The outbreak of the new epidemic has led to a sharp increase in the demand for masks and disposable medical supplies. While they have made positive contributions to epidemic prevention and control, they have also brought great pressure to environmental protection. Therefore, the development of fully biodegradable melt spun non woven has become the focus of social attention. This paper briefly describes the production process and performance characteristics of polylactic acid melt spun non woven fabric.
The technological process of polylactic acid spunbonded non woven is: polylactic acid slicing → screw extruder → melt filter → metering pump → spinneret → cooling and blowing → air draft → mesh laying → hot rolling reinforcement into cloth (or spunlace, needle reinforcement) → winding → finished product.
The strength of nonwovens produced by filament direct netting is much higher than that of nonwovens produced by other methods. In order to meet the needs of different fields, this material can also be processed into composite products.
Due to the excellent properties of polylactic acid, the spunbonded non woven has good weather resistance and strength retention at room temperature; In the natural environment such as soil, sea water and sludge, it can be completely decomposed into water and carbon dioxide after a period of time. Its strength is higher than that of PP spunbonded fabric and similar to that of PET spunbonded fabric; Hydrophilic property is better than PP, PET spunbonded fabric; Good elasticity, good handle and drapability, high strength, not easy to burn and smoke.
Polylactic acid melt blowing method non woven is to melt polylactic acid slices, and then through the injection of high-speed high-temperature air flow, the melt trickle is extremely stretched to form ultra-fine short fibers, which then gather on the roller or mesh curtain to form a fiber web, and finally form a cloth through self-adhesive cooperation. The process flow is: PLA slicing → drying → screw extruder melting → filter → metering pump → melt blowing die head → melt trickle stretching → fiber cooling → mesh laying and receiving → bonding into cloth → winding.
It has many characteristics, mainly including the following three points:
(1) Biodegradability in line with the concept of sustainable development;
(2) At room temperature, it has good weather resistance and good strength;
(3) Because of the melt blown technology, it has very fine fiber, many pores and small size, and has obvious advantages in filtration, bacteria inhibition, adsorption and so on.
Polylactic acid is the most promising biodegradable material at present. When it is combined with melt spun non woven fabric with short process flow, high efficiency and convenient variety development, and the production technology and cost are tackled, the market of degradable melt spun non woven fabric can be expected in the future.