standardization and Manufacture of New Construction Materials in Moscow in 1932. [6] Subsequently, in 1939, the Soviet Union reports experimentally produced foam glass at the intermediate pilot plant of the Mendeleev Institute of Chemical Technology. A glass powder screened through a 0.09 mm mesh was mixed with limestone and later on with anthracite and coal as gasifier. [7]
The product that is known today as Foamglas cellular glass insulation, was developed by Pittsburgh Corning and was later acquired by Owens Corning. It is made of cullet, foaming agent, modified additive and foaming accelerator. After fine pulverization and uniform mixing, it is melted at high temperature, foamed and annealed. An inorganic non-metallic glass material, it consists of a large number of uniform bubble structures with a diameter of 1 to 2 mm. Sound-absorbing Foamglas insulation is more than 50% open cell bubbles, and heat-insulating Foamglas is more than 75% closed-cell air bubbles, which can be adjusted according to the requirements of use through changes in production technical parameters. [8] Similar products by other manufacturers are sold as 'cellular glass' or 'foam glass'.
Because this material is moisture-proof, fireproof, and anti-corrosive, and the glass material has the advantages of long-term use performance, it is favored for uses in harsh environments such as in heat insulation, deep cooling, underground, open-air, flammable, damp, and under chemical attack. It is widely used in wall insulation, petroleum, chemical industry, machine room noise reduction, highway sound absorption barrier, electric power, military products, etc. and is called green environmental protection insulation material by users.[ citation needed ]
Depending on the properties of the foam glass, it can be used as insulation material in various sectors of construction engineering, as well as in shipbuilding, chemical, cryogenic, and high-temperature technologies. White and stained glass are also used as sound absorbing and decorative materials. Waste in production – foamed glass powder and scrap can also be used as fillers for decorative light concrete and other applications. Depending on the application, foam glass products produced by the corresponding processes can be divided into four categories, namely insulating foam glass, sound-absorbing decorative foam glass, facing foam glass, and granular foam glass.[ citation needed ]
Foam glass is a kind of lightweight, high-strength building material and decorative material with excellent performance (insulation) and sound absorption that is both moisture-proof and fireproof. The temperature range is from -196 degrees to 450 degrees Celsius. Although other new insulation materials emerge in an endless stream, foam glass occupies an increasingly important position in the fields of low thermal insulation, moisture-proof engineering, and sound absorption due to its permanence, safety, and high reliability. Its production is the recycling of waste solid materials, which is an example of protecting the environment and obtaining substantial economic benefits. Recently, it is available in monolithic dimensions of 2.8 x 1.2m.[ citation needed ]
Lava foam glass: natural lava such as obsidian and industrial waste slag is used as the base material, and a certain amount of glass powder can also be added to reduce the foaming temperature and foam glass made of or the like as a foaming agent. Generally used as insulation materials and wall materials for construction and industrial equipment. [9]
Foam glass is fireproof, waterproof, non-toxic, corrosion-resistant, anti-mite, non-aging, non-radioactive, and insulating. Anti-magnetic wave, anti-static, high mechanical strength, with good adhesion to various types of mud. It is a stable building exterior wall and roof insulation, sound insulation, and waterproof material.
According to reports, foam glass can be used in places that require sound insulation and heat insulation, leak prevention and flood control. It has functions for home cleaning and health care. The use of foam glass to protect the heating duct reduces heat loss by approximately 25% compared to conventional protective materials. [10]
Foam glass, also known as porous glass, is filled with numerous open or closed small pores. The area of the pores is 80%~90% of the total volume, and the pore size is 0.5~5mm, and some are as small as a few microns.
1. The matrix of the foam glass is glass, so it does not absorb water. The internal bubbles are also closed, so there is no capillary phenomenon and no penetration, so foam glass is currently the most ideal thermal insulation material. [ citation needed ]
2. The mechanical strength is high, and the intensity change is proportional to the apparent density. It has excellent pressure resistance and can withstand the erosion and load of the external environment more than other materials. The combination of excellent compression resistance and moisture barrier properties makes foam glass an ideal thermal insulation material for underground pipelines and tank foundations. [ citation needed ]
3. Foam glass has good thermal and moisture permeability, so thermal conductivity is stable for a long time, and it does not change due to environmental influences, and the thermal insulation performance is good.
