Aokai manufactures baghouse filter media, filter bags and filter cages.

Filter Media

Aokai Design & Manufacture Advantages

Custom Filter Media Design & Manufacturing

Aokai is a baghouse filter media manufacturer and supplier, and we are enthusiastic about helping customers achieve the highest and longest-lasting filtration efficiency. By designing and manufacturing filter media in-house, Aokai ensures:

Custom Filter Media Design

Every industrial dust collection application is different and unique. Based on customers’ unique requirements, industry-specific characteristics, and filtration operating conditions, we custom design and manufacture filter media that best suits customers’ unique dust collection requirements.

Quality Raw Material

We source raw materials from some of the most reputable fabric suppliers in the industry, including DuPont, Teijin Group, Toray Industries, and Lenzing Group.

Advanced Manufacturing Equipment & Technology

Partnering with a reputable and industry-leading needlefelt equipment manufacturer from Germany, Aokai operates two advanced needlefelt production lines. From fiber opening to blending, carding, web forming, crosslapping, needle punching, filter media treatment, and ePTFE lamination, we manufacture baghouse filter media in-house to ensure the highest manufacturing standards.

Stringent Quality Control Measurements

In addition to the employment of advanced manufacturing technologies, numerous quality control procedures are in place to ensure production standards, and filter media homogeneity and uniformity.

On-Time Delivery

With two advanced and fully automated needlefelt production lines, and a capacity of 40 million square feet of filter media manufacturing capacity per annum, we can handle all customer requirements and custom orders, small or large.

Filter Media Manufacturing

Aokai Filter Media

Filter Media Characteristics

Aokai specializes in dust collection processes in asphalt mixing, chemicals, cement, metals, power generation, waste-to-energy, renewable energy, woodworking, and many other demanding industries. We provide custom filter media solutions for abrasive, corrosive, high-temperature, and explosive dust filtration. The filtration function of filter media is determined by the filter media material, filter media construction (woven or nonwoven), and filter media treatment (refer to the blog “Filter Media Basics” for more information):

Filter Media Material

Each filter media has its own unique filtration characteristics. Choosing the right filter media with its corresponding characteristics that are best suited for your application can help boost the performance and longevity of your dust filtration system. Learn more about filtration characteristics of the most commonly used filter media available.

Polyester is an economical option with excellent filtration properties and is widely available. This makes polyester the most common filter media used across many industry applications. Polyester has an operating temperature limit of 135°C (275°F) and comes in both needlefelt and woven media. Both needled felt and woven polyester can be treated with several finishes and membranes to increase the efficiency and performance in various operating conditions.

As a filter media, acrylic can handle moisture better than polyester and has a higher temperature rating. If your operating temperature is less than 130°C (266°F), and with more than 10% moisture, you could use acrylic.

PPS, also known by the proprietary name Ryton or Procon, is commonly used in dust collection applications that require excellent resistance to acids and alkalis. Out of all the options for high-temperature filter media, PPS has the lowest tolerance to heat in comparison with others but handles chemicals better. PPS can be used in applications with maximum continuous operating temperatures of 190°C (375°F). PPS filter media is commonly used in carbon black, chemicals, cement, asphalt, coal-fired boilers, and incinerator applications.

Aramid, also known as Nomex, is used in applications with high temperatures and has excellent filtration and abrasion properties. The operating temperature limit for aramid is 204°C (400°F), which makes it a great choice for applications such as asphalt batch plants, furnaces, and dryers. Both needled felt and woven aramid can be treated with several finishes and membranes to increase filtration efficiency and performance in various operating conditions.

P84 (polymide) dust collector filter media is used in operating conditions of a maximum 260°C (500°F). P84 performs well under dry high heat temperatures and can even withstand some elevated levels of moisture. P84 has a slightly better resistance to acids than PPS. P84 filter media is used in waste-to-energy, power generation, lime kilns, smelting, glass & ceramic, and cement applications.

PTFE, otherwise known as Teflon, is one of the most expensive dust collector filter media used in pulse-jet dust collectors. PTFE is considered a premium filter media because it can deliver superior dust cake release, withstand high heat temperatures of up to 260°C (500°F), and resist acids and moist heat. Cement, steel foundries, coal-fired power plants, carbon black, steel, and energy applications are just a few examples of industries that use PTFE as a filter media.

