What are the manufacturing processes for aluminosilicate ceramic insulation wool?

　　According to their manufacturing processes, they are classified as spun-bonded cotton and spun‑fiber cotton. These materials are produced by calcining coal gangue, coke‑derived alumina, and other raw materials, followed by high‑temperature melting. The molten material is then spun into fibers or blown into fibers, after which specialized equipment compacts the loose fibers into a cotton web of a specified thickness.

　　Due to the high brittleness of high‑alumina refractory materials, only the blow‑in process is employed; for zirconia‑alumina fiber blankets, only the centrifugal spinning process is used. Relatively speaking, the centrifugal spinning process yields a higher output. There are two primary forming processes for producing aluminosilicate ceramic fibers: the blow‑in process and the centrifugal spinning process. What are the key differences between these two methods, and what are their respective development trends?

　　History

　　From a historical perspective, the blow‑spinning process was the first to be developed; however, its per‑line production capacity is relatively low, with annual output typically ranging from 1,000 to 1,500 tons. To enhance production efficiency, continuous efforts have been made to explore and refine new manufacturing processes for aluminosilicate ceramic fibers. Subsequently, the more advanced centrifugal spinning process was introduced, which boasts a per‑line production capacity two to four times that of the blow‑spinning method. A single centrifugal spinning line can achieve an annual output of up to 6,000 tons.

　　Application

　　Alumina–silica ceramic fiber wool produced by the centrifugal spinning process has been widely recognized by manufacturers and customers across most industries. In China, nearly all newly built alumina–silica ceramic fiber production lines over the past decade have adopted this centrifugal spinning method. Spray‑blown alumina–silica ceramic fiber wool also boasts unique applications; for instance, when the fibers need to be shredded and processed into secondary products—such as vacuum‑formed items—the finer texture of spray‑blown fibers facilitates more thorough blending with other materials, making it particularly favored.

　　Development trend

　　Looking ahead, the total domestic production of aluminosilicate ceramic fibers is expected to continue growing, with the spun‑fiber process remaining the dominant manufacturing method. By contrast, the production scale and market share of blown‑type aluminosilicate ceramic fiber wool are likely to decline gradually. The blow‑up process is better suited to smaller‑scale operations, particularly those that entered the market with relatively modest initial investments. Meanwhile, competition in China’s ceramic fiber market for the spun‑fiber process will intensify, which is undoubtedly beneficial for consumers, as they can access more and higher‑quality products at lower costs. This development also bodes well for related industries involved in thermal‑energy applications, especially in terms of energy conservation and efficiency improvements across industrial processes.

　　Alumina–silicate ceramic fibers produced by the spun‑fiber and blow‑in processes each have their own advantages; customers should select the method best suited to their specific application, leveraging its strengths while mitigating its limitations, in order to achieve optimal performance. At present, spun‑fiber blankets are far more widely applicable than blow‑in blankets.