In our last installment of Choosing the Right Material for Your Insulation Blankets, we went over basic insulation materials. This time around, let’s review more in-depth and discuss outer and inner covers. We have a lot of ground to cover, so we will break down the materials into three categories of usage: Outer Covers, Inner Liners, and those than can do both.
- Aluminized Fiberglass – Also known as Mirrored Fiberglass, it offers great aesthetic qualities and is used in place of silicone and PTFE where aesthetics are important. It has an advantage over fiberglass and PTFE—even when the aluminum coating breaks down at 450°F (230°C), the fiberglass substrate maintains its integrity up to 1000°F (538°C).
- Heavy Duty Silicone – Often used in more severe outdoor applications when resistance to wear and tear is necessary. It is flexible, flame retardant and water, oil, mold, and chemical resistant. Has a temperature range of -67°F (-55°C) to 500°F (260°C).
- Stainless Steel Laminate Fiberglass – Quite expensive but is perfect where high levels of oil, chemical, and fire resistance are required. Unlike aluminized fiberglass, when its coating breaks down the laminate foil retains its integrity and can continue to act as a fluid barrier.
- Stainless Steel Mesh 304 – This common inner liner is used in most standard situations and has a temperature range up to 1200°F (649°C).
- Stainless Steel Mesh 309, 316 – 309 offers a higher temperature range of 1800°F (982°C), while 316 is made specifically with marine environments in mind.
- Stainless Steel Mesh Foil with Mesh Cover – Roughly, the same as 309 but offers a fluid barrier.
- Stainless Steel Mesh Inconel – This top-of-the-line liner offers the highest temperature range (2300°F/1260°C) but is quite expensive.
Outer Cover and Inner Liner
- Silicone Impregnated Fiberglass – A standard outer cover that is also used as an inner liner for applications < 500°F where a fluid barrier or insulation fiber containment is desired.
- PTFE Coated Fiberglass – Interchangeable with and used in place of silicone in paint, food, and other chemical applications thanks to its broader chemical resistance. Both are flexible, flame retardant, water, oil, and mold resistant.
- PVC – If you do not have a need for a high temperature rating, this is a good low-cost alternative to silicon and PTFE.
- Fiberglass HT – A non-coated fabric used both as an outer cover and inner liner in high temperature conditions of >500°F/260°C. Also good for containing insulation fibers.
- Silica – Another multi-use, non-coated fabric, Silica is perfect for extreme high temperature conditions of >1300°F/982°C. It is more expensive but is also fireproof, mold resistant, and good for containing insulation fibers.
Choosing the correct insulation blanket material makeup can be daunting—you need industry experts at a company like Firwin to recommend the right combination for your application.