The spinning technology mainly includes melt extrusion amount, drafting hot air flow rate and melting temperature.
1.Melt extrusion. The extrusion volume of polymer melt produced by melt spraying plant can affect the linear density and yield of fiber.The greater number of grams per minute of polymer melt extruded from the spinneret hole, the thicker the fiber. Therefore, on the premise of ensuring fiber fineness, increasing the number of spinneret holes is very necessary to increase the output of melt blown nonwoven fabric.
2.Drafting hot air flow rate. As the main technological parameter, the flow rate of secondary hot melt directly affects the fineness of fiber during injection. In industrial production, it is usually possible to use rapidly developed ventilated hot air to compensate for the constant change in the diameter of fiber cells caused by the increase in polymer extrusion time, that is, the flow rate of the secondary hot air must match the polymer extrusion.
3.Melting temperature. The melt-blowing temperature of melt blown nonwoven fabric is the working temperature, which can be used to adjust the melt viscosity of the nozzle of polymer melt. The melting temperature is usually above the melting point of PP resin, which is in the viscous flow state. When other process conditions are held constant, the melt flow will have better liquid droplets if the melt viscosity of the polymer is reduced. Therefore, the microfibers can be easily obtained by melting and spraying high MF polymer chip materials. However, too little melt viscosity can cause excessive melt to flow, extend, and then fly into the air in the form of short microfiber that cannot be collected, which is a phenomenon known as “flying” in the melt blowing process.