FILTER MEDIA

• 1. Nominal vs Absolute removal efficiency

  Nominal Removal Efficiency:

  Nominal removal efficiency provides an approximate or nominal indication of the filter's ability to remove particles or contaminants of a certain size. It is often expressed as a percentage and is based on the manufacturer's specifications or design intentions.

  Nominal removal efficiency does not guarantee the removal of all particles or contaminants of a specified size; rather, it suggests the filter's general performance under typical operating conditions. It may be used as a rough guideline for comparing different filters but should not be relied upon as an exact measure of filtration performance.

  Absolute Removal Efficiency:

  Absolute removal efficiency represents the filter's actual ability to remove particles or contaminants of a specific size under defined conditions. It is determined through rigorous testing methods and represents the filter's performance in removing particles of a particular size with a high degree of accuracy.

  Absolute removal efficiency provides a more precise measure compared to nominal removal efficiency and is often used in situations where precise filtration requirements are necessary, such as in critical applications like pharmaceuticals, electronics manufacturing, or cleanroom environments. This measure is more reliable for determining the filter's effectiveness in removing particles or contaminants of a specified size, as it accounts for variations in operating conditions and filter performance.

  In summary, while nominal removal efficiency provides a general indication of filter performance based on manufacturer specifications, absolute removal efficiency offers a more precise measure determined through rigorous testing methods under defined conditions.

• 2. What are the differences between polypropylene (PP), polyester (PE), bag filter media?

  Polypropylene (PO or PP) and polyester (PE) are two common materials used in bag filter media for liquid filtration, and they have several differences:

  Chemical Resistance:

  Polypropylene (PO or PP): PP offers excellent chemical resistance to a wide range of acids, alkalis, and organic solvents. It is particularly suitable for applications involving aggressive chemicals.

  Polyester (PE): Polyester also provides good chemical resistance but may not be as resistant to certain aggressive chemicals compared to PP. However, it offers better resistance to higher temperatures. (Please fer to datasheets for Maximum Temperatures

  Temperature Resistance:

  Polypropylene (PO or PP): PP has lower temperature resistance compared to polyester. It is typically suitable for applications with temperatures up to around 200°F (93°C).

  Polyester (PE): Polyester can withstand higher temperatures than PP, making it suitable for applications where elevated temperatures are present, typically up to 300°F (149°C) or higher.

  Mechanical Strength:

  Polypropylene (PO or PP): PP has good mechanical strength and is resistant to tearing and puncturing, making it durable for filtration applications.

  Polyester (PE): Polyester also has good mechanical strength and can withstand higher stress and strain compared to PP.

  Mechanical Strength is generally only a concern when a filter bag is being used in an open filtration application. When installed in a vessel the bag is supported by a stainless steel perforated basket.

  Micron Rating and Filtration Efficiency:

  Both PP and PE can be manufactured to various micron ratings to meet specific filtration requirements. The micron rating indicates the particle size that the filter media can effectively capture. Both materials can achieve high filtration efficiency.

  Standard Felt Fiter Bags are Nominal Rated, approx. 70% to 80% removal efficiency at the stated micron size per pass. The actual result will be influenced by the solids loading and the article size distribution.

  Cost:

  Polypropylene (PO or PP): PP is generally more cost-effective compared to polyester, making it a preferred choice for applications where cost is a significant factor.

  Polyester (PE): Polyester tends to be slightly more expensive than PP due to its higher manufacturing costs and superior temperature resistance.

  In summary

  The choice between polypropylene (PO or PP) and polyester (PE) bag filter media depends on factors such as chemical compatibility, temperature requirements, and cost considerations specific to the filtration application.

• 3. What is Extended Lift Filter Media ?

  Available in either polypropylene or polyester needle felt constructions, the extended-life filter bags boast an increased thickness of filter material, substantially enhancing dirt holding capacity and extending lifespan by two to five times compared to standard needle felt filter bags. These attributes translate to significant reductions in operating costs. Furthermore, the needle felt material, characterized by smaller diameter fibers, delivers a more porous filter material without compromising on low initial differential pressure.