4. Foam glass is a matrix wet glass, so it will not burn spontaneously and will not be burned. It is an excellent fireproof material. Foam glass has an operating temperature range of -200 to 430 °C, a small expansion coefficient (8 × 10 °C) and is reversible, so the material properties are unchanged for a long time, are not easy to embrittle, and have good stability.
5. Foam glass has good sound insulation performance and strong absorption of sound waves. The average penetration loss is 28.3 dB in 60~400 Hz.
6. The dyeing property of foam glass is good, so it can be used as insulation decoration materials.
Foam glass insulation aggregate is used in the same way as coated clay aggregate but is capable of being used as a load-bearing hardcore. It also offers better insulation (lambda/k value = 0.08 – approximately 20% lower thermal conductivity than lightweight expanded clay aggregate). It therefore needs less depth for similar thermal performance. [11]
A ceramic is any of the various hard, brittle, heat-resistant, and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcelain, and brick.
Thermal insulation is the reduction of heat transfer between objects in thermal contact or in range of radiative influence. Thermal insulation can be achieved with specially engineered methods or processes, as well as with suitable object shapes and materials.
Sintering or frittage is the process of compacting and forming a solid mass of material by pressure or heat without melting it to the point of liquefaction. Sintering happens as part of a manufacturing process used with metals, ceramics, plastics, and other materials. The nanoparticles in the sintered material diffuse across the boundaries of the particles, fusing the particles together and creating a solid piece.
In materials science, a refractory is a material that is resistant to decomposition by heat or chemical attack and that retains its strength and rigidity at high temperatures. They are inorganic, non-metallic compounds that may be porous or non-porous, and their crystallinity varies widely: they may be crystalline, polycrystalline, amorphous, or composite. They are typically composed of oxides, carbides or nitrides of the following elements: silicon, aluminium, magnesium, calcium, boron, chromium and zirconium. Many refractories are ceramics, but some such as graphite are not, and some ceramics such as clay pottery are not considered refractory. Refractories are distinguished from the refractory metals, which are elemental metals and their alloys that have high melting temperatures.
Memory foam consists mainly of polyurethane with additional chemicals that increase its viscosity and density. It is often referred to as "viscoelastic" polyurethane foam, or low-resilience polyurethane foam (LRPu). The foam bubbles or ‘cells’ are open, effectively creating a matrix through which air can move. Higher-density memory foam softens in reaction to body heat, allowing it to mold to a warm body in a few minutes. Newer foams may recover their original shape more quickly.
A vacuum insulated panel (VIP) is a form of thermal insulation consisting of a gas-tight enclosure surrounding a rigid core, from which the air has been evacuated. It is used in building construction, refrigeration units, and insulated shipping containers to provide better insulation performance than conventional insulation materials.
In materials science, the sol–gel process is a method for producing solid materials from small molecules. The method is used for the fabrication of metal oxides, especially the oxides of silicon (Si) and titanium (Ti). The process involves conversion of monomers in solution into a colloidal solution (sol) that acts as the precursor for an integrated network of either discrete particles or network polymers. Typical precursors are metal alkoxides. Sol–gel process is used to produce ceramic nanoparticles.
Bioactive glasses are a group of surface reactive glass-ceramic biomaterials and include the original bioactive glass, Bioglass. The biocompatibility and bioactivity of these glasses has led them to be used as implant devices in the human body to repair and replace diseased or damaged bones. Most bioactive glasses are silicate-based glasses that are degradable in body fluids and can act as a vehicle for delivering ions beneficial for healing. Bioactive glass is differentiated from other synthetic bone grafting biomaterials, in that it is the only one with anti-infective and angiogenic properties.
