Carbon fiber insulation for high-temperature furnaces

KRECA FR is a high-purity insulation material that is ideal for use in high-temperature furnaces such as for metal heat treatment, ceramic sintering, and silicon ingot pulling.

About the product

KRECA FR, which has excellent insulating properties, is a product designed for use in furnaces with a high-temperature closed atmosphere. The graphitized carbon fiber insulation is manufactured by molding carbon fiber felt into specified shapes, such as boards, disks, and cylinders, using a small quantity of binder.

KUREHA Carbon Fiber KRECA FR Shapes

Main applications

  • Insulation for furnaces that manufacture multicrystalline silicon ingots
  • Insulation for furnaces that manufacture sapphire ingots or optical-fiber preforms
  • Insulation for monocrystalline silicon ingot-pulling furnaces
  • Insulation for sintering or heat-treating furnaces


  • Our insulation features superior thermal properties and excellent stability in a high-temperature atmosphere.
  • Our insulation is lightweight, yet solid enough to stand by itself. Complex machining is available as well.
  • Kureha handles the entire manufacturing process, which enables the quality to be closely controlled.
  • Various types of surface treatment are available to meet customer requirements.
  • Our insulation is less dusty than felt-formed insulation.

Installation advantages

  • Since KRECA FR is lightweight and easily machined into customers’ specified shapes, it is easy to handle or place, which reduces maintenance downtime.
  • We can support supply customers with insulation that is customized according to their needs in terms of thermal properties, surface treatments, product purity, and other requirements. Customers can freely design KRECA FR to suit their usage or conditions inside their furnaces.
  • We can provide surface treatments that ideally meet requirements, such as dust prevention or improving gas sealing.
  • The high purity of KRECA FR and its closely controlled production processes prevent contamination.

Standard product

Kureha has a regular stock of standard boards in a warehouse in Germany.

Grade: R202 (graphite foil on both sides)

Bulk density: 0.16 g/cm3


  • Width 1000 mm * length 1500 mm * thickness 20 mm
  • Width 1000 mm * length 1500 mm * thickness 30 mm
  • Width 1000 mm * length 1500 mm * thickness 40 mm


Types and Grades

KUREHA KRECA FR Carbon Fiber Specifications Types Grades

Typical physical properties and characteristics

KUREHA KRECA FR Carbon Fiber Specifications Typical Physical Properties CharacteristicsMeasuring method: Kureha standard test method. *At 1,500 degrees Celsius, test pieces with 50 mm thickness

Average thermal conductivity (in vac.)

KUREHA KRECA FR Carbon Fiber Specifications Average Thermal ConductivityUnder an atmosphere of 1.33Pa, 50 mm thick test pieces

Impurities contained

KUREHA KRECA FR Carbon Fiber Specifications Impurities Contained1 Assay of OS coating in R-200/0S weigh around 10% of the insulation itself in average. Ash content of "High-purity type" and "Ultra-high purity" will not be effected by the surface treatment. / Unit: ppm

Difference in oxidation between types of carbon fiber

KUREHA KRECA FR Carbon Fiber Specifications Difference in Oxidation between Types of Carbon FiberTemperatur range: from RT to 1,000 degrees Celsius (10 deg C/min) in air (200L/min)

Maximum sizes available

KUREHA KRECA FR Carbon Fiber Specifications Max Sizes AvailableMaximum available sizes differ depending on thicknesses. Please feel free to contact us about details.