What is the difference between spunbond and meltblown nonwoven?

Spunbond and meltblown are both techniques used in the production of nonwoven fabrics, which are widely used in various industries including healthcare, automotive, and construction. Here are the key differences between spunbond and meltblown nonwovens:

Production Process:
Spunbond: Spunbond nonwovens are produced by extruding continuous filaments of a thermoplastic polymer (like polypropylene) through a spinneret and then laying them onto a conveyor belt to form a web. The web is then bonded together by heat and/or pressure.
Meltblown: Meltblown nonwovens are made using a similar process, where polymer pellets are melted and extruded through a die. The extruded filaments are then blown by hot air onto a conveyor belt or a drum to form a fine fiber web. The fibers are typically finer than those produced by spunbond methods.

Fiber Diameter and Structure:
Spunbond: Spunbond fibers are typically thicker and have a more open structure compared to meltblown fibers.
Meltblown: Meltblown fibers are much finer and have a random orientation, creating a very thin, dense web. This fine fiber structure gives meltblown fabrics excellent filtration properties, making them suitable for applications like surgical masks and air filters.

Properties and Applications:
Spunbond: Spunbond nonwovens are known for their strength, durability, and breathability. They are used in applications such as hygiene products (like diapers and feminine hygiene products), geotextiles, agriculture (for crop protection), and furniture upholstery.
Meltblown: Meltblown nonwovens are highly efficient in filtration due to their fine fiber diameter and random fiber orientation. They are used extensively in medical face masks, respirators (N95 masks), surgical gowns, and other filtration applications.

Cost and Production Efficiency:
Spunbond: Spunbond fabrics are generally less expensive to produce compared to meltblown fabrics.
Meltblown: Meltblown fabrics require more precise manufacturing processes and typically have higher production costs due to the complexity of creating the fine fibers.

While both spunbond and meltblown nonwovens are used in various industries, meltblown fabrics are particularly valued for their superior filtration properties, which are crucial in applications requiring high levels of filtration efficiency such as medical and industrial settings.