In materials science, a metal foam is a material or structure consisting of a solid metal with gas-filled pores comprising a large portion of the volume. The pores can be sealed or interconnected. The defining characteristic of metal foams is a high porosity: typically only 5–25% of the volume is the base metal. The strength of the material is due to the square–cube law.
Low emissivity refers to a surface condition that emits low levels of radiant thermal (heat) energy. All materials absorb, reflect, and emit radiant energy according to Planck's law but here, the primary concern is a special wavelength interval of radiant energy, namely thermal radiation of materials. In common use, especially building applications, the temperature range of approximately -40 to +80 degrees Celsius is the focus, but in aerospace and industrial process engineering, much broader ranges are of practical concern.
Building insulation is material used in a building to reduce the flow of thermal energy. While the majority of insulation in buildings is for thermal purposes, the term also applies to acoustic insulation, fire insulation, and impact insulation. Often an insulation material will be chosen for its ability to perform several of these functions at once.
Ceramic foam is a tough foam made from ceramics. Manufacturing techniques include impregnating open-cell polymer foams internally with ceramic slurry and then firing in a kiln, leaving only ceramic material. The foams may consist of several ceramic materials such as aluminium oxide, a common high-temperature ceramic, and gets insulating properties from the many tiny air-filled voids within the material.
A blowing agent is a substance which is capable of producing a cellular structure via a foaming process in a variety of materials that undergo hardening or phase transition, such as polymers, plastics, and metals. They are typically applied when the blown material is in a liquid stage. The cellular structure in a matrix reduces density, increasing thermal and acoustic insulation, while increasing relative stiffness of the original polymer.
Building insulation materials are the building materials that form the thermal envelope of a building or otherwise reduce heat transfer.
Spray foam is a chemical product created by a chemical reaction of two component parts, commonly referred to as side A and side B. Side A contains very reactive chemicals known as isocyanate. Side B contains a polyol, which reacts with isocyanates to make polyurethane, and a mixture of other chemicals, including catalysts, flame retardant, blowing agents and surfactants. These react when mixed with each other and expand up to 30-60 times its liquid volume after it is sprayed in place. This expansion makes it useful as a specialty packing material which forms to the shape of the product being packaged and produces a high thermal insulating value with virtually no air infiltration.
Pipe Insulation is thermal or acoustic insulation used on pipework.
Rigid panel insulation, also referred to as continuous insulation, can be made from foam plastics such as polyurethane (PUR), polyisocyanurate (PIR), and polystyrene, or from fibrous materials such as fiberglass, rock and slag wool. Rigid panel continuous insulation is often used to provide a thermal break in the building envelope, thus reducing thermal bridging.
Foam concrete, also known as Lightweight Cellular Concrete (LCC) and Low Density Cellular Concrete (LDCC), and by other names, is defined as a cement-based slurry, with a minimum of 20% foam entrained into the plastic mortar. As mostly no coarse aggregate is used for production of foam concrete the correct term would be called mortar instead of concrete; it may be called "foamed cement" as well. The density of foam concrete usually varies from 400 kg/m3 to 1600 kg/m3. The density is normally controlled by substituting all or part of the fine aggregate with the foam.
Aerogels are a class of synthetic porous ultralight material derived from a gel, in which the liquid component for the gel has been replaced with a gas, without significant collapse of the gel structure. The result is a solid with extremely low density and extremely low thermal conductivity. Aerogels can be made from a variety of chemical compounds. Silica aerogels feel like fragile styrofoam to the touch, while some polymer-based aerogels feel like rigid foams.
Titanium foams exhibit high specific strength, high energy absorption, excellent corrosion resistance and biocompatibility. These materials are ideally suited for applications within the aerospace industry. An inherent resistance to corrosion allows the foam to be a desirable candidate for various filtering applications. Further, titanium's physiological inertness makes its porous form a promising candidate for biomedical implantation devices. The largest advantage in fabricating titanium foams is that the mechanical and functional properties can be adjusted through manufacturing manipulations that vary porosity and cell morphology. The high appeal of titanium foams is directly correlated to a multi-industry demand for advancement in this technology.
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