Why Is Meltblown Non-woven Fabric the Heart of N95 Masks?

What is meltblown non-woven fabric?

Meltblown fabric is primarily made from polypropylene, with fiber diameters ranging from 1 to 5 microns. The unique capillary structure of the ultra-fine fibers increases the quantity and surface area of fibers per unit area, resulting in excellent filtering, shielding, insulation, and oil absorption properties. It is suitable for use in air and liquid filtering materials, isolation materials, absorbent materials, mask materials, thermal insulation materials, oil-absorbent materials, and wiping cloths.

The manufacturing process for meltblown non-woven fabric is as follows: polymer feeding - melting and extruding - fiber formation - fiber cooling - collection and reinforcement into a cloth.

Applications of meltblown non-woven fabric

Medical and sanitation fabrics

Surgical gowns, protective clothing, disinfection wrap, masks, diapers, feminine hygiene pads, etc.

Home decoration fabrics

Wall coverings, tablecloths, bed sheets, bedspreads, etc.

Clothing fabrics

Lining, fusible interlining, padding, shaping cotton, various synthetic leather bottom cloth, etc.

Industrial fabrics

Filtering materials, insulation materials, cement packaging bags, geotextiles, covering fabrics, etc.

Agricultural fabrics 

Crop protection fabrics, raising seedlings fabrics, irrigation fabrics, thermal insulation screens, etc.

Others

Space cotton, insulation and soundproofing materials, oil-absorbing felt, cigarette filter tips, tea bags, etc.

The importance of meltblown non-woven fabric

Medical surgical masks and N95 masks usually use a multi-layer structure, abbreviated as SMS structure: single layer spunbond layer (S) on both sides of the outer and inner layers; and a meltblown layer (M) in the middle, generally single or multi-layered.

Flat masks are generally made of PP spunbond/non-woven fabric + meltblown non-woven fabric + PP spunbond/non-woven fabric, with the option to use short fibers for the inner layer to improve skin comfort. Cup-shaped masks are generally made of PET polyester needle-punched cotton + meltblown non-woven fabric + needle-punched cotton or PP spunbond/non-woven fabric.

The outer layer is a non-woven fabric treated for waterproofing and used primarily for blocking droplets from patients; the middle meltblown layer is a specially treated meltblown non-woven fabric with excellent filtering, shielding, insulation, and oil absorption properties, which is an important raw material for producing masks; and the inner layer is a common non-woven fabric.

Although the spunbond layer (S) and meltblown layer (M) of masks are both non-woven fabrics made from polypropylene, their manufacturing processes differ. The fibers in the spunbond layers on both sides are thicker, at around 20 microns, while the fibers in the meltblown layer are only 2 microns and made from a polypropylene material known as high melt index fiber.