The melt blown process is a nonwoven manufacturing system involving direct conversion of a polymer into continuous filaments, integrated with the conversion of the filaments into a random laid nonwoven fabric. First developments in this field of technology in the industrial area started around 1945. The general process description is similar to the spunlaid process, but in detail, both types of processes are quite different. Using the melt blown technology, the spun filaments are accelerated by means of hot, fast-flowing air that is directly blown onto a moving substrate, creating a self-bonded web. Figs 5.5–5.8 show principles and sketches of the different melt blown technologies. The hot air temperature is close to the used melt temperature. The achieved filament diameter is one magnitude lower compared to the spunlaid process, 1–5 μm. The calculated filament speed out of throughput and measured filament diameter is resulting in filament speed higher than sonic speed. Since the used air geometries are not suitable to create supersonic speed, the air speed cannot the single source of forces for the downsizing of the filaments.