What is spunbond meltblown fabric and why it is in the face mask?
Spunbond Meltblown Spunbond fabric or SMS has become a hit for the last several month.
During the Coronavirus epidemic prevention and control period, masks and disposable clothing are in great demand.
Nonwoven materials have long been used in apparel, health care, engineering, for industrial purposes and for other consumer goods. Spunbond-Meltblown-Spunbond (SMS) is one such material made of Polypropylene. Here we introduce spunbond and meltblown techniques, as well as highlight the features of SMS and why it is used for face masks.
Spunbond
The spunbond process was first patented in 1940s and with further development has become popular with every decade. The technique itself includes fibers being spun and then directly being dispersed into a web by deflectors or air streams. They use no chemicals, and are thermo-bonded. Spunbonds have low weight, high strength, high air permeability, hydrophilic properties, and excellent wear and tear properties. Now spunbonds are much softer and comfortable than earlier, and weigh between 10 to 150 grams per square meter. They can be easily printed, laminated, dyed, or electrostatically charged.
Meltblown
spunbond technology and is the process whereby ultrafine filament
(micro-fibers) nonwovens can be produced at low costs. The technique includes
hot air being blown onto molten thermoplastic resin that is extruded through a
linear die containing hundreds of small holes, to form a fine fibered
self-bonded nonwoven web. Its key feature is that it is an extremely thin
fiber. As a result this material is often used for filters for air, liquids and
particles, or as absorbents in products such as wipes, oil absorbents,
incontinence products, and female hygiene, but can also be used in the
production of certain electronics, adhesives, and other apparel.
What is Lamination?
Nonwovens lamination is the process of bonding two or more layers, at least one of which is a nonwoven fabric, with the objective of obtaining improved strength, stability, sound insulation, appearance, or other properties. Although less expensive to manufacture, nonwoven fabrics tend to be weaker than woven ones, and the lamination process comes into play just when there is the need to strengthen this nonwoven material for a variety of uses.
The meltblown process came after
Nonwoven lamination creates breathable material that allow moisture to easily pass out of the garment, while preventing liquids from entering. The nonwoven composite material can also have an anti-microbial surface treatment to further enhances its protective properties. The outer layer of nonwoven fabric is soft to the touch, strong and durable.
The bonding is typically done with the use of adhesives (or heat) and pressure, making it possible to manufacture nonwovens products, equipped with a waterproof layer, that are breathable, soft, comfortable and suitable for printing.
Breathability was an issue with lamination in the early days, but the processes used today are capable of producing breathable, porous materials that maintain their waterproof properties.
When these are layered to form the SMS material the features can be combined together and the range of applications increases. Additionally, the combination of spunbond and meltblown materials means that the features of each can make up for the weaknesses of the other. For example, meltblowns have limited strength so can be combined with a spunbond to become a strong material, and likewise spunbonds can be elevated with the addition of meltblowns. These can even be combined to make a material which has a textile feeling to it. SMS has excellent physical properties as well as barrier qualities. Features include high tensile strength, softness, comfort, breathability, wearability, and is also lightweight. It also acts as a water-repellent, and a barrier against bacteria, blood and other liquids as well as gas/steam perspiration. Finally, it is also fine enough to serve as a disposable fabric.
Medical SMS Fabric is therefore suitable for medical and hygiene products such as diapers, protective wear, face masks, hospital gowns, wound care, caps, filtration fabrics, and much more.
Although SMS is more expensive than other materials such as non-layered materials, its unique features and specific design make it widely applicable for use. It can not only mimic the appearance, texture and strength of a woven fabric and can be as bulky as the thickest padding, but in combination with other materials also provides a spectrum of products with diverse properties. With the development of SMS it is thought that it will grow rapidly in the market of nonwovens and become more and more popular for various segments including apparel, geotextiles, furnishings, roofing as well as many others.
Most of hospital gowns, medical caps, medical masks, and shoe covers are manufactured using spunbond and meltblown techniques.
How Medical Masks Are Made
