meltblown

Meltblown is a manufacturing process to produce fine-fiber nonwoven fabrics from thermoplastic polymers. In a typical meltblown operation, molten polymer is extruded through a row of small nozzles (or orifices) into a high-velocity airstream. The hot air attenuates the polymer into micro-scale fibers that are collected by a moving screen or belt to form a web. The resulting fabric has a very small fiber diameter and a highly porous, low-density structure.

Polypropylene is the most common polymer for meltblown fabrics because of low cost, chemical resistance, and suitable rheology. Other polymers, including polyethylene, polyethylene terephthalate, polyamides, and certain biobased polymers, are used for specialized applications. Fiber diameters typically range from about 0.5 to several micrometers, yielding high surface area and fine pore structure. Basis weights are usually low, often in the range of 5 to 100 g/m2, with higher porosity than traditional textiles. The fabrics generally have limited mechanical strength and are used in layered products.

Production requires specialized equipment: a polymer melt extruder and die, a high-speed hot-air system to attenuate fibers, and a collector. Key parameters include melt temperature, air temperature and velocity, line speed, die geometry, and fiber collection distance; precise control influences fiber diameter uniformity and web integrity.

Meltblown nonwovens are widely used for filtration and absorption applications, including air and liquid filtration, industrial filters, and medical products. They are frequently bonded with other nonwovens (for example, in SMS structures where meltblown is sandwiched between spunbond layers) to improve strength and handle. The process is a major component of modern filtration media and disposable garments.