Ceramic insulation and textiles are fibrous refractories or thermal insulation products that consist of:

• Ceramic fibers in bulk
• Cloth
• Batting
• Paper
• Rope 

Product Types

• Blankets consist of thick layers of woven or nonwoven fabric sheets.
• Woven materials are used for composite tooling and the formation of multi-dimensional structures.
• Nonwoven materials are shaped into mats of randomly oriented fibers.
• Ceramic fabric or cloth is made by weaving, knitting, braiding, or extrusion. Materials can also be needlepunched or formed from slurries (wet laid).
• Fibrous monofilaments or single-fiber threads are often used in reinforcement applications.
• Multi-fiber threads are used in sewing or stitching. Roving is made of tows, untwisted bundles of continuous filaments.
• Yarn is made of continuous, plied strands of natural or synthetic fibers.
• Heat-insulating rope is used to provide a thermal seal around doors or other openings in furnace walls.
• Sleeves or wraps are flexible, fibrous refractories for insulating pipes, tubes, ducts and other process components. 

Formats

• Woven ribbons
• Webbing
• Strapping
• Tape

Materials

• Alumina or aluminum-oxide is a popular, relatively inexpensive ceramic material with high hardness. Alumina has poor thermal shock resistance in comparison to silicon carbide, a green or black ceramic material that is used to prevent oxidation at very high temperatures in non-reducing atmospheres.
• Zirconia or zirconium oxide is more expensive than alumina, but is better suited for applications that require improved fracture-toughness and stiffness. Zirconia is extremely refractory and often contains additions of calcia, magnesia or yttria for the formation of cubic structures that minimize cracking and weakening during heating and cooling.
• Carbon is a non-metallic element with an extremely high sublimation temperature and a wide variety of crystalline structures. Boron fibers are available as monofilaments and used to provide structural reinforcement.
• Fused silica and quartz are common materials for ceramic insulation and textiles.

Some products include mineral wools such as slag wool, glass wool, or rock wool. Other products contain metal fiber additions.

Features

Ceramic insulation and textiles differ in terms of dimensions, properties, and features.

Dimensions

• Fiber denier
• Fabric weight
• Overall thickness
• Overall width or outer diameter (OD)
• Overall length

Properties

Use temperature, fabric strength, and breaking strength are important properties to consider. Thermal conductivity is the linear heat transfer per unit area through a material for a given applied temperature. Resistivity is the longitudinal electrical resistance in a uniform cross-section.

Special Features

• Flame retardant
• Chemical or fuel resistant
• Electrically conductive
• Electrically insulating
• Fireproof

Sound proofing or acoustic insulation materials are used to form a barrier between components and sources of noise or vibration. Often, foam materials are used to diffuse sound without causing a large degree of attenuation.

Hydrophilic and hydrophobic ceramic insulation and textiles are commonly available. Products with a UL 94 rating from conform to Flame Class 94V-0 standards from Underwriters Laboratories (UL).

Applications

Some products are designed for:

• Aerospace
• Automotive
• Marine
• Medical
• Transportation

Other products are suitable for chemical processing applications because of their ability to resist high temperatures and corrosive environments. Fibrous ceramics and refractories are used to fabricate electrical and electronic components such as insulators, igniters, and heating elements.

Ceramic insulation and textiles are also used in clothing such as outer garments that protect personnel from extreme thermal or chemical conditions. Cut-resistant and bullet proof materials, as well as products from original equipment manufacturers (OEM), are also available.

Standards

ASTM D3822 - Standard test method for tensile properties of single textile fibers.

BS EN 14759 - Shutters - acoustic insulation relative to airborne sound - expression of performance.

DEF STAN 02-806 - Requirements for ceramic products for thermal insulation applications: ceramic rope and ceramic blanket.

ISO DIS 16533 - Textiles - measurement of exothermic and endothermic properties of textiles under humidity change.

SAE AMS3679 - Insulation, thermal ceramic fiber.

References

Image Credits:

OMEGA Engineering, Inc. | Morgan Advanced Materials | Fuel Cells Etc.