Fire resistance surface coatings

Chlorinated paraffins are versatile materials and are used in widely differing appHcations. As cost-effective plasticizers, they are employed in plastics particularly PVC, mbbers, surface coatings, adhesives, and sealants. Where required they impart the additional features of fire retardance, and chemical and water resistance. In conjunction with antimony trioxide, they constitute one of the most cost-effective fire-retardant systems for polymeric materials, textiles, surface coatings, and paper products. Chlorinated paraffins are also employed as components in fat Hquors used in the leather industry, as extreme pressure additives in metal-working lubricants, and as solvents in carbonless copying paper. 

Fire Retardant - In general a term that denotes a substantially lower degree of fire resistance than "fire resistive. It is frequently used to refer to materials or structures that are combustible but have been subjected to treatment or surface coatings to prevent or retard ignition of the spread of fire. 

Mastics are sprayed on a substrate in one or more coats, depending on the desired degree of fire resistance. The final coat of all fireproofing mastics should be rolled or brushed to provide a smooth surface finish. The material should be applied with a sufficient number of coats to prevent running or slumping and sufficient drying time should be allowed between coats. Mastics may also be hand-troweled, if permitted in the manufacturer s specifications. 

One coat of primer, formula 84-47, followed by fire-retardant white, formula 27. The primer, a zinc chromate alkyd type, intended for use by the Departments of the Army, Navy, and Air Force as a corrosion inhibitor tor metal surfaces, conforms with the requirements of specification JAN-P-735 (4). It is not formulated to be fire-resistant. The top coat, a semigloss inside fire-retardant paint intended primarily as a finish for interior bulkheads and overheads aboard ship, conforms with the requirements of specification JAN-P-702 (3). 

High efficiency in char formation is one of the reasons for the strong performance of Mg(OH)2 and A1(OH)3 as fire retarding additives. This performance can still be enhanced by surface coating the fillers with zinc hydroxystannate. Sb2O3 is volatized from the material and therefore does not affect char formation. Formation of char is an effective method of increasing the fire resistance of materials. The material which forms carbonaceous char has a reduced ability to supply the gaseous fuels required to fuel the fire. 

Application of fire-resistant coatings is one of the basic methods of protecting wood and other flammable materials from the influence of a fire and increased temperature. It is desirable to impart both short-term protection, to allow evacuation from a building, and long-term protection, to protect the surfaces from heat and fire damage and to prevent combustion. In recognition of the foregoing, various compositions have been developed that can add fire-retardant (-resistant) performance to substrates. 

Typical PlacemeTd Specifucaiions for Reinforcement. The minimum clear distance between parallel bars should be 2 times the side dimensions for square bars and 1 4 times the diameter for round bars. Reinforcement of footings and columns should be sealed with at least 3 in. of plain concrete on the ground cont"ct surface. Surfaces exposed to weathering should have at least a 2-in. protective layer of plain concrete. Structures subject to fire hazards should have a fire-resistant coating of concrete 1 in. thick for slabs and 2 to 4 in. thick for structural members. 

The nanocomposite surface phospholyration allows improving the nanocomposite structure, increases their activity in difleient liquid media thus increasing their influence on the material modified. The modification of coatings with nanocomposites obtained finally results in improving their fire-resistance and physical and chemical characteristics. 

An extremely fire-resistant coating material designed for spray applications to onshore and offshore oil and gas facilities has been introduced by Hempel s Marine Paints. The product, called ContraFlam 3810, is easy to apply and is particularly well-suited to the protection of structural steel work, walls, and floors. Another coating of a surface hardener/weather barrier material, such as Contraflam Topclad 3811, can then be applied followed by a color coat. 

These two technologies have created a new opportunity for the effective treatment of aluminised polyester and other laminating materials, in addition to polyimide foam, materials that will shrink when subjected to heat. A very thin layer of the new coatings may be sprayed on, leaving a protected surface that is flexible, very light weight, and fire resistant. 

A new approach to render fibre-reinforced rigid composite materials flame retardant is undertaken by the utilisation of complex fibrous-intumescent chars. The use of flame retarded cellulosics fabric, surface coated with an interactive intumescent as an additional reinforcement in an otherwise conventional structure has been studied. Thermal analysis has shown that when heated, all components decompose by chemically interactive mechanisms leading to a char-bonded stmcture and the residual mass of char formed is higher than expected above 450 °C, even in the case where polyester resins are present. Not only are greater fiactions of char formed above 450 °C but the chars formed are more resistant to oxidation than the respective components (resin, traditional fabric and coated cellulose). Thus composites comprising these various components will have significantly improved fire performance. 

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