Soft Graphite Felt – Flexible Refractory Insulating Material

High purity, high thermal stability.
Low thermal conductivity coefficient, no static electricity.
Easy cutting and machining.

Orderly placed soft graphite felt samples

Description

Soft graphite felt is a flexible insulating material for high temperature applications in inert or vacuum environments and is entirely made of carbon fibers. When used as an insulation material for high-temperature industrial furnaces, it can be bound and stitched with carbon ropes woven through special process. Due to its controlled internal structure and electrical conductivity, soft felts can also be used for energy storage like redox flow cells. Soft graphite felts are divided into PAN-based soft graphite felts, rayon based soft graphite felts, and soft felts for battery.

Features

Low thermal conductivity and static-free
Low specific heat
Allow for rapid heating and cooling of furnaces.
High temperature stability
In oxidizing environments up to 350 °C, in protective or vacuum environments up to about 3000 °C for graphite and 1000 °C for carbon.
Easy machining
Can be cut with scissors or blades and suitable for small bending radius.
Good surface properties
Not subject to all molten metals.
High purity
Low sulfur and ash contents.
High resistivity
Coupling in an inductive field only occurs above 12 kHz.

Category

PAN-Based Soft Graphite Felt
Rayon-Based Soft Graphite Felt
Soft Felt for Battery

PAN-Based Soft Graphite Felt

It is a refractory insulating material specially used in high temperature vacuum furnaces and inert gas furnaces with a working temperature of 3992 °F (2200 °C). It features high carbon content, good thermal resistance, low ash content, low sulfur content, good oxidization resistance, easy cutting and installation. If required, it can be purified to less than 10 ppm.

Table 1: Specification of PAN-Based Soft Graphite Felt
Model	Heat Treatment Temperature	Carbon Content	Density (g/cc)	Ash (ppm)	Available Thickness (mm)
CSF-1 Carbonized Soft Felts	1200 °C	≥ 97.5%	0.14–0.16	≤ 800	3/5/6/8/10/12.7
GSF-1 Graphite Soft Felts	2200 °C	≥ 99.5%	0.12–0.14	≤ 300	3/5/6/8/10/12.7
Notes: 1 MPa = 10.2 kgf/cm²; 1 W/m.k = 0.86 ^kcal/cm.h.°C These properties are typical values and not guaranteed.

Application

Redox flow cell
Microbial fuel cells or biofuel cells
Furnace body insulation and parts
Heat shields and heat sinks
Backing strips for welding
Cathodes for flow cell applications
Used on the reaction surface in the electrochemical process
Work as catalyst substrates in the electrochemical process
Glass blowing pads and plumber pads.
Ultralight furnace lamp wick
Automotive exhaust lining
Thermal insulation materials

Rayon-Based Soft Graphite Felt

Also known as viscose graphite felt, it is made of viscose based fibers (rayon) that are cured, shaped, and purified through secondary high-temperature processing, and pre-calcined at 4532 °F (2500 °C) to complete the graphitization of the material, making it suitable for working in environments above 2200 °C. It is a soft felt material with good flexibility and compressibility, and can be easily cut into different sizes.

Table 2: Specifications of Rayon-Based Soft Graphite Felt
Model	Heat Treatment Temperature	Carbon Content	Density (g/cc)	Ash (ppm)	Available Thickness (mm)
CSF-2 Carbonized Soft Felts	1200 °C	≥ 98.5%	0.10–0.14	≤ 500	3/5/6/8/10/12.7
GSF-2 Graphite Soft Felts	2200 °C	≥ 99.9%	0.08–0.14	≤ 300	3/5/6/8/10/12.7
Notes: 1 MPa = 10.2 kgf/cm²; 1 W/m.k = 0.86 ^kcal/cm.h.°C These properties are typical values and not guaranteed.

Application

Redox flow cell
Microbial fuel cells
Furnace body insulation and parts
Heat shields and heat sinks
Backing strips for welding
Cathodes for flow cell applications
Used on the reaction surface in the electrochemical process
Glass blowing pads and plumber pads.
Ultralight furnace lamp wick
Automotive exhaust lining
Thermal insulation materials

Soft Felt for Battery

It is specially used as quality electrode material for most energy storage systems like vanadium redox flow battery. It adopts special fibers and weave design, aiming to achieve high liquid absorption and electrical efficiency applications. As continuous production equipment is adopted, it has many unique properties including flat, smooth surface, uniform thickness and overall electrochemical uniformity. Therefore , as electrode, it has excellent performance in Vanadium Redox Flow Battery (VRFB) battery packs with low internal resistance, uelectrochemical quality with uniform activity, good corrosion resistance, slow decay after multiple cycles and high energy efficiency.

Table 3: Technical Data of Soft Felt for Battery
Model	Carbon Content	Ash Content	Bulk Density (g/cm³)	Specific Surface Area (m²/g)	Fiber Peeling Rate (μg/g)	Oxidation Rate (600 °C)	Porosity	Surface Resistivity (mΩ/cm³)	Internal Resistivity (mΩ)	Energy Efficiency
GBF-1	> 99%	< 0.2%	0.08–0.11	2.3–4.0	2.0–3.0	< 2.6%	85%–95%	0.165–0.193	15.3–26.7	Current Density 80 mA/cm²	Current Density 100 mA/cm²	Current Density 110 mA/cm²
GBF-1	> 99%	< 0.2%	0.08–0.11	2.3–4.0	2.0–3.0	< 2.6%	85%–95%	0.165–0.193	15.3–26.7	85.33%	84.22%	82.68%
Notes: 1 MPa = 10.2 kgf/cm²; 1 W/m.k = 0.86 ^kcal/cm.h.°C These properties are typical values and not guaranteed.

Table 4: Specifications of Soft Felt for Battery
Length (m)	10, 20, 50, 100
Width (m)	1.22, 1.35, 1.42, 1.45
Thickness (m)	2.2, 3.0, 3.6, 4.2, 4.8, 5.0, 5.6, 6.0, 7.0

Application

Electrode material for most energy storage systems like vanadium redox flow battery.