Ceramic fiber blankets are refractory and insulating materials produced by melting raw materials at temperatures above 2000°C, forming fibers through either a "blown" or "spun" process, and then reinforcing them with double-side needling. The resulting product is referred to as a "blown blanket" or "spun blanket," respectively. The two types differ primarily in fiber structure, performance, and suitable applications, as outlined below:
01 Fiber Diameter
Spun blanket fibers are coarser, typically 3.0–5.0 µm in diameter.
Blown blanket fibers are finer, generally 2.0–3.0 µm in diameter.
02 Fiber Length
Spun fibers are longer, usually 150–250 mm.
Blown fibers are shorter, typically 100–200 mm.
03 Thermal Conductivity
Due to their finer fibers and denser packing, blown blankets usually have lower thermal conductivity than spun blankets, providing better insulation at the same thickness.
04 Tensile & Flexural Strength
Spun blankets, with their thicker and longer fibers, exhibit stronger internal bonding, significantly outperforming blown blankets in both tensile and flexural strength, and offering higher mechanical durability.
05 Application in Ceramic Fiber Modules
Ceramic fiber modules are made by folding and compressing ceramic fiber blankets, and their quality directly determines the overall performance of the furnace lining.
The coarse, long fibers of spun blankets are highly flexible and resistant to breakage or tearing during folding, allowing them to be compressed into tightly structured, high-strength modules.
The fine, short fibers of blown blankets are more prone to fragmentation or damage during folding, making them less suitable for module manufacturing.
06 Installation Methods & Suitable Applications
In layered insulation structures (such as those in heat recovery boilers and other thermal equipment), spun blankets are generally recommended. Their superior toughness and mechanical strength enable them to better withstand installation stresses and ensure long-term stability of the insulation structure.
Key Conclusion:
Spun blankets offer better mechanical strength, formability, and durability, making them suitable for module construction and environments with higher mechanical stress.
Blown blankets, with their lower thermal conductivity, hold an advantage in layered applications where ultimate thermal insulation is the priority.
Final selection should be based on a comprehensive evaluation of the specific application environment and performance requirements.
