Since twenty-first Century, the development of melt blown nonwovens technology in the world is developing rapidly.
Hills company and Nordson company have developed the dual component melt spray technology earlier, including skin core, parallel type, triangle and so on. Usually the fiber size is close to 2. The number of holes in the melt spray component can reach 100 holes per inch, and the extrusion quantity of each hole can reach 0.5g/ points.
Leather core type: it can make the nonwoven fabric feel soft and can be made into concentric, eccentric and heteromorphic products. Generally cheap material to make the core, expensive, special or required properties of the polymer as the outer skin layer, such as the core of polypropylene, the outer skin is nylon to make the fiber hygroscopic, the core is polypropylene, the outer skin is a low melting point polyethylene or modified polypropylene, modified polyester, etc. For carbon black conductive fibers, the conductive core is wrapped in it.
Parallel type: it can make non-woven fabric with good elasticity, usually made of two different polymers, or different viscosity of the same kind of polymer made of parallel double component fibers, using different thermal shrinkage of different polymers can be made into spiral curl fiber. For example, 3M has developed nonwovens for the melt blown PET/PP double component fiber, which makes the nonwovens with excellent elasticity because of the different shrinkage and spiral curl.