Have you seen the making of sugary cotton candies at amusement parks and fairs? Melt blowing technology is a high-tech version of the candy-making process because the procedure is somewhat similar. Melt blowing technology is a conventional method of manufacturing micro and nanofibers using plastic. Manufacturers follow the melt blowing method to produce melt-blown fabrics from polypropylene strands. The materials are called melt-blown nonwoven fabric because, unlike cotton and wool, we do not weave them after forming the yarn.
Production Process of Melt Blowing Technology
Below is the production process of melt blowing technology:
Slice storage trough → air flow conveying device → screw extrusion melting → filtration → metering →die head → spinner (hot air) → laying net → static electret → coiling.
- Slice storage trough
The raw material will be stored on the slice storage trough for future use.
- Airflow conveying device
With the airflow conveying device, air converges with the fiber raw material as it emerges from the die.
- Screw extrusion melting
The melt-blown extrusion process is a single-step process that uses high-speed airflow to blow molten thermoplastic resin from the extruder die onto filters or so-called receiving screen.
The melt-blown filter is a cylindrical cylinder made of polymer fibers to melt blow and collect the rotating spindle. The polymer travels through the tubular path and is blown out through the opening, and the air drags the polymer vapor to form fibers.
The metering device is a positive displacement pump designed to deliver a constant volume of clean polymer mixture to the die assembly. There are two counter-rotating gears in the pump that mesh with each other. As the gears rotate, they draw molten polymer from the suction side or suction side of the pump and deliver it to the pump’s discharge side. The output of the metering pump is then fed to the die head.
The die head is a key component to determine the uniformity of the melt-blown material web produced by the machine. The die is a hollow, tapered metal part with tight tolerances and wide tolerances, which contains many holes through which molten polymer will form a melt-blown nonwoven fabric.
- Spinner (hot air)
In this process, high-speed heated air is supplied to the extruded fiber output from the die connector. The pressurized airflow is provided by the air compressor, which first passes through the heat exchanger to drive off the gas or the electric furnace to deliver the air temperature to a particular range.
- Laying Net
The high-speed hot airflow in the spinning step drives the molten polymer extruded through the die orifice to form polymer fibers, and then they are further extended in the airflow. Simultaneously, the fibers are blown together in a semi-molten state while being stretched and directed toward the collector screen. The hot air flow also causes secondary air to be drawn from the surrounding ambient air. It helps to cool and solidify the collected material web formed on the collector; a coiled metal screen connected to the conveyor belt. The fibers are cured and randomly placed on the collector and are combined to form a web by entanglement and bonding of the fibers.
- Static Electret
The fibers are sprayed from the spinneret to the web forming machine, then passed through the electrostatic assist device, and finally wound in the cardboard core of the winder for bonding and slitting.
The coiling machine adopts automatic coiling, and the melt-blown cloth is packaged in rolls. Melt-blown nonwovens are characterized by ultra-fine fibers. The minor fiber diameter can reach 0.5Lm, generally between 1~5Lm. The finer the fiber, the better the melt-blown cloth’s quality.
Applications of Melt Blowing Technology
The density of web fibers of the melt-blown fabric is relatively high due to the blowing of the high-velocity air. Thus, the fibers are dense but fine, which is why they are suitable for all industries filtrating particles and fluids. Below are some of the industries which require melt-blown fabric generated from the melt-blown process:
As mentioned already, there is no better alternatives to melt-blown fabrics when it comes to filtrating gases and liquids. Specifically, melt-blown fabrics can be employed for water filtration, air purifying, smoke and fume filtrating, room filtrating, etc.
Melt-blown fabrics are capable of absorbing heavy liquids like oil, and this makes them the perfect solvent. That is why; they are now heavily utilized to retain oils and other pollutants from rivers and oceans. Besides this, they form the base material for wipe cloths as well.
The absorption power of the melt-blown nonwoven fabrics is impressive, and that is why it is now employed in producing hygiene products like diapers, female sanitary pads, etc.
Without melt-blown fabrics, you cannot produce any surgical masks or medical masks. In other words, when made by the melt-blown process, melt-blown fabrics form the primary material for generating high quantities of disposable masks.
With the development trend of the high-end melt-blown nonwoven market, technical improvement is of great importance for melt-blown fabric manufacturers. M-sur is one of the most reliable manufacturers specializing in all kinds of melt-blown nonwoven fabric, including PP particles, electret master batches, and PE particles. With years of experience, M-sur is committed to the technical improvement of the products. If you wish to source the melt-blown nonwoven fabric for manufacturing industrial products, then you can take a look at m-sur.