Although it’s common knowledge that asbestos poses numerous health risks, it has been difficult to find one fiber that covers the same temperature ranges and offers the same level of chemical resistance. These inherent characteristics established asbestos as the insulation of choice for engines, boilers, and piping, from the 1800s through the 1980s. As serious health risks were uncovered, asbestos was banned and the search for risk-free alternatives began.
Because no one single material adequately covers the full range of temperatures, from Arctic lows to the high temperatures experienced in engines of all types, it was necessary to develop a variety of materials to cover requirements for insulation purposes. Firwin has never used asbestos, and we’re dedicated to manufacturing the right material combination for a given project.
Below, we offer descriptions of several common alternative materials, and the appropriate applications for each.
1. Cellular glass. Impermeable to moisture, cellular glass is non-combustible and can’t burn. This material is often used in cryogenic insulation and some industrial applications.
2. Polystyrene and polyurethane. For low temperatures through 250 degrees F, foams, polystyrene, and polyurethane can often provide the solution. Environmental disposal must be taken into consideration.
3. Cellulose insulation. Often used in house insulation, cellulose insulation must be treated with fire retardants before use. When wet, it takes considerably longer to dry than fiberglass, and is not suitable for high temperature insulation.
4. Fiber insulation. Fiber insulation is made from melted minerals, which are then extruded to form fibers. These fibers can be processed into batts, blankets, boards, and preforms, as required by a particular application. Fibers used by reputable manufacturers feature a fiber diameter and length well in excess of ACGIH requirements. Because fibrous, non-organic materials can cause temporary discomfort and irritation, protective clothing should be worn. Types of fiber insulation include:
- Fiberglass. Fiberglass is the preferred insulation for temperatures up to 1100 degrees F. In accordance with ACGIH requirements, the fibers are long and they dissolve in body fluids. House and building applications, boilers, and engine exhausts all benefit from various forms of fiberglass insulation.
- Mineral wool and basalt wool. Made from melted volcanic rock and extruded into fiber, spun mineral wool is then chopped into separate fiber lengths and manufactured into blankets and boards. With a thermosetting resin to bind the fibers, these materials cover temperatures up to 1100 degrees F, much like fiberglass.
- Ceramic wool. Ceramic wool insulation is suitable for insulating equipment at temperatures up to 2400 degrees F. Ceramic wool materials also exhibit better thermal conductivity characteristics than fiberglass.
As will all insulation materials, care must be taken in both selecting and using the above materials. Additional materials for higher temperature applications are also available—as is green insulation. Please check in next week to learn about the distinct advantages of going green.