Pollutant emission is a health hazard in many urban and rural areas worldwide. Solid particulates from industrial byproducts ranging in size from 0.25 to 1 micron are inhaled, and often retained, by humans. Proper filtration media can help control these particles and reduce health risks in the general population.
Nonwoven fabrics account for almost 70% of all filter media for air filtration. Air filtration products are designed to remove the particulates and microorganisms from the air with processes based on the particle characteristics and filter construction. In industrial applications, the main objective of air filtration products is to maximize the retention of particles while minimizing the loss of energy to the air stream.
There are two types of nonwoven fabrics that work well for air filtration: dry laid and wet laid. Dry laid processes usually produce filtration media that has high dirt-holding capacities. The dry laid meltblown process is often used to produce filtration media that has no binders or adhesives, resists shedding and has a uniform porosity. The wet laid processes produces media typically using binding agents. Determining whether or not to use wet laid or dry laid processes is dependent on the final use of the filter and end-use characteristics like temperature and size of the particles to be filtered.
Choosing the type of nonwoven filter media you need is dependent on a variety of the end-use needs, such as:
- Air flow volume required
- Air flow velocity
- Particle size and weigh
- Electrostatic property of particles
Working with a nonwoven manufacturing to evaluate the filtration performance of sample fabrics is always a good bet when deciding on the type of filter media you need manufactured.
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