What is melt blown non-woven fabric
Melt blown non-woven fabric is a new type of textile material made from high polymer materials through processes such as raw material preparation, high-temperature melting, spray molding, cooling and solidification. Compared with traditional needle punched non-woven fabrics, melt blown non-woven fabrics have a finer and more uniform fiber structure, as well as certain breathability and water resistance, making them an important development direction in the field of textile materials.
The characteristics of melt blown non-woven fabric
1. Efficient filtration performance, which can effectively block the spread of harmful substances such as particles, bacteria, viruses, etc;
2. Soft and comfortable, with good breathability, comfortable to wear, and no allergic reactions;
3. Wear resistant, waterproof and oil resistant, with a long service life and excellent durability;
4. Easy to process, capable of cutting, sewing, hot pressing, laminating and other treatments according to different needs.
The application of melt blown non-woven fabric
Melt blown non-woven fabric has a wide range of application prospects, and has been explored in fields such as healthcare, hygiene, and home furnishings. The main application areas are as follows:
1. Medical and Health: Melt blown non-woven fabric is widely used in the production of protective equipment such as masks, surgical gowns, and isolation gowns, which can effectively isolate bacteria and viruses, ensuring the safety of medical staff and patients.
2. Home Furnishings: Melt blown non-woven fabric is used to make daily necessities such as wet wipes, facial cleansers, and washcloths with good water absorption, water resistance, and not easy to shed hair, improving the user experience.
3. Filter material: Melt blown non-woven fabric can be made into filter materials for air, water, and oil, which can effectively remove particles in the air and reduce pollutant emissions. It can also be used in fields such as mechanical filtration and drinking water filtration.
Melt blown non-woven fabric is a good insulation material
Melt blown nonwoven fabric has a large specific surface area and small voids (pore size ≤ 20) μ m) High porosity (≥ 75%) and other characteristics. If the average diameter is 3 μ The specific surface area of the melt blown nonwoven fabric fibers, equivalent to an average fiber density of 0.0638 dtex (with a fiber size of 0.058 denier), reaches 14617 cm2/g, while the average diameter is 15.3 μ The specific surface area of spunbond nonwoven fibers, which is equivalent to an average fiber density of 1.65 dtex (with a fiber size of 1.5), is only 2883 cm2/g.
Due to the much smaller thermal conductivity of air compared to ordinary fibers, the air in the pores of melt blown nonwoven fabric reduces its thermal conductivity. The heat loss transmitted through the fiber material of melt blown nonwoven fabric is minimal, and the static air layer on the surface of countless ultrafine fibers prevents heat exchange caused by the flow of air, making it have good insulation and warming effects.
Polypropylene (PP) fiber is a type of existing fiber material with a very low thermal conductivity. The melt blown thermal insulation floc made of PP fiber after special treatment has a thermal insulation performance 1.5 times that of down and 15 times that of ordinary thermal insulation cotton. Especially suitable for making skiing clothes, mountaineering clothes, bedding, sleeping bags, thermal underwear, gloves, shoes, etc. Products with a quantitative range of 65-200g/m2 have been used to make warm clothing for soldiers in cold regions.
How to improve the filtration efficiency of melt blown non-woven fabric
Melt blown non-woven fabric, as the core material of medical masks, its filtration efficiency directly affects the protective effect of the mask. There are many factors that affect the filtration performance of melt blown non-woven fabrics, such as fiber linear density, fiber mesh structure, thickness, and density. As an air filtering material for masks, if the material is too tight, the pores are too small, and the breathing resistance is too high, the user cannot inhale air smoothly, and the mask loses its value for use. This requires that filter materials not only improve their filtration efficiency, but also minimize their respiratory resistance, which is a contradiction between respiratory resistance and filtration efficiency. The electrostatic electret treatment process is a good way to solve the contradiction between respiratory resistance and filtration efficiency.
Mechanical barrier
The average fiber diameter of polypropylene melt blown fabric is 2-5 μ m. Particle size greater than 5 in the air μ The droplets of m can be blocked by meltblown cloth; When the diameter of the fine dust is less than 3 μ At m, due to the random arrangement of fibers and interlayers in the melt blown fabric, a fiber filter layer with multiple curved channels is formed. When particles pass through various types of curved channels or paths, fine dust is adsorbed on the surface of the fibers by mechanical filtering van der Waals forces; When the particle size and airflow velocity are both large, the airflow approaches the filter material and flows around due to obstruction, while the particles detach from the streamline due to inertia and collide directly with the fibers to be captured; When the particle size is small and the flow rate is low, the particles diffuse due to Brownian motion and collide with the fibers to be captured.
Electrostatic adsorption
Electrostatic adsorption refers to the capture of particles by the Coulomb force of the charged fiber (electret) when the fibers of the filter material are charged. When dust, bacteria, viruses, and other particles pass through the filtering material, electrostatic force not only effectively attracts charged particles, but also captures induced polarized neutral particles through electrostatic induction effect. As the electrostatic potential increases, the electrostatic adsorption effect becomes stronger.
Post time: Apr-08-2024