Fiberglass is often used in baghouses with temperatures ranging up to 260°C (500°F). Since fiberglass media is typically woven, the efficiency of plain fiberglass media is lower than most felts. However, there are several different membranes and finishes that can be added to fiberglass to increase filtration efficiency and performance in harsh baghouse conditions. These finishes and membranes make fiberglass a versatile media for applications with high temperatures. Fiberglass media is widely used in power generation, cement, and agriculture industries.

Each filter media has its own unique characteristics. By blending various fibers in order to achieve excelled physical and filtration characteristics, Aokai designs, tests, and manufactures blend filter media solutions that help customers meet their unique dust collection challenges and requirements. Contact Aokai for your custom filter media requirements, today!

Filter Media Construction

Filter media construction refers to the way that filter media are constructed. It is commonly categorized as woven and nonwoven. To further enhance filtration efficiency and filter bag durability, a dual-density felt structure is often used to construct filter media.

Nonwoven

Nonwoven fabrics are made using a process that involves first joining the fibers together in ordered or random patterns, and then coupling the layers of nonwoven with a polymer to give life to a porous material suitable for filtration. The most commonly used filtration nonwoven raw materials include aramid, PTFE, PPS, fiberglass, acrylic, polyester, polymide, and mixed fiber blends. Generally, they are used with higher energy cleaning systems such as pulse-jet dust collectors. The four most widely used nonwoven fabrication processes are:

  • Needlefelting
  • Spunlace (Hydro-entangling)
  • Spunbond
  • Meltblown

Within the needlefelting category, a dual-density felt structure is often used to construct filter media. In a genuine dual-density filter media, two media of different densities are separated by a scrim in the middle that provides dimensional stability and a densified central core which improves filtration efficiency by minimizing dust migration through the felt. The scrim structure offers a clear advantage over unsupported felts (without scrim) which are produced in a single process with a homogeneous fiber blend and filtration characteristics only.

Woven

Woven fabrics are made by weaving single strands of materials such as monofilament or fibrillated yarns on a loom with a definite repeated pattern. The most commonly used filtration woven raw materials include polyester and fiberglass. Generally, they are used with low energy cleaning systems such as shaker or reverse air baghouses.

Filter Media Treatment

Different fibers provide each media with different dust filtration characteristics. Filter media can be further treated to improve their filtration efficiency and performance, such as lengthened filter media life cycle, better dust cake release, reduced valve pulsing, more consistent airflow, reduced differential pressure, and reduced downtime and maintenance.

Singeing is a finishing process where the surface of the filter media is exposed to a flame or hot gas to burn off the fine and straggly fibers in order to provide a uniform and smooth surface area, which improves dusk cake release, enhanced filtration efficiency, and better air permeability.

The singeing process typically involves passing the fabric over an open flame or through a heated chamber. The heat singes off the protruding fibers without damaging the main structure of the fabric. The process parameters, such as speed and temperature, are carefully controlled to achieve the desired level of smoothness and finish.

You can typically see this process done on polyester, polypropylene, acrylic, aramid, aramid, and P84 felts.

Calendering, also known as Glazing, is the high-pressure pressing of the fabric by rollers to flatten or smooth the material. Calendering pushes the surface fibers down onto the body of the filter media.  Calendering can be applied to various media such as polyester, polypropylene, and aramid. This is done to increase and uniform surface life, improve stability, and reduce shrinkage.

Coating, also known as resin treatment, involves immersing the filter media in natural or synthetic resin. This process helps lubricate the fibers, helps the fibers shed water and oil (hydrophobic & oleaphobic), and provides high-temperature durability.

ePTFE stands for expanded polytetrafluoroethylene, and it is a microporous membrane that is laminated to the filtration side of the filter media to enhance the filtration performance. The performance improvements include enhanced emissions control, easy dust cake release during the cleaning cycle, reduced cleaning energy cost, and higher collection efficiency due to its surface filtration characteristics.

Filter Media Treatment

Aokai Advantages

Why Choose Filter Media from Aokai

Aokai is enthusiastic about helping customers achieve:

Custom designed and manufactured filter media;
Longer filter media & filter bag life cycle;
Reduced production & maintenance downtime;
Lower total cost of ownership (TCO);
Higher dust collection efficiency & dust emission standards.

Filter Media Manufacturing

filter media 7 crosslapping