A New Carbon Fiber Soft Felt Production Line of SGL Carbon is About to be Put Into Operation

 

According to the latest news provided by SGL Carbon on September 7, the company is currently expanding and modernizing its carbon fiber soft felt production. In the past two years, SGL Carbon has invested millions of euros in a new carbonization facility at its Meitingen plant near Augsburg, Germany, which is now in normal operation.

 

SGL Carbon’s carbon fiber soft felt, branded SIGRATHERM®, is mainly used as a particularly high-quality insulation material in resistance-heated and induction-heated vacuum furnaces and inert gas atmosphere furnaces. Its application areas include ceramic sintering processes in the semiconductor, solar industry and hard metal industry.

 

In addition, carbon fiber soft felt can also be used as battery felt (SIGRACELL® series products) in stationary energy storage and fuel cell systems, and as a precursor material for the production of carbon-based friction linings for dual clutch transmissions and similar applications in the automotive and aerospace industries.

“With this expansion, we are further extending our leading position as a quality and technology leader and thus can expand our product range in line with market developments. The capacity expansion not only enables us to produce larger quantities of carbon fiber felts, but also to drive the development of new products more vigorously than before.” Karl Hingst, Director of the Fiber Materials Product Group at SGL Carbon, said.

 

As a leading graphite manufacturer, SGL Carbon not only has advanced equipment and technology, but is also the first company in the world to produce carbon fiber soft felts in a continuous high-temperature process.

 

SIGRATHERM® Carbon Fiber Soft Felt from SGL Carbon

 

SIGRATHERM® soft felt is a flexible insulation material for high-temperature applications in an inert or vacuum environment, consisting entirely of carbon fibers. The stability of the carbon fiber felt is determined in the first production step (needling process) and continues throughout all subsequent high-temperature heat treatment processes.

 

In addition, the soft felt can be used for energy storage such as redox flow batteries due to its controllable internal structure and electrical conductivity. At present, SGL carbon’s SIGRATHERM brand carbon fiber soft felt is mainly used for insulation applications, while for energy storage applications, the company has specially developed so-called battery felts, which are available under the SIGRACELL® brand.

 

 

The main advantages of carbon fiber soft felt include 4 aspects: very low thermal conductivity at the highest temperature; low heat capacity; suitable for very high temperatures; composed of pure carbon fiber,

 

The basic material for the production of carbon fiber soft felt is felt made of needle-punched fibers. They are processed into carbon fiber soft felt by heat treatment at 800-1,000°C. If these felts are treated at higher temperatures above 2,000°C, the carbon fibers will increasingly take on a graphite-like structure, forming so-called “graphite soft felt”. The manufacturing process of carbon fiber soft felt is shown in the figure below: