Some of the major challenges in producing high-quality meltblown nonwoven fabric include:
Fiber size and uniformity
It is difficult to meltblown nonwoven fabric machine produce very fine fibers with narrow fiber size distribution. Variations in fiber size and uniformity can affect the properties of the meltblown web. Tight control of extrusion and blowing conditions is required to produce uniform ultrafine fibers.
Basis weight variability
It is challenging to produce meltblown webs with uniform basis weight across the web width and length. Variations in basis weight can lead to product performance inconsistencies. Precise control of fiber throughput and the spinning/blowing process is needed to minimize basis weight variability.
Fiber entanglement
Achieving the desired degree of fiber entanglement with good web integrity requires balancing the spinning and blowing air pressures. Insufficient fiber entanglement leads to poor web strength while over-entanglement leads to high pressure drop. Optimizing the meltblowing process parameters is key to producing webs with the target fiber entanglement.
Managing high airflow
Large volumes of high-temperature air are required to attenuate and blow the fibers onto the collector belt. This requires large blowers and ductwork to handle the airflow which can be difficult to control and maintain at the desired conditions. Maintaining the proper airflow balance is crucial for meltblowing.
Heat management
The meltblowing process involves supplying, heating and removing large amounts of air which requires careful management of the heating/cooling systems. Failure to properly control temperatures in the process can lead to issues like fiber quality problems, polymer clogging, belt overheating, etc. Efficient heat exchange equipment and control systems are needed.
Fiber blow-off
Some of the fibers may blow off from the collector belt before bonding leading to yield losses and waste. Proper hoods, suction systems, and web handling techniques are required to minimize fiber blow-off from the belt.
Bonding and strength
Achieving adequate web bonding and strength can be challenging especially at high web weights or with incompatible polymers. The bonding method and process conditions must be optimized to meet the strength and durability requirements of the meltblown fabric.
