Non Woven Fabric Processing Technology-Meltblowing(Part 2)

2. Blowing and stretching

During the production process, the heated high-pressure air is blown out at a very high speed from the stretching air duct, and the thin stream of melt extruded from the spinneret is stretched at a high speed to be ejected into ultra-fine short fibers. Therefore, the stretching The speed and temperature of the airflow have a great influence on the forming and drawing of meltblown staple fibers. The higher the drawing air velocity, the smaller the diameter of the short fibers blown out, but the high velocity will affect the collection of fibers. The temperature of the stretching hot air should not be too low, and it should be able to keep the melt in a viscous flow state. Our company provides non woven polyester.

3. Fabric forming

The ultra-fine short fiber obtained by hot air blowing and stretching is blown and cooled, and then blown onto a collecting device such as a net curtain or roller with mesh. The lower part of the net curtain or the inside of the porous roller is sucked by vacuum The device forms a negative pressure, and the fibers are collected on a condensed mesh curtain or a porous roller, relying on self-bonding or heating to form a type. The vertical distance from the outlet of the spinneret of the machine head to the surface of the condensed screen or porous roller is called the receiving distance of the web. The receiving distance of the web has a greater impact on the air permeability and strength of the nonwoven product, and also Affect the draw ratio of short fibers and the laying range of fibers. The receiving distance of the fiber web increases, the time for the sprayed short fibers to reach the surface of the collection device is prolonged, the number of fibers collected at the same position is reduced, and the fiber network structure is more fluffy, so the pore size and porosity of the nonwoven fabric become larger, and the air permeability The performance becomes better, the filtering effect is improved, and the hand feels fluffy, but the tensile strength and bursting strength of the non-woven fabric are reduced. The receiving distance is reduced, the cooling effect of the fibers is poor, the fibers are easy to bond, and become a crimped agglomeration state, thus reducing the bulkiness of the fiber web. From the outside, according to the influence of the receiving distance on the structure of the fiber web, if the process of continuously changing the receiving distance is adopted during the forming of the web, a non-woven fabric with a density gradient can be produced, which can be used as a filter element material for graded filtration.

The above information is provided by paint cover felt factory.