Thermal insulation is the most replaced consumable in any vacuum furnace hot zone. Whether you need flexible graphite felt for wrapping cylindrical chambers or rigid CFC insulation boards for structural hot-zone walls, Expo Advanced Materials supplies both from New Delhi — cut to your drawings and shipped worldwide.
Graphite Felt — Specifications
Graphite felt is a flexible, fibrous carbon material used as the primary thermal insulation layer in vacuum and inert-atmosphere furnaces. Key specifications:
| Property | Standard Grade | High-Purity Grade |
|---|---|---|
| Density (g/cm³) | 0.08–0.12 | 0.10–0.15 |
| Max service temp (vacuum) | 2,200 °C | 2,800 °C |
| Available thickness | 6 mm – 50 mm | 6 mm – 50 mm |
| Roll width | Up to 1,200 mm | Up to 1,200 mm |
| Ash content | <200 ppm | <10 ppm (purified) |
Rigid CFC Insulation Boards — Specifications
Rigid boards are mechanically stable and maintain shape under gravity load, making them the preferred choice for structural hot-zone walls that must hold their geometry through thousands of thermal cycles.
- Density: 0.15–0.25 g/cm³
- Max service temperature: 2,800 °C in vacuum
- Flexural strength: 0.8–2.5 MPa (direction-dependent)
- Available size: up to 1,000 × 600 mm panels, thickness 20–100 mm
- Custom shapes: circles, cylinders, cones cut to your drawing
When to Use Felt vs Rigid Board
- Use graphite felt when you need a flexible wrap for cylindrical chambers, when easy field-replacement is a priority, or when cost per layer is the primary driver.
- Use rigid CFC boards when the insulation must be self-supporting (box furnace walls), when you need consistent wall thickness across thousands of cycles, or when your furnace OEM specifies rigid construction.
Custom Cutting and Fabrication
We supply insulation cut to your drawings — rectangular panels, discs, rings, and custom shapes. Felt is water-jet cut; rigid board is CNC milled to ±1 mm tolerance. Pre-drilled holes, notches, and keyed profiles available on request.
How to Order
Specify material type (felt or rigid), grade (standard or high-purity), thickness, dimensions, and quantity. For cut-to-shape orders, attach your drawing. We confirm pricing and lead time within 24 hours.