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May 11 - May 17, 2015

What are the performance distinctions among various types of intumescent coatings (for example, water-based, solvent-based, epoxies and methacrylates)?

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From Philip Kabza of SpecGuy Specifications Consultants on May 21, 2015:
Industry specifications refer to two different types of products that serve two different purposes but are frequently confused. Fire-retardant intumescent paints comply with a Class A or B flame-spread index when tested according to ASTM E 84 (or NFPA 255 and UL 723). They affect the surface burning characteristics of the surface on which they are applied. They are not fire-resistive coatings. Mastic and intumescent fire-resistive coatings (MIFRC) are fireproofing; they are used to increase the fire resistance of structural components to comply with the hourly fire resistances established by the building code. They are tested according to ASTM E 119 or UL 263. They may also be tested as fire-retardant coatings and serve that purpose. To keep the two types of products straight, look at the tests. If a design requires an hourly rating, it requires ASTM E 119 and fire-resistance; if the design requires just a Class A, B, or C flame-spread rating, it requires ASTM E 84 and fire-retardance.

From ramoo puru of tiger coatings on May 19, 2015:
Intumescent coatings usually are not restricted to water-based or solvent-based. They are more restricted to protection of a specific substrate ( wood / timber or structural steel) and time. Usually, structural steel requires fire protection provided by a fire protection-based coating. Intumescent coatings provide reliable fire protection and decoration of steelwork. They are rated according to how much time they can protect the steel, such as 30, 60, 90 and 120 minutes of fire protection for beams, columns, hollow sections.
      Intumescent coatings provide an appearance similar to that of a paint finish. At ambient temperatures, they remain stable. However, in the unlikely event of a fire situation, the increase in temperature causes a chemical reaction. The intumescent coating expands to many times its original thickness. This provides an insulating foam-like coating or "char" that protects the substrate. The intumescent coating is designed to insulate the steel and thereby to prevent the temperature of the steel from rising to a critical point at which structural failure becomes possible. Timber structures are more susceptible to the surface spread of flame and heat propagation. Intumescent coatings are designed to reduce heat propagation, and reduce the spread of flame. The expansion process is caused by the interaction of several precisely formulated components. Typically, the intumescent process is as follows.  As heat is applied, the chemical reaction begins. The heat begins to soften the polymeric binder, which then also causes an organic acid to be released. As the blowing agent decomposes, gas is produced, which swells the molten mixture Finally, the foamed char solidifies, through a cross-linking reaction, to maintain the insulation.

From Warren Brand of Chicago Corrosion Group on May 14, 2015:
I keep waiting for someone to answer because I am interested in the responses. But I'll take a shot. The short answer is, I don't know. However, my understanding of intumescents is that the performance drives the material so that, as I understand it, they should all perform equally well in order to meet various industry standards, such as ISO 22899-1:2007 for jet fire protection. That is, when NASA puts out to bid for a lunar lander, the specification is performance-based. So, I would assume that the performance of all of the materials, would, by necessity, need to be the same to meet the various industry performance standards for pooling fire and jet fire (I don't know the standards off the top of my head). I would also surmise that the main differences between the materials would be in application and, perhaps, performance in terms of  longevity, UV-resistance, corrosion resistance, etc. But, as pertains to performance as a PFP technology, I would suspect they would be similar or the same. Am I close?

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Tagged categories: Asia Pacific; Coatings Technology; EMEA (Europe, Middle East and Africa); Intumescent; Latin America; North America; Passive Fire Protection

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