The production principle of meltblown fabric
Meltblown fabric is a material that melts polymers at high temperatures and then sprays them into fibers under high pressure. These fibers rapidly cool and solidify in the air, forming a high-density, high-efficiency fiber network. This material not only has good filtering performance, but also is lightweight and breathable, making it very suitable for use in protective equipment such as masks.
The main raw materials for meltblown fabrics
The main raw material for meltblown fabric is polypropylene, commonly known as PP material. Currently, common meltblown fabric masks on the market use polypropylene meltblown fabric as the filtering material. The reason for choosing polypropylene as the main raw material is that it has good processing performance and cost advantages, and is relatively environmentally friendly.
In addition to polypropylene, meltblown fabrics can also be made of other materials such as polyester, nylon, linen, etc. However, compared to polypropylene, these materials have higher costs or poorer processing performance, making them less suitable for large-scale production.
Polypropylene is widely used in melt blown technology because it has the following advantages
1. The viscosity of the polymer can be controlled by using oxidants or peroxides in the extrusion process, or by mechanically shearing the extruder or controlling the working temperature to achieve thermal degradation, in order to regulate the viscosity of the melt.
2. The molecular weight distribution can be controlled by the melt blown non-woven fabric process, which requires a relatively narrow molecular weight distribution in order to produce uniform ultrafine fibers. By utilizing new catalytic technologies such as metallocene catalysts, polymers with extremely high melt index and narrow molecular weight distribution can be produced.
3. A higher melting point is sufficient for the heat resistance of polypropylene for most product applications, and it has a wide range of molten propylene. Scope, therefore, is very advantageous for the commonly used thermal bonding processing in non-woven fabric technology.
4. It is beneficial to produce ultrafine fibers. If the viscosity of polypropylene melt is low and the molecular weight distribution is narrow, it can be made into very fine fibers under the same energy consumption and stretching conditions in the melt blown process. Therefore, the common fiber diameter of polypropylene melt blown non-woven fabric is 2-5um, or even finer.
5. Due to the use of high-pressure hot air drawing in the melt spraying process, it is required to use polymers with higher melt index, which is beneficial for increasing production and reducing energy consumption. At present, the most widely used polypropylene chips have a melt index of 400-1200g/10min and a narrow molecular weight distribution to produce ultrafine fibers with the required linear density.
6. The polypropylene chips used in melt blown production and processing should have a high and uniform melt index, narrow molecular weight distribution, good melt blown processing characteristics, and uniform and stable chip quality to ensure the process stability of melt blown nonwoven materials.
Precautions for the production of meltblown fabric
In the process of making meltblown fabric, the following points should be noted:
1. The material selection should be sufficiently pure: As the meltblown fabric needs to bear the filtering effect, it is necessary to choose materials that are sufficiently pure when selecting raw materials. If there are too many impurities, it will affect the filtration efficiency of the meltblown fabric.
2. Control processing temperature and pressure: The processing temperature and pressure should be set according to the type of raw material to ensure the effectiveness of fiber forming.
3. Ensuring hygiene in the production environment: As meltblown fabric is used for producing protective equipment such as masks, hygiene in the production environment is very important. It is necessary to ensure the cleanliness of the production workshop to avoid contaminating the products.
Dongguan Liansheng Non woven Technology Co., Ltd. was established in May 2020. It is a large-scale non-woven fabric production enterprise integrating research and development, production, and sales. It can produce various colors of PP spunbond non-woven fabrics with a width of less than 3.2 meters from 9 grams to 300 grams.
Post time: Nov-08-2024